Wet rotor motor. Pumps for heating with a "wet" rotor

It was believed by many that for domestic performance it is necessary to take circulation pumps with wet rotor. Dry rotary circulation pumps were used for industrial use.

There was an opinion that pumps with a dry rotor have too big sizes and make a lot of noise. However, large manufacturers began to produce more and more household models circulation pumps with a dry rotor.

Dry rotor circulation pumps are used in industry.

In the domestic version, circulation pumps with a wet and dry rotor are used. For production needs, pumps with a wet rotor are not used, since they can be produced with a power of up to 3 kW and they are not widely used.

Advantages of dry rotor circulation pumps industrial design: the quality of the coolant is not important for them, they have good maintainability. The disadvantage of these pumps is that they are large, very noisy, so they are installed in separate rooms, they consume a lot of electricity.

As for the household version of the pump with a dry rotor, its advantages:

has a higher efficiency;

for him, the purity of the coolant is not important;

has good maintainability, and spare parts are cheaper than pumps, having a wet rotor;

almost does not differ in size from the wet rotor counterpart.

The downside is a lot of noise during operation and the need for regular replacement of the mechanical seal.

The disadvantages of circulation pumps with a dry rotor are pluses for a pump with a wet rotor: noiselessness, does not have a mechanical seal. The disadvantage is that the quality of the coolant has great importance during operation. The worse the quality of the pumped liquid, the faster the pump can fail.

Considering all the minuses and pluses of the considered pumps, we can draw the appropriate conclusions. If the quality of the coolant is not important to you, then it is better to choose a pump with a wet rotor, but it is not known what will happen to the rest of the heating system.

If you want everything to work smoothly, it is better to use a dry rotor motor, but you also need to take care of the quality of the coolant.

As for the noise, everyone decides for himself, because the pump does not often come into view. The efficiency is not so important, since the percentage difference is small, but the absence of the need to replace the mechanical seal is a big plus.

But maintenance should be carried out regularly, together with an inspection of the entire heating system by a specialist.

Heating systems are divided into systems with natural (gravitational) and forced circulation. In systems with forced circulation, the installation of a circulation pump is mandatory. Its task is to ensure the movement of the coolant through the system at a given speed. And in order for it to cope with its task, it is important to choose the right circulation pump.

Purpose and types

As already mentioned, the main task of the circulation pump is to ensure the required speed of the coolant through the pipes. For systems with forced circulation, only under such conditions will the design capacity be reached. During the operation of the circulator, the pressure in the system increases slightly, but this is not its task. This is rather side effect. There are special ones to increase the pressure in the system.

There are two types of circulation pumps: dry and wet rotor. They differ in design, but perform the same tasks. To choose the type of circulation pump you want to install, you need to know their advantages and disadvantages.

Dry Rotor

It got its name due to the design features. Only the impeller is immersed in the coolant, the rotor is in a sealed housing, it is separated from the liquid by several sealing rings.

The device of the circulation pump with a dry rotor - only the impeller in the water

These devices have the following properties:

• They have a high efficiency - about 80%. And this is their main advantage.
• Require regular maintenance. During operation, solid particles contained in the coolant fall on O-rings, breaking the seal. To prevent depressurization and maintenance is required.
• The service life is about 3 years.
• Publish at work high level noise.

Such a set of characteristics is not very suitable for installation in heating systems of private houses. Their main advantage is high efficiency, which means less energy consumption. Therefore, in large networks, circulation pumps with a dry rotor are more economical, and they are mainly used there.

wet rotor

As the name implies, the equipment of this type both the impeller and the rotor are in the liquid. The electrical part, including the starter, is enclosed in a metal sealed glass.

Glandless pump design - dry electrical part only

This type of equipment has the following properties:

• The efficiency is about 50%. Not the best indicator, but for small private heating systems this is not critical.
• Maintenance is not required.
• Service life - 5-10 years, depending on the brand, mode of operation and condition of the coolant.
• During operation, they are almost inaudible.

Based on the above properties, it is not difficult to choose a circulation pump by type: most stop on devices with a wet rotor, as they are more suitable for working in an apartment or a private house.

How to choose a circulation pump

Each circulation pump has a set of technical characteristics. They are selected for the parameters of each system individually.

We select technical characteristics

Let's start with the selection of technical characteristics. There are a lot of formulas for professional calculation, but to select a pump for the heating system of a private house or apartment, you can get by with averaged norms:

Choosing a circulation pump for heating following these rules is easy. Calculations are elementary. But I must say that these figures are average. If your house at some point is very different from the "average", you need to make adjustments either upward or downward technical characteristics. For example, you have well insulated the house, the capacity of the previously purchased boiler turned out to be excessive. In this case, it makes sense to take a pump with a lower capacity. In the opposite situation - it is chilly in the house in extreme cold - you can put a more productive circulator. It will temporarily solve the problem (in the future it is necessary either to insulate or change the boiler).

Model selection

When choosing a specific model, pay attention to the graph with the pressure characteristic of the pump. On the graph, you need to find the point at which the values ​​​​of pressure and productivity intersect. It should be in the middle third of the curve. If it does not fall on one of the curves (there are usually several of them, characterizing different models), they take the model whose graph is closer. If the point is in the middle, take the less productive one (the one located below).

What else to pay attention to

In the technical characteristics of circulation pumps, there are several more positions that you should pay attention to. The first - allowable temperature pumped medium. That is, the temperature of the coolant. In quality products, this indicator is in the range from +110°C to +130°C. In cheap ones, it can be lower - up to 90 ° C (and in fact 70-80 ° C). If your system is designed as a low-temperature one, this is not scary, but if there is a solid fuel boiler, the temperature to which the coolant can be heated is very important.

It is worth paying attention to maximum pressure at which the pump can operate. In the heating system of a private house, it is rarely higher than 3-4 atm (this is for two-story house), and normally is 1.5-2 atm. But still, pay attention to this indicator.

What else to pay attention to is the material from which the case is made. The optimal one is cast iron, the cheaper one is made of special heat-resistant plastic.

Connection type and size. The circulation pump can be threaded or flanged. The thread can be external and internal - appropriate adapters are selected for it. Connecting sizes can be: G1, G2, G3/4.

It is also worth paying attention to the presence of protection. May be dry run protected. In circulation pumps with a wet rotor, it is very desirable, since the cooling of the motor occurs due to the medium being moved. If there is no water, the motor overheats and fails.

Another type of protection is overheating protection. If the motor heats up to a critical value, the thermal relay turns off the power, the pump stops. These two features will extend the life of the equipment.

Manufacturers and prices

Name	Performance	pressure	Number of speeds	Connecting dimensions	Max working pressure	Power	Housing material	Price
Grundfos UPS 25-80	130 l/min	8 m	3	G 1 1/2"	10 bar	170 W	Cast iron	15476 rub
Caliber NTs-15/6	40 l/min	6 m	3	external thread G1	6 atm	90 W	Cast iron	2350 rub
BELAMOS BRS25/4G	48 l/min	4.5 m	3	external thread G1	10 atm	72 W	Cast iron	2809 rub
Gileks Compasses 25/80 280	133.3 l/min	8.5 m	3	external thread G1	6 atm	220 W	Cast iron	6300 rub
Elitech NP 1216/9E	23 l/min	9 m	1	external thread G 3/4	10 atm	105 W	Cast iron	4800 rub
Marina-Speroni SCR 25/40-180 S	50 l/min	4 m	1	external thread G1	10 atm	60 W	Cast iron	5223 rub
Grundfos UPA 15-90	25 l/min	8 m	1	external thread G 3/4	6 atm	120 W	Cast iron	6950 rub
Wilo Star-RS 15/2-130	41.6 l/min	2.6 m	3	internal thread G1		45 W	Cast iron	5386 rub

Please note that all specifications are for moving water. If the coolant in the system is a non-freezing liquid, adjustments must be made. For relevant data for this type of coolant, you will have to contact the manufacturer. Similar characteristics could not be found in other sources.

The circulation pump is a key figure in modern heating systems with forced circulation of the coolant. Its use eliminates the need to install the boiler at the lowest point of the room and makes it possible to use small diameter pipes with an arbitrary location of the line. In addition, the introduction of a circulation pump into the circuit increases the heating performance and reduces energy costs. The service life of the unit directly depends on the correct installation and compliance of the technical characteristics with the hydraulic parameters of the heating system. We will understand the intricacies of pump designs and the nuances that you need to pay attention to when choosing a device.

Circulation pumps for heating systems

The pump for heating systems consists of a cast type housing, a ceramic or steel rotor with a plastic or light-alloy impeller (impeller), a stator installed in a casing, and a terminal box with an adjusting device.

When the electric motor rotates, the impeller throws the coolant to the outer edge of the volute made in the housing. Further movement and injection of the working fluid occurs due to centrifugal force. At the same time, a vacuum occurs at the inlet pipe of the pump, which contributes to the absorption of a new portion of the coolant.

The design of the circulation pump is typical for centrifugal units, but at the same time it has many interesting design solutions.

Design of pumps for heating systems

Depending on the design, all pumping units of heating systems are divided into two types:

• dry circulation pumps;
• wet rotor pumps.

Both types of devices are quite effective in heating pipelines and have both advantages and disadvantages.

Dry type pumps

In devices with a dry rotor, the electric motor is placed outside the pump housing

In such units, the rotor does not come into contact with the working fluid, since all elements of the electric motor are separated from the working chamber of the device by a sealing system of a special type. It consists of polished, carefully fitted metal rings. To eliminate friction, a thin film of liquid is constantly present between the sealing elements, which acts as a lubricant. It is she who prevents damage to the seal rings.

Depending on the location of individual structural elements, dry pumps of heating systems can be divided into three types:

• console type pumps;
• vertical centrifugal pumps;
• block pumps.

The suction pipe of cantilever circulation pumps is located on the outer edge of the volute, while the discharge part is placed in opposite side. A feature of the units of the second type is the location of the electric motor in a vertical plane, which can significantly increase the performance of the devices.

The device of the circulation pump with a dry rotor

Dry rotor pumps have numerous advantages:

• long term operation;
• high performance;
• Efficiency is close to 80%;
• the ability to work with a coolant leak;
• high maintainability;
• relatively low cost;
• reliability;
• Possibility of mounting in any position.

At the same time, the increased noise level of units of this type does not allow them to be installed in residential premises. The disadvantages also include the requirements for the cleanliness of the coolant and the need for periodic maintenance and lubrication of the movable seal.

Glandless circulation pumps

The advantages of wet rotor circulation pumps have opened up wide prospects for their use in autonomous heating systems.

Rotor and Working wheel pumps of this type are in a pumped coolant, which does an excellent job not only with its main function, but also with cooling the parts of the electric motor. The pump motor stator is separated from the rotor by a hermetic cup made of non-magnetic steel or carbon fiber. Wet type units are designed to operate in systems with a stable, rarely changing fluid flow. The presence of a control unit allows you to vary the number of connected windings, and accordingly, change the pump performance. The choice of the optimal operating mode has a positive effect on the efficiency of the unit.

The advantages of "wet" type units include:

• low noise level;
• no need for lubrication;
• efficient cooling method;
• ease of maintenance and installation;
• relatively low price unit and spare parts;
• long service life.

Pumps with a wet rotor are not without disadvantages in the form of low efficiency (a little more than 30%), the inability of the unit to work without a coolant, and the requirements for the horizontal orientation of the rotor shaft during operation.

Design features by connection method

Flange connection is most often used in high power pump models

In the pipelines of municipal and industrial highways, circulation pumps with a dry rotor are most often used, as more productive and powerful devices. Their connection is carried out mainly by a flange connection, and both a common support frame and a specially equipped foundation can be used for installation. At the same time, manufacturers also produce devices designed to be built into autonomous systems heating. As a rule, they all have increased power and performance, and their installation does not require special fastening.

The delivery set of pumps with a coupling type of connection necessarily includes fasteners

Coupling connections of circulation pumps are typical for low-power wet-type units with direct-flow movement of the coolant, which can be built directly into the pipeline. Such devices are represented by a wide range of household centrifugal pumps, while powerful industrial units with a flanged connection require additional fastening of the pipeline using a console and foundation.

Criterias of choice

The efficient operation of the heating system is directly related to the performance of the circulation pump and the pressure at its outlet.

If the power of the unit is low, an insufficient amount of coolant will be pumped through the system, which will make it impossible to reach the required temperature.

In addition, when used in everyday life, important factors influencing the choice are the noise level (which depends on speed) and the efficiency of the unit's electric motor. Correct selection the heating system pump requires thermal and hydraulic calculations, on the basis of which the optimal technical characteristics are determined.

Selection and installation of circulation pumps for heating systems (video)

Required performance

Before proceeding to determine the performance (flow rate, volumetric flow) of the circulation pump, calculate the amount of heat required to heat the room in the coldest time of the year. To calculate this parameter, there are special formulas that include both the physical parameters of the room and possible heat losses. We propose to use a simplified calculation method applicable for middle lane our country. It lies in the fact that the required amount of heat to heat 1 sq.m of the area of ​​​​the room is 100 watts. Therefore, to determine the required amount of thermal energy, the total area of ​​\u200b\u200bthe premises in the house or apartment should be multiplied by 100. For thermally insulated buildings, this parameter is reduced by 25 - 30%.

P - required thermal power, kW;

Tf is the temperature on the supply side, ºС;

Tr is the temperature in the return line, ºС.

For example, for a house with a total area of ​​80 sq.m., with a temperature of the heat carrier at the outlet of the boiler of 70 ºС and in the return pipeline of 50 ºС, the flow rate will be at least Q=8×0.86/(70-50)=0.34m3/h.

Calculation of the required pressure

The next step in choosing a pump is to calculate the supply pressure of the coolant. This characteristic determines how easily the unit can overcome the hydraulic resistance of the liquid in the pipes of the heating system. The pressure value is calculated by the formula:

H=1.3×(S1×L1+S2×L2+Z1+Z2+…Zx)/10000, here:

S1, S2 – pressure losses in the pressure and return lines, Pa/m;

L1, L2 - respectively, the length of the supply and return branches, m;

Zx - individual resistances of pipeline sections, Pa.

Table of hydraulic resistance values ​​for various pipeline parameters

Values ​​for calculations can be taken from technical data sheets for equipment and structural elements of heating systems or from special tables. For a simplified calculation, you can use the following values:

• resistance of straight sections of pipes - from 100 to 150 Pa / m;
• losses on fittings are up to 30% of the resistance in straight sections of pipelines;
• resistance on thermostatic valves adds up to 70% more of the calculated value.

Pressure losses at nodal points of heating systems

Having received the values ​​​​of volumetric flow and pressure, the required model of the circulation pump is selected from the catalog.

Engine power

An important characteristic of a centrifugal pump is power, since it is this parameter that affects how much electricity its electric motor will consume. Modern devices are equipped with a step adjustment system, which helps to choose the most optimal mode work.

The consumption of household circulation pumps is minimized and comparable to a small electric lamp.

In addition, manufacturers are constantly working to improve the energy efficiency of the units. For this purpose, a single classification for this parameter has been introduced. For example, the consumption of class "A" appliances is no more than 6 W, which will require a little more than 90 kW / h of electricity per year. The power of the circulation pump, as well as the strength of the current consumed, is indicated in the technical data sheet for the product and is duplicated in the plate located on its body.

Noise level

The specifics of the use of modern circulation pumps in living conditions forces manufacturers to resort to non-standard solutions to reduce the sound pressure level. So, to reduce the cavitation that occurs during the operation of the unit, blades and channels of an optimized shape are used, and the pump casings are massive structural elements. In addition, the rotating parts are placed in a liquid, which also contributes to quiet operation. Most often, the noise level of the unit does not exceed 45 dB when operating at the highest speeds. If the regulator is set to the minimum level, then it is almost impossible to hear the sound of rotating elements.

Difficulty in installation and operation

For long and reliable operation centrifugal pump heating system, it is important to install it correctly. Previously produced models were recommended to be mounted on the return heating branches due to the lower temperature of the coolant, and, accordingly, better cooling of the device's electric motor. Modern units are made of high-strength, heat-resistant materials, so such restrictions on this moment removed. At the same time, manufacturers require that the pump be installed only in positions in which the rotor shaft will occupy a horizontal orientation in space. An important factor affecting the service life of the product is the absence of air in the pipes of the heating system. Therefore, the installation of expansion tanks and Mayevsky taps is mandatory.

During installation, a bypass line is required for the operation of gravity heating systems in the event of a pump failure. At the same time, shut-off valves are mounted on both sides of the pump. Ball Valves, and a coarse filter is installed on the side of the boiler and check valve. This scheme increases the service life of the unit and increases the reliability of its operation.

During operation, the pump does not require maintenance. The only thing that may be required when turning on the device is to turn the rotor to facilitate its start and remove air from the working chamber. To do this, there is a special plug on the body of the device, and a groove for a screwdriver is made on the rotor shaft.

Starting the pump and removing air from its working chamber (video)

Thanks to an agreement between manufacturers of centrifugal pumps, their marking has been unified and has the following features:

• the first digits after the brand of the unit indicate the connecting diameter of its nozzles;
• the next number characterizes the magnitude of the pressure.

For example, the designation WILO 25-60 indicates that the unit manufactured by WILO is designed to be connected to 25 mm or 1 ″ spurs, and its head is 6 m or 0.6 atm. Information about the pump model is contained on a plate placed on the device case. In addition, it includes data on current consumption at various modes work.

Marking of circulation pumps

Manufacturers and prices

There are many manufacturers of circulation pumps on the market. Excellent quality and technical specifications have units of German Grundfos. The cost of low-power devices from their model range starts from 6600 rubles for the UPS 25-40 model and exceeds 19000 rubles for the UPS 32-80.

The products of another German brand WILO have an excellent price / quality ratio. So, for a product with parameters 25-20, you will have to pay from 5990 rubles, while the cost of a powerful pump with a head of 80 m is almost 11 thousand rubles. As you can see, compared to Grundfos, the difference is significant.

More budget solutions can be found in the line of models of the Italian company DAB and Pedrollo, the price of which is reduced by about 25% compared to their German counterparts. From inexpensive products, we can distinguish products under the brand name SPRUT made in China. The LRS 25-40 pump can be bought for only 1800 rubles, while for the most powerful LRS 32-120 you will have to pay no more than 9 thousand rubles. The only problem is the build quality and components of products from China.

The choice of a centrifugal pump determines how reliable and efficient the heating will work. Therefore, we need exact calculation all parameters, taking into account the specific features of piping. Correct installation unit affects the service life and performance, therefore, during installation, it is necessary to strictly follow the recommendations of the equipment manufacturer. Only in this case the pump will be able to work long time delivering comfortable warmth to every corner of your home.

Thanks to my versatile hobbies, I write on various topics, but my favorite ones are engineering, technology and construction. Perhaps because I know a lot of nuances in these areas, not only theoretically, as a result of studying at a technical university and graduate school, but also from the practical side, since I try to do everything with my own hands.

Circulation pumps used to pump water or a thin homogeneous liquid are an important part of the heating system. Providing uniform motion coolant through pipes, they achieve uniform distribution heat, improving performance.

In addition to ensuring the movement of fluid in a circle inside the heating pipes, the pump can operate in recirculation mode. When calculating its parameters, they try to take into account friction losses and resistance of the coolant. The height of the top point, piping, heating appliances have little effect on the operation of the pump, because the liquid supplied to the pipeline in one direction pushes it in the opposite direction. Therefore, when selecting a circulation pump, you can stop at a lower power to ensure the normal movement of the coolant.

Calculations

The device of a circular pump is a mechanism in the form of a rotor placed inside metal case. A wheel with several blades (impeller) is fixed on the rotor shaft. When the pump motor is turned on, the wings rotate and move the liquid throughout the heating system.

The principle of operation is the forced transportation of water inside closed loop heating systems, in other words, ensuring the circulation of the coolant through pipes and radiators. Proper selection of such a unit ensures its correct operation without unnecessary costs.

Pump power calculation table.

Before choosing a pump, it is necessary to determine the volume of water that will pass through the heating boiler in one minute. It is these parameters that manufacturers lay down, equalizing the flow rate of the liquid with the power of the boiler. If a heater of 20 kW is installed, then in one minute it will pass 20 liters of coolant.

Next, it is necessary to calculate the water flow in each ring of the heating system (knowing the power of the radiators, this process is not difficult). The flow rate of the coolant in the pipes directly depends on their diameter. Inch pipes transport 30 liters of liquid per minute, two-inch - 170 liters / min. The average speed of water movement along heating system equal to 1.5 m/s. The power of the circulation pump can be selected according to the length of the pipeline. For a ten-meter section of the heating main, a pressure of 0.6 m is sufficient. Therefore, in order to establish a water supply through a 100-meter heating system, it is necessary to select a pump capable of delivering a pressure of 6 m.

You can also calculate the power using the following formula:
Qpu=Qn/1.163xDt [m3/h], where

• Qpu (measured in m3/h) - coolant supply at the design point;
• Qn (measured in kW) - consumed heat in the heated area;
• Dt is the temperature difference in the forward and return pipelines (average 10-20 °С);
• 1,163 – specific heat water.

Such calculations are not absolute, they are rather standard. There are complex formulas for more accurately determining the required power of the circulation pump, but it will not be easy to understand them without certain knowledge in the field of physics. Yes, and the units are mass-produced, so it is possible to adjust their operating parameters to individual heating systems only approximately. Therefore, experts advise to select a pump with a power reserve of 5 - 10% of that which was obtained as a result of calculations. There are devices with several settings. During operation, you can choose optimal parameters work.

Possessing such simple knowledge and enlisting the help of the seller, you can choose the circulation pump of the optimum power at which heat will be provided throughout the room.

Kinds

The fluid pressure is created by rotors on which the blades are fixed. More often, one rotor is involved in the design of the circulation pump for heating, but you can find an option with two. An important condition operation is the absence of air in the system.

According to the device, the execution of the working part, the pump can be with a wet rotor or dry. Those with a wet rotor are specially designed to be in the pumped medium with the impeller. Changes often affect the design of the housing, made in such a way that liquid enters through the existing technological gaps, its constant movement cools the motor, lubricates moving parts.

Circulation pumps equipped with a wet rotor do not have an oil seal, a sliding mechanical seal. The rotor is completely in the pumped medium, which provides cooling and lubrication of parts. As the rotor rotates, water constantly passes through the sleeve. best effect observed if the pump is horizontal, then no air pockets are formed inside the wet rotor.

The fact that all parts of the heating circulation pump are constantly in the liquid not only lubricates the moving parts, but also absorbs vibration noise, so they are practically silent. To check its operation and the correct rotation of the rotor, use special device or visually by opening the back plug. The absence of noise during operation allows them to be widely used for individual heating. In addition, the execution of the design of pumps equipped with a wet rotor can be ordinary - for heating systems, and special - for water supply. hot water where the possibility of mineral deposits is taken into account.

In such cases, the liquid does not wash the rotor, does not lubricate the moving parts. The main advantage of this type is the ability to pump a larger volume of liquid. The advantage is manifested in the installation of engines of greater power. In addition, the device comes with a solid shaft, on which a motor with impellers or with a coupling connection is installed - here it is possible to replace the electric motor, install another one with larger parameters.

To prevent water ingress, a mechanical seal, an oil seal is installed between the pump and the electric motor. During rotation, a thin water film appears between the surfaces. Due to the pressure created inside the pump, the film additionally seals the rotating parts. The main material in the manufacture of rings is agglomerated coal, sometimes under difficult working conditions, the seal is made of ceramics, stainless steel.

According to the design of the execution, the device of the circulation pump is with a flange connection of the motor and a coupling. If the branch pipes (suction, pressure) are located on the same axis, then this is a direct-flow version, which allows their installation directly in the line. A frame is provided for mounting. In addition to fastening to the frame of the pump, electric motor, it itself is installed on the foundation.

Why is it necessary

The heating circuit with a circulation pump eliminates some of the problems that are typical for the natural type of coolant movement. After all, if the water at the outlet of the radiator is cold, when it also reaches the extreme radiators, it is also barely warm, then it enters through the return cold water makes the boiler work at the maximum of its capabilities. At the slightest design miscalculations, installation errors, the distortion in temperature becomes even more noticeable, especially when it is necessary to warm up the room quickly, or when the system is first started, which can be seen from the operation of the boiler, from distant registers.

The use of a circulation pump eliminates these disadvantages. First of all, the requirements for compliance with pipe slopes, their flow area are reduced, all plugs caused by temperature differences are eliminated. The heat transfer occurs evenly, the temperature of the coolant at the inlet / outlet of each radiator is almost the same, and the difference between the coolant before entering the system and returning it to the boiler is several degrees, within ten.

The pump greatly simplifies the design of the piping system.

What does it give? Stabilizes the boiler. If the difference is several degrees, then a smaller volume of gas is spent on heating, the duty cycle is reduced. For example, we need a coolant temperature of 70. Initially, when the water is cold, the boiler operates at maximum power, but as it warms up over time, the picture changes.

In the spring and autumn months, when the house is slightly cool at night and comfortable during the day, the combined operation of the boiler, automation, circulation pump can maintain the coolant performance within 40 °, which is impossible with natural circulation.

The coolant returns in one pass through the system, having lost only 5 °, its temperature is 65 °, while it is the same in the rooms, the heat is distributed evenly over all radiators, and the automation turns off the burner according to the programmed indicators.

The next switch on will occur when the temperature drops. This is an economical mode of operation, in which there is no constant heating, but only the maintenance of the required temperature parameters. If thermostats are installed on all radiators, then by setting the necessary temperature parameters on each register, for example, in the kitchen, in a warm room on the south side, lowering them, we will get additional savings.

Additional Benefits

When using a heating circulation pump, a decrease in the diameter of the pipes being laid is allowed. This is manifested in additional cost savings, allows you to reduce the volume of water in the system, respectively, the volume of gas is reduced to maintain desired temperature, heating time is reduced.

grundfos pump.

But there are a number of parameters that make adjustments to the calculations. The main ones are: the area of ​​\u200b\u200bthe house (usually residential is taken into account), the thermal conductivity of materials, the friction of the liquid inside the pipes. The last requirement, given the fluidity of the liquid, may seem unreasonable, but it works. The automatic control option installed on the circulation pump will allow you to heat the house before your arrival, the cottage before the weekend, and significantly save electricity. When buying a product, do not forget to pay attention to the warranty, service life.

There are several major manufacturers of pumping equipment that have long proven themselves in terms of quality and reliability. These are the brands Grundfos, DAB, WILO, Pedrollo. The main difference in their work is the maximum implementation of production automation processes, which, affecting many stages, allows you to get high-quality products.

Glandless circulation pumps for heating, ventilation, air conditioning.

This type of pump is mainly used for one- or two-pipe heating systems and in mixing circuits of large systems.

Glandless circulation pumps are distinguished by:

ease of installation;

high operational reliability;

built-in thermal protection;

low noise level;

profitability;

absence of necessity Maintenance

Circulation pumps Grundfos series UPS / UPSD are equipped with step changeable rotation speed. Circulation pumps of the UPE/UPED series are regulated electronically. The UPS and UPE circulation pumps are single pumps, the UPSD and UPED pumps are a twin model. Circulation glandless pumps Grundfos (UPS, UPSD series 2000)

Grundfos pumps frequency controlled (UPE, UPED series 2000)

Types of circulation pumps

The two most common types of circulation pumps are dry and wet rotor pumps.

Circulation pump with "dry" rotor

This type includes traditional console, monoblock, as well as Inline pumps. The latter are equipped with a sliding mechanical seal, which consists of two very finely polished rings. When the pump is turned on, the rings begin to rotate relative to each other. Between the sliding surfaces is a thin water film. Given that the rings are pressed against each other by a spring, when the seal wears, it self-adjusts. This provides the pump with guaranteed tightness.

Depending on the type of coolant and its temperature, graphite, ceramics, stainless steel, tungsten carbide, aluminum oxide and other materials. In many ways, they ensure the long service life of sealing rings - when pumping ordinary water into normal conditions operation, they do not require any maintenance for 3-4 years. In comparison, traditional gland packing does not provide proper tightness, requires water supply for lubrication and cooling, and also needs regular maintenance.

Wet rotor circulation pump

Circulation pumps with a "wet" rotor appeared a long time ago, in the early fifties of the last century. In countries where district heating is not widespread, they have become quite widespread. Naturally, in a "wet" pump, the rotor, together with the impeller, is immersed in the pumped liquid. It lubricates the shaft bearings and at the same time cools the motor. The tightness of the energized part of the engine is ensured by a separating cup made of stainless non-magnetic steel. The rotor shaft is often made of ceramic, bearings are made of ceramic or graphite. The pump housing for heating systems, as a rule, is cast from cast iron. For hot water use models with bronze or brass cases. In a word, everything is done to ensure the long-term and stable operation of the unit. To this characteristic it should probably be added that the "wet" type pumps operate almost silently and do without maintenance for many years. Their installation, repair or replacement does not require such labor-intensive operations as, for example, centering. But this "circulator", unfortunately, has a serious flaw: the efficiency of its work does not exceed 50 percent, while for its "dry" counterparts this figure can rise to 80 percent. Therefore, it is more in demand in small heating and hot water systems.

Grundfos in-line circulation pumps for industrial applications.