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A Comprehensive Comparison of Offline and On-line Pulse Jet Baghouse Filters

Air pollution control technology plays a crucial role in modern industrial production. As environmental regulations become stricter, industries increasingly rely on dust collection devices. Pulse bag dust collectors have emerged as a preferred solution for dust removal because they perform efficiently.Among these, Off-line Pulse Jet Baghouse Filters stand out as an effective option.

 

These dust collectors fall into two categories: online and offline. By understanding the features and applications of both types, businesses can optimize their dust removal systems for better design and effectiveness.

Off-line Pulse Jet Baghouse Filters

Working Principle

The offline pulse bag dust collector features a chambered design. When cleaning is needed, control valves close the airflow to a specific chamber, stopping the filtration process. Subsequently, a pulse blowing device cleans the inactive chamber, using the powerful back pressure of compressed air to quickly remove dust from the filter bag's surface, allowing it to fall into the hopper. Once cleaning is complete, the chamber resumes filtration, and the others follow suit. This method ensures that some chambers remain operational, maintaining continuous dust removal.

 

Structural Characteristics

The off-line pulse jet baghouse filter  mainly consists of the following parts:

 

  • Inlet

  • Filter bags

  • Cage

  • Flower plate

  • Hopper

  • Pulse cleaning device (including pulse valves, blowing pipes, air tanks, etc.)

  • Control system

  • Outlet

 

Its chambered structure gives each chamber independent control valves and pulse cleaning devices. This design enables each chamber to clean independently. Furthermore,offline pulse bag dust collectors usually have a larger hopper. This hopper collects and stores the dust that has been removed. It also includes baffles to prevent secondary dust emissions.

 

Application Fields

Off-line pulse jet baghouse filters are common in heavy industries like steel, cement, power, and chemicals. They are especially effective at handling large air volumes, high dust concentrations, and sticky dust. For example, in the steel industry, these collectors can tackle high gas volumes and dust concentrations in sintering machine tail dust removal systems.

 

Advantages and Disadvantages

Advantages

  1. High Cleaning Efficiency: The offline cleaning method ensures complete removal of dust from the filter bags, maintaining filtration efficiency and prolonging service life.

  2. Strong Adaptability: The chambered design allows stable operation in high dust concentration and humidity environments.

  3. Continuous Operation: While some chambers are being cleaned, others continue filtering, ensuring system continuity.

  4. Low Energy Consumption: The efficient cleaning process reduces operational resistance, minimizing energy use and maintenance costs.

 

Disadvantages

  1. Complex Structure: The chambered design and numerous valves increase the complexity and manufacturing cost of the equipment.

  2. Large Footprint: Compared to online dust collectors, offline pulse bag dust collectors require more installation space.

  3. High Initial Investment: The complex structure and multiple components lead to higher initial investment costs.

  4. Complex Maintenance: The chambered structure and numerous components make maintenance and repairs relatively complicated.

 

Off-line pulse jet baghouse filters in an industrial setting, showcasing their chambered design and dust collection capabilities.

On-line Pulse Jet Baghouse Filters

Working Principle

The online pulse bag dust collector cleans while it filters. It uses high-pressure airflow to spray the surface of the filter bags. This airflow creates vibrations and impacts that dislodge dust into the hopper. The cleaning process does not require downtime. As a result, it ensures continuous gas flow and effective dust removal.

 

Structural Characteristics

The on-line pulse jet baghouse filter primarily consists of the following components:

 

  • Inlet

  • Filter bags

  • Cage

  • Flower plate

  • Hopper

  • Pulse cleaning device

  • Control system

  • Outlet

 

All filter bags install in one or a few chambers. This design simplifies the overall structure and reduces the number of valves and mechanical parts. As a result, it lowers complexity and costs. Additionally, on-line pulse jet baghouse filters usually have a smaller footprint. This feature makes them suitable for industrial sites with limited space.

 

Application Fields

On-line pulse jet baghouse filters are common in many industrial sectors. They work especially well with medium concentrations and ordinary dust. For example, in the building materials industry, such as in brick and tile production and lime kiln dust removal, these collectors efficiently remove dust generated during processes. This ensures that emissions meet environmental standards.

 

Advantages and Disadvantages

Advantages

  1. Simple Structure: The design is straightforward, without complex chamber structures or valve control systems.

  2. Low Cost: Manufacturing and maintenance costs are relatively low, making it suitable for budget-constrained scenarios.

  3. Convenient Operation: Cleaning operations do not require downtime, simplifying the operational process.

  4. Small Footprint: The compact design is ideal for environments with space constraints.

 

Disadvantages

  1. Limited Cleaning Effectiveness: The online cleaning method may not completely remove dust from the filter bags’ surface.

  2. Not Suitable for Sticky Dust: For highly sticky or humid dust, the online cleaning method may lead to filter bag clogging, affecting efficiency.

  3. High Operational Resistance: Prolonged operation may increase system resistance, impacting dust removal efficiency.

  4. Frequent Maintenance: Although structurally simple, more frequent cleaning operations may lead to increased wear on filter bags and other components, raising maintenance costs.

 

Differences Between Off-line and On-line Pulse Jet Baghouse Filters

Differences in Working Principles

Offline pulse bag dust collectors stop filtration by cutting off airflow to one or more chambers using control valves. This allows for cleaning before they resume filtration. In contrast, on-line pulse jet baghouse filters clean while all chambers are filtering. This design ensures continuous gas flow.

 

Differences in Structural Characteristics

Off-line pulse jet baghouse filters have a chambered design with independent control valves. This design leads to a complex structure and a larger size. On the other hand, on-line pulse jet baghouse filters have a simpler design. Their compact size makes them suitable for applications with limited space.

 

Differences in Application Fields

Off-line pulse jet baghouse filters work well in complex conditions with high dust concentration and humidity. In contrast, on-line pulse jet baghouse filters are better for medium dust concentrations and ordinary dust handling.

If you wish to achieve efficient air filtration in dust handling processes, Darko can provide you with the best solution. Our professional team will assist you in selecting the most suitable dust collection equipment based on your specific needs. Feel free to contact us anytime!

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Maximizing Efficiency with Roots Blowers

In the cement industry, selecting the appropriate blower, such as Roots blowers, is crucial for production efficiency. Recently, Darko gained valuable experience while working with clients that we would like to share. 

Wide range of uses of Roots Blowers

A Roots blower operates as a positive displacement rotary blower, utilizing two rotor-shaped blades to compress and transport gas through relative motion within a cylinder. This design features a simple structure, which facilitates easy manufacturing. Consequently, it is well-suited for gas conveying and pressurization in low-pressure applications. Additionally, it can effectively function as a vacuum pump.

 

Roots blowers are widely used in various fields due to their stable performance. They find applications in wastewater treatment, water supply, pharmaceutical and chemical industries, flue gas, dust handling, and aquaculture. Furthermore, they are involved in cement transport and desulfurization and dust removal industries, serving essential functions such as gas conveying, pressurization, and ventilation.

Background

Not long ago, a northern cement plant ordered our composite mixer and requested to pair it with a vortex blower. Previously, our composite mixers and air-chain conveyors were typically equipped with Roots blowers, so we were not very familiar with the technical parameters and performance of the vortex blower.

At the same time, a southern cement company reported that when using our FUK800×60 meter air-chain conveyor, the throughput reached 410-420 t/h, but dust began to spill, failing to meet the designed capacity of 650 t/h. This prompted us to quickly visit the site to resolve the issue.

On-Site Investigation and Analysis

Technical Parameter Review

Our technical team arrived at the site. We reviewed the installation and technical parameters of the equipment. We found that all agreed-upon indicators were met. However, the blower in use was not the Roots blower we provided. Instead, it was a vortex blower purchased by the client.

Testing Issues

During the testing process, the throughput remained stuck between 410-420 t/h, accompanied by dusting issues. After careful observation, technicians noticed that opening a viewing port about ten meters from the discharge increased the material level, allowing throughput to rise to 500 t/h. However, dusting issues reappeared under full load, creating concern.

Large blue and yellow industrial fans, type Roots blowers, showing their importance and efficiency in industrial applications.

Response Strategy

Blower Replacement

We learned that another nearby company could meet their design requirements with a different blower. Therefore, we decided to take a dual approach:

  1. Replace the blower with a Roots model that closely matched the technical parameters.
  2. Continue to explore the performance of the vortex blower.

Adjusting Variable Frequency Motor Settings

We adjusted the vortex blower. We discovered it used a variable frequency motor. The technical parameters showed that pressure and airflow varied at 50HZ and 60HZ. Therefore, we decided to increase the motor frequency to 60HZ for testing. This change allowed the throughput to easily exceed 500 t/h. Eventually, it reached 680 t/h during adjustments.

Blower Comparison Analysis

Roots Blower vs. Vortex Blower

Through this experience, we conducted a comparative analysis of the two blowers:

  • Roots Blower: Offers stable pressure and airflow, with a power rating of 15 kW, making it suitable for applications with high pressure requirements.
  • Vortex Blower: Pressure and airflow vary with different frequencies, with a power rating of around 20 kW. It can be used in various applications but may not be as stable as Roots blowers in certain conditions.

Conclusion and Recommendations

Based on our practical experience, the Roots blower shows better technical performance and energy efficiency. This makes it a better fit for Darko's composite mixers and air-chain conveyors. The vortex blower can serve as a replacement in some situations. However, the Roots blower is preferable when high pressure stability is needed.

If you have any questions about blower selection or would like to learn more about our products, please feel free to contact us at Darko. Together, we can explore ways to improve production efficiency in the cement industry!

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Bucket Elevators: Key to Modern Transport

What is a bucket elevator？

Bucket elevators are popular vertical conveying devices. They primarily elevate powdered, granular, and small block materials. These elevators have high conveying efficiency, a compact structure, and a small footprint. They can lift materials to heights of 40 to 100 meters while remaining reliable. This reliability makes them essential in various industries, such as power generation, cement, metallurgy, machinery, chemicals, light industry, and agriculture.
 

Moreover, bucket elevators are widely used in the cement industry. Their small footprint, simple structure, large capacity, high lifting height, and low energy consumption contribute to their popularity. They are critical at different stages, including raw material storage, transportation, grinding systems, clinker feeding, cement grinding, and packaging. In modern large-scale cement production lines, bucket elevators are vital components in key positions.

Nantong Darko’s Expertise

Nantong Darko has ten years of experience in machinery manufacturing. We use advanced design principles to create our products. We also select high-quality steel and components. Additionally, we strictly control manufacturing precision to ensure reliable operation of our bucket elevators. Our product range includes NE type, TD type, TH/HL type, and dewatering scooping bucket elevators.

Classification of Bucket Elevators

1. By Layout

  • Vertical: The most common layout for conveying materials straight up.

  • Inclined: Suitable for scenarios requiring material elevation at a certain angle.

 

2. By Discharge Method

  • Centrifugal: Utilizes centrifugal force for discharge, suitable for conveying small, free-flowing materials, such as dry powders.

  • Gravitational: Relies on the weight of the material for discharge, suitable for large, heavy, and abrasive materials like ores and stones.

  • Mixed: Combines characteristics of both centrifugal and gravitational discharge methods, offering a wider application range.

 

3. By Feeding Method

  • Scoop: The bucket scoops material from the bottom; commonly used for conveying loose powders, granules, and small blocks.

  • Injection: Material is directly injected into the bucket, suitable for large and abrasive materials.

 

4. By Bucket Structure

  • Shallow Bucket: Wider and shallower bucket suitable for conveying damp, easily clumping, and poorly flowing materials.

  • Deep Bucket: Narrower and deeper bucket ideal for dry, loose, and easily spilled materials.

  • Triangular Bucket: With slanted walls, typically used for conveying large items.

 

5. By Traction Component

  • Belt: Low cost, light weight, and smooth operation, but with lower strength, not suitable for high-temperature or abrasive materials.

  • Steel Chain: High strength and wear resistance, suitable for high-temperature, heavy load, and abrasive materials.

 

Structure of Bucket Elevators

  1. Bucket: Used for loading and elevating materials.

  2. Traction Component: Such as belts or chains, which drive the movement of the buckets.

  3. Drive Device: Provides power, typically including motors and reducers.

  4. Upper and Lower Drums (or Sprockets): Change the direction of motion of the traction component.

  5. Casing: Forms a closed transport channel to prevent material spillage and dust escape.

  6. Tensioning Device: Adjusts the tension of the traction component to ensure normal operation.

Working Principle of Bucket Elevators

Bucket elevators scoop material from the storage area below with the buckets and elevate it to the top as the traction component (such as a conveyor belt or chain) moves. At the top, the bucket flips over and dumps the material into the receiving chute.

 

In belt-driven bucket elevators, the drive belt is typically made of rubber and installed on the drive drums and redirecting drums. Chain-driven bucket elevators usually have two parallel drive chains, with a pair of driving sprockets on either the top or bottom, and a pair of redirecting sprockets on the opposite side. To reduce dust escape, bucket elevators are typically equipped with a casing.

 

Working Principle of Bucket Elevator

Precautions for Using Bucket Elevators

  1. Strictly follow the principle of “no-load start, empty stop.” Ensure there is no material load before starting, and only feed materials once the machine is running smoothly. Empty the machine before stopping to avoid overload during the next start.

  2. Feed uniformly to ensure unobstructed discharge. If a blockage is found, immediately stop feeding and address the issue.

  3. Keep the bucket belt centered in the casing. If it drifts or becomes too loose, adjust it promptly using the tensioning device.

  4. Prevent large foreign objects from entering the casing to avoid damaging the buckets. A metal grid can be installed at the feed inlet to block fibrous impurities like straw and rope.

  5. Regularly check the tension of the bucket belt and the connection between buckets and the belt. If any looseness, detachment, misalignment, or damage is found, repair or replace it promptly to avoid more severe failures.

  6. In case of sudden shutdown, first clear any accumulated materials in the casing before restarting to prevent excessive load during startup.

 

Understanding the classification, structure, principles, and precautions of bucket elevators is crucial. This knowledge ensures safe, efficient, and stable operation. If you have questions or need assistance, please contact us. Over the past ten years, Darko has introduced many innovations in vertical conveying technology. We have achieved significant progress in high-performance bucket elevators. Our experience and pioneering spirit have made us industry leaders in the design and manufacture of these elevators.

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Efficient Roller Press Solutions

What is a roller press used for?

The roller press, also known as a squeeze mill, roller mill, or double roller machine.A roller press is a grinding device used in industrial applications, particularly in cement production. It consists of two counter-rotating rollers that compress and grind the material. This process significantly reduces the particle size of the material, making it an efficient alternative to traditional grinding methods.

The roller press has high grinding efficiency, low energy consumption, and high output, making it widely used in the cement industry. However, during operation, various issues arise due to factors such as design, usage, and external conditions. These problems lead to poor working conditions, inadequate feed control, and hydraulic system failures, all of which negatively affect the performance of the roller press. To address these challenges, we analyze the root causes and implement improvements across multiple aspects, including design and usage. As a result, we optimize the modification process, enhance efficiency, and achieve better operational results.

 

I.Role of the Roller Press in Cement Plants

In cement plants, operators use the roller press to grind clinker and other raw materials into fine powder. Typically, they employ it alongside other grinding systems, such as ball mills, to enhance overall efficiency and reduce energy consumption. Furthermore, the roller press's capacity to manage high pressure and produce fine products makes it an essential component of modern cement production.

 

II.Differences Between Roller Press and Ball Mill

The primary difference between a roller press and a ball mill lies in their grinding mechanisms. A roller press compresses the material between two rollers under high pressure, resulting in lower energy consumption and higher efficiency. In contrast, a ball mill relies on the impact and friction of balls to grind the material, which typically consumes more energy. Therefore, roller presses usually perform better in terms of energy efficiency and product fineness.

 

III.Skew Issues in Roller Presses

Skew refers to the misalignment between the rollers of the roller press and may arise from mechanical wear or improper installation. This misalignment can lead to uneven pressure distribution, which ultimately reduces grinding efficiency. Therefore, regular maintenance and proper alignment are crucial for minimizing skew and ensuring the optimal performance of the roller press.

 

IV.Analysis of Issues with Roller Presses

1. Fine Powder Content at the Outlet

The fine powder content at the outlet of the roller press, also known as first-pass yield, directly reflects the effectiveness of the pressing process. However, many companies overlook this critical aspect. Testing samples from various enterprises revealed that the German BHS roller press achieved an outlet fineness of 33% on a 0.9mm sieve and 64% on a 0.08mm sieve (with 36% below 0.08mm). In contrast, many of these machines do not reach similar results.

A series of images showing different types of cement, emphasising the effectiveness of the pressing process and the importance of fines content.

2. Working Pressure

The pressing force is the most fundamental parameter determining the effectiveness of the roller press. To calculate the total force F (in kN) of the roller press, we use the formula:

where:

  • n= number of hydraulic cylinders
  • S= effective area of the hydraulic cylinder (m²)
  • = hydraulic system pressure (MPa)

Moreover, the average roller pressure

D⋅B⋅sinα

Here:

  • = diameter of the grinding roller (m)
  • = effective width of the grinding roller (m)
  • α = pressure angle, also known as the bite angle (°)

Projected Pressure Calculation

In addition, the projected pressure PT (in kN/m²) is calculated using:

Impact of Maximum Roller Pressure on Pressing Efficiency

In practice, the maximum roller pressure significantly affects the pressing effect. Specifically, when the line connecting the centers of the two rollers is set at 0 degrees, the pressure angle starts at 8.3 degrees and ends at -1.6 degrees. Notably, the maximum peak pressure occurs at 1.5 degrees, slightly exceeding twice the average pressure.

 

Moreover, the hydraulic system of the roller press plays a crucial role, as it provides the dynamic roller pressure necessary to compress the material. This system consists of various components, including the oil station, hydraulic cylinders, nitrogen bags, solenoid valves, overflow valves, pressure gauges, oil lines, and control cabinet. If the configuration lacks damping adjustment valves and stroke adjustment valves, it cannot achieve optimal pressing results. Therefore, in some cases, adding small nitrogen bags may prevent the displayed pressure from accurately reflecting actual pressure changes.

Four equipment images illustrating the relationship between pressing force and hydraulic system pressure and its effect on efficiency.

Nitrogen Bag Configuration and Pressure Management

  • The size of the nitrogen bags and the piping must be calculated based on the size of the hydraulic cylinders. Furthermore, using pipes that are too small will increase resistance. In a parallel setup, when one large and one small nitrogen bag are used, the small bag activates first, followed by the large bag. As a result, this process repeatedly suppresses the opening of the roller gap, which operates in a cycle of retracting, retracting, and advancing, ultimately resulting in low pressing efficiency.
  • Moreover, the pressures of the nitrogen bags are set at 8, 10, and 12 MPa, meaning that only one nitrogen bag operates within a specific range while the other two become ineffective. Although this theory of differential pressure was initially proposed by German engineers, it failed to achieve the expected results due to significant variations in material properties. Consequently, the Germans did not pursue this approach further.
  • In general, it is advisable to set the nitrogen bag pressure at 60-80% of the system’s minimum pressure. This approach ensures that when the system operates at its lowest working pressure, a certain level of safety is maintained between the nitrogen bags and the on-off valve. However, the system’s operational state must be monitored on-site to determine its effectiveness. If the oil temperature is too high or too low, it indicates that the system is not in good working condition, which severely impacts pressing efficiency.

 

3. Roller Speed

The roller speed of the roller press can be expressed in two ways: one is the circumferential linear speed V of the rollers, and the other is the rotational speed of the rollers. The circumferential linear speed is related to output, power consumption, and operational stability. Generally, higher roller speeds lead to increased output; however, excessively high speeds can cause greater relative sliding between the rollers and the material, resulting in poor engagement and increased wear on the roller surfaces, which negatively impacts the output of the roller press.

 

Currently, the typical roller speed ranges from 1.0 to 1.75 m/s, with some experts suggesting that it should not exceed 1.5 m/s. The linear speed of the rollers usually falls between 1.0 and 1.7 m/s, with most operating around 1.5 to 1.7 m/s, and some even reaching 2.0 to 2.2 m/s. It is crucial to prioritize the squeezing effect when selecting the speed; this effect should be based on actual sampling. If the speed is too high, the pressing time shortens, leading to increased vibrations in the equipment. The significant variations in force become difficult to control, resulting in excessive power consumption without achieving the desired pressing effect.

 

Four images showing metal rolls highlighting the important relationship between roll speed and extrusion effect and equipment stability.

4. Operating Gap and Material Properties

The operation of the roller gap is influenced by various factors, including the properties of the material (such as hardness, particle size, and moisture content), the form of the roller surface, the speed, the pressure, and the pressure control method. There are two ways to control the hydraulic cylinder pressure: constant pressure control and constant gap control. However, regardless of the method used, both are fundamentally flawed from a hydraulic perspective because pressure and gap continuously fluctuate.

 

The pressure gauge has a response time of 200 milliseconds, which complicates the control of the oil pump's pressure adjustments. This, in turn, affects the hydraulic cylinder pressure and subsequently the roller gap. As a result, there are two main issues: first, there is a lag in response; second, excessive pressure differentials occur. These factors hinder the stable operation of the roller press and negatively impact pressing efficiency.

 

Roller press operating current, pressure, roll gap curve

5. Feeding Device

Currently, most roller presses use a feeding device that directs material straight from the hopper into the roller gap, pulling the material between the two rollers. This process is commonly referred to as the "pull-in angle" of the roller press. However, controlling the flow from two directions is not feasible, as the adjustment range is limited, making it difficult to achieve precise and stable control. Additionally, the other two directions cannot be adjusted at all. As a result, issues such as material segregation and roller misalignment frequently occur, leading to unmanageable conditions.

 

Two images show a machine and its design drawing, highlighting the working principle and challenges of the roller press feeder.

V.Roller Press System Modification Plan

1. Replacement of Feeding Device

Replace the roller press feeding device with a new type of four-direction feeding system (patented technology) to control the material feed. This system allows for adjustment and control from two directions, enabling reasonable control of material flow. The other two directions can be adjusted to correct the lateral gap deviation between the rollers, reducing the impact of the material on the roller press and facilitating the formation of a stable material bed. This approach eliminates issues such as material segregation and roller misalignment, and it operates at a low hopper position, making it easier to adjust and control.

Two images showing a roller press and a machine with a crane, showing the application of industrial equipment.

2. Upgrading the Hydraulic System

We replaced the hydraulic system of the roller press, including components such as the oil station, overflow valve, pressure gauge, accumulator (nitrogen bag), and valve assembly. Additionally, we incorporated damping adjustment valves and stroke adjustment valves (patented technology) to make the hydraulic system flexible, rigid, and controllable.

 

During the research and development process, we conducted extensive field tests using a specialized high-precision pressure measurement device (1000 Hz) to collect and analyze data. We employed dedicated simulation software and complex mathematical models to successfully develop a dual-channel adjustable damping anti-vibration regulation mechanism, achieving a reasonable balance of rigidity and flexibility in the hydraulic system.

 

Workers use a specialized high-precision pressure measurement device (1000Hz) to conduct a large number of on-site tests, collecting and analyzing data.

3. Implementing PLC Control

We replaced the roller press hydraulic PLC and implemented four-directional control of the feeding device, utilizing a constant power control method for easier centralized operation. We configured the system with Siemens SIMATIC S7-1200, integrating Siemens SINAMICS drive products and SIMATIC human-machine interface products. The CPU comes standard with an Ethernet interface that supports various industrial Ethernet communication protocols, including PROFINET, TCP, UDP, and Modbus TCP.

 

Our company developed this technology through mathematical modeling, gathering extensive field data during the research and development process. We employed specialized simulation software and complex mathematical models, which have been validated through practical application.

 

VI.Case Studies

1. Chao Lake Hengxin Cement Co., Ltd.

Since the modification in August 2020, production efficiency has increased from 200 tons/hour to 290 tons/hour, with energy consumption controlled at 22 kWh/ton of cement.

2. Hainan Huaren Cement

In June 2022, the roller press was upgraded, increasing hourly output from 150-160 tons to 180-200 tons, with energy consumption reduced to about 23 kWh/ton.

3. Guizhou Southwest

Through the upgrade, output has risen to 180-190 tons/hour, and energy consumption decreased from 32 kWh/ton to 25 kWh/ton.

4. Jiangxi Sanqing Cement Co., Ltd.

After the modification, the output increased to 270-280 tons/hour, with stable operation and nitrogen bag temperatures maintained at 40-60°C.

 

VII.Benefits of Roller Press Technology Upgrade and Modification

  • The stability of the roller press has improved, with virtually no side leakage. There are three methods for adjusting roller skew: first, four-directional feed adjustment; second, hydraulic system adjustments; and third, separate pressure adjustments for left and right. Control is stable, with minimal occurrences of material collapse and roller skew.
  • The hydraulic system of the roller press is flexibly adjustable and controllable. The fluctuation of the roller gap has changed from slow retraction and fast advance to fast retraction and slow advance, increasing pressing efficiency. The fine powder content at the roller press outlet has increased by 3-7%, the specific surface area of the input material has improved, and hourly output has increased by 10-20%.
  • A constant power control method is used, with operational power maintained at 85±5% of the rated power. The efficiency of the roller press has two requirements: first, high operational power; second, high first-pass yield. By improving the efficiency of the roller press and reducing mill power consumption, the overall energy consumption has been lowered by 2-5 kWh/ton.

 

If you have needs regarding the modification and upgrading of roller press systems, please feel free to contact us at Darko. We will provide you with professional solutions and support.

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How To Choose The Right Conveyor System?

In industrial production, selecting the right conveyor system is crucial. Each type of conveyor system has its advantages and disadvantages, suiting various materials and process requirements. This article will compare chain conveyors, air slide conveyors, and belt conveyors to help you make informed choices in powder conveying.

 

1. Chain Conveyor: Efficient Powder Handling

1.1 What is a Chain Conveyor?

The Chain Conveyor (model FU) is a new type of conveyor system designed to replace traditional screw conveyors. Its design overcomes many shortcomings of screw conveyors, particularly in sealing and wear resistance.

 

1.2 How Does a Chain Conveyor Work?

The FU chain conveyor drags materials using a continuous chain within a wide and high trough. The friction between materials pushes them forward, ensuring efficient transportation. This conveying principle is more advanced than that of screw conveyors and better suits modern production needs.

 

1.3 Advantages of Chain Conveyors

The rise of large-scale new dry cement creates new demands for powder conveying equipment. The FU chain conveyor can handle transportation needs from dozens to thousands of tons. However, when the transportation distance exceeds thirty or forty meters, power consumption and wear on components increase, making the FU chain conveyor seem less effective as a conveyor system. If you have concerns or needs regarding large-scale production, please contact us for the best solutions.

 

A blue air slide conveyor is placed on the factory floor, demonstrating advanced industrial technology

2.Air Slide Conveyor: An Efficient and Convenient Solution

2.1 What is an Air Slide Conveyor?

An air slide conveyor is used to transport easily fluidized powder materials (such as cement and fly ash). It utilizes airflow to convey granular materials and has three types: suction, pressure, and mixed flow.

 

2.2 How Does an Air Slide Conveyor Work?

The air slide conveyor uses the kinetic energy of airflow to make granular materials float and transport along the pipeline. When a high-pressure fan injects air into the permeable layer, materials are fluidized, reducing internal friction and enhancing flowability.

 

2.3 Applications of Air Slide Conveyors

Due to its low energy consumption and high efficiency, the air slide conveyor has become a cost-effective choice in the powder conveying field. It is widely used for transporting easily fluidized powder materials like cement and fly ash. However, installation requires a specific incline angle and must ensure that material moisture and particle size are within appropriate ranges.

 

This is a belt conveyor with red and black conveyor rollers, suitable for the transportation and handling of various materials.

3.Belt Conveyor: Versatile Bulk Transport

3.1 What is a Belt Conveyor?

A belt conveyor is ideal for bulk and granular materials. Its simple design and stable structure keep operational resistance low. The rolling friction between the belt and idlers reduces energy consumption and equipment wear.For an example of a successful implementation, see the Inner Mongolia Meifang Energy Co., Ltd DTII Belt Conveyor Project. 

 

3.2 How Does a Belt Conveyor Work?

A belt conveyor transports materials continuously by using the belt and idlers together. It works efficiently for large volumes, long distances, and directional changes, making it widely applicable.

 

3.3Advantages and Disadvantages of Belt Conveyors

Belt conveyors excel in conveying powder materials. However, they can have challenges, such as sealing issues and high labor intensity for cleaning accumulated materials. These factors make many companies cautious when selecting them. In situations with high volume and long distances, belt conveyors are reasonable choices, but environmental pollution is a concern. If you face these challenges, the Darko team is ready to help.

 

A large Air Chain Conveyor is placed inside the factory waiting to be shipped.

4.Comparing the Three Major Conveying Equipment

Air slide conveyors, FU chain conveyors, and belt conveyors are the three "gems" in the powder conveying field. Air slide conveyors are preferred due to their low investment and operating costs, especially when material moisture and particle size are suitable. The chain conveyor is suitable for smaller volumes and shorter distances, though it has higher energy consumption. In applications requiring high volume and long distances, belt conveyors are indispensable, but concerns regarding sealing and environmental impact must be addressed.

 

5.A New Solution: Air Chain Conveyor

Recently, Darko launched the air chain conveyor, which fills the gaps left by traditional conveying equipment. This new design combines the benefits of chain conveyors and air slide conveyors. It adds an air chamber and permeable layer at the bottom. High-pressure air fluidizes materials and reduces internal friction, allowing for high volume and long-distance conveying.

The enclosed design of the air chain conveyor prevents material spillage, solving the problems traditional equipment often faces during operation. As a result, many companies are now choosing this solution. 

 

6.How to Find the Perfect Conveyor System for Your Company’s Needs?

Do you need assistance in using conveying systems to transport bulk materials such as cement, asphalt, and grains? We design, manufacture, and install various types of conveying systems to meet your company’s needs. If you have any questions, please contact Darko.We look forward to providing you with professional services and support.We can provide customized solutions based on your company's requirements.

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バッグ式集塵機設置の主なヒント

When you install bag dust collectors, keep a few key points in mind. This will help ensure efficient operation and easy maintenance. Ultimately, proper installation improves air quality and boosts productivity in industrial settings.

 

1. Layout of the Dust Collection System

The layout of your 集塵システム is crucial. Therefore, follow these principles for the best results:

 

  • Proximity of Dust Sources: First, combine dust sources into one system if they are close together and operate simultaneously. This approach reduces ducting and enhances efficiency.

 

  • Different Types of Dust: Additionally, if dust sources produce different types of dust but operate at the same time, create a single system if mixed recovery is possible. This simplification benefits overall operations.

 

  • Temperature and Humidity Variations: Moreover, install separate systems for dust-laden gases with varying temperatures and humidity. This can prevent condensation in the ducts, which might lead to operational issues.

 

LCDM bag dust collector can effectively solve the problem of filtering dust during pulse spraying

When many dust sources exist, set up the dust collection system in concentrated zones. Each system should connect to a limited number of exhaust points. If you cannot achieve hydraulic balance through adjustments, consider installing balancing valves on branches with lower resistance. Furthermore, place these valves on vertical ducts to enhance performance.Talk to us if you are dealing with these challenges.

 

Calculate the exhaust volume based on the maximum simultaneous exhaust volume and the leakage volume from intermittent points. Ensure each intermittent point has valves linked to the process equipment. Additionally, maintain leakage volume at 15% to 20% of normal exhaust volume when the valves are closed.

 

Note: When designing multiple exhaust cabinets as one system, determine the system's airflow based on the total airflow of the cabinets used at the same time. Install a valve for airflow regulation at each exhaust cabinet's outlet. Also, ensure that the fan has variable frequency drive capabilities.

 

2. Types of Dust Collection Systems

Bag dust collectors can be classified into three types based on production processes, equipment layout, and exhaust volume:

 

  • Local Dust Collection: For example, install bag dust collectors directly near production equipment. This setup captures and recovers dust on-site. It requires minimal or short ducting, making it efficient.

 

  • Dispersed Dust Collection System: In contrast, when exhaust points in a workshop are spread out, combine appropriate exhaust points based on the nature of the conveyed gases. Therefore, position the industrial dust collectors and fans as close as possible to the dust-generating equipment. This approach leads to shorter ducts and easier pressure balance.

 

  • Centralized Dust Collection System: This system is suitable for workshops with concentrated dust sources. In this case, centralize all exhaust points or arrange several dust extraction systems together. Centralized systems simplify dust handling and maintenance. However, they often require longer and more complex ducting, which can be a drawback.

 

Application in Cement Plants

In cement plants, bag dust collectors play a vital role in several areas:

 

  • Raw Material Handling: They capture dust generated during the processing and transportation of raw materials like limestone and clay.

 

  • Milling Process: During the grinding of cement clinker and other materials, these collectors effectively manage the fine dust produced.

 

  • Mixing and Packaging: Bag dust collectors control dust emissions during mixing and packaging, ensuring a clean environment and high product quality.

 

  • Kiln Emissions: They help in purifying exhaust gases from the kiln, reducing air pollution and adhering to environmental regulations.

 

3. Layout Guidelines for Dust Collectors

When laying out your bag dust collectors, follow these principles:

 

  • First, position the dust collector above equipment like belt conveyors and hoppers if you can integrate the collected dust into the production process. This improves workflow significantly.

 

  • Alternatively, if the collected dust cannot easily integrate, place the dust collector in a suitable location with a dust storage bin. This ensures easy access for maintenance.

 

  • Additionally, locate dust collectors in the negative pressure section of the system. If they are in a positive pressure section, use exhaust fans to manage airflow effectively.

 

  • Ensure the pressure loss at each exhaust point does not exceed 10%. If you cannot achieve this through adjustments, consider installing airflow regulation devices to maintain efficiency.

 

  • Finally, for wet gas purification equipment at risk of freezing, implement anti-freezing measures. In colder regions, install wet gas purification equipment indoors.

 

Note: Position flue gas dust collectors outdoors to ensure proper operation.

 

Make sure that the dust discharge pipes of dry dust collectors and the wastewater discharge pipes of wet dust collectors have measures to prevent air leakage. This helps maintain efficiency and safety.

 

Allowable deviations and inspection methods for dust collector installation

Item No.ProjectAllowed Deviation (mm)Inspection Method
1Horizontal Displacement≤10Theodolite or cable and ruler inspection
2Elevation±10Level, straight line and ruler inspection
3Verticality≤2 per meterHanging wire and ruler inspection
4Total Deviation≤10 

4. Installation Requirements for Bag Dust Collectors

To install your bag dust collectors effectively, follow these requirements:

 

  • Confirm that the installation position is correct and that the unit is securely fixed. Allowable deviations should meet relevant standards for safety and performance.

 

  • Furthermore, ensure that moving or rotating parts operate flexibly and reliably. This step is essential for long-term reliability.

 

  • The installation of ash discharge valves, unloading valves, and sludge discharge valves should be tight for easy operation and maintenance. This facilitates easy access for cleaning and upkeep.

 

 

For the on-site assembly of bag dust collectors, meet these requirements:

 

  • Seal the outer shell properly. Additionally, ensure the filter bag interfaces are secure to prevent dust leakage.

 

  • For compartmentalized reverse-blowing bag dust collectors, install the filter bags straight. Maintain the tension on each filter bag at 30N/m ± 5N/m to ensure optimal performance.

 

  • For mechanical rotary flat bag dust collectors, ensure the rotating arms operate smoothly. The top cover of the clean air chamber should be well-sealed.

 

  • Finally, for pulse bag dust collectors, align the blowing nozzle with the center of the venturi tube. Allow a deviation of no more than 2mm.

 

At Darko, we provide high-quality bag dust collectors and dust collection systems tailored to your industrial needs. Our expertise ensures optimal performance, efficiency, and compliance with environmental standards. We are dedicated to helping you maintain a clean and safe working environment.

パイプとはしごが目立つ大型の工業用ビル。効率的なろ過を行うパルスジェット・バグフィルターを装備。
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サイクロン集塵機の効果的な使い方とは？

Cyclone dust collectors  (also referred to as a cyclone separator or simply a cyclone) are essential in various industrial applications for controlling air quality and minimizing dust emissions. The efficiency of these cyclonic systems hinges on the precise dimensions and relationships of their components.

In this blog, we’ll explore the critical factors that influence the performance of cyclone dust collectors, along with best practices for installation and usage.

The actual application scenario of the whirlwind dust collector is displayed, and its industrial characteristics are displayed

WHAT ARE THE ADVANTAGES AND DISADVANTAGES OF CYCLONE DUST COLLECTORS? 

Advantages

1. Dry Cleaning Method: The dry cleaning method facilitates the centralized treatment and recycling of dust.

2. Corrosive Dust Handling: Cyclone can be used to treat corrosive dust gas.

3. Compact Design: The cyclone separator is small and occupies less space, therefore making it easy to install. Additionally, it has a simple structure and is relatively inexpensive.

4. User-Friendly: The cyclone structure is not complex, making it easy to use.

5. High-Temperature Gas Purification: Cyclone can purify high-temperature dusty gases. The cyclone dust collector made of carbon steel can handle gas temperatures up to 100°C, while those with refractory materials can process gases at 500°C.

Disadvantages

1. Limited Handling Capacity: Due to the small handling capacity of a single cyclone dust collection unit, multiple cyclone collection units need to be connected in parallel for larger volumes.

2. Ineffective on Fine Dust: A cyclone separator is not suitable for treating dust particles smaller than 5μm. For light dust particles and high filtration efficiency, baghouse filters are the preferred choice.

3. Not Suitable for Sticky Dust:The cyclones are ineffective in purifying sticky dust particles.

WHAT ARE THE FACTORS AFFECTING THE EFFICIENCY OF A CYCLONE?

1. Inlet Size

The inlet is a crucial component of a cyclone dust collector, significantly impacting dust removal efficiency. A smaller inlet area increases airflow velocity, which enhances dust separation from other particles.

 

2. Diameter and Height of the Cyclone Cylinder

 

The diameter and height of the cylindrical body influence the efficiency of the cyclone.With a constant rotational airflow speed, a larger diameter results in reduced centrifugal force on the dust particles. This leads to lower dust removal efficiency and makes it harder for dust to be drawn into the machine. Therefore, the inlet diameter should not be excessively large or too small. A suitable size is essential to avoid clogging by larger dust particles.

 

3.Diameter and Depth of the Exhaust Pipe

 

The diameter and depth of the exhaust pipe also affect cyclone dust removal efficiency. A smaller diameter in the exhaust pipe restricts airflow, making it more difficult for dust to exit. To improve efficiency, it's important to increase the exhaust velocity and the pipe diameter.

HOW DO YOU CHOOSE A CYCLONE SEPARATOR?

1.Matching Purification Capacity

The actual amount of dust-laden gas to be processed should match the capacity of the cyclone dust collector. Therefore, when you select the diameter of the cyclone dust collector, keep it as small as possible. If you require a larger airflow, then you can use several smaller diameter cyclone dust collectors in parallel.

2.Inlet Airspeed

The inlet airflow velocity should be maintained between 18 and 23 m/s. If the velocity is too low, dust removal efficiency will decrease. On the other hand, if the velocity is too high, resistance loss will increase. And power consumption will also rise, resulting in little improvement in dust removal efficiency.

3. Low Resistance Loss

You should select a cyclone dust collector with low resistance loss. Additionally, it should have low power consumption. Finally, it should feature a simple structure for easy maintenance.

4. Minimum Dust Particle Capture

The cyclone dust collector should capture the smallest dust particle size. This size should be slightly smaller than the particle size in the gas being processed.

5. High-Temperature Dust-Laden Gas

When you deal with high-temperature dust-laden gas, you should apply insulation. This prevents moisture from condensing inside the collector. If the dust does not absorb moisture and the dew point is between 30°C and 50°C, you should set the collector temperature at least 30°C higher. If the dust is hygroscopic (such as cement, gypsum, or alkaline dust) and the dew point is between 20°C and 50°C, you should maintain the collector temperature 40°C to 50°C above the dew point.

6. Sealed Structure

You should ensure that the cyclone dust collector has a well-sealed structure to prevent any air leakage, especially during negative pressure operations. Additionally, you should emphasize the reliability of the discharge lock device.

7. Explosion-Proof Measures

 For flammable and explosive dust (such as coal dust), explosion-proof measures should be in place. A common practice is to install a safety explosion-proof valve in the inlet pipeline.

8. Dust Concentration Limits

When the dust is less viscous, you can relate the maximum allowable mass concentration of dust to the diameter of the cyclone. Specifically, a larger diameter allows for a higher allowable mass concentration.

WHAT ARE THE INSTALLATION POINTS? 

 

1.Ensure Uniform Airflow Distribution

 

When combining multiple cyclone dust collectors, it is essential to maintain uniform airflow to prevent short-circuiting. The inlet, hopper, and outlet zones must be properly sealed to avoid air leaks.

 

2.Material Selection

 

Depending on the operational conditions, cyclone dust collectors can be constructed from various materials, including steel, organic plastics, and ceramics. Selecting the right material is crucial for ensuring durability and resistance to wear and tear.

 

3.Positioning in Series

 

When connecting cyclone dust collectors in series, they should be arranged based on their performance. High-efficiency collectors should be placed first to capture the majority of the dust before it reaches lower-performing units.

HOW DO YOU MAINTAIN YOUR CYCLONE SEPARATOR?

I. Stable Operating Parameters

The operating parameters of a cyclone dust collector mainly include the inlet airflow velocity, the temperature of the gas being processed, and the inlet mass concentration of dust-laden gas.

♦Inlet Airflow Velocity

For a cyclone dust collector of fixed dimensions, increasing the inlet airflow velocity improves the gas handling capacity. It also effectively enhances separation efficiency. However, this increase also raises the pressure drop. Once the inlet airflow velocity reaches a certain value, the separation efficiency may decline. Additionally, wear may increase, and the lifespan of the cyclone dust collector may shorten. Therefore, you should maintain the inlet airflow velocity in the range of 18 to 23 m/s.

♦Temperature of the Processed Gas

As gas temperature increases, its viscosity rises, which increases the centripetal force acting on dust particles, leading to a decrease in separation efficiency. Therefore, cyclone dust collectors operating under high-temperature conditions should have a larger inlet airflow velocity and a smaller cross-sectional flow rate.

♦Inlet Mass Concentration of Dust-Laden Gas

A higher concentration of larger dust particles significantly carries smaller dust particles, which improves separation efficiency.

 

II. Preventing Air Leakage

 

Air leakage in a cyclone dust collector can severely impact dust removal efficiency. For instance, experts estimate that a 1% air leak at the lower cone or the discharge valve will decrease dust removal efficiency by 5%. Moreover, if a 5% leak occurs, the efficiency will drop by 30%. You can find air leakage in three areas. These areas are at the inlet and outlet flanges, in the body of the cyclone dust collector, and at the discharge mechanism.

 

The causes of air leakage include:

 

Flange Leakage: This is mainly caused by loose bolts, uneven gasket thickness, or irregular flange surfaces.

 

Body Leakage: The primary reason for leakage in the dust collector body is wear, particularly in the lower cone. Experience shows that when the mass concentration of dust-laden gas exceeds 10 g/m³, a 3 mm thick steel plate can wear out in less than 100 days.

 

Discharge Mechanism Leakage: This is mainly due to poor sealing in mechanical automatic discharge valves (e.g., weight-operated valves).

 

III. Preventing Wear in Key Areas

 

Factors affecting wear in critical areas include load, airflow velocity, and dust particle characteristics. The wear-prone areas include the casing, cone, and discharge outlet. Technical measures to prevent wear include:

 

Preventing Discharge Outlet Blockage: This mainly involves selecting high-quality discharge valves and regularly adjusting and maintaining them.

 

Preventing Excessive Gas Backflow into the Discharge Outlet: The discharge valves should be tightly sealed and properly weighted.

 

Regular Inspections: Frequent checks for air leaks due to wear should be conducted to take timely corrective measures.

 

Using Replaceable Wear Plates: In high-impact areas, install replaceable wear plates or increase the wear-resistant layer.

 

Minimizing Welds and Joints: Reduce the number of welds and joints; existing welds should be ground smooth, and flanges should have matching inner diameters and maintain good alignment.

 

Maintaining Airflow Velocities: The tangential velocity of airflow at the cyclone dust collector wall and the inlet airflow velocity should be kept within the critical range.

 

IV. Avoiding Dust Blockage and Buildup

 

Blockages and dust buildup in cyclone dust collectors mainly occur near the discharge outlet and in the intake and exhaust pipelines.

 

Discharge Outlet Blockage and Prevention Measures: Blockages at the discharge outlet are typically caused by two factors:

 

  • large materials or debris (such as shavings, wood chips, plastic bags, shredded paper, rags, etc.) getting stuck at the discharge outlet, leading to dust accumulation around them.
  • excessive dust accumulation in the hopper that has not been discharged in time. Preventive measures include adding a mesh at the intake and creating access holes above the discharge outlet (with covers and gaskets sealed with adhesive).

 

Intake and Exhaust Blockage and Prevention Measures: Improper design often causes blockages at the intake and exhaust ports. Rough right angles or slanted angles at the ports can lead to ash adhesion and buildup. This buildup eventually causes blockages.

CONCLUSION

Cyclone dust collectors are a vital component of effective dust management in industrial settings. By understanding the key design elements, adhering to installation best practices, and implementing innovations from Darko, operators can significantly enhance performance and efficiency. Regular maintenance and attention to detail will ensure that these systems operate at their best, providing a cleaner and safer working environment.

If you have any questions or would like to learn more about cyclone dust collectors and their applications, feel free to reach out.

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Transforming Cement Production with Darko’s Ceramic Damper

01 Issues with Conventional Three-Way Dampers

Darko makes high-performance three-way dampers. They focus on "damper craftsmanship" to improve product quality. Many cement companies face short service lives for their dampers, especially at the kiln inlet. Often, these dampers last less than a year.

Traditional three-way dampers use heat-resistant steel and refractory materials. However, they have several problems:

 

  • Wear-resistant refractory materials do not have enough surface strength for high temperatures.
  • The kiln inlet can reach 1400°C. Common refractory materials cannot handle this heat, leading to weak structures.
  • Metal materials expand with heat, causing the damper to crack or jam.
  • It is hard to control the quality of refractory materials, resulting in inconsistent products.

 

The various damage forms of traditional three-way dampers made of heat-resistant steel and refractory material are shown in the figure below.

Series of four images depicting the process of concrete repair, showcasing damage types in heat-resistant steel dampers.

02 Features of Darko Dampers

Darko's silicon carbide ceramic three-way damper solves these issues. It features:

 

  • Innovative Design: It focuses on modern three-way damper design.
  • Prefabricated Delivery: Customers can install the product right away, saving time and costs.
  • High-performance Materials: It uses hard silicon carbide and alumina, which resist wear and corrosion.
  • Reduced Metal Usage: The main material is ceramic, which lowers metal use and reduces cracking risks.
  • Strict Quality Control: The dampers are prefabricated in a factory to ensure quality and reduce breakage risks.

 

03 Usage of Darko Dampers Near the Kiln Outlet

In June 2018, a cement plant in Henan installed Darko's three-way damper in a new dry-process rotary kiln with a capacity of 5000 T/D. After five months, inspections showed no cracks or wear. The plant was very satisfied.

In 2020, during maintenance, the Darko damper was still in excellent condition. It showed no signs of wear or breakage, greatly increasing its service life.

04 Usage of Darko Dampers Near the Kiln Inlet

Many cement plants place three-way dampers near the kiln inlet for precise control. However, high temperatures and airflow can deform traditional dampers. Darko's ceramic dampers can withstand temperatures up to 1300°C while keeping their strength. This ensures they perform well in high-temperature environments.

Currently, Darko dampers are used in several cement plants. They can last up to one year without frequent maintenance, earning high praise from customers.

05 Summary of Darko Damper Usage

Darko dampers near the kiln outlet can last up to two years. In contrast, traditional dampers last only six months. This significantly improves performance. Darko dampers maintain their integrity with minimal wear, which reduces maintenance costs and downtime.

06 Value Analysis of Darko Dampers

The direct benefits include a long lifespan and high cost-effectiveness. Darko dampers last three to four times longer than traditional ones, reducing replacement frequency and safety risks. Prefabricated delivery and easy installation also lower maintenance costs.

The indirect benefits include better cement quality and lower coal consumption. For a 5000 T/D kiln, Darko dampers help stabilize the production of high-quality cement clinker. This value far exceeds the procurement costs. Additionally, Darko's products support better management and efficiency in the cement industry.

Darko's prefabricated silicon carbide ceramic three-way damper has a long lifespan and reliable performance. It meets the current needs of the cement industry. This damper provides significant benefits for users.

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セメントミルの鋼球の交換方法？

Cement mills are key equipment in cement plants, primarily responsible for grinding cement raw materials. Steel balls inside the cement mill crush these raw materials to the required fineness. The efficiency, yield, and energy consumption of cement mills depend on the characteristics of the internal steel balls. Additionally, the operational status of the cement mill and the grinding efficiency directly affect the final quality of the cement.

 

In the cement production process, the wear of steel balls directly impacts the efficiency and quality of cement mills. Regularly replacing and supplementing these steel balls is crucial for maintaining efficient and stable operation in cement manufacturing.

 

Steel balls, also known as grinding media, are the primary raw material for achieving grinding in cement mills. The size, quantity, and proportion of steel balls during the initial loading are critically important. Any improper addition in these aspects can directly affect the grinding efficiency of the cement mill. During the grinding process, steel balls experience high-intensity wear, leading to issues such as breakage and loss of roundness, which can reduce grinding efficiency. Therefore, ensuring accurate initial ball loading is essential. It's also important to assess the wear of steel balls in the cement mill for timely supplementation, enhancing the production capacity of cement plants.

工場内のセメントボールミルは、巨大な設備と整然とした周辺環境を持ち、工業生産の高度な技術を示している。

Steps for Replacing Steel Balls in Cement Mills

1. Preparation

  • Assess the Current Situation: Regularly check the internal steel balls of the cement mill. Record the degree of wear and the diameter.

  • Develop a Supplementation Plan: Create a detailed plan based on the wear situation and production needs. Include the supplementation cycle, required specifications, and quantities of steel balls.

  • Acquire Appropriate Steel Balls: Ensure the purchased steel balls meet quality standards. This will satisfy the production needs of different cement mills.

 

2. Arrange for Downtime

  • Notify Relevant Personnel: Inform operators and maintenance staff in advance. This ensures all relevant personnel are aware of the downtime arrangements.

  • Choose Downtime: Schedule the replacement during low production periods in the cement plant. This minimizes the impact on output.

 

3.Implementation of Replacement

  • Clean After Shutdown: After shutting down the cement mill, clean the interior. Use suction equipment to remove residual steel balls and dust.

  • Remove Old Steel Balls: Remove the old steel balls from the cement mill. You can do this manually or with mechanical equipment. Take care to avoid injury to personnel and damage to equipment.

  • Load New Steel Balls: Gradually load new steel balls into the cement mill based on the preliminary assessment results. Follow the predetermined proportions.

 

4. Operation and Inspection

  • Start the Mill: After loading the new steel balls, restart the cement mill. Monitor the sounds and vibrations to ensure normal operation.

  • Record Performance Data: After a period of operation, record key parameters. This helps evaluate the performance of the new steel balls.

 

5. Evaluation and Optimization

  • Effectiveness Evaluation: Compare production data before and after the replacement. Analyze the impact on the efficiency, quality, and energy consumption of the cement mill.

  • Optimize Supplementation Plan: Adjust the supplementation cycle and specifications based on the evaluation results. This ensures the production efficiency of the cement plant.

A pile of large steel balls, neatly stacked, with a smooth surface, reflecting the surrounding light and showing the texture of metal.

Common Methods for Supplementing Steel Balls

1. Simple Supplementation Method

This method involves regularly supplementing steel balls in cement mills. Even if only one type of larger ball is added, the reasons for wear will cause the balls added later to form a natural size ratio sequentially.

 

Advantages: Simple and easy to implement, suitable for experienced operators.

 

Disadvantages: Lacks specificity, may not match the properties of the materials being milled, leading to lower grinding efficiency and higher steel consumption.

 

2. Reasonable Balancing Supplementation Method

This method is more targeted and includes the following steps:

 

Material Screening: Screen the new feed and return sand for the cement mill. Calculate the particle size composition of the material to be ground. Group the material by size to determine the required steel ball sizes.

 

Laboratory Testing: Conduct grinding tests with the material to be ground. This helps determine the appropriate ball size formula for the specific ore.

 

Optimize Ball Load: Use the particle size composition that yields good grinding results. Base the supplementation calculations on this composition to achieve the ideal ball load in the cement mill.

 

3. Precise Loading and Supplementation Method

This method is more detailed and includes the following steps:

 

Mechanical Research: Conduct research on the anti-crushing performance of the material to be ground in the cement mill and measure its uniaxial compressive strength.

 

Material Screening: Screen the material to determine its particle size composition. Group the material accordingly.

 

Calculate Ball Size: Use semi-theoretical formulas to calculate the required ball size accurately.

 

Statistical Mechanics Guidance: Use the relationship between crushing probability and steel ball yield to guide the ball matching process.

 

Initial Installation Verification: Validate the effectiveness of the initial installation plan through testing.

 

Supplementation Calculation: Determine the quantity of balls to be added. Use wear calculation methods or graphical methods for this purpose.

 

Safety Precautions

Wear Protective Gear: Ensure all personnel wear appropriate protective gear during replacement in the cement mill.

 

Site Management: Set up warning signs and restrict access to the work area for non-participating personnel.

 

By following these steps and methods to replace and supplement steel balls in cement mills, you can ensure optimal operation for the cement plant. Accurate calculations of the quantities and ratios of steel balls will help maintain the effective operation of the cement mill and improve production capacity.

 

If you are interested in cement mills or other related products, explore the solutions and services offered by Darko. For more information, please feel free to contact us.

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パルスジェットバッグフィルター工業用ダストコントロールのための効率的なソリューション

The pulse jet bag filter is a highly efficient dust collection device, boasting a dust removal efficiency exceeding 99%. This equipment effectively captures fine particles, controlling the dust concentration in emissions to below 10 mg/m³, ensuring clean air.

 

The bag dust collector is very adaptable. It can handle airflow rates from tens of thousands to hundreds of thousands of cubic meters per hour. This filter is widely used in high-pollution industries. For example, it is essential in steel, cement, chemicals, and power generation. Furthermore, it acts as a material collector in processes such as cement production, carbon black manufacturing, and feed processing.

Beneath a bright blue sky, a row of Pulse Jet Bag Filters stands outside the factory. Their sturdy metal structures stand out, highlighting their essential role in air purification.

Structure and Working Principle

The pulse jet bag filter consists of several key components:

  • Cleaning system
  • Sealed dust chamber
  • Main frame
  • Dust hopper
  • Electrical control system for operation

 

Role of the Dust Collector Filter Bag

In the operation of the pulse jet bag filter, dusty gas flows through the dust collector filter bag. The gaps between the filter fibers trap particles larger than the gap diameter. Dust sticks to the filter surface during this process. This method is called screening.

 

Initially, new filter bags have larger gaps between the fibers. This results in less effective dust removal. After some time, a significant layer of dust builds up on the bag surface. This enhances the screening effect. After the dust cleaning process, some residual dust remains on the surface and inside the filter bag. This allows the filter to maintain good dust removal efficiency. Materials like needle-punched felt or plush filter fabric create a dense, porous layer. This optimizes the screening effect without relying only on the dust layer.

 

Dust Cleaning Process

The dust cleaning of the filter bags is achieved through compressed air. The cleaning system consists of an air reservoir, blowing pipes, and electromagnetic pulse control valves. Each row of filter bags is equipped with a blowing pipe at the top, aligned with a nozzle that faces the center of the filter bag. Each blowing pipe has a pulse valve connected to the compressed air reservoir.

 

During the dust cleaning process, the electromagnetic valve opens the pulse valve. This allows compressed air to flow through the nozzle toward the filter bag. The air, along with surrounding gas, enters the filter bag. This causes the bag to vibrate and creates reverse airflow from the inside out. As a result, dust is effectively removed from the outer surface of the bag.

 

The pulse jet cleaning method generates the most energy for dust removal. It is a typical external cleaning approach. This method provides strong cleaning power and leaves minimal residual dust within the filter bag fibers. The filter bag is usually made from felt or needle-punched fabric. The pulse jet action causes significant deformation of the filter bag, generating substantial stress. Therefore, the filter material must have high tensile strength. Additionally, the frequent friction between the filter bag and its support frame requires durable materials, such as wear-resistant or woven filter bags.

 

Types of Cleaning Methods

Bag filters can be classified into three types based on their cleaning methods:

1.Mechanical Vibration Type

  • The mechanical vibration type features a simple structure and reliable operation; however, its cleaning effect is relatively weak and prone to damaging the filter bags. Consequently, this cleaning method is becoming less common.

 

2.Reverse Jet Type

  • The reverse jet type can be further divided into chamber reverse jet and nozzle reverse jet.

 

  • Chamber Reverse Jet: This design employs a chamber structure to introduce clean gas from the atmosphere or the dust collection system into different bag chambers for cleaning. However, its cleaning efficiency is low, and the investment cost is relatively high.

 

  • Nozzle Reverse Jet: This type uses a high-pressure fan or compressor to provide reverse airflow, cleaning through a moving nozzle. While it offers strong cleaning capabilities, it is complex and costly, with a high risk of damaging the filter bags.

 

3.Pulse Jet Type

  • The pulse jet type can be categorized based on the pressure of the blowing air into low-pressure (below 0.25 MPa), medium-pressure (0.25 MPa to 0.5 MPa), and high-pressure (above 0.5 MPa) categories. Additionally, it can be divided into rotating pulse jet and inline pulse jet types.

 

  • Rotating Pulse Jet Type: This type features a modular structure, allowing for online or offline cleaning. It has fewer pulse valves and operates reliably, but its complexity requires strict installation and maintenance.

 

  • Inline Pulse Jet Type: Also known as pipe jet pulse filters, these have the blowing pipes fixed within the upper casing of the dust collector. Each pulse valve's blowing pipe typically has multiple nozzles aimed at the filter bags below, allowing for efficient pulse jet cleaning. Its advantages include a simple structure, fewer moving parts, low failure rates, and reliable operation. It allows flexible design of filter bag distribution based on process requirements, with low operating costs. It also utilizes compressed air to ensure sufficient cleaning pressure at the bottom of the filter bags. The overall cost is low, with compartmentalized bag filters enabling online maintenance. However, this type requires a larger number of pulse valves.

 

Factors Affecting Efficiency

Several factors influence the efficiency of the pulse jet bag filter:

  • Dust Characteristics: The size and density of particles affect filtration performance.
  • Filter Material Quality: The quality of the materials directly impacts overall performance.
  • Airflow Velocity: Proper settings can significantly enhance capture rates.
  • Design: A well-planned layout for inlets and outlets helps avoid inefficiencies.
  • Cleaning Method: Effective cleaning is crucial for maintaining filter bag performance.

 

Importance of Maintenance

Regular inspections are essential for achieving optimal operation of the pulse jet bag filter. Maintaining the dust chamber, tightening screws to prevent leaks, and periodically replacing worn seals all contribute to extending the equipment's lifespan.

パイプとはしごが目立つ大型の工業用ビル。効率的なろ過を行うパルスジェット・バグフィルターを装備。
これはセメント工場で使用されるパルスジェットバッグフィルターで、ファンや排気ダクトから離れた場所にメンテナンス用の階段が設置されている。

Why Choose Darko?

At Darko, we are dedicated to manufacturing high-quality cement machinery and equipment. We focus on providing environmentally friendly solutions, including advanced pulse jet bag filters. Our product line includes cement silos, bulk loading systemsそして valves, all designed to enhance your operational efficiency and sustainability.

Conclusion

The pulse jet bag filter is indispensable in industrial environments. It ensures clean air, protects public health, and improves product quality. By choosing the right dust collection equipment, you contribute significantly to clean production and sustainable development.If you have questions about pulse jet bag filter or have questions about our products, please feel free to contact us!

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Key points for choosing cement lump breaker

When choosing a cement lump breaker suitable for a project site, you need to consider multiple factors, including project scale, crushing requirements, equipment performance, economic efficiency, and after-sales service.

Cement lump breaker&cement crusher wear-resistant gears

Here are some specific selection points:

Project Requirements Analysis

Properties of crushed materials:

  • Cement fragments usually have high hardness and density, so you need to choose a crusher that can handle this type of material.
  • If the material contains a lot of steel bars or other metal impurities, you also need to consider the wear resistance and handling capacity of the equipment.

 

Production requirements:

  • Determine the amount of crushed pieces that need to be processed per hour and the required crushing particle size.
  • Choose the appropriate equipment type and scale based on the length of the production cycle.

 

Equipment Performance Evaluation

Crushing capacity:

  • Pay attention to the crushing ratio, processing capacity and particle size distribution of the crushed material.
  • The cement crusher should be able to effectively crush large cement blocks into particles that meet the requirements.

Working stability：

  • Choose a crusher with a stable structure and smooth operation to reduce the impact of vibration and noise on the working environment.

Wear resistance：

  • Considering the hardness of cement fragments, the key components of the crusher (such as blades, lining plates, etc.) should have high wear resistance.

 

Equipment Type Selection

Block cement lump breaker

  • The maximum flow rate of the model can reach 10003/H
  • Applicable to various gasification chutes and storage discharge outlets
  • Designed for material temperatures up to 120 degrees
  • Highly wear-resistant materials are used for crushing claws and grid plates
  • Easy to maintain
  • Integrated speed detection device (optional)
  • When the integrated speed detection device is selected, it is equipped with an electric control box
Close-up view of a cement lump breaker in operation, highlighting its blades and mechanism for crushing clumped cement

Crawler crusher:

  • Suitable for use in large projects such as field quarries and mines.
  • It has the characteristics of simple operation and strong autonomy, and can adapt to complex working environments.

Fixed crusher:

  • Suitable for use in fixed projects such as construction sites.
  • It has the advantages of high output and good stability, and is suitable for large-scale production.

 

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エアスライドコンベアの一般的な故障を解決するには？

Darko Building Materials Machinery is a leading supplier in China, renowned for its high-quality air slide conveyor systems. Our mechanical equipment is finely crafted, quality assured, and available in various specifications. We also offer customization based on your needs and provide comprehensive technical support for our air slide conveyors.

A blue air slide conveyor is placed on the factory floor, demonstrating advanced industrial technology

What is an Air Slide Conveyor?

The air slide conveyor is a type of pneumatic conveying equipment used to transport bulk materials, particularly powders and granules, using air. It efficiently moves dry powdered materials, making it a popular choice in various industries.

 

How It Works

  • Airflow: The conveyor operates by forcing air through a porous surface, causing the material on top to slide along the conveyor.
  • Inclination: It is often installed at a slight incline to facilitate the movement of materials.
  • Low Energy Consumption: The system uses minimal energy compared to traditional belt conveyors, making it an energy-efficient option.

 

Applications

  • Cement and Aggregates: Commonly used in the cement industry for transporting cement, fly ash, and other fine powders.
  • Food Industry: Can be used for transporting flour, sugar, and other dry powders.
    Chemical Industry: Useful for conveying various powdered chemicals.

 

Advantages

  • Gentle Handling: Reduces the risk of damage to delicate materials during transportation.
  • Dust Control: Minimizes dust generation during transport, improving workplace safety.
  • Space-Saving Design: Compact design suitable for limited spaces, making it easy to integrate into existing systems.
Several large metal boxes are stacked together to demonstrate the structure and function of the air slide conveyor

Common Blockage Causes and Solutions for Air Slide Conveyors

1.Damaged Air Permeable Layer

If the air permeable layer of the air slide conveyor is damaged, it can leak ash, causing blockages. Regularly check the air permeable layer and replace it promptly if damaged.

 

2.High Moisture Content

Damp materials or high humidity can block the air permeability layer. Control the moisture content of the conveyed material and frequently clean the filter at the air inlet of the blower.

 

3.Large Particles and Debris

Large particles and debris can slow down material movement and hinder fluidization. Regularly check and adjust the grinding grate gap. Install a slag removal device near the chute feed port to quickly clean up debris.

 

4.Inadequate Exhaust

Failure to exhaust the air conveying chute in time can prevent materials from suspending and fluidizing, leading to blockages. Maintain the exhaust device to ensure it remains intact and unobstructed.

 

5.Improper Slope

Setting the slope of the air conveying chute too low can cause blockages. A larger slope increases the flow rate of materials. For every 1% increase in slope, the flow rate increases by about 20-25%. Adjust the installation slope to maximize conveying performance.

 

6.Dust Accumulation

Dust accumulation in the lower shell of the chute can impede normal air supply, making fluidization difficult and causing blockages. Clean the dust regularly and check for build-up.

 

7.Protecting the Air Permeable Layer

To extend the service life of the breathable layer, add a feed slide at the chute’s feed port. This will prevent direct impact on the breathable layer, reducing wear and aiding material dispersion. Additionally, lay a 1mm thick porous plate on the air permeable layer near the feed inlet to further extend its lifespan.

Shows the different types of conveyor belts and their appearance, including a diagram of an air-slip conveyor belt.

Conclusion

Darko Building Materials Machinery combines R&D, design, manufacturing, and installation. As China’s top supplier of cement machinery and equipment, we customize solutions to meet your specific needs.

We mainly undertake desulfurization and denitrification, dust removal and environmental protection projects, and slag micro powder and powder grinding production lines. Our commitment to quality and innovation ensures that your air slide conveyor operates efficiently and reliably.

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  • +86 15365564889
  • sales@darko-tech.com
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