Filter Press Repair
Filter presses are regarded as investments made-to-last. Many operators have machines with service lives that have outlasted those of the manufacturers. For these customers, the team at R&W Filtertechnik has been committed for years to guarantee the continued operation of such presses by overhauling and refurbishing them. Naturally, this also applies to newer machines.
Inspection with preventive maintenance
Extended preventative maintenance, including an inspection, should be carried out by a specialist company. This is because during an inspection indications of wear limits and weak spots in particular should be detected and subsequently the appropriate measures can be taken. Electrical and mechanical components will be inspected, checked, adjusted and replaced, if necessary. All the appliances that require repairs or the replacement of parts will be identified and recorded in a summary report. Unlike unforeseen emergency repairs, preventive maintenance can be scheduled for times that are convenient for the operations flow of the machine.
It has been shown that all these measures maximise the service life of a filter press, significantly cut the cost of repairs and substantially reduce downtimes that occur due to breakdowns.
Service work on filter presses and maintenance covers:
- Machine frames
- Foundation points
- Filter plates and filter cloths
- Filter plate transport
- Suspension of filter plates
- Hydraulic cylinders
- Hydraulic power units
- Safety equipment / light curtains
Filter press brands
The R&W Service Team has the necessary experience to provide support for filter presses that covers all manufacturers and different origins. The following are just some examples of the brands of machines:
- Rittershaus & Blecher
- von Roll
- and many more.
Refurbishment of filter plates made of cast iron or steel
Just like the robust frames of filter presses, the filter plates made out of metal are also products with a long service life. Nevertheless, after years of operation, corrosion inevitably sets in. The life service of the plates can be extended by at least another ten years if the plates are re-coated using the electrostatic powder spray (EPS) process or the whirl sinter method.
- Re-coating using the EPS process or whirl sinter method
Filter plate transport mechanism (electromechanical, hydraulic)
For the smooth and safe operation of the filter press during cake emptying and filter cloth washing the filter plate transport mechanism has to function flawlessly. In this regard, it is important to carefully inspect and maintain the mechanical parts and to replace them preferably before they reach their wear limits.
- Drive unit
- Switching equipment
- Drive chains / belts
Overhaul of hydraulic cylinders and pistons
The condition of the lock cylinder is particularly important for ensuring a flawless filtration process and in order to comply with the necessary occupational health and safety measures. Therefore, regular monitoring and the routine replacement of sealing devices are recommended.
- Piston overhaul
- Replacement of pistons
- Sealing devices
- Reworking cylinder barrels
Replacement / retrofit for hydraulic power units in accordance with EN 982 (EC-MSFD)
It is not possible to operate a filter press without a reliable hydraulic control system. In the case of membrane filter presses, in particular, besides the 'BGR 500' (a directive on the operation of work equipment from the main federation of statutory trade associations for H&S at work and employer liability insurance) also other safety-related interlocks are required.
- Magnetic valve control
- Safety equipment
- Instrumentation and Control (I&C)
Filter plate guiding mechanism
In the case of both sidebar machines and filter presses where the plates are suspended overhead, the guiding components are subject to natural wear and tear due to abrasion or corrosion.
- DIN rails made of steel, stainless steel and synthetic material
- Plate handles for round and rectangular connector bars
Filter plates - Shifting device
With filter presses, the mechanism for shifting and locking the filter plates is generally exposed to dirt, humidity and, in some cases, chemical attacks. Therefore, after a longer period of use, various components will need to be replaced.
- Drive chains / belts and cables.
- Mechanical elements for plate shifting, plate locking / unlocking
There are many different models of filter presses with an overhead arrangement for the plate transport mechanism. In each case, the choice of material and the design are adapted to the specific operating conditions of the filter press.
- Models in steel, galvanised steel, or stainless steel
- Rollers and sliding members made of steel, stainless steel and synthetic material
- Bearings in maintenance-free and chemical-resistant quality
Head and thrust pieces with inner lining made from polypropylene or stainless steel
The wetted components of a filter press are often provided with standard corrosion protection only. Optimum protection can be achieved with a coating of PP or stainless steel.
Overhaul of filter cloth washing systems
Filter cloth washing systems are primarily used for the purpose of maintaining the rate of throughput of a filter press. Regular monitoring or replacement of the high pressure nozzles is recommended.
- Drive unit
Repair of all brands of trough chain conveyors
If the cake lift-off device does not work reliably, then the overall dewatering operations will not be possible.
- Replacement of conveyor chains
- Drive unit and reversing unit
Bunker cover, swivel plates, drip water trays
When filter cloth washing systems are used, or for the purpose of channelling off filtrate drips, the water is separately drained via movable bunker covers.
- Hydraulic cylinders, pneumatic cylinders
- Cover plates
- Hydraulic / pneumatic control systems