A three-section cracking gas heat exchanger of a waste acid treatment high-temperature cracking furnace converter

Abstract

The utility model discloses a three-stage cracking gas heat exchanger for a waste acid disposal high-temperature cracking furnace converter, which comprises a connecting pipe, an upper gas box and a lower gas box. A plurality of heat exchange pipes are coaxially fixed in the connecting pipe; a cooling gas inlet pipe communicating with the inner cavity thereof is fixed on the upper side wall of the upper end of the connecting pipe, and a cooling gas outlet pipe communicating with the inner cavity thereof is fixed on the lower side wall of the lower end; the upper gas box is fixed at the upper end of the connecting pipe, and a cracking gas outlet pipe communicating with the inner cavity thereof is fixed on one side part of the upper gas box; the lower gas box is fixed at the lower end of the connecting pipe, and a cracking gas inlet pipe communicating with the inner cavity thereof is fixed on the side wall of the lower gas box; wherein, two ends of the heat exchange pipe respectively communicate with the inner cavities of the upper gas box and the lower gas box. In the utility model, the inner cavities of the upper gas box and the lower gas box form an air chamber to communicate with the connecting pipe, and the heat exchange pipe extends into the air chamber. The cracking gas is transitioned through the upper gas box and the lower gas box, thereby improving the stable operation of the heat exchanger.

Description

Technical Field

[0001] This utility model relates to the field of waste acid treatment technology, and more specifically to a three-stage pyrolysis gas heat exchanger for a high-temperature pyrolysis furnace converter for waste acid treatment. Background Technology

[0002] A waste acid pyrolysis furnace is a high-temperature device used to treat industrial waste acid. It converts waste acid into reusable gaseous or liquid products through high-temperature pyrolysis, simultaneously achieving the harmless treatment of the waste acid. Waste acid pyrolysis furnaces can transform waste acid into useful chemicals and energy, and have broad application prospects.

[0003] The working principle of a waste acid pyrolysis furnace is to decompose the organic matter and sulfuric acid in waste acid using a high-temperature environment. The waste acid is atomized through a spray gun and enters the pyrolysis furnace. Under the high temperature (approximately 1000℃) inside the furnace, the waste acid undergoes pyrolysis and combustion reactions. During the pyrolysis process, the organic matter in the waste acid is oxidized and decomposed, while the sulfuric acid is decomposed into gases such as sulfur dioxide (SO2) and water vapor. These gases then enter subsequent purification, conversion, and absorption units, ultimately producing high-purity sulfuric acid or other useful products.

[0004] The temperature of the cracked gas discharged from the fluidized bed furnace reaches 950-1000°C. The alkylated waste sulfuric acid is pumped into the roasting furnace through an acid pump, and the temperature is controlled to be maintained at 950-1000°C. The waste sulfuric acid is cracked at this high temperature to produce SO2 gas, and the organic matter in it is simultaneously burned into CO2. This mixed gas and the SO2 gas produced by the combustion of pyrite together form furnace gas. The furnace gas is then purified and refined, i.e., cooled, washed, demisted and dried, to obtain qualified SO2 furnace gas. The furnace gas is then converted and absorbed to produce qualified sulfuric acid.

[0005] Currently, existing heat exchangers are prone to significant thermal stress due to the temperature difference between the shell and tube sides, especially when the temperature difference is large, which affects the reliability and safe operation of the heat exchangers.

[0006] Therefore, how to provide a heat exchanger that operates safely and stably is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0007] In view of this, the present invention provides a three-stage pyrolysis gas heat exchanger for a high-temperature pyrolysis furnace converter for waste acid treatment, aiming to solve the above-mentioned technical problems.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A three-stage pyrolysis gas heat exchanger for a high-temperature pyrolysis furnace converter for waste acid treatment includes:

[0010] A connecting pipe, wherein multiple heat exchange tubes are coaxially fixed inside the connecting pipe; a cooling gas inlet pipe communicating with its inner cavity is fixed to the upper side wall of the connecting pipe, and a cooling gas outlet pipe communicating with its inner cavity is fixed to the lower side wall.

[0011] The upper gas box is fixed at the upper end of the connecting pipe, and a pyrolysis gas outlet pipe communicating with its inner cavity is fixed on one side of the upper gas box.

[0012] The lower gas box is fixed to the lower end of the connecting pipe, and a pyrolysis gas inlet pipe communicating with its inner cavity is fixed to the side wall of the lower gas box.

[0013] The two ends of the heat exchange tube are respectively connected to the inner cavities of the upper air box and the lower air box.

[0014] The beneficial effects of this utility model are that, through the connecting pipe between the upper and lower gas boxes, the pyrolysis gas enters the heat exchange tube from the lower gas box and flows out from the upper gas box; the cooling gas enters the connecting pipe from the upper end and flows outside the multiple heat exchange tubes, and flows out from the lower end of the connecting pipe to complete heat exchange with the pyrolysis gas in the connecting pipe. The upper and lower gas boxes can improve the stability of the heat exchanger operation.

[0015] Preferably, tube sheets are fixed at both ends of the connecting pipe, and the outer wall of the heat exchange tube is embedded in the tube holes of the tube sheet, with its two ends extending into the inner cavities of the upper and lower air boxes, respectively. The tube sheet is a honeycomb plate, and multiple heat exchange tubes are fixed inside the connecting pipe through the honeycomb holes on the tube sheet.

[0016] Preferably, the lower gas box is a pipe body, with a sealing plate fixed at one end away from the connecting pipe. The inner bottom wall of the sealing plate is provided with an isolation layer, an acid-resistant mortar layer, and an acid-resistant brick from bottom to top. A lower manhole pipe communicating with the inner cavity of the lower gas box is fixed to the side wall opposite to the pyrolysis gas inlet pipe. The sealing plate seals the lower gas box to prevent pyrolysis gas overflow. Since pyrolysis gas is a high-temperature acidic gas, the isolation layer, acid-resistant mortar layer, and acid-resistant brick improve the performance and lifespan of the heat exchanger. The lower manhole pipe facilitates cleaning of the lower gas box.

[0017] Preferably, the device further includes a support tube, the two ends of which are fixed to the sealing plate and the panel of the tube sheet located at the lower end of the connecting tube, respectively. The support tube is supported inside the lower air box to ensure the stable operation of the heat exchanger.

[0018] Preferably, the device further includes annular plates and disc plates; there are multiple annular plates, which are spaced apart and fitted onto the outer walls of multiple heat exchange tubes; the disc plates are fitted onto the outer walls of the heat exchange tubes between adjacent annular plates; the outer diameter of the disc plates is smaller than the outer diameter of the annular plates. The annular plates and disc plates form a baffle channel within the connecting tube, improving heat exchange efficiency.

[0019] Preferably, the device further includes a tie rod and a spacer tube. The tie rod passes through the annular plate and the disc plate; the spacer tube is sleeved around the outer periphery of the tie rod, and its two ends abut against the opposite panels of the annular plate and the disc plate, respectively. The tie rod passing through the annular plate and the disc plate, and the spacer tube located between the annular plate and the disc plate, ensures a uniform distance between the disc plate and the annular plate, preventing displacement of the annular plate and the disc plate during heat exchanger operation.

[0020] Preferably, both ends of the tie rod are welded and fixed to the tube sheet located at both ends of the connecting pipe. Welding the tie rod to the tube sheet can provide support for multiple heat exchange tubes and reduce the impact of vibration on the heat exchange tubes.

[0021] Preferably, an expander is embedded in the middle of the connecting pipe, and the expander has through holes for the multiple heat exchange tubes to pass through. During operation of the heat exchanger, the heat exchange tubes and tube sheet will undergo thermal displacement due to thermal expansion, and the expander absorbs this displacement, thereby reducing the thermal stress caused by the temperature difference between the tube and shell sides, improving the reliability of the heat exchanger, and ensuring the safe and stable operation of the heat exchanger.

[0022] Preferably, the upper gas box is a pipe body, with a top cover fixed to the end away from the connecting pipe; an upper manhole pipe communicating with the inner cavity of the upper gas box is fixed to the side wall of the upper gas box relative to the pyrolysis gas outlet pipe. The top cover seals the upper gas box to prevent pyrolysis gas leakage, and the upper manhole pipe facilitates cleaning of the upper gas box.

[0023] Preferably, an acid discharge pipe communicating with the inner cavity of the lower gas box is fixed to the lower end of the acid discharge pipe, and a ball valve is fixed to the outlet of the acid discharge pipe away from the lower gas box. The acid accumulated on the sealing plate of the lower gas box can be discharged through the acid discharge pipe.

[0024] As can be seen from the above technical solution, compared with the prior art, this utility model discloses a three-stage pyrolysis gas heat exchanger for a high-temperature pyrolysis furnace converter for waste acid treatment. The upper and lower gas boxes form a gas chamber connecting pipe, and the heat exchange tube extends into the gas chamber. The pyrolysis gas is transferred through the upper and lower gas boxes, which improves the stable operation of the heat exchanger. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0026] Figure 1 A cross-sectional view of the heat exchanger provided by this utility model;

[0027] Figure 2A side view of the heat exchanger provided by this utility model;

[0028] Figure 3 for Figure 1 Enlarged diagram of part A in the diagram;

[0029] Figure 4 for Figure 1 Enlarged schematic diagram of part B in the diagram;

[0030] Figure 5 for Figure 1 Enlarged schematic diagram of part C in the diagram;

[0031] Figure 6 for Figure 1 Enlarged schematic diagram of part D in the diagram.

[0032] in,

[0033] 1-Lower gas box; 11-Cracked gas inlet pipe; 12-Lower manhole pipe; 13-Acid discharge pipe; 14-Support pipe; 15-Sealing plate; 16-Isolation layer; 17-Acid-resistant mortar layer; 18-Acid-resistant brick;

[0034] 2-Connecting pipe; 21-Cooling air inlet pipe; 22-Cooling air outlet pipe; 23-Tie rod; 24-Annular plate; 25-Disc plate; 26-Tube sheet; 27-Spacing tube;

[0035] 3-Upper gas box; 31-Upper manhole pipe; 32-Cracked gas outlet pipe; 33-Top cover;

[0036] 4-Heat exchange tubes;

[0037] 5-Expander. Detailed Implementation

[0038] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0039] See appendix Figure 1 ~6, This utility model embodiment discloses a three-stage pyrolysis gas heat exchanger for a high-temperature pyrolysis furnace converter for waste acid treatment, comprising:

[0040] Connecting pipe 2, with multiple heat exchange tubes 4 coaxially fixed inside the connecting pipe 2; a cooling gas inlet pipe 21 communicating with its inner cavity is fixed to the upper side wall of the connecting pipe 2, and a cooling gas outlet pipe 22 communicating with its inner cavity is fixed to the lower side wall.

[0041] Upper gas box 3 is fixed at the upper end of connecting pipe 2, and a pyrolysis gas outlet pipe 32 that connects to its inner cavity is fixed on one side of upper gas box 3.

[0042] The lower gas box 1 is fixed to the lower end of the connecting pipe 2, and the side wall of the lower gas box 1 is fixed with a cracked gas inlet pipe 11 that communicates with its inner cavity.

[0043] The two ends of the heat exchange tube 4 are connected to the inner cavities of the upper air box 3 and the lower air box 1, respectively.

[0044] like Figure 2 As shown, the heat exchange tubes are bolt-operated, with multiple tubes evenly distributed within the inner cavity of the connecting tube, such as... Figure 1 As shown, the upper and lower gas boxes are fixed at both ends of the connecting pipe, and the inner cavities of the upper and lower gas boxes serve as gas chambers to contain the cracked gas. The cracked gas fills the gas chambers and enters the heat exchange tube. The cracked gas enters from the bottom and exits from the top, while the cooling gas enters the inner cavity of the connecting pipe from both ends in a high-inlet and low-outlet manner. Heat exchange occurs between the high-level cracked gas and the low-temperature cooling gas to reduce the temperature of the cracked gas and ensure the stable operation of the heat exchanger.

[0045] To further optimize the above technical solution, an expander 5 is embedded in the middle of the connecting pipe 2, and the expander 5 has through holes for multiple heat exchange tubes 4 to pass through. During heat exchanger operation, the heat exchange tubes and tube sheet will undergo thermal displacement due to thermal expansion, and the expander absorbs this displacement, thereby reducing the thermal stress caused by the temperature difference between the shell and tube sides, improving the reliability of the heat exchanger, and ensuring its safe and stable operation.

[0046] In this embodiment, in order to ensure that the connector is evenly fixed in the connecting tube, tube plates 26 are fixed at both ends of the connecting tube 2. The outer wall of the heat exchange tube 4 is embedded in the tube hole of the tube plate 26 and its two ends extend into the inner cavity of the upper air box 3 and the lower air box 1, respectively.

[0047] The tube sheet is a honeycomb plate with heat exchange tubes inserted through the honeycomb holes in a ring array. The tube sheet is welded and fixed to the inner wall of the connecting tube along its axis. Multiple air holes for cooling air flow are opened on the panel of the tube sheet located at the upper end of the connecting tube.

[0048] In this embodiment, the lower gas box 1 is a pipe body, and a sealing plate 15 is fixed at one end away from the connecting pipe 2. The inner bottom wall of the sealing plate 15 is provided with an isolation layer 16, an acid-resistant mortar layer 17 and an acid-resistant brick 18 from bottom to top. A lower manhole pipe 12 communicating with its inner cavity is fixed on the side wall of the lower gas box 1 relative to the pyrolysis gas inlet pipe 11.

[0049] The upper end of the lower gas box tube is welded and fixed to the lower end of the connecting pipe. A sealing plate is welded to the lower end to seal the lower gas box opening. Since the lower gas box is the intake of acidic pyrolysis gas, the acid corrosion resistance of the lower gas box is improved by the isolation layer, acid-resistant mortar layer and acid-resistant brick on the sealing plate, thereby improving the service life of the heat exchanger. One end of the lower manhole pipe is welded to the side wall of the lower gas box tube and the two are connected in the inner cavity. The other end is hinged with a lower manhole cover. By opening the lower manhole cover, the inner wall of the lower gas box can be cleaned.

[0050] To further optimize the above technical solution and ensure the stable operation of the heat exchanger, a support tube 14 is also included. The two ends of the support tube 14 are fixed to the panel of the sealing plate 15 and the tube sheet 26 located at the lower end of the connecting tube 2, respectively.

[0051] In this embodiment, the upper gas box 3 is a pipe body, and a top cover 33 is fixed at the end away from the connecting pipe 2; an upper manhole pipe 31 communicating with the inner cavity of the upper gas box 3 is fixed on the side wall of the upper gas box 3 relative to the pyrolysis gas outlet pipe 32.

[0052] The lower end of the upper gas box pipe is welded and fixed to the upper end of the connecting pipe. The upper end of the lower gas box is sealed by a top cover to prevent the leakage of pyrolysis gas. One end of the upper manhole pipe is welded to the side wall of the upper gas box and the two are connected in the inner cavity. The other end is hinged with an upper manhole cover. By opening the upper manhole cover, the dust cleaning operation of the inner wall of the upper gas box can be achieved.

[0053] To further optimize the above technical solution, sleeves are welded between the upper air box pipe body and the connecting pipe body joint, and between the lower air box pipe body and the connecting pipe body joint. The pipe openings of the upper air box, connecting pipe and lower air box are connected by the sleeves, which ensures the integrity of the whole, and the interface position can be sealed by the sleeves to prevent gas leakage.

[0054] In this embodiment, it also includes annular plates 24 and disc plates 25; there are multiple annular plates 24, which are spaced apart and fitted on the outer wall of multiple heat exchange tubes 4; disc plates 25 are fitted on the outer wall of the heat exchange tubes 4 between two adjacent annular plates 24; the outer diameter of the disc plate 25 is smaller than the outer diameter of the annular plate 24.

[0055] The ring plate has circular holes for cooling air to pass through. The ring plate and the disc plate are arranged at intervals, and the diameter of the ring plate is larger than that of the disc plate. Through the cooperation of the ring plate and the disc plate, the flow path of the cooling air in the connecting pipe is deflected to ensure heat exchange efficiency.

[0056] To further optimize the above technical solution, a pull rod 23 and a spacer tube 27 are also included. The pull rod 23 passes through the ring plate 24 and the disc plate 25. The spacer tube 27 is sleeved on the outer periphery of the pull rod 23, and its two ends abut against the two opposite panels of the ring plate 24 and the disc plate 25, respectively.

[0057] The spacer tube is sleeved on the tie rod, and its two ends abut against the two panels opposite the ring plate and the disc plate to fix the distance between the ring plate and the disc plate and prevent the ring plate and the disc plate from shifting during operation.

[0058] To further optimize the above technical solution, the two ends of the tie rod 23 are welded and fixed to the tube sheet 26 located at both ends of the connecting pipe 2. The tie rod is fixed to the tube sheet, and the combination of the tie rod and the spacer tube can form a relatively rigid support structure, which can effectively support the heat exchange tube and prevent the heat exchange tube from vibrating violently.

[0059] In this embodiment, an acid discharge pipe 13 communicating with its inner cavity is fixed at the lower end of the lower gas box 1, and a ball valve is fixed at the pipe opening of the acid discharge pipe 13 away from the lower gas box 1.

[0060] Due to the heat exchange process, some acid will condense and accumulate in the lower air box. When the heat exchanger is shut down, the ball valve is opened to drain the acid accumulated at the bottom of the lower air box through the acid drain pipe to prevent the acidic liquid from corroding the lower air box.

[0061] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0062] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A three-stage pyrolysis gas heat exchanger for a high-temperature pyrolysis furnace converter for waste acid treatment, characterized in that, include: A connecting pipe (2) has multiple heat exchange tubes (4) coaxially fixed inside it; a cooling gas inlet pipe (21) is fixed to the upper side wall of the connecting pipe (2) and a cooling gas outlet pipe (22) is fixed to the lower side wall. Upper gas box (3), the upper gas box (3) is fixed at the upper end of the connecting pipe (2), and a pyrolysis gas outlet pipe (32) communicating with its inner cavity is fixed on one side of the upper gas box (3). The lower gas box (1) is fixed at the lower end of the connecting pipe (2), and the side wall of the lower gas box (1) is fixed with a cracked gas inlet pipe (11) that communicates with its inner cavity. The heat exchange tube (4) is connected to the inner cavity of the upper gas box (3) and the lower gas box (1) at both ends respectively; the connecting tube (2) is fixed with tube sheet (26) at both ends, the outer wall of the heat exchange tube (4) is embedded in the tube hole of the tube sheet (26) and its two ends extend into the inner cavity of the upper gas box (3) and the lower gas box (1) respectively; the lower gas box (1) is a tube body, and a sealing plate (15) is fixed at one end away from the connecting tube (2). The inner bottom wall of the sealing plate (15) is provided with an isolation layer (16), an acid-resistant mortar layer (17) and an acid-resistant brick (18) from bottom to top; the lower gas box (1) is fixed with a lower manhole pipe (12) that connects to its inner cavity on the side wall of the pyrolysis gas inlet pipe (11).

2. The three-stage pyrolysis gas heat exchanger for a high-temperature pyrolysis furnace converter for waste acid treatment according to claim 1, characterized in that, It also includes a support tube (14), the two ends of which are fixed to the sealing plate (15) and the panel of the tube plate (26) located at the lower end of the connecting tube (2), respectively.

3. The three-stage pyrolysis gas heat exchanger for a high-temperature pyrolysis furnace converter for waste acid treatment according to claim 1, characterized in that, It also includes annular plates (24) and disc plates (25); there are multiple annular plates (24), which are spaced apart and fitted on the outer walls of multiple heat exchange tubes (4); the disc plates (25) are fitted on the outer walls of the heat exchange tubes (4) between two adjacent annular plates (24); the outer diameter of the disc plates (25) is smaller than the outer diameter of the annular plates (24).

4. The three-stage pyrolysis gas heat exchanger for a high-temperature pyrolysis furnace converter for waste acid treatment according to claim 3, characterized in that, It also includes a pull rod (23) and a spacer tube (27), the pull rod (23) passing through the ring plate (24) and the disc plate (25); the spacer tube (27) is sleeved on the outer periphery of the pull rod (23), and its two ends abut against the two opposite panels of the ring plate (24) and the disc plate (25), respectively.

5. The three-stage pyrolysis gas heat exchanger for a high-temperature pyrolysis furnace converter for waste acid treatment according to claim 4, characterized in that, The two ends of the pull rod (23) are respectively welded and fixed to the tube sheet (26) located at both ends of the connecting pipe (2).

6. The three-stage pyrolysis gas heat exchanger for a high-temperature pyrolysis furnace converter for waste acid treatment according to claim 1, characterized in that, An expander (5) is embedded in the middle of the connecting pipe (2), and the expander (5) has through holes for the multiple heat exchange tubes (4) to pass through.

7. The three-stage pyrolysis gas heat exchanger for a high-temperature pyrolysis furnace converter for waste acid treatment according to claim 1, characterized in that, The upper gas box (3) is a pipe body, and a top cover (33) is fixed at one end away from the connecting pipe (2); the upper gas box (3) is fixed with an upper manhole pipe (31) that communicates with its inner cavity on the side wall of the pyrolysis gas outlet pipe (32).

8. The three-stage pyrolysis gas heat exchanger for a high-temperature pyrolysis furnace converter for waste acid treatment according to claim 1, characterized in that, The lower end of the lower gas box (1) is fixed with an acid discharge pipe (13) that communicates with its inner cavity, and a ball valve is fixed at the opening of the acid discharge pipe (13) away from the lower gas box (1).

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