O válvula de descarga estrela, also known as the rotary discharge valve, is widely used in industries such as chemicals, coal, metallurgy, and food processing. It is usually installed at the inlet or outlet of other equipment, such as the outlet of bag filters and the inlet of pneumatic conveying systems. The main function of this valve is to ensure that powdered materials flow from the upper end to the lower end under gravity. It also isolates the gas systems above and below, preventing interference.
Structure and Principle of the Star Discharge Valve
The star discharge valve is a key device in the transportation of powdered or fine particulate materials. It acts as a transitional device that effectively isolates the gas phases of two systems. Typically, the star discharge valve is installed vertically, with the valve shaft positioned horizontally, allowing gravity to continuously transport materials from the top to the bottom.
This valve consists of a housing, an impeller rotor, shaft seals, bearings, and a drive motor. During operation, fine powders or particles fall into the impeller slots under gravity. The rotating impeller then sends the materials to the lower collection hopper or pneumatic conveying system. Throughout this process, the impeller maintains gas isolation between the upper and lower sections by fitting closely with the inner wall of the housing.
Analysis of Axial Leakage Causes
Common faults during the operation of the star discharge valve include seal failure, bearing wear, and impeller jamming. Among these, axial leakage is the root cause of these issues. Seal failure typically arises from axial leakage of materials, which in turn leads to bearing wear and impeller jamming.
Causes of Seal Failure
A newly installed star discharge valve usually does not show axial leakage in the early stages of use. However, as usage time increases, leakage gradually worsens. When inspecting the sealing surface of the impeller shaft, noticeable wear marks can be observed. Statistical analysis indicates that the strength and hardness of powder particles significantly affect the valve's lifespan. High-hardness catalytic cracking catalyst powders can easily wear down the sealing surfaces during continuous friction, leading to leakage.
Structural Improvement Solutions
To address the leakage issue of the star discharge valve, the following effective improvement measures can be implemented:
1. Improve the Wear Resistance of the Impeller Rotor Shaft
Enhancing the wear resistance of the impeller rotor shaft surface is essential for extending the equipment's lifespan. Increasing the surface hardness of the shaft, ensuring it exceeds the hardness of the powder material, can effectively reduce wear. This can be achieved by:
- Using high-strength alloy steel materials, such as 2Cr13 or 3Cr13, and applying heat treatment.
- Implementing surface treatments like chrome plating, hard alloy spraying, or laser cladding.
2. Improve the Structure of the Impeller Rotor Shaft
Designing the impeller rotor shaft as a split structure can reduce maintenance costs and time. Using threaded connections allows for quick replacement of the shaft heads when seals fail, minimizing the risk of replacing the entire unit. Ensuring that the thread direction matches the motor's rotation can also prevent failures due to jamming.
After these structural improvements, the star discharge valve has operated for over a year without any axial leakage, significantly extending its lifespan.
Conclusão
Through in-depth analysis of the faults in the star discharge valve, we identified the root causes of axial material leakage and developed effective improvement measures. These not only extend the equipment's lifespan but also reduce maintenance costs. The key measures are:
1.Increase the hardness of the sealing surfaces to enhance wear resistance, significantly extending the equipment's lifespan.
2.Use a split structure for the sealing shafts to lower maintenance costs and reduce repair time.
With these improvements, the performance of the star discharge valve has significantly enhanced, providing more reliable solutions for material transport in relevant industries. For more information about our products or services, please contactar-nos. We look forward to providing you with quality solutions!
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