In conditions of fierce competition, furniture companies and sawmills are forced to constantly optimize their costs. One way to minimize them is to use your own wood waste for heating. production premises. For this purpose, enterprises install boiler houses that run on wood waste. Let's look at the operating principle of such a boiler house using the example of the most common boilers of the KTU series today from the Teploresurs company.

General diagram and principle of operation

It should be immediately noted that fuel for heating is loaded mechanically using a screw system or a hydraulic pusher. This gets rid of self made for loading fuel into the boiler. The responsibilities of maintenance personnel include:

1. Control of boiler operation

2. Regularly placing fuel in a special bunker, from which fuel is supplied to the boiler.

3. Cleaning the ash pan. The advanced configuration includes a function for mechanical removal of spent fuel residues, while the basic configuration requires this work to be done manually.

The operation of a boiler can be divided into the following three stages.

1. Drying the fuel. Most waste comes from wood processing plants and therefore has high humidity. To ensure uniform and stable combustion, sawdust is dried on a grate.

2. CO release. An initially low temperature is maintained on the grate, due to which the sawdust releases maximum carbon when burned.

3. Afterburning of CO. The combustion product is supplied to the afterburning zone and burns at a temperature of 900-950 degrees. This allows the carbon oxidation process to occur.

This scheme allows you to significantly increase the combustion efficiency and practically use the full potential wood shavings for space heating. This operating principle is called layered combustion on a grate. Automatic air distribution also contributes to combustion efficiency.

Security systems and automation

In order for the boiler to operate as efficiently as possible in a safe way The following protection devices are used.

1. Thermal insulation of the cladding.

2. Anti-explosion valves. Release excessive steam pressure.

3. Temperature sensors at the coolant inlet and outlet.

4. Temperature sensor waste gases.

All these elements help to effectively take care of the safety of the boiler and prevent possible dangerous situations, and if necessary, give a signal and stop the operation of the unit. The rate of fuel combustion is controlled by dosing oxygen for oxidation. Materials are fed into the firebox using a screw system or a hydraulic pusher.

Advantages of using a sawdust fired boiler

As the main advantages, it is worth noting the low cost of fuel, compared to fossil fuels, and, as a result, low operating costs. The ability to switch from one type of fuel to another (peat, sawdust, shavings, etc.) with minimal changes to the boiler settings is also a significant advantage. Thanks to boilers of this type, you can save a lot. This is especially noticeable if you have to heat large rooms. Purchasing fuel is also not a problem; most logging and wood processing enterprises will readily get rid of several tons of waste that needs to be disposed of.

Waste boilers are a collective unformalized term that combines boilers, furnaces and heat recovery boilers different designs, thermal power, efficiency, purpose and popularity that waste incineration provides of various origins using the heat obtained from combustion instead of expensive and environmentally unsafe burial in special landfills. The most commonly used waste boilers in developed countries include:

• waste incinerators, furnaces and waste boilers manufacturing enterprises and boilers/furnaces/boilers using human waste - usually municipal solid waste;
• furnaces and boilers using waste from the woodworking industry - wood boilers, boilers using wood chips and pellets (specially compressed granules of pre-crushed waste from woodworking enterprises);
• boilers using waste products from the oil refining industry (boilers and air heaters using waste oils - motor, industrial, turbine, hydraulic, transmission) and oils of animal/vegetable origin.

The main characteristics of any waste boiler include:

• efficiency factor, which ranges from 30-40% for waste incineration boilers to 80-90% for pellet boilers (condensing type) and exhaust boilers;
• specific cost of obtaining 1 kW/kJ/kcal of heat when burning a unit volume/mass of waste;

Important: The specific cost of producing 1 kW/kJ/kcal of heat is determined not only by the calorific value of the waste and the efficiency of the waste boiler, but also by:

the cost of additional energy used for burning waste - fuel (gas, fuel oil, waste) used in burners for ignition and stabilization of waste incineration boilers, electricity from compressors/fans that supply primary and secondary air to the combustion chamber, electricity from chamber pushers and electric motors of rotating incineration hearths boilers, electricity, screw mechanisms for loading and cleaning grates of pellet boilers, electricity and fuel for multi-stage waste gas cleaning systems of waste incineration boilers, etc.;

cost of delivery and preparation for waste incineration;

the cost of cleaning the combustion chamber and smoke channels, as well as the cost of measures for the disposal of slags formed after combustion;

initial cost of a waste boiler, size and frequency depreciation charges;

the cost of automation and/or the work of maintenance personnel, etc., etc.

the cost of a furnace/boiler/waste boiler and related equipment/structures/devices/measures that provide a full cycle of waste combustion with slag disposal and purification of burnt gases from impurities up to the maximum permissible concentrations established by international and/or current national legislation.

Waste incineration boilers.

Waste incineration boilers, or less commonly waste boilers, are used in Russia at waste incineration plants, sometimes in large centralized boiler houses. Typical waste incineration boilers are chamber-type, usually with pushers that provide feeding/mixing of waste and cleaning the grate hearth from slag, or are designed as rotary-hearth rotary kilns. To ignite and stabilize combustion in waste boilers, gas and fuel oil burners or waste oil burners are used; more complete combustion is ensured by forced air supply into the combustion chamber (from the loading window, from the bottom and sides), as well as by temperature zoning (in rotary kilns/ waste boilers) ensuring in areas a temperature of at least 1200 degrees Celsius for post-combustion of soot with benzo(a)pyrene and dioxins absorbed in it and a temperature of 1500-1600 degrees Celsius, at which the most complete decomposition/oxidation of dioxins, furans and carcinogens occurs substances.

As a rule, after the waste furnace/boiler, reactors/scrubbers are integrated into the process chain to purify waste gases from solid inclusions, organic and inorganic acids, nitrogen dioxide, sulfur compounds, as well as electric filters for the final purification of burnt gases from fine slag particles and small ash inclusions.

Standards formalized back in the USSR determine the possibility of locating waste incineration boilers no closer than 300 m from residential buildings, and waste furnaces/boilers/boilers must be equipped with an effective system for cleaning burnt gases to the established maximum permissible concentrations for NH3, HF, HCl, NOx, SO2, CO2, CO, dioxins and furans, soot, etc.

The main problems of waste incineration boilers in Russia:

The calorific value of Russian solid household waste is 900-1300 kcal/kg, while waste in the EU countries, USA, Canada due to the higher content of packaging combustible materials and lower content of food waste (no more than 15-20% compared to 35-40 % in Russia) have a calorific value of 2200-2600 kcal/kg. The low calorific value of Russian waste determines the low temperature level in the combustion chamber (at the level of 800-1000 degrees), incomplete combustion of waste, a large amount of slag (30-40% of the volume/weight of the load) and high toxicity of exhaust gases, which necessitates the use of whole complexes for post-purification of gases before their release into the atmosphere and disposal of slags at landfills specially designated for these purposes;

The absence in Russia of preliminary sorting of waste at the places of their collection, as is practiced in the EU, USA and other countries, makes it practically impossible to determine the approximate composition of waste, its calorific value, correction of the combustion process, as well as the presence of ferrous and non-ferrous metals in the slag, which it is advisable to separate from the slag before its disposal;

waste incineration boilers are large-scale units, expensive in terms of initial investment and operating costs, and their installation in enterprises, waste incineration plants or boiler houses requires obtaining a large number of permits from the relevant authorities;

Boilers based on waste from the woodworking industry are currently recognized by the EU as promising heat generators, oriented for use both in local heating systems and boiler heating networks ( thermal power modern boilers using waste from the woodworking industry vary from 2-3 kW to 200 kW or more). If we abstract from typical solid fuel boilers, inefficient, with manual loading of fuel and cleaning of the combustion chamber, which are still sold on the market by a number of manufacturers thermal equipment Russia, it should be recognized that over the past 2-3 decades, boilers using waste from the wood processing industry (firewood, chips, pellets) have gone through the next stage of evolution and today are characterized by ease of use and efficiency in burning wood waste.

Rice. Typical solid fuel boilers.

Boilers using waste from manufacturers in Germany, Finland, and Sweden have an efficiency of 80 to 96% (in condensing-type boilers), equipped with systems for automatic fuel loading, combustion chamber cleaning, monitoring and control of the combustion process and removal of burnt gases (see videos below) .

Video of the operation of an automated wood-burning boiler from Buderus AG, part of the Bosch Thermotechnik division industrial and commercial groups Bosch Group .

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Video of the operation of an automated pellet boiler from Buderus AG.

The main difficulties of arranging heating with wood/pellet boilers in Russia:

heat of combustion of wood coniferous species wood 7.5 - 8 MJ/kg, pellets - 6 MJ/kg, waste oils - 34 - 35 MJ/l, diesel fuel- 33.5 - 34 MJ/l, i.e., to obtain one power of thermal energy, it is necessary to burn 1 liter of waste / diesel fuel, 5.5 kg of pellets or 5 kg of coniferous or hardwood firewood. With the cost of a kilogram of firewood/pellets starting from 6 rubles, the cost of a liter of waste is 6.5 rubles. and a liter of diesel fuel 29 rubles. in the Moscow region, with equal boiler efficiency, this will determine the cost of 1 kWh of energy 3.07 - 3.03 Rub./kWh for diesel fuel boilers, 0.68 - 0.66 Rub./kWh for exhaust boilers, 2.85 - 2.68 Rub. /kWh for wood-burning boilers and 3.39 - 4.05 RUR/kWh for pellet boilers;

The calorific value of wood waste strongly depends on the moisture content of the burned fuel, and therefore, to store a reserve supply of firewood/pellets, it is necessary to equip a special dry room, preferably with control and correction of relative air humidity, and the room should be located in close proximity to the boiler room and have a significant volume sufficient to ensure uninterrupted operation of the waste boiler during operation;

the cost of automated waste boilers - wood and pellets, and even more efficient condensing type ones is very high, and the reliability of the automation is determined both by the quality of the manufactured components and mechanism, and by the quality of the supplied electricity;

typical for Russia, the increase in the number of pellet producers has virtually no effect on their use value, which has been steadily increasing over the past five years.

Boilers using waste - waste oils.

Waste oil boilers are still considered one of the most economical heat generators in terms of initial investment and operating costs, and even in Russia the cost of waste oil remains relatively stable, which is due to the significant costs of waste disposal at supplier enterprises and low demand compared to the current supply on the market. The main advantages of air heaters and boilers for mining include:

• high calorific value of the exhaust, comparable to the calorific value of diesel fuel;
• ease of automation, control and management of boiler equipment and the heating system as a whole, including remotely via the Internet, cellular networks 4G, 3G, EDGE from a PC, Netbook, AppleMacBook, Notebook, smartphone, communicator, iPad, iPhone and iPodTouch (see. );
• the relatively low cost of modern boilers during testing and low operating costs for fuel, maintenance and depreciation of equipment;
• availability of waste oil on the fuel market at the moment and in the future, taking into account the fact that the annual accumulation of used oils in Moscow alone is more than 250 thousand tons by weight and this value is constantly increasing.

The company "BiKoms Holding" is the official distributor of the leading American manufacturer heating equipment on used oil EconoHeat - OMNI USA, an authorized dealer of EnergyLogic (USA) and offers its compatriots - legal and individuals efficient and economical air heaters and exhaust boilers. BiComs Holding specialists will help you choose an air heater or boiler for testing required power, if necessary, design effective system heating systems, will provide full information and advisory assistance during installation and operation, and will perform warranty and post-warranty (under contract) maintenance of boiler equipment.

With rising tariffs for gas and electricity, there is a need to use cheaper types of fuel. These include peat, wood waste, and agricultural waste. Many enterprises are created on sites with no communication of heating networks. There is a problem with the heat necessary for the normal operation of the enterprise. This can be solved by building an autonomous boiler house. To produce heat, waste boilers have been created.

Waste boilers solve two problems important issues. Firstly, they help get rid of unnecessary waste from wood processing enterprises, straw, and cake. Secondly, they help solve the problem with heat for the needs of the enterprise and domestic needs.

Wood waste boiler

Solid fuel boilers are divided into two groups. The first group is boilers that use wood, sawdust, wood chips, firewood up to 1.5 m long, and lump waste as fuel. The second group is boilers with pyrolysis combustion of wood; the package includes a vortex gas generator. Wood gas combustion is used, eliminating the formation of soot. A wood waste boiler allows you to regulate power within the range of 30-100%, while the efficiency remains high. Water serves as the coolant; the package includes a fuel storage tank, which helps ensure round-the-clock uninterrupted operation. Fuel loading is needed once a day. A boiler using wood waste creates the possibility of transferring thermal energy over long distances and can be used for drying in drying chambers. The pyrolysis system allows the use of wood with a moisture content of no more than 20%. The wood waste boiler provides mechanical fuel supply, this guarantees stable combustion of the firebox and allows you to regulate the heat output. Wood waste boiler supports set temperature water at the outlet. The operation of the boiler is controlled using automation. Modifications of these boilers can be represented by the KVSm-OD and KV-Va models.

Wood waste boiler

The waste boiler is completely safe to operate; the kit includes a protection system that meets regulatory requirements fire and technical safety; represents a design that is almost ready for use. A waste boiler solves the fuel problem in an original way, using different kinds wood processing and sawmill waste. They are characterized by reliability, simplicity and ease of maintenance.

Modern trends require industrial wood processing enterprises to maximum efficiency in any process, but the issue is especially acute with waste recycling. Firms that do not have time to adapt to the new format of work risk being left out of the market.

Gave a powerful boost to the industry boiler plants, implemented within the framework of the import substitution program, and having affordable price unlike imported analogues.

Benefits of recycling wood waste

Wood processing waste (sawdust, lump waste slats, wood chips, slabs and wood dust) ultimately constitutes, taking into account deep processing, 60-70% of the volume of input raw materials. That is why recycling of production by-products is so in demand today.

Most industries come out of this situation the old fashioned way, burning waste in layer combustion boilers or “potbelly stoves.” In both cases, the process is accompanied by a large amount of emissions of soot, soot and other environmentally harmful products combustion.

Others “contaminate” their production and surrounding areas, creating a danger for environment, forests and people living nearby, including due to the fact that recyclable materials can spontaneously ignite due to exothermic reactions occurring in their depths.

The situation is even worse with furniture production, where by-products from processing chipboards, MDF and fiberboard must be disposed of in special ovens or “burial grounds”, as they contain toxic phenols and formaldehydes.

Boiler room is ideal for combustion in industrial plants hot water installation gas generator type "Hephaestus".

Features of recycling processes

The process of environmentally friendly waste combustion in boilers includes:

• complete decomposition of phenolic gases harmful to the atmosphere into carbon and hydrogen (flue gases) due to high temperature(>1200 degrees);
• minimum amount of waste in the form of ash.

At the same time, waste and sawdust from sawmills, woodworking, carpentry and carpentry are burned in the boiler. furniture production. This is especially true for the furniture industry.

Principle of operation

The operation of a boiler plant using wood waste is based on the principle of gas generation. In a special unit (gas generator) gasification occurs - thermal decomposition of wood into flue gas and hydrogen.

This disposal method has the following advantages over layered combustion of fuel in conventional boilers:

• high efficiency of boiler plants (up to 90%);
• almost complete smokeless combustion of bulk fuel (ash content does not exceed 1 - 2%);
• the possibility of recycling any by-products of woodworking production, including chipboard, laminated chipboard, MDF;
• installation of spark extinguishing and flue gas purification systems is not required;
• Ease of Management - auto mode dosed fuel supply;
• durability - the boiler's service life without repairs is up to 15 years;
• automatic humidification of dry bulk fuel ( relative humidity 35-55%) prevents heating of the gas generator lining, significantly increasing its service life without repair;
• high maintainability of the gas generator;
• the design of the water boiler eliminates the formation of scale inside the heat exchanger pipes, and also allows the use of equipment for water heating and heating;
• characteristics of emissions into the atmosphere during combustion do not exceed the maximum permissible concentrations(MPC).

Advantages of KAMI

The environmental friendliness of the equipment is confirmed by a certificate based on laboratory tests. The data obtained from the analysis indicate that gas-generating boiler systems can be used even in cities when burning chipboard, laminated chipboard, and MDF waste.

KAMI is an exclusive supplier of boiler equipment. On our website you can choose, compare specifications and buy the installation at favorable prices. Before ordering, consult with the company manager - he will help you fill out your request and help with delivery in Moscow and to any region of Russia, and will also advise you on all types of machines that are in the company’s range, including drying chambers and other types of industrial equipment.

The development of special boilers that use wood waste (for example, wood chips) as fuel was prompted by the need to remove them for disposal. Such processes make wood processing significantly more expensive. The way out of the situation was to burn wood waste and use the released thermal energy for various purposes.

Today, boilers for burning wood waste are most often used in the following areas:

• Residential heating. Usually this is the boiler itself. For private housing conditions this is quite enough.
• Industry. Here, on the basis of the boiler, a special powerful cell is assembled, equipped with additional accessories(electronic control, ash collector, augers for feeding waste into the firebox, smoke exhausters).

According to the principle of wood combustion, boilers using wood waste and wood chips are divided into:

• Fixed grate. Divided into 2 sections. In its straight part, the fuel is burned, and in the inclined part it is dried. The most common method.
• Mechanical grilles. Provides a complex controlled system of alternating fixed and movable grate bars (less often chain grates). Allows the use of lump fuel with a high percentage of humidity, drying and sorting it into fractions in the process of supplying it to the firebox.
• Fluidized bed. The crushed wood is fed onto an inert layer (sand) blown with air. The gradual removal of sand by air flow makes it necessary to constantly add it.
• Flare combustion. The system requires grinding wood to small fractions (chips, sawdust). Vortex firebox type.

Let's look at the differences in the heating principle:

• Air heating

The air intake system is located directly next to the firebox, working on the principle of a convector. The main source of heating is the heat released during the combustion of wood. These models require manual loading of raw materials and low humidity (maximum 20%). Suitable for irregular heating, where heat transfer begins within a couple of minutes after ignition of the fuel.

Air-heating boilers are often used in drying chambers, including for drying wood at wood processing plants and sawmills, where wood waste is always in abundance.

• Hot water boilers

There are 2 types of cameras used here. In one, wood combustion occurs, and in the other, pyrolysis afterburning of heated gases occurs. This significantly increases efficiency, which allows the boiler not only to act as a heater, but also to additionally heat water (located in a special boiler). A chimney system with a large number of elbows also increases heat transfer.

Fuel can be supplied not only manually, but also automatically (continuously). In this case, an additional bunker for wood waste is required. Also, such systems require additional equipment of the boiler with grate blowing (especially if there are several grates). If the boiler has an auto-ignition system based on a plasma arc, then special sensors are required to monitor whether a fire has occurred. If there is no flame or heating, then they give a signal to fire the arc again. Water heating boilers using wood waste, equipped with electronic automation panels, sensors and a continuous supply of fuel, require additional power from the electrical network (consumption up to 300 W per hour). Allows you to work with damper fuel with humidity up to 40%.

Manufacturers and prices

Most imported boilers from companies such as Hargassner, Viessmann, Heiztechnik have a fairly high price. This is due to the use large quantity electronics and complex furnace systems. The quality is certainly excellent, but is it worth paying extra for additional functions depends on whether you need them.