Drainage pumps for sewerage: types of pumps for pumping, rules of choice

The main tasks, which are solved by autonomous sewer systems of country houses and country buildings, are, to ensure timely removal of wastewater and its treatment. For efficient and uninterrupted operation of such systems, they must be regularly serviced (in particular, pump out the bottom sludge and clarified liquid from the septic tank or sewer pit, for which the drainage pump is used).

Drainage pump, which is used to pump out the septic tank

Drainage and fecal type pumps: similarities and differences

Though, that pumps of drainage and fecal type carry out the same task - provide transportation on the pipeline of the polluted liquid environments, such devices differ in design, and technical characteristics. The main difference between drainage and faecal pumps is the maximum allowable size of insoluble inclusions, contained in the pumped liquid medium. So, depending on the type of electric sewage pump, such a device can be used for pumping contaminated liquids, containing insoluble this document included the following size:

• 30-50 mm (drainage pump for sewage);
• 3-12 mm (faecal pump for sewage pumping).

Externally, drainage pumps may differ slightly from fecal ones

By itself, the design of the pump unit of fecal type devices is not intended for pumping liquid media with solid inclusions of such a large size. That is why any faecal pump contains a special device in its design, whose task is to grind insoluble inclusions of large size, contained in the pumped liquid medium.

Such a device, which is installed on the inlet pipe of the pumping unit and prepares the effluent for further transportation, is an impeller, the blades of which perform the function of grinding insoluble inclusions. In addition to the latter, the impeller of the fecal pump can grind and fibrous inclusions, present in the pumped media, which can seriously complicate the operation of pumping equipment. Such inclusions, in particular, there may be hair, toilet paper, etc..

Fecal pump with shredder

Drainage pumps for sewerage, unlike fecal type devices, are not equipped with the crushing mechanism, therefore, they can be used for pumping liquid media with insoluble inclusions of small size (5-12 mm). Drainage pumps of drainage type are very critical in the composition of pumped media of animal hair and wool, which can wind on the impeller and eventually disable the device. That is why, using sewage pumps of this type, the pumped medium should be filtered.

Sewage pumps as fecal, and drainage type, usually, pump the liquid medium with a wheel with blades, installed inside their housing. Turning, the wheel blades create a vacuum in the suction line, which ensures the suction of fluid into the working chamber of the pumping equipment. When the fluid is inside the pump and its movement together with the blades, it is affected by centrifugal force, which leads to an increase in pumping pressure and its ejection through the discharge pipe.

Drainage pump device

Given that fact, that fecal pumps for sewage in a private home perfectly cope with the pumping of liquid media, containing rather large insoluble inclusions, a natural question arises, why choose drainage devices at all. Meanwhile, the feasibility of this choice is due to a number of advantages of drainage pumps. To such advantages, in particular, include:

• affordable price (due to the simpler design, drainage pumps are much cheaper than fecal devices);
• great variety of models, presented in the modern market (such variety allows to pick up the pump for the sewerage in the private house without special difficulties, whose technical characteristics will optimally meet the required parameters);
• the absence of a grinding device in the design (due to this, the drainage type pumps are compact in size).

Where drainage pumps are used

The design features of the drainage pump do not allow it to pump sewage immediately after the toilet. Insoluble inclusions of large size, present in such effluents, can cause serious damage to the design elements of the device and quickly disable it. With the help of hydraulic machines of this type, usually, sewage is pumped from septic tanks and sewers. Being in such storage tanks, pumped sewage waste is exposed to anaerobic bacteria, resulting in changing composition, the size and consistency are contained in the liquid inclusions. The result of such biological effects is the transformation of insoluble inclusions in sludge and water, with the pumping of which the drainage pump can already cope without compromising its technical condition.

Essentially, the drainage pump is a drainage pump, by means of which the liquid medium is pumped out from the accumulative tank of sewer system. Using such a dehumidifier pump for that, to pump sewage in a private home, it is possible to remove from the accumulative tank of system not only the clarified liquid, but also wet silt masses.

The main types of sewage pumping units

Before looking for answers to questions about that, how to choose a drainage pump to equip an autonomous sewer system, it is necessary to understand the varieties of such devices. One of the criteria for dividing drainage pumps into different types is location, in which the pump sewer installation will be operated. Depending on this parameter, sewage pumps can belong to one of the following types.

Submersible drainage pump

Submersible sewage pumps are completely immersed in the medium and have at a certain distance from the bottom of the storage tank, the value of which is specified in the instructions for the equipment. Submersible drainage sump pump can be used as a mobile device or installed in storage tanks permanently, for which metal guides are used. Because the submersible drainage sump pump is constantly in a liquid medium, noise level, which it creates at work, is minimal.

Varieties of submersible pump installation

Surface sewage pump

Surface pump installation, as its name implies, is installed outside the storage tank, on the surface of the earth. At the same time the pumped environment in the drainage pump of surface type arrives on a pipe or a hose, the lower part of which is lowered into the storage tank. Surface drainage pumps, usually, installed stationary, pre-preparing the site for installation.

Ease of operation of surface pumping units is, that they are always accessible. This allows you to quickly identify faults in their work, with lower costs to carry out their maintenance and repair.

Areas of application, advantages and disadvantages of drainage pumps

Different models of drainage pumps differ not only in design, but also the operating conditions, what to consider, choosing pumping equipment.

Submersible drainage pumps

Immersion drainage device is the most popular pump for pumping sewage at home. To pump out the sewer with it, it is completely immersed in a liquid medium to a certain depth, while suction is pumped through the bottom of the device. Installation of the sewage pump of submersible type in the accumulative tank is carried out by means of a cable, and the pumped liquid is transported on a flexible hose or on a pipe. To protect the submersible drainage pump from getting into its inner chamber insoluble inclusions of large size, at its bottom, through which suction is carried out, install a protective grille. Drainage-fecal pumps can be used as submersible, equipped with grinding mechanisms.

Drainage pumps with float valves provide automatic operation of the pumping unit

Many modern models of submersible drainage and sewage pumps are equipped with float valves, allowing to automate work of such equipment. Valve, mounted on the pump housing, automatically starts the equipment at that moment, when the liquid, which fills the storage tank, reach the float. As soon as the liquid level in the storage tank drops to the required level, float go down, and the valve will automatically operate and turn off the device.

The advantages of submersible drainage pumps include:

• compact size and, in accordance, high mobility;
• low cost (when compared with drainage and fecal pumps);
• versatility (you can use them not only for that, to pump out the sewer, but also in order to remove the accumulated water from the basement of the house).

The above advantages of submersible pumping units determine that fact, what is equipment, in contrast to surface drainage and fecal pumps, most often choose for the house or cottage.

If we talk about the disadvantages of submersible drainage pumps, then the most significant of them should include that, that the cooling of the drive motor of the equipment is carried out only due to the pumped liquid medium. If for any reason the device will run idle, its electric motor will quickly overheat and fail. That is why when operating such a hydraulic machine it is necessary to control the correct operation of the float valve and monitor, so that the device does not work just like that.

Example of overheating of the pump motor due to incomplete immersion in water

Surface drainage pumps

Surface drainage pumps, if you compare them with submerged, Are more powerful and reliable devices, able to function smoothly for a long time. In their design there are suction and discharge pipes, to which the drainage sewer is connected.

Surface type pumps are selected for maintenance of accumulative sewage tanks, characterized by considerable volume and great depth. The design of such pumps includes a drive motor, the rotation of the shaft which is transmitted to the rotor with a wheel with blades mounted on it. Due to the rotation of the wheel is suction into the inner chamber is pumped and pushing the latter into the discharge line under a certain pressure.

Self-priming surface pump for pumping dirty water

Carrying out installation of the surface drainage pump on a specially prepared platform, it is necessary to provide protection of the driving electric motor against moisture hit, which may be the cause of its failure. Automation of the surface drainage pump is also carried out using a float sensor, placed in the storage tank.

The principle of operation of pumping equipment

The drainage pump has a simple principle of operation: due to the rotation of the impeller in the suction pipe creates a vacuum, which facilitates the entry of liquid medium into the working chamber of the device, where it begins to move along with the wheel blades. Ejection pumped through the discharge pipe is due to the action of centrifugal forces on the liquid, created by the rotation of the impeller.

For the work of drainage pumps as submersible, and surface type in automatic mode, as mentioned above, corresponds to a special sensor of the float type, placed in the storage tank, from where the liquid medium is pumped out. When the liquid level in the tank increases, such a sensor automatically starts the pump, and when reduced to the required level - disables.

The principle of operation of the drainage pump with a "float"

Which model to choose

Deciding on that, which drainage pump to choose for pumping fluid from the sewer system, the set of conditions should be analyzed, in which such a device will be used. It should be borne in mind, that the operation of the drainage pump will be effective only if, if its technical characteristics fully meet such conditions.

Among the parameters, which must be taken into account, deciding on that, which dirty water pump to choose, can be distinguished as follows, as:

1. composition of the liquid medium, which will be pumped, the presence of impurities in it, their type and size;
2. the temperature of the pumped liquid medium;
3. the presence in the composition of the pumped liquid medium of chemically aggressive impurities, which may appear in it when used in a non-biological septic tank, and the chemical method of decomposition;
4. number of drains, coming into the storage tank;
5. depth of the storage tank;
6. characteristics of the place, on which it is planned to install a surface drainage pump;
7. distance, to which it is necessary to transport the liquid medium is pumped;
8. mode, in which the pumping equipment will be operated (periodic inclusions, seasonal or permanent use).

Comparative table of some models of drainage pumps

So, to choose a drainage pump is not enough just to look at a photo of such a device in the online store, it is necessary to study its technical characteristics. To such characteristics, in particular, include:

• power, which characterizes the amount of fluid, pumped by the device per unit time (l / min);
• the created pressure of liquid, which is measured in meters of water.

The algorithm for selecting a drainage pump after analyzing all the output parameters is as follows: compare the characteristics of different pump models with the output parameters and select the one, which most fully corresponds to them.