The contents, type and quantity of auxiliary equipment associated with the filter vary depending on the type and specifications of the filter selected. In addition to the filter press and the centrifugal dewatering filter, the vacuum filter must be equipped with a filtrate cylinder and a vacuum pump. When using a non-self-weight or non-scraper to remove the filter cake, a low pressure compressed air device is required to blow off the filter cake. In addition, no matter which filter has filtrate collection, discharge and the corresponding pipe network system. B SZ type water ring vacuum pump SZ type water ring type vacuum pump has four specifications, the maximum vacuum degree can reach 90%. This type of vacuum pump can also be used as low pressure blower. At this time, the motor power increases correspondingly, and the maximum gauge pressure can reach 206 kPa (2.1 kg / cm 2). In order to maintain the volume of the water ring and eliminate the heat generated by the vacuum pump, the water in the water ring must be circulated and replenished continuously. To this end, a water tank is provided at the exhaust end of the SZ type water ring type vacuum pump, and a water supply pipe is provided: a communication pipe is provided between the water tank and the pump, and the amount of water added to the water ring is adjusted with the gate valve. The circulating water of the water ring vacuum pump should not contain mechanical impurities to prevent wear parts. [next] These two types of jet pumps are often used in condiments to transport clean water or chemicals, as well as to transport slurries. In recent years, it has also been used for filtration operations instead of water ring vacuum pumps. When the jet pump is working, it converts the energy of other liquids or gases into the potential energy of the liquid to be transported, thereby achieving liquid transport. [next] Where V is the water jet pumping capacity, m 3 ; Where N V is the power consumed by the displacement capacity of 1 m 3 /min, kw / (m 3 · min); Pallet Positioning,Conveyor Positioning,Pallet Locate,Conveyor System,Pallet Conveyor System Vitrans Automation Equipment Co.,Ltd , https://www.vitrans-automatic.com
(1) During the working process of the vacuum pump sorting filter, air must be drawn from the filter chamber to make the absolute pressure in the chamber lower than the atmospheric pressure. The pressure difference between the two is usually measured by vacuum or vacuum gauge pressure (gauge pressure). The degree of vacuum is generally expressed as a percentage of the negative pressure (i.e., the gauge pressure of the vacuum gauge) formed by suction in the filter chamber (and the connected network) as a percentage of atmospheric pressure. Thus, processing plants often directly measure of the degree of vacuum with a pressure gauge readings (vacuum gauge pressure) vacuum table.
The filter of the concentrator is generally in a low vacuum state, that is, the air in the filter chamber is not fully extracted, but the residual pressure is very low. This is mainly due to factors such as the performance of the vacuum pump and the degree of sealing of the filter network. The vacuum pump's clearance volume, air temperature, humidity and air leakage will cause the actual inhalation to decrease. At present, the maximum vacuum degree of domestic vacuum pump: water ring type can reach 93~96%, spray type can reach 94~95%, reciprocating type can reach 95%. When the vacuum pump of the concentrator filter operation works, the vacuum degree should generally reach 85% or more. .
Vacuum pumps can be divided into rotary and piston types. The former can simultaneously suck gas and mixed misty filtrate, called wet vacuum pump; the latter can only pump gas, which is called dry vacuum pump. Two kinds of vacuum pumping volume vacuum means under certain conditions, the unit time within the gas sucked into and standard atmospheric conditions, i.e., temperature is 0 ℃, pressure of 101 kPa (760 mmHg) when The volume of air.
At present, the vacuum pump used more by the concentrator is a water ring vacuum pump. A few concentrators use a jet vacuum pump.
Water ring vacuum pumps are currently available in two models. Among them, the SK type water ring vacuum pump has better performance than the SZ type water ring type vacuum pump.
A SK water ring vacuum pump SK type water ring vacuum pump is a single-stage double suction ring vacuum pump, generally used to pump non-corrosive gas without solid particles, and allows liquid to enter the pump at the same time, but gas and liquid The temperature should not exceed 40 ° C.
The structure of the SK type water ring vacuum pump is shown in Figure 1. 
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The structure of the SZ type water ring vacuum pump is shown in Figure 2. Its working principle is similar to that of the SK pump, but the internal structure and working efficiency are quite different.
C Jet pump The jet pump has a simple construction. The structure of the water jet pump is shown in Figure 3, and the results of the steam jet pump are shown in Figure 4.
The concentrator generally uses a jet pump that uses water as the working fluid to transport the filtrate. The clean water is pressed into the water chamber of the jet pump by the water pump, and is kept into the mixing chamber at 147 kPa (1.5-30 m/s). After a certain distance, the water flow from each nozzle is accurately concentrated at one point in the center of the throat ( Focus). The transverse flotation of the high-speed jet diffuses and takes away the air inside the straw to form a low pressure. The air in the filtrate tank of the filter enters the mixing chamber along the suction pipe of the jet pump and exchanges energy, so that the flow velocity of the working fluid is reduced, the flow rate of the sucked air is increased, and the flow velocity of the two at the outlet of the throat is increased. Consistently, the pressure gradually increases. After the mixed fluid passes through the diffuser, most of it can be converted into pressure, so that the pressure head is further increased, and finally discharged into the water tank through the tail pipe. Steam blast pumps can also be used in concentrators with cheap steam.
The pumping capacity of the pump makes the pumping capacity of the water jet pump the capacity K of the water jet pump. It can be calculated by:
Q——The water supply of the pump, m 3 .
The K value varies with the degree of vacuum. The relationship between the K value of the water jet pump with different structure and the change of the vacuum degree is different.
The power of the water jet pump with the water pump can be calculated by the following formula:
H——water chamber gauge pressure, kPa;
N——water pump power, kW;
V——water jet pumping capacity, m 3 /min;
K——Discharge coefficient.