Horizontal Plate Filters are generally operated in a wide range of applications, mainly the chemical & resin industries, removing and filtrating a high level of impurities. However, this filter can be used for batch or continuous filtration process, it is easy to maintain, it does not contain any moving parts and the filter cartridges can be quickly and easily removed and replaced with a spare part cartridge.
Horizontal Plate Filters are called the workhorse of the chemical Industry. These filters can be used for almost all industrial applications and will perform reliably and provide a clear filtrate.
The Horizontal Plate Filters are multipurpose filtration units and have a long lifetime, which makes them economical.
Below we present 10 things to consider in the installation and start-up of the horizontal filter plate:
- Workplace
The filter is built-in legs with support lugs attached to the shell. The support lugs must be placed and tightened on a solid surface. The foundation has to be calculated concerning the weight of the filter including filter elements and filled with liquid.
- Piping connections
The piping should be connected to the filter free of stress via the flange connections. These should be supported close to the filter and easily connected on to avoid distortion.
When attaching the piping to the filter, is recommended the use of dimensional drawing to assure that you make the right connections.
- Assembling the filter cartridge
The filter cartridge is always inserted or removed from the tank completely assembled.
Assembly and disassembly are performed outside the filter tank.
To remove the filter cartridge from or insert into the filter tank, a hoist and chain with hooks must be used. The hook should engage the lifting handles on the top compression plate of the filter cartridge.
When the cartridge is taken out of the filter vessel, it should be placed onto a wooden platform to avoid damaging the gasket’s surface.
- Closing the filter
The cover gasket has to be placed in the gasket groove of the body flange. This gasket needs to be cut from a roll diagonally. When placing the gasket, the diagonal ends should overlap, and we need to make sure it is sealing. Rotate the cover above the centre of the housing. Put the handle on the handpump in the left position “down”. Use the handpump to lower the cover very carefully.
- Filling the tank
Before adding liquid into the tank, the valve positions should be checked.
The vent valve and the filter outlet should be open.
The liquid can now be added into the filter.
When the air is displaced from the filter, the liquid will meet the level indicator/switch, the vent valve must then be closed. It is essential that filling up the filter tank is not done too rapidly, as too much air may be entrapped in the plate cartridge underneath the filter paper. This may result in paper breakage.
- Pressure drop
The maximum pressure drop across the filter plates should not exceed 3,5 bar even if the filter tank is designed for higher pressure. The excess pressure differential between filter inlet and outlet may cause damage to the filter plates and/or of the plate screens.
- Filter media (filter paper)
The filter medium may be cloth or disposable media with specially formulated paper suitable for the application.
The filter media shall be placed in the right way to avoid any damage to the filter paper or problems during the process such as:
- Bleedthrough: check plate ring, hub, and centre cup for damage.
- Tears around the centre hole can indicate a fast filling problem.
- Cake erosion due to unaligned baffle.
- Thin cake toward the centre due to slow flow.
- Protecting the filter tank
The safety aspect must be checked to safeguard your filter tank against overpressure. This is different from the maximum allowable pressure differential over the filter plates.
In the case of a centrifugal pump, no precautions have to be taken if the no-load pressure is not higher than the design pressure of the filter tank.
- Cleaning of the filter cartridge
The cartridge is dismantled by the removal of the side tie-rods and top plate so that the filter plates can be taken off one by one for removal medium and cake.
- Lifting the filter
Never hoist the filter with the cover lifting facility or other fixing points, these could be bent and not function any longer. Always use the lifting lugs on the filters for correct lifting.
