In the wastewater treatment of sand and gravel system, the filter press is often used as the end mechanical treatment mode of solid-liquid separation, filtering materials through pressure, especially for the separation of slime, which has its unique advantages. The following are some common faults and treatment methods of filter press.
1. Damage of plate and frame
Causes:a) The mud is too thick or there is a dry block left, resulting in the blockage of the feed port. There is no other material between the filter plates, only the pressure of the hydraulic system itself. At this time, the plate itself is very easy to be damaged due to long-term pressure;b) When the feed is insufficient or there are improper solid particles in the feed, it will also cause excessive stress or damage to the plate frame itself;c) If the outlet is blocked by solid or the feed valve or discharge valve is closed when it is started, the pressure will not leak out, or even cause damage;d) If the filter plate is not cleaned thoroughly, it may cause medium leakage. As long as the medium leaks, the edge of the plate frame will be impacted by a small channel. A large number of medium leakage will certainly cause the pressure cannot be increased, so that the mud cake cannot be formed.
Methods:a) Carefully clean the scraper with nylon material to eliminate the mud falling into the feed port;b) Complete this cycle, reduce the volume of filter plate;c) Carefully check whether there is any problem with the filter cloth, and then check whether the drainage outlet is smooth, check whether the outlet is smooth, open the corresponding pressure valve, and release the pressure;d) Clean and repair the filter plate carefully.
2. Water seepage between plates and frames
Causes: a) low hydraulic pressure; b) wrinkles or gaps on the filter cloth, once they occur, replace the filter cloth in time; c) there is something like a block on the sealing surface.
Methods: Increase the hydraulic pressure, replace the filter cloth or use a nylon scraper to remove the unknown block on the sealing surface.
3. The formed filter cake is not even or in shape
Causes: too small feed particle size, too low concentration, insufficient feed, or outlet blockage and other problems, resulting in uneven distribution of filter cake, making it difficult to form filter cake.
Methods: adjust the process of production workers, improve the feeding, increase or reduce the supply of materials, clear the blockage, clear the feeding hole, clean the drainage hole, clean the filter cloth (or replace the filter cloth), increase the pressure or pump power, start the low pressure, and increase the pressure continuously.
4. The filter plate moves slowly or falls easily
Causes: sometimes, too much oil and dirt on the guide rod will cause the filter plate to walk slowly or even fall down, which is very dangerous.
Methods: clean the oil and stain on the guide rod in time, and apply grease to ensure the lubricity, so as to avoid accidents. It is strictly forbidden to apply thin oil on the pole, because the staff is easy to fall down and cause personal injury accidents.
5. Insufficient flow of hydraulic system
Causes: a) the oil pump does not drain oil; b) the setting pressure of the sequence valve is too low or the valve core is stuck at the opening position; c) the oil filter is blocked; d) the oil level of the oil tank is too low and the oil pump sucks air; e) the viscosity of the hydraulic oil is too large and it is difficult to suck oil; F) the parts in the pump are severely worn, the internal leakage is large and the pressure flow cannot reach the rated value.
Methods: a) repair the oil pump; b) repair the sequence valve; c) clean the oil filter; d) replenish the oil; E) change the oil or increase the oil temperature; F) repair or replace the oil pump.
6. Electrical failure
Wires are easy to fall off, wires are wrongly connected, parts are in poor contact or damaged, screws are not firmly screwed, etc., which are extremely easy to cause electrical failure.
For the treatment of electrical fault, it is necessary for the electrical personnel to firmly master the electrical principle knowledge, and also to properly master the basic principles and systems of various filter presses, so as to solve the electrical problems of filter presses in time when problems occur. During this period, priority should be given to the parts that are prone to problems to ensure the speed of maintenance, so as to prevent unnecessary losses.