The coal - fired boilers should be retrofitted to burn biomass fuels

So far, coal-fired boiler pollution emissions are still one of the main sources of air pollution in China. Industrial coal-fired boilers use air pollution control facilities is not extensive. Local environmental protection bureau of the relevant staff generally said that coal-fired boiler supervision difficult. Mainly reflected in the enterprises, the various types of different types of boilers, the end of governance technology is unknown, the policy is difficult to land and so on. In recent years, around the implementation of coal-fired boiler transformation plan, coal instead of coal to gas, biomass fuel in two ways. From the energy security and economic point of view, it is difficult to promote the country to improve gas. In this way, the application of coal to biomass boiler is gradually getting up.

   Coal-fired boilers to change the biomass fuel whether to replace the new boiler, do not change the boiler or not to transform, how to transform, a coal-fired boiler enterprises generally concerned about the problem.

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       There are some customers in order to save money, like coal-fired boilers directly burn biomass fuel, so the procurement of some biomass fuel for trial, the results of biomass fuel combustion is not sufficient, resulting in significant decline in the output of the boiler, and black smoke emissions, and The furnace has a large area of coking situation.

       Coal-fired boilers want to be efficient and stable, to meet the production requirements of the case of burning biomass fuel, you need to understand the burning of coal and biomass fuel characteristics, to take some technical changes to achieve their goals. The difference between biomass and coal is mainly due to its low fixed carbon content, volatile content, the amount of fractions and oxygen content is high, so the biomass fuel burning speed, combustion stroke is short, the focus is not easy to burn.

01

Reconstruction of the blast system

        Reasons for transformation:

       1, the existing blast system using the control of the throttle, the wind size is not good control.

       2, the use of cold air into the wind, because the biomass particles need to burn a lot of oxygen, air volume and wind must be concentrated, coal-fired boiler is the use of cold air blast. So that the process of burning biomass furnace furnace temperature is low, the fire will become smaller and smaller. Boiler temperature is very slow. Resulting in boiler steam pressure and the amount of steam can not meet the requirements. So the existing blast system is only suitable for coal combustion is not suitable for burning biomass particles.

       After the transformation effect:

       1, hot air into the oxygen to increase the amount of combustion effect;

       2, the flow control direction, make full use of boiler heat exchange;

       3, the size of the wind control, is conducive to the combustion of biomass particles and combustion surface, so that the full combustion of biological particles;

       4, the use of hot air into the air to greatly improve the furnace temperature and fire. So that the boiler is warm, boiler steam pressure and steam and larger than the original coal.

02

Increase the secondary aerobic system transformation

        Reasons for transformation:

       Biomass particles burn, the first is a rapid fission, part of the direct combustion of another part of the combustible gas (combustible smoke) need two secondary oxygen combustion, such as oxygen supply is not sufficient combustion will smoke a lot of smoke. Resulting in environmental protection is not up to standard; the original coal-fired boilers did not design the second oxygen so it will cause the smoke pipe mouth will discharge a lot of smoke.

       Transformed into effect:

       1, the biological particles burning, after the second oxygen, so that when the biomass particles burned combustible gas (combustible black smoke) after the second secondary combustion of oxygen, so that the full use of heat to solve the biomass Boiler smoke window often, black smoke is not up to environmental issues.

       2, after the second oxygen control air flow direction, so that the heat and full use of its thermal efficiency significantly improved boiler.

03

Reformation of wind extraction system

        Reasons for transformation:

       Coal-fired boiler wind extraction system is relatively simple, only a single wind. No use of boiler exhaust heat, and the biomass boiler cited winds need large air volume and uniform distribution.

       After the transformation effect:

       1, the wind system can control the size at any time, fully with the blast system and the second oxygen system to enhance the furnace air flow effect, so that the boiler more effective heat absorption and heat exchange.

      2, the use of boiler flue gas heat. So that the boiler to produce hot air and hot air with the wind. The use of biomass particles to burn and increase the furnace humidity. Increase calorific value.

 04

Furnace Renovation

        Reasons for transformation:

       Now the furnace outlet is too large, the exhaust is too Yang Tong, so that a lot of heat with the smoke pipe discharge. Boiler heat exchange time is short. Thermal efficiency is seriously reduced.

       After the transformation effect:

       After the transformation to reduce the furnace out of the air volume, control the temperature of the furnace, slowing the flow of hot air.

05

Feeding system transformation

        Reasons for transformation:

       As the biomass particles than coal burning point is lower, resulting in hopper tempering, so that the hopper particles burning fire, causing a great security risk.

       Benefit after transformation:

       After the hopper and the combustion particles are separated, there is no direct combustion, eliminating the safety of interest.

06

Control system transformation

        Reasons for transformation:

       The existing control system is only suitable for coal boilers and must be redesigned to control systems for biomass boilers.

       After the transformation effect:

       Fully automated control reduces the amount of labor and effectively controls the amount of combustion of biological particles. Greatly reducing operating costs. After the overall transformation of the effect: to improve the furnace (combustion chamber) environment, so that biomass-forming pellet fuel fully burned, from the source of catalytic cracking to eliminate black smoke, oxalic acid and tar.