SU946011A1

SU946011A1 - Tubular electric heater

Info

Publication number: SU946011A1
Application number: SU802886942A
Authority: SU
Inventors: Эдуард Рахимович Галиев; Семен Вениаминович Некрутман; Олег Александрович Цветков; Геннадий Васильевич Кошман
Original assignee: Московский Ордена Трудового Красного Знамени Институт Народного Хозяйства Им.Г.В.Плеханова; Харьковский Институт Общественного Питания
Priority date: 1980-02-25
Filing date: 1980-02-25
Publication date: 1982-07-23

Description

(54) ТРУБЧАТЫЙ ЭЛЕКТРОНАГРЕВАТЕЛЬ (54) TUBULAR ELECTRIC HEATER

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Изобретение относитс к электротермии , в частности к трубчатым впектронагреватеп м с реэ стивными проволо ными элементами.The invention relates to electrothermal, in particular to tubular latent heat and m with resistive wire elements.

Известны трубчатые электронагреватели , содержащие металлическую оболочку и спиральный нагревательный элемент, изолированный от стенок трубы nocpef ством наполнител l .Known tubular electric heaters containing a metal sheath and a spiral heating element, insulated from the pipe walls by means of a filler l.

Вследствие недостаточ1 о равномерного контакта между сшфалью и наполнителем происход т местные перегревы спиparai , что приводит к преждевременному выходу из стро нагревател .Due to insufficient contact between the salt and the filler, local Spirparai overheating occurs, which leads to premature failure of the heater.

Известны .также трубчатвю электрюнагреватели , содержащие металлическую оболочку, спиральный проволочный ре- знстивный элемент, изол ционный наполнитель и дополнительное электроизол ционное покрытие, выпопнешюе на основе стекла, примыкающее к поверхности резистивного элемента 2 j.Also known are tubular electric heaters containing a metal sheath, a spiral wire resistance element, an insulating filler and an additional electrically insulating coating, made on the basis of glass, adjacent to the surface of the resistive element 2 j.

Недостатком нагревател вл етс мала надежность, дополнительное тер мосотфот впение между резистивным элементом и наполнителем.The disadvantage of the heater is its low reliability, the additional termosothot is the penetration between the resistive element and the filler.

Целью изобретени вл етс улучшение эксппуатацисшных характеристик за счет улучшени теплотехнических характеристик нагревател , надежности и долговечности нагревател путем снижени термосотфотивлени дополнительного покрыти .The aim of the invention is to improve the performance characteristics by improving the thermal performance of the heater, the reliability and durability of the heater by reducing the heat resistance of the additional coating.

Указанна цель достигаетс тем, что в дополнительное пок1н 1тие введены кол поненты изол ционного наполнител , а именно сжись магни и окись кальци , н компоненты дополнительного покрыти вз ты в следующем соотношезнии, мае. %: Стекло 5О - 55This goal is achieved by the fact that the insulation insulating filler components are added to the additional product, namely, magnesium and calcium oxide, and the components of the additional coating are taken in the following correlation, May. %: Glass 5O - 55

Окись магни 25 - 30Magnesium Oxide 25 - 30

Окись калыш 20 - 25Oxide Kalysh 20 - 25

причем температура плавлени покрыти выше рабочей температуры резистивного элемента.wherein the melting point of the coating is above the operating temperature of the resistive element.

Claims

FIG. 1 shows a heater, a longitudinal section; in fig. 2 - resiotic element, cross section. 3 & The tubular heating element contains a metal sheath 1, a spiral wire resistive element 2, an insulating filler 3 and an additional electrical insulation layer 4, made on the basis of glass, adjacent to the surface of the real element 2. The resistive element 2 is connected to the outlets by its ends rods 5, with the help of which, as well as with the help of nuts and washers 6 and 7, are connected to a source of electrical voltage. Sealant 8 and insulator 9 protect the coil from water, oils, and gases. The electrically insulating coating 4, adjacent to the resistive element 2, is made of an amorphous plastic substance with a melting point higher than the heating temperature of the resistor in working condition and the grains of crystalline insulating filler 3 pressed into it. The additional coating is carried out by immersing element 2 into the previously prepared insulation of the mixture of glass and components of the insulating filler, namely magnesium oxide and calcium oxide, and in liquid CONDITION after uyuschim COOTnoscheniem components, May. %: Glass 50 - 55 Magnesium Oxide 25 - 30 Calcium Oxide 20 - 25 "Reducing or increasing the amount of glass will complicate the technology of preparation of the mixture, will not provide thickness to the uniformity of the coating layer. The percentage of magnesium oxide and kalycium oxide provide the maximum thermal conductivity and its dielectric properties. After the helix is immersed in the mixture, it is allowed to stand out of these compacts in air at 15–25 ° C for 5–8 min, then the helix is placed in a shell, which is filled with filler. In the process of crimping the tube, the filler (perclase) is in close contact with the coating applied to the spiral. This ensures reliable heat removal from the entire outer surface of the helix and heat transfer from the helix and the inner surface of the heater sheath. 1 The melting point of the coating exceeds 12OO C due to the composition of the mixture of oxo magnescane. When the current flows through the resistive element, the latter heats up and through a secondary coating providing good heat transfer between the elastic element and the periclase, it gives off heat to the metal shell. Due to the organization of an intense heat removal from the resistive element to the shell of the tubular heater, its release time is reduced from 3.5 missions to 2 missions. The use of an additional electrically insulating coating, built-up on the basis of glass and the supporting components of the insulating filler, namely magnesium oxide and calcium oxide, allows to increase the thermal conductivity of the coating, and by increasing the uniformity of heat removal from the helix and reducing the temperature difference between the helix and the shell to improve the reliability of heaters. Claims of invention The tubular electric heater containing a metal sheath, sp-. Ralled resistive wire element, insulating filler and additional electrically insulating coating performed on glass glass adjacent to the surface of the resistive element, characterized in that, in order to improve the performance of the electric heater, insulating filler components, namely magnesium oxide, are added to the additional coating and calcium oxide, and additional coating components are taken in the following ratios, May. %: Glass 50-55 Magnesium oxide 25 - 30 Calcium oxide 20 - 25 and the melting point of the coating is higher than the operating temperature of the resistive element. Sources of information taken into account for the examination 1. Authors certificate of the USSR No. 431650, Yu1. H 05 B 3/48, 1974.

2. US patent number 3716693, cl. H O5 B 3 / 1O, 1973.