Energy saver capable of preventing acid dew point corrosion

Abstract

The utility model relates to an acid dew point corrosion prevention economizer, which comprises a flue gas inlet, a heating surface box body and a flue gas outlet, the heating surface box body consists of a heat exchange tube and a collecting box, two ends of the heat exchange tube are respectively supported by a left tube plate and a right tube plate, a polyphenylene sulfide coating is sprayed and sintered on the outer surface of the heat exchange tube, and the collecting box is arranged in the collecting box. One end of the heat exchange tube is welded and fixed with the left tube plate through a fixed gland, a sliding sealing assembly is arranged between the other end of the heat exchange tube and the right tube plate, the sliding sealing assembly comprises a gland seat, a movable gland and a ceramic fiber rope, the gland seat is welded in a tube penetrating hole of the right tube plate, the movable gland is sleeved on the heat exchange tube and is in threaded connection with the gland seat, and the ceramic fiber rope is arranged in the gland seat. And the ceramic fiber rope is wound on the heat exchange tube and is positioned on the inner side of the movable gland. The polyphenylene sulfide coatings are sprayed on the heat exchange tube, the tube plate and the flue gas inlet and outlet which are in contact with the flue gas, so that acid dew point corrosion is prevented, and heat exchange equipment can safely operate for a long period below the acid dew point of the flue gas.

Description

Technical Field

[0001] The utility model relates to the technical field of low-temperature heat exchange, in particular to an energy saver capable of preventing acid dew point corrosion. Background Art

[0002] Economizer is a common heat exchange device in boiler equipment, heating furnace equipment, and waste heat recovery system. It further reduces the flue gas temperature, absorbs the flue gas heat, and achieves a more energy-saving effect.

[0003] In order to operate safely, the economizer generally works above the flue gas acid dew point. When the economizer works below the flue gas acid dew point, acid dew point corrosion will occur. Currently, the heat exchange tubes that resist acid dew point corrosion are made of two materials. One is acid corrosion-resistant steel, such as austenitic stainless steel, which is expensive and has a limited service life; the other is enameled tubes. Enameled tubes will experience pinhole corrosion during use, and the corrosion rate is several times that of unenamelled tubes. Both materials cannot guarantee long-term stable operation of the equipment. Summary of the invention

[0004] The utility model aims to overcome the above-mentioned shortcomings and provides an economizer that is resistant to acid dew point corrosion. The heat exchange tubes, tube sheets and flue gas inlet and outlet contacting with flue gas are sprayed with polyphenylene sulfide coating to prevent acid dew point corrosion, so that the heat exchange equipment can operate safely for a long period of time below the flue gas acid dew point.

[0005] The purpose of the utility model is achieved in this way:

[0006] An economizer for preventing acid dew point corrosion comprises a flue gas inlet, a heating surface box and a flue gas outlet, wherein the heating surface box is composed of a heat exchange tube and a header, wherein both ends of the heat exchange tube are supported by a left tube sheet and a right tube sheet respectively, and a polyphenylene sulfide coating is sprayed and sintered on the outer surface of the heat exchange tube, one end of the heat exchange tube is welded and fixed to the left tube sheet by a fixed gland, and a sliding sealing assembly is provided between the other end and the right tube sheet, wherein the sliding sealing assembly comprises a gland seat, a movable gland and a ceramic fiber rope, wherein the gland seat is welded in a tube through-hole of the right tube sheet, the movable gland is sleeved on the heat exchange tube, and the movable gland is threadedly connected to the gland seat, and the ceramic fiber rope is wound around the heat exchange tube and located on the inner side of the movable gland.

[0007] Preferably, the middle of the heat exchange tube is supported by an intermediate tube sheet, and a sleeve is provided between the heat exchange tube and the intermediate tube sheet.

[0008] Preferably, the inner side surface of the left tube sheet, the inner side surface of the right tube sheet and both side surfaces of the middle tube sheet are sprayed and sintered with a polyphenylene sulfide coating.

[0009] Preferably, the inner surfaces of the smoke inlet and the smoke outlet are also sprayed and sintered with a thick polyphenylene sulfide coating.

[0010] Preferably, the outer surface of the movable gland is provided with an external thread, and the inner surface of the gland seat is provided with an internal thread corresponding to the external thread.

[0011] Preferably, the ceramic fiber rope is provided with at least 4 turns.

[0012] Preferably, an O-ring is embedded in the inner end surface of the fixed gland.

[0013] Preferably, the sleeve is made of polytetrafluoroethylene.

[0014] The beneficial effects of the utility model are:

[0015] The heat exchange tubes, tube sheets and flue gas inlet and outlet that are in contact with the flue gas are sprayed with polyphenylene sulfide coating to prevent acid dew point corrosion, so that the heat exchange equipment can operate safely for a long period of time below the flue gas acid dew point;

[0016] The middle of the heat exchange tube is supported by the middle tube sheet, and a sleeve is provided between the heat exchange tube and the middle tube sheet. The sleeve is made of polytetrafluoroethylene to protect the polyphenylene sulfide coating, reduce the vibration of the heat exchange tube, and prevent the heat exchange tube from bending and deformation;

[0017] The sliding seal assembly ensures effective sealing while enabling free thermal expansion of the heat exchange tube along the length direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the utility model.

[0019] Figure 2 for Figure 1 Detailed diagram of the connection between the left tube sheet and the heat exchange tube at I in the middle.

[0020] Figure 3 for Figure 1 Detailed diagram of the connection between the intermediate tube sheet and the heat exchange tube at II.

[0021] Figure 4 for Figure 1 Detailed diagram of the connection between the right tube sheet and the heat exchange tube at III in the middle.

[0022] Among them: flue gas inlet 1; flue gas outlet 2; heat exchange tube 3; header 4; left tube sheet 5; right tube sheet 6; polyphenylene sulfide coating 7; fixed gland 8; gland seat 9; movable gland 10; ceramic fiber rope 11; middle tube sheet 12; sleeve 13; O-ring 14. DETAILED DESCRIPTION

[0023] See also Figure 1-4The utility model relates to an economizer for preventing acid dew point corrosion, comprising a flue gas inlet 1, a heating surface box, an elbow box door and a flue gas outlet 2. The heating surface box is composed of a heat exchange tube 3 and a header 4. The two ends of the heat exchange tube 3 are supported by a left tube sheet 5 and a right tube sheet 6 respectively. The outer surface of the heat exchange tube 3 is sprayed and sintered with a 0.3mm thick polyphenylene sulfide coating 7. One end of the heat exchange tube 3 is welded and fixed to the left tube sheet 5 by a fixed pressure cover 8, and a sliding sealing component is provided between the other end and the right tube sheet 6. The heat exchange tube 3 is connected to the right tube sheet 6 by the sliding sealing component, ensuring effective sealing while realizing free thermal expansion of the heat exchange tube along the length direction. The sliding sealing assembly includes a gland seat 9, a movable gland 10 and a ceramic fiber rope 11. The gland seat 9 is welded in the tube hole of the right tube plate 6. The movable gland 10 is sleeved on the heat exchange tube 3, and the movable gland 10 is threadedly connected to the gland seat 9. The outer surface of the movable gland 10 is provided with an external thread, and the inner surface of the gland seat 9 is provided with an internal thread corresponding to the external thread. The ceramic fiber rope 11 is wound around the heat exchange tube 3 and is located on the inner side of the movable gland 10.

[0024] The ceramic fiber rope 11 is provided with at least 4 turns and is tightly packed to ensure sealing.

[0025] The heat exchange tube 3 is supported by an intermediate tube sheet 12, and a sleeve 13 is provided between the heat exchange tube 3 and the intermediate tube sheet 12. The sleeve 13 is made of polytetrafluoroethylene to protect the polyphenylene sulfide coating, reduce vibration of the heat exchange tube, and prevent bending and deformation of the heat exchange tube.

[0026] The inner side surface of the left tube sheet 5, the inner side surface of the right tube sheet 6 and both side surfaces of the intermediate tube sheet 12 are sprayed and sintered with a 0.3 mm thick polyphenylene sulfide coating 7; the inner surfaces of the flue gas inlet 1 and the flue gas outlet 2 are also sprayed and sintered with a 0.3 mm thick polyphenylene sulfide coating 7. By spraying the polyphenylene sulfide coating 7 at the contact point with the flue gas, acid dew point corrosion is prevented.

[0027] An O-ring 14 is embedded in the inner end surface of the fixed gland 8 .

[0028] In addition to the above embodiments, the present invention also includes other implementation modes. Any technical solutions formed by equivalent transformation or equivalent replacement should fall within the protection scope of the claims of the present invention.

Claims

1. An economizer for preventing acid dew point corrosion, comprising a flue gas inlet, a heating surface box and a flue gas outlet, wherein the heating surface box is composed of a heat exchange tube and a header, and is characterized in that: The two ends of the heat exchange tube are respectively supported by the left tube sheet and the right tube sheet. The outer surface of the heat exchange tube is sprayed and sintered with a polyphenylene sulfide coating. One end of the heat exchange tube is welded to the left tube sheet by a fixed gland, and a sliding sealing assembly is provided between the other end and the right tube sheet. The sliding sealing assembly includes a gland seat, a movable gland and a ceramic fiber rope. The gland seat is welded in the tube through hole of the right tube sheet, the movable gland is sleeved on the heat exchange tube, and the movable gland is threadedly connected to the gland seat. The ceramic fiber rope is wound around the heat exchange tube and is located on the inner side of the movable gland.

2. The economizer for preventing acid dew point corrosion according to claim 1, characterized in that: The middle of the heat exchange tube is supported by an intermediate tube plate, and a sleeve is provided between the heat exchange tube and the intermediate tube plate.

3. The economizer for preventing acid dew point corrosion according to claim 2, characterized in that: The inner side surface of the left tube sheet, the inner side surface of the right tube sheet and both side surfaces of the middle tube sheet are sprayed and sintered with polyphenylene sulfide coating.

4. The economizer for preventing acid dew point corrosion according to claim 1, characterized in that: The inner surfaces of the smoke inlet and the smoke outlet are also sprayed and sintered with a thick polyphenylene sulfide coating.

5. The economizer for preventing acid dew point corrosion according to claim 1, characterized in that: The outer surface of the movable gland is provided with external threads, and the inner surface of the gland seat is provided with internal threads corresponding to the external threads.

6. The economizer for preventing acid dew point corrosion according to claim 1, characterized in that: The ceramic fiber rope is provided with at least 4 turns.

7. The economizer for preventing acid dew point corrosion according to claim 1, characterized in that: An O-shaped sealing ring is embedded in the inner end surface of the fixed gland.

8. The economizer for preventing acid dew point corrosion according to claim 2, characterized in that: The sleeve is made of polytetrafluoroethylene.

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