Vertical pumps - model range and characteristics.

Vertical pumps, the design feature of which is the arrangement of the shaft and impeller corresponding to their name, are widely used both in everyday life and in various industries. Thanks to the vertical arrangement of the shaft, impeller and casing, the installation of this equipment does not require much space, which is one of the main reasons for its high popularity. Depending on the model, a vertical pump can be used as an autonomous mobile device, as well as an element of a water supply or wastewater system.

Industrial double-casing vertical pump designed for pumping clean or slightly contaminated liquids

Design and operational features

A characteristic feature of vertical pumps is a vertically located working shaft, due to which such equipment got its name. This arrangement is quite complex to implement, but it allows the pump to perform highly specialized tasks, in which it is significantly superior to its horizontal counterparts.

There are many types of pumps - drainage, slurry, water, cantilever, and can be made in both vertical and horizontal configurations. The use of vertical units is rational in case of limited working space, since their cylindrical body takes up minimal space. Their compactness makes vertical pumps widely used in shipbuilding and mechanical engineering, since they can easily fit inside the housings of large structures.

The second main area of operation of such equipment is pumping liquid from reservoirs and reservoirs. Thus, almost all water pumps - submersible, semi-submersible and drainage, are made in a vertical configuration. Semi-submersible pumps in a cylindrical casing often have the highest possible tightness class, since their drive can be located above the surface of the water, and the working element below its level.

Pipe mounted pump

The advantage of vertical type units is the ability to insert into pipelines. An example of such rationalization is a heat circulation pump, which is installed directly into an existing pipeline using flanges, without the need for additional connections and pipes.

However, the vertical arrangement of the working shaft also has a number of disadvantages, the main one of which is the complexity of the design in order to compensate for increased axial loads. For this, more powerful angular contact bearings are used, which, in turn, require changes to the standard lubrication system. In general, the overall efficiency of vertical units fully compensates for the above disadvantages.

Scope of application and classification

Vertical pumps are widely used in sewer and water supply systems for pumping liquids of any contaminant. The main areas of operation of such equipment are:

drainage systems;
heating and water supply;
mechanical engineering, machine tool building;
irrigation, reclamation and filtration systems;
sewerage and treatment complexes;
chemical industry.

The classification of vertical type units is carried out according to many factors, let’s consider the main ones:

Fluid supply power - low-pressure, medium- and high-pressure.
The speed of the working shaft is quiet, normal and high-speed.
Number of pumped flows - single-stage, multi-stage.
Type of working environment - for water, contaminated liquids, aggressive chemical substances, sewage waste.
Installation method: ground, submersible and semi-submersible.
Drive type: centrifugal, piston, screw.

Inline pump

The most common centrifugal-type units are in most cases represented by “inline” circulation equipment. Vertical pumps are installed directly into the pipeline through a flange connection. Semi-submersible units for tanks and tanks are also produced with such drives.

The centrifugal working mechanism consists of a blade wheel mounted on a working shaft. Such a wheel consists of two parallel disks connected by plate bridges. During operation, the blades are filled with water, which is pushed outward during rotation.

Depending on the number of bladed ears, circulation pumps are single-stage and multi-stage. Multi-stage units are capable of developing a much higher supply pressure, since the water in them sequentially passes through the cells of each of the wheels.

Centrifugal pump device

The operating cycle of piston pumps consists of alternating stages of suction and discharge produced by the movement of the cylinder-piston group. During the translational movement of the piston, a reduced pressure is created in the vacated cavity of the cylinder and water is sucked into it from the supply pipe. Next, the valve on the suction pipe closes, and on the supply pipe it opens, and the cylinder moving backwards pushes water out of the piston.

The key disadvantage of vertical piston pumps is uneven, pulsating flow, and less power than centrifugal units. However, piston equipment costs much less than centrifugal equipment, which is why such water and drainage pumps are widely used in household use.

How does a vertical slurry pump work? (video)

This is interesting: Cantilever pumps: device features, rules for selection and maintenance

Submersible and semi-submersible pumps

general description

The development of pumping equipment has led to the emergence of various types of pumping units capable of solving certain problems. One of these tasks is the need to pump out liquid from depth or from hard-to-reach places. As a rule, liquid is supplied to the pump unit through a pipeline, but in some cases the pump itself can be located in the volume of the pumped medium, which makes it possible to eliminate the suction part of the pipeline.

Based on the relative position of the pumped medium and pump parts, the following types are distinguished: surface, semi-submersible and submersible.

In the first case, the pumping unit is located above the level of the pumped liquid, and it is collected using a downpipe. Such pumps do not require additional sealing and are simpler to manufacture and design, however, the use of a suction pipeline is associated with a number of problems that greatly limit the use of surface pumps. Since it is advisable to use centrifugal pumps to pump large volumes of liquid, it is necessary to take measures to prevent cavitation - the process of formation of air bubbles in the liquid flow, the negative impact of which can lead to pump failure. Cavitation wear does not occur when pumping from a shallow depth, however, as the distance from the liquid surface to the impeller increases, this problem begins to become fundamental, which leads to the need to use a different type of pump or additional components, which increase the cost of the pumping unit. In addition, a number of cases require the pump to be mobile and able to quickly change jobs. A simple surface pump cannot always satisfy these types of requirements.

Within this classification, the opposite of surface pumps are submersible pumps. The working body and motor of such a pump are housed in a sealed housing, which can be placed directly into the pumped-out liquid. Thus, conditions are achieved under which the pump actually operates under filling and with a zero length of the suction pipe. Thus, in a submersible pump there is no need to take additional measures to prevent cavitation and protect against dry running. The consequence of this is that the depth from which it is necessary to pump out liquid is limited only by the amount of pressure that the pump can develop. Thanks to this, submersible pumps can be used in cases where surface pumps are inapplicable or ineffective.

Classification and principle of operation

Submersible pumps have the most complete classification according to areas of use. As a rule, each task places strict demands on the design and capabilities of pumping equipment, as a result of which the pumps of each group have a number of similar features. The following types of submersible pumps are distinguished:

well
drainage
fecal
borehole

Well submersible pumps are usually the simplest in comparison with other submersible pumps. This is due to the fact that they are designed to collect only clean water without large impurities. For this reason, well pumps do not sink to the bottom, but operate in a “suspended” state to prevent the ingress of bottom silt masses. They are used in cases where the water level is 8 meters below the surface, and under such conditions it is no longer possible to use a surface pump. The maximum depth of the water layer at which a well pump can be used is about 20 m.

Drainage pumps, unlike well pumps, are already capable of pumping contaminated liquid with solid inclusions such as silt, sand, etc. For this purpose, special grinders and screens can be installed on the pump to prevent excessively large solids from getting inside.

Sewage pumps are designed for more severe operating conditions compared to drainage pumps and must be able to pump viscous media with fairly large solids. They can also be equipped with grinders to handle highly contaminated liquids.

Borehole pumps, as their name suggests, are designed to pump water from wells. That is, they are used when pumping water from a significant depth is required. For rationality, wells are drilled with a small diameter and great depth. For this reason, well pumps have a cylindrical oblong shape, and are selected for the well so that the outer diameter of the pump is 1-2 cm less than the diameter of the well to prevent possible jamming. Since the level of the pumped liquid can be significantly below ground level, the well pump is required to create a significant pressure, as a result of which they are made multi-stage.

There are two types of well pumps: rod and rodless. Rodless pumps are typical submersible pumps with a combined motor and impellers in one sealed housing. In the case of rod borehole pumps, the motor is located outside the well, and the transmission of motion to the pump is carried out through a mechanical connection - a rod. Rod pumping units are most often used for oil production and have a remarkable appearance thanks to pumping machines that transmit movement to the rod.

According to the principle of operation, submersible pumps can be centrifugal, screw, vibration (diaphragm) and vortex. The use of one or another principle of pumping liquid is determined by a number of parameters set by the task assigned to the pump. Submersible pumps retain the advantages and disadvantages of the pump type whose pumping mechanism they use. Thus, vibration pumps are quite reliable, but have relatively lower flow and pressure. Screw-type submersible pumps are suitable for pumping viscous media and media that require gentle pumping. In cases where it is necessary to create significant pressure at a large flow rate of liquid, the submersible pump is made into a multistage centrifugal pump.

Design

A distinctive design feature of all submersible pumps is that the working body and the engine are combined in one housing. Since the pump is completely immersed in liquid in the operating position, its housing is sealed to prevent liquid from entering the motor. Power is supplied through a cable connected to the network already on the surface. The pressure pipe of a submersible pump can be connected either to a rigid pipe through a flange or to a flexible hose in the case when the liquid is not pumped out from a horizontal well or when the immersion depth varies.

In addition, a support cable can be attached to the submersible pump from the outside, supporting it in the operating position at a given depth. The use of a cable is resorted to in the case of a large weight of the pumping unit, when the strength of the power cable is not enough. The submersible pump can also be equipped with a float - a plastic hollow chamber connected to the pump with a special cord. The float serves as a level indicator and can drive the pump when the water level rises, and the float, floating, tensions the cable. Thus, a submersible pump can be set to maintain water at a given level by pumping out the excess.

The liquid suction point of submersible pumps can be additionally blocked with a protective mesh to prevent excessively large solids from entering the working body, which can lead to jamming or damage to the pump.

The internal structure of a submersible pump depends on its type. As an example, we can take the most common case of a centrifugal submersible pump. The electric motor rotor is located on a common shaft supported by bearings and the impeller is mounted in a cantilever. The shaft is sealed in the area between the wheel and the motor to prevent short circuits due to the pumped liquid entering the electric motor. The operating principle of a submersible pump is no different from the operating principle of a conventional pump of the same type.

Advantages and Benefits

Among the positive qualities of submersible pumps are the following:

Ability to pump liquid from great depths
Ability to pump out liquid from hard-to-reach places
Low noise operation
Additional cooling due to the surrounding liquid

The first two points are the defining advantages of submersible pumps over others. The specificity of problems of this type makes other pumps inapplicable for solving them, unlike submersible ones. Pumping liquids from great depths with surface pumps is either impossible due to insufficient self-priming force and the occurrence of cavitation, or is associated with excessive complication and increased cost of the surface pump. A submersible pump in this case has a key advantage, since it is much easier to create high pressure to lift liquid than to develop high suction force.

One should not lose sight of the efficiency with which submersible pumps can cope with pumping liquids from various pits, wells, basements and similar places. Due to their design, submersible pumps are mobile and can operate at any depth, the maximum value of which depends only on the pressure developed by the pump and the length of the power cable. The ability to work even with heavily polluted environments allows submersible pumps to pump out liquid from the bottom layer of various reservoirs or containers, where large amounts of silt or other types of sediment can accumulate.

Operating conditions where the pump body is located inside the fluid volume provide a number of additional advantages that improve some pump characteristics. In this way, the vibration created by the pump, and, consequently, the resulting noise, is partially absorbed by the liquid, as a result of which the overall noise of the pump decreases. A simple rule works: the deeper and in a larger volume of water the pump is located, the more noise will be absorbed by the environment during its operation. Another advantage of working in liquid volume is the additional cooling of the pump. This is due to the fact that the heat transfer rate in the pump/water system is much higher than in the pump/air system.

However, tailoring pumping equipment to solve such narrow problems irreversibly entails a number of disadvantages. Some of these shortcomings can be eliminated through the use of new technologies and materials, and the negative impact of the rest can be reduced to an acceptable level.

Application

Submersible pumps cover a fairly wide range of applications, including both domestic water supply and the mining industry. Well submersible pumps are usually used to supply water in places without a centralized water supply by drawing water from the depth of the well. If there are no aquifers at shallow depths, but it is possible to take artesian water from a well, then more complex well pumps are used. The complexity is determined by the need to draw water from a considerable depth (more than 100 m).

Well and borehole pumps also find their use in the mining industry. They are used for pumping groundwater from wells and mines. In addition, with the help of downhole pumps, rare earth metals can be extracted by the leaching method, in which valuable ore components are transferred to a dissolved state using special solutions, and then they are pumped out and the target metal is extracted.

Drainage and sewage pumps, capable of pumping out liquid from bottom layers, where the concentration of various types of solid inclusions is high, are also used to solve a wide range of problems. In everyday life, they are used to pump out water from swimming pools or flooded basements, and using pumps with a grinder, it is possible to pump out water from drainage pits and reservoirs. Drainage pumps are used for similar tasks during natural disasters and accidents when drainage of flooded areas is required.

In the field of water disposal and sewerage, fecal pumps are also widespread. They are successfully used both in the sewer system of a country house and at sewer pumping stations, where the flow rate is disproportionately higher. The advantage of drainage and sewage pumps in this case is also the ability to pump out heavily contaminated water from great depths.

How are centrifugal pumps classified?

Centrifugal vertical pumps and all centrifugal products are classified according to:

The number of wheels they come in is:

single-stage with one wheel, which can be cantilever;
multi-stage, with a large number of wheels.

Pressure is distinguished:

with low pressure up to 2 kgf/cm2;
with an average pressure from 2 to 6 kgf/cm2;
with high pressure, which is more than 6 kgf/cm2.

Method of supplying water to the impeller. The water supply to the impeller can be:

with one-way liquid inlet;
double suction, when water is supplied from both sides.

Shaft location. Centrifugal pumps are:

horizontal;
vertical.

Housing connector. The housing connector is:

horizontal;
vertical.

The method of draining liquid from the impeller into the spiral channel of the pump housing:

spiral centrifugal pumps, in which the liquid is discharged directly into a spiral channel;
turbine Here, before entering the spiral channel, the liquid must pass through a special device, which is a guide apparatus consisting of a stationary wheel with blades.

Impeller rotation speed levels:

slow-moving;
with normal rotation speed;
high-speed devices.

Type of liquid pumped by the pump:

plumbing;
sewer;
alkaline and acidic;
dredgers;
oil and others.

Method of connection to the motor:

driven, with a pulley or gearbox;
connection via a coupling.

The kit with centrifugal pumps should include:

A receiving check valve with a mesh, which is necessary to retain water in the pump suction pipe and housing when filling it before starting, and the mesh should retain large suspensions floating in the water.
Valve.
A vacuum gauge used to measure the vacuum on the suction side. The device is placed on a water pipe between the valve and:

device body;
a tap through which air is released during filling is placed in the upper part of the body;
on the pressure pipeline with a check valve that prevents water from entering through the pump when another pump is operating in parallel, in the opposite direction.

A valve on the pressure pipeline, which is necessary for starting, stopping and adjusting the pressure and productivity of a centrifugal pump.
A pressure gauge for measuring the pressure on the pressure pipe, which is developed by the pump.
The safety valve, located behind the valve on the pressure valve, serves to protect the pressure pipe, pipeline and the pump itself from water hammer.
Device for filling the pump with water.

Tip: When purchasing a centrifugal pump, you need to make sure that all components are available, according to the attached operating instructions, and check the serviceability of the device.

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.

Classification

Vertical multistage centrifugal pumps are divided into different subgroups, depending on the following factors:

Multistage vertical pumps

In multistage centrifugal vertical pumps, the pumped liquid sequentially passes through all sections of the device before entering the pressure pipe, which makes it possible to significantly increase the pressure of the working medium at the outlet. Depending on the model, pumps of this type may contain in their design a different number of impellers (from 2 to 10), which are fixed on one shaft, but are located in separate modules each.

Vertical multistage pump design

The modules of a multistage vertical pump are placed in one casing, which is installed between the suction and pressure chambers of the device. All elements of the body of a multistage electric pump, the nozzles of which are located in the same horizontal plane, are tightened with pins, and the joints between them are sealed using sealing elements.

As mentioned above, multistage centrifugal pumps, due to their design features, can significantly increase the pressure of the pumped liquid medium at the outlet. The pressure of the fluid flow created by a multistage pump is the sum of the pressure values generated by each of its stages.

A little history

The simplest pumps have been known since before our era. But the idea of using centrifugal force in the process of pumping water appeared to Leonardo da Vinci at the turn of the 15th-16th centuries, but only in sketches. It is not known for certain when exactly a full-fledged centrifugal pump was developed, so no one can name a single inventor.

At the beginning of the 17th century, the Frenchman Blancano built the simplest possible installation that could supply water using a rotating impeller. A centrifugal pump with a four-blade impeller located in a volute casing was first proposed by the Frenchman Denis Papin at the end of the 17th century. The first vertical centrifugal pump design was tested and introduced by engineer Le Demur in the first half of the 18th century, and the classic wheel shape appeared only at the beginning of the 19th century. Centrifugal pumps became widely used after they began to be equipped with an electric motor.

Russian and foreign inventors have been working independently on the creation of full-fledged units for decades.

The design of a vertical pump with several stages appeared at the turn of the 19th-20th century thanks to our compatriot, the Russian engineer Pushechnikov. His pumping unit could pump water from wells up to 250 meters deep.

Correct operation is the key to long service life

Failure-free operation of centrifugal pumps can be ensured by organizing the required operating conditions for the equipment and installing monitoring devices. A valve and an appropriate filter will help protect the impellers from foreign bodies. A check valve with a pressure gauge that determines the pressure at the inlet pipe will help avoid the occurrence of cavitation processes.

A pressure gauge that records the pressure inside the pump will help prevent water hammer.

When choosing vertical centrifugal units, you should focus on their characteristics. The most important parameters are:

power consumption;
performance;
water jet pressure at the outlet;
external dimensions;
material for the manufacture of the flow part and working parts that come into contact with the pumped liquid.

The lifespan of pumping equipment largely depends on its correct use. Vertical pumps should not be installed in an inclined position, much less in a horizontal position. They are strictly not allowed to be used for pumping media not specified in the instructions. The water pump will not withstand the action of aggressive or viscous liquid; it must not be installed in drainage systems where solid particles may be present. But it makes no sense to purchase expensive chemical pumps for watering your garden.

If pumping equipment is used in winter, it will need to be insulated or installed in a heated room. Otherwise, the housing may depressurize and even burst.

Compliance with operating rules will help prolong the full operation of any centrifugal pumps, including vertical ones.

This is interesting: Centrifugal pumps: design, principle of operation, advantages and disadvantages

Purpose and scope of application of vertical pumps

Given their popularity, it is important to know in what cases and for what purpose centrifugal pumps should be used. A vertical centrifugal pump can be used not only as a stand-alone pump, but also as part of a large interconnected water supply or wastewater system.

This kind of pumping devices are usually used in water supply and sewerage systems for pumping both clean, clogged, and even aggressive media with a low degree of viscosity. Users always note their compactness, ease of maintenance, high efficiency and, best of all, they have lower noise levels than other submersible stations.

Taking into account all of the above advantages, a single-stage centrifugal pump, and, if necessary, a multi-stage pump, is widely used for various purposes, the main of which are:

supply or drainage of water;
heating of premises;
drainage;
filtration or reclamation;
cleaning and much more.

Vertical pump on an industrial pipeline
But still, most often they are used as water pumps.

In the USA, at most chemical plants under construction, centrifugal single-stage high-speed pumps are installed, which are produced by the well-known company Sundstrand Corporation, founded in 1926.

Vertical pumps easily combine two important criteria: ease of maintenance and installation costs. It is important to note the fact that these units work perfectly with high and low pressure supplies and flawlessly guarantee more than 46 thousand hours of continuous and error-free service.

Classification of vertical pumps

Centrifugal pumps can be sorted according to many criteria. For example, if we take into account the pressure, then they come with a low, medium or high level. If we take into account the degree of pressure, it can be low (up to 0.2 MPa), medium (from 0.2 to 0.6 MPa) or high (more than 0.6 MPa). Depending on the location of the wheel axle in space, there are horizontal and vertical ones.

Also a distinctive feature is the connection option with an electric motor, namely with a direct drive, gear mount or with a pulley. The method of draining liquid from the impeller into the housing channel in the diaphragm can be spiral or bladed. But most often they are distinguished by the method of immersion: land-based, semi-submersible or submersible.

Today, the vertical slurry pump is incredibly popular. This pump has a wide range of design features, since a cantilever shaft with a bearing housing and a drive, which is located on the top of the tank, rotates the impeller from inside the diaphragm housing itself. All pump sizes can be configured with a range of column lengths and impeller designs. Ideal for aggressive and coarse particles of high concentrations of cellulose slag and widely used in the metallurgical, mining and coal industries.

According to Klint Bawden, development manager at Swedish pump manufacturer ITT Water & Wastewater, the market trend is moving away from vertical spindle diaphragms towards submersible slurry pumps. “This is because these pumps are more convenient, require less infrastructure, are quieter in operation and are more efficient than vertical spindle diaphragms.”

Vertical centrifugal pump Wilo HELIX VE 1012-2/25/V/KS

He points out that because submersible pumps operate directly in slurry, they require no support structure and take up less space. In addition, the motor and body volutes are an integrated unit, making it compact and easy to install. Another important advantage is that, when working underwater, the noise level is automatically reduced and, in some cases, silent operation is guaranteed.

As Klint says: “Add to this the Victaulic flange and coupling of the Flygt 5100/5150 series pumps for quick and easy connection to all models of commonly available fittings and you have a versatile VSP.”

Advantages and disadvantages of centrifugal pumps

Both multistage and single-stage pumps have a number of advantages that make these devices so popular among consumers. The advantages of the hydraulic machines under consideration include:

compact dimensions and light weight (since the operating shaft of the pumping equipment is directly connected to the drive motor, which eliminates the need to use additional transmission mechanisms);
high reliability and long service life, no need for regular maintenance;
minimizing the risk of pressure surges (the liquid medium pumped by pumps of this type is supplied to the pressure line in a smooth mode);
absence of valve elements (this makes it possible to pump contaminated liquid media containing insoluble solids);
simplicity of design (this is why any multi-stage or single-stage pump is affordable).

The simplicity of the design of centrifugal pumps ensures their maintainability, modernization and re-equipment

Among the disadvantages of single- and multistage pumps are:

rather low efficiency when operating in low-capacity mode (this becomes a problem when it is necessary to pump a small volume of liquid medium under high pressure);
impossibility of quick start-up (for such devices to start working, their working chamber must first be filled with liquid).

Parameters and varieties

Pumps with a vertical shaft and impeller arrangement, belonging to centrifugal type devices, are classified according to the following characteristics:

pressure (depending on the value of this parameter, vertical pumps can be with low, medium or high pressure levels);
operating speed (based on this characteristic, normal, low-speed or high-speed hydraulic machines are distinguished);
volume of working medium pumped per unit of time (device performance);
the number of steps, which can be sections or rings of equipment;
the number of lines through which the pumped medium enters the device (one- or two-way devices);
the type of liquid medium for which the pump is intended to pump (drainage, fecal, chemical, water, etc. electric pumps);
the location of the device relative to the medium it pumps (ground models, submersible and vertical semi-submersible pumps);
method of connection with the drive electric motor (direct drive, gear and pulley hydraulic machines).

Vertical centrifugal pumps with normal suction for baseplate mounting

Vertical pumps are successfully used for pumping clean, contaminated and chemically aggressive liquid media characterized by a low degree of viscosity. The most significant advantages of hydraulic machines of this type include:

compactness;
ease of use and maintenance;
high efficiency;
low level of noise generated during operation.

Due to the above advantages, vertical multistage centrifugal pumps (as well as single-stage ones) are actively used to equip the following systems:

autonomous water supply;
heating;
drainage and purification of liquid media;
condensation;
filtration, irrigation and reclamation.

Vertical pumps at a water intake station

A vertical centrifugal pump, which raises the fluid it pumps to a higher level by increasing the pressure of its flow, can fall into one of the following categories:

hydraulic machine of surface or ground type;
semi-submersible pump;
submersible type device.

Both surface models and semi-submersible and submersible pumps are equipped with an electric motor, which ensures the rotation of the impellers of such devices.

Surface pumps of the vertical type, as their name implies, are installed on the surface of the earth, in close proximity to the reservoir from which the liquid must be pumped out. The place for installing such equipment can be a pit or a specially prepared area that does not come into contact with the surface of the pumped liquid medium. A semi-submersible vertical pump, as also follows from its name, is only partially lowered into the pumped liquid medium, while the drive motor remains above the surface of the liquid.

Semi-submersible vertical chemical pump

During operation, the housing of submersible pumps is completely located in the thickness of the pumped liquid medium. If a vertical semi-submersible pump cannot be installed in wells whose shafts are characterized by a curved shape, then a submersible type device has this capability.

It should be borne in mind that vertical type electric pumps cannot be started until the inside of their housing is filled with liquid. If this requirement is neglected, the pump will run at idle speed, which can lead to overheating and, accordingly, premature failure.

Multistage centrifugal pumps of the vertical type are distinguished by higher power, which are able to significantly increase the pressure of the flow of the pumped liquid medium, which cannot be said about single-stage models. At the same time, the power and efficiency of multistage vertical type pumps are higher, the more sections there are in the design of such devices. Each of the sections connected to each other in series contributes to an increase in the kinetic energy of the flow of the pumped liquid medium.

Operating principle

The main design element of a vertical centrifugal pump is an impeller equipped with blades. In vertical multistage pumps, there are several such wheels mounted on the shaft, which makes it possible to increase the efficiency of using this equipment. The impellers of these centrifugal electric pumps are two disks mounted on a vertical shaft, which are located at a certain distance from each other and are connected by blades that bend in the direction opposite to the direction of rotation of the wheel itself.

Vertical centrifugal pump design

The principle by which a vertical centrifugal pump operates is as follows:

When the wheel rotates in a temporary working chamber formed by two nearby blades, a vacuum of air is created, which facilitates the absorption of liquid into it through the inlet pipe.
After the liquid enters the temporary working chamber and begins to rotate along with the blades moving it, a centrifugal force begins to act on it, pressing it against the walls of the inner chamber.
When liquid enters the area of the outlet pipe, already under pressure due to the centrifugal forces acting on it, it is pushed into the pressure line.

Design of a vertical semi-submersible pump with a spiral outlet

When the impeller of a centrifugal electric pump with blades attached to it rotates, the suction of the pumped liquid and its expulsion into the pressure line occurs in a continuous mode. Thus, during one rotation of the wheel, several cycles of suction and expulsion of the pumped liquid occur.

The electric pump shaft, on which its impeller is mounted, is placed in bearing units to ensure ease and accuracy of rotation, and gland-type sealing elements are installed between the moving and stationary parts of the device.

Certain models of vertical submersible pumps can even be installed in pipelines of the appropriate diameter, which can significantly increase the efficiency of pumping liquid media. The suction and pressure pipes of such models are located on the same axis.

Vertical shaft units

Two brands of single-stage devices for clean 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 absorbs axial forces. The pump seal is equipped with a hydraulic seal with soft padding. Type NV units are directly connected to electric motors or by means of solid seam couplings via an intermediate shaft. The single-stage vertical centrifugal pump has a capacity from 3240 to 10,800 cubic meters per hour and a head from 29 to 40 meters.

Pumps of the NF, NFuV and FV brands. Open and diagonal devices

The following standard sizes of installations are provided: 2NF, 4NF, 6NF, 8NF. Their productivity ranges from 36 to 864 cubic liters per hour with a pressure of 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.

To work with wastewater, a single-stage diagonal-type centrifugal pump is often used. The impeller in these units, as well as in models of the FV and NFuV brands, is equipped with two blades. Their productivity varies from 43 to 150 cubic meters per hour, and the pressure reaches 63 m.

Dredgers

Dredgers are used to pump mixtures of loosened soil and liquid through pipes to the required distance. Today, the market produces pumps with a transportation range of up to 5 km and a capacity of 40 to 1200 cubic meters per hour. With the help of dredgers, it is possible to develop excavations up to 15 m deep below the water horizon. These installations have a number of features due to the high concentration of large particles in the pumped water mass. For this reason, a wear-resistant wheel is created from manganese hard steel.

The single-stage vertical centrifugal pump is protected by armor on the inside of the housing to prevent rapid wear. To prevent the mechanism from becoming unusable so quickly, purified water is supplied between the wheel into the left cavity and to the oil seal through special drillings to flush out solid fragments from these places.

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