Advantages of frame shaft disc filter
- No requirement for installation height, save cost;
- High degree of automation and remote centralized control is available;
- Easy installation and less area occupied;
- Less energy consumption, high pulp yield and high security.
Frame Shaft Disc Filter of CNBM
The ZPK35 frame shaft disc filter is a series of new structural product that is designed for the white water recovery or pulp concentration. It is based on the central axis disc filter. The frame shaft disc filter is made up of a cell body, a frame spindle, a filter disc, a spindle water tube seal device, a stripping device, a wite cleaner, a discharge screw, an upper canopy, a transmission device, and a control system. The frame shaft disc filter is a kind of continuous rotary filter device. The liquid level difference between the inside and outside of the sector plate is used as the filtering power, no vacuum is required, and the structure is compact and efficient.
Operation Principle of ZPK35 Frame Shaft Disc Filter
The filter disc is made up of several fan-shaped plates of the same size and equal area. The fan-shaped plates are suspended and mounted on the frame main shaft of the filter. When the equipment is running, for each piece of fan-shaped plate in the filter state, the filtrate outlets are at the lowest position. During the working process, with the running of the main shaft, the pulp suspension enters the tank through the feed tank. When the sector plate is below the liquid level, there is a liquid level difference between inside and outside the fan-shaped plate. Under the action of the liquid level difference, The water enters the fan-shaped plate through the filter screen covering the outside of the fan-shaped plate, and flows through the filtrate passage of the hollow rotor arm to the turbid filtrate area, the clear filtrate area and the ultra-clear filtrate area at both ends of the tank body, and then flows out through the corresponding pipes of the respective zones, and the pulp flows out. The material is intercepted by the filter to achieve separation of the pulp. When the fan-shaped plate is turned out of the liquid surface, the suction effect formed by the liquid level difference does not disappear immediately, and the pulp layer on the filter screen is continuously dehydrated, and the concentration continues to increase.
The spindle continues to rotate, the suction effect formed by the liquid level difference disappears, and the sector plate enters the stripping zone.The pulp on the sector plate falls off under the dual action of the gravity and the fan-shaped water jet sprayed by the stripping nozzle, through the space between the two adjacent sector plates, and enters the pulp collection tank formed by the main shaft of the frame and the sector plate without any obstruction. Next, pulp is conveyed to the receiving pipeline by a screw conveyor. When the filter disc is rotated to the washing area, the net is washed by the swinging washing nozzle, and the filtering capacity is restored, and then the next filtering cycle is entered. As the filter disk continues to rotate, the sector plates are in different zones, creating a continuous filtering effect.
Parts of ZPK35 Frame Shaft Disc Filter
Tank body or cell body is used to undertake the pulp, welded by steel plate, the material of the tank is determined according to the user’s process. The tank body consists of left and right wall panels, tank bottom plate, feed tank, filtrate pipe, main shaft sealing and other devices. There are interfaces on the tank, such as stock inlet, sewage outlet and liquid level transmitter. There are filtrate partition plates at both ends of the tank body to ensure running of equipment, the discharge outlet of each rotor arm of the rotary spindle is successively connected with the turbid filtrate tube, the clear filtrate tube and the ultra-clear filtrate tube to achieve filtration or concentration.
The main shaft is a network dragon rotor arm structure with a stirring function composed of a transmission side sub-plate, a non-transmission side sub-plate and a plurality of trapezoidal hollow steel.
The filter disc is the main body of the frame shaft disc filter, which is used to filter the pulp and form a pulp layer on the surface of disc. Each filter disc consists of several stainless steel fan-shaped plates. The fan-shaped plate is equipped with a plug-in filter. The filter mesh adopts a plug-in structure. The filter mesh does not need to be disassembled. One end of the sector plate is bolted to the hollow trapezoidal steel stirring rotor arm of the main shaft, and is respectively connected with the rotor arm flow channel of the outer frame main shaft. The discharge outlet of fan plate and the rotor arm flow channel are sealed by a rubber pad, and the other end is fixed to another rotor arm by the adjusting plate. The spindle drive end is supported by the rolling bearing on the bracket of the cell body, and the suspended hollow shaft reducer is suspended on the shaft end of the transmission. The bottom of the reducer is provided with a torsion arm to ensure smooth transmission of the reducer. The other end is supported by a bracket on a bracket inside the tank. An internal pressurized large-diameter sealing device is used between the main shaft and the tank body. When the equipment is running, pressurized water is introduced into the water tire to ensure that the pulp does not leak when the tank body and the main shaft are operated.
The upper canopy is composed of left and right wall panels, intermediate beams and movable cover doors, and the stripping device is supported on the left and right wall panels of the upper canopy, and the position of the stripping point is adjusted by U-bolts. Open the movable door to observe the operation of each part of the equipment.
The wite cleaner consists of a main pipe, a Z-shaped branch pipe, a nozzle, a joint elbow, a crank rocker mechanism, a speed reducer and etc. According to the set position, the washing branch pipe can swing back and forth within a certain angle range, and the washing nozzle located on the branch pipe flushes the filter screen with the swing to restore the filtering ability.
The stripping device is composed of a main pipe, an inner and outer wire flat joint connecting elbow, a stripping nozzle, a different diameter inner joint and etc. With water of pressure greater than or equal to 0.8, the fan-shaped water column is sprayed by the fan nozzle, and the pulpy layer on the filter disc is peeled off. The spray pipe and the main pipe are connected by a threaded hose, which can conveniently change the direction of the water column and adjust the stripping position.
Screw discharge device
The screw discharge device is composed of a reducer, a screw shaft, a spiral groove body, a water bearing and a sealing device. During operation, the screw shaft is driven by the reducer to rotate, and the pulp entering the spiral groove body and being broken up and transported to the receiving pipe through the discharge port.
The transmission device is composed of a frequency conversion motor and a suspended hollow shaft reducer. The spindle head of the filter disc directly protrudes into the hollow shaft of the reducer, and is connected by a key, so that one end of the reducer is suspended on the drum shaft, and the other end is supported by a pull rod. The speed of the filter disc is selected according to the process needs to be the optimum speed in 0.7-2.5r/min.