Currently, pyrolysis boilers have receivedquite widespread. This is due to the fact that as a result of a two-stage combustion of solid fuel, its complete combustion takes place. This greatly increases the efficiency by almost 90-92%. What kind of boilers are these? What does the pyrolysis boiler connection diagram look like? The answers to these questions can be found in this article.

Pyrolysis boiler - what is this?

Pyrolysis boiler is a varietysolid fuel boilers. As a rule, these are water-heating boilers. In this device, the combustion of solid fuel and volatiles released by it is carried out separately.

Types of fuel

As fuel for pyrolysis boilers, you can use:

• Peat, fuel briquettes.
• Waste of furniture production.
• Wastes from timber processing, sawdust.
• Various firewood: spruce, lime, pine, birch, alder, oak, etc.
• And many other types of solid fuel.

Operating principle

Before considering the schemes and drawings of pyrolysisboilers, you need to understand the principle of their action. So, in the process of fuel combustion (differently referred to as dry distillation) under the influence of a high temperature regime (about 200-800 ° C) and insufficient oxygen, the wood is decomposed into two parts: a volatile part (pyrolysis gas) and a solid precipitate charcoal).

The pyrolysis boiler circuit assumes that at the topthe chamber will accumulate pyrolysis gas, which, with the air flow created by the smoke exhauster, will be sent for afterburning to another chamber. This is an exoteric process, accompanied by the release of heat, which improves the heating, the boiler dries fuel, and also provides heating of the air entering the combustion zone. The mixing of pyrolysis gas liberated at high temperature with oxygen of air causes the combustion process of the first, which is subsequently used to generate thermal energy.

Efficiency

How effective will the pyrolysis boiler circuit, as well as the time of its operation, depend on many factors:

• Type of fuel and humidity.
• Thermal insulation of the building.
• The temperature in the room.
• Air temperature in the street.
• Accuracy of design work in relation to the heating system.

Naturally, unlike conventional boilers,gas-generating equipment is much more efficient. Since when burning wood, it is impossible to obtain such high temperature values ​​as in the combustion of wood gas obtained from it. The use of a smaller volume of air is envisaged during the combustion of gas. In this connection, the burning time and temperature increase. It should also be noted that the management of the pyrolysis gas combustion process is much easier.

Advantages

So, the pyrolysis boiler scheme has the following advantages:

1. Full combustion of fuel. Thus, the combustion process is economical, as a result, it is necessary to clean the flues and the ash box less often.
2. With the help of the primary air supplyregulation of the combustion process. This allows for a long time to work on one tab - about 12 hours (3-4 hours - in conventional boilers). There are devices in which you can bookmark up to 6-7 days on coal and on wood - from 30 hours.
3. The scheme of the pyrolysis boiler with automatic adjustment of parameters. The process of burning pyrolysis gases is perfectly adjustable and controlled.
4. Two-stage combustion increases efficiency.
5. It is possible to burn large firewood.
6. The absence of fusible layers facilitates cleaning.
7. Due to the combustion of pyrolysis volatile gases, emissions of harmful substances into the atmosphere are reduced.
8. When disconnecting electricity, this device is able to operate at minimum power.
9. In contrast to the conventional direct combustion method, the duration of fuel combustion in these boilers is about 3-5 times longer.
10. When loading the boiler at 50-100% efficiency will be about 85-92%. Thus, the scheme of the pyrolysis boiler operation will be more economical by about 4-7%.

disadvantages

1. Volatility - does not work well in the absence of a supercharger or exhauster.
2. Higher cost - about 1.5-2 times.
3. At low loads (less than 50%), unstable burning is observed, tar formation is possible in ducts.
4. Such devices are demanding on the moisture content of the fuel.
5. The wood scheme of the pyrolysis heating boiler excludes the organization of automatic fuel supply.
6. To prevent low temperature corrosion,as well as condensation in the gas path, it is necessary to ensure that the return water temperature is at least 60 ° C (in rare cases 40 ° C). However, this problem is solved by adding direct water to the return.
7. Compared to gas and electric devices, the overall dimensions of these boilers are much larger. This aspect must be considered when choosing an installation site.

Fuel used

The fuel must be usedwood with a diameter of 100-250 mm and a length of 380-450 mm. Fuel briquettes should be 30 × 300 mm. In the process of burning wood it is allowed to use small sawdust. However, they should be added not more than 30% of the total volume of the loading chamber. Only in this case, the scheme of the homemade pyrolysis boiler will be effective. In addition, these devices are capable of burning wet firewood, but provided that their moisture percentage is no more than 40.

To ensure the functioning of such a boilermaximum power, you must use only dry fuel. Since the ability to release fuel energy is determined by taking into account the presence of water in the wood.

Pyrolysis boiler assembly scheme

Before assembling this heating systemwith your own hands, you need to familiarize yourself with the scheme. If you do not have any knowledge in this area, do not try to do everything from scratch on your own. It is enough to take the finished drawing and make small adjustments to suit your own requirements. Get a scheme specifically for your equipment. In the special literature can find schematic diagrams and drawings of pyrolysis boilers.

Essential elements

For example, take the finished Belyaev boiler circuit with a power of 40 kW. It contains the following main elements:

1. The contour controller for the boiler.
2. A door designed to load fuel.
3. Ashtray cover.
4. Smoke exhauster
5. Clutch for temperature sensor fuse.
6. Connection pipe for emergency line.
7. Feed line.
8. Supply in the protective heat exchanger of cold water.
9. Supply to the protective heat exchanger of hot water.
10. Backbone.
11. Emptying pipe and expansion tank.

Certainly having experience and some engineeringknowledge, you can easily change the design of the boiler. Connection diagram of the pyrolysis boiler can be modified at your discretion. However, the work must be done in such a way as not to disturb the dimensions of the inner chamber.

Tools and materials

To mount such a unit on its own, you need the following set of tools and materials:

• Thermal sensor.
• Fan.
• The strips have become of different thickness and width.
• Set of pipe with a diameter of 2 mm.
• Metal sheets 4mm thick.
• A set of pipes of various diameters.
• Cutting wheel diameter of 230 mm.
• Grinding wheel with a diameter of 125 mm.
• Manual circular saw (Bulgarian).
• Several packs of electrodes.
• Welding machine.
• Electric drill.

If you are planning to make yourselfpyrolysis boiler, the recommended thickness of steel should be 4 mm. To save money, you can use steel with a thickness of 3 mm. For the manufacture of the device will require durable steel that is able to withstand high temperature conditions.

Pyrolysis boiler - manufacturing scheme, the main stages

In order to independently assemble a gas generator heating unit, the following requirements should be followed:

• Necessary elements should be cut by the grinder.
• The hole for loading fuel is placed slightly higher than that of solid fuel devices.
• To control the incomingthe combustion chamber of the amount of air, you must install a limiter. It can be made with a pipe with a diameter of 70 mm, and the length should be slightly larger than the body of the boiler.
• Using a welding machine, a steel disc is welded, which, together with the pipe walls, should form a gap of approximately 40 mm.
• Чтобы установить в крышке котла ограничитель, need to do the appropriate hole. It should have a rectangular shape. The hole is closed by a door equipped with a plate of steel. This will ensure a secure fit. Below is a hole designed to remove water.
• Using a pipe bender, it is necessary to bend a pipe designed to move inside the boiler coolant. This ensures maximum heat transfer.
• Regulation of the amount of coolant sent to the device can be carried out by means of a valve mounted outside.
• As soon as the first launch is completedequipment in the combustion products should not be carbon monoxide. If this condition is met, the tying of the pyrolysis boiler (the scheme is indicated) is done correctly. It is important to regularly monitor the state of the welds of the device and timely remove the soot and ash from it.

A great option can be a jointthe use of the pyrolysis boiler is not with a classic water heating, but with air heating systems. As a result, the air will be transferred through pipelines, and its return to the system - by floor. Such a system has many advantages: in severe frosts it does not freeze, during the departure of the owner there is no need to drain the coolant.

Mounting Tips

• The installation of the pyrolysis unit shouldbe made with the strictest observance of fire safety requirements. This device involves the processes of combustion, which are characterized by high temperature indices.
• The boiler room should be in a separate non-residential premises.
• To maintain proper ventilation of air, a 100 cm hole must be provided.².
• Installation of the unit is made on a brick or concrete base.
• For the fire chamber before the cameras must be installed protection. It is a metal sheet 2 mm thick.

On this self-installation of the pyrolysis boileris over. As you have already noticed, there is nothing complicated about it. The main thing is that the detailed scheme of the pyrolysis boiler was correctly made. If you are not confident in your own abilities, then you shouldn’t be tempted - contact the professionals.

User's manual

Air supply can be done in two main ways.in the ways: method of forcing or the exhaust way (use of the smoke exhauster). The use of the injection variant allows you to adjust the power of the flow, which allows you to control the intensity of combustion, the transition from smoldering to the issuance of maximum power in a short period of time.

As for the smoke exhausters, today they produce such structures that can provide vacuum traction, capable of carrying out the pyrolysis process without heat loss.

The most economical mode of operation of the boiler is when water is heated to 60 ° C. If you comply with all the conditions, then this temperature is reached after 30-40 minutes.

Normal functioning of the heating systemdirectly depends on the moisture of the wood. It is not recommended to use firewood with humidity above 50%. The most optimal is the moisture content of wood, equal to 25-30%. In order to achieve this percentage of moisture, it is necessary to dry firewood for a long period in ventilated areas, in special woodsheds, sheds (depending on the initial humidity and wood type).

When using wood with a moisture content of 15-20%, compared with 50% humidity, power increases by about 2 times. However, in natural conditions, it is rather difficult to obtain such moisture. It will take approximately 1.5-2 years. Therefore, immediately after the end of the heating season, it is necessary to proceed to the procurement of firewood.