Oxidation reactor equipment for silver-method formaldehyde production

Abstract

The utility model discloses oxidation reactor equipment for producing formaldehyde by a silver method, which comprises an outer cylinder, a water inlet pipe, a water outlet pipe, a liquid level meter, a desalted water inlet, a liquid level meter lower opening and a drain outlet, and a water outlet pipe, wherein the outer cylinder is provided with a raw material inlet, a steam ascending pipe outlet, a liquid level meter upper opening and a desalted water outlet; an outer cylinder expansion ring is arranged on the outer cylinder; a lower pipe section of the circulating pipe is arranged between the outer cylinder expansion ring and the drain outlet; a circulating pipe upper pipe section is arranged between the outer cylinder expansion ring and the liquid level meter lower opening, and the circulating pipe upper pipe section and the circulating pipe lower pipe section are connected through a steel wire hose; a product outlet is formed in the bottom end of the outer barrel; an inner barrel, an upper tube plate, a heat exchange tube nest and a lower tube plate of the heat exchange tube nest are arranged between the raw material inlet and the product outlet; the lower tube plate and the upper tube plate of the heat exchange tube nest are connected through the heat exchange tube nest; the upper tube plate is connected with the inner cylinder, and the anti-seismic flexible thin tube plate expansion ring combination is arranged on the inner cylinder; a catalyst chamber is arranged in the inner cylinder, an igniter is arranged between the catalyst chamber and the upper tube plate, and a silver catalyst layer is arranged on the upper tube plate; and the stress cracking phenomenon caused by high temperature difference is overcome.

Description

Technical Field

[0001] The utility model relates to the technical field of silver method formaldehyde reactors, and particularly relates to an oxidation reactor device for silver method formaldehyde production. Background Technique

[0002] The existing formaldehyde production uses refined methanol as raw material and adopts the electrolytic silver method production process; 99%-99.9% of refined methanol evaporates in the methanol evaporator, then mixes with a certain proportion of air, adds ingredient steam, is heated to 100°C - 130°C through a heater, and then enters the formaldehyde oxidation reactor after passing through a filter and a flame arrester. In the reactor, after the four-component gas of methanol, air, water vapor, and tail gas is ignited and heated up by an electric furnace, under the action of a silver catalyst, methanol undergoes oxidation and dehydrogenation reactions to generate high-temperature formaldehyde gas, and then the high-temperature formaldehyde gas is cooled to below 150 - 200°C and absorbed by an absorption tower to obtain a formaldehyde solution;

[0003] The formaldehyde oxidizer is the core equipment for silver method formaldehyde production. In the formaldehyde oxidizer, raw material methanol and air undergo dehydrogenation oxidation reactions under the action of a silver catalyst to produce formaldehyde. Due to many side reactions under high-temperature conditions, it is necessary to quickly pass through the catalyst bed layer in the reactor and quickly remove a large amount of heat. The function of the formaldehyde oxidizer is to provide a catalytic catalyst space for the raw materials and a device for quickly removing reaction heat. The formaldehyde oxidizer directly affects the consumption of raw materials and the production cost of formaldehyde, and affects the economic benefits of formaldehyde production. It is the core life of the silver method formaldehyde production device.

[0004] Currently, the formaldehyde oxidizers on the market are prone to stress cracking due to high temperature differences and have low heat dissipation efficiency. Content of the Utility Model

[0005] The technical problem to be solved by the utility model is to provide an oxidation reactor device for silver method formaldehyde production to solve the technical problems that the formaldehyde oxidizer in the prior art is prone to stress cracking due to high temperature differences and has low heat dissipation efficiency.

[0006] To achieve the above object, the utility model provides an oxidation reactor device for silver method formaldehyde production, comprising: an outer cylinder body, a raw material inlet and a steam riser outlet are arranged at the upper end of the outer cylinder body, and a liquid level gauge upper port, a desalted water inlet, a liquid level gauge lower port and a blowdown port are sequentially arranged on one side of the outer cylinder body from top to bottom; an outer cylinder body expansion ring is arranged between the liquid level gauge lower port and the blowdown port; a lower pipe section of a circulation pipe is arranged between the outer cylinder body expansion ring and the blowdown port; an upper pipe section of the circulation pipe is arranged between the outer cylinder body expansion ring and the liquid level gauge lower port, and the upper pipe section of the circulation pipe and the lower pipe section of the circulation pipe are connected by a wire hose; a product outlet is arranged at the bottom end of the outer cylinder body, and an inner cylinder body, an upper tube sheet, heat exchange tubes and a lower tube sheet of the heat exchange tubes are sequentially arranged from top to bottom between the raw material inlet and the product outlet; the lower tube sheet of the heat exchange tubes and the upper tube sheet are connected by the heat exchange tubes; the upper tube sheet is connected to the inner cylinder body, and an anti-seismic flexible thin tube sheet expansion ring assembly is arranged on the inner cylinder body, and the anti-seismic flexible thin tube sheet expansion ring assembly includes left and right C-shaped anti-seismic flexible thin tube sheet expansion rings and upper and lower C-shaped anti-seismic flexible expansion rings; a catalyst chamber is arranged in the inner cylinder body, an igniter is arranged between the oxidation chamber and the upper tube sheet, and a silver catalyst layer is arranged on one side of the upper tube sheet close to the igniter.

[0007] Further, adjacent heat exchange tubes are arranged in an equilateral triangle arrangement.

[0008] Further, the inner cylinder body anti-seismic flexible thin tube sheet expansion ring assembly includes left and right C-shaped anti-seismic flexible thin tube sheet expansion rings and upper and lower C-shaped anti-seismic flexible expansion rings.

[0009] Further, a demister is arranged in the steam riser outlet, and the demister is fixedly connected to the inner wall of the steam riser outlet.

[0010] Further, the outer cylinder body expansion ring is a C-shaped expansion ring.

[0011] Further, the upper tube sheet is of a concave structure.

[0012] Further, a sight glass is arranged on the outer cylinder body.

[0013] Further, a bracket is arranged on the outer cylinder body.

[0014] Further, the wire hose is connected to the upper pipe section and the lower pipe section of the circulation pipe through a set of upper and lower flanges.

[0015] Further, the material of the oxidation reactor device for silver method formaldehyde production is austenitic stainless steel.

[0016] Compared with the prior art, the utility model has the following beneficial effects: A device for an oxidation reactor used in the production of silver method formaldehyde according to the utility model. By setting the anti-seismic flexible thin tube plate expansion ring combination of the inner cylinder, the expansion ring of the outer cylinder, and the heat exchange tubes, the stress cracking phenomenon caused by high temperature difference is well overcome, and the heat dissipation efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural view of the utility model;

[0018] Figure 2 is a schematic structural view of the upper tube plate;

[0019] Figure 3 is a schematic structural view of the anti-seismic flexible thin tube plate expansion ring combination of the inner cylinder;

[0020] Figure 4 is a schematic structural view of the expansion ring of the outer cylinder;

[0021] Figure 5 is an enlarged view of area A;

[0022] Description of the reference numerals in the drawings: 1 - outer cylinder, 2 - raw material inlet, 3 - steam rising pipe outlet, 4 - upper port of the liquid level gauge, 5 - inlet of desalted water, 6 - lower port of the liquid level gauge, 7 - sewage outlet, 8 - expansion ring of the outer cylinder, 9 - lower pipe section of the circulation pipe, 10 - upper pipe section of the circulation pipe, 11 - steel wire hose, 12 - product outlet, 13 - upper tube plate, 14 - heat exchange tubes, 15 - lower tube plate of the heat exchange tubes, 16 - inner cylinder, 17 - anti-seismic flexible thin tube plate expansion ring combination, 18 - upper and lower C-shaped anti-seismic flexible expansion rings, 19 - left and right C-shaped anti-seismic flexible thin tube plate expansion rings, 20 - sight glass, 21 - support, 22 - catalyst chamber, 23 - igniter, 24 - silver catalyst layer, 30 - demister. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The following further describes the specific embodiments of the utility model with reference to the drawings. It should be noted here that the description of these embodiments is for helping to understand the utility model, but does not constitute a limitation to the utility model. In addition, the technical features involved in the various embodiments of the utility model described below can be combined with each other as long as they do not conflict with each other.

[0024] Please refer to Figures 1-5, a preferred embodiment of the present utility model provides an oxidation reactor device for silver-based formaldehyde production, comprising: an outer cylinder body 1, a raw material inlet 2 and a steam riser outlet 3 are arranged at the upper end of the outer cylinder body 1, and a liquid level gauge upper port 4, a desalted water inlet 5, a liquid level gauge lower port 6 and a blowdown port 7 are arranged on one side of the outer cylinder body 1 in sequence from top to bottom; an outer cylinder expansion ring 8 is arranged between the liquid level gauge lower port 6 and the blowdown port 7, which can solve the problem of thermal expansion and contraction of the outer cylinder body, thereby protecting the outer cylinder body 1. Therefore, the fatigue and scrapping rate of the oxidation reactor cylinder material are greatly reduced, and the service life and use cycle of the oxidizer are greatly improved; a circulating pipe lower pipe section 9 is arranged between the outer cylinder expansion ring 8 and the blowdown port 7; a circulating pipe upper pipe section 10 is arranged between the outer cylinder expansion ring 8 and the liquid level gauge lower port 6, and the circulating pipe upper pipe section 10 and the circulating pipe lower pipe section 9 are connected by a wire hose 11, which can make the water in the oxidizer circulate by itself; a product outlet 12 is arranged at the bottom end of the outer cylinder body 1, and an inner cylinder body 16, an upper tube sheet 13, heat exchange tubes 14 and a heat exchange tube lower tube sheet 15 are arranged in sequence from top to bottom between the raw material inlet 2 and the product outlet 12. The upper tube sheet 13 is of a concave structure, and the concave tube sheet form of the upper tube sheet 13 is similar to that of the bottom of a pot, so as to reduce the resistance to steam generation, make the heat transfer more smooth, and reduce the fatigue of the tube sheet material of the upper tube sheet 13 and the aging of high-temperature materials; the heat exchange tube lower tube sheet 15 and the upper tube sheet 13 are connected by the heat exchange tubes 14; the upper tube sheet 13 is connected to the inner cylinder body 16, and an anti-seismic flexible thin tube sheet expansion ring combination 17 is arranged on the inner cylinder body 16; a catalyst chamber 22 is arranged in the inner cylinder body 16, an igniter 23 is arranged between the catalyst chamber 22 and the upper tube sheet 13, and a silver catalyst layer 24 is arranged on one side of the upper tube sheet 13 close to the igniter 23. The oxidation chamber 22 is located at the upper end of the oxidation reactor upper tube sheet 13, and below the catalyst chamber 22 is provided with a silver catalyst layer 24 and an igniter 23 connected to the oxidation reactor upper tube sheet 13.

[0025] The device comprises an oxidation reaction section and a combined section of gas cooling and waste heat recovery. The oxidation reaction section includes an igniter 23, a silver catalyst layer 24, a catalyst chamber 22, an outer cylinder body 1, heat exchange tubes 14 connected to the inner cylinder body 16, an upper tube sheet 13 connected to the heat exchange tubes 14 and the inner cylinder body 16 of the oxidizer, and a steam riser outlet 3 located on the outer cylinder body 1. Among them, an anti-seismic flexible thin tube sheet expansion ring combination 17 is arranged on the oxidation inner cylinder body 16 for thermal expansion and contraction protection. The heat exchange tubes 14 and the upper tube sheet 13 in the outer cylinder body 1 and the heat exchange tube lower tube sheet 15 are cooled by desalted water to prevent the austenitic stainless steel materials of the heat exchange tubes 14 and the upper tube sheet 13 and the heat exchange tube lower tube sheet 15 from significantly decreasing in strength, plasticity and oxidation resistance at high temperatures.

[0026] Working principle of the utility model: The quaternary mixed gas refers to air, methanol gas, steam and tail gas; it enters the catalyst chamber 22 from the raw material inlet 2 of the high-temperature medium of the quaternary mixed gas, passes through the igniter 23 and reaches the silver catalyst layer 24 to undergo an oxidative dehydrogenation reaction to generate formaldehyde gas. The formaldehyde passes through the heat exchange tubes 14 and then enters the absorption system through the formaldehyde product outlet 12. The upper and lower C-shaped seismic flexible expansion rings 18 of the inner cylinder 16, the left and right C-shaped seismic flexible thin tube sheet expansion rings 19 of the inner cylinder 16 and the upper tube sheet 13 are combined, enabling the upper tube sheet 13 to have sufficient elongation space, well overcoming the stress cracking phenomenon caused by high temperature differences, solving the stress cracking phenomenon and corrosion problem of the high-temperature formaldehyde gas heat exchange in the oxidizer that have long puzzled technicians. The two ends of the heat exchange tubes 14 are welded to the upper tube sheet 13 and the flat heat exchange tube lower tube sheet 15, having sufficient stretching and expansion space, well overcoming the stress cracking phenomenon caused by high temperature differences, and solving the stress cracking phenomenon and stress corrosion phenomenon in the heat exchange section of the oxidizer, problems such as tube cracking and tube sheet cracking.

[0027] Preferably, the adjacent heat exchange tubes 14 are arranged in an equilateral triangle pattern. The number of heat exchange tubes 14 is related to the size of the equipment, and the tube spacing is arranged in an equilateral triangle pattern.

[0028] Preferably, the left and right C-shaped seismic flexible thin tube sheet expansion rings 19 and the upper and lower C-shaped seismic flexible expansion rings 18, and the upper and lower C-shaped expansion rings 18 of the inner cylinder and the left and right C-shaped expansion rings 19 of the inner cylinder are combined together, mainly reducing the expansion and contraction flexibility of the heat exchange tubes 14 and the upper tube sheet 13. For example, it acts on the upper and lower C-shaped expansion rings 18 of the inner cylinder, which are the force-bearing components for up and down expansion and contraction, and acts on the left and right C-shaped seismic flexible thin tube sheet expansion rings 19 of the inner cylinder, which are the force-bearing components for left and right expansion and contraction.

[0029] Preferably, a demister 30 is arranged inside the steam riser outlet 3, and the demister 30 is fixedly connected to the steam riser outlet 3.

[0030] Preferably, the outer cylinder expansion ring 8 is a C-shaped expansion ring, which can solve the thermal expansion and contraction of the outer cylinder 1, thereby protecting the outer cylinder 1. Therefore, the fatigue and scrapping rate of the oxidizer cylinder material are greatly reduced, and the service life and usage period of the oxidizer are greatly improved.

[0031] Preferably, a sight glass 20 is arranged on the outer cylinder 1, which is a window for observing the internal catalyst situation.

[0032] Preferably, a bracket 21 is arranged on the outer cylinder 1 for fixing the device.

[0033] Preferably, the steel wire hose 11 is connected to the upper pipe section 10 and the lower pipe section 9 of the circulation pipe through a set of flanges at the upper and lower parts respectively. The lower pipe section 9 of the circulation pipe and the steel wire hose 11 are connected to the upper pipe section 10 of the circulation pipe to form an external circulation system, and are combined with the outer cylinder expansion ring 8 to form an expansion and telescopic assembly. Therefore, the fatigue and wear rate of the oxidizer cylinder material are greatly reduced, thereby extending the service life of the oxidizer.

[0034] Preferably, the material of the equipment is austenitic stainless steel, mainly using austenitic stainless steels such as S31603, S30408, S32168, 310S, etc.

[0035] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects: By setting the anti-seismic flexible thin tube sheet expansion ring combination 17, the outer cylinder expansion ring 8 and the heat exchange tubes 14, the device effectively overcomes the stress cracking phenomenon caused by high temperature differences and improves the heat dissipation efficiency. For the method of using conventional measures to set expansion rings to reduce the damage of temperature difference stress to shell-and-tube heat exchangers, there are limitations. The application of prestress technology to double tube sheet heat exchangers is proposed. Using the heat exchange tubes as the pre-tightening unit, the structure of the double tube sheet heat exchanger is analyzed by applying different amounts of deformation, and at the same time, appropriate amounts of deformation are studied and compared. The temperature difference stress of the overall structure is effectively reduced, the peaks of stress and strain are reduced, and the damage of the temperature difference stress to the tube sheet heat exchanger is prevented. It effectively overcomes the stress cracking phenomenon caused by high temperature differences, solves the problems of stress cracking and stress corrosion of the oxidizer tubes and tube sheets that have long troubled technicians and equipment manufacturers, and thus finds a more reasonable method for the design and manufacturing of double tube sheet heat exchangers, improving the working life of the heat exchanger.

[0036] The above describes the embodiments of the present invention in detail with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, without departing from the principles and spirit of the present invention, various changes, modifications, substitutions, and variations to these embodiments still fall within the protection scope of the present invention.

Claims

1. An oxidation reactor device for use in silver-process formaldehyde production, characterized in that, Comprising: An outer cylinder body (1), at the upper end of the outer cylinder body (1), there are provided a raw material inlet (2) and a steam riser outlet (3), on one side of the outer cylinder body (1), from top to bottom in sequence, there are provided a liquid level gauge upper opening (4), a desalted water inlet (5), a liquid level gauge lower opening (6) and a blowdown port (7); between the liquid level gauge lower opening (6) and the blowdown port (7), there is provided an outer cylinder body expansion ring (8); between the outer cylinder body expansion ring (8) and the blowdown port (7), there is provided a lower pipe section of a circulation pipe (9); between the outer cylinder body expansion ring (8) and the liquid level gauge lower opening (6), there is provided an upper pipe section of a circulation pipe (10), and the upper pipe section of the circulation pipe (10) and the lower pipe section of the circulation pipe (9) are connected by a wire hose (11); at the bottom end of the outer cylinder body (1), there is provided a product outlet (12), between the raw material inlet (2) and the product outlet (12), from top to bottom in sequence, there are provided an inner cylinder body (16), an upper tube sheet (13), heat exchange tubes (14) and a lower tube sheet of heat exchange tubes (15); the lower tube sheet of heat exchange tubes (15) and the upper tube sheet (13) are connected by the heat exchange tubes (14); the upper tube sheet (13) is connected to the inner cylinder body (16), on the inner cylinder body (16), there is provided an anti-seismic flexible thin tube sheet expansion ring assembly (17), in the inner cylinder body (16), there is provided a catalyst chamber (22), between the catalyst chamber (22) and the upper tube sheet (13), there is provided an igniter (23), and between the upper tube sheet (13) and the igniter (23), there is provided a silver catalyst layer (24).

2. The oxidation reactor equipment for silver-process formaldehyde production according to claim 1, wherein: The adjacent heat exchange tubes (14) are arranged in an equilateral triangle.

3. A kind of oxidation reactor equipment for silver process formaldehyde production according to claim 1, characterized in that: The inner cylinder body anti-seismic flexible thin tube sheet expansion ring assembly (17) includes left and right C-shaped anti-seismic flexible thin tube sheet expansion rings (19) and upper and lower C-shaped anti-seismic expansion rings (18).

4. A kind of oxidation reactor equipment for silver process formaldehyde production according to claim 1, characterized in that: Below the steam riser outlet (3), there is provided a demister (30), and the demister (30) is fixedly connected to the steam riser outlet (3).

5. A kind of oxidation reactor equipment for silver method formaldehyde production according to claim 1, characterized in that: The outer cylinder body expansion ring (8) is of a C-shaped structure.

6. A kind of oxidation reactor equipment for silver method formaldehyde production according to claim 1, characterized in that: The upper tube sheet (13) is of a concave body structure.

7. A kind of oxidation reactor equipment for silver method formaldehyde production according to claim 1, characterized in that: On the outer cylinder body (1), there is provided a sight glass (20).

8. A kind of oxidation reactor equipment for silver method formaldehyde production according to claim 1, characterized in that: On the outer cylinder body (1), there is provided a bracket (21).

9. A kind of oxidation reactor equipment used for silver method formaldehyde production according to claim 1, characterized in that: The wire hose (11) is connected to the upper pipe section of the circulation pipe (10) and the lower pipe section of the circulation pipe (9) through a set of upper and lower flanges respectively.

10. A kind of oxidation reactor equipment for silver method formaldehyde production according to claim 1, characterized in that: The equipment material is austenitic stainless steel.

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