The filter press is an important equipment in the coal preparation plant for recovering coal slime, clean coal and other products. Among them, the quick-opening filter press adopts an electromechanical and hydraulic integrated design. It has a relatively high level of mechanization and automation and can realize automatic filter press work. It has pressure maintaining and pressure supplementing functions, which can further reduce the moisture content of the filter cake and improve the recovery quality of the product. During the working process of a quick-opening filter press, its working efficiency is easily affected by many factors such as the characteristics of the feed and the configuration of the filter press, and various mechanical, electrical and hydraulic system failures often occur during operation. , seriously affecting the working performance and operating stability of the filter press, and is not conducive to improving the working efficiency of the filter press. Therefore, in order to improve the use effect of the quick-opening filter press, the main factors and common faults that affect the working efficiency of the filter press are studied, and targeted response strategies are proposed based on the actual situation.
The quick-opening filter press mainly consists of a filter equipment rack, a filtration part, a hydraulic part, an electrical control and a discharge mechanism, etc. The filter equipment rack is the basic construction of the filter press and consists of main beams, oil cylinders, thrust plates, etc. It consists of components; the filtration part is composed of filter plates, filter cloths and matching plates; the electrical control part is mainly composed of a series of electrical components such as electric control cabinets and switches; the unloading mechanism is composed of transmission mechanisms, driving mechanisms, etc.
Its main working principle is: when the filter press performs filtering work, the hydraulic oil enters the hydraulic cylinder through the oil pipe, and the piston rod moves and pushes the head plate forward, accumulating the filter plate in the head plate and tail plate, so that the adjacent filter The plate constitutes a closed filter chamber; the feeding pump is started to drive the material from the feeding hole on the tail plate into the closed filter chamber. The material realizes solid-liquid separation under the action of the feeding pressure, and the filtrate passes through filter cloth, filter plate and other equipment Outflow, the solid material is left in the closed filter chamber. After a certain period of time, the solid material accumulates more and more, and the thickest filter cake is formed. After the filter cake is formed, the filter plates are pulled apart one after another under the action of the air compressor and the oil cylinder, and the filter cake is Under the action of its own weight and the tension of the filter cloth, it falls to the lower transportation equipment, thus completing a cycle of filter pressing operations.
Therefore, when selecting a filter press, on the basis of satisfying the filter press effect, a filter press with a relatively thin filter chamber should be used. Especially when dealing with high-ash and fine-grained coal tailings, a filter press with a smaller filter chamber thickness should be preferred. For the filter press, the working section of the filter chamber should also be increased, and the filter press auxiliary time should be reduced to improve the filter press effect.
The main reason for the breakage of the handle fastening bolt is that during the unloading process, if the handle is skewed, the fastening bolt will be subjected to bending shear force, and the bolt will break after a long period of time. In addition, if the fastening bolt becomes loose If not handled in time, the bolts will still be subject to bending and shearing forces during unloading, causing deformation and fracture of the bolts. The main measures to solve the broken handle bolts on both sides of the filter plate include: strengthening equipment maintenance and maintenance, promptly correcting the handles, promptly tightening loose handle fastening bolts, and promptly replacing deformed and cracked bolts.
There are two main types of filter plates used in filter presses: cast iron filter plates and rubber filter plates. The rubber filter plate has a simple structure and good sealing performance. However, after being used for a period of time, the rubber filter plate is prone to fatigue damage to the rubber layer, causing the filter plate to deform. The required tightening pressure of the cast iron filter plate is 8-10MPa. Since the sealing performance of the cast iron filter plate is slightly poor, if the tightening pressure does not meet the technical specifications, it will easily cause material leakage. When the tightening pressure is too high, it will easily cause the cast iron filter plate to appear. Slightly bent and deformed. To prevent filter plate deformation, the main thing is to ensure that the filter plate material and installation quality comply with the design specifications. The filter plate pressing pressure must meet the filter plate requirements. At the same time, the filter plate should be cleaned in time after the filter press operation is completed to avoid the filter plate being damaged during work. force balance. The tightening pressure of the filter plate needs to meet the installation requirements of the filter plate. If the tightening pressure is too high and there is a problem with the filter plate material, such as sand holes in the cast iron filter plate, excessive pressure may easily cause local deformation of the filter plate and even damage the filter plate. fracture.
Working principle of quick opening filter press
The Fast opening filter press with vibration device is an intermittent filter press equipment. Its production technology involves mechanical, electrical, hydraulic and other processes. It is mainly used for solid-liquid separation of suspensions. It is widely used in coal preparation plants for coal slime water treatment and Recycling of clean coal.The quick-opening filter press mainly consists of a filter equipment rack, a filtration part, a hydraulic part, an electrical control and a discharge mechanism, etc. The filter equipment rack is the basic construction of the filter press and consists of main beams, oil cylinders, thrust plates, etc. It consists of components; the filtration part is composed of filter plates, filter cloths and matching plates; the electrical control part is mainly composed of a series of electrical components such as electric control cabinets and switches; the unloading mechanism is composed of transmission mechanisms, driving mechanisms, etc.
Its main working principle is: when the filter press performs filtering work, the hydraulic oil enters the hydraulic cylinder through the oil pipe, and the piston rod moves and pushes the head plate forward, accumulating the filter plate in the head plate and tail plate, so that the adjacent filter The plate constitutes a closed filter chamber; the feeding pump is started to drive the material from the feeding hole on the tail plate into the closed filter chamber. The material realizes solid-liquid separation under the action of the feeding pressure, and the filtrate passes through filter cloth, filter plate and other equipment Outflow, the solid material is left in the closed filter chamber. After a certain period of time, the solid material accumulates more and more, and the thickest filter cake is formed. After the filter cake is formed, the filter plates are pulled apart one after another under the action of the air compressor and the oil cylinder, and the filter cake is Under the action of its own weight and the tension of the filter cloth, it falls to the lower transportation equipment, thus completing a cycle of filter pressing operations.
Factors affecting the working efficiency of quick-opening filter press
2.1Physical and chemical properties of feed coal slime
Theoretical research and production practice show that when the pressure difference on both sides of the coal slime and the resistance of the filter medium are relatively fixed, the greater the viscosity of the coal slime, the worse the filter press effect. The viscosity of coal slime slurry is not only affected by the concentration of coal slime, but also the particle size, ash content, mineral composition, etc. of coal slime have a direct impact on the viscosity of coal slime. The smaller the particle size, the greater the ash content, and the higher the mineral mud content. , the greater the viscosity of the coal slime slurry. Therefore, when using a filter press to treat coal slime water, the structural composition of the coal slime should be mastered, and the optimal slime concentration ratio should be determined to ensure that the filter press is at the optimal pressure. filter status.2.2Filter press working conditions
The process of press filtering to form a cake refers to the process in which coal slime water fills the filter chamber and the filtrate is discharged. The greater the solid concentration in the coal slime water, the smaller the filtrate will be, and the shorter the time required to press filter to form a cake within a certain range, but considering As the viscosity of the slurry increases relative to the concentration, the solid concentration in the slime water should be reasonably controlled. Different properties of coal slime have higher requirements on feeding pressure, but relatively speaking, the greater the feeding pressure, the better the effect of filtering into cakes and the shorter the time required, especially as the filtering operation proceeds. , the thickness of the filter cake continues to increase, and ensuring a certain feeding pressure is the key to ensuring the filter press effect.2.3Filter chamber thickness and auxiliary time of filter press
Studies have shown that reducing the thickness of the filter chamber can help improve the filter press efficiency and reduce the filter press time. Therefore, theoretically, the thinner the filter chamber of the filter press, the more conducive it is to the filter press operation. Since the filter press is an intermittent operation equipment, in addition to the filter press time, it also has auxiliary operation time. Therefore, reducing the auxiliary time can also correspondingly reduce the cycle operation time of the filter press, which relatively improves the filter press efficiency.Therefore, when selecting a filter press, on the basis of satisfying the filter press effect, a filter press with a relatively thin filter chamber should be used. Especially when dealing with high-ash and fine-grained coal tailings, a filter press with a smaller filter chamber thickness should be preferred. For the filter press, the working section of the filter chamber should also be increased, and the filter press auxiliary time should be reduced to improve the filter press effect.
2.4Filter press configuration
When a coal preparation plant is equipped with filter presses to recover coal slime, multiple filter presses are often used at the same time. In practice, it is believed that multiple filter presses should be prioritized to operate in parallel. This way, on the one hand, the height requirements for the plant are lower, and on the other hand, certain filter presses are used at the same time. When the filter press is shut down or doing other operations, other filter presses will not be affected.Analysis and countermeasures of common faults of filter press
3.1Mechanical part failure
3.1.1 Filter plate failure
Filter plate damage is the most common failure of filter presses. The main forms of filter plate damage include broken filter plate handle bolts, filter plate deformation and filter plate breakage, accounting for 46%, 32% and 22% of filter plate damage statistics respectively.The main reason for the breakage of the handle fastening bolt is that during the unloading process, if the handle is skewed, the fastening bolt will be subjected to bending shear force, and the bolt will break after a long period of time. In addition, if the fastening bolt becomes loose If not handled in time, the bolts will still be subject to bending and shearing forces during unloading, causing deformation and fracture of the bolts. The main measures to solve the broken handle bolts on both sides of the filter plate include: strengthening equipment maintenance and maintenance, promptly correcting the handles, promptly tightening loose handle fastening bolts, and promptly replacing deformed and cracked bolts.
There are two main types of filter plates used in filter presses: cast iron filter plates and rubber filter plates. The rubber filter plate has a simple structure and good sealing performance. However, after being used for a period of time, the rubber filter plate is prone to fatigue damage to the rubber layer, causing the filter plate to deform. The required tightening pressure of the cast iron filter plate is 8-10MPa. Since the sealing performance of the cast iron filter plate is slightly poor, if the tightening pressure does not meet the technical specifications, it will easily cause material leakage. When the tightening pressure is too high, it will easily cause the cast iron filter plate to appear. Slightly bent and deformed. To prevent filter plate deformation, the main thing is to ensure that the filter plate material and installation quality comply with the design specifications. The filter plate pressing pressure must meet the filter plate requirements. At the same time, the filter plate should be cleaned in time after the filter press operation is completed to avoid the filter plate being damaged during work. force balance. The tightening pressure of the filter plate needs to meet the installation requirements of the filter plate. If the tightening pressure is too high and there is a problem with the filter plate material, such as sand holes in the cast iron filter plate, excessive pressure may easily cause local deformation of the filter plate and even damage the filter plate. fracture.
3.1.2 Material leakage from filter plate
In addition to the deformation of the filter plate, material leakage from the filter plate is mostly caused by uneven filter cloth, or the filter cloth is folded or has holes in the filter cloth during the filter press process. When encountering this problem, the filter cloth must be adjusted in time. , clean up debris and replace the holed filter cloth in time.3.2Electrical component failure
Faults in the electrical components of the filter press mainly include faults in the solenoid valves in the pumping station, faults in the electrical contact pressure gauge and other valve solenoid valves. Failures in the solenoid valves in the pumping station will cause the pressure to not tighten or loosen, and will also cause the stop push pin to not push. To judge the failure of the solenoid valve in the pump station, we mainly use manual inspection to see if the coil of the solenoid valve is burned out. If so, the solenoid valve can be replaced. The direct manifestation of the failure of the electric contact pressure gauge is compression timeout or venting timeout. If there is a fault, it can be replaced directly. In addition to the pump station, the filter press is also equipped with various other types of solenoid valves. If the wind control solenoid valve is insensitive or does not move, check whether the solenoid valve has any spots or whether the coil is damaged. If it is damaged, it can be replaced directly. If the solenoid valve starts when it should not start, then there is a connection in the solenoid valve circuit, which can be eliminated.3.3Hydraulic system failure
Hydraulic system faults mainly include insufficient pressure maintenance, insufficient oil pressure, and loud hydraulic system noise. The main reason for insufficient pressure maintenance is that the hydraulic control valve does not work. This can be solved by cleaning the hydraulic control valve and replacing the seal. If insufficient pressure maintenance still occurs, , it can be judged that the internal wear of the hydraulic control valve is serious and the hydraulic control valve needs to be replaced; insufficient oil pressure is mostly caused by a failure of the relief valve. In addition, wear and tear of the oil pump and damage to the seal will also cause insufficient oil pressure. In order to ensure normal oil pressure , check the relief valve, oil pump and seals regularly; air sucked into the cylinder and loose fasteners will cause loud noise in the hydraulic system. To avoid air sucked into the cylinder, first ensure that the sealing performance of the cylinder is good, refuel in time, and when sucking in Deflate the air in time, and reinforce the fasteners regularly.As an important coal slime and clean coal recovery equipment in the coal preparation plant, the quick-opening filter press’s working performance is affected by many factors such as feeding characteristics, working conditions, configuration methods, etc., so it should be carefully selected and used during the selection and use of the filter press. Understand the characteristics of the feed material and the characteristics of the filter press itself to ensure that the filter press can operate at its best. During the operation of the filter press, various faults involving the mechanical, electrical and hydraulic systems are prone to occur. On the basis of mastering the working principle of the filter press, one should understand the underlying causes of the fault and take targeted measures. Only in this way can the filter press be ensured to be in stable operation, thereby ensuring the normal production of the coal preparation plant.
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