SU1206590A1 - Continuous furnace for metal monoxidation preheating - Google Patents

Description

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The invention relates to high-temperature furnaces for oxidation-free heating of a metal with two stages of fuel combustion and can be used in the metallurgical and engineering industries.

The purpose of the invention is to improve the quality of jagreva due to a more complete separation of the afterburning products and the protective layer over the metal and eliminating the decarburization of steel during heating.

The drawing shows schematically the design of the furnace, a longitudinal section.

A pass-through furnace for non-oxidative heating of the metal contains a roof I, on which are flat burner burners 2, bottom 3 and transverse pipes of system 4 with colds 5. Water-cooled pipe 6 with ribs 7 passes through the tubular system, and the entire system is loop-shaped in the case of large width of the working space heat-insulated water-cooled suspensions 8. In the longitudinal walls along the entire length of the working space, protrusions 9 are made, and the smoke window is located in the arch at the loading end of the furnace,

 The transverse tubes are spaced apart from one another in increments of 8 d S and lOd.

The tubular elements consist of two concentrically arranged tubes. Water flows through the outer pipe. Three longitudinal ribs are welded to its outer surface at an angle of 120. In the space between the pipes, depending on where they are located, there is a mix of natural gas with air, pure natural gas and a mixture of natural gas with ten percent impurity of butane. The mixture enters the working space through slit nozzles with a section of 10 x 150 mm made in the wall of the outer pipe under different directions to the direction of metal movement. The tubular structure on the section O i-L, 4 0.21, counting from the loading window, is absent on the section 0.21 L s 0.6L, the nozzles of the tubular structure are at an angle of 45 ° 50 to the hearth for supplying a mixture of natural gas with air 0.4-0.45, on

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The 0.6 L L ,, 4 0.9 ′ section of the nozzle is located at an angle of 20 ° t ъ 25 to the hearth, and the pipe with a mixture of natural gas with air at 1

5 0,4-0,45 series with a pipe supplying pure natural gas, and in the section 0.9 U t C the nozzles are located at an angle Y5 ° 80 ° to the hearth for supplying natural gas with

10 ten percent of the butane impurity, where U is the length of the furnace.

The value (selected within these limits to abruptly cut off the flow of oxidizing gases located on

15, the dCj value, to maintain a non-oxidizing atmosphere, and the sharply directed A value, to partially carburize in the middle of the 20th section.

With a decrease in L a, the cut-off of the stream of oxidized gases decreases, and with an increase, recirculation flows arise at the surface of the metal. Decrease cX. It also reduces the flow cut-off, and the increase contributes to the erosion of the non-oxidizing atmosphere. Keenly directed. the nature of the nozzles with a tilt angle

2Q contributes to partial carbonization. Reducing the angle reduces carburization, and the reduction leads to an increased carbon content in the surface layer of the metal. The spacing is 150–120 mm from the other.

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The furnace works as follows. Through the vault burners, a mixture of gas and air is fed at an air flow ratio n 1,, 3. The products of complete combustion resulting from the combustion of this mixture fill the upper part of the working space in which it mixes with.

the products of incomplete combustion coming from the bottom ensure their afterburning and full utilization of thermal energy. Through a nozzle. Cross pipes on the metal serves a protective atmosphere. The resulting products of incomplete combustion protect the metal from decarburization. The presence of lateral protrusions and the location of the smoke window in the code at the boot end contribute to a good separation in the working space of products of incomplete and complete combustion.

Claims (1)

THROUGH FURNACE FOR A NO30 OXIDATIVE HEATING OF METAL by ed. No. 855360, excellent. This is due to the fact that, in order to improve the quality of heating due to a more complete separation of afterburning products and the protective layer above the metal, slotted nozzles for supplying protective gas are installed, starting from the entrance to the furnace, in the furnace section 1 0.2-0 , 6 ') b at angle. scrap 45 - 50 °, in the furnace section (0 / 60.9) and - at an angle of 20 - 25 and in the furnace section (0.9-1.0) Li - at an angle of 75 - 80 ^е , where b is the length of the furnace . _ 1 1206590