JPS62501411A - collection pack - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] City collection Basokuze≠≠Nakagami The present invention is particularly useful for catalysis and alloying of rhodium, typically in nitric acid production plants. oxidation consisting of one or more gauze woven from wire containing Nitrogen oxide is first produced by passing a mixture of ammonia and air through a catalyst at high temperature. This is a normal method. When used, platinum and, to a lesser extent, rhodium itself is converted into oxides, and these oxides are volatile at plant operating temperatures; Therefore, the loss of platinum and rhodium entrained in the nitrogen oxide stream is reduced to an acceptable level. In order to reduce It has been developed to enter Such bucks typically each have a catch It consists of an interleaved gauze woven from texture and support material. appropriate power A commonly used capture material is an alloy of palladium and gold, e.g. 20% gold. - palladium; a suitable support material is, for example, Megapyr 2 (registered trademark). It is an oxidation-resistant stainless steel such as

A cross-sectional view of a typical ammonia oxidation reactor is shown in attached Figure X. Figure X The catalytic platinum-rhodium mesh is indicated by 1 (reference numeral) and is inserted between on a collection bag 2 with a stainless steel support and a gold/palladium capture fine mesh. Supported. The entire catalyst/collection gauze assembly includes a gasket between the four reactor flanges. 3 are tightened together. A strong support bar 5 is provided across the reactor surface. ing. Figure 7 of the accompanying drawings details an alternative means of assembling and supporting the collection gauze bank. hot water The fine mesh in this example has a diameter slightly smaller than the diameter of the reactor so that It has an expansion space 6 and is supported on a strong support bar, e.g. Supported by a coarse braid machined from “Iconel”(TM) steel There is. Additionally, in this arrangement, the top stainless steel fine mesh screen captures the remaining and the supporting gauze, and at position 8 said remaining gauze. By folding it downward beyond the outer periphery of the bag, the entire bag can be folded into one unit. It can be treated as a knit. This means that the capture substance has its capture activity paLgn ) may be retained for twice or more than the period known as In use, the captured material is reacted to renew the catalytic gauze at the end of the campaign. When disassembling the reactor or if it is necessary to disassemble the reactor for any other reason, undergoes embrittlement leading to damage to the fine mesh during early migration to the The reactor diameter may be in the range of 3 m or more in case it needs to be disposed of at some point in time. In low-pressure or medium-pressure oxidation plants where banks are handling causes damage and embrittlement. Furthermore, of course, A collection gauze bag suitable for such large diameter reactors can be safely stored and transported. and are generally considered to be particularly heavy and voluminous products for handling.

It is therefore an object of the present invention to provide a substantially rigid, easy to store and transport, and capture Catalytic reactors such as ammonia oxidation reactors without material damage A collection bag that can be easily removed from the catalytic reactor and replaced with the catalytic reactor. The objective is to provide a

We assume that the collection back consists of multiple back segments, e.g. The components are placed in contact with each other within the reactor, and together they act as a catalyst. It was found that the fine mesh acts as a collection bag that spreads over substantially the entire surface area. .

According to one aspect of the invention, we have provided a collection system suitable for use in an ammonia oxidation reactor. a back segment, the segment comprising one or more separate collection pack segments; The elements are placed end-to-end in plane contact with each other to form a predetermined geometric shape. and capturing said segment. support strips interposed between one or more wire bands formed from the material We propose a collection bank segment that is made up of mesh segments.

According to a second aspect of the invention we provide one or more of the desired shapes constructed from the capture material. Insert a wire band of at least 100 mm in length between the supporting gauze segments of the desired shape and and securing said segments and said or each band together. Provides a method for creating segments.

The present invention also preferably has a predetermined shape according to the above-mentioned first or second aspect of the present invention. involves creating from multiple segments that are of regular shape.

The wire band consists of structured wires or randomly oriented wires. Both can be compressed. The term knitted wire means a wire interface or a twisted loop.

If the pad is in the form of a knitted wire, it can be formed as a continuous tube. , which can be longitudinally incised and expanded to form a single knitted layer. Kaka The metal weight of the single knitted layer is 50-1500 g/m, preferably 150-1 It can be 300 g/%.

The collection bag is intended to be used in a catalytic reactor such as an ammonia oxidation reactor. In some cases, the collection bag is made of oxidation-resistant stainless steel, such as Megap at least two gauze segments made of a support material such as yr2, and the or an alloy of, for example, palladium and gold, interposed between each two adjacent support materials; one or more wires made of capture material, such as 20% gold-palladium; Consists of pads. In this case, other capture substances, especially less robust materials or It goes without saying that it is also possible to use materials that become less robust with use. Nor.

- If more capture material bands are used, each pad has a different fine mesh Preferably, the pores are of different porosity (νoid solution). this is , the flow section(s) of the collection bag absorbs a relatively large amount of platinum and rhodium. In order to adhere to the skin, the layers need to be made more durable, and these will swell even more during use. This is because it is easy to do. In addition, the downstream part of the collection bag (single or plural) is the actual back pressure. Passing through the upstream part (number of faces or faces) of the collection bag avoiding qualitative increase1. Ga after vinegar? In order to more effectively collect platinum and rhodium that still remain in Jt. Therefore, the porosity should be low.

The diameter of the wire should vary from 0.05 mm to 0.4 mrn. preferred range The range is 0.06 to 0.25 in relation to the metal weight optimized according to the bank position. It is mm.

The production, transportation and storage of collection back segments according to the invention involves ammonia oxidation. Traditional collection bags of banded wire spread over the entire surface of the reactor, esp. Compress multiple pads together over a large area and support them between fine mesh Conventional ammonia oxidation reaction with more than one wire pad that needs to be fixed It is easier to manufacture, transport and store the collection bag for the reactor. wire band collection bar Bags are relatively inflexible (unlike fine mesh collection bags) and suitable for transportation and storage. It is not possible to roll it up into a tubular shape by using the provides unique and practical benefits.

If wires of different gauges are used for adjacent pads, the upstream pad Typically consists of wires with a diameter of 150-250 microns, and downstream The band typically consists of a wire with a diameter of 50-100 microns. During ~ The bands in between typically consist of wires with a diameter of 100-150 microns. can be done. The thickness of each pad and total collection bag is determined by the specific ammonia oxide plastic. depending on the operating pressure of the component and other balata.

According to the invention, the six back segments can have a sector shape, for example a semicircle or a quadrilateral. one or more separate bank segments, which may have the shape of a semicircle; (This other segment or segments may be the same as the first segment or may or may not have a similar shape) any other shape that gives a given geometric shape, e.g. a regular geometric shape. can have.

It is usually preferred that the regular shape described above is circular, but e.g. rectangular, circular Alternatively, it may be a polygon, for example a hexagon.

The invention also includes a method of creating a collection backsegment.

For example, collection bank segments according to the present invention can be made of any desired material and shape. Assemble or stack the parts in the required order and secure them together to form the bag. do. The fixation may be, for example, one or more edges of the outermost support gauze segment. The section is folded in at the edge of the rope, thus in this case at least one fine mesh segment. Increase the size of the remaining segments to fit the appropriate edges needed for folding. ), or by cutting, riveting, or tying with wire, etc. It can be implemented by

The individual bank segments according to the invention are in plane abutting relation to each other. can be arranged in a circular or other regular shape in the catalytic reactor However, we consider that for many purposes C7 the segment itself is for transportation and storage. The entire collection bag can be folded to estimate the shape and area of its individual segments. It has also been found that it is advantageous to hinge the segments so that another Methods include hinged or otherwise connecting individual segments in a reactor. They can also be temporarily fixed to each other.

For placement in a catalytic reactor, e.g. folded banks can be placed on support bars or The folded bag can be placed on top of other support means with the outer edge of the bag Place it adjacent to the rhododendron, then unfold the back and separate The collection back segments meet in a plane (the expansion gap on the outer periphery and the adjacent Realize the cross-sectional area of the reactor (excluding small gaps between hinge ends such as bank segments). Be positioned to cover qualitatively. Aspects of the present invention are illustrated in the accompanying drawings. An exemplary explanation will be given with reference to FIG. 3. In these drawings, Figure 1 is a quadrant-shaped A perspective view of the collecting back segment is shown, partially cut away to show the cross-section of the bank. Figures 2A to 2E show how to connect the four quadrants shown in Figure 1 with hinges. Figures 3A-3J show how the collection back segment can be folded. This section shows various ways of assembling to form collection bags with regular geometric shapes. Referring to Figure 1, the collection back segment 10 shows a quadrant shape. outermost Supporting details m11, 12 and three wire pads 13.14 fixed between them and 15, and these wire pads are made of a material such as palladium gold alloy. The wire is made of a woven and compressed capture material. Pad 13 is the The pad is also constructed from heavy gauge (200μ) wire and lightly compressed, then pad 1 4 is constructed from lighter gauge (125μ) wire and is relatively highly compressed. It will be done.

Pad 15 is constructed from the lightest gauge (75μ) wire and is the most highly compressed. be done. The band and support gauze are secured together with staples 16 and back segmented. form a point. Pad 13 is the upstream pad when placed next to the catalyst gauze in the reactor. It is good.

As shown in Figure 1, one side hinges the four collecting back segments 1-. The method is as shown in Figures 2A-2E.

FIG. 2A shows mutually adjacent ends of the segments S1 and SS, Sl and S4 . Four collecting back segments Sl, S2 . hinged at SS and S4. S 3 and S4 are shown. The hinge connection is designated SS. Figure 2B is the first (i.e. segments S1 and SS are folded together into segments S3 and S4) Figure 2C shows the second and third folds (i.e. Fold segments S3 and SS onto segments S4 and Sl, respectively. ). Figure 2D shows the resulting folded collection back segment; Figure 2E is an unfolded bag that can be used as a collection bag to be placed in a catalytic reactor, for example. Showing the back segment. In some cases, segments S2 and SS are e.g. SS (original hinge connection omitted for clarity) as shown in Figure 2E. ) can be woven to hold them together.

One back segment according to the invention can be made by any conventional method such as knitting. By using a hoop, or by a hoop and a rondo. can be hingedly connected to another back segment. hoop or other Needless to say, the material used to create the hinge connection means, as well as the purpose of the collection bag, Even if it is used in a and should preferably be suitably flexible to facilitate folding, e.g. It must not interfere with the catalyst mesh in contact with it. Hinge connection in some cases The continuation can be done in the field, for example by inserting and removing rondos in a series of hoops. It can be connected or disconnected.

In particular, the present invention has been described with reference to a collection back segment that is shaped like a quadrant. However, the present invention provides a bank segment consisting of a plurality of segments, and one or more segments. is a laminate obtained by stacking another, with the individual segments in a fixed relationship to each other. Provides an assembled back segment by allowing it to be held in I hope you understand that. Another embodiment of the invention is shown in the accompanying FIG. allows the back segments to be placed in a plane-adjacent relation to each other. A method is shown. The individual bank segments in Figure 3 may, in some cases, be adjacent to each other. Collection bags with regular geometric shapes hingedly connected to adjoining segments give. In some cases, the A6 bank segment in Figure 3 may be an adjacent segment. can be hingedly connected to.

The collection bag can be several meters in diameter or less, and can be segmented as described above. The provision of optional hinge connections for transport from the manufacturer to the site, e.g. a nitric acid plant, Saves a considerable amount of space during transport. In addition, if the cost of transportation consists of The present invention significantly reduces this girth.

A collection bag consisting of segments according to the invention can be easily installed in a plant. individual bank segments without damaging the captured material. by removing or folding the segment if hinged. It can also be easily removed. The removed bag can be easily handled. It can be stored reliably during plant maintenance, etc., and it can also be used for refining and platinum recovery. may be transported for the purpose of collection.

FIG.X. (Jong Dongwang J) F[G, Yc 沁1涙i) , Hoko U, Chigu 2 explanation- 1---=, ;1 Denless Stino/Au/Pd international search report ANNEX To'A-J: INTERNATIONAL SE entering RC'd RΣ? ORT vNINTERNATIONAL APPLICATION No, PCT/GB 84100428 (SA-8595) CB-A-2 14104212/12/84 Ncie

Claims (17)

[Claims] 1. A collection pack segment suitable for use in an ammonia oxidation reactor, comprising: , the segment is mutually end-to-end in a plane with one or more other collection pack segments. A plurality of collection packs having a predetermined geometric shape are arranged such that their ends touch each other. wherein the segments are formed from captured material; consisting of supporting gauze segments interposed with one or more wire pads. collection pack segment. 2. the supporting gauze segments and the or each wire pad are at least assembled; having substantially the same shape and area when placed together and fixed in superimposed relation to each other; 2. A collection pack segment according to claim 1, wherein the collection pack segment is held in place. 3. 3. The method of claim 2, wherein said supporting material is made of oxidation-resistant stainless steel. Collection pack segment. 4. Claim 2, wherein the capture material is an alloy of gold and palladium. Collection pack segment. 5. Said claim wherein said segment and said or each wire pad are in the shape of a circular sector. Collection pack segments listed in any section of the range. 6. 6. The collection pack segment according to claim 5, wherein the fan shape is semicircular. 7. 6. A collection pack segment according to claim 5, wherein the fan shape is a quadrant. 8. Wire pads are organized wires or randomly oriented wires A collection pack segment according to any of the preceding claims. 9. The collecting pack segment according to claim 8, wherein the wire is compressed. nt. 10. Place one or more wire pads of the desired shape made of capture material. Insert between support gauze segments of key shape, and the segments and the or A method of making collection pack segments consisting of fixing each pad together. 11. The outermost support gauze segment is larger in size than the remaining segments. It is constructed so that its edges are bent and fixed at the end of the laminated assembly. Scope of Claim 10. The method according to item 10. 12. one or more having a predetermined geometric shape and formed from capture material; collection pack segments consisting of supporting gauze segments bound together with wire pads of Two or more members are arranged in a mutually planar, end-to-end relationship. Collection pack consisting of. 13. the pack segment and the or each pad have substantially the same shape and area; The collection pack according to claim 12. 14. at least two of the pack segments have different shapes and areas A collection pack according to claim 12. 15. Claim 12, wherein at least two adjacent segments are hinged. , 13 or 14. 16. A collection constructed and arranged as described and illustrated with reference to Figure 1 of the drawings. pack segment. 17. The structure is as described and illustrated with reference to either FIGS. 2 or 3 of the drawings. The collection pack is constructed and placed.