Selection of Filter Press Feed Pump

This article systematically introduces several key considerations in selecting a filter press feed pump.  

In coal washing systems, filter presses can be categorized into clean coal pressure filters and tailings pressure filters based on the slurry they process. The working process consists of three stages: feeding, pressurization (dewatering), and depressurization. The proper operation of the filter press feed pump is directly related to its selection.  

Selecting the right filter press feed pump is crucial. Choosing an appropriate slurry feed pump can significantly improve production efficiency, reduce failure rates, and lower production costs.   

1. Selecting the Right Type of Product

• There are many types of slurry pumps with varying design concepts and methods, resulting in different performance curves. Currently, the performance design of slurry pumps from Shijiazhuang for filter press applications is the most advanced.  
• To best match the working characteristics of the filter press, it is advisable to use dedicated equipment—specifically, a filter press feed pump.  
• This type of pump features a steep performance curve, which aligns well with the operational cycle of the filter press.  
• If other types of pumps are selected, even if the basic parameters meet requirements, issues such as shaft breakage may occur during operation, leading to instability in the coal washing system and shorter lifespans for the pump’s wear parts.  
• During the operation of a wear-resistant slurry pump, deviations from the design flow rate can generate radial forces on the impeller, subjecting the shaft to alternating stresses and causing directional deflection.  

2. Determining the Flow Rate Basis for Selection  

• 1. The parameters of a filter press feed pump in a coal washing system cover a range. Some coal washing plants and design institutes tend to overestimate margins, often following the principle of "bigger is better," which can lead to operational issues with the feed pump later on.  
• 2. In actual selection, full communication with designers is necessary, and the flow rate should be determined based on the filtration area of the configured filter press.  
• 3. It should be noted that the maximum flow rate provided by users (or designers) should not be simply taken as the basis for selection.  
• 4. To match the working characteristics of the filter press, the pump should provide low pressure (head) but high flow rate when initially filling the filter press chamber. During the pressure-holding phase, little to no flow is needed, but higher pressure (head) is required to expel water.  
• 5. If the maximum flow rate is used as the selection basis, the pump’s operating point will shift too far to the right during initial feeding, increasing the risk of cavitation.  
• 6. Worse still, during the pressure-holding phase, the pump will operate in an extremely low-flow region, significantly increasing the risk of shaft breakage. Over time, repeated shaft breakages may occur.