SU1673787A1 - Vertical furnace with upper gas discharge - Google Patents

Abstract

The invention relates to furnace technology and is intended for the combustion of polydisperse fuels and lignin. The purpose of the invention is to improve the quality of combustion of these fuels. This is achieved by making the vertical furnace body round in cross section and walls extending upwardly at the ledges with different angles of inclination of their individual ring portions. Burners 2 are placed on walls 1 in the middle part of the furnace, tangentially to the conventional circle and tilted down at an angle of 30 - 35 °. In the lower part of the furnace, the nozzle 3 of secondary air is also tangential to its conventional circumference, inclined downward at an angle of 20–25 °, and afterburner grille 4. At the exit from the furnace, a reflective shield 6 is placed coaxially with the furnace; air, and on the perimeter of the shield are located the nozzles 8 of the tertiary air, directed in the same direction as the burner 2. The pipeline 7 is enclosed in the casing 9 of insulating material, forming an annular channel 10 with the walls 1 of the furnace from the firebox. The gases moving upward along the axis of the furnace strike the shield 6 and change direction. When they enter the annular channel 10, tertiary air is introduced into the stream of combustion products, reinforcing the separation effect of changing the direction of gas movement caused by striking them against the shield 6. This air also contributes to the burning of unburned volatile fuel particles. This design of the furnace allows maintaining the temperature of fuel combustion at a level at which the content of nitrogen oxides in combustion products is reduced, and to improve the quality of combustion of polydisperse fuels and lignin. 6 Il.

Description

The invention relates to furnace technology and is intended for the combustion of polydisperse fuels and lignin.

The purpose of the invention is to improve the quality of combustion of polydisperse fuels and lignin.

FIG. 1 schematically shows a firebox, a longitudinal section; in fig. 2 is a section A-A in FIG. 1, in FIG. 3 is a section BB in FIG. one;

n FIG. 4 shows a section B-B in FIG. one; in fig. 5 - section GG in Fig 1; in fig. 6 - section D-Dnafig. one.

The body of the furnace is made round in cross section and with walls extending upwards with ledges with different angles of inclination of individual annular wall sections 1, on which burners 2 are mounted in the middle part of the furnace and directed downward and located tangentially to the conventional circle. Their tilt angle is 30-35 °. In the lower part of the furnace, there are tangential nozzles 3 of secondary air, an afterburning grill 4 and a box 5 for removing focal residues in which a hole (not shown) can be installed to inspect the furnace. The secondary air nozzles 3 are inclined downward at an angle of 20-25 °. In the upper part of the furnace, a reflective shield 6 is placed coaxially with it, to the back side of which a cooling air shield 7 is connected, and along the perimeter of the shield 6 there are nozzles 8 of tertiary air introduced into the fire chamber, directed in the same direction as the burner 2 enclosed in the casing 9 of insulating material, which forms an annular channel 10 with the walls 1 of the firebox to discharge the combustion products from it. At the exit into the channel 10, separation racks 11 made of fireclay bricks are placed. The walls 1 of the firebox have internal lining 12 of fireclay bricks and the outer 13 - of diatomaceous earth, between which there is an air jacket 14, to the lower end of which are connected nozzles 3 of secondary air.

The furnace works as follows. The furnace is kindled using a fuel oil burner or a gas burner (not shown). When the temperature reaches 550-600 ° C, the air mixture is gradually fed into the furnace through the burners 2. At the same time, the supply of fuel oil (or gas) to the pilot burners is reduced accordingly. Sawdust is served at a speed of about 10 m / s. The secondary air through the nozzles 3 is fed at a speed of about 11 m / s, and its amount is 45-47% of the total volume of air entering the furnace. The gases moving upward along the axis of the furnace strike the reflection shield 6 and change their direction of movement, directed toward the periphery of the furnace towards the annular output channel 10. At the same time, tertiary air is introduced through the nozzles 8 through the flow of these gases,

located along the perimeter of the reflective b, which contributes to the intensive mixing of the flue gases and the afterburning of unburned volatile particles

fuel. At the entrance to the annular channel 10, the gases pass through the separation posts 11, as a result of which the largest volatile slag particles (or fuel) are partially trapped. Nonvolatile particles

the fuel is burned on the afterburner grid 4.

The design of the proposed furnace allows for good mixing of the fuel with air and stretching

burning fuel along the length of the furnace, thereby reducing the temperature level of the combustion process and, consequently, the level of nitrogen oxides in the exiting combustion products, which reduces environmental pollution.

Claims (1)

Claims of the invention A vertical combustion chamber with an upper gas outlet, containing burners directed downwards at an angle and installed in the lower parts of the furnace tangential nozzles of secondary air, characterized in that, in order to improve the quality of combustion of polydisperse fuels and lignin, the furnace is made with a circular cross section and with walls extending upwards with ledges at different angles of inclination of their individual ring sections, the burners are located tangentially to a conventionally circumference and their angle of inclination is 30–35 °, secondary air nozzles are inclined downward at an angle of 20-25 °, and at the exit from the furnace a reflective shield is placed coaxially with it, to the back side of which a pipeline for supplying cooling air is supplied along the axis of the furnace, with nozzles of tertiary air along the shield the same side as the burner, the pipeline is enclosed in a casing of insulating material, forming with the walls 5 furnaces are an annular channel for combustion products, and an afterburner grill is additionally installed at the bottom of the furnace. i j ± 13 YU 12 FIG. 2 ten eleven Bb 4 eleven 14 13 FIG. five 15 H / J to