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 dust collection system 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.

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.	Project	Allowed Deviation (mm)	Inspection Method
1	Horizontal Displacement	≤10	Theodolite or cable and ruler inspection
2	Elevation	±10	Level, straight line and ruler inspection
3	Verticality	≤2 per meter	Hanging wire and ruler inspection
4	Total 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.

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How to Effectively Use Cyclone Dust Collectors?

10/07

2024

10/07/2024

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.

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

09/30

2024

09/30/2024

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.

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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How to Replace Steel Balls in Cement Mills？

09/20

2024

09/20/2024

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.

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.

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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Pulse Jet Bag Filter: An Efficient Solution for Industrial Dust Control

09/06

2024

09/06/2024

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.

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.

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, and 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

08/15

2024

08/15/2024

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.

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

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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How to solve common faults of air slide conveyor?

08/06

2024

08/06/2024

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.

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.

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.

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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Inner Mongolia Meifang Energy Co.,Ltd DTII Belt Conveyor Project

07/08

2024

07/08/2024

The DTII Belt Conveyor Project, manufactured by Nantong Darko Building Materials Machinery, showcases robust conveying capacity and an extensive conveying distance. This advanced system features a simple structure that allows for easy maintenance, ensuring operational efficiency and minimal downtime. Moreover, the project seamlessly integrates program control and automatic operation, significantly enhancing overall productivity and reliability in material handling.

The DTII belt conveyor demonstrates its operational capability even in challenging weather conditions, as it traverses snowy areas. This adaptability highlights its durability and effectiveness in a variety of environments.

Project Overview:

Company: Inner Mongolia Meifang Energy Co., Ltd.
Production Capacity: 2×960,000 tons per year
Belt Widths: 1.4m, 1.2m, 0.8m, 0.65m
Total Length: 3,500m

DTII Belt conveyor Principle

The conveyor belts (or wire ropes) are connected into a closed ring, and they are tightened with a tensioning device. Driven by the motor, the friction between the conveyor belts (or wire ropes) and the driving rollers (or driving wheels) makes the conveyor belt move. The belt (or wire rope) runs continuously to achieve the purpose of transporting the cargo from the loading end to the unloading end.

Advantages of our belt conveyor

Large Transmission Flow Rate: Capable of handling substantial volumes of material quickly.
Very Low Energy Requirement: Designed to operate efficiently, reducing energy costs.
Low Investment and Service Costs: Cost-effective design minimizes initial investment and ongoing maintenance expenses.
Stable and Trouble-Free Transportation: Ensures reliable delivery of products without interruptions.
User-Friendly Operation: Easy to operate, making it accessible for all personnel.
Reduced Manpower and Higher Productivity: Streamlined processes lead to improved efficiency and reduced labor costs.
Continuous Operation: Maintains a steady flow of materials, enhancing overall production capabilities.

By implementing the DTII belt conveyor system, Inner Mongolia Meifang Energy Co., Ltd. not only improves its material handling processes but also supports its commitment to operational excellence and sustainability in energy production.

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Hebei Qianbao Special Cement Co., Ltd dust collector project

07/08

2024

07/08/2024

The dust collector project at Hebei Qianbao Special Cement Co., Ltd. features advanced equipment, including PPCS air box pulse dust collectors and HMC single-machine pulse dust collectors. These systems are designed to enhance air quality and meet stringent environmental standards across the cement production process.

At Nantong Darko Building Materials Machinery, we utilize state-of-the-art laser cutting technology for our dust collector panels. This innovative technology not only ensures the smoothness of the panels but also allows for precise processing of panel holes, significantly contributing to the overall efficiency and reliability of the dust collection system.

As a comprehensive high-tech enterprise, Nantong Darko integrates research and development, design, manufacturing, and installation. We possess foreign trade rights, import and export credentials, as well as construction engineering qualifications, enabling us to serve clients on a global scale.

Our team consists of highly skilled designers and technical experts specializing in dust collector manufacturing. We take pride in our professional processing and production capabilities, along with exceptional after-sales service, ensuring our clients can operate with confidence.

Dust Collector Project Background

Hebei Qianbao Special Cement Co., Ltd. operates a white cement production line with a capacity of 1,800 tons per day. The project handles a gas volume of 240,000 m³/h, achieving efficient dust removal while adhering to environmental protection standards. Additionally, the system is designed for easy operation.

Advantages of our dust collectors

High Dust Removal Capability
Our modern dust collectors utilize advanced filtering technologies, including bag filtration, electrostatic dust removal, and wet dust removal. These technologies efficiently capture dust particles of various sizes, achieving a capture efficiency of up to 99.9%. As a result, emissions consistently meet strict environmental standards.
Multi-Stage Filtration System
By implementing a multi-stage filtration system, we further enhance the dust capture rate. This ensures that even fine dust is effectively captured, thereby reducing secondary pollution.

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Huaxin Green Building Materials (Wuxue) Co., Ltd. Dust collector project

07/08

2024

07/08/2024

Huaxin Green Building Materials (Wuxue) Co., Ltd. Dust collector project

Project Background

Huaxin Green Building Materials (Wuxue) Co., Ltd. has launched a mechanical sand project that achieves full production of 30 million tons per year. With a total investment of 3 billion yuan, the construction completed in just 18 months. This project utilizes dry production methods to effectively address solid waste issues.

Technical solution design

Based on our demand analysis, we designed a customized dust collector solution:

High-Efficiency Dust Collectors: We use bag dust collectors with pulse jet technology for dust removal.

Advanced Control Systems: Our solution features automatic systems for remote monitoring and operation.

Multi-Stage Filtration: We implement a multi-stage filtration system to enhance dust removal efficiency.

Quantity: 55 sets

Gas Volume Handled: 52,000 m³/h, 17,580 m³/h, 26,700 m³/h, 33,400 m³/h

Auxiliary Equipment: Rotary or discharge valve, screw conveyor

Equipment manufacturing and installation

After finalizing the equipment design plan, our team quickly began manufacturing. We completed production within the specified timeframe. Next, the installation team arrived on-site. They followed the design drawings and construction plan to implement each step accurately.

Huaxin Green Building Materials (Wuxue) Co., Ltd. has achieved full production of 30 million tons per year mechanical sand project. With a total investment of 3 billion yuan, the construction was completed in just 18 months. The project utilizes dry production methods to address solid waste issues.

Debugging and acceptance

We completed the installation. Then, we thoroughly debugged the dust collector equipment. We conducted multiple tests. These tests confirmed that the equipment operates stably and efficiently under various conditions. The cement plant and the environmental protection department accepted the dust collector equipment.

Project Results

Significantly Reduced Dust Emissions: We put the dust collector equipment into operation. This action significantly reduced dust emissions and exceeded national and local standards.
Improved Production Environment: The air quality in the factory area improved greatly. This improvement enhanced the working conditions for employees.
Lower Operating Costs: Our dust removal system reduces maintenance frequency and costs. This change improves production efficiency.

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Huaxin 10,000-ton line dust collector project

07/08

2024

07/08/2024

Dust collector project

Project Background

The Huaxin 100 million ton production line is an important project. It aims to meet the demand for high-quality building materials. We use advanced production processes and equipment. The project team decided to use efficient dust collector equipment. This choice protects the environment and reduces dust emissions.

The Huaxin clinker production line can produce 10,000 tons per day. It is the world’s largest environmentally friendly cement kiln line.

Project Content

Equipment Selection and Design: We selected durable equipment for the Huaxin 100 million ton line. Our design team customized the solution based on the project site conditions. This customization ensures optimal performance.

Installation and Commissioning: Our technical team followed the design plan during installation. They ensured accurate implementation at every stage. After installation, we conducted thorough commissioning to confirm stable operation under various conditions.

Technical Training and Maintenance: We provided technical training for the operators of the Huaxin 100 million ton line. This training helped them master the operation and maintenance of the dust collector. We also created a maintenance plan for regular inspections to extend the equipment’s service life.

Project Advantages

Efficient Dust Removal: The equipment captures dust effectively; as a result, it significantly reduces emissions and improves air quality.
Environmental Protection: The project ensures that dust emissions meet national and local standards. This compliance helps prevent pollution.
Ease of Operation: The equipment design prioritizes user-friendliness. It reduces operator labor and boosts production efficiency.

Conclusion

Our work on the dust collector project for Huaxin’s 100 million ton production line marks a significant achievement. We are committed to applying and innovating environmental technologies. Our goal is to promote the green development of industrial production.

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How to solve the quality problem of cement silo in cement clinker production line

07/08

2024

07/08/2024

1、Project Overview

The cement silo for a clinker production line began operation in 2007. It features a reinforced concrete circular structure with a height of 61.81 m and an inner diameter of 22.5 m. The silo wall is 380 mm thick and reinforced with non-prestressed steel bars. The concrete strength is designed to be C30.

After the silo started operation, inspections found multiple vertical and circumferential cracks on its outer surface. These cracks appeared mainly between elevations +14.166 m and +50 m.Some cracks exceeded 0.2 mm in width, violating specifications. Inspectors also found hollow areas and peeling concrete on the silo wall. Consequently, the owner required technical reinforcement for the cement silo.

2. Analysis of the cause of the accident

Upon discovering the cracks, the owner commissioned a testing agency to evaluate the silo wall’s concrete strength, reinforcement, and cracks. The tests showed that the concrete strength generally met design requirements. However, the annular reinforcement from +14.166 m to +50.000 m mostly did not meet specifications. The crack widths between +23.5 m and +34.2 m also fell short of requirements.

The inspection revealed that vertical cracks resulted from stress and temperature effects on the wall. Circumferential cracks occurred due to insufficient reinforcement and poor joint connections. The team constructed the raw material homogenization silo using a slipform process. This method created tied and overlapped horizontal reinforcement joints. It did not use welded connections.The protective layer around the reinforcement was too thin. This weakened the bond between the reinforcement and the concrete.

3. Reinforcement treatment（Scheme selection）

We considered two solutions for reinforcing the raw material homogenization silo. One solution involves reinforcing the outer wall with concrete. The other solution applies external prestressing. Below is a comparison of both methods.

3.1.1 Use reinforced concrete to increase the cross-section of the cylinder wall

This method involves adding 200 mm of reinforced concrete to increase the cross-section of the cylinder wall from the foundation ring beam to +50 m. This solution would require reverse mold construction and take about six months to complete. Since the silo operates during this time, the long construction period is a drawback. Additionally, the new structure may not fully integrate with the existing steel bars, reducing material efficiency. The estimated cost for this method is around 2 million yuan, making it less favorable in terms of effectiveness and cost.

3.1.2 External prestressing reinforcement

Cracks mainly arise from inadequate circumferential reinforcement and temperature stress. We can place steel strands along the outer surface in the circumferential direction. Applying external prestressing will help the internal circumferential reinforcement and external strands work together.

Since the silo is currently in use, this method can effectively reinforce the structure and potentially close some cracks. The estimated cost for this project is about 1 million yuan.

Conclusion

Considering the reinforcement effectiveness, cost, and site conditions, we determined that the external prestressing method is the most reasonable and economical solution for this silo.

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CONATCT

1. Layout of the Dust Collection System

2. Types of Dust Collection Systems

Application in Cement Plants

3. Layout Guidelines for Dust Collectors

4. Installation Requirements for Bag Dust Collectors

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

2. Diameter and Height of the Cyclone Cylinder

3.Diameter and Depth of the Exhaust Pipe

HOW DO YOU CHOOSE A CYCLONE SEPARATOR?

1.Matching Purification Capacity

2.Inlet Airspeed

3. Low Resistance Loss

4. Minimum Dust Particle Capture

5. High-Temperature Dust-Laden Gas

6. Sealed Structure

7. Explosion-Proof Measures

8. Dust Concentration Limits

WHAT ARE THE INSTALLATION POINTS?

1.Ensure Uniform Airflow Distribution

2.Material Selection

3.Positioning in Series

HOW DO YOU MAINTAIN YOUR CYCLONE SEPARATOR?

I. Stable Operating Parameters

♦Temperature of the Processed Gas

♦Inlet Mass Concentration of Dust-Laden Gas

III. Preventing Wear in Key Areas

CONCLUSION

01 Issues with Conventional Three-Way Dampers

02 Features of Darko Dampers

03 Usage of Darko Dampers Near the Kiln Outlet

04 Usage of Darko Dampers Near the Kiln Inlet

05 Summary of Darko Damper Usage

06 Value Analysis of Darko Dampers

Steps for Replacing Steel Balls in Cement Mills

1. Preparation

2. Arrange for Downtime

3.Implementation of Replacement

4. Operation and Inspection

5. Evaluation and Optimization

Common Methods for Supplementing Steel Balls

1. Simple Supplementation Method

2. Reasonable Balancing Supplementation Method

3. Precise Loading and Supplementation Method

Safety Precautions

Structure and Working Principle

Role of the Dust Collector Filter Bag

Dust Cleaning Process

Types of Cleaning Methods

1.Mechanical Vibration Type

2.Reverse Jet Type

3.Pulse Jet Type

Factors Affecting Efficiency

Importance of Maintenance

Why Choose Darko?

Conclusion

Project Requirements Analysis

Properties of crushed materials:

Production requirements:

Equipment Performance Evaluation

Crushing capacity:

Working stability：

Wear resistance：

Equipment Type Selection

Block cement lump breaker

Crawler crusher:

Fixed crusher:

What is an Air Slide Conveyor?