Sleeving method of petrochemical shell and tube heat exchanger in cantilever mode

Abstract

The invention discloses a hanging type sleeving method for a petrochemical tubular heat exchanger. Relates to the heat exchanger field. In the field of installation of existing heat exchangers, welding is usually carried out on an internal vertical pipe frame, a penetrating pipe and an exposed pipe end, but an internal groove needs to be adopted for a built-in tube pass end socket, internal welding is carried out, and the quality cannot be guaranteed. The tube plate and the end socket assembly are welded in advance and qualified in flaw detection, the half baffle plate and the central tube are fixed through the connecting mechanism, falling in the sleeving process is prevented, and the half baffle plate and the central tube are disassembled after sleeving; the perpendicularity of the central tube and the tube plate is considered, and a suspension wire or a level gauge is adopted for measuring and confirming that welding flaw detection is qualified; two clamp structures are adopted, one end is fixed by a hanging beam bolt, and the other end of the hanging beam is additionally provided with a counterweight; and the hoop is clamped on the direct pipe section of the end socket assembly and is fixed by a bolt. And finally, after the middle pipe frame is completed, two ends of a hanging beam are connected with a sealing head assembly and a counter weight, and after the counter weight is verified through test hoisting, hoisting and sleeving are carried out, manual wire drawing is assisted, and sleeving in place is guaranteed. The invention is applied to the field of heat exchanger installation.

Description

Technical Field

[0001] The present invention relates to the field of heat exchangers, and particularly to a pick-type assembling method for a petrochemical shell-and-tube heat exchanger. Background Art

[0002] In the field of heat exchanger products, a certain waste heat recovery device has a jacket inside the shell of the shell side, and then a semi-segment baffle is arranged outside the central tube, and it is placed inside the shell. The conventional process method is to install the internal riser frame, insert the tubes, and weld the exposed tube ends, but the internal tube-side head needs to use an internal bevel and enter the inside for welding.

[0003] At present, when the internal tube-side head of this kind of heat recovery device uses an internal bevel and enters the inside for welding, it will cause limited operating space. The internal space of the heat recovery device is limited. When the welder operates inside, the activity range is small, and it is difficult to maintain a comfortable and stable welding posture, which affects the welding accuracy and operation flexibility, resulting in poor weld formation and welding defects. At the same time, the internal environment is relatively closed and the light is insufficient, and the structure of the internal bevel of the head may block the line of sight, making it difficult for the welder to clearly observe the state of the welding molten pool and unable to adjust the welding parameters in time, thus affecting the welding quality. For example, problems such as lack of fusion and lack of penetration may occur.

[0004] At the same time, harmful gases and fumes will be generated during the welding process. The ventilation conditions inside the heat recovery device are poor, and these harmful substances are difficult to discharge, which will not only endanger the physical health of the welder, but also may affect the welding quality, such as causing defects such as pores.

[0005] Moreover, after the internal welding is completed, due to space and structural limitations, it is difficult to conduct quality inspections on the welded joints, such as non-destructive testing, etc., and it is difficult to comprehensively and accurately detect welding defects. Even if defects are found, it will be very difficult to repair them.

[0006] Therefore, when using an internal bevel for welding the internal tube-side head and entering the inside for welding, the quality of the tube-side head cannot be guaranteed. Summary of the Invention

[0007] In order to solve the problems in the existing heat exchanger installation field, usually the internal riser frame is installed, the tubes are inserted, and the exposed tube ends are welded, but the internal tube-side head needs to use an internal bevel and enter the inside for welding, and the quality cannot be guaranteed. Therefore, the present invention provides a pick-type assembling method for a petrochemical shell-and-tube heat exchanger, which improves the efficiency of the riser frame and assembling, avoids the welding difficulties of the circumferential welds, and ensures the manufacturing quality.

[0008] The technical solution of the present invention is as follows:

[0009] A pick-type assembling method for a petrochemical shell-and-tube heat exchanger, the method comprising the following steps;

[0010] Step 1: Welding of tube sheet and head assembly:

[0011] Weld the tube sheet and the head assembly in advance and pass the flaw detection to provide a fixed position for the subsequent casing; the head assembly and the tube sheet are connected by a circumferential weld;

[0012] The connection method of this circumferential weld:

[0013] Cleaning: Carefully clean the oil stains, rust, moisture and other impurities on the parts to be welded of the tube sheet and the head assembly to ensure that the welding area shows metallic luster and avoid affecting the welding quality.

[0014] Assembly: Correctly install the head assembly on the tube sheet to ensure that the concentricity and assembly clearance between the two meet the design requirements, and the assembly clearance can ensure the fusion quality of the weld;

[0015] Spot welding fixation: Carry out spot welding evenly distributed on the circumference to fix the relative positions of the head assembly and the tube sheet, prevent misalignment during the welding process, and determine the number and spacing of spot welds according to factors such as the size and thickness of the tube sheet and the head assembly.

[0016] Step 2: Half baffles and central tube:

[0017] Use a connecting mechanism to fix the half baffles and the central tube to prevent them from falling off during the casing process and remove them after casing;

[0018] The half baffles are accurately installed at the specified positions on the central tube and fixed by a connecting mechanism to ensure that the half baffles will not shift or shake during the casing process, thus ensuring the relative position accuracy between components and making the internal structure of the heat exchanger meet the design requirements;

[0019] During the casing operation, since the connection between the half baffles and the central tube is not firm when not fully fixed, the connecting mechanism will provide additional fastening force to prevent the half baffles and the central tube from falling off during the casing process;

[0020] The temporary fixing structure for falling off during the casing process. After completing the assembly work of the heat exchanger casing, remove the connecting mechanism to prevent affecting the relative positions of the assembled half baffles and the central tube, and at the same time, prevent leaving too many marks on the components or causing damage to the components;

[0021] Step 3: Considering the perpendicularity of the central tube and the tube sheet, use a plumb line or a level to measure and confirm, and pass the welding flaw detection;

[0022] Setting of reference points: Set one or more reference points at appropriate and stable positions around the heat exchanger. The heights of the reference points should be kept the same and ensure that they will not be disturbed and change during the whole measurement process. Use a level to measure and adjust the heights of the reference points to make them on the same horizontal plane;

[0023] Initial measurement of the tube sheet: Vertically place the scale at the edge of the tube sheet or specific measurement points, and use a level to read the scale value on the scale. At different positions on the tube sheet, such as the four corners of the edge or more evenly distributed points, conduct multiple measurements, record the readings of each measurement point, and by comparing these readings, the horizontality of the tube sheet can be preliminarily judged;

[0024] Measurement of the central tube: Vertically place the scale along the outer wall of the central tube, and conduct measurements at different height positions of the central tube. Similarly, use a level to read the scale value on the scale and record it;

[0025] Adjustment and leveling: According to the measurement results, adjust the tube sheet or the central tube. If the tube sheet is not horizontal, it can be adjusted by adding or reducing gaskets at the bottom of the tube sheet; if the central tube is not vertical, it can be made vertical by adjusting the support structure or fixing device of the central tube. During the adjustment process, it is necessary to continuously use a level for measurement until the tube sheet reaches a horizontal state and the central tube reaches a vertical state;

[0026] Step 4: Hoisting beam hoisting:

[0027] Design two clamp structures, fix one end with a hoisting beam bolt, and add a counterweight to the other end of the hoisting beam. Calculate in advance the weight of the counterweight hoisted on the hoisting beam; the clamp is stuck on the straight pipe section of the head assembly and fixed with bolts to play the role of the hoop of the clamp;

[0028] Determine the parameters of the hoisting beam and the head assembly, clarify the weight of the hoisting beam and its center of gravity position, the weight of the object to be hoisted, and its hanging position on the hoisting beam;

[0029] Measure the distance, measure the distance from the lifting point to the center of gravity of the object to be hoisted, and the distance from the lifting point to the other end of the hoisting beam, the position where the counterweight is installed;

[0030] Step 5: Pipe support sleeving:

[0031] After the pipe support is completed, connect it with a hoisting beam. After verifying the counterweight by trial hoisting, fix the outer shell in the installation area and use manual wire drawing assistance to ensure that the sleeving is in place;

[0032] During the process of lifting the pipe support, cooperate with the hoisting equipment. The hoisting equipment lifts the pipe support, and the pipe support is lifted and moved by the hoisting equipment to gradually approach the outer shell;

[0033] At the same time, arrange a special person to observe the insertion situation of the pipe support and the outer shell behind the pipe support, and timely adjust the direction and strength of lifting and hoisting to ensure that the pipe support can be accurately inserted into the outer shell;

[0034] When a part of the pipe end of the pipe support is inserted into the outer shell, more of the pipe support can be inserted through further lifting and fine adjustment. Repeat the above operations until the pipe support is completely sleeved into the outer shell.

[0035] Furthermore, the connecting mechanism adopts a clamp structure, and the semi-baffle plate and the central tube are disassembled and installed through the clamp structure;

[0036] Furthermore, the connecting mechanism is a U-shaped plate structure, and the notch on the connecting mechanism is inserted into the central tube. Installation holes are provided on the connecting mechanism, and bolts are inserted into the installation holes. The bolts pass through the installation holes on the connecting mechanism and the heat exchanger on the semi-baffle plate to install a group of semi-baffle plates into the central tube.

[0037] Furthermore, the head assembly has a straight-through section, and two identical clamps are clamped on the straight-through section of the head assembly to lift the head assembly through the two clamps.

[0038] Furthermore, the clamp is composed of two C-shaped steel plates, and the two C-shaped steel plates on the clamp are arranged in an overlapping manner.

[0039] Furthermore, the arc surfaces of the two C-shaped steel plates on the clamp are attached to the outer side of the straight-through section of the head assembly, and the two clamps are in a parallel structure.

[0040] Furthermore, an upper insertion hole is provided above the clamp, and a lower insertion hole is provided below the clamp;

[0041] A bolt assembly is installed between the upper insertion hole and the lower insertion hole to fixedly connect the two C-shaped steel plates of the clamp.

[0042] Furthermore, after the upper insertion hole of the clamp is aligned with the hole position of the lifting beam, it is fixedly connected to the lifting beam through a bolt assembly.

[0043] Furthermore, side support plates are installed on the lifting beam and are fixedly connected to the clamp through the side support plates on the lifting beam.

[0044] Furthermore, one end of the lifting beam lifts the head assembly, and a counterweight is hung at the other end of the lifting beam.

[0045] The present invention has the following effects compared with the prior art:

[0046] Combined with the product structure, in order to reduce the quality risk of the conventional manufacturing method, the present invention adopts the method of an external riser support. The inner head is welded to the tube sheet in advance and qualified, and then the riser support is carried out to avoid the key welds that are most difficult to be qualified. For the tube-to-tube sheet welds welded later, the number is small and the quality is easy to guarantee.

[0047] The present invention greatly improves the operation efficiency of the riser rack, while avoiding the difficulty of all-position welding of the head weld, ensuring stable product quality, shortening the production cycle, realizing continuous operation of the product, providing a choice of manufacturing method for similar products, expanding the thinking of manufacturing processes and methods, and also providing reference for the manufacture of other new products.

[0048] By designing a semi-baffle fixing device and a pick-type lifting fixing clamp, the present invention realizes the external standing of the pipe rack for convenient operation; at the same time, a suitable counterweight is calculated, and the lifting beam is used for lifting, and the clamp fixes the straight pipe part of the head component to realize lifting the empty pipe rack for sleeving. This method improves the manufacturing efficiency, avoids the uncontrollable quality problem of the internal all-position welding of the head circumferential weld, ensures the product quality, improves the work efficiency, ensures the continuity of product manufacturing, improves the product contract fulfillment ability, and further improves the core manufacturing ability of the company's gasification products, providing reference for similar products.

[0049] The present invention takes the pre-welding and qualified flaw detection of the tube sheet and the head component to provide a fixed position for subsequent sleeving; a designed connecting mechanism is used to fix the semi-baffle and the center pipe to prevent falling off during the sleeving process and is removed after sleeving; considering the perpendicularity of the center pipe and the tube sheet, plumb line or level measurement is taken for confirmation, and the welding flaw detection is qualified; at the same time, a two-clamp structure is adopted, one end is fixed by the lifting beam bolt, and a counterweight is added to the other end of the lifting beam, which is calculated in advance; the clamp is clamped on the straight pipe section of the head component and fixed by bolts to play the role of the hoop of the clamp. Finally, after the middle pipe rack is completed, the two ends of the lifting beam are connected to the head component and the counterweight, and after the counterweight is verified by test lifting, the sleeving is carried out with the assistance of manual wire drawing to ensure the sleeving in place. Brief Description of the Drawings

[0050] Figure 1 is the structural schematic diagram of the present invention;

[0051] Figure 2 is the structural schematic diagram when the lifting beam lifts the pipe rack;

[0052] Figure 3 is the structural schematic diagram of the lifting beam;

[0053] Figure 4 is the left view of the lifting beam;

[0054] Figure 5 is the connection structural schematic diagram of the clamp;

[0055] Figure 6 is the structural schematic diagram of a single clamp;

[0056] Figure 7 is the schematic diagram of the connecting mechanism connecting the semi-baffle and the center pipe;

[0057] Figure 8It is a schematic structural diagram of a pipe support;

[0058] In the figure: 1. tube sheet, 2. head assembly, 3. connecting mechanism, 4. semi-baffle, 5. central tube, 6. clamp, 7. pipe support, 8. outer shell, 9. upper socket, 10. lower socket, 11. hanging beam, 12. side support plate, 13. counterweight. Specific implementation mode

[0059] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments in conjunction with the accompanying drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0060] Specific implementation mode one: Combine Figure 1 — Figure 2 To illustrate this implementation mode, a sleeving method for a pick-type petrochemical shell-and-tube heat exchanger in this implementation mode includes the following steps;

[0061] Step one: Weld the tube sheet and the head assembly:

[0062] Weld the tube sheet 1 and the head assembly 2 in advance and pass the flaw detection to provide a fixed position for subsequent sleeving; the head assembly 2 and the tube sheet 1 are connected by a circumferential weld;

[0063] The connection method of this circumferential weld:

[0064] Cleaning: Carefully clean the oil stains, rust, moisture and other impurities on the parts to be welded of the tube sheet 1 and the head assembly 2 to ensure that the welding area shows metallic luster and avoid affecting the welding quality.

[0065] Assembly: Correctly install the head assembly 2 on the tube sheet 1 to ensure that the concentricity and assembly gap between the two meet the design requirements, and the assembly gap can ensure the fusion quality of the weld;

[0066] Spot welding fixation: Perform spot welding evenly distributed on the circumference to fix the relative positions of the head assembly 2 and the tube sheet 1 to prevent misalignment during the welding process. The number and spacing of spot welds are determined according to factors such as the size and thickness of the tube sheet 1 and the head assembly 2.

[0067] Arc starting: Start the arc from a suitable position, pay attention to the fusion quality at the arc starting point, and avoid defects such as porosity and incomplete penetration.

[0068] Welding rod movement: According to the welding method and weld requirements, adopt a suitable welding rod movement method, such as straight welding rod movement, zigzag welding rod movement or crescent welding rod movement, etc., to ensure that the width and height of the weld are uniform.

[0069] Welding layers: For thicker workpieces, multi-layer and multi-pass welding may be required. After each layer of welding is completed, the welding slag and spatter should be cleaned up, the weld quality should be inspected, and only after passing the inspection can the next layer of welding be carried out.

[0070] Arc termination: When terminating the arc, the crater should be filled to avoid defects such as crater cracks.

[0071] Step 2: Semi-baffle plate and central tube:

[0072] The connection mechanism 3 is used to fix the semi-baffle plate 4 to the central tube 5, preventing it from falling off during the sleeving process, and it is removed after sleeving;

[0073] The semi-baffle plate 4 is accurately installed at the specified position on the central tube 5 and fixed by the connection mechanism 3, ensuring that the semi-baffle plate 4 will not shift or shake during the sleeving process, thereby ensuring the relative position accuracy between components and making the internal structure of the heat exchanger meet the design requirements;

[0074] During the sleeving operation, since the connection between the semi-baffle plate 4 and the central tube 5 is not firm before being fully fixed, the connection mechanism 3 will provide additional fastening force to prevent the semi-baffle plate 4 and the central tube 5 from falling off during the sleeving process;

[0075] The temporary fixing structure for preventing falling off during the sleeving process. After completing the assembly work of sleeving the heat exchanger, the connection mechanism 3 is removed to prevent affecting the relative position of the already assembled semi-baffle plate 4 and central tube 5. At the same time, it prevents leaving too many marks on the components or causing damage to the components;

[0076] Ensure assembly accuracy: During the assembly process of the heat exchanger, the semi-baffle plate needs to be accurately installed at the specified position on the central tube. By fixing with a clamp, it can be ensured that the semi-baffle plate will not shift or shake during the sleeving process, thereby ensuring the relative position accuracy between components and making the internal structure of the heat exchanger meet the design requirements, laying a foundation for subsequent normal operation and good heat transfer performance.

[0077] Prevent sleeving from falling off: During the sleeving operation, since the connection between the semi-baffle plate and the central tube is not firm before the final fixing method such as welding is completed. Especially during the installation of other components or the process of moving and handling the heat exchanger components, under the action of external forces, the semi-baffle plate is very easy to fall off from the central tube, while the clamp can provide additional fastening force to effectively prevent this situation from occurring.

[0078] The clamp is only a temporary fixing measure. After the assembly of the entire heat exchanger and other necessary assembly work are completed, removing the clamp will not affect the relative positions of the assembled semi-baffle and the central tube, nor will it leave excessive marks on the components or cause damage to the components. At the same time, it can provide convenient conditions for subsequent final fixing operations such as welding and expansion jointing, without hindering the implementation of the final fixing method.

[0079] Step 3: Considering the perpendicularity of the central tube 5 and the tube sheet 1, use a plumb line or a level to measure and confirm, and the welding flaw detection is qualified.

[0080] Benchmark point setting: Set one or more benchmark points at appropriate and stable positions around the heat exchanger. The heights of the benchmark points should be kept the same, and it is necessary to ensure that they will not be disturbed and change during the whole measurement process. Use a level to measure and adjust the heights of the benchmark points to make them on the same horizontal plane.

[0081] Initial measurement of the tube sheet: Place the scale vertically on the edge of the tube sheet or at specific measurement points, and use a level to read the scale values on the scale. At different positions of the tube sheet 1, such as the four corners of the edge or more evenly distributed points, conduct multiple measurements, record the readings of each measurement point. By comparing these readings, it can be preliminarily judged whether the tube sheet 1 is horizontal.

[0082] Measurement of the central tube: Place the scale vertically along the outer wall of the central tube 5, and conduct measurements at different height positions of the central tube 5. Similarly, use a level to read the scale values on the scale and record them.

[0083] Adjustment and leveling: According to the measurement results, adjust the tube sheet 1 or the central tube 5. If the tube sheet 1 is not horizontal, it can be adjusted by adding or reducing gaskets at the bottom of the tube sheet 1; if the central tube 5 is not perpendicular, it can be made perpendicular by adjusting the support structure or fixing device of the central tube 5. During the adjustment process, it is necessary to continuously use a level to measure until the tube sheet 1 reaches the horizontal state and the central tube 5 reaches the perpendicular state.

[0084] Preparation work: First, ensure that the level has been calibrated and is in normal working condition. At the same time, prepare the scale for measurement, and place the heat exchanger on a relatively stable foundation to avoid displacement during the measurement process.

[0085] Benchmark point setting: Set one or more benchmark points at appropriate and stable positions around the heat exchanger. The heights of these benchmark points should be kept the same, and it is necessary to ensure that they will not be disturbed and change during the whole measurement process. The heights of the benchmark points can be measured and adjusted using a level to make them on the same horizontal plane.

[0086] Initial measurement of the tube sheet: Vertically place a scale at the edge of the tube sheet or specific measurement points, and use a level to read the scale values on the scale. Conduct multiple measurements at different positions on the tube sheet, such as the four corners of the edge or more evenly distributed points, and record the readings at each measurement point. By comparing these readings, it is possible to preliminarily determine whether the tube sheet is level. If there are significant differences in the readings, it indicates that the tube sheet may not be level and needs to be adjusted.

[0087] Measurement of the central tube: Vertically place a scale along the outer wall of the central tube and conduct measurements at different height positions of the central tube. Similarly, use a level to read the scale values on the scale and record them. If the central tube is vertical, the measurement readings at different height positions should be the same; if there are variations in the readings, it indicates that the central tube is tilted.

[0088] Adjustment and leveling: Based on the measurement results, adjust the tube sheet or the central tube. If the tube sheet is not level, it can be adjusted by adding or reducing shims at the bottom of the tube sheet; if the central tube is not vertical, it can be made vertical by adjusting the support structure or fixing device of the central tube. During the adjustment process, it is necessary to continuously use a level for measurement until the tube sheet reaches a level state and the central tube reaches a vertical state.

[0089] Re-measurement and confirmation: After completing the adjustment, use a level to conduct a comprehensive measurement of the tube sheet and the central tube again. Ensure that the readings at each measurement point meet the requirements, and the levelness of the tube sheet and the verticality of the central tube are within the allowable error range.

[0090] During the entire measurement and leveling process, pay attention to the accuracy and precision of the measurement to avoid measurement errors caused by human factors or environmental factors. At the same time, strictly operate in accordance with relevant operating procedures and safety specifications to ensure the smooth progress of the measurement and adjustment work.

[0091] Step Four: Hoisting beam hoisting:

[0092] Design two clamp 6 structures, fix one end with a hoisting beam bolt, add a counterweight to the other end of the hoisting beam 11, and calculate in advance the weight of the counterweight 13 hoisted on the hoisting beam 11; The clamp 6 is clamped on the straight pipe section of the head assembly 2 and fixed with bolts to play the role of the hoop of the clamp 6;

[0093] Determine the parameters of the hoisting beam 11 and the head assembly 2, clarify the weight and the position of the center of gravity of the hoisting beam 11, the weight of the object to be hoisted, and its hanging position on the hoisting beam 11;

[0094] Measure the distances, measure the distance from the lifting point to the center of gravity of the object to be hoisted, and the distance from the lifting point to the other end of the hoisting beam, the installation position of the counterweight 13;

[0095] Step Five: Pipe support sleeving:

[0096] After the pipe support 7 is completed, it is connected by the lifting beam 11. After the test lifting verifies the counterweight, the outer shell 8 is fixed in the installation area, and manual wire drawing is assisted to ensure that the set is in place;

[0097] During the process of prodding the pipe support 7, a lifting device is used in cooperation. The lifting device lifts the pipe support 7, and the pipe support 7 is lifted and moved through the lifting device to gradually approach the outer shell 8;

[0098] At the same time, arrange a special person to observe the insertion situation of the pipe support and the outer shell 8 behind the pipe support, and timely adjust the direction and strength of prodding and lifting to ensure that the pipe support 7 can be accurately inserted into the outer shell 8;

[0099] When a part of the pipe end of the pipe support 7 is inserted into the outer shell 8, further prodding and fine-tuning can be carried out to insert more of the pipe support 7. Repeat the above operations until the pipe support 7 is completely sleeved into the outer shell 8.

[0100] Place the tube bundle horizontally on a suitable supporting device so that the tube bundle is at a height convenient for operation. Mark the corresponding positions on the tube sheet of the tube bundle with those on the shell for subsequent accurate sleeving.

[0101] The operator uses a prodding rod. The end of the prodding rod can be inserted into specific hole positions on the tube sheet of the tube bundle. Some holes or structures for prodding can be preset in advance. By prodding the prodding rod, the tube bundle generates a certain displacement and rotation in the horizontal direction, and gradually aligns the tube end of the tube bundle with the shell.

[0102] During the process of prodding the tube bundle, a lifting device is used in cooperation to slowly lift and move the tube bundle to gradually approach the shell. At the same time, arrange a special person to observe the insertion situation of the tube bundle inside the shell, and timely adjust the direction and strength of prodding and lifting to ensure that the tube bundle can be accurately inserted into the shell. When a part of the tube end of the tube bundle is inserted into the shell, further prodding and fine-tuning can be carried out to insert more tube ends. During the insertion process, pay attention to avoiding collisions and frictions of the tube ends to prevent damage to the tube ends.

[0103] Specific Embodiment 2: Combine Figure 1 — Figure 8 To illustrate this embodiment, a pick-type sleeving method for a petrochemical shell-and-tube heat exchanger in this embodiment. For the pick-type sleeving method of a petrochemical shell-and-tube heat exchanger, the connecting mechanism 3 adopts a clamp structure, and the semi-baffle 4 and the central tube 5 are disassembled and installed through the clamp structure.

[0104] Specific Embodiment 3: Combine Figure 1 — Figure 8To describe this embodiment, a method for sleeving a petrochemical shell-and-tube heat exchanger in a pick type. The connecting mechanism 3 is of a U-shaped plate structure, and the notch of the connecting mechanism 3 is inserted into the central tube 5. The connecting mechanism 3 is provided with mounting holes, and bolts are inserted into the mounting holes. The bolts pass through the mounting holes on the connecting mechanism 3 and the heat exchange of the semi-baffle 4 to install a set of semi-baffles 4 into the central tube 5.

[0105] The connecting mechanism 3 is inserted into the central tube 5, and the other end overlaps with the semi-baffle 4. The connecting mechanism 3 is provided with hole positions. After aligning the hole positions on the connecting mechanism 3 with the hole positions on the semi-baffle 4, a set of semi-baffles 4 is fixed on the central tube 5 through bolt assemblies to prevent it from falling off during the sleeving process and facilitate removal after sleeving.

[0106] Specific embodiment four: Combining Figure 1 — Figure 8 To describe this embodiment, a method for sleeving a petrochemical shell-and-tube heat exchanger in a pick type. The head assembly 2 has a straight section, and two identical clamps 6 are clamped on the straight section of the head assembly 2. The head assembly 2 is lifted by the two clamps 6.

[0107] The clamp 6 is made of thick steel plate. After the two clamps 6 are aligned, they form a sleeve structure with a notch at the top. This structure can sleeve the straight section on the head assembly 2, so as to lift the head assembly 2.

[0108] Specific embodiment five: Combining Figure 1 — Figure 8 To describe this embodiment, a method for sleeving a petrochemical shell-and-tube heat exchanger in a pick type. The clamp 6 is composed of two C-shaped steel plates, and the two C-shaped steel plates on the clamp 6 are arranged in an overlapping manner.

[0109] For the structure of two clamps 6, one end is fixed by bolts of the hanging beam 11, and a counterweight 13 is added to the other end of the hanging beam 11, which is calculated in advance; the clamp 6 is clamped on the direct pipe section of the head assembly 2 and fixed by bolts to play the role of the hoop of the clamp.

[0110] Specific embodiment six: Combining Figure 1 — Figure 8 To describe this embodiment, a method for sleeving a petrochemical shell-and-tube heat exchanger in a pick type. The arc-shaped surfaces of the two C-shaped steel plates on the clamp 6 are attached to the outer side of the straight section of the head assembly 2, and the two clamps 6 are in a parallel structure.

[0111] Specific embodiment seven: Combining Figure 1 — Figure 8Describe this embodiment, a method for sleeving a pick-type petrochemical shell-and-tube heat exchanger. An upper jacking hole 9 is provided above the clamp, and a lower jacking hole 10 is provided below the clamp;

[0112] A bolt assembly is installed between the upper jacking hole 9 and the lower jacking hole 10, and the two C-shaped steel plates of the clamp 6 are fixedly connected through the bolt assembly.

[0113] The upper jacking hole 9 and the lower jacking hole 10 have the same diameter. By providing the upper jacking hole 9 and the lower jacking hole 10 on the clamp, two adjacent clamps 6 can be fixed, so that the direct current section on the head assembly 2 can be lifted by the two clamps 6.

[0114] Specific embodiment eight: Combine Figure 1 — Figure 8 Describe this embodiment, a method for sleeving a pick-type petrochemical shell-and-tube heat exchanger. After the hole positions of the upper jacking hole 9 of the clamp 6 are aligned with those of the lifting beam 11, they are fixedly connected to the lifting beam 11 through a bolt assembly.

[0115] The lifting beam 11 is integrally rectangular in structure, and the longitudinal section of the lifting beam is I-shaped. A group of rib plates are vertically welded on both sides of the lifting beam 11. The lifting beam 11 is used in cooperation with a crane, and the sleeving 8 can be lifted through the lifting beam 11, facilitating the installation of the sleeving 8.

[0116] Specific embodiment nine: Combine Figure 1 — Figure 8 Describe this embodiment, a method for sleeving a pick-type petrochemical shell-and-tube heat exchanger. A side support plate 12 is installed on the lifting beam 11, and the side support plate 12 on the lifting beam 11 is fixedly connected to the clamp 6.

[0117] The side support plate 12 on the lifting beam 11 is fixedly connected to the lifting beam 11 by welding. Insertion holes for bolts are provided on the side support plate 12. After the upper jacking hole 9 and the lower jacking hole 10 on the clamp 6 are aligned with the hole positions on the side support plate 12, the clamp 6 is fixed on the side support plate 12 of the lifting beam 11 through a bolt assembly, facilitating the installation and disassembly of the clamp 6.

[0118] Specific embodiment ten: Combine Figure 1 — Figure 8 Describe this embodiment, a method for sleeving a pick-type petrochemical shell-and-tube heat exchanger. One end of the lifting beam 11 lifts the head assembly 2, and a counterweight 13 is suspended at the other end of the lifting beam 11.

[0119] After the pipe rack 7 is completed, it is connected by the lifting beam 11. After verifying the counterweight by trial lifting, the outer shell 8 is fixed in the installation area, and manual wire drawing is assisted to ensure that the sleeving is in place;

[0120] During the process of prodding the pipe support 7, a hoisting device is used in cooperation. The hoisting device lifts the pipe support 7, and through the hoisting device, the pipe support 7 is lifted and moved to gradually approach the outer shell 8.

[0121] Meanwhile, arrange a special person to observe the insertion situation of the pipe support and the outer shell behind the pipe support 7, and timely adjust the direction and strength of prodding and hoisting to ensure that the pipe support 7 can be accurately inserted into the outer shell 8.

[0122] When a part of the pipe end of the pipe support 7 is inserted into the outer shell 8, more of the pipe support 7 can be inserted through further prodding and fine-tuning. Repeat the above operations until the pipe support 7 is completely sleeved inside the outer shell 8.

[0123] As mentioned above, it is only a preferred embodiment of the present invention and does not impose any formal restrictions on the present invention. Although the present invention has been disclosed above with the preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art, within the scope of the technical solution of the present invention, can make some changes or modifications to equivalent embodiments by using the disclosed technical content. However, as long as it does not depart from the technical solution content of the present invention, according to the technical essence of the present invention, any simple modification, equivalent replacement, and improvement made to the above embodiments within the spirit and principle of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for installing a petrochemical shell-and-tube heat exchanger in a pick-up manner, characterized in that: The method comprises the following steps: Step 1: Welding of tube sheet and head assembly: The tube sheet (1) and the head assembly (2) are welded in advance and passed the flaw detection to provide a fixed position for subsequent assembly; the head assembly (2) and the tube sheet (1) are connected by a girth weld; The girth weld connection method: Cleaning: Carefully clean the oil, rust, moisture and other impurities on the parts to be welded on the tube sheet (1) and the head assembly (2) to ensure that the welding area has a metallic luster to avoid affecting the welding quality; Assembly: correctly install the head assembly (2) on the tube sheet (1), ensuring that the concentricity and assembly clearance of the two meet the design requirements, and the assembly clearance can ensure the fusion quality of the weld; Spot welding fixation: spot welding is performed evenly distributed on the circumference to fix the relative position of the head assembly (2) and the tube sheet (1) to prevent misalignment during welding. The number and spacing of the spot welding are determined according to factors such as the size and thickness of the tube sheet (1) and the head assembly (2); Step 2: Half baffle and center tube: A connecting mechanism (3) is used to fix the semi-baffle (4) and the central tube (5) to prevent them from falling off during the installation process and to remove them after installation; The semi-baffle (4) is accurately mounted on a designated position of the central tube (5) and fixed by the connecting mechanism (3), ensuring that the semi-baffle (4) will not shift or shake during the assembly process, thereby ensuring the relative position accuracy between the components and making the internal structure of the heat exchanger meet the design requirements; During the installation operation, since the connection between the semi-baffle (4) and the central tube (5) is not firm when they are not completely fixed, the connection mechanism (3) will provide additional fastening force to prevent the semi-baffle (4) and the central tube (5) from falling off during the installation process; The temporary fixing structure is removed during the assembly process. After the assembly of the heat exchanger is completed, the connection mechanism (3) is removed to prevent the relative positions of the assembled semi-baffles (4) and the central tube (5) from being affected and to prevent excessive marks from being left on the components or damage to the components. Step 3: Consider the verticality of the center tube (5) and the tube sheet (1), use a hanging line or a level to measure and confirm that the welding flaw detection is qualified; Benchmark point setting: set one or more benchmark points at suitable and stable positions around the heat exchanger. The height of the benchmark points should be kept consistent and should not be disturbed or changed during the entire measurement process. Use a level to measure and adjust the height of the benchmark points so that they are on the same horizontal plane. For the initial measurement of the tube sheet, a ruler is placed vertically on the edge of the tube sheet or a specific measuring point, and the scale value on the ruler is read using a level. Multiple measurements are performed at different locations of the tube sheet (1), such as the four corners of the edge or more evenly distributed points, and the readings at each measuring point are recorded. By comparing these readings, it can be preliminarily determined whether the tube sheet (1) is level. For the measurement of the central tube, a ruler is placed vertically along the outer wall of the central tube (5), and measurements are performed at different heights of the central tube (5). Similarly, a level is used to read the scale value on the ruler and record it; Adjustment and leveling: according to the measurement results, the tube sheet (1) or the center tube (5) is adjusted. If the tube sheet (1) is not horizontal, it can be adjusted by adding or removing gaskets at the bottom of the tube sheet (1); if the center tube (5) is not vertical, it can be vertical by adjusting the supporting structure or fixing device of the center tube (5). During the adjustment process, it is necessary to continuously measure with a level until the tube sheet (1) reaches a horizontal state and the center tube (5) reaches a vertical state; Step 4: Lifting beam: A two-hoop (6) structure is designed, one end of which is fixed by a suspension beam bolt, and a counterweight is added to the other end of the suspension beam (11), and the weight of the counterweight (13) suspended on the suspension beam (11) is calculated in advance; the hoop (6) is clamped on the direct pipe section of the head assembly (2) and fixed by bolts, playing the role of a hoop of the hoop (6); Determine the parameters of the hanging beam (11) and the end cap assembly (2), clarify the weight of the hanging beam (11) and the position of its center of gravity, the weight of the object to be hung and the hanging position of the object on the hanging beam (11); Measuring distances, measuring the distance from the lifting point to the center of gravity of the object being lifted, and the distance from the lifting point to the other end of the lifting beam, where the counterweight (13) is installed; Step 5: Pipe rack set: After the pipe rack (7) is completed, the hanging beam (11) is used for connection. After the test lifting and verification of the counterweight, the shell (8) is fixed in the installation area, and manual wire drawing is used to assist in ensuring that the set is in place; In the process of moving the pipe rack (7), the lifting equipment is used in conjunction with the pipe rack (7), and the pipe rack (7) is lifted and moved by the lifting equipment so that the pipe rack (7) gradually approaches the shell (8); At the same time, a special person is arranged to observe the insertion of the pipe rack and the shell (8) from behind the pipe rack, and timely adjust the direction and strength of the lifting and hoisting to ensure that the pipe rack (7) can be accurately inserted into the shell (8); After a portion of the pipe ends of the pipe rack (7) are inserted into the housing (8), more pipe racks (7) can be inserted by further stirring and fine-tuning, and the above operations are repeated until the pipe rack (7) is completely inserted into the housing (8).

2. The method for installing a petrochemical shell-and-tube heat exchanger according to claim 1, characterized in that: The connection mechanism (3) adopts a clamp structure, and a group of semi-baffles (4) and the central tube (5) are disassembled and assembled through the clamp structure.

3. The method for installing a petrochemical shell-and-tube heat exchanger according to claim 2, characterized in that: The connecting mechanism (3) is a U-shaped plate structure, and the notch on the connecting mechanism (3) is inserted into the central tube (5). The connecting mechanism (3) is provided with a mounting hole, and a bolt is inserted into the mounting hole. The bolt passes through the mounting hole on the connecting mechanism (3) and the heat exchange on the semi-baffle (4) to install a group of semi-baffles (4) into the central tube (5).

4. The method for installing a petrochemical shell-and-tube heat exchanger according to claim 1, characterized in that: The sealing head assembly (2) has a direct current section, and two clamps (6) with the same structure are clamped on the direct current section of the sealing head assembly (2), and the sealing head assembly (2) is lifted by the two clamps (6).

5. The method for installing a petrochemical shell-and-tube heat exchanger according to claim 4, characterized in that: The clamp (6) is composed of two C-shaped steel plates, and the two C-shaped steel plates on the clamp (6) are arranged in a superimposed manner.

6. The method for installing a petrochemical shell-and-tube heat exchanger according to claim 5, characterized in that: The arc-shaped surfaces of the two C-shaped steel plates on the clamp (6) fit the outer side of the DC section on the head assembly (2), and the two clamps (6) are in a parallel structure.

7. The method for installing a petrochemical shell-and-tube heat exchanger according to claim 6, characterized in that: An upper insertion hole (9) is provided above the clamp, and a lower insertion hole (10) is provided below the clamp; A bolt assembly is installed between the upper insertion hole (9) and the lower insertion hole (10), and the two C-shaped steel plates of the clamp (6) are fixedly connected by the bolt assembly.

8. The method for installing a petrochemical shell-and-tube heat exchanger according to claim 7, characterized in that: After the upper insertion hole (9) of the clamp (6) is aligned with the hole position of the suspension beam (11), it is fixedly connected to the suspension beam (11) via a bolt assembly.

9. The method for installing a petrochemical shell-and-tube heat exchanger according to claim 8, characterized in that: The hanging beam (11) is provided with a side support plate (12), and is fixedly connected to the clamp (6) via the side support plate (12) on the hanging beam (11).

10. The method for installing a petrochemical shell-and-tube heat exchanger according to claim 8, characterized in that: One end of the suspension beam (11) suspends the head assembly (2), and the other end of the suspension beam (11) is suspended with a counterweight (13).

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