Indirect steam heating apparatus resistant to strong acid corrosion

Abstract

This invention proposes an indirect steam heating device resistant to strong acid corrosion, belonging to the field of steam heating technology for strong acid corrosion resistance. Addressing the technical problems of existing strong acid environment heating technologies, such as acid concentration dilution, poor corrosion resistance of ordinary materials, low heating efficiency of plastic materials, and small heat exchange area, this invention provides an indirect steam heating device resistant to strong acid corrosion in strong acid environments. It achieves the technical goals of not diluting the acid concentration, long-term resistance to strong acid corrosion, and efficient increase in the temperature of strong acid solutions. Furthermore, by optimizing the pipeline layout to increase the heat exchange area, it further improves heating efficiency, meeting the requirements for efficient oxide layer removal in beryllium copper strip production.

Description

Technical Field

[0001] This invention belongs to the field of steam heating technology resistant to strong acid corrosion, and particularly relates to an indirect steam heating device resistant to strong acid corrosion. Background Technology

[0002] In the production process of beryllium copper strip, an oxide layer forms on the surface of the strip, which needs to be removed in a strong acid environment. The higher the temperature of the strong acid environment, the higher the efficiency of oxide layer removal, which can effectively improve the strip throughput and overall production efficiency. Therefore, achieving efficient heating in a strong acid environment is a key requirement for beryllium copper strip production. However, existing heating methods have many technical defects and are difficult to meet production requirements.

[0003] Currently, the industry mainly uses two methods to heat strong acid environments: one is to directly introduce steam into the strong acid solution for heating; the other is to use ordinary metal or plastic materials to make heating pipes and indirectly heat the strong acid solution through steam.

[0004] The direct steam heating scheme involves directly introducing the steam generated by the steam generator into the reaction tank containing the strong acid solution. Heat exchange is achieved through direct contact between the steam and the strong acid solution, thereby increasing the solution temperature. There are no additional heat exchange structures such as heating pipes.

[0005] The indirect heating scheme using ordinary material pipes is as follows: ordinary metal or plastic heating pipes are installed in the reaction tank. A steam generator introduces steam into the heating pipes through a delivery pipe. The steam releases heat in the pipes and completes heat exchange with the strong acid solution through the pipe walls. The condensate after heat exchange is discharged through a recovery pipe.

[0006] However, direct steam heating inevitably dilutes the concentration of the strong acid solution, reducing the effectiveness of oxide layer removal and affecting the processing quality of beryllium copper strip. Using ordinary metal materials for heating pipes results in insufficient resistance to strong acid corrosion, making long-term stable operation in strong acid environments impossible, leading to high equipment failure rates and short service life. While plastic materials offer some corrosion resistance, their poor thermal conductivity and low heat exchange efficiency make it difficult to quickly raise the temperature of the strong acid solution, failing to meet the demands for increased production efficiency. Existing indirect heating solutions often employ straight pipe layouts, resulting in a small contact area with the strong acid solution, further reducing heating efficiency. Summary of the Invention

[0007] To address the shortcomings of existing strong acid environment heating technologies, such as acid concentration dilution, poor corrosion resistance of ordinary materials, low heating efficiency of plastic materials, and small heat exchange area, this invention provides a strong acid corrosion-resistant indirect steam heating device for strong acid environments. This invention relates to metal material surface treatment technology, specifically applied to the strong acid environment heating stage in the production process of beryllium copper strip.

[0008] This invention discloses an indirect steam heating device resistant to strong acid corrosion. The device includes a steam generator, a steam delivery pipeline, valves, a reaction tank, a heating unit, a fixed support, a condensate recovery pipeline, and a condensate collection device; wherein: The heating unit is built into the reaction tank containing the strong acid solution; the steam generator is connected to the heating unit through a steam delivery pipeline; the heating unit is connected to the condensate collection device through a condensate recovery pipeline; thus forming a complete closed loop of steam delivery-indirect heat exchange-condensate recovery. The steam generator produces heating steam, which is then transported to the heating unit in the reaction tank via a steam delivery pipeline. Valves are installed on the steam delivery pipeline, and the flow rate and the heating rate of the strong acid solution are controlled by adjusting the valves. The main body of the heating unit is a niobium tube. After the steam enters the niobium tube, it exchanges heat with the external strong acid solution through the niobium tube wall. The steam condenses and releases latent heat, thereby raising the temperature of the strong acid solution. The steam only flows inside the niobium tube and does not come into direct contact with the strong acid solution. The condensate after heat exchange flows out from the condensate outlet of the niobium tube and is transported to the external condensate collection device through the condensate recovery pipeline. The niobium tube is fixed in the reaction tank by a fixed bracket, and its structure is stable and will not be displaced due to the flow of solution.

[0009] Preferably, the steam generating device is a steam boiler.

[0010] Preferably, the heating unit uses a single niobium tube, which is arranged in a serpentine pattern inside the reaction tank. Both ends of the niobium tube extend outside the reaction tank and are respectively connected to the steam conveying pipeline and the condensate recovery pipeline through flange seals.

[0011] Preferably, the parts of the steam conveying pipeline and condensate recovery pipeline that come into contact with the strong acid environment are made of PVC material, the fixing brackets are made of titanium alloy material, and a regulating valve is installed on the steam conveying pipeline.

[0012] Preferably, the steam generator produces saturated steam at 0.3 MPa, which is then fed into the serpentine niobium tube through a steam delivery pipeline after the flow rate is regulated by a regulating valve. The steam condenses and exchanges heat inside the niobium tube, heating the strong acid solution in the reaction tank from room temperature to 60°C. The condensate after heat exchange flows into the condensate collection device through a recovery pipeline. The concentration of the strong acid solution remains unchanged throughout the heating process, and the niobium tube does not corrode in the strong acid environment.

[0013] Preferably, the heating unit uses two parallel niobium tubes, both arranged in a coil shape within the reaction tank. The steam inlets of the two niobium tubes are connected in parallel to a steam delivery pipeline, and the condensate outlets are connected in parallel to a condensate recovery pipeline.

[0014] Preferably, the steam conveying pipeline and the condensate recovery pipeline are made of fluoropolymer-lined steel pipe, the fixed support is made of strong acid-resistant engineering plastic, and an electric regulating valve is installed on the steam conveying pipeline to realize automatic temperature control.

[0015] Preferably, the steam generator produces saturated steam at 0.4 MPa. The steam flow rate is automatically adjusted by an electric regulating valve based on the temperature sensor signal in the reaction tank. The steam enters two coiled niobium tubes to exchange heat with the strong acid solution, heating the sulfuric acid solution from 25°C to 70°C. The condensate is collected through a recovery pipeline and then sent back to the steam generator for recycling.

[0016] Preferably, the steam conveying pipes and condensate recovery pipes are made of corrosion-resistant materials, or the parts of them that come into contact with strong acid environments are provided with corrosion-resistant coatings.

[0017] Preferably, the fixing bracket is made of a material resistant to strong acid corrosion.

[0018] In summary, the technical solution provided by this invention achieves the technical goals of not diluting the acid concentration, long-term resistance to strong acid corrosion, and efficient increase in the temperature of strong acid solutions. At the same time, by optimizing the pipeline layout to increase the heat exchange area, the heating efficiency is further improved, meeting the need for efficient removal of oxide layers in the production of beryllium copper strip. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of an indirect steam heating device resistant to strong acid corrosion according to an embodiment of the present invention; Wherein: 1-Steam generator, 2-Steam conveying pipeline, 3-Valve, 4-Reaction tank, 5-Niobium pipe, 6-Fixed support, 7-Condensate recovery pipeline, 8-Condensate collection device. Detailed Implementation

[0021] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] This invention discloses an indirect steam heating device resistant to strong acid corrosion. The device includes a steam generator, a steam delivery pipeline, valves, a reaction tank, a heating unit, a fixed support, a condensate recovery pipeline, and a condensate collection device; wherein: The heating unit is built into the reaction tank containing the strong acid solution; the steam generator is connected to the heating unit through a steam delivery pipeline; the heating unit is connected to the condensate collection device through a condensate recovery pipeline; thus forming a complete closed loop of steam delivery-indirect heat exchange-condensate recovery. The steam generator produces heating steam, which is then transported to the heating unit in the reaction tank via a steam delivery pipeline. Valves are installed on the steam delivery pipeline, and the flow rate and the heating rate of the strong acid solution are controlled by adjusting the valves. The main body of the heating unit is a niobium tube. After the steam enters the niobium tube, it exchanges heat with the external strong acid solution through the niobium tube wall. The steam condenses and releases latent heat, thereby raising the temperature of the strong acid solution. The steam only flows inside the niobium tube and does not come into direct contact with the strong acid solution. The condensate after heat exchange flows out from the condensate outlet of the niobium tube and is transported to the external condensate collection device through the condensate recovery pipeline. The niobium tube is fixed in the reaction tank by a fixed bracket, and its structure is stable and will not be displaced due to the flow of solution.

[0023] Preferably, the steam generating device is a steam boiler.

[0024] Preferably, the heating unit uses a single niobium tube, which is arranged in a serpentine pattern inside the reaction tank. Both ends of the niobium tube extend outside the reaction tank and are respectively connected to the steam conveying pipeline and the condensate recovery pipeline through flange seals.

[0025] Preferably, the parts of the steam conveying pipeline and condensate recovery pipeline that come into contact with the strong acid environment are made of PVC material, the fixing brackets are made of titanium alloy material, and a regulating valve is installed on the steam conveying pipeline.

[0026] Preferably, the steam generator produces saturated steam at 0.3 MPa, which is then fed into the serpentine niobium tube through a steam delivery pipeline after the flow rate is regulated by a regulating valve. The steam condenses and exchanges heat inside the niobium tube, heating the strong acid solution in the reaction tank from room temperature to 60°C. The condensate after heat exchange flows into the condensate collection device through a recovery pipeline. The concentration of the strong acid solution remains unchanged throughout the heating process, and the niobium tube does not corrode in the strong acid environment.

[0027] Preferably, the heating unit uses two parallel niobium tubes, both arranged in a coil shape within the reaction tank. The steam inlets of the two niobium tubes are connected in parallel to a steam delivery pipeline, and the condensate outlets are connected in parallel to a condensate recovery pipeline.

[0028] Preferably, the steam conveying pipeline and the condensate recovery pipeline are made of fluoropolymer-lined steel pipe, the fixed support is made of strong acid-resistant engineering plastic, and an electric regulating valve is installed on the steam conveying pipeline to realize automatic temperature control.

[0029] Preferably, the steam generator produces saturated steam at 0.4 MPa. The steam flow rate is automatically adjusted by an electric regulating valve based on the temperature sensor signal in the reaction tank. The steam enters two coiled niobium tubes to exchange heat with the strong acid solution, heating the sulfuric acid solution from 25°C to 70°C. The condensate is collected through a recovery pipeline and then sent back to the steam generator for recycling.

[0030] Preferably, the steam conveying pipes and condensate recovery pipes are made of corrosion-resistant materials, or the parts of them that come into contact with strong acid environments are provided with corrosion-resistant coatings.

[0031] Preferably, the fixing bracket is made of a material resistant to strong acid corrosion.

[0032] like Figure 1 As shown, the device consists of a steam generator, a steam delivery pipeline, a heating unit, a condensate recovery pipeline, and an external condensate collection device. The heating unit is built into the reaction tank containing the strong acid solution. The steam generator and the heating unit are connected through the steam delivery pipeline, and the heating unit and the condensate collection device are connected through the condensate recovery pipeline, forming a complete closed loop of "steam delivery - indirect heat exchange - condensate recovery". A steam generator (steam boiler) produces heating steam, which is then transported to the heating unit within the reaction tank via a steam delivery pipeline. Valves are installed on the steam delivery pipeline to control the steam's on / off state and flow rate, thereby precisely controlling the heating rate and final temperature of the strong acid solution. The main body of the heating unit is a niobium tube. After entering the niobium tube, the steam exchanges heat with the external strong acid solution through the tube wall. The steam condenses, releasing latent heat and raising the temperature of the strong acid solution. The steam flows only inside the niobium tube and does not directly contact the strong acid solution. The condensate after heat exchange flows out from the niobium tube's condensate outlet and is transported to an external condensate collection device via a condensate recovery pipeline. The condensate can be recycled and reused, achieving resource recycling. The niobium tube is fixedly installed within the reaction tank using a fixed bracket to ensure its structural stability during operation and prevent displacement due to solution flow or other factors.

[0033] Specifically, the steam heating device in the strong acid environment includes a steam generating device 1, a steam conveying pipe 2, a heating unit, and a condensate recovery pipe 7; the heating unit is located inside the reaction tank 4 containing the strong acid solution; the steam generating device 1 is connected to the steam inlet of the heating unit through the steam conveying pipe 2; the condensate outlet of the heating unit is connected to an external condensate collection device 8 through the condensate recovery pipe 7.

[0034] The main body of the heating unit is at least one niobium tube 5, with the two ends of the niobium tube 5 serving as a steam inlet and a condensate outlet, respectively, and is sealed to the steam delivery pipe 2 and the condensate recovery pipe 7.

[0035] The niobium tubes 5 are arranged in a serpentine or coiled shape within the reaction tank 4.

[0036] The steam conveying pipeline 2 and the condensate recovery pipeline 7 are made of corrosion-resistant materials, or the parts of them that come into contact with strong acid environments are coated with corrosion-resistant materials.

[0037] The steam transmission pipeline 2 is equipped with a valve 3.

[0038] The heating unit also includes a fixing bracket 6, through which the niobium tube 5 is fixed in the reaction tank 4.

[0039] The fixed bracket 6 is made of a material resistant to strong acid corrosion.

[0040] The following is a detailed description of Embodiment 1 (Serpentine Niobium Tube Heating Device) of the present invention.

[0041] Device structure: The heating unit uses a single niobium tube, which is arranged in a serpentine pattern inside the reaction tank. Both ends of the niobium tube extend outside the reaction tank and are respectively connected to the steam delivery pipeline and the condensate recovery pipeline through flange sealing. The parts of the steam delivery pipeline and the condensate recovery pipeline that come into contact with the strong acid environment are made of PVC material. The fixing bracket is made of titanium alloy material, and a manual regulating valve is installed on the steam delivery pipeline.

[0042] Implementation process: The steam generator produces saturated steam at 0.3 MPa. After the steam flow rate is adjusted by a manual regulating valve through the steam delivery pipeline, the steam enters the serpentine niobium tube. The steam condenses and exchanges heat inside the niobium tube, heating the strong acid solution (sulfuric acid solution) in the reaction tank from room temperature to 60°C. The condensate after heat exchange flows into the condensate collection device through the recovery pipeline. The concentration of the strong acid solution does not change during the entire heating process, and the niobium tube does not show any corrosion in the strong acid environment.

[0043] Implementation results: The serpentine arrangement increases the contact area between the niobium tube and the strong acid solution by more than 5 times compared to the straight tube, significantly improving the heat exchange efficiency and increasing the solution heating rate by 80% compared to the plastic pipe; the device can operate continuously and stably for more than 3000 hours.

[0044] The following is a detailed description of Embodiment 2 of the present invention (coil-shaped niobium tube heating device).

[0045] Device structure: The heating unit uses two parallel niobium tubes, both arranged in a coil shape within the reaction tank. The steam inlets of the two niobium tubes are connected in parallel to the steam delivery pipeline, and the condensate outlets are connected in parallel to the condensate recovery pipeline. The steam delivery pipeline and the condensate recovery pipeline are made of fluoropolymer-lined steel pipes, and the fixed supports are made of strong acid-resistant engineering plastics. An electric regulating valve is installed on the steam delivery pipeline to achieve automatic temperature control.

[0046] Process: The steam generator produces saturated steam at 0.4 MPa. The steam flow rate is automatically adjusted by an electric regulating valve based on the temperature sensor signal in the reaction tank. The steam enters two coiled niobium tubes to exchange heat with the strong acid solution, heating the sulfuric acid solution from 25°C to 70°C. The condensate is collected through a recovery pipeline and then sent back to the steam generator for recycling.

[0047] Implementation results: The heat exchange area of ​​the double-coil niobium tube is twice that of the single serpentine niobium tube, and the solution heating rate is further improved, meeting the heating requirements of large-scale beryllium copper strip production; the electric regulating valve achieves precise temperature control, with temperature fluctuation range controlled within ±2℃; the fluoropolymer-lined steel tube and engineering plastic support have excellent corrosion resistance, and the equipment maintenance cycle is extended to more than 6 months.

[0048] Compared with the prior art, the technical solution of the present invention has the following significant advantages: (1) Excellent corrosion resistance. Using niobium tubes as the main body of the heating unit, the excellent resistance of niobium metal to strong acid corrosion is utilized, which solves the problem of the poor corrosion resistance of ordinary metal materials, enabling the device to work stably in a strong acid environment for a long time and greatly extending the service life of the equipment; (2) High heating efficiency. Niobium tubes have good thermal conductivity, which is far superior to low thermal conductivity materials such as plastics, and can quickly realize the heat exchange between steam and strong acid solution, thereby increasing the solution heating rate; at the same time, the niobium tubes are arranged in a serpentine / coil shape, which increases the contact area with the strong acid solution and further improves the heat exchange efficiency; (3) Ensure stable acid concentration. Through indirect heating, the steam only flows inside the niobium tubes and does not come into direct contact with the strong acid solution, which completely avoids the problem of acid concentration dilution and ensures the stability of the oxide layer removal effect of beryllium copper strip; (4) Precise control and convenient operation. Valves are installed on the steam conveying pipeline to flexibly control the steam on / off and flow rate, and to achieve precise adjustment of the temperature of the strong acid solution. The overall structure of the device is simple, easy to install and maintain, and suitable for large-scale industrial production applications; (5) Resource recycling. Condensate recovery pipelines and collection devices are installed to recycle and reuse the condensate after heat exchange, reducing production water and steam consumption and saving production costs; (6) Strong overall adaptability. The steam conveying pipeline, condensate recovery pipeline and fixed support are all made of strong acid resistant materials or treated with corrosion resistance, forming a matching corrosion resistant structure with the niobium pipe, which improves the overall adaptability of the device to the strong acid environment.

[0049] In summary, the technical solution provided by this invention achieves the technical goals of not diluting the acid concentration, long-term resistance to strong acid corrosion, and efficient increase in the temperature of strong acid solutions. At the same time, by optimizing the pipeline layout to increase the heat exchange area, the heating efficiency is further improved, meeting the need for efficient removal of oxide layers in the production of beryllium copper strip.

[0050] To expand the scope of protection and achieve the same inventive purpose, the technical solution of this application can be replaced by the following structural / device replacements. All replacement solutions can achieve the effects of strong acid corrosion resistance and efficient indirect heating: (1) Replacement of niobium tubes: Niobium alloy tubes can be used to replace pure niobium tubes. While maintaining excellent strong acid corrosion resistance and thermal conductivity, niobium alloy tubes have higher mechanical strength and are suitable for high-pressure steam heating scenarios; (2) Replacement of pipe materials: For the parts of steam conveying pipes and condensate recovery pipes that come into contact with strong acids, PP material or polytetrafluoroethylene tubes can be used to replace PVC pipes or fluoropolymer-lined steel pipes, all of which can achieve good corrosion resistance; (3) Replacement of valves: Pneumatic regulating valves can be used to replace manual / electric regulating valves, which are suitable for the remote control needs of industrial automated production lines; (4) Replacement of fixed supports: Hastelloy can be used to replace titanium alloys or strong acid-resistant engineering plastics. Hastelloy has stronger corrosion resistance and is suitable for higher concentrations of strong acid environments; (5) Replacement of niobium tube arrangement: "U-shaped series" can be used. The arrangement can replace the serpentine or coiled shape, and can still effectively increase the heat exchange area in scenarios where the space of the reaction tank is limited.

[0051] Please note that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The above embodiments only illustrate several implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims

1. An indirect steam heating device resistant to strong acid corrosion, characterized in that, The device includes a steam generator, a steam delivery pipeline, valves, a reaction tank, a heating unit, a fixed support, a condensate recovery pipeline, and a condensate collection device; wherein: The heating unit is built into the reaction tank containing the strong acid solution; the steam generator is connected to the heating unit through a steam delivery pipeline; the heating unit is connected to the condensate collection device through a condensate recovery pipeline; thus forming a complete closed loop of steam delivery-indirect heat exchange-condensate recovery. The steam generator produces heating steam, which is then transported to the heating unit in the reaction tank via a steam delivery pipeline. Valves are installed on the steam delivery pipeline, and the flow rate and the heating rate of the strong acid solution are controlled by adjusting the valves. The main body of the heating unit is a niobium tube. After the steam enters the niobium tube, it exchanges heat with the external strong acid solution through the niobium tube wall. The steam condenses and releases latent heat, thereby raising the temperature of the strong acid solution. The steam only flows inside the niobium tube and does not come into direct contact with the strong acid solution. The condensate after heat exchange flows out from the condensate outlet of the niobium tube and is transported to the external condensate collection device through the condensate recovery pipeline. The niobium tube is fixed in the reaction tank by a fixed bracket, and its structure is stable and will not be displaced due to the flow of solution.

2. The indirect steam heating device according to claim 1, wherein The steam generating device is a steam boiler.

3. The indirect steam heating device of claim 1, wherein, The heating unit uses a single niobium tube, which is arranged in a serpentine pattern inside the reaction tank. Both ends of the niobium tube extend outside the reaction tank and are respectively connected to the steam conveying pipeline and the condensate recovery pipeline through flange seals.

4. The indirect steam heating device of claim 3, wherein, The parts of the steam delivery pipeline and condensate recovery pipeline that come into contact with the strong acid environment are made of PVC material, the fixed supports are made of titanium alloy material, and the steam delivery pipeline is equipped with a regulating valve.

5. The indirect steam heating device resistant to strong acid corrosion according to claim 4, characterized in that: The steam generator produces saturated steam at 0.3 MPa. After the steam flow rate is regulated by a regulating valve through the steam delivery pipeline, the steam enters the serpentine niobium tube. The steam condenses and exchanges heat inside the niobium tube, heating the strong acid solution in the reaction tank from room temperature to 60°C. The condensate after heat exchange flows into the condensate collection device through the recovery pipeline. The concentration of the strong acid solution remains unchanged throughout the heating process, and the niobium tube does not corrode in the strong acid environment.

6. The indirect steam heating device of claim 1, wherein, The heating unit uses two parallel niobium tubes, both arranged in a coil shape within the reaction tank. The steam inlets of the two niobium tubes are connected in parallel to the steam delivery pipeline, and the condensate outlets are connected in parallel to the condensate recovery pipeline.

7. A steam heating apparatus according to claim 6, wherein The steam transmission pipeline and condensate recovery pipeline are made of fluoropolymer-lined steel pipe, and the fixed supports are made of strong acid-resistant engineering plastic. The steam transmission pipeline is equipped with an electric regulating valve to achieve automatic temperature control.

8. The indirect steam heating device resistant to strong acid corrosion according to claim 7, characterized in that: The steam generator produces saturated steam at 0.4 MPa. The steam flow rate is automatically adjusted by an electric regulating valve based on the temperature sensor signal in the reaction tank. The steam enters two coiled niobium tubes to exchange heat with the strong acid solution, heating the sulfuric acid solution from 25°C to 70°C. The condensate is collected through a recovery pipeline and then sent back to the steam generator for recycling.

9. The indirect steam heating device of claim 1, wherein, Steam transport pipelines and condensate recovery pipelines are made of corrosion-resistant materials, or the parts of them that come into contact with strong acid environments are coated with corrosion-resistant materials.

10. The indirect steam heating device of claim 1, wherein, The mounting bracket is made of a material resistant to strong acid corrosion.

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