SU1673810A1 - Muffle electric furnace - Google Patents

Abstract

The invention relates to electrothermal equipment and can be used for heat treatment of wire, strips, roll tapes. The purpose of the invention is to simplify the design by facilitating wire filling and reducing energy loss by introducing additional heat insulation into the muffle. The electric furnace includes a lined casing (K) 1 with loading and unloading windows. Inside K 1 there is a muffle (M) 4 with bypass rollers 6 installed in windows located in the upper part of K 1 and M 4. The cavity M 4 is tightly filled with a flowing coolant 10. The invention improves the heat treatment efficiency by eliminating oxidation of the material being processed, reduces consumption protective gas, and also allows to reduce production areas. 2 hp f-ly, 2 ill.

Description

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The invention relates to electrothermal equipment and can be used for heat treatment of wire, metal strips, roll tapes and other technological materials.

The aim of the invention is to simplify the design by facilitating the filing of the wire and reducing energy loss by introducing additional heat insulation into the muffle.

FIG. 1 schematically shows a muffle electric furnace, a longitudinal section; in fig. 2 - the same, cross section of the furnace.

The electric muffle furnace contains a casing 1 with a lining 2 and loading and unloading windows 3. Inside the casing 1 there is a coaxially located muffle 4, the walls of which are covered by heaters 5, while the furnace is equipped with guides 6 and a lid 7, which in the working position has gaps 8 with a casing 1. Loading and unloading openings 3 are made in the form of longitudinal slits in the upper part of casing 1 and muffle 4, and guides 6 in the form of bypass rollers installed in windows 3 in the path of movement of the processed material 9. The cavity of muffle 4 is tightly filled get coolant 10, such as corundum.

Corundum with a particle diameter of 1-2 mm was used as a heat carrier. The gap between the furnace lid and the casing plane is 3-5 mm, which provides an outlet for the excess vapor-gas mixture.

The electric works as follows.

After the heaters 5 are turned on and the furnace is heated to operating temperature, for example, 850–950 ° C, the wire is pulled through the muffle 4, moving from the delivery unit to the receiving unit relative to the guide rollers 6 under the cover 7, the passage of the slot 3 of the case 1 and the muffle 4 In this case, the wire comes into contact with the bulk heat transfer medium 10, such as corundum, and heats up according to the speed of movement to a predetermined temperature. Periodically, the heaters 5 supported by the temperature sensors are turned off, and the temperature inside the muffle is kept constant due to the good heat capacity of the heat transfer fluid 10. The muffle 4 is filled with material as well as heat carrier 10 through the longitudinal slots 3 with the lid open 7.

Windows 3 compensate for internal stresses arising in the cavity of the muffle 4. Making the loading windows in the form of longitudinal slits in the upper part of the casing and muffle simplifies the design by the fact that the loading windows reduce the number of covers and also do not require completing the entrance and output holes with cylindrical guides built into them

and ceramic washers. The longitudinal slits allow the muffle to be introduced into the cavity not only by the material being processed, for example, wire, but also by free-flowing coolant. Use in a cavity a muffle loose

the heat carrier eliminates the need to maintain a complex lining, namely refractory and thermal insulator backfill, separated by a perforated screen, as well as a protective coaxially installed tube.

In turn, sealing the muffle and densely filling its cavity with a free-flowing coolant, such as corundum, helps reduce energy costs.

for heat losses, since the proposed coolant has a high heat capacity, and sealing the ends of the muffle reduces the consumption of heat energy.

Along with this, the proposed bypass

rollers, as guides of the processed material, installed in the path of its movement, also contribute to the simplification of the construction as a whole. Their installation above the housing slots simplifies the path of movement of the material being processed and allows you to silence the ends of the casing and muffle, which reduces the number of structural elements.

Compared with the prototype, the proposed muffle furnace increases the efficiency of heat treatment, eliminates oxidation of the material being processed, reduces the consumption of protective gas, and also allows reducing the production area.

The device is recommended for continuous heat treatment of tape-wound materials, drying of yarns, cords, various technological

raw materials and can work in the range of drying temperatures of practically from 50 to 950 ° C.

The use of the proposed device will exclude, for example, during heat treatment of galvanized wire, a pickling tank, which will improve the environment by eliminating harmful substances into the atmosphere, improving the sanitary condition of workshops and occupational safety.

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Claims (3)

1. Muffle electric furnace for heat treatment of wire containing a lining casing with loading and unloading windows and a lid, heater, muffle, guides, characterized in that, in order to simplify the design and reduce energy losses by introducing additional thermal insulation, loading and unloading windows are made in the free part of the casing and muffle, are made in the form of immersed in coolant bypass rollers installed in the loading and unloading windows. 2. Electric furnace according to claim 1, that is, that the bypass rollers are fixed on the cover. 3. Electric furnace according to claim 1, that is, with the fact that the coolant is made of corundum. 2