CN110787738A - A oxidizer that is used for aldehyde silver catalytic oxidation method to produce - Google Patents

Abstract

The invention discloses an invention oxidizer for aldehyde silver catalytic oxidation method production, which comprises a shell pass cylinder, wherein the shell pass cylinder is divided into a catalytic reaction layer and a quenching section from top to bottom; the shell-side cylinder body is provided with two steam outlets, the steam outlets are positioned on the shell-side cylinder body outside the catalytic reaction layer, and the height of a steam-water mixture in the steam outlets is higher than that of the catalytic reaction layer; the shell pass cylinder body is divided into an upper part variable inner diameter part and a lower part with the same inner diameter. The invention solves the problem that the ternary mixed gas is unstable when the silver layer reacts, reduces the pull-out force of the heat exchange tube nest on the tube plate, greatly improves the welding qualification rate and shortens the manufacturing period.

Description

A oxidizer that is used for aldehyde silver catalytic oxidation method to produce

Technical Field

The invention relates to the technical field of chemical equipment, in particular to an oxidizer for catalytic oxidation production of aldehyde silver.

Background

The aldehydes belong to chemical products with wide application, mature production process and sufficient raw material supply, the production process mostly adopts a silver method catalytic oxidation technology, alcohol raw materials and air enter an evaporator to be vaporized to form a raw material mixer, and the raw material mixer enters an absorption tower after being reacted by an oxidizer to complete the oxidation production process flow. With the increasing demand of aldehydes, the oxidation apparatus is continuously improved or newly purchased on the basis of the original oxidation apparatus, and the oxidation apparatus becomes a means for many manufacturers to achieve the purposes of increasing the yield, saving the energy consumption and the like.

Taking a silver-process catalytic oxidation technology as an example, an oxidizer is a core device in a production process, an air, alcohol and steam three-way mixer enters from the top of the oxidizer, furnace gas after reaction of a reaction layer of the catalyst enters a quenching section of the oxidizer to exchange heat with soft water after temperature rise of a heat exchange section of the oxidizer, saturated steam generated after heat exchange enters a steam system for production, reaction gas after temperature reduction of the quenching section enters a heat exchange section of the oxidizer to exchange heat with low-temperature soft water again, and the reaction gas after further temperature reduction is sent to an absorption tower.

The quenching section of the oxidizer adopted by most of the existing manufacturers is of a traditional cylindrical structure, the reaction gas passes through a tube pass, and the water or steam for heat exchange passes through a shell pass. The above-mentioned structure has a problem in that the cylindrical-structured quench zone of the oxidizer generates a small amount of by-product steam, which cannot satisfy its own heat demand, and requires the supply of steam from outside the system, inevitably increasing the production cost of the aldehyde product.

In addition, the tube plate of the heat exchange tube adopted by the existing quick cooling section of the oxidizer is stressed greatly, the quick cooling section of the oxidizer with the existing structure is biased to adopt the tube plate with larger thickness, so that the manufacturing and modification cost of equipment is higher, and if the quick cooling section of the oxidizer adopts the thinner tube plate, the service life of the oxidizer is reduced under the action of larger stress.

Disclosure of Invention

The object of the present invention is to provide an oxidizer for the catalytic oxidation production of silver aldehydes which allows to overcome the above technical problems through structural improvements.

In order to achieve the purpose, the invention provides the following technical scheme:

an oxidizer for catalytic oxidation production of aldehyde silver comprises a shell-side cylinder, wherein the shell-side cylinder is divided into a catalytic reaction layer and a quenching section from top to bottom; the catalytic reaction layer is positioned above the quenching section; the shell-side cylinder body is provided with two steam outlets, the steam outlets are positioned on the shell-side cylinder body outside the catalytic reaction layer, and the height of a steam-water mixture in the steam outlets is higher than that of the catalytic reaction layer; the shell pass cylinder body is divided into an upper part variable inner diameter part and a lower part with the same inner diameter.

Furthermore, a folding structure is arranged at the connecting position of the tube plate and the shell pass cylinder body, and the folding structure and the shell pass cylinder body are in butt welding.

Furthermore, an expansion joint is arranged on the shell pass cylinder.

Furthermore, the shell pass cylinder body positioned below the expansion joint is a cylindrical cylinder body, and the inner diameter of the shell pass cylinder body above the expansion joint is gradually increased from bottom to top.

Further, the heat exchange tube nest is fixed through a tube plate and welded with the inner wall of the shell pass cylinder.

The invention has the beneficial effects that:

(1) the invention realizes the increase of byproduct steam by adopting the shell pass cylinder body with an irregular structure, ensures the smooth proceeding of oxidation reaction by designing the steam outlet, and solves the problem of instability of ternary mixed gas during silver layer reaction.

(2) According to the invention, through changing the connection mode of the tube plate and the shell pass cylinder inner wall, the pull-out force of the heat exchange tube nest on the tube plate is reduced, the welding qualification rate is greatly improved, and the manufacturing period is favorably shortened.

Drawings

The above and other features, properties and advantages of the present invention will become more apparent from the following description of the embodiments with reference to the accompanying drawings in which like reference numerals denote like features throughout the several views, wherein:

FIG. 1 is a schematic diagram of the construction of the oxidizer of the present application.

FIG. 2 is a schematic view of the folded configuration of the tubesheet in the present application.

In the figure: 1. a catalytic reaction layer; 2. a tube sheet; 3. a steam outlet; 4. a shell-side cylinder; 5. an expansion joint; 6. heat exchange tubes; 7. and (5) folding the edge.

Detailed Description

The technical solutions described in the present application are further described below with reference to the accompanying drawings and embodiments. It should be noted that the following paragraphs may refer to terms of orientation including, but not limited to, "upper, lower, left, right, front, rear", etc., which are based on the orientation shown in the drawings corresponding to the specification, and should not be construed as limiting the scope or technical solutions of the present application, but merely as facilitating better understanding of the technical solutions described in the present application by those skilled in the art.

Example 1 referring to fig. 1, an oxidizer for catalytic oxidation production of aldehyde silver comprises a shell-side cylinder 4, wherein the shell-side cylinder 4 is divided into a catalytic reaction layer 1 and a quenching section from top to bottom; the catalytic reaction layer 1 is positioned above the quenching section; a plurality of heat exchange tubes 6 for cooling are arranged in the quenching section, the heat exchange tubes 6 are fixed through a tube plate 2 and are welded with the inner wall of a shell pass cylinder 4, the shell pass cylinder 4 forms an interlayer for coating a catalytic reaction layer outside a catalytic reaction layer 1, two steam outlets 3 are arranged on the shell pass cylinder 4, the steam outlets 3 are positioned on the shell pass cylinder 4 outside the catalytic reaction layer 1, and the height of a steam-water mixture in the steam outlets 3 is higher than that of the catalytic reaction layer 1;

specifically, a folding edge structure 7 is arranged at the connecting position of the tube plate 2 and the shell pass cylinder 4, and the folding edge structure 7 and the shell pass cylinder 4 are in butt welding.

The shell pass cylinder 4 is divided into an upper part with a variable inner diameter part and a lower part with the same inner diameter part. Specifically, an expansion joint 5 is arranged on the shell pass cylinder 4. The shell pass cylinder 4 positioned below the expansion joint 5 is a cylindrical cylinder, and the inner diameter of the shell pass cylinder 4 above the expansion joint is gradually increased from bottom to top.

In the present application, the shell-side cylinder 4 is divided into an upper part with a variable inner diameter and a lower part with the same inner diameter, wherein an expansion joint 5 is used as a separation point of the two parts. Be provided with steam outlet 3 in the barrel that the upper portion becomes the internal diameter, steam outlet 3 is located the side of catalytic reaction layer 1 and is higher than catalytic reaction layer 1, and this just makes steam outlet 3 form sandwich structure in catalytic reaction layer 1's outside, utilizes the steam mixture of 200 ℃ in the steam outlet 3 to heat the oxidation in catalytic reaction layer 1, guarantees that oxidation smoothly goes on. Secondly, the heating surfaces of the steam outlet 3 and the catalytic reaction layer 1 are increased, so that the gasification amount of the steam-water mixture is increased, and the amount of the byproduct steam is increased to 100-120 kg steam/ton aldehyde from the original 30-40 kg steam/ton aldehyde.

In addition, this application is provided with hem structure 7 in the hookup location department of tube sheet 2 and shell side barrel 4, is changed into to adopt butt welding's connected form by traditional right angle welding between hem structure 7 and the shell side barrel 4, has guaranteed the welded qualification rate, has reduced heat transfer tubulation 6 greatly and has pulled off power to tube sheet 2, has also correspondingly reduced the thermal stress that receives in the reaction process.

Under the condition of the structural improvement and the same design parameters, taking an oxidizer with the diameter of 2600mm as an example, the tube plate of the traditional structure can meet the design requirements only by a steel plate with the thickness of 60mm, and the tube plate of the application can be realized only by a steel plate with the thickness of 25mm, so that 1.47 tons of steel can be saved in the manufacturing process of the tube plate 2.

The shell-side cylinder body with an irregular structure is adopted to increase the byproduct steam, the steam outlet is designed to ensure the smooth oxidation reaction, and the problem of instability of ternary mixed gas in silver layer reaction is solved.

It should be noted that the above-mentioned embodiments are only some of the preferred modes for implementing the invention, and not all of them. Obviously, all other embodiments obtained by persons of ordinary skill in the art based on the above-mentioned embodiments of the present invention without any creative effort shall fall within the protection scope of the present invention.

Claims (5)

1. An oxidizer for catalytic oxidation production of aldehyde silver comprises a shell-side cylinder body and is characterized in that the shell-side cylinder body is divided into a catalytic reaction layer and a quenching section from top to bottom; the catalytic reaction layer is positioned above the quenching section; the shell-side cylinder body is provided with two steam outlets, the steam outlets are positioned on the shell-side cylinder body outside the catalytic reaction layer, and the height of a steam-water mixture in the steam outlets is higher than that of the catalytic reaction layer; the shell pass cylinder body is divided into an upper part variable inner diameter part and a lower part with the same inner diameter.

2. The oxidizer of claim 1, wherein a hem structure is provided at the connection position of the tube plate and the shell-side cylinder, and the hem structure and the shell-side cylinder are butt-welded.

3. The oxidizer of claim 1, wherein an expansion joint is disposed on the shell-side cylinder.

4. The oxidizer of claim 3, wherein the shell-side cylinder below the expansion joint is a cylindrical cylinder, and the inner diameter of the shell-side cylinder above the expansion joint increases from bottom to top.

5. The oxidizer of claim 1, wherein the heat exchange tubes are fixed by tube sheets and welded to the inner wall of the shell-side cylinder.

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