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- Feb 25, 2007
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Some time ago 4metals was discussing filter presses for use in refining. They're very handy for filtering large volume of solutions and can be a valuable asset.
Filter presses vary considerably in how they deal with effluent. In cases where solutions are not particularly valuable, or where contamination of the effluent isn't an issue, it often is simply allowed to flow from each of the filter members, accumulating in a catch basin. An example of such an application might be one where properly treated waste solutions are separated from solid wastes, so the solution can be discharged to a sewer system, with the solids sent to hazardous waste disposal facilities. There is no affluent return circuit in the plates. That type of plate would not be satisfactory for the recovery of solutions of great value, or solutions that must be kept clean.
In such a case, the design of the plates is of such a nature that the solution is channeled from the plates to a circuit that dispenses the solution to an accumulation chamber. Such plates are considered to be fully gasketed, and are the type often used in refining. The picture posted by 4metals is of such a plate, and while the plates, below, vary somewhat, they function the same way.
I had suggested I would post some pictures of a filter press I built for use in filtering cyanide solutions from my agitation tank, but they had to be copied from a photo album first. I found time to accomplish the task when my modem died, leaving me without access to the forum for several days. Hope you find this interesting
The press pictured is closed by the ten ton hydraulic cylinder, a necessity to overcome the pressure developed by the slurry pump. Because the amount of travel of the cylinder is minimal, and the press is closed only infrequently, the press is equipped with a hand pump, capable of producing 10,000 psi hydraulic pressure. Slurry is introduced to the press via the large center opening of the plates, which align with the center of the head plate, where the press manifold is located. The four corner O rings form the channels that carry the solution from the press. There are channels under the filter media that cover each plate, directing the filtered solution to the ports, and, in turn, from the press, where they are stored the large black barrel nearest the press. The large O ring seen on each face serves a dual purpose, one of which is to secure the filter medium, with the other to seal the plates when under pressure from the hydraulic cylinder.
This press was built to filter cyanide solutions from an agitation tank. While they are similar in construction, the plates were machined from polypropylene, with stainless hardware.
The slurry pump is a diaphragm pump that is air driven. Such pumps will operate until they stall, with no damage to the pump. The two black containers function as a storage system for both the slurry and the filtered solution. They were plumbed such that each could function as the supply for the pump, so the initial discharge, which may not be free of flocculence, can be recycled until the discharge is clean. Filtering with a press is much the same as filtering by funnel, whereby the initial discharge may not be clean, but it slowly improves as the filter media gets covered with solids, quickly yielding a crystal clear solution.
The press was provided with a manifold system that permitted blowing down with compressed air, so the press could be fully emptied of solution.
Harold
edit: corrected spelling
Filter presses vary considerably in how they deal with effluent. In cases where solutions are not particularly valuable, or where contamination of the effluent isn't an issue, it often is simply allowed to flow from each of the filter members, accumulating in a catch basin. An example of such an application might be one where properly treated waste solutions are separated from solid wastes, so the solution can be discharged to a sewer system, with the solids sent to hazardous waste disposal facilities. There is no affluent return circuit in the plates. That type of plate would not be satisfactory for the recovery of solutions of great value, or solutions that must be kept clean.
In such a case, the design of the plates is of such a nature that the solution is channeled from the plates to a circuit that dispenses the solution to an accumulation chamber. Such plates are considered to be fully gasketed, and are the type often used in refining. The picture posted by 4metals is of such a plate, and while the plates, below, vary somewhat, they function the same way.
I had suggested I would post some pictures of a filter press I built for use in filtering cyanide solutions from my agitation tank, but they had to be copied from a photo album first. I found time to accomplish the task when my modem died, leaving me without access to the forum for several days. Hope you find this interesting
The press pictured is closed by the ten ton hydraulic cylinder, a necessity to overcome the pressure developed by the slurry pump. Because the amount of travel of the cylinder is minimal, and the press is closed only infrequently, the press is equipped with a hand pump, capable of producing 10,000 psi hydraulic pressure. Slurry is introduced to the press via the large center opening of the plates, which align with the center of the head plate, where the press manifold is located. The four corner O rings form the channels that carry the solution from the press. There are channels under the filter media that cover each plate, directing the filtered solution to the ports, and, in turn, from the press, where they are stored the large black barrel nearest the press. The large O ring seen on each face serves a dual purpose, one of which is to secure the filter medium, with the other to seal the plates when under pressure from the hydraulic cylinder.
This press was built to filter cyanide solutions from an agitation tank. While they are similar in construction, the plates were machined from polypropylene, with stainless hardware.
The slurry pump is a diaphragm pump that is air driven. Such pumps will operate until they stall, with no damage to the pump. The two black containers function as a storage system for both the slurry and the filtered solution. They were plumbed such that each could function as the supply for the pump, so the initial discharge, which may not be free of flocculence, can be recycled until the discharge is clean. Filtering with a press is much the same as filtering by funnel, whereby the initial discharge may not be clean, but it slowly improves as the filter media gets covered with solids, quickly yielding a crystal clear solution.
The press was provided with a manifold system that permitted blowing down with compressed air, so the press could be fully emptied of solution.
Harold
edit: corrected spelling
