Oil-free Compressed Air Solution for Coal Washing Plant
Oil-free compressed air plays an important role in mining sectors, we would like to share with you an application of dry type oil-free screw air compressor in coal washing plant.
The oil-free air compressor is used with the plate and frame filter press to open the valve and perform core blowing on the filter plate. The specific application is as follows:
Plate and frame filter press is a commonly used solid-liquid separation equipment, which is used to separate the suspension containing solid particles through the filter medium, so as to obtain the separation product of solid and liquid.
1. Filter medium cleaning: During the filtration process, the filter medium (such as filter cloth or filter paper) of the plate and frame filter press may become clogged due to the accumulation of solid particles. Compressed air can be used to clean the filter medium, flushing solid particles from the filter medium by means of air jets or gas pulses to maintain filtration efficiency.
2. Operation control of the filter press: The operation of the plate and frame filter press needs to involve some actions and controls, such as pressure adjustment, plate and frame opening and closing, filter cake falling off, etc. Some of these operations can be done with compressed air. For example, the pressure is controlled by adjusting the input of compressed air, or the opening and closing of the plate and frame is realized by pushing the hydraulic cylinder through compressed air.
Requirements for the quality of compressed air:
1. Dry air: Moisture can adversely affect the operation of a plate and frame filter press, for example by causing contamination or clogging of the filter cloths or plates. Therefore, compressed air should be dried to remove moisture from it, usually an air dryer is required.
2. Clean air: Solid particles, pollutants or grease in the air may damage or contaminate the filter medium of the plate and frame filter press. Therefore, it is necessary to ensure that the compressed air supplied to the plate and frame filter press is clean and does not contain any harmful particles or contaminants, three-grades line filters are required.
The configuration plan sequence for general users is: dry type oil-free compressor + C-grade line filter + air receiver tank + refrigerated air dryer + T-grade line filter+ A-grade line filter, just as below diagram shows:
