SU855359A1 - Gas furnace section for indirect radiation heating of metal - Google Patents

Description

one

The invention relates to the metallurgical and engineering industries and can be used as an installation for heating a metal before forging, stamping, rolling or heat treating products in a furnace atmosphere with minimal excess air coefficients.

For heating the metal for forging, stamping and other types of plastic deformation, as well as for heat treatment of products, flame furnaces with indirect radiation directional heat exchange are used.

Heating furnaces of indirect radiation heating of metal are known, in which flat-flame burners are used, mounted on the roof of the furnaces 1.

The drawbacks of such a furnace are the complexity of the configuration of burners and burner stones, which require high precision in manufacturing, as well as the high probability of cracks appearing at the joints of the laying of the roof and burner stones at variable thermal conditions of furnace operation. In addition, in furnaces (feedthroughs, methodical) for some modes of operation products

Combustion moving to exhaust channels violates the aerodynamics of the open torch of individual burners until it breaks down.

Closest to the offer is a section of a tunnel furnace equipped with fins. The latter are located transversely relative to the longitudinal axis of the furnace and are made along the height of the side walls and the entire width of the arch. Combustion of fuel is carried out in the zone without ribbing of walls in the whole volume of the working space, and the combustion products move countercurrently to the charge of the charge 2.

However, such a furnace heating system eliminates the possibility of local regulation of heat and chemical (i.e., furnace atmosphere composition) regimes during the process heating of products.

The purpose of the invention is to provide a predetermined distribution of temperatures and heat fluxes along the inner surface of the furnace masonry.

The goal is achieved by the fact that in the walls of the vertical channels are made systems of air nozzles arranged evenly along their height.

The proposed section of the gas furnace has a certain universality, which consists in the fact that each of the sections operates in predetermined and independent from each other thermal and aerodynamic regimes. Furnaces of various types and purposes are compiled from such sections: chamber, semi-methodical, methodical, tunnel with roll-out hearth, etc., operating with a given temperature regime.

FIG. 1 shows the proposed construction of sections of a gas furnace for indirect heating of a metal, a cross section; in fig. 2 - section along the air nozzles BB and the smoke exhaust channels A-A, sections in the plan; in fig. 3 shows the node i in FIG. one.

The section of the working chamber 1, made of refractory masonry, in which there are arch and vertical channels 2, open from the side of working space 1 and separated by ribs 3. To ensure uniform heating of the products, ribs 3 on the opposite walls of the section are arranged in a checkerboard pattern. Burners 4 are installed in the lower part of the vertical channels 2. Gas is supplied to the burners from a common collector 5. Primary air necessary for the start of combustion comes from collector 6, and secondary air used for afterburning of the gas-air mixture comes from the collector 7 to distribution sections ducts 8. The latter are uncooled chambers formed between the outer surface of the masonry and the metal lining of the furnace. The supply of secondary air to the system of nozzles 9 is controlled by the throttle valves 10. Complete combustion products through the exhaust pipes 11 are collected in the smoke collectors 12 and evacuated from the furnace through the channels 13.

The furnace section operates as follows.

The heated products are loaded into the working chamber 1. Gas from the collector 5 is supplied to the burner devices 4. The primary air required for the start of combustion comes from the collector 6. In the lower part of the vertical channels 2 at the hearth, the gas-air mixture with an air excess factor less than 1 begins to burn, 0 Due to the U-shaped design of the channel 2, the combustion of gas is carried out in

a thin layer on the surfaces of the channel walls.

The secondary air required for the afterburning of the gas mixture comes from the collector 7 in the junction box section 8, from them through the nozzle system 9 to the gas combustion channels 2. Each section of the distribution box 8 is a closed space between the outer surface of the furnace masonry and the metal housing. The supply of secondary air at the height of the furnace is regulated by means of throttle valves 10 so as to prolong the combustion, thereby ensuring the specified distribution of temperature and heat flow over the inner surface.

furnace (in the particular case, you can create a uniform temperature distribution over the entire inner surface of the furnace).

The products of complete combustion, washing the arch, are evacuated through channels 11 of the smoke collector 12, then through channels 13 are sent to the furnace heat exchanger. Thus, in the furnace section, the movement of fuel combustion products is provided along the lining. Each channel or system of channels in which fuel is burned operates independently of each other and maintains a predetermined temperature regime by regulating the amount of air supplied, which makes it possible to expand the technological limits of operation of the furnaces.

Claims (2)

1. Forty B.S. Gas industrial furnaces and indirect radiation heating of the metal. M., VNIIEGazprom, 1976. with. 63. 2. The UK patent number 1326585, cl. F 4 B, 1971.