SU663735A1 - Heat-treating furnace - Google Patents

Description

(54) THERMAL OVEN

one

The invention relates to the field of meta-thermal heating equipment of furnaces for heating and heat treating a metal and can be used at the plants of the metallurgical and machine-building industry.

A heat treatment furnace is known that contains a lined working chamber with low pressure burners and a smoke removal system, for example, a recirculating flame furnace ij. A disadvantage of the known construction is the low intensity of heat exchange in the furnace.

It is known that oscillations of a certain frequency and power in the gas atmosphere of the furnace can intensify KOHI JCTUB heat exchange, affecting the boundary layer near the surface of the heated metal. Such oscillations Mbrjrr Excite various kinds of acoustic burners or devices characterized by the pulsating nature of the combustion.

The disadvantage of these pulsation burners significantly depends on the flow of gas and air. In addition, the known constructions of pulsation burners cannot be used for heating furnaces, since they cannot burn gas at the expense required to ensure the required level of temperatures in the working chamber and the unsatisfactory quality of fuel combustion.

The purpose of the invention is the% 1% uniform heating of the metal and the intensification of heat transfer in the working chamber.

This is achieved by the fact that the furnace is equipped with acoustic oscillation devices installed at the outlet of the low-pressure burners. The goal is to stabilize the length of the waveguide and control the pulsation frequency. A device of acoustic oscillations Made in a tube with pipes for supplying gas and air and a washer that can move along its axis, with the walls of the pipe being water-cooled.

The drawing shows the furnace, the cut. The thermal oven contains a lined working chamber 1, closed below 2, on which delivery 3 is installed for a heated load 4.

Burners 5 ® 1ШШ 1ШПШМ; 15е1а of the Outdoor are installed in the furnace walls with a rifle tunnel 6, guiding tunnels 7, an acoustic oscillation device (pulsators), made in the form of a water-cooled pipe -8 with pipes 9 and 10 respectively supplying gas and air, nozzle inserts 11c with water inlet nozzle 12 and outlet 13, check valves 14 and washer 15 having the possibility of movement along the pipe axis.

The furnace works as follows. The main amount of gas supplied by the low-pressure burner is 95%, Q is burned with the required air flow rate in the burrock tunnel, and the combustion products flow through the Grid window into the lean tunnel. The pulsator is fed with a "5% of the total combustible gas that is displaced there with air. At the exit of the pulsator mix. diminishes as a result of contact

  with hot burner walls

a tunnel or a torch coming out of it. The burning of a mixture of b koryusyu sator occurs in cotton; the products of combustion with a high rate of speed of the TCO-thermal Box 11, inject the main stream of products of combustion from the burner-tunnel and enter the working chamber.

The increased gas pressure in the pulsator's body during cotton acts on the check valve 14, which interrupts the access of gas and air. The next time the pressure inside the pulsator drops, the valve 14 opens and the ignition process repeats.

The frequency of the pulsations depends on the ratio of the length of the waveguide to its diameter.

In order to stabilize the length of the Waveguide, the walls of the pulsator are made water-cooled, otherwise at glasstheating: the ignition region was re-guiding the tuinene, the mixture approached the place of gas and air supply, i.e. the length of the waveguide was learned. .

At the same time, the ability of gases in the working chamber to conduct oscillations, determined by the wave impedance of the medium pa (p-density medium, oscillation distribution velocity), depends on the temperature, and when the temperature changes in the furnace, the pulsation frequency should also change. For this purpose, the pawl 15 is made with the ability to move along the axis of the pulsators, which will allow Men, the length of the conduit, to maintain the optimum value; the frequencies Kcwi fany.

Piping the 1st FLOW it is advisable to use lshp as an impetus to the movement of combustion products formed during gas combustion in low pressure main breakers, -. .

The effect of hot furnace furnaces, equipped with pulsators, is to improve the uniformity of metal heating as a result of an increase in the recirculation rate of gases, and the intensification of heat exchange due to. pulsating nature of the movement of gases. . ,

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O rm y L a and 3 o b e te n u

Claims (2)

1. A thermal furnace containing a lined working chamber with low pressure burners and a flue exhaust system, so that, in order to improve the quality of metal heating and heat exchange, the furnace is equipped with acoustic oscillation devices exit  burners .. 2.Pech according to claim 1, so that, in order to stabilize the length of the waveguide and control the pulsation frequency, the device of acoustic oscillations is performed in high pressure with gas and air inlets and a plate having the ability to move along its axis, and the pipe walls are cooled. . Sources of information accepted in the review during the examination 1. Pugovkin, A. U. Recycle Flame Burners, M.-L., Matinostroenna 1975, p. 78 .. -X