Plate pump: design, advantages, principle of operation, prices. Vacuum plate-rotor pump

Due to its distinctive characteristics and convenient design, the plate pump has become widely used 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.

The design has a heating jacket for pumping substances that acquire a thick consistency at low temperatures. The plate pump is used to move many types of liquids: mush, abrasive, with the presence of foreign small particles, as well as resins and sticky masses on their basis. It can be used for pumping through a hose, by lowering the intake pipes into the vessel. This device, in contrast to other types, has an increased suction capacity and operates with equal effort in both directions.

Design

The basis of the plate pump is as follows:

- Body 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 having different angles of inclination at the points to the exit of the faces are made.

Application

The plate pump, whose price is on the average 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 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 discharged with the right direction of the shaft movement. 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.

Features

As practice shows, the difficulties in extending the period of operation are associated with damage to the 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 transported 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.

A more perfect design is a plate-like NPL pump 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 casing. The 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 42 000 rubles, it is intended for use in metal cutting hydraulic drives and other devices that require a flow of working fluids that are not regulated in size, with a stable pressure.

What is required for the installation

A safety valve is installed to protect the hydraulic system and pump against overload. In this case, its settings must correspond to the nominal output pressure. The pipeline should 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.

Characteristics

The vacuum plate-rotary vacuum pump is evaluated according to the following properties:

- Pumping speed, detected by the volume of gas that 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.

- Outlet pressure at the outlet end. Its excess helps to increase the pressure in the intake. 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 principle of operation of the mechanism of the 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 takes place in one turn, which includes the suction and discharge process. There is also a division into unregulated and regulated. In the first embodiment, 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.

Advantages

Among the positive points, it is worth noting the following:

- Easy maintenance.

- Increased reliability.

- Reversibility.

- Longevity.

- Practically noiseless work.

- Easy installation.

- Economical.

The device of oil pumps

Spherical, plate-stator and rotary variants became widespread. 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 specified parts by the points of contact 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, sparseness appears, and the gas enters the vacuum mechanism from the chamber. The gas on the inlet side begins to contract and is released when the valve spring pressure is exceeded. The body of the mechanism is located in a container with oil, due to which all the gaps are sealed and the possibility of a reverse gas entry is excluded.

Oil types of plate pumps are not designed for pumping gas-vapor 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 begins to condense, with water mixing and is on the inlet side, where it evaporates again. So there is a cycle.

Gas ballast

Oil pumps use gas-ballast mechanisms for the release of moist air, which feed atmospheric dry air into the compression volume. Ballast gas contributes to the fact that the opening of the exhaust valve will start earlier than the partial pressure reaches the dew point, after which both vapor and gases are released. Gas ballast reduces the ultimate vacuum and reduces the speed of action, but at the same time the range of application of the device increases.

The plate pump requires the use of a vacuum specialized 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.