Modularized construction method of loop reactor shaped like Chinese character'ri '

Abstract

The invention discloses a modular construction method of a loop reactor shaped like a Chinese character'ri ', and particularly relates to the technical field of loop reactor installation. A modular construction method of a loop reactor shaped like a Chinese character'ri 'comprises the steps that S1, quality control is well conducted on civil engineering foundation positioning formwork installation, civil engineering foundation pouring and foundation retesting, and it is ensured that the foundation deviation is within an allowable value; s2, an assembly site is planned, foundation treatment is implemented, and site preparation is made for ring pipe module assembly; s3, thick steel plates are placed on site according to planning, and profile steel assembly jig frames are prefabricated and installed; the ring pipe barrel is placed on the assembling jig frame, and six ring pipe reactors are assembled at the same time. According to the modular construction method of the loop reactor shaped like the Chinese character'ri ', ground overall framing and modular construction are conducted through the specific assembly jig frame according to the number and structural characteristics of the loop pipes, the traditional mode that in the past, the loop reactor is hoisted in a piece-to-piece mode is broken through, and overall installation of the loop reactor shaped like the Chinese character'ri' is achieved for the first time.

Description

Technical Field

[0001] The present invention relates to the technical field of the installation of a loop reactor, and particularly to a "day-shaped" modular construction method for a loop reactor. Background Art

[0002] With the continuous expansion of the scale of petrochemical plants, shortening the construction period, improving the project quality, reducing the residence time of manpower and machinery on site, eliminating construction safety hazards to the greatest extent, and controlling the project investment cost have become the common goals pursued by all parties in project construction. Statistics show that the "day-shaped" modularization of the loop reactor has shortened the construction period by at least 1 / 2 and greatly reduced the risk of high-altitude operations. The "day-shaped" modular installation of the loop reactor has created favorable conditions for improving the project construction quality, reducing safety accidents, and shortening the construction period.

[0003] The 200,000-ton / year LAO plant has a total of 2 loop reactors (R-241A / B), which are designed by a certain company in Beijing and are class III pressure vessels. The main body of each device consists of 6 reaction tubes Φ508 (outer diameter) / jacket Φ600 (inner diameter) × 42000. These 6 reaction tubes (with jackets) are connected into a circulating whole through large-span elbows. The bottom supports of the pipe sections are fixed on the structural foundation, and the jackets of each pipe are connected by steel profiles to form a frame structure by themselves. The center distance between adjacent pipes of the loop reactor is 4200 mm, and the overall equipment assembly length × width × height is 8400 × 4200 × 47151 (mm). The operating medium in the reaction tube is C2H4, cyclohexane, α-olefin, etc., and the medium in the jacket is cooling water for heat removal. The corresponding design pressures are 5.2 MPa / 1.6 MPa, and the design temperatures are (-40 / 198) °C / 190 °C respectively. The inner pipe material of the reaction tube is SA-672C70-22, and the outer jacket material is Q345R. An axial flow pump is installed at the bottom elbow to force the liquid to circulate in the loop for reaction, and there is a sleeve outside the loop as a jacket for heat dissipation. The inner wall of the loop needs to be polished to Ra ≤ 0.6. The equipment is arranged in the reaction frame of the plant, and the base is installed on the concrete frame foundation 6.8 m high, with high installation accuracy requirements. The two reactors are delivered to the site in the form of 12 cylinders, 10 180° elbows, and 166 connecting beam loose parts for on-site assembly.

[0004] The site of the 200,000-ton / year LAO plant is small. The loop reactor, 11 tower vessels, and 24 storage tanks, as well as the main steel structures of the plant, are all arranged on both sides of the east-west road in the plant area. If constructed in the conventional way, the entire site will be extremely congested, seriously affecting the construction progress. The piecemeal assembly of the loop reactor on-site will also become an obstacle to the construction of the entire plant. The "day-shaped" modular assembly of the loop reactor prefabrication yard has realized the construction mode of "one site, two construction sites" for the loop reactor for the first time, solved the problem of the small site, and at the same time achieved the management goals of "prefabrication factoryization, operation flow, management standardization, and installation integration" for the loop reactor. This method uses a specific assembly jig, and according to the quantity and structural characteristics of the loop pipes, the overall frame is assembled on the ground, and modular construction is carried out, breaking through the traditional mode of piecemeal component assembly and piecemeal hoisting in the past, and realizing the "day-shaped" integral installation of the loop reactor for the first time. This construction method can reduce high-altitude operations, ensure the installation quality, effectively shorten the construction period, reduce the comprehensive cost, and have significant social benefits, and the construction method has great advantages. Summary of the Invention

[0005] In view of the above situation, to overcome the defects of the prior art, the present invention provides a "day-shaped" modular construction method for a loop reactor. Through a specific assembly jig, according to the quantity and structural characteristics of the loop pipes, the overall frame is assembled on the ground, and modular construction is carried out, breaking through the traditional mode of piecemeal component assembly and piecemeal hoisting in the past, and realizing the "day-shaped" integral installation of the loop reactor for the first time.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows: The "day-shaped" modular construction method for a loop reactor includes: S1: Do a good job in quality control for the installation of the civil engineering foundation positioning template, the pouring of the civil engineering foundation, and the re-measurement of the foundation to ensure that the foundation deviation is within the allowable value; S2: Plan the assembly site and implement foundation treatment to prepare the site for the assembly of the loop module; S3: Place thick steel plates on-site according to the plan and prefabricate and install the steel section assembly jig; Place the loop reactor barrel on the assembly jig, and assemble 6 loop reactors of a single unit at the same time; S4: Carry out labor protection and heat preservation and cold insulation construction; S5: Transport and hoist the "day-shaped" loop reactor integrally into place.

[0007] Preferably, the jig is made of thick steel plates and H-shaped steel to make a double-layer portal frame for the assembly of the loop pipes.

[0008] Preferably, the construction process for assembling the frame of a single loop reactor includes the following steps: (1) After the foundation treatment, lay 12 steel plates with a size of 12000×2000 mm flat, measure the elevation of the upper surface of the 12 steel plates, take the highest point as the reference, adjust the levelness and elevation of the upper surface of the 12 steel plates, and place the jig on the steel plates; Measure the elevation of the top surface of the two layers of steel sections of the 6 jigs; (2) After the bottom frame crossbeam is in place, measured and adjusted, the three cylinders R4, R5 and R6 are placed in sequence, and the spacing between the three cylinders is initially adjusted to about 4.2m by means of the positioning block; after the top frame crossbeam is installed, the three cylinders R1, R2 and R3 are placed in place in sequence, and the spacing is adjusted to 4.2m; when the six cylinders are unloaded and placed on the frame, the coplanarity of the flanges at the bottom of the cylinders needs to be measured, and the coplanarity deviation of the six flanges at the bottom of the cylinders needs to be controlled within 0-2mm through pre-assembly of elbows; (3) Before the tire frame and the six cylinders are in place, three sets of double-row scaffolding are set up at intervals of 4.2m. Each set of scaffolding is 45m long, 1m wide and 8m high, and the springboard is 5.8m from the ground. The three sets of scaffolding are required for the subsequent installation of the upper tire frame beams and the R1, R2 and R3 cylinders; (4) First install the three crossbeams between the cylinders, connect the elbows to the bottom flange of the cylinder, and fix the three 180° upper elbows A1, A3, and A5 to the top flange of the cylinder. Ensure the cylinder spacing by connecting the upper and lower elbows to the upper and lower flanges of the cylinder. After the connection is completed, measure the module size diagonally; (5) Connect the beams between R4 and R5, and between R5 and R6. After completing the connection of the first layer of cylinder beams, connect the beams between R1 and R6, R2 and R5, and R3 and R4. Then, use bolts to connect the beams between R1 and R2, and between R2 and R3. After all beams are connected, re-measure the diagonal size of the module. (6) After the size is correct, a temporary connecting beam is welded between two adjacent skirts to reinforce the cylinder. Each connection node is welded. Symmetrical welding and step-by-step skip welding are used. The welding sequence is: 1) R4, R5, R6 three cross beams between cylinders, 2) The crossbeam between R2 and R5, 3) Crossbeams between R3 and R4, R1 and R6, 4) R1, R2, R3 three cross beams between cylinders; (7) Reinforcement of the hanging point; 1) The bottom lifting point is reinforced by connecting and reinforcing with steel sections to form a relatively stable structure at the tail to prevent deformation during lifting. The tail can be removed after being hoisted into place; 2) Strengthen the top hanging point by using Φ219×8 seamless carbon steel pipe to connect the connecting beam at the hanging ear position with the lower layer. Connect the beams for connection reinforcement; (8) Labor protection and thermal insulation installation 1) During the installation of the cylinder body and cross beams, prefabricate the inclined ladders in advance. After the installation of 77 cross beams of a single reactor is completed, cut the column of the falsework at a height of 3.5 meters from the ground, and use a crane to cooperate in removing the cross beam of the top falsework. Hoist the 11th-floor inclined ladder into place through the gap of the corresponding cross beam; after the acceptance of labor protection and cross beam anti-corrosion, carry out the anti-corrosion and heat preservation process. Except for the reserved part at the bottom falsework, the heat preservation of the remaining parts is completed on the ground, and the heat preservation at the bottom falsework is completed when the falsework is hoisted 1000 mm on site. Part of the bottom falsework is retained as the support for the loop pipe.

[0009] 2) There are 3 layers of combined platforms between the two reactors. Two [20A, one [10, three [16A, two I10 and steel gratings belonging to the combined platform can be welded and installed between the four cylinder bodies of the two reactors R2, R3, R4, and R5 respectively on the ground.

[0010] Preferably, the S5 includes the following steps: (1) Unloading the vehicle: For the hoisting and unloading of 2 loop reactors, adopt the hoisting process of double-vehicle lifting and translation method. Use 1000-ton and 400-ton crawler cranes to lift the head and tail of the equipment respectively. First, the two cranes horizontally lift the equipment off the supporting cross beam, the axis vehicle transports the supporting cross beam away from the bottom of the equipment, and then horizontally lift and hoist the equipment to carry out supplementary work such as cold insulation; (2) Lifting and positioning For the lifting and positioning of 2 loop reactors, adopt the hoisting process of single-main-lift and delivery method. Use a 1000-ton crawler crane as the main hoisting crane to lift the head of the equipment, and use a 400-ton crawler crane as the tailing crane to lift the tail of the equipment. First, the two cranes horizontally lift the equipment, then the main crane is responsible for lifting the head of the equipment, and the tailing crane is responsible for delivering the tail of the equipment forward. The two cranes cooperate to gradually transition the equipment from a horizontal state to an upright state. After the equipment reaches the upright state, the tailing crane disengages the hook, the main crane rotates to hoist the equipment above the foundation, and then the main crane lowers the hook to install the equipment on the foundation. After positioning and alignment, fix the anchor bolts and remove the rigging to complete the hoisting work; (3) Placing shims Place 2 groups of shims at the edge of each anchor bolt on the top of the foundation. Each group consists of one flat and two inclined shims, and they are placed under the rib plate; there are 6 supports for each equipment, and 24 groups of shims are placed for each support; level the elevation of the upper surface of all shim groups within ±1 mm, and tighten the anchor bolts after positioning; (4) Inserting and tightening the skirt support anchor bolts Six cylinders of each loop reactor need to pass through six Φ1160mm holes reserved in the frame, and 72 M64×2260mm anchor bolts of six skirt supports need to be accurately positioned in place. When installing the anchor bolts, a movable pulley should be suspended on the upper connecting beam using a rope sling, and the bolts should be lifted using a rope tool. Two people should cooperate to insert the bolts into the skirt support and the foundation reserved holes as a whole.

[0011] Compared with the prior art, the present invention has the following beneficial effects: (1) Through a specific assembly jig, the present method performs overall frame assembly on the ground according to the number and structural characteristics of the loop reactors, with modular construction, breaking through the traditional mode of piece-by-piece assembly and piece-by-piece hoisting, and realizing the "day-shaped" overall installation of the loop reactor for the first time.

[0012] (2) This construction method can reduce high-altitude operations, ensure the installation quality, effectively shorten the construction period, reduce the comprehensive cost, and have significant social benefits, with great superiority in the construction method. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the "day-shaped" assembly of the loop reactor; Figure 2 It is a machining drawing of the positioning template; Figure 3 It is a schematic diagram of the loop reactor assembly site; Figure 4 It is a schematic diagram of the lower layer jig; Figure 5 It is a schematic diagram of the overall jig; Figure 6 It is a schematic diagram of the placement of the lower layer cylinders; Figure 7 It is a schematic diagram of the layered placement position of the cylinders on the jig; Figure 8 It is a schematic diagram of the relative dimensions of the loop reactor skirt support; Figure 9 It is a schematic diagram of the diagonal measurement; Figure 10 It is a schematic diagram of the reinforcement of the bottom skirt support; Figure 11 It is a schematic diagram of the reinforcement of the upper lifting lug; Figure 12 It is a schematic diagram of the overall frame assembly; Figure 13 It is an assembly drawing of the loop reactor. DETAILED DESCRIPTION OF THE INVENTION

[0014] The following embodiments further illustrate the present invention, and the embodiments of the present invention include but are not limited to the following embodiments.

[0015] Basic Construction Preparation Requirements for the loop reactor foundation: (1) The inside of the bolt sleeves used for positioning in the foundation must be cleaned thoroughly.

[0016] (2) After grouting, the elevation of the upper surface of the adjusting plate on the foundation should be ensured to be 6800 mm.

[0017] (3) The levelness of the upper surface of the adjusting plate on the foundation should not be greater than ±1.0 mm within the outer diameter range of the adjusting plate.

[0018] Key control points for the construction of the annular pipe foundation (1) Strictly control the quality of each process from foundation positioning and setting out, foundation trench excavation, steel bar binding, formwork support, positioning formwork installation, concrete pouring, etc., to ensure that the foundation deviation meets the installation requirements of the annular pipe reactor.

[0019] (2) Make the positioning formwork through mechanical drawing and machining manufacturing to ensure that the geometric dimensions of the positioning formwork should be consistent with the skirt support spacing, bolt hole spacing, and various relative dimensions of the annular pipe reactor.

[0020] (3) The installation accuracy of the foundation positioning formwork is the prerequisite for the smooth placement of the annular pipe reactor. The positioning formwork is equipped with spacer steel. Assemble the formwork strictly according to the drawings on site. After assembly, measure the spacing of each bolt hole of the positioning formwork. When installing the positioning formwork, pay attention to the distance between the positioning formworks, which should be controlled within the range of 4200 ± 5 m. During the foundation pouring and vibration process, assign special personnel to measure the distance between the two formworks at all times. If any change is found, adjust it in time; only after confirming that all the levelness and spacing are qualified can the next process be carried out.

[0021] (4) Before equipment installation, conduct handover acceptance of the foundation.

[0022] The foundation should have technical documents such as geometric dimension measurement reports.

[0023] There should be elevation reference lines and longitudinal and transverse axes on the foundation; There should be no defects such as cracks, honeycombing, cavities, exposed steel bars, etc. in the foundation concrete; Check whether the dimensions of the foundation meet the requirements according to the civil construction drawings and the foundation drawings provided by the manufacturer. The specific requirements are shown in Table 1.

[0024] Clean the inside of each bolt hole sleeve of the positioning formwork in the foundation thoroughly, and there should be no blockage such as soil, construction waste, foam, etc.; after passing the acceptance, handle the acceptance and handover records. Table 1 Allowable deviations of foundation dimensions and positions Unit: mm

[0025] Acceptance, counting, inspection and storage of the annular pipe loose parts upon arrival (1) The equipment and accessories delivered for installation must meet the design requirements and be accompanied by technical documents such as factory inspection certificates and installation instructions.

[0026] (2) Inspection and counting should be carried out with the participation of relevant personnel, in accordance with the packing list and drawings, according to the following items, and the "unpacking acceptance record" should be filled in. It includes the following contents: 1) Number, number of boxes and packaging of the components of the ring pipe; 2) Name, type, model and specification of the components of the annular pipe; 3) The dimensions and orifice orientation of the annular tube components; 4) Missing parts, damage, deformation and corrosion status.

[0027] (3) All parts of the annular tube reactor should be directly transported to the annular tube reactor assembly site, and attention should be paid to the placement direction to reduce secondary handling; the flange area should be kept closed; the paint on the body that has fallen off or been damaged should be repainted; parts that are not yet installed should be kept in a special place.

[0028] (4) Before assembly, the installation reference line and positioning reference mark should be marked on the tire frame according to the design drawings or technical documents. For the upper and lower cylinders that are related to each other, a common reference should also be determined according to the related requirements.

[0029] (5) Before installation, the annular tube body, large elbow, other accessories and anchor bolts should be inspected to ensure that there is no damage or rust; the orientation mark, center of gravity mark and hanging point of the annular tube body should be checked.

[0030] (6) Before installation, the thickness, spectrum and other tests of the annular tube reactor body should be carried out to ensure that the material of the body is qualified.

[0031] On-site assembly site layout The annular reactor assembly site is located outside the device area. The site is 50 meters wide and 81 meters long, with a total area of ​​about 4,050 square meters. The area is closed as a whole, and fences are built around it. The site is pre-filled, leveled, compacted, and poured with concrete to achieve basic bearing capacity. The assembly site must be able to meet the requirements of the on-site lifting radius and transportation turning radius.

[0032] Preparation of pre-assembled tire frame Design Technical Specifications The technical requirements for the assembly of loop reactors are as follows: (1) After installation, the verticality tolerance of the cylinder is ±5 mm at the highest point of the cylinder.

[0033] (2) The bottom surfaces of the cylinder supports should be in the same plane, and the coplanarity tolerance should be 0 to 2 mm.

[0034] (3) The tolerance for the distance between the center lines of each pair of cylinders is ±5 mm at the end flanges and supports, and ±7 mm at other locations.

[0035] (4)The coplanarity tolerance of the sealing surface of the bottom flange of the cylinder body is ±2 mm, and the parallelism tolerance is ±1.0 mm within the outer diameter of the flange.

[0036] Fabrication of the jig Since high-precision ground assembly of the annular pipe needs to be ensured, the fabrication precision of the jig is very crucial. Double-layer gantry frames made of thick steel plates and H-shaped steel are used for the assembly of the annular pipe. The elevation of the load-bearing beam in the middle of the gantry frame is adjusted accordingly according to the outer diameter of different sections of the annular pipe to ensure the straightness of the cylinder body.

[0037] The fabrication of the assembled support should meet the following requirements: The main body of the jig uses HM544×300×11×15 mm and HM488×300×11×18 mm steel sections. The bottom uses a δ = 25 mm thick (700×450 mm) steel plate as the column base plate. HM544×300×11×15 mm is used as the column. Two brackets are welded on the wing plate of each column. The elevation of the top surface of the brackets is 1.4 m and 5.6 m. The column size is 7 m high. HM488×300×11×18 mm steel section is used as the cross beam. The size is 9.5 m long. The middle cross beam is divided into two layers. The bottom layer of steel section is placed on the 1.4 m bracket and welded and fixed. The net clearance from the bottom to the ground is 1.4 m (the jig numbers are 1-6. The jig at the skirt support is No. 1, and the jig at the top elbow is No. 6. The bottom surface elevations of the cross beams of the 1-6 jigs are +1.4 m, +1.422 m, +1.446 m, +1.446 m, +1.45 m, +1.45 m in sequence). Before the arrival of the equipment cylinder body, the placement position of the cylinder body is marked on the bottom layer of steel section in advance by setting out lines. The distance between the two layers of cross beams is 4.2 m. The top cross beam is welded after the three cylinders below are in place. The jig uses φ219×7 mm steel pipes as diagonal braces for stability. HM300×200×8×12 mm steel sections are used to connect and fix between the two gantry frames. The placement positions of the jigs correspond to the cylinder body elevations: +6150 mm, +11150 mm, +21450 mm, +26450 mm, +37850 mm, +42150 mm. Since the span of the jig is nearly 10 m long and considering the weight of a single pipe of the annular pipe reactor is 40 T, in order to prevent the cross beam from deforming after the pipe is in place, HM300×200×8×12 mm steel sections are added as support beams between the first layer and the ground and between the first layer and the top cross beam. After the fabrication of the jig is completed, manual mechanical rust removal is carried out. The rust removal grade is st2.0. Anticorrosive paint is applied. The anticorrosive coating uses 1 coat of epoxy zinc-rich primer and 1 coat of aliphatic polyurethane topcoat. To prevent the cylinder body from sagging, 5 30T thin hydraulic jacks are prepared and used in combination with brackets to support the cylinder body.

[0038] Technical requirements for annular pipe assembly The six cylinders of a single reactor are assembled as a whole for hoisting. The two reactors are hoisted and positioned in two times. After positioning, there are seven layers of cross beams (14 in total), three intermediate combined channels, and six connecting pipes between the two reactors, which need to be installed after the equipment is hoisted and positioned. The 44.69-meter platform can be installed on the ground for the platforms in the middle areas of R1, R2, R5, and R6, and the rest are installed through pre-erected scaffolding after the equipment is positioned.

[0039] During the assembly process of the loop reactor components, a torque wrench is used. When positioning, the bolts are initially tightened, and finally tightened before the connecting beam is welded.

[0040] During the entire assembly process, the expansion joint protection cover shall not be disassembled; the sealing surfaces of the bottom flanges of the cylinders shall be in the same plane, and the allowable value of the coplanarity deviation is ±2 mm. The center line distance between two cylinders is ±5 mm except at the end flanges and skirt supports, and ±7 mm for the rest of the parts.

[0041] The measurement list during the assembly process is shown in Table 2 Table 2

[0042] During ground assembly, angle steels can be welded at the cylinder bracket legs (in two directions, one at the upper and lower parts of the cylinder respectively). (The scale is drawn in advance. When drawing the scale, it should be noted that the thickness of the cylinder sleeves is different, and the length of the angle steel extending out is not more than twice the thickness of the heat insulation layer) and used as inspection scales. After the equipment is positioned, the verticality of the equipment can be inspected according to the inspection scales. The allowable tolerance of the cylinder verticality is ±5 mm at the highest point.

[0043] The B1, B2, and A6 nozzles connected to the lower parts of cylinders R1 and R6 are connected to the inlets and outlets of the axial flow pumps P241A / B. This section is welded on-site during the equipment positioning and pipe fitting with the pumps.

[0044] Construction process of the frame assembly of a single loop reactor Assembly process: (1) After the foundation treatment, 12 steel plates of 12000×2000 mm (δ = 25 mm) are laid flat, and the elevation of the upper surfaces of the 12 steel plates is measured. Taking the highest point as the reference, adjust the levelness and elevation of the upper surfaces of the 12 steel plates (the top elevation is controlled within 1 mm, and thin steel plates can be added at the low points for adjustment), and place the jig on the steel plates; measure the elevation of the top surfaces of the two layers of section steels of the six jigs (the elevation differences of No. 1-6 are controlled within 0, +30 mm, +46 mm, +46 mm, +50 mm, +50 mm. If there are errors, local fine adjustment and leveling work can be carried out using thin steel plates). Since the cylinder wall thickness gradually decreases from bottom to top, the center of the cylinder is leveled by increasing the top elevations of the six groups of jigs to facilitate subsequent measurement and assembly.

[0045] (2) After the bottom frame crossbeam is in place, measured and adjusted, the three cylinders R4, R5 and R6 are placed in sequence, and the spacing between the three cylinders is initially adjusted to about 4.2m by means of the positioning block; after the top frame crossbeam is installed, the three cylinders R1, R2 and R3 are put in place in sequence, and the spacing is adjusted to 4.2m; when the six cylinders are unloaded and placed on the frame, the coplanarity of the lower flanges of the cylinders needs to be measured, and the coplanarity deviation of the six lower flanges of the cylinders needs to be controlled within 0 to 2mm through pre-assembly of elbows.

[0046] (3) Before the tire frame and the six cylinders are in place, three sets of double-row scaffolding are set up at intervals of 4.2 m. Each set of scaffolding is 45 m long, 1 m wide and 8 m high, with the springboard 5.8 m from the ground (the upper surface of the R1 cylinder is 7.3 m from the ground). The three sets of scaffolding are required for the subsequent installation of the upper tire frame beams and the R1, R2 and R3 cylinders.

[0047] (4) Prioritize the installation of three crossbeams between cylinders (install the 1st, 6th and 11th beams between every two cylinders, connected only by bolts), connect the elbow to the bottom flange of the cylinder, and fix the three 180° upper elbows A1, A3 and A5 to the top flange of the cylinder. Ensure the cylinder spacing by connecting the upper elbow and the lower elbow to the upper and lower flanges of the cylinder. After the connection is completed, measure the module size diagonally; (5) Connect the cross beams between R4 and R5, R5 and R6 (only use bolts to connect first). After completing the connection of the first layer of cylinder cross beams, connect the cross beams between R1 and R6, R2 and R5, R3 and R4. Finally, use bolts to connect the cross beams between R1 and R2, R2 and R3. After all the cross beams are connected, re-measure the module diagonal dimensions (R1, R2, R5, R6 and R3, R4, R5, R6, R1, R6, R3, R4 three groups of diagonal dimensions need to be measured). (6) After the dimensions are correct, weld the temporary connecting beams between the two adjacent skirts to reinforce the cylinder, and perform the Welding: Welding adopts symmetrical welding and step-by-step jump welding (step-by-step jump welding is performed with one beam interval). The welding sequence is: 1) R4, R5, R6 three cross beams between cylinders 2) Crossbeam between R2 and R5 3) Crossbeams between R3 and R4, R1 and R6 4) R1, R2, R3 three cross beams between cylinders (7) Reinforcement of the lifting point 1) The bottom lifting point is reinforced by connecting and reinforcing with steel sections to form a relatively stable structure at the tail to prevent deformation during lifting. Figure 10 Bottom skirt reinforcement diagram).

[0048] 2) Reinforce the top suspension points. Connect the connecting beam at the lug position and the lower connecting beam with a seamless carbon steel pipe of Φ219×8 for reinforcement ( ). Figure 11 Schematic diagram of the upper lug reinforcement).

[0049] (8) Labor protection and thermal insulation installation 1) During the installation of the cylinder body and cross beams, prefabricate the inclined ladder in advance (the guardrail is welded after the inclined ladder is in place). After the installation of 77 cross beams of a single reactor is completed, cut the column of the falsework at a height of 3.5 meters from the ground (the height can be adjusted on site to ensure that it does not affect the installation of the inclined ladder). Use a crane to cooperate in removing the top falsework cross beam. Hoist the 11th floor inclined ladder into place through the gap of the corresponding cross beam. After the labor protection and the anti-corrosion acceptance of the cross beam are completed, carry out the anti-corrosion and thermal insulation process. Except for the reservation at the bottom falsework, the thermal insulation of the rest of the parts is completed on the ground. The thermal insulation at the bottom falsework is completed when the on-site hoisting is about 1000 mm. To ensure construction safety, part of the bottom falsework is retained as the support for the loop pipe to prevent hoisting accidents.

[0050] 2) There are 3 layers of combined platforms between the two reactors. The two [20A, one [10, three [16A, two I10 and steel gratings belonging to the combined platform can be welded and installed between the four cylinder bodies of the two reactors R2, R3, R4, R5 on the ground respectively.

[0051] After the overall frame of the transportation, hoisting and installation is accepted as qualified, use the axle line vehicle to transport it to the site. The axle line vehicle adopts 4 longitudinal columns with 28 axles + 2 PPU (two power heads). The axle line vehicle can drive directly under the loop pipe assembly falsework, rise through its suspension system and contact the 6 cross beams of the falsework to reach the load-bearing state, and then horizontal road transportation can be carried out.

[0052] Hoisting and installation (1) Unloading Use the hoisting process of double vehicle lifting and translation method to unload and hoist the 2 loop pipe reactors (1090-R-241A / B). Use a 1000-ton and a 400-ton crawler crane to lift the head and tail of the equipment respectively. First, the two cranes horizontally lift the equipment off the support cross beam. The transportation support cross beam of the axle line vehicle drives away from the bottom of the equipment, and then the equipment is horizontally lifted and hoisted to carry out supplementary work such as cold insulation.

[0053] (2) In-place hoisting Two annular tube reactors (1090-R-241A / B) were hoisted into place using a single-host lifting and delivery method. A 1,000-ton crawler crane was used as the main crane to lift the head of the equipment, and a 400-ton crawler crane was used as the tail crane to lift the tail of the equipment. The two cranes first lifted the equipment horizontally, and then the main crane was responsible for lifting the head of the equipment, and the tail crane was responsible for delivering the tail of the equipment forward. The two cranes cooperated to gradually transition the equipment from a horizontal state to an upright state. After the equipment reached the upright state, the tail crane was unhooked, and the main crane rotated to hoist the equipment above the foundation. Then the main crane dropped the hook to install the equipment on the foundation. After it was in place and aligned, the anchor bolts were fixed, the rigging was removed, and the hoisting work was completed.

[0054] (3) Placement of shims Place 2 sets of shims (one flat and two inclined) beside each anchor bolt at the top of the foundation, and place them under the rib plate. Each equipment has 6 supports, and each support has 24 sets of shims. The specifications of the shims are shown in Table 3. Level all the shim groups to within ±1mm of the upper surface elevation, and tighten the anchor bolts after they are in place. The verticality of the annular tube reactor can be adjusted by adjusting the shim group, and the verticality can be re-measured by the pre-welded ruler.

[0055]

[0056] (4) Tighten the skirt base anchor bolts into place. The six cylinders of each ring tube need to pass through the six Φ1160mm holes reserved in the frame, and the 72 M64×2260mm anchor bolts of the six skirts need to be accurately positioned. When installing the anchor bolts, a rope buckle needs to be used to hang a movable pulley on the upper connecting beam, and the bolts need to be lifted with ropes. Two people need to work together to insert the bolts as a whole into the reserved holes of the skirt and foundation.

[0057] The ring pipe skirt and anchor bolts constructed by this method are precisely positioned, reflecting the superiority of ground assembly in quality assurance.

Claims

1. The "day-shaped" modular construction method for a loop reactor is characterized in that Including: S1: Conduct quality control over the installation of civil engineering foundation positioning templates, the casting of civil engineering foundations, and the re-measurement of foundations to ensure that the foundation deviation is within the allowable value. S2: Plan the assembly site, carry out foundation treatment, and prepare the site for the assembly of the loop pipe module. S3: Place thick steel plates on site according to the plan, prefabricate and install the steel section assembly jig; place the loop pipe cylinder on the assembly jig, and assemble 6 loop pipe reactors simultaneously for each unit. S4: Carry out labor protection and thermal insulation and cold insulation construction. S5: Transport and hoist the loop pipe reactor as a whole in the shape of a "day character" into place.

2. The "day-shaped" modular construction method of the loop reactor according to claim 1, characterized in that, The jig is made of thick steel plates and H-shaped steel to form a double-layer portal frame for the assembly of the loop pipe.

3. The "day-shaped" modular construction method of the loop reactor according to claim 1, characterized in that The construction process of assembling the frame of each loop pipe reactor includes the following steps: (1) After the foundation treatment, lay 12 steel plates with dimensions of 12000×2000 mm flat, measure the elevation of the upper surfaces of the 12 steel plates, take the highest point as the benchmark, adjust the levelness and elevation of the upper surfaces of the 12 steel plates, and place the jig on the steel plates; measure the elevation of the top surfaces of the two layers of steel sections of the 6 jigs. (2) After the bottom jig crossbeam is in place and measured and adjusted, place the three cylinders R4, R5, and R6 in sequence, and initially adjust the distance between the three cylinders to about 4.2 m by relying on the positioning blocks; after installing the top jig crossbeam, place the three cylinders R1, R2, and R3 in sequence and adjust the distance to 4.2 m; when the six cylinders are unloaded and placed on the jig, it is necessary to measure the coplanarity of the lower flanges of the cylinders, and ensure that the coplanarity deviation of the six lower flanges of the cylinders is controlled within 0 - 2 mm through the pre-assembly of the elbows. (3) Before the jig and the six cylinders are in place, set up three groups of double-row scaffolds at intervals of 4.2 m. Each group of scaffolds is 45 meters long, 1 meter wide, and 8 meters high. The gangplank is 5.8 m from the ground. The subsequent installation work of the top jig crossbeam and the cylinders R1, R2, and R3 all requires the use of the three groups of double-row scaffolds. (4) First, install the three crossbeams between the cylinders, connect the elbows to the bottom flanges of the cylinders, and connect and fix the three 180° upper elbows A1, A3, and A5 to the top flanges of the cylinders. Ensure the cylinder spacing by connecting the upper and lower elbows to the upper and lower flanges of the cylinders. After the connection is completed, measure the module dimensions diagonally. (5) Connect the crossbeams between R4 and R5, and between R5 and R6. After completing the connection of the first-layer cylinder crossbeams, connect the crossbeams between R1 and R6, R2 and R5, and R3 and R4. Then connect the crossbeams between R1 and R2, and between R2 and R3 with bolts. After all the crossbeams are connected, re-measure the diagonal dimensions of the module. (6) After the dimensions are correct, weld temporary connection beams between adjacent skirt seats to reinforce the cylinders, and weld each connection node. The welding adopts symmetric welding and step-by-step skip welding. The welding sequence is: 1) The crossbeams between the three cylinders R4, R5, and R6, 2) The crossbeam between R2 and R5, 3) The crossbeams between R3 and R4, and between R1 and R6, 4) The crossbeams between the three cylinders R1, R2, and R3; (7) Reinforce the hoisting point positions; 1) Reinforce the bottom hoisting point position. Use steel sections to connect and reinforce it to form a relatively stable structure at the tail to prevent the tail from deforming during hoisting, and then remove it after hoisting and positioning. 2) Reinforce the top hoisting point. Use seamless carbon steel pipes with a diameter of Φ219×8 to connect the connecting beam at the hoisting ear position to the lower connecting beam for reinforcement. ​ (8) Labor protection and thermal insulation installation 1) During the installation of the cylinder and beams, the inclined ladder is prefabricated in advance. After the installation of 77 beams of a single reactor is completed, the frame columns are cut off from 3.5 meters above the ground, and the crane is used to dismantle the top frame beams. The 11-layer inclined ladder is hoisted into place through the corresponding beam gaps; after the labor protection and beam anti-corrosion acceptance are completed, the anti-corrosion and heat preservation process is carried out. Except for the reservation at the bottom frame, the rest of the parts are insulated on the ground. The insulation of the bottom frame is completed when it is hoisted 1000mm on site, and the bottom frame is reserved as a ring pipe support; 2) There is a three-layer joint platform between the two reactors, and two [20A, one [10, three [16A, two I10 and steel grilles belonging to the joint platform between the four cylinders of the two reactors R2, R3, R4 and R5 can be welded and installed on the ground.

4. The "day-shaped" modular construction method of the loop reactor according to claim 1, characterized in that, The S5 includes the following steps: (1) Unloading: The two annular tube reactors were hoisted and unloaded using a double-car lifting and translation method. A 1,000-ton and a 400-ton crawler crane were used to lift the head and tail of the equipment respectively. The two cranes first lifted the equipment horizontally away from the supporting beams, and the axis truck transported the supporting beams away from the bottom of the equipment. Then the equipment was lifted horizontally to carry out cold insulation and other filling work. (2) Hoisting in place The two annular reactors were hoisted into place using a single-host lifting and delivery method. A 1,000-ton crawler crane was used as the main crane to lift the head of the equipment, and a 400-ton crawler crane was used as the tail crane to lift the tail of the equipment. The two cranes first lifted the equipment horizontally, and then the main crane was responsible for lifting the head of the equipment, and the tail crane was responsible for delivering the tail of the equipment forward. The two cranes cooperated to gradually transition the equipment from a horizontal state to an upright state. After the equipment reached the upright state, the tail crane was unhooked, and the main crane was rotated to hoist the equipment above the foundation. Then the main crane dropped the hook to install the equipment on the foundation. After alignment, the anchor bolts were fixed, and the rigging was removed to complete the hoisting work. (3) Placement of shims Place 2 sets of shims beside each anchor bolt at the top of the foundation, one flat and two oblique, under the rib plate; each device has 6 supports, and 24 sets of shims are placed on each support; level all shim sets to within ±1 mm of the upper surface elevation, and tighten the anchor bolts after they are in place; (4) Tighten the skirt base anchor bolts into place. The six cylinders of each ring tube need to pass through the six Φ1160mm holes reserved in the frame, and the 72 M64×2260mm anchor bolts of the six skirts need to be accurately positioned. When installing the anchor bolts, a rope buckle needs to be used to hang a movable pulley on the upper connecting beam, and the bolts need to be lifted with a rope. Two people need to work together to insert the bolts as a whole into the reserved holes of the skirt and foundation.

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