Air heater for waste heat recovery system of sulfuric acid device

Abstract

The utility model relates to the technical field of waste heat recovery systems of sulfuric acid devices, in particular to an air heater for a waste heat recovery system of a sulfuric acid device. Comprising a shell, comb-shaped plates are arranged on the upper side and the lower side in the shell respectively, a plurality of sheet-shaped units are connected between the comb-shaped plates on the upper side and the lower side, and the adjacent sheet-shaped units are alternately arranged in the vertical direction. Compared with the prior art, a heat exchange structure of the air heater is formed through the modularized sheet-shaped units, the sheet-shaped units are installed in a split mode, the number of finned tubes can be increased or decreased conveniently, if individual heat exchange tubes or elbows are damaged and fail after equipment runs, the whole sheet-shaped units can be independently taken out and replaced, and the situation that the heat exchange area of the equipment is reduced due to tube blocking is avoided. The structure is simple, materials are saved, a supporting pore plate is prevented from being used for supporting the heat exchange tube, and the drilling procedure and material waste of the supporting pore plate are reduced. The multiple sets of snake-shaped heat exchange tube rows can be welded and subjected to 100% radiographic inspection at the same time and do not interfere with one another, the production efficiency can be greatly improved, the manufacturing period is shortened, and it can be guaranteed that the snake-shaped heat exchange tube rows cannot be damaged or fail under the condition that the snake-shaped heat exchange tube rows make contact with acid mist.

Description

Technical Field

[0001] The utility model relates to the technical field of waste heat recovery systems for sulfuric acid devices, in particular to an air heater used in waste heat recovery systems for sulfuric acid devices. Background Art

[0002] During the production process of sulfuric acid, considerable heat is generated. This heat is usually recycled in the form of steam to produce medium- and high-pressure steam and low-pressure steam according to the different waste heat temperatures in different links. The first link in sulfuric acid production is the combustion of sulfur or other sulfur-containing raw materials. The temperature of the air supporting combustion is relatively low. If the air can be heated and then used for combustion, the temperature of the combustion product process gas can be increased, and then the output of medium- and high-pressure steam can be increased. In view of this, an air heater for the waste heat recovery system of the sulfuric acid device is needed.

[0003] Considering that acid mist may enter the air when the sulfuric acid device fails, in order to ensure that the welds of the serpentine heat exchange tubes are still reliable when exposed to acid mist, it is necessary to perform 100% radiographic inspection on all butt welds of the serpentine heat exchange tubes. In conventional serpentine heat exchangers, when the heat exchange tubes are compactly arranged, the elbows of adjacent serpentine heat exchange tubes affect each other, and their butt welds can only be partially inspected by radiography, and the reliability of the serpentine heat exchange tubes cannot be guaranteed. In addition, most of the serpentine heat exchange tubes are fixed by punching holes in the support plate, which is a complicated process. Utility Model Content

[0004] In order to overcome the deficiencies of the prior art, the utility model provides an air heater for a waste heat recovery system of a sulfuric acid device, which can utilize high-temperature water, high-temperature steam or high-temperature concentrated sulfuric acid to heat air and then use it for combustion-supporting of sulfur or other sulfur-containing raw materials, thereby increasing the temperature of the combustion product process gas and subsequently increasing the output of medium and high-pressure steam in the waste heat recovery system of the sulfuric acid device.

[0005] To achieve the above purpose, an air heater for a waste heat recovery system of a sulfuric acid device is designed, comprising a shell, wherein comb plates are respectively provided on the upper and lower sides of the shell, a plurality of sheet units are connected between the comb plates on the upper and lower sides, and adjacent sheet units are alternately arranged in positive and negative directions in the upper and lower directions.

[0006] The sheet unit includes a serpentine heat exchange tube row, a corrugated clamp, and a connecting rod. The comb plate is connected to one end of the connecting rod, and the other end of the connecting rod is connected to several corrugated clamps. A serpentine heat exchange tube row is arranged between the connecting rods on the upper and lower sides, and the serpentine heat exchange tube row is fixed on the corrugated clamp.

[0007] The serpentine heat exchange tube row comprises a plurality of straight fin tubes and elbows. The plurality of straight fin tubes are arranged in parallel, and adjacent fin tubes are connected by elbows to form a serpentine structure.

[0008] One end of the serpentine heat exchange tube row passes through the shell and is connected to the header through a straight pipe joint or an elbow pipe joint.

[0009] The connection between the serpentine heat exchange tube array and the shell is sealed and welded.

[0010] The corrugated clamping plate is provided with a plurality of semicircular corrugated protrusions for the serpentine heat exchange tube rows to pass through.

[0011] One side of the comb-shaped plate is provided with a plurality of evenly distributed keyhole slots.

[0012] The diameter of the circular hole portion of the keyhole groove is 1-3 mm larger than the outer diameter of the connecting rod.

[0013] The structure of the connecting rod is a cylindrical hollow structure, and a mounting hole is provided on one side of the connecting rod. The size of the mounting hole is twice the size of the cross-section of the corrugated clamping plate.

[0014] The structure of the shell is a box structure, and the upper and lower surfaces of the shell are open structures.

[0015] Compared with the prior art, the utility model has the following beneficial effects:

[0016] 1. The heat exchange structure of the air heater is formed by modular sheet units, which are installed in pieces to facilitate increasing or decreasing the number of fin tubes. If individual heat exchange tubes or elbows are damaged and fail after the equipment is running, the sheet unit can be taken out and replaced separately to avoid tube blockage and reduce the heat exchange area of ​​the equipment.

[0017] 2. The structure is simple, material saving, avoiding the use of supporting orifice plates to support the heat exchange tubes, and reducing the drilling process and material waste of the supporting orifice plates.

[0018] 3. Multiple groups of serpentine heat exchange tubes can be welded and 100% X-ray inspected at the same time without interfering with each other, which can greatly improve production efficiency, reduce manufacturing cycle, and ensure that they will not be damaged or fail when exposed to acid mist. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of the utility model after removing one side plate of the shell.

[0020] Figure 2 It is a cross-sectional view of the utility model.

[0021] Figure 3 It is a side view of the utility model.

[0022] Figure 4 It is a structural schematic diagram of the sheet unit of the utility model.

[0023] Figure 5It is a structural schematic diagram of the serpentine heat exchange tube array of the utility model.

[0024] Figure 6 It is a structural schematic diagram of the comb-shaped plate of the utility model. DETAILED DESCRIPTION

[0025] The utility model is further described below with reference to the accompanying drawings.

[0026] like Figures 1 to 6 As shown, comb plates 2 are provided on the upper and lower sides of the shell 1, and a plurality of sheet units 7 are connected between the comb plates 2 on the upper and lower sides. Adjacent sheet units 7 are alternately arranged in the up and down directions to avoid mutual interference between adjacent sheet units 7.

[0027] The sheet unit 7 includes a serpentine heat exchange tube row 3, a corrugated clamp plate 4, and a connecting rod 5. The comb plate 2 is connected to one end of the connecting rod 5, and the other end of the connecting rod 5 is connected to several corrugated clamp plates 4. A serpentine heat exchange tube row 3 is arranged between the connecting rods 5 on the upper and lower sides, and the serpentine heat exchange tube row 3 is fixed on the corrugated clamp plate 4.

[0028] The serpentine heat exchange tube row 3 includes a plurality of straight fin tubes 3-1 and elbows 3-2. The plurality of straight fin tubes 3-1 are arranged in parallel, and adjacent fin tubes 3-1 are connected by elbows 3-2 to form a serpentine structure.

[0029] One end of the serpentine heat exchange tube row 3 passes through the shell 1 and is connected to the header 6 through a straight pipe joint 8 or an elbow pipe joint 9. The medium flowing in the header 6 to heat the air is high-temperature water or high-temperature steam.

[0030] The connection between the serpentine heat exchange tube bank 3 and the shell 1 is sealed and welded. The part of the serpentine heat exchange tube bank 3 located inside the shell 1 can expand freely in the lateral direction.

[0031] The corrugated clamping plate 4 is provided with a plurality of semicircular corrugated protrusions 4-1 for the serpentine heat exchange tube row 3 to pass through. The radius of the semicircular corrugated protrusions 4-1 matches the outer diameter of the serpentine heat exchange tube row 3.

[0032] A plurality of evenly distributed keyhole slots 2-1 are provided on one side of the comb plate 2. When used specifically, the number of the comb plates 2 is 3 or more. Figure 6 As shown, the keyhole groove 2-1 is composed of a long hole and a round hole, and the diameter of the round hole portion 2-11 of the keyhole groove 2-1 is 1-3 mm larger than the outer diameter of the connecting rod 5. The keyhole groove 2-1 plays a role in lateral guidance and vertical limitation for the sheet unit 7 composed of the serpentine heat exchange tube row 3, the corrugated clamping plate 4 and the connecting rod 5.

[0033] The structure of the connecting rod 5 is a cylindrical hollow structure. A mounting hole is provided on one side of the connecting rod 5. The size of the mounting hole is twice the cross-sectional size of the corrugated clamping plate 4, so as to facilitate the insertion and fixation of a pair of corrugated clamping plates 4.

[0034] The structure of the shell 1 is a box structure, and the upper and lower surfaces are open square flanges as the inlet and outlet of air. The shell 1 is surrounded by side panels.

[0035] The manufacturing method of the above air heater comprises the following steps:

[0036] S1, assembling the sheet unit 7: the serpentine heat exchange tube row 3 is clamped and supported by a plurality of corrugated clamping plates 4, and then the two ends of the corrugated clamping plates 4 are fixed with connecting rods 5 and connected in series to form a sheet unit 7; S2, a plurality of groups of comb plates are respectively welded at the two open ends of the shell 1; S3, a plurality of groups of sheet units are inserted into the shell 1 through the key-shaped hole grooves of the comb plates 2; S4, the serpentine heat exchange tube row 3 is extended out of the side plate of the shell 1 for sealing welding, and the upper and lower ports of the serpentine heat exchange tube row 3 are connected to the header 6 through the straight pipe joint 8 or the elbow pipe joint 9.

[0037] Before step S1, 100% radiographic inspection is performed on the butt welds between the fin tubes 3-1 and the elbows 3-2 in the serpentine heat exchange tube row 3 to ensure that the butt welds between the fin tubes 3-1 and the elbows 3-2 are still reliable when acid mist may enter the air due to a malfunction of the sulfuric acid device.

[0038] In the utility model, a plurality of sheet-like units can be manufactured at the same time, and the welding and 100% radiographic inspection of each sheet-like unit are not limited by space and are not affected by other sheet-like units.

[0039] The utility model comprises a serpentine heat exchange tube row 3, a corrugated clamp plate 4 and a connecting rod 5, and a plurality of groups of the sheet units can be welded and non-destructively tested at the same time without interfering with each other, which can greatly improve production efficiency and shorten the manufacturing cycle. The corrugated clamp plate 4 replaces the supporting orifice plate of the conventional heat exchanger, reducing the drilling process and material waste of the supporting orifice plate. It can also ensure that it will not be damaged and fail in the case of contact with acid mist. Even if individual heat exchange tubes or elbows are damaged and fail after the equipment is in operation, the entire heat exchange tube row can be taken out and replaced to avoid pipe blockage and reduce the heat exchange area of ​​the equipment.

Claims

1. An air heater for a waste heat recovery system of a sulfuric acid plant, comprising a housing, characterized in that: Comb-shaped plates (2) are respectively provided on the upper and lower sides of the housing (1); a plurality of sheet-like units (7) are connected between the comb-shaped plates (2) on the upper and lower sides; and adjacent sheet-like units (7) are arranged alternately in a positive and negative direction in the upper and lower directions.

2. The air heater for a waste heat recovery system of a sulfuric acid plant according to claim 1, characterized in that: The sheet unit (7) comprises a serpentine heat exchange tube row (3), a corrugated clamping plate (4), and a connecting rod (5); the comb plate (2) is connected to one end of the connecting rod (5); the other end of the connecting rod (5) is connected to a plurality of corrugated clamping plates (4); a serpentine heat exchange tube row (3) is provided between the connecting rods (5) at the upper and lower sides; and the serpentine heat exchange tube row (3) is fixed on the corrugated clamping plate (4).

3. The air heater for a waste heat recovery system of a sulfuric acid plant according to claim 2, characterized in that: The serpentine heat exchange tube row (3) comprises a plurality of straight finned tubes (3-1) and elbows (3-2); the plurality of straight finned tubes (3-1) are arranged in parallel, and adjacent finned tubes (3-1) are connected via elbows (3-2) to form a serpentine structure.

4. An air heater for a waste heat recovery system of a sulfuric acid plant according to claim 2 or 3, characterized in that: One end of the serpentine heat exchange tube bank (3) passes through the shell (1) and is connected to the header (6) via a straight pipe joint (8) or an elbow pipe joint (9).

5. The air heater for a waste heat recovery system of a sulfuric acid plant according to claim 4, characterized in that: The connection between the serpentine heat exchange tube array (3) and the shell (1) is sealed and welded.

6. The air heater for a waste heat recovery system of a sulfuric acid plant according to claim 2, characterized in that: The corrugated clamping plate (4) is provided with a plurality of semicircular corrugated protrusions (4-1) for the serpentine heat exchange tube array (3) to pass through.

7. The air heater for a waste heat recovery system of a sulfuric acid plant according to claim 1, characterized in that: One side of the comb-shaped plate (2) is provided with a plurality of evenly distributed keyhole slots (2-1).

8. The air heater for a waste heat recovery system of a sulfuric acid plant according to claim 7, characterized in that: The diameter of the circular hole portion (2-11) of the keyhole-shaped hole groove (2-1) is 1 to 3 mm larger than the outer diameter of the connecting rod (5).

9. The air heater for a waste heat recovery system of a sulfuric acid plant according to claim 2, characterized in that: The structure of the connecting rod (5) is a cylindrical hollow structure. A mounting hole is provided on one side of the connecting rod (5). The size of the mounting hole is twice the cross-sectional size of the corrugated clamping plate (4).

10. The air heater for a waste heat recovery system of a sulfuric acid plant according to claim 1, characterized in that: The structure of the shell (1) is a box structure, and the upper and lower surfaces of the shell (1) are open structures.

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