Due to the distinctive indicators and convenientThe design of the plate pump has become widespread in various industrial areas. It is used in the pharmaceutical, chemical, cosmetic industry, as well as in the food industry - for pumping condensed milk, molasses, glazes.
In the design there is a heating jacket forpumping substances that acquire a thick consistency at a low temperature. The plate pump is used to move many types of liquids: mush, abrasive, with the presence of foreign fines, as well as resins and sticky masses on their basis. It is possible to use for pumping through a hose, due to the lowering of the intake nozzles into the vessel. This device, in contrast to other types, has an increased suction capacity and operates with equal effort in both directions.
The basis of the plate pump is as follows:
- Housing with easy-disassembly device made of strong steel.
- Motor-reducer, which has an asynchronous powerful motor.
- A shaft with plates moving along an eccentric trajectory, they are made of bronze or its food substitute.
Near the grooves on the cylindrical surface in the direction of rotation, grooves are made having different angles of inclination at the points to the exit of the faces.
The pump is plate-like, the price of which isan average of 30-40 thousand rubles, is a hydraulic machine with volumetric displacement and working moving blades with reciprocating motion in relation to internal elements. It is used as a stationary and mobile unit in mechanical engineering, as well as in agriculture. When pumping liquids with foreign inclusions, it is important to take into account that if the permissible particle size is exceeded, they can be retained by the filter on the branch pipe.
Vacuum-plate pumps are produced with the rightdirection of the shaft. Manufacture with the left direction under the individual order is supposed. The mechanism is installed in any position. With the help of an elastic coupling, the drive shaft and the pump shaft are connected. It is not allowed to transfer axial and radial loads from the drive.
As practice shows, the difficulty in extendingperiod of operation are associated with damage to working plates damaged by interaction with abrasive particles that are in the pumped mass. The vacuum plate-rotary pump is designed for pumping liquids of all kinds, it has a body with a profiled plane, with injection and collecting windows. Among the shortcomings, it is worth noting the decrease in reliability indicators during the pumping of masses with foreign inclusions and various impurities. The transferred medium during the work passes to the pressure pipes from the retractors, while on the plane of the rotor and the body foreign particles adhere. If the dimensions of the elements in the liquid exceed the maximum permissible limit, there is a possibility of damage to the rotor of the device and the internal surface.
The pump has a more perfect designPlate NPL with injection and absorption windows on internal surfaces. This device has a rotor with grooves, installed in its cavities special plates, moving in the radial direction. The disadvantage of this design is the uneven wear of the surface of the plates, the inner lid, the body. Rear working faces and edges are unevenly worn due to pressure drops in the opening chamber and the pressure channel during the transition of the plate to the local area. In addition, it is worth noting the damage caused by the ingress of large particles into the gaps between parts that were not delayed by the channel filter.
The cost of this type of pump starts from 42000 rubles, it is intended for use in metal cutting hydraulic drives and other devices that require a flow of working fluids, not adjustable in size, with a stable pressure.
What is required to install
A safety valve is mounted for protectionhydraulic system and pump against overload. In this case, its settings must correspond to the nominal output pressure. The pipeline must have smooth bends and a good seal at the connection to the pump to prevent air from entering.
The working mass is poured into the mechanism before the first start, and the valve screw is unscrewed to zero settings.
The vacuum plate-rotor pump is evaluated according to the following properties:
- Pumping speed, detected by the volume of gas,which passes through the nozzle section at nominal pressure. If pressure changes in the system, then the same happens with the pumping speed. Dependence of the speed of action on pressure reveals the expediency of using the device at a given level of pressure.
- Final maximum pressure from the sideoutlet nozzle. Its excess helps to increase the pressure in the inlet. Some oil-plate pumps do not throw exhaust gas into the atmosphere. Accordingly, to maintain normal operation, a preliminary vacuum must be formed - this is the minimum pressure achieved by this device.
Types of mechanisms
In many respects determines the operating principle of the mechanismThe nature of the movement of gas in the operating pressure range. The gas flow, depending on the sparse, is carried out in the molecular, viscous or inertial regime. The pump can have a double or single action. In the latter case, a cycle of work occurs in one turn, which includes the suction and discharge process. There is also a division into unregulated and regulated. In the first variant, the mechanism can provide a continuous flow direction of the fluid, in the second, a mechanical valve adjustment is required. A single-stage plate pump can have two types of mechanisms. In two-fold modifications there is only an unregulated device.
Among the positive points, it is worth noting the following:
- Easy maintenance.
- Increased reliability.
- Practically noiseless work.
- Easy installation.
The device of oil pumps
Spool spools were widely used,plate-stator and rotary variants. The vacuum plate-rotary pump has an eccentrically rotatable mechanism, located in the cavities of which two plates are pressed against the surfaces of the housing. The working volume of the chamber is divided into predetermined parts by the contact points of the rotor, plates and walls, in particular to the intermediate, reducing the mass of the intake and increasing when moving. On the inlet side, as the volume increases, rarefaction appears, and the gas enters the vacuum mechanism from the chamber. The gas on the inlet side begins to contract and is thrown out when the valve spring pressure is exceeded. The body of the mechanism is located in the container with oil, due to which all gaps are sealed and the possibility of gas re-entry is excluded.
Oil types of plate pumps are notThey are designed for pumping steam-gas mixtures, for example, moist air. Due to the design features, the gas is compressed by the opening valve time. In this case, steam even with a small partial pressure in the chamber starts to condense, water is mixed with the oil and is on the inlet side, where it evaporates again. So there is a cycle.
In oil pumps are used gas ballastmechanisms for the release of moist air that deliver atmospheric dry air to the compression volume. Ballast gas contributes to the fact that the opening of the exhaust valve will begin earlier than the partial pressure reaches the dew point, after which the emission of both vapors and gases occurs. Gas ballast reduces the ultimate vacuum and reduces the speed of actions, but at the same time the spectrum of application of the device increases.
The plate pump requires a vacuumSpecialized oil, in which low-boiling fractions are absent due to the use of vacuum distillation. In places of friction, due to overheating, oil decomposition begins in the course of the work, light hydrocarbons subsequently appear. Thanks to them, the vacuum decreases and the vapor pressure increases.</ p>