SU815052A1 - Thermal furnace - Google Patents

Description

(54) THERMAL OVEN

one

The invention relates to ovens for heat treatment of products used, for example, in the metallurgical and metalworking industry.

. Furnaces for heat treatment of products are known, containing at least two thermal zones, with windows of smoke outlets placed in them, burners for heating, guides, splices for unloading products. The discharge zone of such furnaces from the discharge end is directly connected to the quenching tank through the window for dispensing products, and through the slots in the side walls and through the valves in the end walls - with the atmosphere of the workshop. The products are moved in a furnace, the passage is successively thermal zones, and discharged along the slide through the furnaces into the quenching tank pTJ.

The disadvantage of these furnaces is that due to the ingress of vapor from the quenching tank into the furnace space and cold air from the atmosphere surrounding the atmosphere, the working temperature in the furnace decreases, the heated products are heated before quenching, and therefore the quality of heat treatment decreases.

Closest to the present invention is a quenching furnace of a quenching tapping unit containing a heating chamber and an exposure chamber with windows of smoke outlets, burners, a conveyor for transporting products in an oven, and discharging for unloading products. Products move-. furnace in a conveyor, passage in succession to the heating chamber and the exposure chamber. At the end of the holding chamber, the articles slide down into a quenching tank.

Burners are installed in the furnace in the side walls above the discharge window and the smoke exhaust duct windows of the holding chamber are located under these burners at the level of the guides (upper conveyor belt. This is achieved by supplying excess heat to the exposure chamber and withdrawing part of the quenching environment vapor and coolant from the cold air and reduction of undercut before quenching

However, the constant cross-sectional area of the furnace

5 the space of the holding chamber does not create directed circulation of hot flows to the products near the discharge end, and the placement of the windows of the smoke exhaust ducts at the product level

0 leads to the fact that hot gases.

leaving the furnace, they do not have time to give all the heat to the products; at the same time, the cold air drawn from the workshop, directed to the windows, reaches the product to cool them from below. All this does not completely prevent the products from being hardened before quenching.

The purpose of the invention is to improve the quality of heat treatment by eliminating the spinning of products before quenching.

The goal is achieved by the fact that. In a thermal furnace that contains heating chambers and an exposure chamber with windows of smoke outlets placed in them, burners, guides and slides for unloading products, the ceiling of the holding chamber is made with a uniform lift to the discharge window,. over which the burner is additionally installed, and the openings of the exhaust channels of the exposure chamber are located two rows below the guides while the upper row of windows is located in the side walls near the discharge window, and the lower one is directly above the discharge window.

In addition, the cross-sectional area of the smoke exhaust ducts of the side walls of the exposure chamber is 1.52 times larger than the cross-sectional area of the smoke exhaust windows of the ducts located above the discharge window, which ensures an even discharge of cold air drawn from the workshop atmosphere and quenching medium vapors.

Figure 1 schematically shows the proposed oven, a general view; figure 2 - section aa in figure 1.

The thermal furnace contains a heating chamber 1 and an exposure chamber 2 with windows 3 and 4 placed in the chimney ducts, burners 5 for heating, guides b mounted on supports 7, and section 8 for unloading products 9..

The arch 10 of the camera 2 exposure is made with a uniform rise to the load end face 11, in the upper part of which is additionally installed the burner 12.

Windows 3 and 4 of the discharge channels of chamber 2 are arranged in two rows below the level of guides b (and, therefore, of heated products 9, while the upper row of windows 3 is placed in the coftOBiax walls 13 near the unloading window 14, and the lower row 4 windows in the unloading end 11, directly above the unloading window.

The cross-sectional area of the windows of the exhaust channels of the side walls of the exposure chamber is 1.5-2 times the area of the cross sections of the windows of the exhaust channels of the discharge end.

For a uniform suction of waste gas from the furnace, hydraulic soploevlenie smokes karala

must be the same for both hot and cold gases. And since the volume of hot gases in the furnace is larger than the volume of cold gases, the cross-sectional area of the windows for hot gases must be larger than the area of the cross-sections of the windows for cold gases.

More than 2 times this value is impractical due to the fact that the hydraulic resistance of the side wall smoke outlets (for the passage of hot gases) becomes less and part of the cold gases goes there.

Burners 5 for heating and burner 12 ,. installed in the upper part of the discharge end 11, made in the form of short-flare, vortex. The burners 5 are installed in sub-hollow chinks 15 and ensure complete combustion of the fuel within their volume.

Slipper 8 is installed at the end of the camera 2 shutter speed and serves as a continuation of the guides 6.

The guides b and skles 8 for unloading products 9 are made of heat-resistant material.

In the slipway, 8, the windows 16 are made, under which the transverse truck conveyor is installed.

The proposed heat treatment furnace works as follows.

The products 9 before loading them into the furnace are laid on the saddles 18 and together with them move along the guides b, passing in succession the heating chamber 1 and the aging chamber 2. At the end of the chamber 2, the exposures of the product 9 are slid over the slide 8 into the quenching tank 19, and the seats 18 are fed into the windows 16 of the slipway onto the transverse track conveyor 17 of the seats 18.

The circulation of hot and cold streams in the exposure chamber 2 is organized as follows.

Inclined retraction 10 creates flue gas backwaters from the end of the vortex burner 12 and heated products, sending smoke to the upper row of windows 3 of the flue channels, i.e. creates directional cycling of hot streams to products near the discharge window. Cold streams of quenching medium from tank 19 are sucked out through the lower windows 4 of the self-tapping channels. By the upper windows 3, only a small part of it breaks through. The upper row of windows 3 of the flue channels is a dividing line beyond which cold streams of vapor from the quenching tank 19 and drawn air from the atmosphere of the workshop do not flow.

Heat supply to the discharge chamber from the discharge end, the inclined roof, the location of the smoke exhaust ducts in two rows below the level of the guides, as well as the choice of the cross-sectional area of the windows of the smoke exhaust ducts

side walls 1.5–2 times the cross-sectional area of the windows of the exhaust channels of the discharge end minimizes the ingress of cold streams to the products, eliminating churning and improving the quality of heat treatment.

Claims (2)

1. A thermal furnace containing a heating chamber and an exposure chamber with smoke outlets made in the walls, burners, guides, bent, loading and unloading windows, which, in order to improve the quality of heat treatment by eliminating the cooling of the products before quenching, the stove is equipped with an additional burner installed above the discharge window. The arch of the dwelling chamber is made with a uniform rise to the discharge window, and the windows of the smoke exhaust ducts, the exposure chambers are located two rows lower than the direction of the upper chambers, and the upper row of windows of the heating chambers are located in the side walls at the discharge window, and there is a discharge window . 2. Thermal furnace according to claim 1, characterized in that the cross-sectional area of the windows of the flue gas ducts of the side walls of the exposure chamber is 1.5-2 times that of the cross-sectional area of the windows of the flue-discharge channels located above the discharge opening. Sources of information taken into account during the examination five 1. Rustem S.P. Equipment and design of thermal workshops. M., Mashgiz, 1962, p. 281.282. 2. Flame furnaces for various types of heating and heat treatment of metals. Album. M., VNIPI, Teploproject, 1969, №56. fig 16