If you are deciding which well pump is better: centrifugal or screw, you need to learn more about the intricacies of their operation and maintenance, and study the basic parameters. They take into account the conditions in which the equipment will serve. The deeper the hydraulic structure, the more productive the unit should be.
Twin screw pumps.
Screw pumps
When choosing devices, the mechanism of action is taken into account. The screw unit operates on the principle of pushing water out by screws that rotate inside a grooved housing. As a result, liquid is captured in small quantities and rises to the top. Such devices can be used in different environments: viscous, fluid, chemical reagents. However, it is not recommended to use them for pumping liquids containing large or hard fractions, which can cause rapid wear of the mechanism components.
Screw pumps are suitable for installation in hydraulic structures of small diameter. They have a lower price and can lift water from different heights. Their efficiency is lower than that of their analogues, so the units consume more electricity, which contributes to an increase in energy consumption. Considering that such devices quickly fail when working with liquids containing sand, the possibility of repair should be taken into account. The cost of a repair kit for screw pumps is lower compared to analogues.
To increase the service life of such units, it is necessary to protect the mechanism from silt and sand. For this purpose, a filtration system is provided. Screw devices are also called screw devices. The main purpose is installation inside a hydraulic structure. If it is necessary to lift water from greater depths, submersible models of such equipment are purchased.
Screw pump.
The advantage of the devices is the ability to provide a pressure of significant force, while the liquid flies out over a distance of 50 m. The unit, equipped with a screw, in this case is characterized by high operating speed. This allows you to quickly lift the liquid, as the auger rotates intensively.
The screw of this type of unit is connected to a drive shaft, which is connected to the engine. When the device is turned on, the shaft rotates, at the same time the auger is set in motion and begins to lift water from the bottom of the well. It is important that the device is located inside the hydraulic structure at a distance of no more than 5 m from the lowest point.
If it is necessary to lift liquid from great depths, and it is also important to ensure high productivity of the equipment, large-sized devices should be considered. The longer the auger, the stronger the water pressure. Such models are suitable for installation in wells. In this case, the diameter of the casing is small enough to allow the unit to be passed through the casing.
Common models of screw pumps
Devices in this group differ in basic parameters, so it is necessary to study the characteristics of the most popular units:
Models of screw pumps.
- Whirlwind CH-60B 68/3/8. The cost of the pump is 4900 rubles. Power is 370 W. The device raises water to a height of up to 60 m. Its productivity is 25 l/min. The disadvantage is the lack of a dry running function. This means that if the water level in the well decreases, the pump overheats, since it cannot stop on its own when draining the hydraulic structure. The diameter of the unit is 75 mm. It can be used to work with liquids whose temperature does not exceed +35°C.
- AquamotoR AR 3QGD1.95-90 AR151019. The cost of this model is 6,000 rubles. The unit has a power of 550 W. The advantage is the significant height of water rise - 90 m. The productivity of the device is 32.5 l/min. The design does not provide protection against dry running. Pump diameter - 75 mm. The permissible immersion depth is 30 m. In this case, the minimum diameter of the well is 100 mm. The unit can withstand pressure of 9 atm. It can be used for pumping liquids whose temperature is +1…+35°C.
- ALBA 4QGD2,1-170 AL161007. This device can be purchased for 7,000 rubles. It is distinguished by a power of 750 W. The advantage is the high water lift height - 170 m. At the same time, the productivity is 56.6 l/min. The unit can be submerged to a depth of 30 m. There is no protection against dry running. The diameter is 100 mm. The pump can withstand pressure within 17 atm. It can be operated at temperatures of +4…+35°С.
Not everything that is expensive is ideal
Screw pumps appeared later than centrifugal pumps, but quickly gained trust and their place both in the water supply industry and in other areas. It is difficult to imagine a competition between a propeller and a propeller in pumping tar, bitumen or air.
Each pump has its own tolerances for the media it can handle, but in the area of water, the screw and centrifugal pumps have equal starting positions. We are not talking about cost, size and maintainability here. There is one more very important point.
Humanity has been moving towards tube electrical engineering for a very long time, towards transistors - faster, towards microelectronics - very quickly. When the equipment worked on tubes and transistors had already appeared, there was a remarkable case.
Something unexpected (a pulse, radiation or a solar flare) struck all the transistor devices in the military unit (air defense), and it went “blind”. Fortunately, the other unit did not have time to abandon the lamps and the target was hit in a timely manner.
Water supply at home is not the border of the state, but an unforeseen refusal of the natural benefits of civilization is unacceptable. Buying a reputable Grundfos, but having a water tank on the roof and an outdoor toilet for emergencies is not a solution.
It is ideal and always possible to create a safe and protected operating environment for the pump and do this during the pump selection process. It doesn’t matter what brand the screw or centrifugal pump will be. The design and principle of operation of these units are similar, so just “try them on” to your realities.
Centrifugal pumps
The mechanism of action of such devices is based on the creation of centrifugal force, which is realized thanks to the impeller. When the pump is turned on, the drive shaft begins to move. It has a wheel installed on it. The faster it moves, the higher the productivity of such equipment. Most often, the design provides for 1 impeller. Several of these elements are used to improve performance.
Centrifugal pump.
The advantages include versatility. Thus, centrifugal units come in two varieties: surface and submersible. However, pumps of this type can operate with liquids containing sand. Their price is higher than their screw counterparts.
Rating of the most popular models:
- PATRIOT SP3250 S 315302463. You can purchase a unit of this type for 5100 rubles. Power is 750 W. Dry running protection is not provided. The height of water rise is 80 m. The productivity is 32 l/min. The diameter of such a device is 101.6 mm, while the size of the well should be 110 mm. The pump can withstand pressure of no more than 10 atm. It can be immersed to a depth of up to 30 m. The unit is recommended for pumping liquids whose temperature does not exceed +40°C.
- Caliber NPTS-2.8/40-250. The average price of this model is 7,000 rubles. It is distinguished by a minimum power of 250 W and a relatively low water lifting height of 40 m. At the same time, the unit’s productivity is significant - 46.6 l/min. The pump can be installed at a depth of up to 40 m. Of the models considered, this option is the most compact - the diameter is 70 mm. Despite this, the minimum well size is 102 mm. The unit can withstand low pressure - up to 4 atm. The recommended temperature of the pumped liquid is +40°C.
- Whirlwind CH-60 68/3/7. The price of such a device is 10,000 rubles. It exceeds its analogues in power - 800 W. However, the unit raises water to a relatively small height - 50 m. Productivity - 50 m/min. The device can be installed at a depth of no more than 40 m. The pump diameter is 75 mm, which corresponds to the minimum well size. The recommended temperature of the pumped liquid is not higher than +35°C. The design does not provide protection against dry running.
Recommendations for selection
When choosing a pump, you should give preference to devices with a steel or cast iron body, as they are more durable. To prevent the device from breaking due to voltage surges in the electrical network, it is recommended to install surge protection. To prevent working elements from wearing out too quickly, filters should be installed.
To protect the pump from overheating and dry operation, it is better to install sensors if it is not equipped with them in advance. When calculating power, you should choose a device that is 20% more powerful so that it does not constantly work at maximum loads, as this will quickly lead to its breakdown.
Should you choose a screw or centrifugal pump for a well?
In terms of performance, centrifugal devices are superior to their screw counterparts. They are used if you need to ensure a regular supply of water. Moreover, they pay attention to the quality of the liquid. If there are impurities in the water, it is recommended to use a screw unit. However, the centrifugal analogue better tolerates contact with solid fractions (sand), despite the fact that it is also gradually subject to wear.
When choosing units, take into account the size of the well. Both centrifugal and screw pumps have installation restrictions. Thus, the minimum permissible diameter of a well for installing a device with certain parameters is set. Based on these characteristics, any of the units under consideration may be suitable. However, it is often recommended to install a screw at a shallower depth. The price should also be taken into account. Centrifugal pumps are more expensive.
Practice and reality
The only job of a pump is to pump something somewhere. In the area of their mass use, we are most often talking about water for water supply purposes in a populated area, home, country house, garden or vegetable garden.
The market for screw and centrifugal water pumps and related equipment is represented by a huge range of products that can satisfy the most complex plan for supplying water from a well, borehole, pond or clean spring to a house or garden for drinking purposes or for irrigation.
There are many companies that offer their websites and videos on how and what to do. To simple questions about whose products to prefer, for example, Wilo or “Rucheek”, and which pump is better: centrifugal or screw, there are a lot of answers that contradict each other.
All this leads to a variety of situations in real practice:
- For some, everything works;
- for others, the pump burned out at the first contact with the water surface;
- Still others, after the banquet, not only had a headache in the morning, but also lost their water;
- For the fourth, specialists made a well, but forgot about the passport for it;
- the rest have a lot of other situations.
Combining the capabilities of the “pumping” market and its specialists with real practice, we can confidently say: “For reliable water supply, a pump (centrifugal or screw) is not the main thing.” Important for him:
- source parameters;
- consumer parameters.
If you objectively and accurately assess the capabilities of the well, if you correctly calculate the real needs of the house, then the latter will always have water in the water supply network, and the well will have a long life.
Internal or external
Surface devices are designed for wells and shallow wells. The distance to the water surface should not be more than 8-9 m. For wells with greater depth, submersible pumps are installed, which is why they are also called deep pumps.
Surface devices are placed outside the well. This makes them easy and convenient to maintain. They are often installed together with a storage tank to stabilize the pressure in the system. But because the surface pump operates outside the well, it makes a lot of noise and also takes up space. As a result, it is necessary to arrange an area for it and build a building to absorb sounds. Since the pump is out of the water, its motor is not cooled by it.
Layout of internal and external pump for a well
Submersible devices are divided into several types:
Vortex pumps have one impeller. It draws water into the inner part and pushes it out into the outer part, due to which a vortex appears. As water passes through the wheel, its speed and pressure increase. The design of these pumps is simple, so they have a low price. But because of this, they have low efficiency and are unable to work with liquids that contain sand or other similar impurities, as this leads to rapid wear of the device.
Vortex pumps are recommended for use in wells with low flow rates or when a small water supply is required.
Vortex pump device
The main working element of a screw device is the screw (auger). Water, getting inside the pump, is gradually pumped by the auger, eventually pressure appears and the liquid is forced out. Just like the vortex device, the screw device has a simple design and low price. Recommended for use in wells with low flow rates. But compared to a vortex pump, a screw pump is more resistant to impurities in water.
Screw pump design diagram
Areas of use
Screw pumps are most often used in the following industries.
- Oil and gas industry
- Chemical industry
- Water purification and water treatment
- Pulp and paper industry
- Paint industry
- Food
- Pharmaceutical
- Shipbuilding and shipping
For the following tasks:
- Pumping multiphase liquids
- Heavy oil pumping
- Screw well pump for water injection to increase oil recovery
- Production of alcohols and solvents
- Pumping bitumen, tar, resin
- Food products
- Paints, glue
- Rubber
Source: https://smsorenburg.ru/vodosnabzhenie/otlichie-vintovogo-ot-centrobezhnogo-nasosa-2.html
The optimal choice of equipment for water supply at home
Today, as a rule, an artesian well is used to supply a home with clean drinking water. Despite this, the vast majority of users still use water filtration.
However, the best pump for delivering drinking water to the house is centrifugal pumping equipment. The water rises to the surface due to the unwinding of the pump rotor. Centrifugal forces push out the water, delivering it through the created communications to the intake points.
The advantages of centrifugal pumps are obvious:
- huge resource (practically does not break if used correctly);
- high efficiency (uses expended electricity as efficiently as possible);
- compact sizes.
Indeed, all those who chose a centrifugal pump bought it solely in the hope of long-term and trouble-free operation. The pump works efficiently to provide the required amount of water for your home.
In addition, centrifugal pumps can operate even in the presence of a small percentage of impurities. In the case of a well, naturally, we are talking about sand.
The optimal choice of equipment for water supply at home
Today, as a rule, an artesian well is used to supply a home with clean drinking water. Despite this, the vast majority of users still use water filtration.
However, the best pump for delivering drinking water to the house is centrifugal pumping equipment. The water rises to the surface due to the unwinding of the pump rotor. Centrifugal forces push out the water, delivering it through the created communications to the intake points.
The advantages of centrifugal pumps are obvious:
- huge resource (practically does not break if used correctly);
- high efficiency (uses expended electricity as efficiently as possible);
- compact sizes.
Indeed, all those who chose a centrifugal pump bought it solely in the hope of long-term and trouble-free operation. The pump works efficiently to provide the required amount of water for your home.
In addition, centrifugal pumps can operate even in the presence of a small percentage of impurities. In the case of a well, naturally, we are talking about sand.
