SU1394016A1 - Heating furnace hearth - Google Patents

Abstract

The invention relates to heating furnaces, in particular furnaces for heating a metal before pressure treatment, and can be used in the metallurgical, engineering and other industries. The aim of the invention is to increase the productivity of the furnace. For this, under the heating furnace there are made with channels 2 for the passage of heat carrier, each of which is formed by a cylindrical surface 9 of the refractory base 1 of the hearth and the bottom surface 10 of the bottom plate 3 laid on the refractory base 1. The cross section of the channel 2 is filled in a segment with a constant radius with the ratio of the length of the arc J to the height h (0.85-2.0) | G. 3 ill., 1 tab. with $ W

Description

ЦУ /////////////////////// 7

CO with

four

O5

shigl

The invention relates to heating, in particular, furnaces for heating a metal before pressure treatment, and can be used in metallurgical, machine-building and other industrial sectors.

The aim of the invention is to increase the productivity of the furnace.

Fig. 1 shows a methodical furnace with a channeled hearth, a cross section; Fig, 2 - section -A in Fig 1; in fig. 3 - part with one channel, cross section.

Under contains a refractory base with channels 2 for the passage of the coolant and laid on it the bottom plate 3, made of vyvopotrovodnogo material. It is a structural element of a heating furnace with a working space 4 bounded by walls 5 and a roof 6. The channels 2 in the refractory base 1 of the hearth are located along the hearth and are connected at the beginning of the furnace at the burner with working space 4, and at the end of the furnace 8. Each of the channels 2 is formed by a part of the cylindrical surface 9 of the refractory base 1 and the bottom surface 10 of the bottom plate 3. The cross section of each channel is made as a segment with a constant radius with a ratio of length 1 arc LAN (FIG. 3) to the segment height h is equal to (0,85-2,0) 7 "

I

The ratio is defined by

less

experimentally (table).

I found that with -

0.85 IT due to the small value of the angular radiation coefficient and the developed surface of heat exchange between the channels and the base of the heat loss

significant, growth i

1 - no nosti. With respect - more than 2 (/

due to the reduction in the flow area of the channels, the heat transfer from the heat carrier to the bottom plate decreases, and the heating degree of the plate does not increase performance.

Experimentally determined prep

Cases - (0.85-2, o) are optimal.

ten

15

20

25

thirty

35

40

45

50

55

Example. The furnace is equipped with a hearth with a base made of fireclay. At the base of the hearth, 46 channels are made, located across the entire width of the hearth and connected at the entrance to the furnace working space in the high temperature zone and at the outlet to the smoke outlet. On the refractory base laid stove plate, made of silicon carbide with a thermal conductivity of 27.2 W / m deg. In addition, each of the channels is a part of a cylinder formed by the surface of the chamotte base of the hearth and the lower surface of the bottom plate.

The channel cross section is a segment with an arc length I of 0.245 m and a height h of 0.065 m.

g

The ratio is 1.21 /.

Under works as follows.

A part of the coolant (hot flue gases) with a temperature of 1200 ° C due to the pressure difference in the working space 4 and the smoke exhaust well 8 enters the channels 2 and moves along them, heating the cylindrical surface 9 of the refractory base 1 and the bottom surface 10 of the bottom plate 3. Lower the surface of the heated metal 7, laid on under, has a temperature respectively along the length of the hearth from the entrance to the exit of the furnace 20 ° C - 1100 ° C, the cylindrical surface 9 of the channels 2 900-1200 ° C, the bottom plate 880-5200 ° C. The available temperature gradient provides directional heat transfer from the base plate 3 to the heated metal 7 and from the cylindrical surface 9 of the refractory base 1 to the bottom surface 0 of the bottom plate 3, 1

Under the implementation of the channels in cross section in the form of a segment, it allows to intensify heat transfer by radiation from the cylindrical surface 9 of channel 2 to the surface 10 of the bottom plate and to increase the furnace productivity by 5-8% "

Claims (1)

Invention Formula Under the heating furnace, containing a refractory base with channels for the passage of the coolant and a plate of high-conductive material, characterized in that, in order to increase the performance of the furnace, each of the channels for the passage of the coolant is formed the bottom surface of the slab, while the cross section of the channel is made in the form of a segment with a constant radius part of the cylindrical surface of the arc length to the height {0.85-2.0) TG. Bottom construction with rectangular channels 0.7 1-25 1t22 1g25 1-30 the bottom surface of the hearth plate, with the cross section of the channel made in the form of a segment with a constant radius at a ratio of 65, 0 Unsatisfactory, low productivity of the furnace Unsatisfactory, due to the small value of the angular radiation coefficient and the developed heat exchange surface between the channels and the base of the heat loss is significant, there is no performance increase Satisfactory, furnace productivity increases.: By 5-6% Good kiln performance increases by 8%. Satisfactory, furnace capacity increased by 5-6% Unsatisfactory, due to the reduction in the flow area of the channels, the heat transfer from the heat carrier to the bottom plate and the heating rate of the plate decrease, there is no performance increase m.2 Compiled by G. Kolchenko Editor G. Gerber Tehred L. Serdyukova Proofreader L. Pilipenko Order 2206/35 Circulation 560 VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 FIG. Subscription