Multistage pumps - design, principle of operation and types of equipment

Very often, in order to ensure maximum comfort in a country house, it is necessary to use various auxiliary equipment.

The most optimal option for water supply units are multi-stage centrifugal pumps.

With the help of pumping equipment of this type, the pressure in water supply systems is effectively increased, which in turn contributes to their effective use, both in private households and in apartment buildings, as well as their industrial use.

Therefore, in this article we will try to disclose in as much detail as possible information about what multistage centrifugal pumps are, what their design and principle of operation are, and we will also talk about the types of this pumping equipment.

  • 2 Device
  • 3 Operating principle
  • 4 Types

Purpose of multistage pumps

The main task that a multistage pump must cope with is to create the maximum possible pressure in the water supply system. In other words, units of this type are designed for pumping water and other non-aggressive liquids, the temperature of which can reach 100 °C.

Other areas of equipment operation include:

  • Watering and irrigation of agricultural land;
  • Supporting uninterrupted water supply at public utilities;
  • Ensuring the operation of fire extinguishing systems in automatic mode;
  • Support for drainage in mines;
  • Cooling of steam boilers at boiler plants;
  • Intake and pumping of non-aggressive substances and compounds in the chemical industry.

From the listed areas of use, we can conclude that pumps of this type are used primarily for water. When working with this liquid, the downhole unit can create the strongest pressure and perform its functions stably for a long time.

Sectional pumps (CNS, TsNSG)

The group of CNS and CNSG pumps presented here is one of the main industrial pumps used in public utilities for hot and cold water supply and heating. The central nervous system pump is a sectional, centrifugal, booster pump. Consists of a cast iron body and rotor. The pump body of the TsNSG and TsNS includes suction and discharge covers, guide vane housings, guide vanes and brackets. The housings of the guide vanes and covers are tightened with coupling bolts. Sectional pumps TsNS and TsNSG are equipped with three-phase asynchronous electric motors of general industrial design. These pumps have a double soft seal. The permissible “leakage” through the seal is no more than 3 l/h. The permissible excess pressure at the pump inlet is no more than 0.35 MPa (3.5 kgf/cm2). Multistage pumps TsNS and TsNSG are designed for pumping cold and hot water, with temperatures from +1°C to +105°C. with a content of mechanical impurities of no more than 0.2 mm.

The structure of the pump designation indicates the type and parameters: pump TsNS300-180 – Centrifugal Pump Sectional for pumping water with a water temperature from +1°C to +45°C and a capacity of 300 m3/hour, a head of 180 m. If the pumping unit pumps hot (up to + 105°C) water – the designation contains the letter “G” (hot) – for example TsNSG38-176. A distinctive feature of CNS type pumps from others is the sectional design of the casing, which allows you to increase or decrease the pump pressure while maintaining the same flow rate. For example, by adding one section to the TsNSG38-176 pump, we, while maintaining a productivity of 38 m3/hour, obtain a head of 198 m and, accordingly, a TsNSG38-198 pump. In addition to TsNS pumps and TsNSG pumps, the industry produces such varieties of pumps of this type as pumps for pumping oil (TsNSN), transformer oil (TsNSM) and pumping water with high mineralization from coal mines (TsNSK series of pumps, the material of the flow part is made of chromium-nickel steel). Typically, pumps in this design are combined with explosion-proof electric motors. The CNSG pump differs from the CNS pump only in the maximum permissible water temperature.

ModelSupply m3/hHead mEngine kW/rpmDimensions mmWeight, kgPrice with VAT
CNS(G) 13-7013.070.0 mwithout frame and engine839x420x430 mm257.557,000 rub.Order
CNS(G) 13-7013.070.0 m11.0/30001387x420x561 mm335.0RUB 77,800Order
CNS(G) 13-10513.0105.0 mwithout frame and engine910x420x430 mm294.5RUB 65,350Order
CNS(G) 13-10513.0105.0 m11.0/30001458x420x561 mm372.0RUR 86,200Order
CNS(G) 13-14013.0140.0 mwithout frame and engine981x420x430 mm289.0RUB 69,700Order
CNS(G) 13-14013.0140.0 m15.0/30001626x420x621 mm415.0RUB 97,100Order
CNS(G) 13-17513.0175.0 mwithout frame and engine1052x420x430 mm319.074,000 rub.Order
CNS(G) 13-17513.0175.0 m18.5/30001697x420x621 mm457.0RUB 104,700Order
CNS(G) 13-21013.0210.0 mwithout frame and engine1123x420x430 mm334.0RUB 75,700Order
CNS(G) 13-21013.0210.0 m18,5/30001768x420x621 mm494.0110,000 rub.Order
CNS(G) 13-24513.0245.0 mwithout frame and engine1194x420x430 mm389.0RUB 87,500Order
CNS(G) 13-24513.0245.0 m22.0/30001839x420x640 mm549.0RUB 124,100Order
CNS(G) 13-28013.0280.0 mwithout frame and engine1265x420x430 mm395.0RUB 93,100Order
CNS(G) 13-28013.0280.0 m30.0/30001935x420x640 mm575.0RUB 141,500Order
CNS(G) 13-31513.0315.0 mwithout frame and engine1336x420x430 mm432.0RUB 100,800Order
CNS(G) 13-31513.0315.0 m30.0/30002006x420x640 mm612.0RUB 149,500Order
CNS(G) 13-35013.0350.0 mwithout frame and engine1407x420x430 mm469.0110,000 rub.Order
CNS(G) 13-35013.0350.0 m30.0/30002077x420x640 mm649.0166,000 rub.Order
CNS(G) 38-4438.044.0 mwithout frame and engine839x450x430 mm306.0RUR 49,600Order
CNS(G) 38-4438.044.0 m11.0/30001387x450x578 mm382.071,000 rub.Order
CNS(G) 38-6638.066.0 mwithout frame and engine910x450x430 mm335.0RUB 52,800Order
CNS(G) 38-6638.066.0 m15.0/30001555x450x621 mm405.0RUB 86,300Order
CNS(G) 38-8838.088.0 mwithout frame and engine981x450x430 mm376.0RUB 56,200Order
CNS(G) 38-8838.088.0 m18.5/30001626x450x621 mm446.092,000 rub.Order
CNS(G) 38-11038.0110.0 mwithout frame and engine1052x450x430 mm327.0RUB 60,500Order
CNS(G) 38-11038.0110.0 m22.0/30001722x450x640 mm487.0RUB 101,500Order
CNS(G) 38-13238.0132.0 mwithout frame and engine1123x450x430 mm390.0RUB 65,200Order
CNS(G) 38-13238.0132.0 m30.0/30001792x450x640 mm570.0RUB 119,800Order
CNS(G) 38-15438.0154.0 mwithout frame and engine1194x450x430 mm439.0RUB 71,700Order
CNS(G) 38-15438.0154.0 m30.0/30001864x450x640 mm619.0RUB 124,500Order
CNS(G) 38-17638.0176.0 mwithout frame and engine1265x450x430 mm578.0RUR 71,530 RUB 75,300 Order
CNS(G) 38-17638.0176.0 m30.0/30001935x450x640 mm758.0RUB 127,800Order
CNS(G) 38-19838.0198.0 mwithout frame and engine1336x455x430 mm546.0RUB 82,700Order
CNS(G) 38-19838.0198.0 m37.0/30002059x455x685 mm781.0RUB 147,900Order
CNS(G) 38-22038.0220.0 mwithout frame and engine1407x455x430 mm658.0RUB 88,600Order
CNS(G) 38-22038.0220.0 m45.0/30002195x455x685 mm913.0RUB 153,500Order
CNS(G) 60-6660.066.0 mwithout frame and engine870x525x500 mm356.0RUB 59,600Order
CNS(G) 60-6660.066.0 m22.0/30001540x525x676 mm516.0RUB 100,900Order
CNS(G) 60-9960.099.0 mwithout frame and engine850x525x600 mm442.0RUB 62,200Order
CNS(G) 60-9960.099.0 m30.0/30001620x525x676 mm622.0RUB 114,900Order
CNS(G) 60-13260.0132.0 mwithout frame and engine1030x525x500 mm513.0RUB 68,900Order
CNS(G) 60-13260.0132.0 m45.0/30001818x525x715 mm768.0RUB 135,000Order
CNS(G) 60-16560.0165.0 mwithout frame and engine1110x525x500 mm554.0RUB 75,200Order
CNS(G) 60-16560.0165.0 m55.0/30001930x525x731 mm890.0RUR 151,900Order
CNS(G) 60-19860.0198.0 mwithout frame and engine1190x525x500 mm578.082,000 rub.Order
CNS(G) 60-19860.0198.0 m55.0/30002008x525x731 mm918.0RUB 159,000Order
CNS(G) 60-23160.0231.0 mwithout frame and engine1270x530x500 mm585.0RUB 85,900Order
CNS(G) 60-23160.0231.0 m75.0/30002190x530x790 mm1060.0RUB 189,600Order
CNS(G) 60-26460.0264.0 mwithout frame and engine1350x530x500 mm611.0RUB 95,100Order
CNS(G) 60-26460.0264.0 m75.0/30002270x530x790 mm1086.0RUB 196,600Order
CNS(G) 60-29760.0297.0 mwithout frame and engine1430x530x500 mm637.0RUB 101,600Order
CNS(G) 60-29760.0297.0 m75.0/30002350x530x790 mm1112.0RUB 203,300Order
CNS(G) 60-33060.0330.0 mwithout frame and engine1510x560x500 mm562.0110,000 rub.Order
CNS(G) 60-33060.0330.0 m110.0/30002470x560x790 mm1282.0RUR 249,400Order
CNS 105-98105.098.0 mwithout frame and engine1075x425x620 mm480.0RUB 124,800Order
CNS 105-98105.098.0 m55.0/30001893x425x920 mm950.0200 300 rub.Order
CNS 105-147105.0147.0 mwithout frame and engine1170x455x620 mm518.0RUB 138,000Order
CNS 105-147105.0147.0 m75.0/30002093x455x930 mm1120.0RUR 231,000Order
CNS 105-196105.0196.0 mwithout frame and engine1265x475x620 mm576.0RUB 150,600Order
CNS 105-196105.0196.0 m110.0/30002103x475x940 mm1186.0RUR 289,000Order
CNS 105-245105.0245.0 mwithout frame and engine1360x535x620 mm634.0RUB 165,000Order
CNS 105-245105.0245.0 m132.0/30002548x535x935 mm1609.0RUB 319,000Order
CNS 105-294105.0294.0 m160.0/30002398x330x845 mm1571.0460,000 rub.Order
CNS 105-294105.0294.0 mwithout frame and engine1455x330x620 mm715.0RUB 183,000Order
CNS 105-343105.0343.0 mwithout frame and engine1550x465x620 mm775.0RUB 207,000Order
CNS 105-343105.0343.0 m160.0/30002493x465x845 mm1635.0465,000 rub.Order
CNS 105-392105.0392.0 m200.0/30002628x465x845 mm1786.0513,000 rub.Order
CNS 105-392105.0392.0 mwithout frame and engine1645x465x620 mm836.0220,000 rub.Order
CNS 105-441105.0441.0 mwithout frame and engine1740x500x620 mm897.0236,000 rub.Order
CNS 105-441105.0441.0 m250.0/30002768x500x891 mm1906.0RUB 599,000Order
CNS 105-490105.0490.0 m250.0/30002863x500x891 mm1971.0610,000 rub.Order
CNS 105-490105.0490.0 mwithout frame and engine1835x500x620 mm958.0248,000 rub.Order
CNS 180-85180.085.0 mwithout frame and engine1125x835x715 mm629.0RUB 187,900Order
CNS 180-85180.085.0 m75.0/15002310x835x990 mm1308.0RUB 305,000Order
CNS 180-128180.0128.0 m110.0/15002085x645x1000 mm1417.0RUB 379,000Order
CNS 180-128180.0128.0 mwithout frame and engine1230x645x715 mm737.0RUB 215,000Order
CNS 180-170180.0170.0 mwithout frame and engine1335x835x715 mm849.0RUR 229,000Order
CNS 180-170180.0170.0 m132.0/15002310x835x985 mm1611.0RUB 405,000Order
CNS 180-212180.0212.0 m160.0/15002445x835x985 mm1906.0480,000 rub.Order
CNS 180-212180.0212.0 mwithout frame and engine1440x835x715 mm966.0RUR 237,000Order
CNS 180-255180.0255.0 mwithout frame and engine1545x740x715 mm1155.0RUB 245,000Order
CNS 180-255180.0255.0 m200.0/15002555x740x930 mm2255.0530,000 rub.Order
CNS 180-297180.0297.0 m250.0/15003060x773x1010 mm2740.0670,000 rub.Order
CNS 180-297180.0297.0 mwithout frame and engine1650x773x715 mm1268.0RUR 255,000Order
CNS 180-340180.0340.0 mwithout frame and engine1755x773x715 mm1384.0RUB 269,000Order
CNS 180-340180.0340.0 m250.0/15003165x773x1010 mm2859.0680,000 rub.Order
CNS 180-383180.0383.0 m315.0/15003320x773x1010 mm3077.0760,000 rub.Order
CNS 180-383180.0383.0 mwithout frame and engine1860x773x715 mm1497.0RUR 285,500Order
CNS 180-425180.0425.0 mwithout frame and engine1965x773x715 mm1610.0RUB 307,000Order
CNS 180-425180.0425.0 m315.0/15003425x773x1010 mm3313.0780,000 rub.Order
CNS 300-120300.0120.0 m160.0/15002580x1050x1145 mm2600.0520,000 rub.Order
CNS 300-120300.0120.0 mwithout frame and engine1365x1050x830 mm1150.0270,000 rub.Order
CNS 300-180300.0180.0 mwithout frame and engine1485x970x830 mm1300.0300,000 rub.Order
CNS 300-180300.0180.0 m250.0/15002900x970x830 mm3000.0725,000 rub.Order
CNS 300-240300.0240.0 m315.0/15003065x970x1170 mm3243.0820,000 rub.Order
CNS 300-240300.0240.0 mwithout frame and engine1605x970x830 mm1460.0340,000 rub.Order
CNS 300-300300.0300.0 mwithout frame and engine1725x1370x830 mm1650.0RUB 387,000Order
CNS 300-300300.0300.0 m400.0/15003285x1370x1565 mm5250.0RUB 1,300,000Order
CNS 300-360300.0360.0 m500.0/15003200x1370x1565 mm5400.0Price on requestOrder
CNS 300-360300.0360.0 mwithout frame and engine1845x1370x830 mm1750.0430,000 rub.Order
CNS 300-420300.0420.0 mwithout frame and engine1965x1370x830 mm1950.0450,000 rub.Order
CNS 300-420300.0420.0 m500.0/15003405x1370x1565 mm6300.0RUR 1,645,000Order
CNS 300-480300.0480.0 m630.0/15002085x1370x830 mm6500.0RUB 1,765,000Order
CNS 300-480300.0480.0 mwithout frame and engine2085x1370x830 mm2150.0500,000 rub.Order
CNS 300-540300.0540.0 mwithout frame and engine2205x1470x830 mm2310.0RUB 537,000Order
CNS 300-540300.0540.0 m800.0/15003810x1470x1670 mm6660.0RUB 1,950,000Order
CNS 300-600300.0600.0 m800.0/15004175x1160x1440 mm6820.0RUB 1,954,500Order
CNS 300-600300.0600.0 mwithout frame and engine2325x1470x830 mm2470.0580,000 rub.Order

Multistage pump design - what does the unit consist of?

These types of pumps have a simple design. They consist of the following elements:

  • Housing made of corrosion-resistant materials;
  • Suction pipe that receives liquid;
  • Discharge pipe - through it water is supplied under pressure into the system;
  • Main shaft;
  • Impellers;
  • Bearings with self-lubricating function;
  • Seals at the ends of the device prevent water leaks from the working chamber.

The simple design of pumping equipment greatly facilitates its maintenance and troubleshooting. This helps save money on specialist services.

Operating principle of multistage pumps

A centrifugal multistage pump is a sectional device and operates in a specific order. First, the liquid enters the first section through the suction pipe, in which the impeller is located. After creating the necessary pressure, the water passes through the discharge pipe into the second section, where it is again affected by the centrifugal force generated by the second impeller. After this, the liquid under pressure flows from the pump into the outlet hose.

In other words, as each section of the pump passes, the fluid is exposed to greater pressure, which is created by the impellers. From this we can conclude that the pressure in a multistage pump is equal to the sum of all pressure indicators created in each individual section.

It is worth noting that with an increase in the diameter of the impeller and the speed of its rotation inside the unit, the pressure of the liquid leaving the pump will also increase.

Types of centrifugal pumps

Units can be classified according to the following distinctive features:

  • By number of steps:
  1. single-stage units;
  2. two-stage;
  3. multi-stage.
  • What is the number of fluid flows:
  1. single-threaded;
  2. with two streams;
  3. multithreaded.
  • By what principle is liquid supplied to the impeller?
  1. with spiral outlet;
  2. along an annular outlet, with a guide vane;
  • What is the design of the impeller:
  1. closed ;
  2. open impeller.
  • How the drive is made:
  1. using a coupling;
  2. through the gearbox.
  • By shaft location:
  1. vertical;
  2. horizontal.
  • Glandless rotor pump. In this case, the engine rotor moves directly the fluid. The engine stator, which is constantly under voltage, is separated from the rotor by a special sleeve, 0.1 to 0.3 millimeters thick, made of stainless steel. The rotor bearings are lubricated by a liquid medium, which also performs the function of cooling the rotor. The pump shaft is mainly horizontal.
  • Dry rotor pump. Here the motor rotor does not come into contact with the liquid medium that is being pumped. They usually have a large fluid supply.

Advantages and disadvantages of centrifugal pumps

Compared to other types, centrifugal pumps have advantages:

  • In a wide range of flows Q, fairly high values ​​of efficiency and pressure H are maintained, as a result of flat characteristics H = f(Q) and η = η (Q.
  • Increased rotation speed, which allows the pumps to be driven by electric motors and turbines.
  • The power change N has a smooth shape, which allows the pump to be started with the outlet valve closed or the check valve closed.
  • They have good stability in the operation of the devices and expansion of the technical values ​​of H and Q with parallel and series connection of pumps, when working on one pipeline.
  • Transient processes occur smoothly when operating modes of hydraulic systems change.
  • The pumps are located above the liquid level in the flow tank.
  • Due to various factors, the performance of pumps H, Q, η changes. These factors are:
  1. turning the diameters of impellers;
  2. change in rotation speed;
  3. change in frequency of power supply.
  • The low price of the pump, which is associated with the use of relatively inexpensive structural materials in the product:
  1. become;
  2. cast iron;
  3. polymer materials.
  • Easy to maintain and operate.
  • High reliability during operation.
  • Large fluid supply Q.
  • Liquid flows with small, uniform pressure pulsations.
  • They work successfully on “contaminated” liquids.

The disadvantages of centrifugal pumps are:

  • The unit must be primed before starting it up.
  • They have a tendency to cavitation.
  • Reduced efficiency when pumping viscous liquids.
  • Low efficiency value with small liquid supply Q.
  • It is better to use in the area of ​​large water supplies Q and low and medium pressures N.

Advice: You cannot use such devices without first filling them with water.

Types of multistage pumps - classification of market models

Modern multistage pumping equipment is divided into the following types:

  • Vertical units - pumps of this type are installed in a vertical position. Among the advantages of a vertical unit, one should highlight the generation of very high liquid pressure, the ability to pump liquid at a temperature of 100 °C and long service life without failures;
  • Horizontal multistage pumps are the optimal equipment for arranging water supply in a country house. The working planes of such a pump are performed in a horizontal position. This makes it possible to obtain water under high pressure with low device productivity.

Depending on the areas of application, the following units are distinguished on the market:

  • Industrial high-pressure pumps – have larger dimensions and higher power. Each industrial pump has a special coating that protects it from chemicals;
  • Household devices - these units have smaller dimensions and light weight. They are much easier to maintain and repair, they consume less electricity and make less noise. At the same time, they do not produce as high a pressure as equipment of the first type.

When buying a multi-stage unit, you must remember that industrial devices are characterized by fairly high electricity consumption. Because of this, it is better not to buy them even for servicing large farms. Instead, you can purchase two household pumps, which in total will consume much less energy than is required to operate one industrial unit.

How the pump works

Centrifugal forces act on the fluid so that it is directed towards the periphery of the wheel. In this area, through a ring-shaped channel (also called a snail), water is supplied to the pressure pipe (diffuser). And the purpose of this part is to convert some part of the dynamic energy into static energy.

A multistage pump is a newer unit, the design of which has a number of impellers and stages. These steps are located one after another. When choosing a centrifugal pump, you need to consider how the shaft is sealed. New models have a difference and this difference lies in the mechanical seal, while older models have a gland load. The first option maintains the tightness of the device and prevents leaks. If the pump operates with any vibrations or its shaft is not significantly displaced, this will not cause a leak.

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