DE1458914B1 - Method for lining furnace surfaces - Google Patents

Description

1 2

The invention relates to a method for the preparation of refractory material suitable mixing

and for spraying a refractory feed boiler, which is large because of the required heating system,

on the hot inner surfaces of an oven. were heavy and immobile. If the silica

Because of the high temperature that chemical soda had once gone into solution and the Actions to which thermal and mechanical 5 required refractory slurry was reached, Then chipping, the refractory linings wear themselves out which could take considerable time of furnaces and therefore need frequent repairs and had to put the slurry in from the mixing vessel to be renewed. Originally a spray gun had to be transferred for such a device, which then Repairs the furnace was shut down and cooled down to the various parts of the furnace, so that the necessary repairs and io therefore claimed such a procedure Renewals to the lining or lining considerable equipment, time and expense, could be carried out from within. The object of the invention is to eliminate the known causes Significant cost because of the cool down time of those involving a sticky silicate solution Most stoves are quite long. refractory particles is mixed to improve.

These disadvantages are alleviated by known methods. In particular, the object of the invention is

avoided where the refractory material on which the manufacture of the sticky silicate solution is essential

Internal surfaces is sprayed on. To simplify the refractory material.

is sprayed on from outside through access openings, according to the invention with the help of under

d. That is, the furnace can repair the silicate in a hot state, pressurized steam will. This technique was particularly well suited to the sticky solution transferred with the refractory

for Siemens-Martin ovens, electric ovens and ba-particles mixed into a sprayable suspension

sic stoves. will.

According to the known method, particles are thereby succeeded with the help of a movable Made of refractory material with a dry binding spray device, the refractory mixture immediately medium and water floated and spray on the 25 on the inner surface of the combustion chamber Surfaces of the furnace sprayed. As a binding agent and thereby the application are essentially too common adhesive silicate materials and simple and cheaper. The mixing tank for the special silica soda is used. The water production of the suspension can be close to the loss hardens the adhesive silicates. The adhesive ■ must be installed in the oven and with a spray device Silicic acid soda offer the advantage of being able to move around. The suspension will good distribution and good contact, one suitable for application with a gas large areas - controllable amount of deposit mixes to enable spraying and the formation of a stable, strong and solid one. For a better understanding, the invention is now Bond that is water and heat resistant. In the case of the described on the basis of drawings. In the known systems, a large mixing tank was shown with 35 drawings

with dry silica and dry F i g. 1 a vertical section through the mixed refractories Particles filled, then water added, and spray device described in the present invention to dissolve the silicic acid soda and use a charge,

slurry from the solution and the refractory F i g. FIG. 2 is a plan view of the device of FIG

Particles to form. However, soda silica is 40 F i g. 1.

extremely difficult to solve. According to the present invention, silicates are first of all glasses, which are prepared as a melt from quartz sand ^T a solution of silicic acid soda, and sodium or potassium carbonate are then produced with the refractory particles in the spray nozzle. The resulting glass is mixed into small jig blocks. The previously loosened pebble formed, then broken into sticks or ground up. 45 Sour soda and the refractory particles are transported separately to the point where they are to be used to dissolve the silica glass. Then the solution is used out, the alkali can be leached out, silica fats with the refractory particles and a network of insoluble silica remains. mixed in a small mixing kettle, one back. On the other hand, if water is used, 50 forms part of the sprayer. Since the silicic acid, which has already been partially dissolved in the sodium silicate, is held in the mixing tank, the alkali is not leached out, and the silicic acid no heat, no time to dissolve the silicic acid sodium bicarbonate goes into solution, and that Ratio of natrons required and the slurry of Na ₂ O and SiO ₂ in the solution is not the same from the mixing kettle to the sprayer as in the glass. - ■ 55 be ported.

The process of dissolving the silicic acid soda As mentioned above, silicic acid sodium bicarbonate dissolves consists initially of a hydrogenation. Therefore must in a special way. It dissolves in a little between the surface of the glass particles and the amount of water actually better than in a larger one. Water can undergo a chemical reaction in which it is best dissolved with steam and under pressure, the surface of the solid phase becomes hydrated. 60 The steam makes its way into the silica As well as then the silicic acid soda from the top soda, condenses, hydrates and dissolves it closing surface goes into solution, hydration proceeds. borrowed. The special ones to solve this material Until a saturated solution is reached, it can depend on the techniques used and the application to it depending on the circumstances, hours or even days at any point in the furnace did not last economically. 65 will fit. Therefore uses the present

Heat increases the solubility and the solution invention commercially prepared, previously dissolved

speed of sodium silicate, and sodium silicate. It turned out that

half used the well-known processes for refractory materials, which with this form of a silicate

adhesive are prepared, ideally to the furnace. During operation, the mixing and injection unit

stick to walls. arranged adjacent to an opening of the furnace.

A commercially available solution of silicic acid. The ingredients are introduced through inlet port 20

Soda has the following properties: brought in, and then the unit is sealed.

5 The mixer is then started and

Ratio of Na ₂ O: SiO ₂ 1: 2.00 f ^{nd d} ^ spraying kept in operation around the fire

slurry solid material and use it as a

% Na ₂ O 14.70 to keep slurry. However, if the viscosity

% SiO ₂ 29.4 of the sodium silicate solution used

. 'ίο is so big that the once mixed refractories

Degrees Baume at 20 C 50.5 particles for a considerable period of time.

Viscosity, centipoise at 2O ⁰ C 350 remain moderately distributed, the mixer can

üH value about 12 can be switched. Therefore the spray gun can too

Can be used where no electrical connection is available for the mixer. Another-

This particular solution is just an example. On the other hand, an air motor could be used for the mixer, many solutions of silicic acid are still used and obtainable through the baking soda used for spraying, which is driven by compressed air for the refractory binding agent. If a suitable one of the present invention were suitable. Such a degree of mixing has been achieved, the ven solutions have different ratios of Na ₂ O 20 to 74 opened and the space above the sludge in the SiO ₂ , different water content and Baume boiler is pressurized and so the sludge degrees. Also, siliceous potash could just as easily be squeezed out through tube 62. Then that like silica silica, will be used. The valve 78 is set so that an appropriate amount of air refractory particles mixed with the solution can be mixed with the slurry at the connection 63 of the line 64 from any conventional tube 62. A suitable refractory material in a finely divided state. Air pressure in the boiler is z. B. 7 kg / cm ² , although they are standing. Chromium-based refractories or unit magnesite-based materials also operate at other pressures are two examples, and they can. Because the air is more likely to be used at the beginning of the pipe 62 in grain sizes from 45 to 1000 μ. as it mixes with the material at nozzle 59, the granule size is not so important and the flow rate of the slurry through the indicated area is only an example. As the lines 64 and 67 are raised, other usable refractory materials remain as the refractory particles are obtained as a slurry are made of materials on dolomite and aluminum and do not fall out.

oxide base. The selection of certain refractory materials can, according to the present invention, be

materials is not part of the present invention- 35 different degrees of heat are injected as long as fertilization, but rather depends on which areas to be sprayed are accessible. To the refractory substrate they are applied. Example can also do that directly with electric ovens

A typical approach to reconditioning the swept-molten bath after tapping and as well me would consist of 145 kg of finely divided chrome or be sprayed after cleaning. At this time refractory material, 29.5 kg of the aforementioned 40 point, the furnace has temperatures of 1427 to Solution of silica and soda from 37.851 1871 ° C. The sludge, which through the pipe 68 Water to make the slurry sprayable and the nozzle 69 flows, cools it and prevents do. The addition of water in this special one that they melt.

Approach is from about 24.6 to 37.851 with satisfactory. Preparation of a refractory spray

The results have been varied. The approach for 45 according to the present invention, i. i.e. that the a special use is made according to the size of silica soda or other binders beforehand of the furnace and are solved according to its operating conditions, requires very little equipment, vary. because the mixing vessel does not have to be heated. That's why

On the basis of FIG. 1 and 2 is for the better it can be smaller and to the different places of the Understanding the method of the invention will make a 50 oven movable. That is why the transportation Device for its implementation, for example, the sludge from a heated mixing vessel described. Such a device consists of a movable spray device avoided. It a mixing vessel 10, with a high speed one, has been found to work better with the refractory material Mixing apparatus 50, which consists of a drive motor 52, adheres to the furnace surfaces, if one is commercially available a drive shaft 54 and a multiplicity of 55 prepared, previously dissolved solution of silicic acid Pellern 56 and 57 consists. Baking soda, as if one were in place after one

The propellers are arranged in such a way that the inferior process processed solution is diluted on the ground Kessel a strong mixing effect is achieved, is turned. The known methods also collide because the particles are heavy and quickly dissipate - up to 50% of the refractory material during spraying set. The pitch of the propellers is such that 60 from the furnace walls. According to the inventor the boiler a flow in the direction of the arrows dung reprocessed materials bounce 5% or (Fig. 1) is generated. less starting, which of course is a lower loss

A pipe 62, means, runs through the top of the boiler.

which feeds the slurry to the nozzle 69, although the invention is on hand of use

has been described to the upper part 65 for metallurgical furnaces via the valve 74 and the line 72 the boiler is supplied with compressed air. Also emphasizes that she does not operate on metallurgical furnaces the compressed air is restricted with the help of valve 78, but also for other ovens, ζ. Β. Spraying the material. for glass furnaces.

Claims (3)

Patent claims: 1. Method for lining furnace surfaces with a mixture of a sticky silicate solution and refractory particles, characterized in that with the help of under Pressurized water vapor converts the silicate into a sticky solution, which with the refractory particles is mixed into a sprayable suspension. 2. The method according to claim 1, characterized in that the refractory particles are finely divided be introduced into the mixing unit and that the suspension during mixing on the Surfaces is sprayed on. 3. The method according to claim 2, characterized in that the suspension in the mixing unit is under gas pressure and that it is mixed with gas and discharged as a spray mist. 1 sheet of drawings