The horizontal belt vacuum filter is shaped like a large belt conveyor. It is a high-efficiency filtration device that utilizes the gravity and vacuum suction force of the slurry to achieve solid-liquid separation. It has been widely used due to its outstanding advantages in terms of production capacity, washing efficiency and production cost. The products manufactured in Britain, the United States, the Soviet Union, Japan and other countries have a maximum specification of 185 m2 . China has developed more than 50 horizontal belt vacuum filters, and 20 m 2 is in the process of design. The main disadvantages of this type of filter are the large footprint and high investment. In addition, by vacuum filtration, the filter cake moisture is difficult to reduce.
There are many types of horizontal belt vacuum filters, and Fig. 1 is one of them. The rubber belt type vacuum filter differs from the belt conveyor in that it is covered with a layer of filter cloth on the tape, and the two advance simultaneously. The tape has a plurality of vertical and horizontal tapered grooves, such as the filter plate of the filter press, and a liquid outlet hole in the middle of the chute (groove). During operation, the eyelet communicates with the vacuum pumping tank below it. Due to the vacuum, the filter cloth wave is adsorbed on the tape, and the filtrate is sucked from the orifice into the vacuum receiver, and the filter residue is left on the belt surface. Re-recover the vacuum, suck the filter cake and continue to advance, so that the cycle is repeated.
Figure 2 is a belt filter with a pressure belt device. The filter cloth is both a filter medium and a conveyor belt, and the filter cloth is made of polyester fiber and polypropylene. The feed and filter cake discharge are continuous, but the vacuum is intermittent. The vacuum filter disc reciprocates. Since the synthetic fiber is used as the filter medium, the medium can be closely attached to the filter disc after the feeding, and the air is extremely easy to be airtight, and a high degree of vacuum can be achieved. The filter cloth is easy to replace. There is no relative friction between the filter cloth and the filter disc during the suction filtration process. [next]
Figure 3 is a reel vacuum filter. The filter is mounted on a plurality of laterally spaced conveyor belts, each of which is lined with a filter cloth 2, and the filtrate is vacuum-sucked through the bottom of the filter tray. The outlet tube is discharged by a retractable hose. Through the dispensing head arrangement, the filter is filtered at a certain position in each cycle, and the filter cake is discharged at another position. This kind of equipment is especially suitable for treating the slurry containing large particles and difficult to filter, which is difficult to filter by the drum vacuum filter, and can be washed many times, but the filter cloth can only be washed on one side, easy to block, and the filter cake is discharged. Difficulties, sometimes need to increase the backflushing device. Since the filter disc uses a two-rotation connection seal, the possibility of vacuum leakage in the entire system is increased, so the structure is complicated.
Figure 4 is a filter belt filter. The lower annular filter belt and filter cloth are mounted on a pair of rollers, and the filter belt and the filter cloth move simultaneously. The upper part is a ladder-like annular frame made of elastic material, pressed against the upper surface of the filter cloth, the filter frame and the filter cloth move synchronously, and the mud and the washing liquid can be injected into the designated filter frame respectively. During the forward movement, filtration, washing, drying, and the like are performed by vacuum suction. After completing the various processes, the filter belt, filter cloth and filter frame are separated by themselves and wound back to the starting position. Since the liquid fills the filter frame, the vacuum reduction caused by the imbalance of the slurry feed and the mixing of the washing liquid and the filtrate due to the backflow of the washing liquid are prevented. The device is simple in construction and the filter belt is not severely worn. [next]
Figure 5 is a multi-vacuum box belt filter. A plurality of vacuum suction boxes are arranged in the frame, and the two sides of the vacuum box are extended upward to form a rib, and each vacuum box has a conveyor belt (filter belt) for supporting the longitudinal movement of the filter cloth, which is covered with The filter cloth has a filter cloth width larger than the filter belt, so that the two sides of the filter cloth are tightly sealed with the two sides of the vacuum box, and after being fed at the feeding end of the machine, the filtration and washing are sequentially performed through the respective vacuum boxes. , drying process, the space between the top of the filter belt in the two vacuum box, can be placed measuring instruments and testing equipment for measuring the drainage rate of the filter cake, the material velocity and metal content. The structure is very simple.
