How to choose a smoke exhauster for a solid fuel boiler - types, differences

How to install a smoke exhauster

If you have a need to install a smoke exhauster on a chimney, which cannot be removed or disassembled, and it is impossible to install a pump inside the room, then you have to install it outside. Although the best option for an electric motor is indoor installation. Smoke exhausters are usually sold with an impeller, impeller and electric motor with a boiler or pipe mount. It is necessary to choose a suitable exhauster, taking into account it:

• Dimensions;
• Power;
• Connection diagram.

When there is a smoke exhauster and there is a chimney pipe, you need to figure out how to connect it all together. Most often, the engine is attached to a makeshift snail. And the snail is welded (attached) directly into the chimney. The connection slot must be equipped with a flap so that it can be opened or closed. Based on specific weather and other conditions - using natural or forced traction.

In principle, there is nothing complicated and supernatural in installing this device, and any home craftsman can handle it. Everything can be done with an ordinary grinder and drill at home. It is advisable to make a preliminary drawing of the connection, which will indicate the dimensions and diameters of the branch pipes and the main pipe. For example, if your chimney pipe is 159 mm, then the outlet from it for the smoke exhauster can be 110 mm in diameter.

Varieties

According to their functional purpose, there are three main types of smoke exhausters:

1. The natural draft amplifier is a fan.
2. Flow-through smoke exhauster.
3. Traction centrifugal machine.

The fan is installed at the end of the hood. It blows air in a natural way. A flow-through exhaust fan is also mounted at the outlet. But all its elements are taken out, therefore you can use such a device as needed.

Centrifugal equipment is rightfully considered the most rational, since it is possible to achieve high pressure in the impeller. Unlike a flow-through device, a centrifugal one can serve as an effective traction device, and not just an exhaust amplifier.

The smoke exhausters can be left-handed and right-handed. It can be installed vertically and horizontally.

Good draft is the result of correct calculation and installation of the chimney

When asked which chimney is better for a coal boiler, and which one is better for a diesel boiler, etc., the correct answer will always be different. Because a chimney made for a wood stove may be completely unsuitable for a gas boiler, for example. And there may be several reasons for this. At the same time, few people are able to lay out a new capital chimney instead of an ineffective one. That is why the existing chimneys have to be improved in one way or another. Often, the improvement involves the installation of a smoke exhauster for a new domestic boiler.

Everywhere, the chimney for a solid fuel boiler is made capital brick. If it has sufficient height and cross-section, then it always has excellent traction and no amplifiers of air movement are required. But there are also exceptions. For example, a brick chimney for a stationary solid fuel boiler cannot be brought to the required height. As a rule, a chimney for a solid fuel boiler is elementary made by hand, but it does not always do an excellent job with its function. And it often happens that additional traction must be provided using smoke exhausters for household solid fuel boilers, purchased or made by hand.

From what and how to lay out the chimney so that it effectively copes with the removal of smoke, this is a topic for a separate large article, and now we will not touch on it. A solid brick chimney is good for a solid fuel boiler or stove, but without additional inserts it cannot be used for modern boilers for other types of fuel. For example, a boiler smoke exhauster may be needed if the chimney was installed incorrectly from the very beginning.

How to make the correct connection to the chimney for a conventional solid fuel boiler? Highly qualified specialists know about this, but they are also mistaken, not noticing some local trifle in time. A good smoke exhauster for a solid fuel boiler or any other is able to eliminate all errors in the design and construction of boilers and chimneys. Especially if the chimney for the boiler is not brick, but metal.

This is a whole science - the device of a chimney for a solid fuel boiler. What can we say about more complex options for heating devices. Therefore, errors are often encountered, even simple brickwork is rarely ideal. Compliance with all technical standards for aerodynamics is still a challenge! And how to make a chimney if a brick boiler will be connected to it? Will your chimney be effective enough for a solid fuel boiler? Questions like these are often impossible to answer in advance.

Choosing a smoke exhauster

Forced air supply depends on the type of boiler. For efficient operation of the heater, the smoke exhauster must fully meet the nominal requirements and, in terms of its technical parameters, correspond to the characteristics of the boiler.

If it is powerful, then a centrifugal traction machine capable of creating high pressure should be chosen as an air blower. Boilers that have an average power can be equipped with instantaneous smoke exhausters so that they additionally supply air to the furnace. If the boiler is low-power, a fan installed at the outlet is used.

An important role for the choice of a smoke exhauster is played by the type of solid fuel used. Firewood burns out much faster than coal. For a boiler, in the firebox of which wood material will burn, you can limit yourself to a flow-through exhaust fan or a fan.

If the boiler is fired with coal, the draft must be stronger so that all the fuel can burn out. After coal, combustion products are formed in greater quantities than after firewood. To effectively discharge them into the chimney forcibly, the chimney must be powerful enough.

The use of smoke exhausters of any type of design allows you to fully realize the functions of the heater, avoid smoke and organize a sufficient supply of air to the boiler furnace. In this case, there is a complete burnout of the fuel, the removal of volatile products and ash outside the premises.

What is better smoke exhauster or blower

When the traction turbine is integrated into the heat generator by the manufacturer, such questions do not arise. Adding an exhaust fan to a conventional direct fired boiler is another matter. It must be understood that in this case the smoke exhauster solves only one problem - creating a vacuum in the furnace and increasing the draft. There are a number of negative points here:

1. Without an electronic control unit, performance will have to be adjusted manually. Automatic maintenance of the coolant temperature is excluded.
2. When air is supplied through the open ash chamber door, the fan will force the boiler to operate at maximum. Setting up a long burn mode will not be easy.
3. In the event of an emergency stop of the impeller, fuel combustion will not stop, since the gases freely pass through the volute or the smoke exhauster housing. Air enters the firebox, the probability of overheating increases.
4. The impeller and the inside of the unit are covered with soot, which must be removed. The sticking speed depends on the moisture content and resin content of the wood.

The blowing machines always work in conjunction with the controller, so there are no problems listed above:

• the blower changes the capacity and turns off at the command of the control unit, the coolant heats up to the set temperature;
• during combustion, the ash pan door is hermetically closed, air is supplied through a separate channel;
• in the event of a power outage, the air channel is automatically closed by a gravitational flap;
• the impeller blades do not come into contact with hot smoke and soot.

Now let's compare the cost of a traction and blower fan, excluding the price of the controller. An exhaust fan for a TT-boiler up to 30 kW will cost 90 cu. e., supercharger - 60-65 cu. e. The difference is due to the design features of the exhaust unit - hot gases should not overheat the electric motor, plus the impeller is made of metal (when pressurized, it is made of plastic).

In terms of the complexity of the installation, the units are approximately the same. Installation of a pumping snail involves cutting out an opening in the ash pan door, a smoke exhauster - disassembling or cutting out a pipe. It is easier to install a roof hood, but you have to pull a long cable.

Fan for solid fuel boiler

According to the parameters and functional characteristics, fans for solid fuel boilers are divided into the following types:

• devices with electrically commutated motors (EC);
• fans equipped with synchronous motors;
• asynchronous motor blowers.

Each type has its own advantages and disadvantages:

1. Electrically commutated motor. This device is able to independently change the number of revolutions, having previously received a corresponding signal from the control unit, and also has a wide range of fan operation adjustment. However, the device also has a number of disadvantages - it is not compatible with most of the temperature regulators produced by domestic manufacturers, and besides, this technique has a high price.
2. Fan with synchronous motor. The device is simple to manufacture and has a low price. But this type of fan also has a number of disadvantages. For example, a small adjustment range and minimum torque during start.
3. An induction motor has many advantages. First of all, it is simple and easy to use. Secondly, it has a reliable design. However, there is also a drawback - high starting currents.

To remove smoke, smoke exhausters are used, which can be read about on this page.

Device

Any blower fan, regardless of which country it is produced in, consists of a metal case, and inside it there is an electric motor

Also, an important part of the blower fan is the blades, which are protected by a safety grid. The structure of the device is not complicated, but at the same time reliable

This is ensured by its robust housing, high operating temperature and reliable motor manufacturer. Vulnerable elements and parts are protected by a grill. The blower fan is lightweight, so there are no installation problems.

Fan for solid fuel boiler

On the Russian market, you can find fans for solid fuel boilers from the following manufacturers:

1. Pressure centrifugal fan (turbine) WPA of various modifications. Manufacturer - Polish company MplusM. This company specializes in the production of turbines for solid fuel boilers. The model is in stable demand in the Russian market, as it is characterized by high quality and good reliability.
2. NWS fan of various modifications. Production - Nowosolar (Poland). Purpose - forcing air into the combustion chamber. This increases the efficiency of burning fuel in the combustion chamber.

https://youtube.com/watch?v=8ZVXK4JcCNQ

How to choose the right

The performance of a solid fuel boiler is largely determined by a properly selected fan. What does this mean?

Let's consider several situations:

1. If a fan is installed that supplies a lower volume of required air, then the fuel will not be burned completely. As a result, the boiler power decreases and the rated temperature is not reached.
2. If a fan is installed that supplies a larger volume of the required air, then the solid fuel boiler will quickly gain temperature, and the fan will constantly turn on and off. As a result, fan breakdown is inevitable, the chimney will be constantly hot, and heat will go through it.

There is only one way out - to choose the right blower fan.

The table shows options for installed fans on solid fuel boilers of various capacities.

Benefits

Fireplace fan a smoke exhauster for a fireplace is needed in rooms where:

• the smell of burning is constantly present;
• narrow chimney;
• chimney too low.

This device perfectly solves these problems. In addition, this device has many other advantages:

• high power;
• economy;
• resistance to seasons and weather conditions;
• light weight;
• lack of noise;
• ease of installation;
• ease of further maintenance.

Thanks to this design, the life of the fireplace is increased. The work of the smoke exhauster for the fireplace does not depend on the type of fuel.

Device application

It is important to synchronize the operation of the boiler and the fan during operation. Installing a smoke exhauster on a boiler without a control and automation unit is excluded, so you will have to buy and install all the electronics entirely from scratch.

Such fans are indispensable in the following situations:

• strong smoke in the room due to the opening of the firebox door, which can be facilitated by the design feature of the boiler;
• holes and cracks form in the brick chimney, so smoke is sucked through them;
• draft problems - complex chimney design, strong winds and other problems;
• insufficient chimney height.

How to install a smoke exhauster

Strengthening traction with a smoke exhauster also has a reverse side. If the natural pressure does not increase for a certain time after the fan has been running, then it is impossible to turn off the smoke exhauster, since asphyxiation by carbon monoxide can be a possible consequence. If the electricity is cut off at night, smoke will enter the room, and this cannot be avoided. While the chain thermostat closes the damper, the entire boiler room will be in smoke

In this regard, it is very important to do good natural cravings in order to avoid the occurrence of such cases.

Sources of

• https://teplofan.ru/sistemy-otopleniya/komplektuyushhie/ventilyator-kotla
• https://RSVgroup.ru/ventilyatsiya/dutevoj-ventilyator-dlya-kotla.html
• https://oventilyacii.ru/kondicionirovanie/kak-sdelat-dymosos.html
• https://svoimi-rykami.ru/stroitelstvo-doma/pechi_i_mangaly/ventilyator-dlya-kotla-svoimi-rukami.html
• https://klimatlab.com/otoplenie/tverdtoplivo/dymosos-dlya-tverdotoplivnogo-kotla-svoimi-rukami.html

Why do you need

The smoke exhauster, as the main unit for quickly removing smoke in the room, is recommended to be installed not only when the existing natural ventilation cannot effectively cope with the task.
It allows you to:

• significantly increase the efficiency of a heating device (solid fuel or gas);
• to reduce the consumption of fuel used in one load;
• to reduce the number of pipe cleaning from deposits - soot and tar;
• to minimize the likelihood of smoke and burning entering the premises;
• get rid of the characteristic unpleasant odor that occurs during the operation of the heating device.

Device

The smoke exhauster is a constructively simple device. It consists of several nodes, each of which has its own purpose.

1. Housing.
2. Suction pipe or suction pocket of the exhauster.
3. Guiding apparatus. There are right and left rotation, which is determined by the direction of the fan blades.
4. Working wheel.
5. Frame.
6. Electric motor.

The body is made in the form of a "snail", which provides the required swirl of the air entering the unit. Made of heat-resistant steel, covered with thermal insulation.

The smoke exhauster guide device is located on the suction branch pipe, it allows you to regulate the air pressure using a swivel mechanism that unites the fan blades. Each blade is curved to allow the air flow to rotate in the same direction as the rotor. With the help of the rotary mechanism, it is possible to block the lumen of the nozzle to some extent.

The smoke exhauster impeller is a unit on which the fan blades are located. They are attached to it by welding or rivets. A rarefied atmosphere is created in the central part of the wheel when it rotates. For this reason, incoming air is drawn in here. Such small-sized devices as smoke exhausters for fireplaces work in a similar way.

The wheel docking unit can be located on the engine shaft or on the intermediate shaft, depending on the design of the unit. If it is a dust collection equipment, special filters with absorbents are included in the device. This is how all fire-fighting units are equipped. Ash collectors can be included in the design of boiler apparatus. The smoke exhauster device determines its purpose.

On the impeller, holes can be located, which are necessary for fixing the blades in a given position. Balancing can be done manually or by an electrical actuator. The direction of rotation of the fan blades can be distinguished by looking at the unit from the side of its electric motor. The axial guide device of the smoke exhauster ensures the rotation of the blades, regardless of their number and direction of the slope, at an angle from 0 to 90 °.

The blower fan and the smoke exhauster have a similar design, but differ in purpose. Devices of the first type provide air injection into the boiler furnace. The latter are designed to remove fuel combustion products and release them into the atmosphere outside the boiler room.

Fans and smoke exhausters of boiler installations have the same principle of operation, they can be left- and right-handed, with direct and reverse draft. These machines are designed for long-term, trouble-free operation over a temperature range of 0 ° C to +250 ° C. Fume exhausters are marked as "D" and "DN", fans - as "VDN". The latter are produced with the impeller landing on the motor shaft.

Repair of smoke exhausters and fans is carried out by persons who have passed the appropriate certification and instructed on the safety of the operation of electrical appliances.

Purpose of the smoke exhauster

The smoke exhauster for a solid fuel boiler is a household and industrial device. It provides constant thrust and allows you to control the fuel combustion process. Installation of a smoke exhauster for a stove is necessary for several reasons:

• due to high-quality draft, smoke from the firebox does not penetrate into the boiler room through the cracks, as well as when the door is opened;
• the possibility of installing a heating system in the absence of traction;
• implementation of control over the amount of fuel burned and the intensity of combustion by means of traction control.

There is such a variety of equipment as smoke exhausters, dust extractors and firefighters. The first ones perform the function of cleaning the outgoing flue gases. The latter provide air purification from combustion products during fires and have the function of supplying fresh air (not all models).

There are devices for removing aerosols, fine powdery suspensions, gases. The most powerful units are able to provide air purification within a few seconds. Such machines are equipped with a system of filters that absorb combustion products and other substances that enter them. Fire smoke exhausters can be small-sized and large-sized (trailed).

What is a fireplace smoke exhauster, and why is it needed

This device is a duct fan with an electric motor, which is mounted at the outlet of the chimney.The principle of operation of the device is simple - during the operation of the fan, the draft in the chimney increases.

Simply put, this device is a forced exhaust system, but they are not designed for full exhaust. They are used only to improve the (episodic) natural draft in the pipe, or during its repair.

Chimney hoods

For example, a chimney smoke exhauster is started as needed - at a time when the natural draft drops to a certain value.

When should you use it?

There are several indications for the use of a chimney smoke exhauster, which in one way or another are associated with impaired draft in the chimney.

Indications for use:

1. When there is no draft in the chimney at all (for example, due to errors in the construction of the chimney, or because of its weakness in terms of exhaust). This often happens when the chimney height is incorrectly selected.
2. In cases where the chimney is incorrectly positioned relative to the roof ridge.
3. If a higher building was built nearby and, accordingly, the thrust fell because of this (due to the obstruction of wind flows).
4. In cases where the chimney needs repair work (there are cracks, cracks, any protruding elements).
5. In cases where the diameter of the chimney is not chosen large enough, or, on the contrary, is too large.

Pros and cons of using

Any device of this type has both a number of indisputable advantages and a number of disadvantages. This is also true for smoke exhausters.

Among the advantages of such a device, it is worth noting:

• you can not repair the chimney "right now" - the smoke exhauster allows you to postpone repair work for an indefinite period;
• the ability to create the necessary traction by strengthening it, in any weather;
• it is possible to significantly reduce the harm from the formation of condensation due to the fact that the thrust will be increased, and as a result less condensation will be formed;
• the ability to turn off the fan at any time when there is sufficient natural exhaust from the chimney.

List of disadvantages of using such a device:

• it is not always possible to install a smoke exhauster;
• additional consumption of electrical energy (however, in fairness, such fans consume relatively little electricity).

For which chimneys is it suitable?

You can use a smoke exhauster on chimneys for a stove, fireplace, various boilers (gas and solid fuel)

But there is one important condition - such a product can only be mounted on chimneys, in which the temperature does not exceed +600 degrees

Types of fixing chimney hoods

This also applies to heat-resistant models. Although they are designed for high-temperature operation, they are not too high (therefore, they are used for a stove or fireplace, but not for industrial purposes). Moreover, +600 degrees is a very good indicator, many heat-resistant smoke exhausters are even designed for temperatures up to +350 degrees (average).

Purpose and device

Blower fans are installed at the end points of the chimneys and facilitate the removal of combustion products by creating a strong vacuum that draws smoke and other gases out of the furnace and chimney system. The working conditions of the smoke exhauster are characterized by high temperature loads, contact with combustion products contributes to rapid wear and metal fatigue. The design of the smoke exhauster must correspond to the level of loads and ensure efficient operation throughout its entire service life.

The composition of the structure includes:

• heat-resistant fan (made of stainless steel, alloy steel or, less often, carbon steel)
• directing vane installed on the suction side and ensuring the correct direction of flow
• suction funnel connecting the guide vane to the fan inlet
• electric motor

The body of the exhauster, regardless of the material of manufacture, is covered with a protective polymer coating.It increases the service life of parts and helps to reduce thermal corrosion of materials. The direction of inclination of the impeller blades is used both forward and reverse. The first option is most often used on small boilers with relatively mild operating modes, the second option is used on powerful installations with high flue gas temperatures.

For use as smoke exhausters, not only radial, but also axial devices can be used. There are flow-through structures that are located at the outlet of the boiler. They are not completely located in the channel, but only the thrust-increasing part of the impeller. Such designs are not full-fledged smoke exhausters, but as traction amplifiers they are quite effective. The best option is to install a specialized centrifugal type device that gives the maximum effect.

Types of smoke exhausters

If a chimney shaft is built in your house, the draft of which is not enough for the functioning of a new heating unit, then the simplest smoke exhauster for the boiler will help to solve this problem. It is not at all necessary to immediately purchase electromechanical devices; it is enough to install a special deflector at the end of the pipe, which creates additional natural thrust. But when all such options have been tried, you can purchase and install one of the proposed devices:

• fan - natural draft amplifier;
• flow-through smoke exhauster;
• centrifugal traction machine.

A traction amplifier is a device equipped with an axial fan, it is placed at the end of an exhaust shaft or pipe. The performance of the device can be adjusted manually using the thyristor control unit.

Flow-through smoke exhausters for boilers are installed immediately at the outlet of the unit and also serve to increase the thrust force. The design of the apparatus is such that only the impeller is located inside the smoke channel, which does not overlap its cross section. The electric motor and other elements are located outside, which allows the device to be turned on when necessary, and the rest of the time the mine can successfully remove smoke using natural draft. You can control the switching on and performance of the device both in manual mode and in automatic mode by connecting it to the automation of the boiler plant.

In fact, this type of smoke exhausters cannot always serve as a full-fledged traction unit, but only as an exhaust amplifier. The reason is the insufficiently high pressure developed by the impeller of the apparatus due to its design. To get a good result, it is better to put a centrifugal smoke exhauster on a solid fuel boiler. In this case, the control of all functions of the device should be tied to the electronic unit of the heat generator, then the operation of all elements of the system will be coordinated. In addition, centrifugal fans are able not only to create a vacuum in the combustion chamber, but also to develop high pressure, which will force any chimney to work.

In heating units of high power, a forced draft-blowing circuit with two fans is used, this is an ideal option. But the implementation of such a scheme is associated with certain difficulties, since for a balanced operation of the system, it is required to calculate the exhaust fan and blower, the amount of air for combustion and the resistance of the entire gas-air duct, including the exhaust duct.

Homemade constructions

You can make smoke exhausters for boilers with your own hands. This will save money on the purchase of a factory hood. To fold such a car yourself, you only need to purchase an electric motor. The rest of the components can be made from available tools.

Extraction from scrap materials

The set of tools required for work consists of:

• grinders;
• welding machine;
• drills;
• locksmith tools;
• hammer;
• rulers;
• caliper.

Work begins with the manufacture of an exhaust fan. The impeller, sized to the chimney, is attached to the motor shaft. The engine is placed in the pipe with the help of fasteners equipped on its housing.

After connecting the motor to the wiring, during the first test run, it is imperative to check the direction of the air flow and, if necessary, correct the operation of the rotor.

The pipe for placing the turbine is selected with a diameter of 2-3 cm wider. Its length should protrude 3-5 mm beyond the fan. One end of the pipe is welded with a lid, a hole is made in the center of it for the chimney, and one side is equipped with another one, to which the outlet is attached.

During operation, the fan should not cause increased vibration of the hood housing. To prevent this from happening, it is installed using bushings to center the bearings.

The hood assembly is completed by welding the back cover to the tube and attaching the motor to the stand. After connecting the air ducts and electrical wiring to the unit, it is ready for operation.

Intermediate option

This version of the drawing machine assembly does not require special centering of the impeller, which is a rather delicate and difficult job for a layman. A factory-assembled mechanism is usually already centered and only needs to be checked during a trial run.

Sources of

• https://teplo.guru/kotly/tverdotoplivnye/dyimosos.html
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• https://kaminguru.com/dymohod/dymosos-dlja-kotla.html
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• https://otivent.com/dymosos-dlja-tverdotoplivnogo-kotla
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• https://teplofan.ru/sistemy-otopleniya/komplektuyushhie/dymosos

Design and principle of operation

Household smoke exhausters for boilers have the following structural elements:

• impeller housing - made of heat-resistant steel;
• electric motor - powered by alternating current, installed outside the case;
• drive shaft - mounted on bearings with hermetically sealed seals;
• branch pipes - inlet and outlet;
• impeller - made of alloy steel;
• bunker - compartment for collecting ash;
• damper.

What does a smoke exhauster look like for a boiler
When the wheel rotates, the air flow is directed to the center of the exhauster, then it is thrown by the walls of the unit, due to which there is a rarefaction with a gradual inflow of a new portion of air masses.