The problems of the usage of the coal of low quality or different sorts are well known.
Even through a standard technology of burning of sort coals the underburning comprises 10–50% or the process of burning takes place in places where it does not influence the degree of efficiency, for example in gas flues. The underburning of the fuel particles takes place in zones which are low in oxidant, that is why ideal conditions for the full burning are with keeping the stoichiometric ratio of the oxidant and the fuel in every point of the stream.
To exclude the underburning and consequently to increase the effectiveness in the suggested technology there are used: the preparation of coal-water slurry, activation of the oxidant, the homogenizing of the blended fuel through its dispersion, the burning of the fuel in the vortical stream in a precombustion and the afterburning in a boiler furnace.
Our system of machines and technologies for the preparation of coal-water slurry (CWS), its homogenizing, the spraying by dispersing sprayers and its burning in fire-chambers by vortical precombustion burners aloow to create multi-purpose and efficient plants for heating boiler installation of different heat productivity. The technology allows to convert any solid-fuel boiler installations to CWS burning and to use the coal with practically any initial characteristics: composition, brand mark, size of initial particles (fragments). That all is possible due to the fact that CWS consisits of 3 main components: coal with particles of 250-300 micromicron in size (60-65%), water (35-40%), the stability improver (up to 1%).
CWS surpusses initial coals in burning conditions and the level of burning-out: the ratio of the burning-out increases up to 99,5%, the burning of the coal in the form of CWS allows to practically prevent the volatile ashes formation, to reduce the ejection of nitric oxide into the atmosphere in 6-8 times and to reduce the content of the sulfur oxide in 50-70%. Taking into consideration the fact that CWS is a explosion- and fire-proof fuel and the system of acceptance, storage and supply for the burning is similar to the system used for the liquid fuel, the appropriateness of converting of solid- and liquid-fuel burning installation to CWS is obvious. Here the difference of the cost of solid and liquid fuel should be kept in mind.
Thus it is obvious that the CWS has several energy and ecology advantages and the production of coal-water slurry change traditional concept of the coal by new opportunities for its usage.
The basis of the high efficiency of the suggested tehnology for the complex usage of the solid fuel is our system of new hardware:
- the system of efficient crushing-grinding equipment for the preparation of CWS of the necessary quality;
- vortical energy-converters-homogenizer for the blending of fuel and oxidant before spraying - ozonizers and the technology for the oxidant activation - water and air;
- vortical dispersing sprayer for the steady process of spraying of the blended fuel with alternate viscosity;
- vortical precombustion burner for the kindling, highlight and burning of CWS;
technological system for the deep processing of ashes and cinders.
We suggest the development and delivery of new equipment and technologies for the production, preparation, spraying and burning of CWS with the fullness of burning in power-generating boilers of different purposes and productivity, and the equipment for the deep processing of ashes and cinders. This equipment aloows to:
- use initial coals of different sorts, quality and characteristics for the burning in the fire-chamber;
- improve ecological characteristics of the production and ejection;
- save up to 150 rubles in every tonn of the burned coal.