Method and device for replacing bottom plate of steel tank

Abstract

The invention discloses a method and device for replacing a bottom plate of a steel tank, and the method comprises the following steps: lifting the steel tank to a preset height, cutting a welding seam at the joint of the bottom plate of the steel tank and the bottom of a tank body so as to completely separate the bottom plate from the tank body, and after separation, cutting and dragging the bottom plate in blocks; the multiple to-be-spliced bottom plate modules are conveyed into the tank body, the to-be-spliced bottom plate modules which are adjacent in pairs are subjected to splicing and weld joint anti-corrosion treatment, and a new bottom plate is formed by splicing the multiple bottom plate modules; and after the new bottom plate is formed, the tank body is lowered, after the perpendicularity of the tank body meets the requirement, the new bottom plate and the bottom of the tank body are welded, and the repaired steel tank is formed. According to the method, deformation of the tank body in the process of replacing the bottom plate of the steel tank is avoided, the phenomenon that after the bottom plate is replaced, welding seams of the bottom plate are corroded under erosion of harmful substances is prevented, the service life of the steel tank is greatly prolonged, the use safety of the steel tank is improved, and the repair cost of the steel tank is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of steel tank maintenance, in particular to a method and device used when replacing a bottom plate of a large steel tank. Background Art

[0002] At present, many oil depots or water plants use steel tanks to store items. Due to lax quality control during construction, improper use and maintenance, external environment, and years of use, defects may appear in the steel tanks, especially the bottom plates. If they are completely abandoned, it will lead to a waste of resources. Therefore, partial repair and reuse has become a new idea.

[0003] During a partial repair, the bottom plate of the original steel tank is removed, and the new bottom plate is welded to the bottom of the original steel tank body. However, due to the large size of the steel tank, most of the bottom plate cannot be formed at one time when replacing the new bottom plate. A new bottom plate needs to be formed by assembly and welding, and then welded to the bottom of the original tank body to form a new steel tank. This leads to the following problems: the welds between the two bottom plates are very susceptible to corrosion due to the erosion of harmful substances in the lower foundation. In addition, before and after the bottom plate is replaced, that is, whether the original bottom plate is removed from the bottom of the original steel tank body or the new bottom plate is welded to the bottom opening of the original tank body, there is uneven force at the lower opening of the tank body, which makes the tank body very prone to local deformation. All these problems will affect the subsequent use of the repaired tank body and the steel tank. Summary of the Invention

[0004] The purpose of the present invention is to overcome the problems existing in the above-mentioned prior art and provide a method and device for replacing the bottom plate of a steel tank, so as to avoid deformation of the tank body during replacement of the bottom plate of the steel tank, prevent corrosion of the bottom plate welds due to erosion by harmful substances after replacement of the bottom plate, greatly extend the service life of the steel tank, improve the safety of the use of the steel tank, and reduce the maintenance cost of repairing the steel tank.

[0005] In order to achieve the above object, the present invention provides a method for replacing a steel tank bottom plate, comprising:

[0006] Lift the steel tank to a preset height and cut the weld where the bottom plate of the steel tank is connected to the bottom of the tank body so that the bottom plate and the tank body are completely separated;

[0007] After the bottom plate is completely separated from the tank body, the bottom plate is cut off and dragged away in pieces;

[0008] Transporting multiple bottom plate modules to be spliced ​​for forming a new bottom plate of a steel tank into the tank body, and performing splicing and weld anti-corrosion treatment on two adjacent bottom plate modules to be spliced, so as to form a new bottom plate by splicing multiple bottom plate modules;

[0009] After the new bottom plate is formed, the tank body is lowered. After the verticality of the tank body meets the requirements, the new bottom plate is welded to the bottom of the tank body to form a repaired steel tank.

[0010] Preferably, the step of lifting the steel tank to a preset height and cutting the weld at the connection between the bottom plate of the steel tank and the bottom of the tank body so as to completely separate the bottom plate from the tank body comprises:

[0011] Lift the steel tank to a preset height and perform a cutting operation along the weld seam where the bottom plate and the bottom of the tank body are connected inside the steel tank to separate the bottom plate from the tank body;

[0012] After the bottom plate inside the steel tank is separated from the tank body, the tank body is lifted to a preset height, and a cutting operation is performed on the outside of the steel tank along the weld where the bottom plate and the bottom of the tank body are connected so that the bottom plate and the tank body are completely separated.

[0013] Preferably, the steps of splicing and anti-corrosion treatment of welds of two adjacent base plate modules include:

[0014] A blocking strip is placed on one side of the gap between the first floor module and the second floor module adjacent to each other;

[0015] Using welding equipment to weld the other side of the gap between the first floor module and the second floor module;

[0016] During the welding process, when the welding temperature reaches a temperature at which the blocking strip is melted, the blocking strip is melted by the heat and adheres to the gap between the two bottom plate modules to seal the gap.

[0017] Preferably, the first base plate module and the second base plate module are two base plate modules to be overlap-welded.

[0018] Preferably, the blocking strip is placed at the lower end of the first floor module and the second floor module to be overlap-welded.

[0019] Preferably, the blocking strip is placed before the lower end of the first and second floor modules to be overlap-welded, further comprising the step of welding a thin-walled steel plate to the lower end of the floor.

[0020] Preferably, the first base plate module and the second base plate module are two base plate modules to be butt-welded.

[0021] Preferably, the blocking strip is arranged on one side of a gap between the first floor module and the second floor module to be butt-welded.

[0022] Preferably, after the tank body is lowered, the verticality of the tank body needs to be monitored by a tilt monitoring structure so that the verticality of the tank body meets the requirements.

[0023] Preferably, during the complete separation of the bottom plate from the tank body, deformation of the tank body needs to be prevented.

[0024] Preferably, preventing the tank body from deforming includes the step of supporting the inner wall of the tank body by an anti-deformation support structure.

[0025] In addition, the present invention also provides a device for replacing the bottom plate of a steel tank, comprising: a weld corrosion protection structure for preventing corrosion at the weld seam of the bottom plate when the bottom plate of the steel tank is replaced.

[0026] Preferably, the weld anti-corrosion structure includes: a sealing strip that is placed on one side of the gap between the first steel tank bottom plate and the second steel tank bottom plate to be welded and melts when the welding equipment welds the other side of the gap and adheres to the gap between the two bottom plates to seal the gap.

[0027] Preferably, the sealing strip is an asphalt strip.

[0028] Preferably, the sealing strip is an asphalt strip containing an expansion agent.

[0029] Preferably, the first steel tank bottom plate and the second steel tank bottom plate are two steel tank bottom plates to be overlap-welded.

[0030] Preferably, the blocking strip is placed at the lower end of the first steel tank bottom plate and the second steel tank bottom plate to be overlap-welded.

[0031] Preferably, it also includes a thin-walled steel plate welded to the lower end of the first steel tank bottom plate and the second steel tank bottom plate to be overlapped, and the sealing strip is arranged outside the thin-walled steel plate.

[0032] Alternatively, the first steel tank bottom plate and the second steel tank bottom plate are two steel tank bottom plates to be butt-welded.

[0033] Preferably, the blocking strip is placed on one side of the gap between the first steel tank bottom plate and the second steel tank bottom plate to be butt-welded.

[0034] Furthermore, it also includes an anti-deformation support structure for preventing the side wall of the tank body from deforming when the steel tank bottom plate is replaced.

[0035] Preferably, the anti-deformation support structure includes: a support frame fixed to the center of the bottom plate of the steel tank; a jack fixedly connected to the support frame; a support ring fixedly connected to the piston rod of the jack; and a plurality of telescopic support rods arranged around the outer periphery of the support ring for supporting the inner wall of the steel tank body.

[0036] Preferably, the plurality of telescopic support rods extend radially outward along the support ring.

[0037] Preferably, the support ring has a track, and one end of the telescopic support rod is slidably connected to the support ring track.

[0038] Preferably, it further comprises a locking assembly for locking one end of the telescopic support rod at the support ring track.

[0039] Preferably, the telescopic support rod includes: a first support rod with one end slidingly connected to the support ring track; a second support rod with one end for contacting the inner wall of the steel tank body; and sleeves at both ends for connecting the first support rod and the second support rod respectively.

[0040] Preferably, the other end of the first support rod and the other end of the second support rod are respectively provided with external threads, and the inner wall of the sleeve is provided with internal threads adapted to the external threads of the two support rods.

[0041] Preferably, it also includes a diagonal structure for strengthening the supporting strength of the multiple telescopic support rods.

[0042] Preferably, the oblique-stayed structure comprises: a vertical support rod fixedly connected to the support ring and extending in the vertical direction; and an inclined pull rod having one end connected to the vertical support rod and the other end connected to the telescopic support rod.

[0043] Furthermore, it also includes a tilt monitoring structure for monitoring the verticality of the tank body.

[0044] Preferably, the tilt monitoring structure includes multiple tilt monitoring components, and the tilt monitoring components include: a bracket installed on the outer side wall of the tank body; a protective cover installed on the bracket; multiple adjustment rods installed on the bottom of the protective cover; a base plate installed on the multiple adjustment rods; and an inclinometer installed on the base plate.

[0045] Furthermore, it also includes a tank body lifting structure for lifting the steel tank body.

[0046] Preferably, the tank lifting structure includes: a plurality of electric hoists arranged on the outer periphery of the steel tank; and a plurality of lifting ears arranged on the outer wall of the steel tank for corresponding connection with the hooks of the electric hoists.

[0047] Compared with the prior art, the method for replacing the bottom plate of a steel tank of the present invention has the advantages of preventing the tank body from being deformed during the process of replacing the bottom plate of the steel tank, and after the bottom plate is replaced, the welds of the bottom plate can be effectively sealed, thereby effectively preventing the welds of the bottom plate from being corroded by harmful substances, greatly extending the service life of the steel tank, improving the safety of the use of the steel tank, and reducing the maintenance cost of the steel tank repair.

[0048] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a schematic structural diagram of the first base plate module and the second base plate module during lap welding of the present invention;

[0050] Figure 2 This is a structural diagram of the first base plate module and the second base plate module when they are butt-welded;

[0051] Figure 3a This is a schematic diagram of the structure of a steel tank body supported by the anti-deformation support structure of the present invention;

[0052] Figure 3b It is a structural schematic diagram of a steel tank body supported by the anti-deformation support structure of the present invention during the process of lifting the tank body;

[0053] Figure 4 It is a partial structural schematic diagram of the anti-deformation support structure of the present invention;

[0054] Figure 5 This is a half-section view of the telescopic support rod and the support ring of the present invention when connected;

[0055] Figure 6 Schematic diagram of the telescopic support rod of the present invention locked in the support ring track by the locking bolt (only the portion of the telescopic support rod located in the track is shown);

[0056] Figure 7 It is a schematic diagram of the position of the tilt monitoring structure installed on the tank body of the present invention;

[0057] Figure 8 is a schematic structural diagram of the tilt monitoring assembly of the present invention;

[0058] Figure 9 The present invention is a flow chart of a method for replacing a bottom plate of a steel tank. DETAILED DESCRIPTION

[0059] The present invention provides a device for replacing the bottom plate of a steel tank, which includes: a weld corrosion protection structure for preventing corrosion at the weld seam of the bottom plate when the bottom plate of the steel tank is replaced. Figure 1 、 Figure 2 The figures show two schematic diagrams of the weld corrosion protection structure of the present invention. As can be seen from the figures, the weld corrosion protection structure of the present invention includes: a first baseplate module 1 and a second baseplate module 5 to be welded; a sealing strip 3 positioned on one side of the gap formed between the first and second baseplate modules to be welded, and which melts when the welding equipment welds the other side of the gap, thereby bonding to the gap between the two baseplates to seal the gap. Furthermore, welding equipment (not shown) is required to weld one side of the gap between the first and second baseplate modules to be welded, and this equipment uses existing technology.

[0060] The first base plate module 1 and the second base plate module 5 to be welded in the present invention can be two base plates to be overlapped and welded (such as Figure 1 As shown), it can also be two base plates to be butt-welded (as shown Figure 2 Regardless of the welding method used, the present invention places a blocking strip on one side of the gap formed between the first and second baseplate modules to be welded. This blocking strip is an asphalt strip containing an expansion agent, which is made by solidifying the asphalt with an expansion agent in the prior art. Thus, when the welding equipment welds the other side of the gap between the two baseplates, the blocking strip will melt and expand when the welding temperature reaches a melting point, and then adhere to the gap between the two baseplates, thereby achieving the purpose of sealing the gap between the two baseplates. This effectively prevents the baseplate weld from corroding due to the erosion of harmful substances, greatly extending the service life of the steel tank and improving the safety of the steel tank. The low production cost of the blocking strip also greatly reduces the maintenance cost of repairing the steel tank.

[0061] For the first floor module and the second floor module to be overlapped and welded, the bottom plate end portion ( Figure 1 A thin-walled steel plate 4 with a triangular cross-section is welded to the upper and lower plates (the middle is the end of the second bottom plate module), and an asphalt strip (with an expansion agent added) is placed on the outside of the thin-walled steel plate. When the two steel tank bottom plates (hereinafter referred to as steel plates) are overlap-welded, the asphalt strip melts when the welding temperature reaches its melting point and expands under the action of the expansion agent, bonding to the overlap gap between the upper and lower steel plates, sealing the gap at the overlap and preventing the weld from being corroded by harmful substances on the base.

[0062] It should be noted that when two steel plates are overlapped and welded, the ends of the steel plates to be overlapped are beveled to form inclined surfaces (such as Figure 1 As shown), in this way, the accumulation area of ​​solder between the two steel plates can be increased through the inclined surface of the upper steel plate, thereby increasing the welding strength, and the contact area between the thin-walled steel plate and the asphalt strip and the two steel plates can be reduced through the inclined surface of the lower steel plate, and the gap between the overlapped parts of the two steel plates can be completely closed to prevent corrosion by harmful substances.

[0063] As for the butt-welded first base plate module and second base plate module, the present invention sets an asphalt strip with an expansion agent at the bottom of the two steel plates. The asphalt strip melts under the high temperature conditions of welding and expands under the action of the expansion agent. The gravity of the two steel plates can squeeze the asphalt strip, thereby sealing the gap and preventing the weld from being corroded by harmful substances in the foundation.

[0064] The present invention has a weld corrosion-resistant structure. During operation, it is only necessary to place the sealing strip at or near the gap between the two steel tank bottom plates to be welded, and then use welding equipment such as a welding gun to weld the gap. The operation is simple and convenient, which improves maintenance efficiency and reduces maintenance costs. In addition, the gap between the two steel plates can be completely sealed, effectively preventing corrosion by harmful substances.

[0065] In addition, the device of the present invention also includes an anti-deformation support structure for preventing the side wall of the tank from deforming when the steel tank bottom plate is replaced, such as Figure 3a-Figure 4 The following are schematic diagrams of the anti-deformation support structure and the steel tank supported by the present invention. Figure 3a It can be seen that the anti-deformation support structure of the present invention includes: a support frame 16 fixed to the center of the bottom plate 200 of the steel tank; a jack 17 whose cylinder is fixedly connected to the support frame; a support ring 15 fixedly connected to the piston rod of the jack; and a plurality of telescopic support rods arranged on the outer periphery of the support ring for supporting the inner wall of the steel tank body 100.

[0066] The bottom of the support frame of the present invention is fixedly connected (such as welding) with the steel tank bottom plate (the bottom plate can be the original bottom plate when the bottom of the original tank body is removed or a bottom plate located in the center of the original bottom plate. For example, a steel plate is first cut in the center of the original bottom plate, and the area of ​​the steel plate is suitable for the installation of the support frame. The bottom plate at the corresponding position of this steel plate can be installed last after the construction of the bottom plates of other parts is completed). A cylinder body of a jack is fixed on the top of the support frame, and a circular support ring is fixedly installed at the end of the piston rod of the jack. A plurality of telescopic support rods extending radially outward are provided on the outer periphery of the support ring. The telescopic support rods can adjust their positions relative to the support ring according to actual support needs and be locked at the position by a locking assembly after reaching the desired position. The ends of the plurality of telescopic support rods can contact the inner wall of the steel tank body (see Figure 3a ), so that when the original steel tank bottom plate is removed from the bottom of the original tank body or a new bottom plate is welded to the lower opening of the tank body from which the original bottom plate has been removed, the tank body can be supported by the telescopic support rod, so that the area where the local deformation of the bottom of the tank body occurs can be adjusted to restore the tank body to its original shape.

[0067] Wherein, the support ring is a support ring with a track, such as Figure 5 、 Figure 6As shown, one end of the telescopic support rod is positioned within the support ring track and can slide along the track. The outer wall of the support ring is designed with a stepped groove, smaller on the outside and larger on the inside, forming the track. One end of the telescopic support rod is T-shaped, with a clip that fits within the larger diameter portion of the support ring track's stepped groove and a protruding portion located at the center of the clip that passes through the smaller diameter portion of the stepped groove. The clip is positioned within the track and can move along the track, allowing the telescopic support rod to adjust its position within the track according to the actual needs of the repair operation. When the telescopic support rod reaches the desired position relative to the support ring, a locking assembly can be used to lock the telescopic support rod in that position.

[0068] The locking assembly includes two or more locking bolts 19 that can pass through the telescopic support rod clamping portion. By passing the locking bolts through the telescopic support rod clamping portion and resting against the inner side wall of the support ring track, the radial position of the telescopic support rod and the support ring can be locked to prevent the telescopic support rod from moving radially along the support ring. Accordingly, a plurality of through holes are provided on the telescopic support rod clamping portion. Furthermore, the locking assembly can also include a pad 20 that can be fitted onto the outside of the telescopic support rod clamping portion. The pad can be a plastic pad. The inner ring size of the pad is equivalent to the outer size of the telescopic support rod clamping portion, and the outer ring size is equivalent to the inner wall size of the track. The pad can be used to lock the relative position of the telescopic support rod and the support ring in the height direction to prevent the telescopic support rod from shaking relative to the support ring.

[0069] And as Figure 3a-Figure 4 As shown, the telescopic support rod of the present invention comprises: a first support rod 12, one end of which is slidably connected to a support ring track; a second support rod 10, one end of which contacts the inner wall of the steel tank; and sleeves 11 at both ends, each for connecting the first and second support rods. The other ends of the first and second support rods are each provided with external threads, and the inner walls of the sleeves are provided with internal threads that mate with the external threads of the two support rods. When the tank deforms, the length of the telescopic support rod can be adjusted by rotating the sleeves to support the deformed inner wall of the tank, thereby adjusting the deformed area of ​​the tank.

[0070] Since the inner diameter of the tank body of the present invention is very large, usually more than 10 meters, the length of the support rod is also very long. Since the support rod is a slender rod, it will bend when subjected to force during the process of single support. Therefore, the present invention also provides an inclined pull assembly for strengthening the support strength of multiple telescopic support rods. As shown in Figure 3, the inclined pull assembly includes a support fixedly mounted on the upper part of the support ring, a vertical support rod 14 connected to the support, and multiple inclined pull rods 13, one end of which is connected to the top of the vertical support rod and the other end is fixedly connected to the first support rod of the multiple telescopic support rods. In order to prevent the supporting force of the inclined pull assembly on the support rod from being affected when the telescopic support rod adjusts its position (i.e., angle) relative to the track, the support of the present invention and the vertical support rod can be connected together by a rotational connection, and after the vertical support rod is rotated to the desired angle, the position of the vertical support rod relative to the support can be locked. The structure of this part can be referred to the existing technology and will not be described in detail here.

[0071] Furthermore, an arcuate support plate 9 may be installed at a portion of the inner wall of the tank body that contacts the telescopic support rod. The shape of the arcuate support plate matches the inner wall of the tank body and is fixedly connected thereto, such as by welding.

[0072] It should be noted that the number and size of the telescopic support rods can be determined according to the size of the tank body.

[0073] The present invention has an anti-deformation support structure, which can drive the support ring and the telescopic support rod to rise and fall synchronously with the tank body through the jack, thereby ensuring the safety of the tank body during the lifting process, and supporting the inner wall of the steel tank body through multiple telescopic support rods arranged on the outer periphery of the support ring, thereby preventing local deformation of the tank body and realizing adjustment of the local deformation area of ​​the tank body, which is beneficial to the repair of the tank body and continued use after repair, and can be suitable for partial replacement of the tank wall of similar large-sized tank bodies.

[0074] In addition, the present invention also includes a tilt monitoring structure for monitoring the verticality of the tank body during the replacement of the steel tank bottom plate. Figure 7 As shown, the tilt monitoring structure includes a plurality of tilt monitoring components 21, which can be installed at any position of the outer wall of the tank as needed (such as Figure 7 As shown), it can also be installed only at the appropriate position on the top of the tank. In addition, it also includes an alarm component for sending an alarm signal when the verticality of the tank does not meet the requirements, which can adopt the sound and / or light alarm component of the prior art.

[0075] Among them, Figure 8As shown, the tilt monitoring assembly can adopt the following structure, including: a bracket 26 mounted on the outer wall of the tank; a protective cover 22 mounted on the bracket; multiple adjustment rods 25 mounted on the bottom of the protective cover; a base plate 24 mounted on the multiple adjustment rods; and an inclinometer 23 mounted on the base plate. The base plate is supported by the adjustment rods, and the height of the inclinometer can be adjusted as needed. The inclinometer can be an NCX-1APS point inclinometer. The inclinometer is mounted on the outer wall of the tank being measured. The tilt deformation generated by the outer wall of the tank is transmitted to the inclinometer's inclinometer sensor via the mounting bracket. The inclinometer's inclinometer sensitive element senses the tilt change and outputs a voltage signal corresponding to the tilt change. The measured voltage value can be converted into the inclination angle change of the inclinometer and the tank.

[0076] The inclinometer's inclinometer-sensitive element uses a servo accelerometer to measure the component of the gravity vector g in a plane perpendicular to the sensor's axis. When the accelerometer's sensitive axis forms an angle with the horizontal, the output voltage changes. The amount of tilt and deformation of the tank being measured corresponds to the voltage output by the inclinometer. The positive or negative sign of this voltage measurement indicates the direction of the tilt angle change relative to the zero point. During design, preset values ​​can be set to indicate whether the tank's verticality meets requirements, such as a maximum displacement deviation. When this maximum value is exceeded, an alarm component sounds an alarm signal. Upon receiving the signal, on-site technicians check the deviation data and make adjustments to the tank based on the monitored data deviation.

[0077] The present invention adopts a tilt monitoring structure to monitor the verticality of the tank body, which can prevent the tank body from tilting due to external factors during the maintenance of the steel tank.

[0078] In addition, the present invention also includes a tank lifting structure for lifting a steel tank body, such as Figure 3a 、 Figure 3b As shown, it includes: multiple electric hoists 7 installed on the outer perimeter of the steel tank; multiple lifting lugs 8 provided on the outer wall of the steel tank for corresponding connection with the hooks of the electric hoists. During the design, multiple support columns 6 with their bottoms fixed to the ground are installed on the outer perimeter of the steel tank, and the electric hoists are mounted on the support columns.

[0079] Specifically, electric hoists are placed along a circle of support columns around the outside of the steel tank. The number and spacing of the support columns and electric hoists are determined by the weight of the tank and the thickness of the tank wall. For example, if the tank weighs approximately 120 tons, 18 10-ton electric hoists can be evenly spaced, and lifting lugs welded approximately 50 cm from the bottom of the tank. The electric hoist hooks are connected to the lifting lugs to lift the tank. Once all the electric hoists are connected, they are connected to the central control cabinet. Through weak current signal transmission, the electric hoists can be activated simultaneously or individually. Under the control of the central control cabinet, the force applied to each electric hoist is consistent.

[0080] It should be noted that all power components of the present invention are connected to the central control cabinet 18 through weak wires to perform corresponding operations under the control of the control cabinet.

[0081] In addition to providing the above-mentioned device for replacing the bottom plate of a steel tank, the present invention also provides a method for replacing the bottom plate of a steel tank using the above-mentioned device, such as Figure 9 FIG. 1 is a flow chart of a method for replacing a bottom plate of a steel tank according to the present invention. As can be seen from the figure, the method of the present invention includes:

[0082] Lift the steel tank to a preset height and cut the weld where the bottom plate of the steel tank is connected to the bottom of the tank body so that the bottom plate and the tank body are completely separated;

[0083] After the bottom plate is completely separated from the tank body, the bottom plate is cut off and dragged away in pieces;

[0084] Transporting multiple bottom plate modules to be spliced ​​for forming a new bottom plate of a steel tank into the tank body, and performing splicing and weld anti-corrosion treatment on two adjacent bottom plate modules to be spliced, so as to form a new bottom plate by splicing multiple bottom plate modules;

[0085] After the new bottom plate is formed, the tank body is lowered. After the verticality of the tank body meets the requirements, the new bottom plate is welded to the bottom of the tank body to form a repaired steel tank.

[0086] Below, the method of the present invention is described in detail.

[0087] S01. Lift the steel tank to a preset height and cut the weld at the connection between the bottom plate and the bottom of the tank body to completely separate the bottom plate from the tank body;

[0088] Lift the steel tank to a preset height and cut the weld where the bottom plate of the steel tank is connected to the bottom of the tank body so that the bottom plate and the tank body are completely separated. This includes:

[0089] Lift the steel tank to a preset height and perform a cutting operation along the weld seam where the bottom plate and the bottom of the tank body are connected inside the steel tank to separate the bottom plate from the tank body;

[0090] After the bottom plate inside the steel tank is separated from the tank body, the tank body is lifted to a preset height, and a cutting operation is performed on the outside of the steel tank along the weld where the bottom plate and the bottom of the tank body are connected so that the bottom plate and the tank body are completely separated.

[0091] Specifically, a circle of support columns is arranged along the outer perimeter of the steel tank, and electric hoists are placed on the support columns. The number and spacing of the support columns and electric hoists are determined according to the weight of the steel tank and the thickness of the tank wall. For example, if the steel tank weighs approximately 120 tons, 18 10-ton electric hoists can be evenly arranged, and lifting lugs can be welded approximately 50 cm from the bottom of the tank. The electric hoist hooks are connected to the lifting lugs to lift the steel tank. Once all the electric hoists are connected, they are connected to the central control cabinet. Through weak current signal transmission, the electric hoists can be activated simultaneously or individually according to actual needs. Under the control of the central control cabinet, the force applied to each electric hoist is consistent.

[0092] Initially, the electric hoist is placed in a semi-stressed state, and the weld between the bottom (i.e., bottom plate) and the tank wall (inner wall of the tank) of the steel tank is cut (the tank body is installed on the bottom plate, and the outer edge of the bottom plate extends about 5 cm outside the tank wall) to separate the tank bottom from the tank wall. After the cutting is completed, the tank body is lifted by the electric hoist to a height of about 30 cm. Cut the weld between the bottom plate and the tank wall on the outside of the tank body to completely separate the bottom plate from the tank wall (such as Figure 3b shown).

[0093] During the complete separation of the tank bottom and the tank wall (i.e., the bottom plate and the tank body), it is also necessary to prevent the tank body from being deformed.

[0094] To achieve this, the present invention reinforces a circle of 12# curved I-beams at the same height as the lifting lugs where the force is greatest, and welds them to the inner wall of the tank. At the connection points between the I-beams and the tank wall, 200×200×10 stainless steel pads are welded and fixed at intervals of 1200mm. This creates an integrated force distribution around the lower circumference of the tank, preventing uneven force at the lower opening and deformation of the tank. Furthermore, an anti-deformation support structure can be installed within the tank to adjust localized deformation of the tank.

[0095] Among them, the following methods are used to support the tank body through the anti-deformation support structure:

[0096] When cutting the original bottom plate, cut a steel plate in the center of the original bottom plate. The steel plate should be large enough to accommodate the installation requirements of the support frame of the anti-deformation support structure. This steel plate will be installed last after the construction of other parts is completed. The anti-deformation support structure is placed in the tank body, and the bottom of the support frame is fixedly connected to the cut steel plate in the center. The outer end of the telescopic support rod rests on the corresponding position of the inner wall of the tank.

[0097] As needed, the overall length of the telescopic support rod and its position on the support ring can be adjusted by rotating the sleeve. Once the telescopic support rod is positioned on the support ring, the locking bolt is screwed into the telescopic support rod's clamping portion, with the end resting against the side wall of the support ring track to lock the telescopic support rod in place. This prevents deformation of the tank's inner wall, thereby achieving control over deformation.

[0098] S02. After the bottom plate is completely separated from the tank body, the bottom plate is cut and removed in pieces;

[0099] After the bottom plate is completely separated from the tank body, the bottom plate inside the tank body is cut into pieces, and then a winch is used to drag the cut waste bottom plate material out of the tank body.

[0100] S03. Transporting multiple floor plate modules to be spliced ​​for forming a new floor plate of the steel tank into the tank body, and performing splicing and weld anti-corrosion treatment on two adjacent floor plate modules to be spliced, so as to form a new floor plate by splicing the multiple floor plate modules;

[0101] Since the bottom of the steel tank is corroded, the asphalt sand at the bottom of the tank often cannot meet the use requirements. Therefore, the original asphalt sand at the bottom of the tank needs to be replaced, and the new bottom plate is installed after the replacement is completed.

[0102] When installing the new bottom plate, a winch is first used to transport multiple bottom plate modules into the tank body, and then they are spliced ​​together and the welds are treated for corrosion protection to form a new bottom plate by splicing multiple bottom plate modules.

[0103] The splicing and weld anti-corrosion treatment of two adjacent base plate modules includes:

[0104] A blocking strip is placed on one side of the gap between the first floor module and the second floor module adjacent to each other;

[0105] Using welding equipment to weld the other side of the gap between the first floor module and the second floor module;

[0106] During the welding process, when the welding temperature reaches a temperature at which the blocking strip is melted, the blocking strip is melted by the heat and adheres to the gap between the two bottom plate modules to seal the gap.

[0107] Among them, when the first base plate module and the second base plate module of the present invention are two base plate modules to be overlapped and welded, a thin-walled steel plate is first welded at the end of the base plate located below, and then a sealing strip is placed at the end of the base plate module located below in the first base plate module and the second base plate module to be overlapped and welded, and then, welding equipment is used to weld the side of the gap at the overlap of the two base plate modules away from the thin-walled steel plate, so that when the welding temperature reaches the temperature that melts the sealing strip, the sealing strip is heated and melted and adheres to the gap between the two base plate modules, thereby sealing the gap.

[0108] When the first floor module and the second floor module are to be butt-welded, the blocking strip is placed on one side of the gap between the first floor module and the second floor module to be butt-welded, and then the other side of the gap at the butt joint of the two floor modules is welded using welding equipment.

[0109] S04. After the new bottom plate is formed, the tank body is lowered. After the verticality of the tank body meets the requirements, the new bottom plate is welded to the bottom of the tank body to form a repaired steel tank.

[0110] After the new bottom plate is formed, the tank body is lowered so that the new bottom plate can be welded to the bottom of the tank body to form the repaired steel tank.

[0111] Among them, after the tank body is lifted, it is easy to tilt because it will be affected by external factors during the maintenance process. If it is not handled and directly lowered, it will cause the tank body to tilt relative to the new bottom plate. This requires adjusting the verticality of the tank body first, and then welding the new bottom plate to the bottom of the tank body.

[0112] Before adjusting the verticality of the tank body, the verticality of the tank body needs to be monitored through the tilt monitoring structure, and then the verticality of the tank body is adjusted according to the monitoring results until it meets the preset requirements.

[0113] Among them, monitoring the verticality of the tank through the tilt monitoring structure includes the following steps:

[0114] According to actual needs, the brackets of multiple tilt monitoring components can be fixedly installed at any position on the outer wall of the tank body, or can be installed only at an appropriate position on the top of the tank body;

[0115] The tilt deformation of the outer wall of the tank is detected by the inclinometers of multiple tilt monitoring components, and the inclination angle of the tank is obtained;

[0116] According to the obtained tank inclination angle, determine whether the verticality of the tank meets the preset requirements;

[0117] If the verticality of the tank does not meet the preset requirements, the alarm component will emit an audible and / or visual alarm signal. After receiving the signal, the on-site technician will check the deviation data and then adjust the tank according to the deviation of the monitoring data until the verticality meets the preset requirements.

[0118] After the verticality of the tank body meets the requirements, the new bottom plate is welded to the inner and outer sides of the bottom of the tank body to form a new repaired steel tank.

[0119] Although the present invention has been described in detail above, the present invention is not limited thereto. Those skilled in the art can make modifications based on the principles of the present invention. Therefore, all modifications made in accordance with the principles of the present invention should be understood to fall within the scope of protection of the present invention.

Claims

1. A method for replacing a bottom plate of a steel tank, comprising: Lift the steel tank to a preset height and cut the weld at the connection between the bottom plate of the steel tank and the bottom of the tank body so that the bottom plate and the tank body are completely separated; After the bottom plate is completely separated from the tank body, the bottom plate is cut off and dragged away in blocks; A plurality of bottom plate modules to be spliced ​​for forming a new bottom plate of a steel tank are transported into the tank body, and two adjacent bottom plate modules to be spliced ​​are spliced ​​and weld anti-corrosion treatment is performed respectively, so that a new bottom plate is formed by splicing the plurality of bottom plate modules; After the new bottom plate is formed, the tank body is lowered. After the verticality of the tank body meets the requirements, the new bottom plate is welded to the bottom of the tank body to form a repaired steel tank.

2. The method according to claim 1, wherein the steel tank is lifted to a preset height, and the weld at the connection between the bottom plate of the steel tank and the bottom of the tank body is cut so that the bottom plate and the tank body are completely separated, comprises: Lift the steel tank to a preset height, and perform cutting along the weld where the bottom plate and the bottom of the tank body are connected inside the steel tank, so as to separate the bottom plate inside the steel tank from the tank body; After the bottom plate inside the steel tank is separated from the tank body, the tank body is lifted to a preset height, and a cutting operation is performed along the weld where the bottom plate and the bottom of the tank body are connected on the outside of the steel tank so that the bottom plate and the tank body are completely separated.

3. According to the method of claim 1 or 2, the steps of splicing two adjacent floor modules and performing weld anti-corrosion treatment include: A blocking strip is arranged on one side of the gap between the first floor module and the second floor module adjacent to each other; Using welding equipment to weld the other side of the gap between the first floor module and the second floor module; During the welding process, when the welding temperature reaches a temperature that melts the blocking strip, the blocking strip is melted by the heat and adheres to the gap between the two bottom plate modules to seal the gap. 4 . The method according to claim 3 , wherein the first floor module and the second floor module are two floor modules to be overlap-welded. 5 . The method according to claim 4 , wherein the blocking strip is disposed at a lower end of the first floor module and the second floor module to be overlap-welded.

6. The method according to claim 5, wherein the blocking strip is arranged before the lower end of the first floor module and the second floor module to be overlap-welded, and further comprises the step of welding a thin-walled steel plate to the lower end of the floor. 7 . The method according to claim 3 , wherein the first floor module and the second floor module are two floor modules to be butt-welded. 8 . The method according to claim 7 , wherein the blocking strip is arranged on one side of a gap between the first floor module and the second floor module to be butt-welded.

9. According to the method of claim 1, after the tank body is lowered, the verticality of the tank body needs to be monitored by a tilt monitoring structure so that the verticality of the tank body meets the requirements.

10. A device for replacing a bottom plate of a steel tank, comprising: A weld corrosion protection structure used to prevent corrosion at the bottom plate weld when the bottom plate of a steel tank is replaced.

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