SU1211565A1 - Chamber furnace - Google Patents

Description

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The invention relates to metallurgical heat engineering and can be used in heating and thermal furnaces of factories of metallurgy and mechanical engineering.

The aim of the invention is to increase the KCh1D of the furnace by reducing the energy consumption of the process,

Razmep5enie gutters in the walls and hearth, interconnected and. with opposite outlets of smoke exhaust ducts, in a staggered order, it allows to organize the directional movement of incandescent combustion products of fuel along these troughs. Such a scheme for organizing the heating of a chamber furnace intensifies radiant heat exchange, which, at a given temperature level in the working space, makes it possible to reduce the energy consumption for conducting metal heating (fuel economy) and increase the efficiency of the furnace as a whole.

Fig „1 shows a furnace, cross section; in fig. 2 shows section A-A in FIG. one; in fig. j) - section UB in FIG. 2 | FIGS. 4 to 5 show temperature profiles in the cross section of the chamber depending on the gas flow rate B, where x is the distance from the receiving surface; x is the distance from the clutch in which the burner is mounted; B (m / h) is: 9.83 (Fig. 4a); 20.73 (FIG. 46); 25.24 (FIG. 5a); 35.34 (FIG. 56); 40.8 (Fig. 5c); in fig. 6 shows the influence of the ratio D of the surface area of the walls, occupied by the recesses, to the area of the walls themselves on the resulting heat transfer Q.

The chamber furnace consists of karka-.

sa i kiln inside walled

refractory brick forming the working chamber of the furnace, bounded by vault 2, with a fiery 1 section installed in it, side walls 4 and a bottom 5. In the side walls 4, along the entire height of the working chamber, vertical grooves of 6 rectangular section are made. In the hearth of the furnace 5, horizontal gutters 7 of rectangular cross section are made, with their pitch being twice as small as the spacing of gutters in the side walls. The transverse grooves 7, located in the hearth, are connected to the grooves 6, located in the side walls, and are covered from above by the area of the bottom with heat-conducting plates that form a continuous worker under the 8 furnace

.

Heat-conducting plates of the razmes: eny 4 furnaces, which are straight to the side walls.

In the side walls of the working chamber below the level of the bases of the horizontal chutes 7, smoke collectors 9 are located, the axes of which are parallel to the chutes 7 connected to smoke smoke inlets 9. The chutes 6 and smoke chutes 9 of one side wall of the working chamber are offset from the chutes and opposite smoke filters with equal steps, i.e. staggered in order. The vest troughs 6 are made with a step of 1.6-3.3 their widths, the wall area covered by the troughs is 0.4-0. Below smoke collectors 9, side smoke walls are located in the side walls: the diverting channels 10 interconnecting smoke extraction 9. In the masonry under the chutes 7 along the longitudinal axis of the furnace (parallel to the side walls) there is a main smoke discharge channel 11 with which the side smoke exhaust channels are connected by transverse smoke channels 12 - one of the furnace ends has a loading and unloading window 13, above which the flap is rigidly fixed 14, Research It has been established that at the exit from the flat-flame burner the layer of gases near the wall has a temperature that is 100-ZOOK higher than the temperature in the main gas volume (Figures 4 and 5). By reducing the mixing of the wall layer with the main gas volume, it is possible to maintain a higher temperature. gases along the entire surface of the masonry compared with the temperature of the main gas volume.

For this purpose gutters are made in the walls. As a result, hot gases are mated in these grooves and the near-wall gas layer heats the masonry more efficiently - the source of tag output to the receiving surfaces.

In addition, direct studies have shown that the resulting heat transfer O „depends on the step

/ via COP

the location of the gutters and the surface area of the walls occupied by the gutters. Fig, 6 illustrates the results of the research.

When reducing the step between the grooves in the side walls less than 1.6 times the width of the non-leg, difficulties arise in the manufacture of masonry of this form,

By increasing the pitch of more than 3.3 times the width of the gutter, a significant decrease in the intensity of the masonry radiation begins, which causes a decrease in the efficiency of the furnace. A decrease in the ratio of the area occupied by the grooves to the area of the total surface of the side walls below 0.4 leads to an approximation of the radiation intensity to the intensity of ordinary smooth walls, and an increase in this parameter above 0.5 causes the construction and masonry of the walls to become more complex.

The furnace works as follows.

Through the loading and unloading window 13 is fed into the work space of the workpiece to be heated and heat treated, which is placed on the surface of heat-conducting plates of the working hearth 5 of the furnace. Heat-conducting materials are designed to prevent wear and deformation of the surfaces of horizontal grooves to which the latter may be subjected during operation of the furnace. In the process of heating and heat treatment of the blanks, the shutter 14 is closed at the loading and unloading window 13

The fuel is combusted using a burner 3, preferably flat flame. At the same time, an open fan-shaped flow of combustion products and a continuous flow past the roof 2 are organized. Next, the fire products continuously wash the surfaces of the side walls 4 and the grooves 6, move along the horizontal grooves 7 of the hearth to the side of the smoke collectors 9 and enter the side exhaust channels 10. The products Combustion, which advance along the surfaces of the left (right) wall, fall into the smoke exhausts of the Opposite right (left) wall.

The flow of combustion products from the grooves 6 of the side walls into the smoke collectors of the 9 walls of the same name is prevented by the snug fit of the working plate 8 to the surfaces of the side walls of the working chamber. Thereby, it is possible to utilize the heat energy of the combustion products within the working space of the furnace as much as possible.

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The hot arch and the side walls of the working chamber are the main sources of heat transfer by radiation from above to the surface of the workpieces. In addition, 5 due to gas recirculation in the working chamber above the blanks, caused by the operation of a flat-plasma burner, convective heating of the upper surfaces of the billet is provided (0. SIDE. Due to the movement of gases under the heat-conducting plates along the gutters to the side of the smoke exhausts, the .

15 The displacement of the grooves 6 and smoke collectors 9 of the same side wall with equal pitch with respect to the grooves and opposite smoke exhausts and dispersed smoke removal, which

20 is achieved, allowing for maximum flushing of all the surfaces forming the working chamber, including those located under the blanks, with gases. Gases

25 they wash the surfaces of the horizontal gutters, which, along with direct convection to the heat-conducting plates, causes radiant heat transfer to them from the gases and the aforementioned

3Q surfaces. In this case, the plates are heated and provide a constant influx of heat to the bottom of the heated blanks.

The described nature of the movement of combustion products in the working space of the furnace provides a high uniformity and intensity of heat supply to the products. Two-sided heating of the blanks can be achieved with one-sided heating of the furnace. This creates favorable conditions for. high-quality heat treatment of products reduces fuel consumption for heating and, as a result, increases. shiva energy efficiency of the furnace. From the side smoke collectors 10 through the transverse smoke channels 12, the products of combustion enter the main smoke outlet channel 11 and leave the furnace. Due to the extensive system of flue channels in the hearth of the furnace, the temperature of the gases leaving the furnace decreases, and the efficiency of fuel use (energy efficiency) increases.

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Compiled by V.Smirnov Editor I.Rybchenko Tehred M.Parotsay Corrector V.Sinitska

Order L32 / 45 Circulation 561 Subscription VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk ia6., d. A / 5

Branch (Shi Patent, Uzhgorod, Project.A, A

Claims (1)

A CHAMBER FURNACE for heating and heat treatment of metal, containing a working chamber 'bounded by a vault, side walls and a hearth of refractory masonry with vertical and horizontal gutters, respectively, on vertical and horizontal sections of the masonry and with smoke exhaust channels in the side walls below the level of the hearth and connected to the gutters, gas burner devices located in the arch, characterized in that, in order to increase the efficiency of the furnace by reducing energy costs for the process, vertical gutters on the side The new walls and the entrances to the flue ducts are staggered, with the distance between the vertical gutters being 1.6-3.3 gutter widths, and the total gutter area of 0.4-0.5 of the total area of the side walls. SU .1211565> 1>. 1