Drainage pump with level measurement system. We select and connect a drainage pump: recommendations from experts. Pump selection according to technical characteristics

Drainage pumps

In the "Pumps" section, we will consider another type of pumps used in bits and industry - these are submersible drainage pumps. Drainage submersible pumps are used for pumping clean or slightly polluted water from cellars, pits, reservoirs and wells, for automatic emptying of pits and shafts, for keeping flooded buildings and basements dry, for lowering the water level, if polluted water cannot be discharged under natural slope into the sewer. The pumps are also used for pumping slightly polluted, rain and wash water. Drainage pumps are not used for pumping water containing coarse impurities such as sand, fibers or faeces, nor are they used in explosive environments. These pumps can be mounted both stationary and in a mobile, portable version.

Technical characteristics and arrangement of drainage pumps

Operating characteristics

• The temperature of the pumped medium is not more than 35°С
• Submersion depth of the pump is not more than 5 m
• Maximum solids diameter Ø 5 – Ø 35 mm depending on the model
• Minimum liquid level, 15 - 70 mm depending on the model

Engine

• With built-in thermal overload protection
• With built-in capacitor
• Insulation class F
• Protection class IP 68

materials

• Pump handle plastic or stainless steel depending on the model
• Pump housing plastic, cast iron or stainless steel depending on the model
• Impeller Noryl polymer or stainless steel depending on the model
• Motor housing plastic, cast iron or stainless steel depending on the model
• Rotor shaft stainless steel
• Double mechanical seal with oil chamber

The housing of the drainage submersible pump, depending on the model, can be made of plastic, cast iron or stainless steel. The electric motor is hermetically sealed from the ingress of the pumped medium into it. Depending on the model, the drain pump motor may be oil-filled. The pump shaft has a mechanical seal to isolate the oil chamber from water. The engine is cooled by the pumped medium in which the pump is located.

Installation and connection of pumps

The pump is mounted at the bottom of a pit, pit, tank or cesspool. The pumped medium enters the sewer through a hose or permanently through an installed pipe. As a rule, the drainage pump operates in automatic mode, since it is equipped with a switch that turns on the pump at a certain water level “h” (Fig. 1) and turns it off at a minimum water level “h1”.

Drainage pumps should not operate without liquid, this mode of operation leads to overheating and destruction of the mechanical seal between the pump and the motor. It is necessary to adjust the float shutdown of the pump in such a way as to maintain the minimum water level “h1”, depending on the model and brand of equipment. The passport indicates the minimum water level. When installing submersible drainage pumps, pay attention to the following:

• The installation site of the drain pump (pos. 1) as well as the tank or well itself must be protected from frost.
• When installing the pump permanently, the bottom of the shaft or pit must be flat and free of large objects and dirt, such as construction debris, bricks and earth.
• The diameter of the pressure line (pos. 2) or hose must not be smaller than the diameter of the pump's discharge port. To avoid pressure loss, it is recommended to select a pipeline or hose with a larger diameter than the pump discharge port.
• In order to protect against a possible reverse flow of the pumped medium from the sewer pipe, it is necessary to install a valve (item 4) and a valve (item 5) on the pressure pipe for protection during stationary installation.
• When installing the pump in a portable version, lay the discharge pipe or hose in the form of a loop above the maximum sewage level for the area (usually this is ground level).
• The threaded connections of the pipeline must be sealed with tow or fum tape.
• When installing the drain pump, care must be taken to prevent it from being disconnected from the discharge pipe and to install it to prevent suction of silt or sand.
• The pump must be installed in such a way that it can be completely submerged in the pumped medium. Adjustment of the level of turning on and off the pump can be changed by changing the length of the float switch cord (Fig. 1).

It is strictly forbidden to carry, raise or lower, and even more so to hang the pump by the power cable or float attached to the pump. A rope or chain must be used to lower or raise and to secure the drain pump.

To ensure free movement of the float switch, the minimum dimensions of the well or pit for the drainage pump should be length - width - height 40x40x50 cm. Alternatively, concrete well rings with an internal diameter of 40 cm can be used.

Electrical connection drainage pumps

The electrical connection of the drain pumps must be carried out by a qualified electrician in accordance with the Electrical Code (EEC) and in accordance with local requirements, codes and standards. While doing electrical connections you need to pay attention to the following:

• The mains voltage must match the voltage indicated on the nameplate of the pump.
• The drain pump must be connected to the power supply using a socket with a ground wire powered through the equipment (RCD) with a rated leakage current of 30 mA. The socket must be mounted in a dry room and in a place inaccessible to water.
• The single-phase asynchronous AC motor has a built-in thermal protection that turns off the pump when the motor is overloaded and automatically turns it on after it cools down.

The electrical connection diagram of the drain pump is shown in fig. 2.

Commissioning of drainage submersible pumps

The float switch must be free to move. The switch must turn off the pump before the suction screen of the pump draws in air. After filling the well / pit and opening a tap or gate valve on the discharge pipe, the pump automatically turns on when the switch-on level “h” is reached, and turns off when the switch-off level “h1” is reached (Fig. 1). The submersible drainage pump must not run dry (without water). Adjustment of the on and off level of the float switch The level of off / on of the drainage pump can be adjusted by changing the length of the arm of the float switch, fixing it with a special bracket on the pump handle using a cable. Waste water entering the well or pit must not fall on the intake screen of the pump. The air present in the incoming water can enter the working chamber of the pump and air it. The maximum volume of sewage entering the well / pit should not exceed the pump capacity. During the first start-up, it is necessary to make sure that the drainage pump has time to pump out the incoming volume of water.

Operation, maintenance and repair of drainage submersible pumps

Usually, submersible drainage pumps during operation, does not require special maintenance. In order to avoid jamming of the pump impeller due to long periods of inactivity, it is necessary to regularly (every 2 - 3 months) check the operation of the pump and the float switch. To do this, turn on the pump for a short time by forcibly raising the float switch. During operation, every 3 months it is necessary to clean the walls and bottom of the well or pit from dirt and sand. It is also necessary to flush the pump housing and the intake grate, and if necessary, remove and clean the grate, and then reinstall it in its original position.

During the operation of the drainage pumps, measures must be taken to ensure that the immersion depth of the pump does not exceed the mark indicated on the pump housing. If this value is exceeded, there is an increase in the load on the gland seal. It is also necessary to monitor the presence of sand in the pumped water. Due to the increased content of sand or suspension in the water, the shaft seals and seals wear out. Damage to the mechanical seal causes oil from the oil chamber to enter the water. And the chamber itself is filled with water. Then the process is even more aggravated, water begins to enter the drain pump motor. If there is a protective shutdown device for the equipment, the pump will be disconnected from the mains. If the RCD is not installed, the engine will safely “burn out”. The cost of repairs will increase dramatically, since in addition to simply replacing the stuffing box rings and oil, rewinding the motor stator will also be added. Repair and maintenance of this equipment should be carried out only in specialized service centers.

Water can enter the motor through cable glands or damaged cable insulation. This usually occurs when a mechanical load is applied to the power cable. Therefore, when installing the equipment, the cable must be attached with cable clamps to the pressure pipeline with sagging. Therefore, once again, it is strictly forbidden to lower or raise the drainage pumps using the power cable.

If the drain pump is used as a portable one, then after each use it is necessary to wash the pump and the float with a jet clean water. Store the equipment in a dry and ventilated area.

Thank you for your attention.

Drainage pumps are quite widely used in agriculture, manufacturing and construction. They are indispensable helpers in everyday life and for that category of people who thought badly when choosing a site for the construction of a house or a summer residence. With their help, it is possible to effectively pump out water when the lower rooms are flooded - this to some extent will increase the service life of the structures.

The main area of ​​application of drainage pumps is the pumping of heavily polluted water, sometimes containing large particles of dirt, from various containers: trenches, pits, basements, cellars, pools.

Rice. 1 Drain pump design

Structurally, the drainer is made in a plastic or metal case, which houses its main components. An impeller with a spiral impeller is fixed on the motor shaft, the electric motor itself is placed in a separate metal case. At the bottom of the housing there is a grate through which the liquid is sucked in. The perforated holes in it are designed for the maximum allowable particle diameter with which the device can work.

All models of submersible drains are equipped with a float switch that opens the power supply circuit of the electric motor, if the water level is low, the device drops and the ball inside its structure falls down onto the lever, which opens the contacts.

The float switch performs not only the functions of protecting the engine, but also organizes automatic operation, monitoring the water level and turning off the drain pump when the minimum value is reached and turning it on again when filling.

When power is applied to the pump motor, its impeller sets in motion and begins to suck in water through a small hole in the device body in the center of its axis. Under the action of centrifugal force, the incoming water is pushed out through the outlet pipe located on the side of the drainage pump housing.

Main characteristics of drainage pumps

Power consumption. The main parameter of the device, responsible for its performance and efficiency.

The size of the filtered particles. Submersible drainage pumps for water are designed to work in different environments, so the specification usually indicates the particle size in the working environment in millimeters, which does not cause clogging of the filter and the installation of work.

Maximum pressure. The pressure is understood as the pressure (specific energy) created by the pump for pumping water, for ease of understanding, it is given in meters.

Maximum water temperature. The operation of the drainer in a high temperature environment contributes to overheating of its engine, which is unacceptable, since the engine cases are designed for water cooling in the working environment.

Immersion depth. The maximum distance that the drainage pump can be put into the water intake source for its uninterrupted operation.

Performance. The capacity of the pump, indicating the amount of liquid raised per unit of time (measured in cubic meters or liters per hour).

Types of drainage pumps

Like all other similar devices, drainage, depending on the installation site, are divided into two types: surface and submersible.

Surface drainage pumps

They are placed on the surface of the earth near the place of water intake, a suction pipe is installed on the bottom of the tank with the pumped liquid. The float mechanism necessary for the operation of the drainer is fixed at a small height from the bottom and automatically turns the device on and off when the liquid level in the tank changes.

Surface devices are easy to maintain, have good mobility and the main disadvantage: a small suction depth.

Submersible drainage pumps

The body of the device is placed directly in the tank with the liquid being pumped out, usually it is installed on the bottom, using a small stand to prevent sludge from being sucked in. Water enters the housing through the filter in its bottom, the float sets the operating mode.

Compared with surface types, the submersible drainage pump has the best performance: capable of pumping water from great depths, its performance and power are greater.

Drain pump models

For comparison, we present the characteristics of the most common models of submersible type drains (external ones are practically not used in everyday life).

Prorab 8720 PP is a good option for those who do not know which drainage pump to choose - the model has an excellent price-quality ratio.

Peculiarities

• installation depth: 5 m;
• head: maximum 8 m;
• pumping volume: 13 cu. m/hour;
• power: 750 W.;
• particle filter: 35 mm;
• control: float.

Gileks Kachok 550/14 is a fairly powerful submersible type drainage pump with a vertical installation from a domestic manufacturer for pumping large volumes of water.

Rice. 5 Gileks Kachok 550/14

Peculiarities

• installation depth: 8 m;
• head: maximum 14 m;
• pumping volume: 33 cu. m/hour;
• power consumption: 2000 W;
• particle filter: 40 mm.;
• operating temperature: up to 35 C;
• cord: length 10 m;
• control: float.

When choosing a drainage pump for pumping water, you should take into account the parameters of the object for work. External views are more practical to use with small volumes of pumped liquid from shallow depths - in this case, they have small overall dimensions, they are easier to install and move. For large volumes of pumping and long-term operation, submersible type domestic drainage pumps are better suited.

Most often, the purchase of such specific equipment as a drainage pump is associated with an urgent problem of pumping water, for example, from a basement or in a suburban area. In the best case, a suitable drainage unit can be rented from friends or neighbors, at worst, the pump is bought “by ear”, on the advice of product sellers or from superficial information available on the network. Often, a "drainer" is acquired in a hurry, based on momentary tasks and cash, although one could show a little patience and buy a truly versatile and useful unit.

What kind of "beast" and what are drainage pumps for

From the name itself - an electric pump for drainage work, it is clear that this is a device that allows you to relatively quickly remove or pump out water or liquid from pits, pits, sewers, any basements or basements, wells, pits and simply water collection tanks.

But in practice, you can use a drainage pump to solve a wider range of problems:

• Very suitable for irrigation and irrigation systems, beds, lawns, any vegetation on the site where the power and water pressure of a fire hydrant is not required. In this case, drainage pumps for sewerage successfully use the rainwater collected in the storage tank;
• It can be used for technological pumping of water from a collection tank at a car wash, for cleaning and washing asphalt or concrete paths around the house;
• Suitable for sewerage in a private house, washing and disinfection of objects such as a sewer communication complex of a septic tank;
• Using a drain pump, you can easily fill and pump out water from the pool, wash it and even put out a small fire.

Important! By design and purpose, the drainage pump for sewage is not a copy of the fecal pump, there are slight differences between these two units that fundamentally affect their functions and performance in certain environments.

How does a drainage pump work and how does it work?

Both units, the submersible drainage pump and the fecal pump unit, are built according to the scheme using a centrifugal paddle wheel mounted on the motor shaft. The used principle of centrifugal spinning of the liquid in the body makes it possible to do without valves in the design, which makes it possible to work even with dirty water and a large amount of sand. Trying to use normal submersible pump in this case, it will very quickly lead to the "burnout" of the valve system and the failure of the entire unit.

The electric drive with a power cord is packed in a sealed case with an external protective casing made of plastic, stainless steel or even cast iron.

The main difference between devices for drainage works and pumping out fecal waters or masses is in the design of the centrifugal wheel, the shape and location of the blades, the configuration of the volute of the pumping unit.

Important! The fecal pump is always inferior to the drainage unit in terms of pressure, efficiency and performance. But at the same time, it is more versatile and less whimsical to working conditions.

Such a device will be able to pump out water contaminated with clay, plant residues, dense and viscous concretions without damage to the impeller of the unit. Some models of the drainage pump can work with dirty water containing a suspension of sand or silt, but up to certain concentrations.

In both cases, drainage and fecal pumping units are designed in the form of vertical housings with a crate at the bottom of the device. The unit is immersed on a suspension cable or cord into the liquid to a certain depth and fixed. In the upper or side wall of the pump unit there is a branch pipe for connecting the outlet hose. The pumping device is controlled by float sensors or internal liquid level sensors.

What to look for when choosing a drainage pump

There are a large number of models of drainage pumps. Sometimes drainage systems include surface centrifugal pumps, to which you can connect a pipe or a rigid plastic suction hose immersed in the pumped liquid. These models are not sealed and are not intended to be immersed in water or sewage. They are less versatile, but at the same time they have great power and performance. Such designs are usually used for stationary drainage systems, performing continuous pumping of water from relatively uncontaminated and clean containers.

Selecting the parameters of the drain pump

Before you decide on a particular model of drainage pump, you need to answer a few basic questions. But the main condition is to decide why and for what purposes it is planned to purchase a pumping unit. Based on this, you can focus on the following characteristics of the pump:

1. Immersion depth of the pump unit. This is the first of the main criteria. It determines the maximum depth from which water can be pumped out and thrown into or out of the site. If the length of the horizontal section of the outlet hose is more than 5 m, the maximum working depth will have to be reduced, based on the following proportions: - for every ten horizontal meters of the laid hose, the maximum working depth should be reduced by one meter;
2. The quality of hull materials, waterproofing, protective coating metal parts, power cord, suspension system, float mechanism, sealing rubber bushings and couplings;
3. Availability of protective devices, such as a thermal relay or a load cell. It is advisable to choose a drainage pump with automatic engine on and off when a certain liquid level is reached. Almost all models are equipped with a float sensor that allows the unit to turn on when the water level rises above the critical one;
4. Unit performance. The indicator is important, but most often they pay attention to it last, unless, of course, you need to pump out several tens of cubic meters of water daily. In addition, the performance of the pump significantly depends on the depth of immersion, so it is chosen with a margin of 30-40%.

Important! Manufacturers actually deceive buyers of drainage pumps, indicating both the maximum depth and maximum performance. In fact, the declared performance, for example, 5 cubic meters per hour according to the passport, is achieved only on the surface. At a maximum depth of 5 meters, the performance of the pumping unit will be a maximum of several hundred liters per hour.

In addition to the above criteria, when choosing, pay attention to the weight of the drainage pump and the material of the housing. Firstly, the large weight of the unit drastically reduces the convenience of working with it, and secondly, there are cases when, when lifting the pumping device after pumping out water, it was dropped onto a solid base from a decent height of several meters. Aluminum and cast-iron cases split, thin-walled steel ones deformed, plastic ones got off with light scratches. But in an abrasive environment, with a large amount of fine gravel, slag, sand, a cast iron body has the best resistance.

If you need to pump out water from a tank or a well with cluttered branches and debris, pay attention to a drain pump without a float with an electronic water level sensor. But first study the instructions and characteristics of the selected model. For the normal operation of such a unit, it is necessary to correctly manually adjust the sensor that will control the operation of the pump. In some cases, the manufacturer generally refuses the float system, providing the ability to control the operation of the motor manually.

Most of the units operate freely on water with microparticles up to 0-3 mm, in some cases the models can be modified to increase the linear size of microparticles up to 10 mm, but their content should not exceed 10%.

Features of the device drainage pumps

Each model of the drainage pump has its own specifics, its own advantages and disadvantages.

For example, the minimum depth from which the drainage pump is able to pump water. Usually, such problems are much more difficult to solve than pumping water from a well at a water level height of several tens or hundreds of centimeters. Most often, this situation occurs when a basement or yard is flooded, during early spring or after a monthly rainfall. The standard minimum water level from which a “drainer” can collect water, for example, from a cement basement floor, is 5 cm, drainage units for dirty water and fecal pumps can work from layers of 7-8 cm. But some models of the Danish company Grundfos » able to work with a layer of clean water up to 1 cm.

Maximum immersion depth of the unit. Oddly enough, but high pressure only improves the operating conditions of the pump. When water is removed in the form of a thin layer of liquid, part-load operation may occur, threatening to overheat the motor, while at depth there is no such problem. It is clear that models with a steel case are cooled much better than plastic options. On average, drainage pumps are designed for a depth of 5 meters, but there are many models for a depth of 8-10 meters or more.

Impeller and volute material centrifugal pump. Most often, these parts are made of wear-resistant plastic or chrome-plated aluminum. For sump pumps designed to operate on highly abrasive waters, ceramic or cast iron parts may be used. Such nodes are repaired in all models in the same way - by replacing or installing a repair kit.

Special options for drainage pumps. To work with acidic or aggressive media, special pumps are used, in which the flow part is made of cast iron or special grades of bronze. If the pump is designed to work with hot liquids, most parts of the electric motor, seals, bushings and cuffs are made of silicon rubber or heat-resistant rubber. In addition, special protection of the power cord and additional cooling of the motor are used.

Conclusion

According to marketers, most people who have tried a drainage pump at least once in their work subsequently acquire one of the samples they like for the needs of the economy. Pumps are not cheap, but due to their high versatility, drainage units are gradually moving from the category of a curiosity to the category of an essential tool.

For the purpose of effectively controlling the level of surface water and ensuring that excess liquid is pumped out, it is customary to use drainage pumps. One of the world leaders in the production of this equipment is the Italian concern Pedrollo. A distinctive feature of its pump is the presence of a low residual water level during pumping. Some of them show a 2 mm residual liquid level, that is, they allow it to be pumped out virtually dry.

Obtaining an economic effect from pumping equipment begins with the stage of its acquisition. According to studies conducted by the US Department of Energy, over 65% of pumps are selected incorrectly. A similar situation is observed in Russia. Often, purchased equipment has insufficient or excessive capacity, and electric motors operate with constant underload or overload. With an illiterate choice of the pump, its parameters during operation go beyond the working areas of the characteristic. In this case, there is a violation of the normal course of work processes:

Conversely, a drain pump that is tailored to the specific application helps ensure long-term trouble-free operation and minimize costs. What aspects should be considered when choosing a drainage pump?

Characteristics of the working environment

The characteristics of the purchased pumping equipment must ideally match the operating conditions: climatic factors, temperature, physical properties and chemical activity of the pumped medium. It should be remembered that such equipment is intended for pumping out significant volumes of water, usually containing no more than 5–10% of mechanical impurities. It is recommended to install mesh filters in front of the drainage pumps to prevent large particles from entering the working bodies.

Diameters of solids in the pumped medium for Pedrollo drainage pumps must not exceed:

For all Pedrollo drainage models, the operating temperature of the liquid is not allowed to exceed +40 °C. An exception is the RX-VORTEX series, for which the operating temperature can reach +50 °C.

As for the chemical activity of the working medium, all Pedrollo drainage series are designed for pumping light polluted effluents that do not have chemical aggression to the materials of the pump construction.

Thus, the objects on which these pumps can be operated are: flooded basements, garages, storage rooms, rainwater runoff and ponds without a thick silt layer, provided that the pump is fixed on a solid surface (base plate). They should not be used in construction pits with a sand-gravel mixture, sewage wells with thick silt deposits, because in this case the drain pump will clog and its thermal protection will turn on.

Scope of use of drainage pumps

Drainage pumping equipment is widespread. It can be used:

Emptying level

An important characteristic of drainage pumping equipment is the level of emptying. The minimum level of emptying is demonstrated by the TOP-FLOOR series, in this case it is only 2 mm from the bottom.

Other series have the following emptying levels:

Calculation of the performance of the drainage pump

It is unlikely that drainage pumps will help save the facility from a serious accident on pipelines or from complete flooding. For pumping out small bays, the minimum productivity is enough. Such has, for example, the TOP-FLOOR series with a flow rate of up to 160 l / min., which is also able to provide pumping out virtually dry (2 mm from the bottom).

If the pump is to be equipped drainage system, then it is required to establish the intensity of the inflow of the pumped liquid. The method for calculating this parameter is simple.

The volume of supply water (To) is created from the volume of drainage water (Tdr), the volume of storm water (Td) and the volume of wastewater (Tst):

Stormwater volumes are defined as follows: Td = U * Y * C, where

It suffices to accept the following parameters of the nominal intensity of the shower:

The following consumption coefficients are accepted:

The catchment area (C) refers to the areas from which runoff enters the drainage system.

Wastewater inflow (Tst) depends on the number of people living in the house: Tst = 150 l / day for each person.

Thus, having determined the volumes of supply water, you should choose the appropriate model of the drainage pump. At the same time, its performance should be higher than the calculated maximum value. The excess limits are limited by the throughput of pipelines.

Consumers have the opportunity to choose Pedrollo pumps with different capacities:

Head calculation

To calculate the minimum required pump head, it is necessary to determine the distance over which water should be diverted and the height of its expected rise. The height is determined by the difference in height between the location of the pump and the point of discharge. In this case, it is necessary to take into account the pressure loss in the process of overcoming the hydraulic resistance of the pipeline. As a rule, the value of this indicator when crossing horizontal sections of pipelines is equal to 1 meter of pressure per 10 m of the pipeline (coefficient = 0.1).

Drainage pumps pump out water for us from pits, low-yield wells, basements, tanks for irrigation and cleaning of territories. On a suburban area, they have a lot of important functions that drainers can handle only with proper selection. Agree, there is little benefit from a device that is not used due to technical limitations.

We tell readers of the site in detail how to choose a drainage pump. We analyze what kind is required to perform a certain job. Here you will learn all the subtleties and technical criteria, according to which a suitable drainage pump model is determined.

The article presented for review lists all the factors that ensure an error-free choice. Popular drainage pumps are given as an example and described in detail, the quality of which has been verified by practice. The information content of the text is supplemented by photo and video applications.

Initially, these devices were created for pumping water from basements flooded with water. Later, the area of ​​​​use expanded. Modern models are designed for pumping lightly contaminated liquids from pits, wells, pools, pumping and cleaning wells.

In addition, they are used in production, included in the technological process. Most devices are capable of pumping liquids with impurities of about 10 mm in size.

Drainage pumps are specific equipment designed for a rather narrow range of work. It is not recommended to use it for other purposes. Despite the fact that drainers are used in shaft wells, they are not intended for permanent work in them.

The devices cannot work as a fecal pump either, although some "craftsmen" are trying to replace them.

Drainage pumps are designed for pumping and pumping clean or slightly contaminated liquids, can be used for draining small ponds, pumping and cleaning wells

Drainage equipment can only work with lightly contaminated liquids. The amount of solid impurities, depending on the type of apparatus, varies from 3 to 40 mm.