Filter cake dewatering problem
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The slurry obtained from the bottom of the sedimentation tank is generally dehydrated into a filter cake using a vacuum filter before being sent out of the factory. What technologies are currently available or potentially capable of replacing this processing step?
A diaphragm filter press can be chosen; it is more efficient than a vacuum filter. If the problem can be solved with a vacuum filter, then it can generally be solved with a filter press as well.
What is the processing capacity of a diaphragm filter press?
Traditional vacuum belt filters have the advantages of continuous operation and a mature processing technology. The drawback is the high water content in the filter cake; even with well-performing equipment, the moisture content can only be reduced to 60%. Alternative options include: 1. Fully automatic diaphragm filter press. Be sure to choose a model that can automatically compress, maintain pressure, flip the plates, clean the filter cloth, and automatically control the feed pump, pressing pump, and pneumatic valves. Since diaphragm pressing is itself a batch-type process with short cycle times, an fully automatic operation mode can reduce the operational workload on site while ensuring optimal pressing results. The downside is that the investment is high, there are many moving parts, and it is estimated that maintenance work will be substantial in the later stages of the equipment’s operation. Additionally, for automatic filter cloth cleaning, the plant layout requires additional height (it is recommended to approach the installation of this feature with caution). Advantages: The moisture content in the filter cake is low, typically 40-50% (depending on the pressing pressure and the properties of the ash). 2. Horizontal centrifugal type. In coal gasification, only imported brands perform well. It operates continuously, has a low installed power capacity, and thus low operating costs. The disadvantages are poor comparability and high price. The moisture content is between that of the diaphragm filter and the vacuum belt filter.