Construction Technology Nangang 50000 Dry Gas Storage Tank Production and Installation Technology Wang Pingping, Zhang Ruhai China Ten Metallurgical Construction Co., Ltd., Huangshi, Hubei 435004 Abstract Nangang Converter 50000 plus lower gas cabinet Nominal volume 50000 埤Cylinder cylindrical, inner diameter The height of 46585 is 38100, the top cover is spherical, and the total height is 45550. The total consumption of gas in the gas cabinet. Based on the actual construction experience and relevant regulations on the site, this paper briefly introduces the cabinets of the domestic steel emerging and universal meters. According to the characteristics of the gas cabinets, starting from the process sequence and construction points of the gas cabinet main construction, the author's point of experience is discussed.
21.1 Basic acceptance, 1904 call the quality of the construction of the foundation surface will directly affect the appearance quality and empty drum phenomenon of the gas cabinet floor. In the actual construction inspection, the spherical foundation is contoured every 31 in the diameter direction, and the reference point is set every 31 along the circumferential direction on the same high line. The bottom plate of each adjacent reference point is directly laid on the spherical base with a spherical radius of 3 sounds. 7145382 è¿…ç¦ 979 high allowable error between the two main columns of the standard allowable error 21.2 bottom plate assembly 700 æ°“ middle spherical part is the middle plate, thickness 4.5 outer edge is the edge plate, thickness 6 basic inspection after the start of the bottom plate assembly, before assembly The anti-corrosion coating should be applied below, and the bottom edge of each bottom plate is not brushed within 50 limits. Most of the size rules of the medium plate can be directly laid with raw materials, no need to cut and cut the material, and the edges are all curved. In actual construction, the 1500 and 6000 plates are cut with two edge plates to save the most material. The intermediate frame and the edge plate are each provided with a lap joint, and the lap length is not less than 30, wherein the length of the middle plate at the lap joint with the arcuate edge plate is appropriately enlarged by 20 to offset the welding shrinkage of the middle plate. 2. The lap joint of the board should be cut at the uppermost floor, and the weld of the edge of the edge plate should be spliced ​​with the lining plate according to the design requirements. The gap of the butt joint is 5±DmnJ, the first shop is assembled, the pain is caused by, and the middle plate is 4 Lay from top to bottom, then lay the middle plate in 4 quadrants from top to bottom, and finally lay the edge plate. After assembly, fix the lap joint with temporary fixture or spot welding.
The bottom plate is laid on the spherical foundation without any anchoring point, and the area is large and the thickness is thin. Therefore, how to minimize the welding deformation of the bottom plate becomes the key point of the construction quality of the bottom plate is also difficult, and the piston plate will be used in the later construction of the piston plate. Have an impact. In the actual construction, we started from the welding sequence and method and combined with the welding experience of the welder, and obtained a better welding method using the intermittent welding and the back-welding method. The length of the intermittent weld is about l50mm, the spacing is 3 (1), and the rest is to be welded to the next pass after the first weld is completed. Weld No. 2.12 Long welds are temporarily not welded, temporarily fixed by spot welding or fixtures. The purpose is to disperse and release the stress of the middle plate as much as possible. Next, the four welders will lengthen the 4th in each quadrant from top to bottom. After the weld is welded, the welding is intermittent welding. After the welding, the 12th long weld is welded, so that the middle plate is formed integrally, then the 6th ring long weld of the edge plate is symmetrically welded, and finally the side plate and the bottom plate are to be welded. After the fillet weld is completed, the No. 7 ring long weld is welded.
After the 214 floor inspection plate is welded, the weld is inspected one by one by vacuum method.
Apply soapy water to the weld at the time of inspection, then fasten the vacuum box to the weld to be inspected, seal the rubber around the box, and then start a 2夂4 air pump. When vacuum, reach the vacuum required by the design. 4 000 yang, close the valve of the suction pipe, see through the transparent glass on the vacuum box to see if the weld is coated with soapy water, and it is not qualified. Only 4 places are found in the actual test. All post-weld inspections are qualified to meet the airtightness requirements of the gas cabinet.
The assembly and welding of the piston plate of the 22-piston plate is basically the same as that of the bottom plate, and is carried out directly on the bottom plate. The lap joint of the middle plate and the edge plate of the piston plate must be welded after the concrete dam of the piston is poured. And the piston plate gas lifts the piston and then uses the piston support to prop up the piston. At this time, the welder can enter the welding. The inspection of the piston plate weld seam utilizes the pressure of the gas in the gas cabinet during the commissioning phase of the gas cabinet, and the operator stands on the piston plate. Apply soapy water directly to the test.
23 gas cabinet columns are constructed with 24 gas cylinders 00, 200, 8, and 12, distributed uniformly along the wall. Each column is connected by bolts and then welded to the joint. The center line is marked on the inner surface of each column, and the scale is marked as a unit to control the balance and lifting speed of the top of the cabinet during the lifting process.
231 The first section of the column is installed to ensure that the column top of the first column is at the same level, and the elevation of the bottom of the column is controlled. The 381 thick column bottom plate is not welded to the column first, and the bottom plate is separately installed. The installation is made by sitting slurry and horn. The level of the column bottom plate is adjusted by the water level meter. After the concrete strength under the bottom plate reaches the requirement, the bottom plate is fixed by the column bolts, and the position of the column is measured and marked on the bottom plate of the column. Then, the first column was lifted into the bottom of the column with the Shen 3 type tower crane. The verticality control was carried out with two theodolites, and the distance between the columns was controlled by a steel ruler. Section 1 Column adjacent column top elevation allowed deviation 51 between columns allowed deviation 10 distance between columns Welding.
2 welding sequence arranges four welders to weld symmetrically, firstly offsetting the amount of weld shrinkage when the column is connected to the side plates.
23.2 Installation of the middle column The installation of the center column is carried out by the tower crane with the tower crane. The top of the cabinet serves as the operation platform for the column connection, and the top of the cabinet is lifted with the hoist. The allowable deviation of the middle column is the same as that of the first column.
23.3 The installation and installation method of the uppermost column is the same as the lower column. The adjacent column top mark is still allowed to deviate. The column top column elevation is allowed to be offset. The top distance between the columns is 151. The allowable deviation is 5 perpendicular and the circumference of the next column. Ugly 1 radial direction 3, ± 71 verticality and the first section of the column circumferential direction 25 radial direction 5, +25, when installing the last section of the column, the upper end is welded 1.51 long side 00, 200 at the top plus welded connecting plate, so that The circular walkway and the top arch beam are in place.
The outer ring plate of the top beam of the cabinet is used for the installation and installation of the upper and lower arch beams, and the top of the roof is installed for lifting.
24.1 Cabinet top beam outer ring plate production installation cabinet top beam outer ring plate thickness is called bending radius ruler = 23036 height 500 is rolled up by the rolling machine, the arc test is carried out with the sample plate, and the assembly position is determined on the bottom plate to determine the assembling position of the outer ring outer ring plate. Temporary spot welding limit position, segmented butt joint assembly, so that the horizontal tolerance of the outer ring plate of the top beam of the cabinet is ±5 perpendicularity. The allowable deviation is the distance from the main column of the 4th column to the outer ring plate. The production of the upper and lower arch beams of 24.2 The top arch beam of the installed gas cabinet is made of 160, 100, and 12 bends, and the bending radius of 531,401 points is arranged in a crisscross shape. During installation, the temporary mounting of the top arch beam is made on the piston plate according to the crown of the beam. A total of five frames are made, one in the middle, and two in the vertical and horizontal directions. Place the top arch beam to be installed on the piston plate to overlook the projection line. During installation, the tower crane is first hoisted into the longitudinal two arched arch beams on the mounting bracket, and the spatial position of the overhead roof beam is corrected according to the pay-off line on the piston plate. After adjustment, the two dome arch beams are placed in the respective sections. The joint is affixed to the welded plate, and the two ends of the top beam are welded to the outer ring plate of the top beam of the cabinet. According to this method, the upper two arched beams are installed. Finally, the other arch beams can be welcomed by the four dome arch beams, and the two ends of the beams are welded to the periphery to be paved. In order to make the inside of the gas cabinet transparent and to hoist the internal bracket in the future, the outermost ring top plate is not laid, and the other parts of the top plate of the top of the cabinet are installed and assembled after the welding is completed. Then, 24 lifting lugs are welded on the ring beam plate, transferred and rotated by 24 columns, and the column baffle is welded on the outer ring plate of the top beam to be restrained.
According to the design paper, the gas cabinet elevation is +34.950. The platform and the outer platform are connected with the top of the cabinet to form an inner and outer whole. It can rise along the main column, and the cabinet top lifting and the gas cabinet side panel lifting can be carried out on this platform. The lifting method of the top of the cabinet is to fasten the hoop on the column, 24 10 hoists are hung on the hoop, and the lower hook of the hoist is hung on the outer ring lug of the top arch of the cabinet, and then lifted to stop with 24 hoists. Adjust the time. Hang the pendant at the center of the top arch beam to calibrate the center of the center of the cabinet. When lifting to the first wall panel, stop lifting, install the second belt panel, and install the upper column on the top of the cabinet. The top of the cabinet is raised in turn, and finally the top of the cabinet is raised to the design position by the 1.5-long column and placed in position.
25 gas cabinet side panel construction 251 side panel production side panel height is divided into 25 belts, of which 1225 strip thickness 6 intermediate strip thickness 4.5 each strip design length 6098 construction using a fixed-length open flat, reduced a large number Splicing workload. The bending radius of the side plate is 23292, so the elastic deformation of the steel plate can be directly used, and the siding tire frame can be made on the ground according to the design requirements. The arc length of the tire frame is slightly longer than the plate, which is 65 (1), and each side plate only needs to be laid on The above can be used, and the 2125, 80, and 8 side plates which are pre-bent are welded to strengthen the angle steel, so that the bending curvature of each side plate can be hoisted.
252 side plate installation The first side wall plate installation should be reserved. The side plates are not installed, so that the personnel and articles and the internal components of the cabinet can be accessed. The side plates of the first belt side plate and the bottom plate are all installed. Re-welding.
The design of the side panels is changed from the design to the lap joint. The lap length is 30. The reason is that the side panels are all open, the upper and lower ports are not easy to be right, the thickness is thin, the deformation will be greater during welding, the construction progress and Quality is difficult to guarantee. The use of lap joints has well overcome the above questions.
3When welding each side plate, firstly weld the butt joint between the side plates, and then lap the ring joint between the back welding bands.
4 Take the installation spot welding on the side plate and then weld the lower side of the arch, and install 41 1596, and remove the charm. Welding requirements are higher.
A large number of work such as 5-stage board installation welding anti-corrosion is a high-altitude operation, and the side outer wall welding is carried out by using an elevation of +34.950. When the inner wall of the side panel is installed, the structural characteristics of the gas cabinet are used to make an auxiliary platform, and the horizontal support in the gas cabinet is supported by the horizontal support. The platform of the cabin is in seven parts, and after the installation of the upper rail of the eight columns, the average distribution is 24 A 10 chain hoist, the upper part is hung on the manhole of the top cover, and the hand is adjusted upwards and downwards by hand. The welder can weld the inner wall weld of the side plate on the walkway.
The lap length of the inspection side panel of the 253 side panel should be greater than 301 with a steel ruler. The side plate under 15 967 has airtightness requirements. The part of the butt joint is checked by kerosene method. The hoop weld is changed to overlap. It is not suitable for testing the weld with kerosene method. The direct application of soapy water to the leak detection of the internal structure of the internal structure of the gas cabinet is not described here.
The piston fence of the 261 piston fence can be assembled on the ground platform first, and then transported into the cabinet from the temporary gate of the side panel. Then, the trusses are first symmetrically erected according to the cross direction perpendicular to each other through the tower crane and the internal hoist. The top hook is not installed at this time. Subsequently, the remaining trusses and the connecting members of the trusses 21 are hoisted, and the elevation of the radial and tangential axes of the truss is used to adjust the elevation. After the retest is correct, tighten the mounting bolts and finally weld the joints. The verticality of the piston fence column is allowed to deviate. The radial 015 is tangential to 10 columns. The horizontal tolerance is ±1. The distance between the inner side of the gantry and the outer circumference of the piston fence beam is ±25. The installation procedure is the same as that of the piston fence.
The gantry frame installation sequence bracket horizontal skeleton horizontal branch, the oblique press box member installation sequence sealing connecting plate 1 column bracket horizontal support diagonal pull support aisle platform 4 sealing connecting piece ladder f railing upper and lower retaining wheel.
The verticality of the gantry at the bottom of the arranging column is allowed to be biased. 6 The top level of the pedestal is allowed to be biased ± The radial tolerance of the bottom plane of the fence is allowed. The tolerance of the horizontalness of the 201 is ± the tolerance of the verticality after assembly ± 20 of the outer circumference of the top beam and the inner wall of the side panel. The external inclined ladder and the bad aisle are installed at the same time as installing the siding, and the inclined ladder and the ring walkway are installed, which is for the future. The construction is convenient, and the conclusion is that the Nangang Gas Mine is the second construction project of our company. Pre-construction. Recognize the pre-construction plan and select a reasonable construction square and set up the construction. When the bottom plate is welded, the intermittent welding and the back-welding method are adopted. The position and elevation of the column are the key points of control. The construction sequence of the top of the gas cabinet is the production of the top and bottom arch beams of the top beam of the cabinet, and the installation of the top and bottom arch beams.
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