Centrifugal single-stage water pump: circuit. Cantilever single-stage centrifugal pump. Vertical centrifugal single-stage pump

Centrifugal single-stage pump of console type Designed for pumping stations. The most commonly used equipment at water installations is general-purpose equipment. For the most part, two-way pumps of type D are installed at the stations, and if necessary large volumes are used for console devices.

Vertical Pumps

The vertical centrifugal single-stage pump is used at buried stations, the construction of which is difficult in conditions of too close a water level. This makes it possible to reduce the cost of construction, reduce the size of the engine room, improve the quality of operating conditions for electric motors, which can be carried to the first floor.

Axial Pumps

Such installations are most often used for large water supplies. Sewage dynamic pumps are mostly installed at stations of waste disposal systems. The water temperature is up to 80 degrees and the possible content of up to one percent of abrasive particles. In the sewerage systems, the types of Gy and Gy type can also be used.

Centrifugal single-stage pump and its properties

The operational characteristics of such pumps are determined by their main parameters: power, head, cavitation reserve, feed, suction height. The important qualities of the operation of the units are the voltage of the electric motor and the speed of the wheel.

It should be understood that the parameters of the axial and centrifugal pumps are variable even with the continuous action of the impeller and will depend on the feed. In the drawings, it is customary to give characteristics for reduced wheel diameters. The characteristics of the optimum mode points correspond to the maximum efficiency. The appropriate set and feed are acceptable indicators of the pump. These characteristics are entered in the designation of installations.

Operating point

The operating point is the position corresponding to the current mode of action. It does not always coincide with an acceptable indicator, but must necessarily be approximate to them. A single-stage centrifugal water pump always functions within the working part, which is determined in accordance with the permissible reduction in efficiency. Work points should be only within these limits. The characteristics of each device are described by the manufacturer with the calculation for clean water at a temperature of twenty degrees at the optimum atmospheric pressure at the ocean level.

Pumps of types K and KM

A centrifugal single-stage horizontal pump operates with a one-way impeller located at the edge of the pump shaft. Pressure nozzles are rotated through 90, 180, 270 degrees. This depends on the specific layout conditions. Bearings in the mechanisms are lubricated with a liquid substance. The cantilever single-stage centrifugal pump can have several modifications: installation without an engine (K) and in a monoblock version (KM). After these letters, the marking indicates the feed and head.

Installations with a double-sided supply

On the market, single-stage horizontal pumps of class D with a semi-helical feed are available. The horizontal lifting of the cast iron body is carried out in the plane of the axis of the shaft. This feature makes it possible to disassemble and repair the device without having to dismantle the pipeline. Each two-way pump is marked with a "D" symbol. After this letter two figures are indicated: feed and head.

What does the console installation consist of?

A single-stage centrifugal water pump consists of such parts: a spiral housing outlet, a support, a front cover, an impeller, a suction pipe, a nut, a shaft, a gland bush, a ball bearing.

The principle of connecting components

With the help of discharge openings, the axial pressure is partially balanced. Also the wheel is supplied from the rear with an axial seal. The tube with the connection is connected to the pump discharge chamber. The second ball bearing is installed to fix the rotor and better perception of the unbalanced axial force. A hydraulic seal is provided on the oil seals.

Such installations have a capacity from 28 to 100 liters per second with a head from 12 to 98 meters. High-performance single-stage pumps mostly have the possibility of a two-way approach. At normal axial pressure, a good two-flow wheel has sufficiently high cavitation performance.

Housing and gaskets

In pumps designed for pumping clean liquid with a temperature of up to 80 degrees, there is a cast-iron casing with horizontal connectors along the axis of the shaft. Replaceable O-rings are made of cast iron. The pump shaft is made of steel and rotates on one thrust and radial bearing with ring grease.

Seals are equipped with a water seal, which is carried out with the help of tubes that supply liquid from the spiral chambers. Such a single-stage centrifugal pump of cantilever type has a productivity of 30 to 1800 liters per second and a head from 10 to 100 meters.

Vertical shaft plants

Two brands of single-stage devices for pure water are produced: 20 HB and 28 HB. They are designed for installation in buried stations. In this installation, the heel of the electric motor receives axial forces. On the oil seal of the pump is provided a hydraulic shutter with a soft packing. Type HB units are directly connected to electric motors or by means of hard seated clutches through an intermediate shaft. The vertical centrifugal single-stage pump has a capacity of 3240 to 10,800 cubic meters per hour and a head from 29 to 40 meters.

Features of sewage pumps

A centrifugal single-stage pump is used for pumping sewage, sewage and sludge. One of the main reasons for stopping pumps during use is their clogging. To protect against the ingress of debris into the mechanisms are provided special gratings. Their installation necessitates changing the shape of the installation.

Such pumps are sealed with steel rings with a sharp edge, which cuts the fibers that enter the seals. The units are equipped with lids providing easy access for cleaning the suction part of the impeller. The number of blades is minimized to reduce the possibility of clogging. Passages between them, thus, increase. Quite often the number of blades is reduced to two.

Cantilever single-stage centrifugal sewage pump is created from materials not subject to corrosion. In its case there are several connectors necessary for partial disassembly during the cleaning process. The input edges of the blades are rounded very strongly. Due to this fibrous bodies on them will not get stuck.

Pumps brands NF, NFUV and FV. Open and diagonal devices

There are such types of installations: 2NF, 4NF, 6NF, 8NF. Their capacity ranges from 36 to 864 cubic liters per hour with a head from 6.5 to 50 meters. Similarly to such installations, sewage pumps with an open impeller with two thick blades can be used. In such devices, all fibers are cut by the sharp edge of the blade.

For working with sewage, a single-stage centrifugal diagonal pump is often used. The impeller in these plants, as well as in the models of FV and NFUV grades, is equipped with two blades. Their productivity varies from 43 to 150 cubic meters per hour, and the head reaches 63 meters.

Dredging pumps

Dredgers are used during pumping through the pipes of mixtures of loosened soil and liquid to the required distance. Today the market produces pumps with a range of transportation up to 5 km and a productivity of 40 to 1,200 cubic meters per hour. With the help of dredging pumps, it is possible to develop excavations with a depth of up to 15 m below the water horizon. These plants have a number of features due to the large concentration of coarse particles in the pumped water mass. For this reason, a wear-resistant wheel made of manganese hard steel is produced.

The vertical centrifugal single-stage pump is protected by armor on the inside of the body to prevent rapid wear. To ensure that the mechanism does not come into disrepair so quickly, cleared water is supplied between the wheel to the left cavity and to the gland by special drilling to wash out solid fragments from these places.

Radial blades are installed on the outer part of the working and covering discs of the wheel. They are selected so that the axial amplifier comes into balance during the rotation.

Vacuum pumps

A single-stage centrifugal pump with a vacuum device is created in two basic versions: dry, sucking only gas, and wet, working also with the liquid. The difference can only be determined from the distribution nodes. In wet pumps, the size of dead space is much larger, so they have a higher limit pressure than dry ones. The highest frequency of rotation during operation is achieved by samples with a vertical shaft arrangement.

Non-self-priming device

Non-self-priming single-stage centrifugal pump is used for pumping milk or other viscous food products, the temperature of which does not exceed 90 degrees. The working blades of the wheel are closed and each part of such an installation in contact with the liquid is made of good stainless steel and other materials that can be used in the food industry. The engine protects against water ingress of a special cladding cover.

Conclusion

A centrifugal single-stage pump, the circuit of which is described in this article, can be used in a wide variety of applications. From the method of application and pumped materials will depend on the performance characteristics of such plants, as well as the material of which the parts are made and the way they are placed in the mechanisms. Pumps can be used for distilling clean water, a mixture of liquid and dirt, sewage waste and food grade of various viscosities.

The mechanisms intended for pumping liquids used for food are made of high-quality materials, the use of which is allowed by the Ministry of Health. Pumps that are used to drain sewage liquids containing large fibers are arranged in such a way that large parts dissect and do not interfere with the normal operation of the mechanisms.