Candle filter

Cartridge QTY7-190

Filtering Area（(m²)）1-60

Capacity (t/h )2.2-132

Filtering Principle

A candle filter, also called a filter cake layer filter, is composed of a vertical vessel and vertically installed filter units. The filter units consist of a porous petaloid filter cartridge and filter cloth. The real filter media are the filter cloth and filter cake layers that cover the filter cartridge. Filter cloth is fixed on the surface of the filter cartridge.

Main Structure & Working Principle

The candle filter is a fully closed filter system. Its main parts are the material tank, air storage tank, feeding pump, candle filter, pipes, valves, and PLC electric control system.

While filtering, filter material will be sent into the filtering housing by the feed pump first; when it passes through the filter cloth, solid particles will be stopped on the filter cloth. And as the solid particles grow, they will become filter cakes. The holes between solid particles are very small so that they can keep more solid particles, thus getting a clear liquid. Before solid particles become cakes, the filtration will be sent back to the filter material tank and then resended to the vessel. When filter cakes are formed (and reach the required requirement), the PLC will send a signal to stop the circulation, and the clear liquid will pass the filter valve and go to the next process to start the normal filtering process.

After a certain time normal filtering, the cake thickness increases to a high level, the filtering speed slows down, filtering efficiency is decreased, and the filter pressure is >0.5MPa, then the pressure sensor will send a signal to the PLC to stop the feed pump, close the feed valve, and open the forward blowing valve to remove the filtrate in the vessel. When the liquid level in the vessel is lower than the filter cartridge, the PLC will open the drain valve to discharge filtrate, and the pressure will drop swiftly. When the PLC receives a low-pressure signal, it will close the forward blowing valve and open the back blowing valve (compressed air, nitrogen, or steam) to back blow until the cakes fall down. Stop blowing after 30 seconds, and open the cake discharging outlet to discharge cakes. When cakes are discharged, close the cake discharging outlet to finish the filtering cycle. The candle filter will be ready for the next cycle.

Remark

• Max capacity is the reference value based on the water test; the actual value can be different because of liquid viscosity, solid content, and pressure difference.
• The material can be carbon steel, SUS304, and SUS316. According to the nature and temperature of the material filtered, the O-Ring’s material can be customized to meet your needs.