RU2824507C1 - Coal gasification device - Google Patents

Abstract

FIELD: heat power engineering.

SUBSTANCE: continuous-action layered gasifier containing a shaft-type apparatus on reverse blowing and consisting of furnace 1 with a horizontal cooled grate 2, formed from pipes 3 with cooled liquid, installed in lower part of shaft, under them in the side wall there is a gas removal unit 6, on the lower surface of the shaft a slag and ash afterburning zone is formed, with possibility of removal of gasified gas released on it during afterburning of fuel in particles of slag and ash 10, feeder of continuous supply of fuel to furnace, at the same time at the top of the apparatus there is an air supply unit from top to bottom 7. On cooled pipes 3 of grate 2 there are studs 4, which are moved by hydraulic cylinder 5 in different directions towards each other, and air supply unit 8 is additionally equipped with nozzles 9 located in high-temperature zone along the perimeter.

EFFECT: improved quality of gasification of various types of coals, including sintered coals.

1 cl, 3 dwg

Description

The technical solution relates to the field of thermal power engineering, namely to devices for burning coal using the gasification method to obtain gaseous fuel.

1. There are known methods of gasification of solid fuel in shaft-type devices, which provide for sequential loading of fuel, gasification of fuel, removal of gasification products, using the example of work at the enterprises of OJSC Norilsk Nickel, CJSC Carbonika-F. The disadvantage of this method is the continuous operation of two or more devices operating sequentially, which complicates the technological process, requires high metal consumption and large areas.

2. A method of continuous coal gasification using the "Termokoks-KS" technology is known, used by JSC SUEK. This method provides for continuous coal gasification and continuous removal of solid gasification products (ash, coke). The disadvantage of this method is that it does not completely gasify the incoming solid fuel, and the generator gas burns directly above the surface of the gasified fuel and cannot be transported and used for further processing, and coke residue is formed during the gasification process.

3. A method of reverse gasification process or gasification process with downward air blast is known. From the description of the invention "Layer Gasifier" (RU Patent No. 2513928, IPC C10J 3/20 (2006.01), F23B 40/02 (2006.01), published on 20.04.2014) It includes the continuous supply of solid fuel into the shaft onto its grate, forming on it from top to bottom a layer of solid fuel distributed over the volume in the form of a truncated pyramid, its ignition of the solid fuel on the grate and the subsequent supply of air under pressure exceeding atmospheric, the formation of a high-temperature gasification zone above the grate with the excitation of the process of a reverse thermal wave moving towards the air flow of the resulting generator gas as a result of the process of heating the solid fuel in the said zone, and the removal of the said gas from the shaft through its lower part located under the grate. In this case, the grate formed from cooled pipes with toothed wheels freely rotating on them is first given an angle of inclination to the horizon, ensuring the self-convergence under the action of gravity of the slag of solid fuel and ash to the bottom of the shaft below the outlet of the generator gas. As solid gasification products and ash accumulate in the lower part of the gas generator, they are removed mechanically outside the shaft.

The disadvantage of this solution is the low efficiency of the gasification process, since the incoming solid fuel is not completely gasified. This is due to the uneven distribution of solid fuel in the mine, which leads to low controllability of the gasification process, caused by the presence of inert slag and ash coming off the grate and the occurrence of blockages at its outlet, leading to the occurrence of a violation of the solid fuel gasification mode. As a result, a lot of unburned coal is formed in the slag and ash.

The prototype of the claimed technical solution is the "Method for gasifying solid fuel and the device implementing it according to the patent for invention of the Russian Federation: RU 2607397 C2 dated 10.01.2017, IPC F23B 40/02, C10J3 /06, which includes continuous supply of solid fuel into the shaft onto its grate with the formation of a distribution of solid fuel on it from top to bottom, wherein the continuous supply of solid fuel into the shaft onto its grate is carried out uniformly distributing the solid fuel in the volume of the shaft, starting from the grate and up to the place of its loading. At the bottom of the shaft, in the zone of the discharge of generator gas from it, a zone of afterburning of slag and ash that have passed the grate is formed. The generator gas is removed in the general flow of generator gas removal from the shaft, while an active layer of slag and ash is formed on the grate, the activity of which and its level control the position of the high-temperature zone in the solid fuel in the shaft and the speed of passage of slag and ash down the shaft to the zone of their afterburning. The grate is preliminarily placed horizontally in the shaft, and its toothed wheels are forced to rotate in one direction or in different directions, activating the adjacent layer of slag and ash.

This gasification device is selected as a prototype, since it is aimed at solving the same problem as the claimed invention, and contains the greatest number of essential features that coincide with the essential features of the claimed invention.

However, the prototype has a number of significant drawbacks: When burning coal with certain characteristics of ash residues, large sintered compounds may form, which does not allow the design of the gear wheels to effectively remove them to the afterburning zone, which reduces the combustion efficiency by making it difficult for the oxidizer to pass through the fuel layer into the active gasification zone.

The disadvantages of these analogues and the prototype pose the problem:

- improvement of the grate design for high-quality removal of ash residues;

- maintaining stable combustion and the required temperature regime when burning sintered coals of various fractions and calorific values in static and dynamic modes;

- improving the burnout of carbon particles in combustion products (slag). The set task is achieved by the fact that in a continuous-action layer gasifier, containing a shaft-type apparatus with reverse blast and consisting of a furnace with a horizontal cooled grate formed from pipes with cooled liquid installed in the lower part of the shaft, a gas removal unit is installed under them in the side wall, a slag and ash afterburning zone is formed on the lower surface of the shaft, with the possibility of removing the gasified gas released there during the afterburning of fuel in slag and ash particles, while at the top of the apparatus there is an air supply unit from top to bottom. Spikes are installed on the cooled grate pipes, the movement of which is carried out in a horizontal direction in different directions towards each other, the air supply unit is additionally equipped with nozzles located in the high-temperature zone along the perimeter.

The technical result of the claimed invention is to improve the quality of gasification of various types of coal, including sintered coal.

The limiting features of the invention "a continuous-action layer gasifier containing a shaft-type apparatus with reverse blast and consisting of a furnace with a horizontal cooled grate formed from pipes with cooled liquid installed in the lower part of the shaft, under them in the side wall a gas removal unit is installed, on the lower surface of the shaft a slag and ash afterburning zone is formed, with the possibility of removing the gasified gas released therein during the afterburning of fuel in slag and ash particles, a feeder for continuously feeding fuel into the furnace, while at the top of the apparatus there is a unit for feeding air from top to bottom" describe the common elements of prototypes and analogs of gasification devices, as well as the claimed technical solution.

The distinctive features of the invention "on the cooled pipes of the grate, spikes are installed, the movement of which is carried out in a horizontal direction in different directions towards each other, the air supply unit is additionally equipped with nozzles located in the high-temperature zone along the perimeter" will allow achieving the declared technical result, namely, improving the quality of gasification of various types of coal, including sintered coal.

The proposed design of the coal gasification device is illustrated by a figure on the graphic sheet. Fig. 1 shows a section of the gas generator - side view, Fig. 2 - a section of the gas generator - top view, Fig. 3 - a section of the grate - side view.

The claimed technical solution consists of a furnace 1 with a movable horizontal grate 2 made of cooled pipes 3 with spikes 4, a hydraulic drive 5, a feeder for continuous fuel supply (not shown in the drawing) to the furnace 1, a gas removal unit 6 located under the lower part of the furnace 1, an air supply unit 7 in the upper part of the furnace, an air supply unit 8 in the high-temperature zone of the furnace with nozzles 9, a slag and ash afterburning zone 10, and pipe collectors with cooled liquid 11.

The device constructed as a shaft-type apparatus according to the proposed scheme operates as follows. Solid fuel (coal) is fed into the shaft-type apparatus for gasification from above. Fuel is fed continuously onto the grate 2 of the shaft with the formation of a layer distributed uniformly from bottom to top throughout the volume of the shaft. The volume from the bottom of the grate to the inlet of fresh fuel into the shaft is maintained continuously during the gasification process. Ignition of the solid fuel on the grate 2 formed from cooled pipes 3 with spikes 4 is carried out with firewood. From the moment a layer of coal from burnt firewood is formed on it, the initial fuel is fed into the shaft. After ignition, air is fed from top to bottom under pressure exceeding atmospheric pressure with the ignition of the fuel adjacent to the grate 2 located in the high-temperature zone (HT) of gasification, and the excitation of the process of the reverse thermal wave (gasified gas), moving towards the air flow as a result of the process of overheating of the solid fuel. Then the gas, passing through the grate 2, enters the afterburning zone 10 and exits through the gas removal unit 6, located in the lower part of the device, under the grate, where a constant vacuum created by the smoke exhauster (not shown) is maintained. Moreover, the continuous supply of solid fuel into the shaft to the grate 2 is carried out, uniformly distributing the solid fuel in the volume of the shaft 1, starting from the grate 2 and upwards to the place of its loading (zone Bx). The generator gas obtained in the afterburning zone (Do) is removed in the general flow of generator gases through the gas removal unit 6, located under the lower part of the furnace 1. In this case, an active (Act) layer of slag and ash is maintained on the grate 2, the activity of which and its level are controlled by the position of the high-temperature zone (HT) of the solid fuel in the shaft and the speed of passage of slag and ash through the grate 2 down the shaft into the zone of their afterburning. Moreover, the grate 2 is preliminarily placed in the shaft 1 horizontally, and its studded pipes 3 are given forced multidirectional, horizontal movement, using the hydraulic cylinder 5, activating the adjacent layer of slag and ash. It should be noted that when air is supplied from top to bottom under pressure exceeding atmospheric, this is done with the ignition of another high-temperature zone (HTZ) of gasification in the solid fuel, formed above the high-temperature zone (HTZ) adjacent to the grate 3, and the excitation of the process of a reverse thermal wave in it, moving towards the air flow and the pyrolysis gas formed as a result of the process of overheating the solid fuel.

The intensity of air supply through nozzles 9 in the high-temperature zone is regulated depending on the type of initial fuel (coal grade, its type, condition), which affects the activity of the slag and ash layer on the grate 2 and determines the translational movement of water-cooled pipes 3 with studs 4 of the grate, which makes it possible to regulate the removal of slag and ash through the grate.

In this case, the movement of the liquid for cooling the grate 2 is carried out through pipes 3 through the collectors of the distribution of the cooling liquid 11, located on both sides of the grate. Thus, with the help of the translational movement of the declared studded cooled grate and the correct distribution of the incoming air into the gasifier furnace, solid fuel (coal) is effectively processed into energy gas, which is then supplied to the consumer, for example, to the boiler furnace.

The above set of restrictive and distinctive features of the claimed device for coal gasification, namely the distinctive features of the invention formula (in aggregate its restrictive features) is not known at this level of technical development and does not follow from the generally known rules for the design of such devices, as well as the methods (techniques and technologies) for their operation, which proves compliance with the criterion of “inventive step”.

The declared device in terms of design is not identified from the existing level of technological development, which allows us to conclude that it meets the criterion of “novelty”.

The constructive implementation of the declared technical solutions with the specified set of features does not present any design, technical or technological difficulties, which implies compliance with the criterion of “industrial application”.

Claims (1)

A continuous-action layer gasifier comprising a shaft-type apparatus with reverse blast and consisting of a furnace with a horizontal cooled grate formed from pipes with cooled liquid installed in the lower part of the shaft, a gas removal unit is installed in the side wall under them, a slag and ash afterburning zone is formed on the lower surface of the shaft, with the possibility of removing the gasified gas released therein during the afterburning of fuel in slag and ash particles, a feeder for continuously feeding fuel into the furnace, while at the top of the apparatus there is a unit for feeding air from top to bottom, characterized in that spikes are installed on the cooled pipes of the grate, the movement of which is performed in a horizontal direction in different directions towards each other, the air supply unit is additionally equipped with nozzles located in the high-temperature zone along the perimeter.