Parameters and design of drainage pumps. How to choose a drainage pump? Drainage pump minimum depth
A submersible drainage pump is designed to remove (pump out) water containing large insoluble inclusions, such as sand, silt, stones with a diameter of up to 50 millimeters (usually up to 35 millimeters). used for pumping contaminated water from flooded basements, garages, cellars and other residential and non-residential premises, for emptying any containers, artificial reservoirs (fountains, swimming pools), that is, in cases where it is necessary to pump out a large amount of water without wasting a lot of time.
The design of the submersible pump has proven itself and best suits the operational requirements and needs of users. The submersible drainage pump is made of durable plastic or stainless steel. The operation of such pumps involves placing it in the pumped liquid.
Submersible drainage pumps, as a rule, are equipped with a special float mechanism for turning the device on/off, which allows the pump to operate in automatic mode. A correctly configured mechanism automatically turns on the pump when the liquid level reaches a certain level. This function allows you not to be afraid of flooding of the cellar or basement, where such a danger exists. This also helps protect the pump motor from overheating, preventing it from running without water.
Let us note the main advantages of submersible drainage pumps:
- the pump is cooled by the pumped liquid, therefore it is capable of long-term continuous operation without the risk of overheating;
- ability to use at sub-zero temperatures;
- High efficiency can pump large volumes of liquid in a short time (30 m3 or more);
- almost silent operation of the pump.
- Protection against dry operation without water, the float switch drops with the liquid level to a critical level and turns off the pump.
It is also necessary to note the disadvantages or, more precisely, the features of submersible drainage pumps. Some models require the installation of special platforms, as well as the need to adjust the pump float switch. Due to the fact that the pump is in water, it is necessary to monitor the integrity of the supply wire to avoid short circuits and failure of the pump.
To choose the right submersible drainage pump, you need to know how they differ from each other. The main parameters that should be followed when choosing are the following:
- pump power, this indicator directly affects such characteristics as pressure and productivity, as a rule, pump power varies from 350 to 1300 W;
- pressure, one of the most important indicators, in the technical characteristics of the pump this parameter reflects the ability to raise water to a certain height; for household pumps this indicator varies from 5 to 15 meters. It is also necessary to take into account the distance over which the pump is capable of transmitting water. This distance can be easily calculated using the formula 1:10, that is, if the maximum height of water rise is 7 meters, then the water transmission distance will be no more than 70 meters, that is, if you need to pump out water from a depth of 3 meters, then the maximum water transmission distance will be 40 meters;
- productivity shows how much water a drainage pump can pump per unit time. For low-power drainage pumps, this figure starts from 5,000 liters/hour (5 m3); for the most powerful models, productivity can reach 20,000 liters/hour (20 m3) or more. Please also keep in mind that the description of the pump indicates maximum performance; as the height of the water supply increases, the performance of the pump decreases, so some manufacturers indicate both maximum and minimum performance;
- The immersion depth characterizes the depth to which the drainage pump can be lowered. For household pumps, this parameter does not exceed 10 meters.
Submersible drainage pumps can be divided into clean water pumps and dirty water pumps. A drainage pump for clean water is a pump capable of pumping water with inclusions up to 5 mm. An example of such a pump is. The advantage of this pump is that it has a mode for pumping out clean water to a minimum level, almost zero.
A drainage pump for dirty water is considered to be a pump capable of pumping water with inclusions from 5 to 35 mm. An example of such a pump.
Special mention should be made of submersible sewage/drainage pumps. This type of pump is specially designed for pumping liquids with high viscosity and inclusions of fibrous organic matter. It is best suited for draining a heavily polluted well, pumping out sewage, or silted reservoirs. In order to cope with such tasks, these pumps are equipped with more powerful motors and, as a rule, have greater productivity, such a fecal/drainage pump is.
Modern models require virtually no maintenance. Ease of use and ease of cleaning and replacing the filter is accessible to any user. Due to their versatility, submersible drainage pumps are deservedly in great demand.
No one will argue that water is vital for humans. However, there are times when it causes a lot of trouble. During periods of snowmelt or heavy rain, excess water can cause a lot of damage to buildings, washing away the foundation and flooding basements. A drain pump can serve as an indispensable assistant in such a situation. With its help, it is not difficult to pump out excess water, even if it has a certain degree of contamination.
Therefore, such a unit is indispensable in suburban farming. In addition, it can be used to pump out water from any reservoir, be it a swimming pool or a pit. Therefore, when purchasing a unit, it is worth thinking about how to choose a drainage pump so that it performs all assigned tasks with maximum efficiency.
Main components of a drainage pump
If you don’t really “dig” into the mechanism, the drain pump device consists of a motor and a pump unit, which are placed in a sealed housing.
It is made mainly of stainless steel or fairly durable plastic. The engine impeller is equipped with blades and is fixed to the rotor shaft.
The maximum size of solid particles allowed to be contained in the pumped-out medium depends on the size of the suction grille holes.
The pump unit sucks water through special holes, the diameter of which determines the maximum size of solid particles allowed to be contained in the pumped liquid. Most manufactured pumps are equipped with a float switch.
If you want to know how a sump pump works, watch a video of the process.
Such units can be used for both domestic and industrial work. Before deciding which drainage pump to choose, you need to find out the preferential conditions of use. This is necessary in order to determine the configuration of the mechanism. The main characteristics that you should pay attention to when choosing a drainage pump are:
- finding the suction hole; For professional units this feature is not important. They can be located in any position. For household pumps, it is better if the hole is located at the bottom. This will allow maximum pumping of water from the bottom of the tank.
- pump housing; For industrial use, mechanisms with a cast iron body are produced. They are quite reliable, but have a lot of weight. Household pumps, thanks to their housing made of steel or plastic, are more compact and lightweight. However, they have sufficient power to perform their functions.
- working chamber; To pump water without impurities, its size is unimportant. For liquids containing large fractions, the size of the working chamber must be sufficiently wide for their passage. Otherwise, the mechanism of the unit may be damaged.
- unit design; industrial models have a more complex design, which requires the involvement of a specialist when replacing filters and maintenance. Household pumps can be maintained independently.
- suction device; The centrifugal suction mechanism allows the pump to be used to pump out water containing solids without reducing power.
What material should the parts and body be made of?
This is an important characteristic for such a unit. Not only the price of the pump, but also its reliability and service life depends on it. Depending on the material used, pumps are:
- completely plastic; They are the least durable, but are cheaper than other analogues.
- plastic with stainless steel working mechanism; Thanks to this, the unit wheel is not exposed to aggressive environments and corrosion.
- stainless steel or cast iron; They lead the rating of drainage pumps in terms of durability due to the resistance of all parts to any damage.
Blade-type units are divided according to the material from which the parts are made. The blades for the pump are made:
- stainless steel; cheaper option.
- made of technopolymer, which is more resistant to corrosion and wear, but also costs more.
Classification by installation method
According to the installation method, drainage pumps are divided into:
- superficial; They pump out water even from great depths. They are mainly used in pumping stations for connection to a well or borehole.
- semi-submersible; The body of the unit is partially immersed in the pumped out liquid. Used for pumping water from cellars or small reservoirs.
- submersible; The pump is completely immersed in the pumped medium. Used for draining swimming pools and basements.
Devices that extend pump life
While the drain pump is operating, the engine may overheat, which can lead to damage to the unit. Also, the service life of the mechanism is negatively affected by its operation when the level of the pumped out medium is too low. A thermal relay will help to avoid engine overheating, turning off the unit when the temperature is exceeded.
The drainage pump with a built-in float turns off automatically when the liquid decreases during pumping. It can also turn on automatically when the room is filled with water. This will help avoid significant flooding in the absence of owners during a flood.
On and off sensors in pumps with an aquasensor control the operating mode of the unit; the devices are regulated independently of each other
Developments in this area do not stand still and units with new aquasensor technology are already on sale. Thanks to the regulator, you can set the required permissible water level to turn the unit on and off. In this case, the minimum level can be set to 5 mm. Such pumps can be installed in narrow tanks where float switch operation is not possible.
What technical characteristics should I focus on?
Performance is the most important aspect
To determine the required pump performance, you should find out the scope of the proposed actions. That is, how much water needs to be pumped out in a certain period of time. For example, household drainage pumps are capable of pumping out no more than 180 liters per minute. For tasks such as pumping out excess water from a basement or draining a swimming pool, such pumps are quite suitable.
However, you need to know that the higher the high reset point, the greater the loss in performance.
Required device pressure
To calculate the pressure required to perform a certain task, it is necessary to know the height and distance to which the water is supplied. The height is defined as the distance between the submersion level of the pump and the point where the water exits the nozzle. It is taken into account that there is a loss of one meter of pressure for every ten meters of hoses or pipelines.
Pump selection depending on the pumped medium
Each pump has a specific specification, which indicates the size of impurities contained in the water, which this unit is capable of passing without reducing its performance.
If the aggregates are distributed according to these characteristics, we obtain the permissible size of impurities:
- up to 5 mm; Used for clean or lightly contaminated liquids. Suitable for draining rainwater tanks and swimming pools.
- 5-25 mm; Used for moderately contaminated liquids with impurities not exceeding 25 mm. They are used to drain pits or wells.
25-38 mm
- ; Used for dirty, rain and melt water.
For dirty water, pumps are used that allow impurity sizes from 25 to 38 mm
Typically, household drainage water pumps are used in environments with a temperature of no more than 40º. Therefore, they are not suitable for pumping out hot water. For such functions, industrial units are chosen that can even cope with such a task.
There is a wide range of drainage pumps for summer cottages on the market. Therefore, if you need to perform several tasks: drain the pool and pump out water from the basement, you do not need to purchase a unit for each process separately. It is enough to choose one, but reliable pump. In this case, you should focus on the most labor-intensive of the processes.
For the purpose of effectively controlling the level of surface water and ensuring the pumping out of excess liquid, it is customary to use drainage pumps. One of the leaders in the world 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 demonstrate a 2-mm residual liquid level, that is, they allow it to be pumped out virtually dry.
Obtaining economic benefits from pumping equipment begins at the stage of its acquisition. According to studies conducted by the US Department of Energy Resources, over 65% of pumps are selected incorrectly. A similar situation is observed in Russia. Often purchased equipment has insufficient or excessive performance, and electric motors operate with constant underload or overload. If the pump is not selected correctly, its parameters during operation go beyond the operating characteristic zones. In this case, there is a disruption in the normal course of work processes:
On the contrary, a drainage pump that meets specific operating conditions allows you to ensure long-term trouble-free operation and minimize costs. What aspects should you consider when choosing a sump pump?
Work Environment Characteristics
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 drainage pumps to prevent large particles from entering the working parts.
The diameters of solid inclusions in the pumped medium for Pedrollo drainage pumps must not exceed:
For all Pedrollo drainage models, the operating fluid temperature is not allowed above +40 °C. An exception is the RX-VORTEX series, the operating temperature for which can reach +50 °C.
As for the chemical activity of the working environment, all Pedrollo drainage series are designed for pumping light, contaminated wastewater that does not have chemical aggression towards the pump construction materials.
Thus, the objects where these pumps can be used are: flooded basements, garages, warehouses, storm drains and ponds without a thick layer of sludge, provided that the pump is fixed to a solid surface (base plate). They should not be used in construction pits with a sand-crushed stone mixture, or sewage wells with thick silt deposits, since in this case the drainage 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 TOP-FLOOR series demonstrates the minimum level of emptying, in this case it is only 2 mm from the bottom.
Other series have the following emptying levels:
Calculation of drainage pump performance
It is unlikely that drainage pumps will help save a facility from a serious pipeline accident or from complete flooding. For pumping out small bays, the minimum capacity is sufficient. This is available, for example, in the TOP-FLOOR series with a flow rate of up to 160 l/min, which is also capable of providing virtually dry pumping (2 mm from the bottom).
If it is intended to equip a drainage system with a pump, then it is necessary to set the intensity of the inflow of the pumped out liquid. The method for calculating this parameter is simple.
The volume of inflow 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 determined as follows: Td = U * Y * C, where
It is enough 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.
The influx of wastewater (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 select a suitable drainage pump model. In this case, its productivity must be higher than the calculated maximum value. Excess limits are limited by the throughput of pipelines.
Consumers have the opportunity to choose Pedrollo pumps with different capacities:
Calculation by pressure
To calculate the minimum required pump pressure, it is necessary to determine the distance to which the water should be discharged and the height of its expected rise. The height is determined by the difference in height between the pump location and the discharge point. 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 pipeline (coefficient = 0.1).
A drainage pump is a hydraulic device that transfers the mechanical energy of the engine drive to the fluid flow, giving it pressure in motion. The device can also move a mechanical mixture of liquid with solid colloidal substances contained in it.
The device can be selected to move any liquid – clean, partially contaminated, dirty or even aggressive. In order to give the liquid movement, the content of mechanical impurities in it is allowed from 5 to 10%.
How does it work?
A drainage pump is exactly that hydraulic machine that is capable of pumping out large volumes of water with impurities. Drainage (from French drainage) means the removal of liquid or liquid mixtures both from the surface of the earth and from under it. The equipment can be used for pumping liquid from the surface of flooded areas, from wells, basements, swimming pools, from various reservoirs - construction pits, drainage pits, mines, industrial systems, from treatment facilities and installations, from domestic sewer pipelines.
On an industrial scale, a drainage pump is used to pump waste mixtures, when supplying water for cooling, to maintain the water level in intake tanks, and in reservoirs.
At construction sites, such a pump pumps out groundwater, clears flooded areas, pits filled with sand or silt. It also pumps liquid solutions containing sand or lime impurities and controls the level of sewage water.
The drainer is also used in everyday life - when irrigating greenhouses or agricultural land, when clearing silt from ponds and wells.
It has a relatively low pressure, but is characterized by a high rate of liquid pumping speed. This is its distinctive feature. This type of pump not only quickly pumps large volumes of liquid, but also consumes little energy.
How it works?
The drainage pump is equipped with an impeller, which is driven by an electric motor. The movement of liquid occurs due to the fact that the impeller creates an area of high pressure at the outlet hole, and an area of lower pressure at the intake hole. Productivity will drop sharply if the device does not provide the required outlet pipe diameter. Moreover, the device may fail. The impeller is designed in such a way that it will not allow the equipment to be used under high pressure conditions; you should remember this when choosing a drainage pump.
During operation, the drainage pump is completely immersed in the pumped medium - in the liquid, where it is simultaneously cooled. Sometimes the so-called “dry” method of operation is allowed, when the device is on the surface.
Many models of this mechanism are equipped with an automatic device that automatically turns on the pump if a certain level of the pumped liquid is reached. The drainer can also be equipped with a cutting mechanism to grind large impurities.
The main characteristics are pressure and flow in m3/hour, which is determined by the structure of the impeller and engine power.
Drainage pumps are divided into surface and submersible. The first ones are installed at the edge of the drain pit, where only the hose is immersed, along which the pumped mixture rises. Submersibles sink to the bottom below the level of the pumped liquid. Water is sucked in through holes in the bottom, which is equipped with a special mesh filter to protect against large mechanical particles entering the impeller.
The submersible drainer is equipped with a special plastic bubble or float, which signals when a certain controlled level of liquid has been reached, as a result of which the device automatically turns on.
The submersible pump is manufactured with high-quality electrical insulation to prevent electrical short circuits, which is quite logical for a device immersed in a liquid medium.
Important characteristics of drainage pumps are operational safety, reliability and durability, power combined with the performance of the device.
This hydraulic mechanism may differ in its characteristics depending on the media with which it works - dirty, clean, moderately dirty. Therefore, choosing a drainage pump is a responsible task.
You need to proceed from what kind of medium is to be pumped out - a pure liquid (for example, water from a tank or well) or a liquid mixture (for example, water with sludge from sewers, mines). Often the purpose lies in the name of the equipment brand. The passport or instructions for the pump often indicate the permissible dimensions of solid suspensions in the pumped liquid (5-60 mm).
Requirements for immersion depth and pressure
The main requirements for this device are performance, immersion depth and pressure.
A drainage pump for domestic needs, for example, for pumping water from a 40 cubic meter home pool, can be selected with a capacity of 8-10 m 3 /hour.
To carry out large-scale professional work, you will need equipment with a capacity of 100 to 200, and possibly from 500 to 700 m 3 /hour.
The pressure of the drainage pump varies from 5–10 meters to 25–50 meters. It all depends on the distance over which the pumped mixture will have to be supplied. The vast majority of models are designed for pressure up to 10 m. More powerful ones are designed for deep work below 25 meters or more. Most devices are submersible to a maximum of 5 meters.
If the instructions for the device indicate a pressure height of 8 meters, this means that this drainage model is capable of transmitting liquid over a distance of 80 meters. These figures are, of course, approximate, since it is necessary to take into account other parameters - immersion depth, hose diameters, etc. A specialist with whom you should discuss all the details and features of the pump when purchasing it will help you understand this issue.
Requirements for temperature indicators and material of manufacture
Temperature indicators of the environment are an important parameter. Typically, most pumps are designed for a 40-degree environment. To pump out chemically aggressive, hot media, you should select a drainer of a special design, for professional purposes. They are in demand by rescuers, utility workers, and construction workers.
How to choose a drainage pump, taking into account the material from which it is made? Traditional models made of stainless steel or cast iron are characterized by high wear resistance. If the environment is aggressive, then the shaft of the device should be made of ceramic. Today, polymers are also used in production.
Other characteristics
The specificity of the device lies in the diameter of the pipes. The usual value of this indicator is 0.5-1.5 inches. To pump a coarse liquid mixture, a diameter of 8-10 inches will be required.
Portability of the device. This indicator is more important for everyday use of a drainage system. It is much more convenient and easier to carry a device made of plastic than to move a heavy cast-iron pump from place to place.
The variability of use of the unit is important in any case, especially for domestic purposes.
Your pump will be a good helper if it is capable of pumping not only clean water from a well, but will also save your country house from destruction when the basement is flooded with groundwater with silt or rainwater with washed away soil.
Residual water level. This indicator can ensure pumping of liquid almost to a dry residue if its design allows it to achieve a minimum residual level of 2 mm.
A tank, basement, utility room, garage on the territory of a country house, swimming pool, pond, artificial lake with a hard bottom can be completely emptied or removed dry with a medium-power drainage pump if it is immersed in a bucket, in a vat, on a slab of plywood or metal Pumping wastewater with sludge (from a ditch, trench) or from a well that does not have a solid base, where stones, leaves, pebbles or various debris are most likely to be found, is unlikely to be drained. Here it is necessary to choose equipment of a different power for a heavily polluted environment.
Among pumps for various purposes, drainage pumps are the most versatile devices. Devices of modern brands require virtually no maintenance. Their design is thought out in such a way that any owner can clean or change their filters.
Video
This video also covers choosing a sump pump.
