DD128265B1 - METHOD FOR THE PRODUCTION OF EMBEDDED MEASURES FOR ELECTRIC HEATERS - Google Patents

Description

Title of the invention

'/ learn about the production of Zinbettnaassen for electrical ladders

Field of application of the invention

The invention relates to a method for producing a free-flowing .lasse, which is preferably used for the Zlnbettan electrical heating element in Zlelcfcrowartiegeräten application.

Characteristic of the known technical solutions

Zs is well-known that such Zinbettaassen mostly from Jetall-зігіаэг. scr. The oil products are constructed (iilikattechnik 3 (1352) 2, 5. 77 - 31).

In addition, there is known an experiment in the production of binary beds, in which, in order to improve the workability, the pale special additives, such as phosphoric acid, phosphoric acid, etc., have been added to increase the strength To use addition as well as to improve the workability and to achieve better insulating properties, Cuaa'ze of Zirkono :: 7Q and Antinonpento ^ vd in small! To give to the class (DT-? S 1931 7oi, D ^ -.- G 12-3 772, 3Z-2S 32 973).

2z , Farner is known; electrically insulating wetlands of which the main constituent is quartz sand, with a genic acid of boric acid and / or iodoplatinic acid, as well as: 7d and Ilaolir. Spreclisaal 33 (196ο) 17, p. 451- ^ ЗС) «

Finally, a process for the production of Baulcörpem, tamping compounds and other ceramic products known (DD-PS 35 3o2), in which using chemically pure 35Jjiger phosphoric acid, sand or gravel and clay, a product can be produced that the properties of a high quality clinker has. According to this method, a minimum drying temperature of 45o ° C is required to achieve the formation of aluminum phosphorous necessary for the solidification of bodies. In addition, these pale ones have a relatively high clay content.

The known Sinbettsiassen are characterized by insufficient processing properties, the cause of which is due to the unfavorable granulomeirischen composition. The unsatisfactory processing properties are particularly characterized by poor flowability and sticking phenomena on the pressing tool during the slipping process. Other investment materials show high humidity absorption and insufficient electrical insulation properties due to high levels of free Бог- or phosphoric acid.

Object of the invention

The object of the invention is to improve both the processability of the investment and at the same time their insulation properties en.

Presentation of the Invention's Invention

The invention is based on the technical object to provide a method for the production of Zincettmassen for electrical heating conductors, according to de. An asese can be produced, which is characterized by good flowability, Prsßcarkeit and high isolation ability.

According to the invention, the object is achieved in that a Geaisch from

55 or 53 Geviichtsproaent Quartz sand, grain size o, l - o, 3 nna

2o or 19 "quartz sand, grain size o, o4- o, 3 ш

15 or 14 ⁿ talc, soapstone, finely ground

7,5 or 7 "clay or kaolin, finely ground and

2.5 or 7 "reactive fine grained magnesium oxide

with additions of

0% by weight of phosphoric acid, soft, technical grade and 4 or 5 "7 / a laodo-distilled

optionally with the addition of

3% by weight boric acid, technical

1 ⁿ antimony pentoxide

subjected to processing and subsequent drying at temperatures between 2oo ° C and 4oo G

In a further development of the invention, a corresponding proportion of dilute phosphoric acid is used instead of concentrated 8o% technical grade phosphoric acid and water.

embodiments

The invention will be explained in more detail below using an exemplary embodiment.

- и. -

The preparation of the vaporizable compound takes place in such a way that first the non-plastic, granular constituents, such as brine sand, are mixed with distilled water and phosphoric acid in a mutual relationship with each other. To this C-enisch an addition of feinzn responsive! .Lagnesiumoxyd is added, it enters a spontaneous ITeutralisationsrealrtion with the phosphoric acid, which forms around the grains a shell of JLIagnesiumphosphaten by subsequent addition of plasticizing components, such as clay, kaolin, talc followed by intensive mixing, the formation of another layer and the formation of granules

It is advantageous to provide the composition with boric acid and antimony pentoxide for improved mechanical and electrical strength.

By subsequent addition of talc and possibly boric acid and antimony pentoxide, a crumbly molding compound with granules predominantly in the particle size range of o, 2 - o, 5 mm- Ss is appropriate to use talc of a low iron and alkali low tone. The Pormgebung can be done for example by dry pressing at temperatures of 2oo ° C to 4oo ° C, whereby the strength and the electrical properties of the investment are improved.

Claims (2)

ISrfindungsanspruch 1. A process for the preparation of investment materials for electrical heating conductors of the main ceramic components with binder addition vsobei a mixture of non-plastic grains, phosphoric acid, water and T ^ gnesiumosid is added to earth, this mixture mixed with plasticizing ingredients, mixed, subjected to molding by dry pressing and then dried , characterized in that a mixture of 55 or 53 weight percent quartz sand, grain size o, lo, 3 mm 2o or 19 "quartz, grain size o, o4-o, 3 mm 15 or 14 ^w talc, soapstone, finely ground 7.5 or 7" clay or kaolin, finely ground and 2 , 5 or 7 "reactive fine-grained magnesium oxide with suspensions of 6% by weight phosphoric acid, SoiSig, technical, and 4 or 5 "water, monodestillated if necessary with the addition of
3% by weight of boric acid, technically 1 "antimony pentacide is subjected to the processing and the subsequent drying is carried out at temperatures between 2oc ° C and 4oc ° C. 2. The method according to item 1, characterized in that instead of concentrated 8o% iger technical phosphoric acid and "" .'asser, зіп corresponding proportion of dilute phosphoric acid is used »