FI61096C - ADJUSTMENT OF ORGANIZATION FOR THE CONSTRUCTION OF DEVELOPMENT - Google Patents

Description

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Wft W (11> UTLÄGGNINOSSKIIIFT 61096 C .... Patent rayannetty 10 05 190 "• (45) v / Patent iroddelat ^ (51) Kv.lk?/lrrt.CI.3 F 27 D 1/16 FINLAND — FINLAND ( 21) P> tinnlhak «mut - PKMitamttknlni 770808 (22) Hik * ml» ptWI - AntBknlngidag lU. 03 · 77 ^ '(23) AlkupUvl - Giltl | h «tid * g 11 + .03.77 (41) Has become public - Bllvlt offentllg 27.09.77

Patent and Registration Office .... , , , . .....

_ *. (44) Date of Nihtlvlkslptnoo and kuuUutkalsun—

Patent- och registerstyrelsen '' Ansöktn utla (d och utl. »Krlft * n publkurad 29.01.82 (32) (33) (31) Pyydetty« tuolktui —B * | lrd prloritet 26.03.76

Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) P 2612912.U-2U

(71) Dörentruper Sand- und Thonwerke GmbH, D-1 + 926 Dörentrup 1,

Federal Republic of Germany (DE) (72) Rudolf Florian, Blomberg, Federal Republic of Germany (DE) (7M Berggren Oy Ab (5I +) Method and apparatus for finishing the smelting furnace - Förfarande och anordning för sl

The invention relates to a method and an apparatus for finishing a melting furnace, in which a refractory lining is provided in the melting furnace by vibrating the pulping mass using a metal molding material. In order to keep the metal model intact so that it can be used over and over again, and at the same time to avoid defects in the finished liner, German application No. 2,414,060 proposes that the metal model be coated with a plastic refractory that hardens at temperatures that cannot damage the metal mucus. and, after vibrating the pulp, the metal template is removed so that the cured refractory during subsequent vibration of the pulp acts as a support for the vibrated pulp.

It has now been found that coating the model with a plastic refractory mass is quite laborious, especially since several work steps have to be performed to obtain a flawless coating. Namely, the required layer thickness is achieved by applying the plastic mass to the surface several times in each case as a thin layer.

The object of the present invention is to considerably reduce the working time required for finishing the melting furnace.

According to the invention, this result is achieved primarily by using thin refractory plates as the coating of the metal template, which are sufficiently flexible to be tightly printed on the surface of the metal template and which are joined together in a refractory manner. In this connection, it has proved expedient to fasten the sheets to each other with a refractory binder.

Coating the metal model with finished sheets is very quick. Their flexibility ensures that they can be pressed tightly onto the surface of the metal model during the vibration phase, so that the vibration effect is effectively transferred to the compaction mass. The refractory binder used appropriately is still flexible during vibration because it does not prevent the plates from settling tightly against the surface of the metal model. Once the refractory binder has hardened, the sheets are firmly joined together, in fact forming a shell which acts as a protection for the sealing compound during its sintering.

It is further expedient to join the sheets together in addition to the refractory binder with tie strips. They allow the boards to be quickly attached to each other temporarily. It is also expedient to place the plates on the metal template overlapping each other and to perform the interconnection at the overlapping entry point.

Plastic-bonded synthetic mica sheets have proven to be a very useful coating.

Until now, it has been common after the lining of a melting furnace to raise its temperature slowly at first, either inductively by means of a large piece of iron of sufficient size to absorb the inductive current of the heating coil, or even by gas. This preheating of the oven takes about 4-6 hours, after which the oven shows a faint red glow.

After this preheating, the furnace can either be filled with molten iron and, starting at a temperature of about 1300 ° C, heated to 1550 ° C and sintered at this temperature, or induction heating can be continued until the iron body melts. Solid metal is then added to furnace 3 61096 and re-sintered at 1550 ° C. The sintering step itself takes about 1-2 hours.

To date, there has been no possibility, given that it is necessary to protect the pulp against deterioration of the structure and the like, to omit the time-consuming preheating step carried out before sintering.

A further developed form of the method according to the invention comprises - the process of pouring molten iron into a newly lined cold furnace.

“It has surprisingly been found that the layer of sheet left over after removing the metal model, especially if the sheets are made of plastic-bonded synthetic mica, can withstand the temperature stress of pouring molten iron into a newly lined cold furnace from a temperature rise involving the expansion of the mass, so long that the molten metal has time to press the vibrated pulping mass sufficiently strongly. It has thus surprisingly been found that the temperature rise of the filling mass actually occurs only simultaneously with the metallostatic pressure applied inside the furnace, so that there is no possibility of the mass expanding towards the furnace interior and forming harmful weak points.

"Thus, due to the metallostatic pressure, the expansion of the pulp due to the temperature rise must be directed backwards inside the pulp, which tends to further condense the pulp - * before sintering. For example, until now it has been the practice to re-line the kiln only at the end of the working week to postpone the normal long production interruption to the weekend, now this new method can be used to re-line the kiln at the beginning or middle of the week.

The device for carrying out the method is shown in partial section in the drawing.

61096

The drawing shows two segments 2 and 3 of a metal model 1 assembled from several segments. The separate segments are assembled into a cylinder by means of star-shaped connecting pieces 5. The connecting pieces 5, which are not in contact with each other, are fastened to the segments with screws 7, and together with the segments they form a smooth-faced cylinder on the outside.

Plates 10 'of plastic-bonded synthetic mica are placed on the outer surface 8 of the template 1 so that they overlap by 60-80 mm. The sheets are joined to each other at the overlapping points by a refractory adhesive 11, and to speed up the fastening, bonding strips 12 are glued on the seams.

When the metal template 1 is coated, vibration of the compaction mass follows. The refractory binder 11 is still flexible at this stage to such an extent that the tightness of the plates 10 'on the surface of the metal template 1 is ensured. The tight adhesion of the plates to the surface of the model causes the vibration effect to be effectively transferred to the Sulon mass. When the vibration step is completed, the metal template 1 can be removed after about 1-2 hours, since the refractory binder 11 is then correspondingly cured. The interconnected plates 10 'now in fact form a shell which acts as a shield in the vibrating pulp during sintering of the pulp.

A mixture of clay, water and a ceramic binder such as aluminum phosphate has proven to be a very useful refractory binder for bonding the plates 10 'together.

The melting furnace can then be finished as described above, namely by pouring molten iron into a freshly lined cold furnace without the need for any preheating.

Claims (9)

A method of final machining of a furnace in which a refractory liner is produced by shaking and sintering of pulp using a metal template and wherein the metal template is covered with a refractory lining which supports the shaken stamp mass and the metal template is removed after shaking. characterized by the fact that, as coating for the metal stencil (1), thin refractory plates (10 ') / which are sufficiently flexible to be pressed tightly against the surface of the metal stencil (1) are used as the coating. are refractory to each other. Method according to claim 1, characterized in that the plates (10 ') are joined together with a refractory adhesive (11). Method according to claim 1, characterized in that the plates (10 ') are further joined together with binder strips (12). Method according to claim 1 or 3, characterized in that the plates (10 ') are placed overlapping pk the metal template (1) and joined together at the overlap site. 5. A method according to claim 1, characterized in that as said coating plates (10 ') of synthetic with plastic mica are used. 6. A method according to claim 1, characterized in that as a refractory adhesive for joining the plates