SU885766A1

SU885766A1 - Conveyer furnace

Info

Publication number: SU885766A1
Application number: SU792777848A
Authority: SU
Inventors: Андрей Георгиевич Зеньковский; Виктор Александрович Давыдов; Вячеслав Васильевич Костяков; Роман Шмулевич Митнин; Александр Васильевич Аксенов
Original assignee: Московский вечерний металлургический институт
Priority date: 1979-06-28
Filing date: 1979-06-28
Publication date: 1981-11-30

Description

1one

Изобретение относитс к нагревательным устройствам металлургической и машиностроительной промьштенностей и может быть использовано при термообработке металла.The invention relates to heating devices for metallurgical and machine-building industries and can be used in the heat treatment of metal.

Известна композици индукционной печи дл нагрева заготовок, содержаща индуктор, механизмы загрузки и выгрузки Ю.A known induction furnace composition for heating the preforms, comprising an inductor, loading mechanisms and unloading units.

Основным недостатком печи вл етс ее низкий тепловой коэффициент полезного действи , так как при нагреве заготовок через открытый индуктор возникают большие тепловые потери излучением в окружающее пространство . Вследствие этого снижаетс и величина общего КПД печи, включающего в себ электрический и тепловой коэффициенты.The main disadvantage of the furnace is its low thermal efficiency, since when the blanks are heated through an open inductor, large heat losses due to radiation into the surrounding space occur. As a consequence, the overall efficiency of the furnace, which includes electrical and thermal factors, is reduced.

Наиболее близкой по технической сущности к предлагаемой вл етс проходна печь, содержаща камеру нагрева с футеровкой и теплоизол цией , индуктор t2.The closest to the technical essence of the present invention is a through-furnace, containing a heating chamber with a lining and thermal insulation, inductor t2.

Дл .снижени тепловых потерь индуктор печи отделен от камеры нагрева слоем футеровки. Однако выполнение футеровки значительной толщины в такой печи существенно снижает электрический КПД, так как напр женность магнитного пол , создаваемого индуктором, падает с увеличением рассто ни от индуктора до поверхности заготовки. При этом снижаетс To reduce heat loss, the furnace inductor is separated from the heating chamber by a lining layer. However, the implementation of a lining of considerable thickness in such a furnace significantly reduces the electrical efficiency, since the intensity of the magnetic field created by the inductor decreases with increasing distance from the inductor to the surface of the workpiece. This decreases

10 и общий КПД. В случае применени футеровки малой толщины, резко снижаетс тепловой КПД, так как увеличиваютс тепловые потери. Следовательно , получать высокие значени 10 and overall efficiency. In the case of the use of a lining of small thickness, the thermal efficiency decreases sharply, as the heat loss increases. Therefore, to obtain high values

IS общего КДЦ печи при изготовлении ее с обычной футеровкой не представл етс возможным.An IS of a total QDC in the manufacture of a conventional lining is not possible.

Цель изобретени - снижение тепловых потерь через огнеупорную фум теровку.The purpose of the invention is to reduce heat losses through the refractory fum terovku.

Claims

The goal is achieved by the fact that on the inner surface of the lining along the length of the kiln, trapezoid-shaped grooves are made with the ratio of the main trapezoid h / h 2: 2.2v, depth 2.5-2.8h, arranged in increments; 1-1, 2h, where h - pain - the smaller base of the trapezium and the base of the trapezium. . On f. 1, a furnace is presented, about a longitudinal section} in FIG. 2 - a section A-A in FIG. one . In the pass-through induction furnace, blanks I are loaded into a heating chamber 2 having a refractory lining 3, made with trapezoid-shaped grooves 4, and thermal insulation 5. Heating the blanks is carried out using an inductor 6. Experiments conducted with fire resistant materials made with different grooves, show that the heat loss through the lining is lower, the deeper the groove. In this case, the equivalent thermal conductivity of the layer of refractory containing the grooves is lower than the thermal conductivity of the fire it's time. However, increasing the depth of the coil above the values of 2.8S, where h is the width of the groove, is impractical, since in this case the strength of the lining decreases. In the case when the depth of the groove is less than 2.5h, its effective emissivity decreases sharply, which greatly reduces the amount of radiant heat transferred by the deposit to the metal. In addition, experiments confirm the conclusion that the maximum emissivity of the refractory lining and the minimum heat loss through it are determined by the density of grooves on its surface. The optimum ditch spacing corresponds to 1-1.2 h, since with a smaller step the performance characteristics of the refractory lining are significantly reduced (the heat resistance decreases by 15-20%), and at. 4 in a larger step, the effect of using grooves to reduce heat losses is negligible. The determination of the optimal shape of the groove located on the surface of the refractory is carried out by the amount of heat loss through the lining. In this case, minimal heat losses are observed in the case when trapezoidal grooves with the ratio, 2 are made on the inner surface along the furnace. In this case, the greatest uniformity of temperatures is achieved on the radiating surface of the lining. As a result of using a groove lining, the overall efficiency of the furnace is increased by l-gd (Chad electric efficiency} compared to the efficiency of an induction furnace having a lining without grooves. As a result, the power consumption per induction furnace is reduced, which allows to obtain economic efficiency, while replacing the furnace lining 2430 rubles / g with a conditional capacity of 1 t / h. I Formula of the invention A passage furnace comprising a heating chamber with a refractory lining and thermal insulation, an inductor, characterized in that, in order to reduce thermal losses through the refractory lining, on the inner surface of the lining along the length of the furnace Trapezoid-shaped grooves with a trapezium base ratio h / h., 2: 2.2; 2.5-2.8 h deep and in steps of 1-1.2 from the larger trapezium base Sources of information taken into account during the examination 1. Lebedev, IS, Telegin, AS, Heating Furnaces, Mashgiz, 1962, pp. 281.

2. Krivandin V.A., Markov B.L. Metallurgical furnaces. M., Metallurgists, 1977, p. 439.