RU1837962C - Method for manufacture and reinforcement of catalyst block - Google Patents

Abstract

The invention relates to a method for manufacturing and reinforcing a catalyst block (1) for purifying exhaust gases, in which the spiral block (1) is formed from a strip of corrugated film (2) and a strip of straight film (3). pre-coated with a layer of carrier material and a catalyst layer, which (block) may have an oval or round shape. After the formation of this block, the support (4) is pressed through this block, while the support prevents unwinding of the block and friction of the stripes of films against each other, and in this way a rigid catalyst block (1) that retains its shape is obtained. 1 s P. f-ly. 4 ill.

Description

The invention relates to a method for manufacturing and reinforcing a catalyst block for purification from single gases, in which a spiral block is formed by winding a strip of corrugation | a thin film and a strip of straight cloth located one above the other.

A subject of the invention is a method for recovering and reinforcing catalyst-o. block, a method that is devoid of the lack of ITKOB inherent in previously known dogs. This is achieved in accordance with

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of the invention by winding a strip of my thin film and a strip of corrugated thin film, pre-baked with a layer of carrier material and a layer

catalyst material around a shaft of a certain size so that after removing the shaft, an elongated hole of the desired size remains in the center of the unit. Then this block is pressed into an oval shape, i.e. the cross section of this block must be in the shape of a raster track and the hole in the center of the block is closed. Further, the caliper is pressed or passed under pressure through this block, and this caliper prevents unwinding of the block and friction of the film strips from each other, and in this way a rigid system is obtained that retains its shape.

According to one of the principles of this invention, it is possible to manufacture kata00

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lyser unit by winding a strip of straight film and a strip of corrugated film pre-coated directly on a rounded part so that no elongated hole remains in the center of this part. After that, the caliper is pressed or passed under pressure through this block; this caliper will prevent unwinding of the block and friction of the film strips against each other, and. in this way a rigid system is obtained which retains its shape.

According to another principle of the present invention, two or more calipers are pushed through the block so that the calipers are either parallel to each other or in sequence one after another.

The passage of the calipers through the block can be accomplished either by pushing through or by injection under high pressure. According to one of the principles of the present invention, for a caliper, a hole having a caliper length can be preliminarily obtained by, for example, drilling, and after receiving such a hole, the caliper which is to fill this hole is pressed into it.

The support pushed through the block preferably has a circular, oval, square or rectangular cross-sectional shape. According to the present invention, the support passed through the block has a length of a block diameter (round block) or a length, height of a block (raster track), or its length is preferably 1-10 mm greater than the diameter or height of the block.

The caliper or calipers passing through the block are preferably made of fireproof steel.

If a round block is made by bonding a strip of a straight metal film and a strip of corrugated metal film pre-coated with a layer of carrier material and a catalyst layer, with a central shaft representing a thin rod or a workpiece, a curved s U-shape, consisting from a sheet and around which a round block of the desired size is formed. then this central shaft. used as the axis of rotation remains inside the block. For the winding of the block, one or more holes are made in the central shaft so that after winding the block, the caliper pushes or passes under pressure through this block so that it passes through the hole or holes in the central shaft. In this way, a rigid catalyst block is obtained which retains its shape.

In FIG. 1 shows an end view of the proposed device; in FIG. 2 is a side view of the block,

In FIG. Figure 1 shows the catalyst block 1 obtained by winding a strip of corrugated film 2 and a strip of straight film 3 located one above the other, which (block) is pressed into a raster form after it is wound, after which a support 4 is pressed through this block.

In FIG. Figure 2 shows a round block 1 obtained by winding a strip of straight film 3 and a strip of corrugated film 2, one above the other, and black: which is pressed through a support 4 of a somewhat larger length than the diameter of the block itself.

With respect to the purpose of the present invention, the catalytic unit of the present invention is easy to manufacture, and the caliper effectively prevents unwinding and reciprocal friction in this unit, which is an advantage of this proposal compared to those known in the art. In addition, when the block is pressed into a racetrack, the hole in the center of the block is blocked so that the exhaust gas cannot pass through it without coming into contact with the catalyst ..

Example 1. Direct metal foil and corrugated metal foil were subjected to heat treatment at 800 ° C for 20 hours, 225 g of boehmite were mixed with 385 g of 1.5% acetic acid at room temperature, and the sludge was ground to particle sizes less than 5 microns. The heat-treated metal foil was coated with a layer of this substrate material and dried at a temperature of 120 ° C, followed by calcination for 4 hours at a temperature of 550 ° C. The foil coated with the substrate material was immersed in a PT RH solution, dried and subjected to hydrogen reduction. Then the sheets of foil were laid on top of each other and fixed from one end to the shaft. A block of the desired shape was made around the shaft by winding, after which the shaft was removed. Next, the block was pressed to give it the shape of a racing track and a caliper was passed through the bute, almost in the middle of the axis of this block.

According to the proposed method, foil strips are used which are preliminarily coated with both a support material and a catalyst layer, and thus soldering may not be carried out.

yulga so as to prevent jamming and mutual friction in this unit. This is accomplished by passing; pass through the block.

There are two ways to obtain this; The first way is: in that. that the ends of the corrugated and unbroken foil strips located jpyr above each other are pressed between a pair of winding rods from both ends. A cage-sized block is wound onto a rod in a winding machine and then the rod is given. The result is a block without a tucked hole in the center of the block. Another way is to wind the strips around the central shaft, which is then removed by pulling it out. At that, the native value remains in the center of the block. This | ioe hole is closed by pressing a block in a mold to give it a real or other desired shape. A block receiving field is drilled through it. This hole is usually not too deep, but it is usually such that the caliper is set to the desired position. The caliper or calipers pass through the block using a pneumatic hammer.

The calipers are placed around the edges of the central shaft of the block, and the central shaft remains inside the block, which gives the block excess weight and reduces the narrowing of the cross section of the hole of the catalyst block.

Thus, the distinguishing features of the present invention are absent in the method described in the previously known publication.

There are several ways to achieve the desired result, but what is important in this method. that unwinding of the spool is prevented by skipping - “I, at least one support - block 3. The block can also be made as follows:

EXAMPLE 2 A catalyst block is prepared by applying a firmly adhered gamma alumina coating to an O1 coated Fe-Cr-AI-Y foil coated with crystals. The foil consists of an alloy consisting in weight of; 15% xj ohm, 4% aluminum, 0.5% yttrium, and the rest is iron. The foil is separated from the rotating cylindrical workpiece by applying a cutting tool of durable tungsten carbide to the peripheral surface to continuously separate a thin metal strip from the NF. The foil has an irregular and carefully machined surface, which is preferred for growing dense alumina whiskers.

Before growing whiskers, the foil is subjected to solvent cleaning and annealing for one minute at a temperature of 900 ° C in air. The annealed foil is corrugated by passing it between a pair of drive rolls provided with mating teeth mounted in a zigzag pattern to form a zigzag pattern or a fish-like pattern on the foil.

The oxide whiskers are grown by heating the foil for 24 hours at a temperature of 900 ° C in a circulating atmosphere furnace. The surface covered with whiskers is coated with a gamma alumina coating using an alumina gel primer. Soil gel; digests were prepared by mixing on May 5.0. including colloidal monohydrate of al-omini alpha-oxide with 95 parts of a deionized Veda. The resulting physical mixture of alumina particles in water is stabilized by the addition of concentrated nitric acid to lower the pH below 2.0. Typically, approximately 5 parts of nitric acid is sufficient.

A lower alumina ace / yuga gel is prepared for use as a binder for applying gamma alumina powder. The binder gel contains May 3.0. h, colloidal alpha alumina monohydrate in 97 parts of water and is also stabilized with nitric acid to a pH below 2.0. Gamma alumina powder has a porosity of more than about 1 cm3 pore per gram and about 70% of the particles have a size of less than 74 microns and more than 44 microns. The coating material is obtained by uniform mixing on May 27th. including gamma alumina particles with approximately 100 parts of gel. Thus, alumina in the coating material is about 90 wt.% Gamma alumina and 10 wt.% Gel based alumina.

The surface of the foil is spray-coated using a gravity-fed air aspirator. Primer coating from the said alumina gel (alumogel) - first sprayed onto the surface covered with whiskers as thick as possible, without pumping or dripping. Before the primer dries, a first layer of gel containing particles is applied by spraying. Double layer

the film is dried in hot air until it turns white, the dried film has a thickness of approximately 15 μm, two to five additional: coatings of a material containing particles are similarly sprayed and air dried to obtain a general coating gamma-alumina with a thickness of 40-50 microns. The air-dried multilayer coating is calcined for four hours at 550 ° C in air.

The finished gamma-alumina coating is impregnated with a noble metal catalyst. A solution containing the catalyst is prepared by dissolving predetermined amounts of tetraamineplatinum chloride (} tetraamine palladium (II) chloride and pentaaminrodium chloride OI) in water. The solution is applied evenly to the foil by passing the unwound foil between the sponge pads, onto which the noble metal solution is dosed at a given speed in order to provide the required amount of metal per structure. The wet coating is dried with a hot air blower and calcined for four hours at 550 ° C in an atmosphere consisting of 4 vol.%, Hydrogen and 96% nitrogen. Calcination destroys complex amine salts and restores noble metals to their elemental and catalytically active states.

After coating the straight foil tape and the corrugated foil tape, they are placed on top of one another and attached to the shaft at one end. After wrapping the foil over the block, the shaft is removed. Another way to obtain a spiral block is to lay the foil on top of one another and then squeeze the ends of the foil between a pair of winding rods from both edges of the foil. After folding the spiral, the required size of the bars is removed; The size of the block depends on the model of the cart that is intended for use.

The caliper is passed through the block by pressing or shooting in any known manner. If necessary, the hole can be drilled in advance through the block, and the caliper is placed in this hole. To prevent unwinding of the foil, a caliper can best

have a length slightly larger than the diameter or height of the block.

An advantage in coating the foil before winding is that if the pieces of foil are first wound one around the other and then coated, then the coating material accumulates in the cavities formed by the points of contact

pieces of foil, which reduces the cross section of the channels in the block and increases the back pressure. The block of the present invention has less back pressure and thus works better because the pieces of foil are coated in advance and thus no accumulation of coating material occurs and the cross section of the channels is larger. Since the caliper passes through the block, no unwinding takes place.

In the known patent (see Figs. 3 and 4), the calipers 5 are welded to both ends of the central shaft 4. In this method, the central shaft remaining inside the block,

gives the unit additional weight, and the central shaft with its end supports reduces the open (live) cross section of the unit. The method is also more difficult to implement than the proposed method.

Claims (2)

1. A method of manufacturing and reinforcing a catalyst block for exhaust gas purification, comprising forming a spiral block from a corrugated film tape and a straight film tape, previously coated with a layer of carrier material - alumina, and a catalytic layer containing platinum group metals by winding the tapes onto the shaft, introducing at least one support passing through the block, characterized in that, in order to simplify the method, the latter is removed after winding the tapes onto the shaft, the block is pressed into an oval shape and the introduction of the support is carried out by forcing it through the block or by drilling a hole and placing it in him a caliper. 2. The method according to claim 1, characterized in that a caliper is used passing through the block, having a length of 1-10 mm greater than the diameter of the block. s r pu.1 / x / / / / h