Heat insulation device at welding position of heat exchange tube and tube plate

Abstract

The utility model relates to a heat insulation device at the welding position of a heat exchange tube and a tube plate, which comprises the tube plate, the heat exchange tube, a calcium silicate insulation board, a stainless steel pressing plate, a stainless steel anti-loose sleeve and a stainless steel bolt, the tube plate is welded with the heat exchange tube, the calcium silicate insulation board is arranged outside the tube plate, the stainless steel pressing plate is arranged outside the calcium silicate insulation board, and the stainless steel anti-loose sleeve is arranged outside the stainless steel pressing plate. The stainless steel pressing plate, the calcium silicate heat preservation plate and the tube plate are connected through stainless steel bolts, and the stainless steel anti-loose sleeve sequentially penetrates through the stainless steel pressing plate and the calcium silicate heat preservation plate and then is inserted into the heat exchange tube. The heat exchanger effectively prevents the welding joints of the heat exchange tubes and the tube plate from being in direct contact with a low-temperature medium, avoids alternation of cold and hot stress of the welding joints, effectively improves the performance and prolongs the service life of the heat exchanger.

Description

Technical Field

[0001] The utility model relates to the technical field of heat exchange equipment, in particular to a heat insulation device at the welded joint of a heat exchange tube and a tube sheet. Background Technique

[0002] In many cases in heat exchange equipment, high-temperature media and / or low-temperature media are not continuously introduced. For example, in a molecular sieve waste nitrogen heater, during use, high-temperature steam is continuously introduced, while low-temperature waste nitrogen is not continuously introduced. Generally, low-temperature nitrogen stops after being introduced for a period of time and is introduced again after a period of time, and the time interval between two introductions of nitrogen is relatively long.

[0003] As Figure 1 shown, usually the tube sheet 1 of the heat exchange equipment is directly welded and fixed to the heat exchange tube 2. In this case, if the high-temperature medium is in the shell side and the low-temperature medium is in the tube side, during the period when the low-temperature medium stops being introduced, the tube sheet will heat up due to heat conduction. When the low-temperature medium is introduced again, the welded joint between the heat exchange tube at the inlet side and the tube sheet will directly contact the low-temperature medium and cool down rapidly, thereby generating thermal stress, which may seriously affect the effectiveness of the welded joint between the heat exchange tube and the tube sheet in severe cases. Content of the Utility Model

[0004] The purpose of the utility model is to overcome the above deficiencies and provide a heat insulation device at the welded joint of a heat exchange tube and a tube sheet, which prevents the welded joint of the heat exchange tube and the tube sheet from generating thermal alternating stress. Calcium silicate insulation board with good heat insulation performance and certain proven processability is selected as the insulation layer, effectively avoiding the direct contact between the welded joint of the heat exchange tube and the tube sheet and the low-temperature medium, avoiding the alternation of cold and hot stresses at the welded joint, and effectively improving the performance and service life of the heat exchanger.

[0005] The purpose of the utility model is achieved as follows:

[0006] A heat insulation device at the welded joint of a heat exchange tube and a tube sheet includes a tube sheet, a heat exchange tube, a calcium silicate insulation board, a stainless steel pressing plate, a stainless steel anti-loosening sleeve, and a stainless steel bolt. The tube sheet is welded to the heat exchange tube, and a calcium silicate insulation board is arranged outside the tube sheet. The calcium silicate insulation board is arranged on the inlet side of the heat exchange tube. A stainless steel pressing plate is arranged outside the calcium silicate insulation board. The stainless steel pressing plate, the calcium silicate insulation board, and the tube sheet are connected by stainless steel bolts. The stainless steel anti-loosening sleeve passes through the stainless steel pressing plate and the calcium silicate insulation board in sequence and is inserted into the heat exchange tube.

[0007] Preferably, the tube sheet is provided with threaded holes corresponding to the stainless steel bolts.

[0008] Preferably, the calcium silicate insulation board is provided with bolt sleeves corresponding to the stainless steel bolts, and the bolt sleeves are embedded in the bolt holes of the calcium silicate insulation board.

[0009] Preferably, the inner end of the stainless steel anti-loosening sleeve is provided with a flared opening, and the outer end is provided with a retaining edge. The side of the retaining edge of the stainless steel anti-loosening sleeve is spot-welded and fixed to the stainless steel pressing plate.

[0010] Preferably, the stainless steel pressing plate is semicircular, the stainless steel bolts are distributed around the stainless steel pressing plate, and the calcium silicate insulation board is adapted to the stainless steel pressing plate.

[0011] The beneficial effects of the present utility model are as follows:

[0012] The present utility model effectively avoids the direct contact between the welded joint of the heat exchange tube and the tube sheet and the low-temperature medium, avoids the alternating of thermal and cold stresses at the welded joint, and effectively improves the performance and service life of the heat exchanger. Description of the Drawings

[0013] Figure 1 It is a schematic structural diagram of the connection structure between the heat exchange tube and the tube sheet in the prior art.

[0014] Figure 2 It is a schematic structural diagram of a heat insulation device at the welded joint of a heat exchange tube and a tube sheet of the present utility model.

[0015] Figure 3 It is Figure 2 a partial enlarged view of

[0016] Figure 4 It is a schematic diagram of the inner end structure of the stainless steel anti-loosening sleeve.

[0017] Figure 5 It is a schematic diagram of the distribution of the stainless steel bolts.

[0018] Wherein: tube sheet 1; heat exchange tube 2; calcium silicate insulation board 3; stainless steel pressing plate 4; stainless steel anti-loosening sleeve 5; stainless steel bolt 6; bolt sleeve 7. Detailed Embodiment

[0019] Refer to Figure 2-5, the utility model relates to a heat insulation device at the welded joint of a heat exchange tube and a tube sheet, which comprises a tube sheet 1, a heat exchange tube 2, a calcium silicate insulation board 3, a stainless steel pressing plate 4, a stainless steel anti-loosening sleeve 5, a stainless steel bolt 6 and a bolt sleeve 7. The tube sheet 1 is welded to the heat exchange tube 2, and the tube head of the heat exchange tube 2 is flush with the outer surface of the tube sheet 1. A calcium silicate insulation board 3 is arranged outside the tube sheet 1. The calcium silicate insulation board 3 is arranged on the inlet side of the heat exchange tube 2. A stainless steel pressing plate 4 is arranged outside the calcium silicate insulation board 3. The stainless steel pressing plate 4, the calcium silicate insulation board 3 and the tube sheet 1 are connected by a stainless steel bolt 6. The tube sheet 1 is provided with a threaded hole corresponding to the stainless steel bolt 6. The calcium silicate insulation board 3 is provided with a bolt sleeve 7 corresponding to the stainless steel bolt 6. The bolt sleeve 7 is embedded in the bolt hole of the calcium silicate insulation board 3, so that the stainless steel bolt 6 can smoothly pass through the calcium silicate insulation board 3 without damaging the calcium silicate insulation board 3. The end of the stainless steel bolt 6 is spot-welded and fixed to the stainless steel pressing plate 4.

[0020] The stainless steel anti-loosening sleeve 5 sequentially passes through the stainless steel pressing plate 4 and the calcium silicate insulation board 3 and then is inserted into the heat exchange tube 2, pressing the stainless steel pressing plate 4 and the calcium silicate insulation board 3 against the tube sheet 1.

[0021] The inner end of the stainless steel anti-loosening sleeve 5 is provided with a flared opening, and the outer end is provided with a retaining edge. The flared surface of the flared opening forms an angle of 15° with the horizontal. After flaring, the peripheral sharp corners are rounded. The maximum diameter of the stainless steel anti-loosening sleeve is smaller than the inner diameter of the heat exchange tube, and the difference between the two is not more than 0.3 mm. The thickness of the retaining edge is not less than the wall thickness of the stainless steel anti-loosening sleeve, and the diameter of the retaining edge is larger than the diameter of the tube hole on the stainless steel pressing plate, so that the retaining edge is limited outside the stainless steel pressing plate.

[0022] The stainless steel pressing plate 4 is semicircular, and the stainless steel bolts 6 are distributed around the stainless steel pressing plate 4. The calcium silicate insulation board is adapted to the stainless steel pressing plate.

[0023] Installation method:

[0024] First, weld the tube sheet 1 to the heat exchange tube 2. After the tube sheet 1 and the heat exchange tube 2 are welded and expanded, the exposed part of the tube head is cut and polished to be flush with the outer surface of the tube sheet.

[0025] The stainless steel anti-loosening sleeve 5 passes through the stainless steel pressing plate 4 and the calcium silicate insulation board 3 and then is inserted into the heat exchange tube 2. The retaining edge side of the stainless steel anti-loosening sleeve 5 is spot-welded and fixed to the stainless steel pressing plate 4.

[0026] The stainless steel bolt 6 sequentially passes through the stainless steel pressing plate 4 and the calcium silicate insulation board 3 and then is fixed to the tube sheet 1.

[0027] By arranging a heat insulation device at the welded joint of the heat exchange tube and the tube sheet, the alternating change of thermal stress and cold stress at the welded joint of the heat exchange tube and the tube sheet can be effectively avoided, and the performance and service life of the heat exchanger can be effectively improved.

[0028] In addition to the above embodiments, the present utility model also includes other implementation manners. Any technical solutions formed by equivalent transformation or equivalent substitution shall fall within the protection scope of the claims of the present utility model.

Claims

1. A heat insulation device at the welded joint of a heat exchange tube and a tube sheet, characterized in that: It includes a tube sheet, heat exchange tubes, calcium silicate insulation boards, stainless steel pressing plates, stainless steel anti-loosening sleeves and stainless steel bolts. The tube sheet is welded to the heat exchange tubes. A calcium silicate insulation board is provided outside the tube sheet. The calcium silicate insulation board is arranged on the inlet side of the heat exchange tubes. A stainless steel pressing plate is provided outside the calcium silicate insulation board. The stainless steel pressing plate, calcium silicate insulation board and tube sheet are connected by stainless steel bolts. The stainless steel anti-loosening sleeve sequentially passes through the stainless steel pressing plate and calcium silicate insulation board and then is inserted into the heat exchange tube.

2. The heat insulation device at the welded joint of the heat exchange tube and the tube sheet according to claim 1, characterized in that: The tube sheet is provided with threaded holes corresponding to the stainless steel bolts.

3. The heat insulation device at the welded joint of the heat exchange tube and the tube sheet according to claim 1, characterized in that: The calcium silicate insulation board is provided with bolt sleeves corresponding to the stainless steel bolts, and the bolt sleeves are embedded in the bolt holes of the calcium silicate insulation board.

4. The heat insulation device at the welded joint of a heat exchange tube and a tube sheet according to claim 1, characterized in that: The inner end of the stainless steel anti-loosening sleeve is provided with a flared opening, and the outer end is provided with a flange. The flange side of the stainless steel anti-loosening sleeve is spot-welded and fixed to the stainless steel pressing plate.

5. The heat insulation device at the welded joint of a heat exchange tube and a tube sheet according to claim 1, characterized in that: The stainless steel pressing plate is semicircular, and the stainless steel bolts are distributed around the stainless steel pressing plate. The calcium silicate insulation board is adapted to the stainless steel pressing plate.

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