RU1789828C - Solid propellant combustion plant - Google Patents

Abstract

Usage: in the power system for burning solid fuel in the molten slag. SUMMARY OF THE INVENTION: the apparatus comprises a chamber 1 with a window 2 for exhausting slag, blasting tuyeres 9, a gas exhaust duct 3, an air supply device 6, and a fuel supply device. The latter includes a hopper 4 and a feeder connected to it in the form of a vertical cyclone 5 adjacent to the wall of the chamber 1 and connected to it in the middle by a channel 6 for passing liquid slag, and in the lower part by an ejector, In cyclone 5, solid fuel is mixed with liquid slag; and the prepared combustible mixture is ejected into the chamber 1 below the melt level. 2 ill.

Description

The invention relates to a power system and can be used to burn fuel in a molten slag to produce heat used to generate steam.

A number of technologies are currently being developed for the efficient combustion of low fuel oil fuels in thermal power plants. One of them is the technology of burning fuel in a melt of slag sparged with oxygen-containing gas. As a basis for the process, sulfide ore processing technologies in pyrometallurgical units were used. In various designs of these units, a common feature is the design of a loading device for feeding the charge and fuel in the form of an opening in the arch or wall of the furnace in communication with the estrus and hopper. Fuel and charge are fed from above to the melt most often in the direction of the flow of exhaust gases. Therefore, all units of this design are characterized by more or less significant dust extraction. Reducing this indicator is an urgent problem, especially when using the heat of exhaust gases in waste heat boilers.

A well-known energy-technological unit (ed. St., No. 832250) containing a melting chamber with a radiation shaft installed above it and a loading device made in the form of a ceiling hopper placed in a radiation shaft with an opening for supplying the charge. The mixture is distributed over the mine section towards the flow of gases from the melting chamber passing through the scallop for further cooling.

 When using the known device for burning fuel in the slag melt, its operation is accompanied by significant dust removal, since with increasing distance from the loading point to the surface of the molten bath, the dust removal increases (Grechko A.V., Ivanov V.V., Knev M.V. Reduced dust removal when loading the mixture into bubbler pyrometallurgical units. - Non-ferrous metals, 1987, No. 7, pp. 39-41).

A known installation for melting and burning material, including solid fuel (autosw. No. 438855), comprising a chamber with a slag discharge window, blast tuyeres, a gas exhaust duct, and a fuel supply device. The latter includes a hopper connected to the feeder and feed pipe. The pipe is buried in the chamber. A blowing device and a gas pipeline are connected to it. The loaded bulk material, together with dust and fines, enters

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a loading pipe where the dust burns and melts; in bulk material and drops of the melt fall on the surface of the melt. Due to this, dust is reduced by upward gas flows,.

A disadvantage of the known solution is the ablation of ash from the combustion of dust and partially unburned residues, which complicates the operation of waste heat boilers, the gas path, and the dust collection system.

The supply of gas and combustion air to the feed pipe requires additional energy costs, which reduces the economics of the installation. In addition, when lump fuel arrives at the top of the melt, its preparation for burning starts only when it contacts the melt, which slows down the combustion process and reduces its efficiency.

 The aim of the invention is to reduce dust removal and increase the efficiency of burning solid fuel in the slag melt.

This goal is achieved by the fact that in the installation for burning solid fuel containing a chamber with a window for exhausting slag, blasting tuyeres, a gas outlet, devices for supplying fuel and air, the feeder is made in the form of a vertical cyclone with a tangential channel in the middle of the body and axial a hole in the bottom, communicating the cyclone, respectively, with the chamber and with the device for supplying air, which is made in the form of an ejector and placed under the bottom of the cyclone, while the upper edge of the tangential channel is not higher bottom edge of the slag outlet window.

The design of the feeder in the form of a vertical cyclone, connected in the middle part with the chamber volume by a tangential channel, makes it possible to organize the mixing of liquid slag with solid fuel in a cyclone and prepare a well-heated combustible mixture. The location of the upper edge of the channel at a level not exceeding the level of the lower edge of the window for the discharge of slag, eliminates the communication of the gas volume with the feeder and the removal of dust by exhaust gases.

The connection of the feeder with the volume of the chamber by means of an ejector makes it possible to create a driving pressure for supplying liquid slag to the cyclone and a mixture of fuel and slag from the cyclone into the chamber.

Submission to the melt level of the mixture prepared for combustion increases the efficiency of the entire combustion process and eliminates the entrainment of dust and burnt

particles of fuel. The absence of the need for air and gas to burn the dust in order to eliminate its entrainment increases the efficiency of the installation.

In FIG. 1 shows a proposed installation; in FIG. 2 is a section AA in FIG. 1.

The installation comprises a chamber 1 with a window 2 for exhausting slag, a gas exhaust duct 3 and a device for supplying fuel. The latter includes a hopper A and a feeder in the form of a cyclone 5, communicated by channel 6 with the chamber 1. In the lower part, the cyclone 5 is connected through an opening 7 to the device for supplying air 8, made in the form of an ejector for feeding the mixture into the chamber. The lances 9 are located in the chamber 1. The lumen 1 may have several fuel supply devices depending on the capacity of the installation.

Installation works as follows,

Solid fuel, together with dust, enters from the hopper 4 into cyclone 5. Liquid slag enters here through channel 6. located below the liquid level in the chamber. The ratio of fuel to slag consumption should be such that the liquid state of the mixture is maintained. This ratio is governed by the fuel consumption from the hopper and (or) the performance of the ejector.-Top-

Either mixed with liquid slag, it undergoes intense heating, cracking with the release of volatile components. The combustible mixture thus prepared enters chamber 1. The combustion of the mixture begins at the outlet of the ejector.

In this state, the mixture enters below the melt level into chamber 1, where the combustion continues in the melt volume under the influence of an oxidizing agent coming from tuyeres 9 and sparging the melt. The resulting gases are sent to the exhaust pipe 3, and the slag is drained through a window 2 located in the siphon of the chamber 1,

Due to the fact that cyclone 5 is not in communication with the gas volume of chamber 1 (since channel b is always below the melt level), dust removal with exhaust gases is eliminated. The entry of a well-prepared combustible mixture to the melt level significantly increases the efficiency of the fuel combustion process in the slag melt, and also contributes to the absence of entrainment of solid combustion products into the exhaust duct.

A step-by-step process of fuel combustion is practically carried out in the installation, which contributes to the reduction of MOx in the exhaust gases and to the improvement of environmental performance of the process.

Claims (1)

SUMMARY OF THE INVENTION An apparatus for burning solid fuel in a melt of slag comprising a chamber with a window for discharging slag, blowing tuyeres, a gas exhaust duct, a device for supplying fuel and air, characterized in that, in order to reduce dust emission and increase the efficiency of fuel combustion , the feeder is made in the form of a vertical cyclone with a tangential channel in the middle part of the housing and an axial hole in the bottom, communicating the cyclone with the camera and with the device for supplying air, which is made in the form of an ejector and zmescheno under the bottom of the cyclone, while the upper edge of the tangential channel is not higher than the lower edge of the window for slag discharging. FIG. 2