1X330火力发电站烟囱钢内筒施工方案(英文).doc

3.5 construction statements for the steel liners erection3.5.1 preparation at the construction site: the embedded items will be installed along with the rising construction platform, complying severely with the requirements of the drawing (see the drawing).3.5.1.1 after the steel formworks have been promoted, the platform will be applied to carry on the installation of elevator bearers and wires, hanging the steel wires for elevating circular platform, conducting the reinforcement of pulleys through the application of the elevator in the center, and installing of limit device and suspension loops and so forth.3.5.1.2 in prior to the removal of promote platform, the 193m platform will be installed through the application of the jumpform of construction platform. after that, a 2t winch will be lifted to the platform in a appropriate distance of 3-4m to the elevator as the fixing position. the 193m platform will also be utilized to install the 180m platform. and similarly it comes to the 140m one.3.5.1.3 after the promote platform removed, the distribution of cables will be conducted by the utilization of human-and-cargo elevator and cage, as well as installing, fixing and debugging for the winch. meanwhile carry on the installation and welding of suspension points, and steel wire hanging at the 140m platform.3.5.1.4 before the steel liners have been hoisted, a railway rolling chute will be laid in the midst of the preformed hole at the bottom of chimney stack, on which a manpowered vechicle was installed to take the steel liners in place and carry out the upset transportation from the storage yard to the erection position.3.5.1.5 the winch on the promote platform will be employed to fix the welder, winch, and the side basket as the vertical tranporting tools for platform and hydraulic lifting equipments. and in ahead of lowing-down, the installation and welding of lateral bearer, bearers of suspension points and elevator, and guide pulleys on the top must be completed and in preparation.3.5.1.6 the leveling, setting out and embedded items of the pedestal of steel liner should be examined and kept with records to prepare for the febrication and installation.3.5.1.7 preparation for hydraulic lifting equipment: it must be tested and in preparation. there will be one 5t two-tube winch, one 5t winch, one 2t winch, two 3t winches installed and in preparation. the human-and-cargo elevator can be available after it has been debugged and tested with its net load. 3.5.2 operational procedurethe six layers of platforms, straightened ladders, winding stairs, components and embedded items will be manufactured in advance as well as the steel flues will also be febricated at site. the fabrication process is: raw material accessing to the yardverifying the specification and certification of materialcarrying out the stretching , bending, percussion and welding testtemplate-makingfabrication & preparation on the materialalignment of componentsbeing compressed into formationcombination and jointinginspection on the processweldingexamination and alignment for deformational partsmaking holesself-inspection and specilized examinationcleaning up the footing coarse of metaldust removel, oil-painting and corrosion protectionpiling-up and numbering of semi-manufactured products.with the template-making, the sample plates and items must be made, complying with the right shape and dimension and a proportion of 1:1 indicated on the work drawing, and being coodinated with relevant clamping fixture. only after the sample plate has been to transmit to the technical staff and inspector and given by permittion, it can be carried out with its febrication, of which the drawing number, names of components, certification and specification of material must be signed. and preserve enough amount according to different processing measures. for the large sheet material, its geometry dimension, side length and diagonal lines must be controlled and verified, as well as accumulated error considered for the item consists of multiple components. both corrosion protection of final product members and footing course treatment need be in accordance with design and specifications, and make sure the adhensive strength between the membrane and primer. and the painting thickness and layers must be controlled stricktly as well as the material diluted comply with the mixing proportion. the storage yard for steel members must be flat and with no contamination and accumulated water, and the workpieces must be supported firmly with no displacement or sedimentation permitted. numbering must be conducted, and give clear indication of the setting-out line and center line at the same time. for those special ones , their schematic points , names and elevation should be symblolized to facilitate for the verification and transportation. 3.5.2.1 manufacture of steel platform, windingstairs, restraining points and streightened ladders:3.5.2.2 according to the work drawing , the appearance, arc of processing, dimension, and sign number of members accessing to the site must be dealed with examination and acceptance, for which the unqualified ones cannot be put into operation. as a result of special condition, the 193m, 180m, 140m platforms will be elevated and installed in prior to the other three platforms.3.5.2.3 in the reason that all the platforms, steel stairs, fences are final products, there wouldnt be instructions on the manufacturing procedure in these statements.3.5.2.4 each member of the platforms, steel stairs and fences must be marked with the platform and supporting number, and meanwhile the manufacturer should also provide numbered drawings in detail, which was kept to prevent an unnecessary waste of human resources. for instance, the 180m platform should be marked with 180-1, 180-2180-8.3.5.2.5 the hole-making between installation position on the beam and relevant connectors must be conducted by one time. standard joints should be adopted for all the circular and main beams, which cannot be distributed on the center of arc or node. and the structural corrosion protection must be practiced segmentally. for the hiden area, it must be carried out firstly, and the supplemental action must be implemented after welding. welding material and eletrodes must be in accordance with given conditions on quality. for example, e43 series of eletrodes were adopted for a3 steel.3.5.2.6 the fabrication of restraining circular plate should be done comply with the external radius of different tubes.3.5.2.7 for the configuration of pedestal plate, it will be cut on average in accordance with different material. the weld bonds will be staggered as well as foundation bolts compressed. three pieces will be assembled, for which a few weld bonds are preserved to be on the pedestal. the setting-out of holes must be configured strictly with the bolts. the weld bonds of pedestal are single groove, others are double groove, which makes double formation. and before the steel flue was erected, the pedestal must be in position and compressed, numbered with stiffners at support.3.5.2.8 breeching opening and box structure fabrication and assembling: seting out will be carried out previously comply with the dimensions at the opening with signs marked in order to cut-off the opening after the steel flue has been installed.the breeching opening will be made into semi-manufactured product after the template-making has been conducted comply with the drawing. all the plate stiffeners will be distributed around the finished arc reinforcement plates. spot welding will be adopted solely for the plate stiffeners and opening of the box structure. to prevent an influence on the arc deviation, the steel flue can be cut down after it has been laid steadily upon the circular base. install the breeching opening, and later the plate stiffeners will be carried out with the jump welding, with the arc plates welded. in consequence of template-making and batching completed, it will be made into four pieces around the four sides. all the flanges will be fixed with bolts, following the assembly and installation of breeching opening. the base plate will be assembled firstly(spot welding), and later comes to the side plates. and only if making sure that there wasnt something wrong with them, the top plate can be assembled(both side plates has been added with plate stiffeners). for all, attention must be paid that the horizenal seams need be staggered. for the batching of flanges, interfaces of large ones must be assembled in pairs with the hole-making, for which it will be numbered and stored later. to prevent the deformation from the welding, the spot welding will be conducted additionally at the opening, and the adjustment can be carried out after it has been cooled. setting-out of breeching opening and box structure must be implemented and marked to facilitate for the cutting. the box structure will be cut in sections and installed on site. the assembling clearance will be 46mm with plug welding.3.5.3 steel liner fabrication the raw material should be examined before the members have been processed, and certificate of qualification must be received for steel and eletrodes. the surfacial defects of material must be treated before processing, with no flaws on the edge or surface. and the next procedure can not be carried out until the previous one has been completed.3.5.3.1 sheet material preparation: in accordance with its circumference, it will be divided into three pieces on the platform in front of plate roller , which will be cut into a rectangle by automatic cutting machine with an accurate length and uniform diagonals to ensure the dimension and vertical error can be allowed within the limitation. and according to the drawing , its required to preserve grooves which needs be finished by polishing machine.3.5.3.2 rolled plate cutting: two semi-automatic cutting machines will be adopted to carry on the trimming and cutting, in order to avoid the deformation. one will be utilized to cut the straight flange, and another for the groove. two cutting machine must work simultaneously. 3.5.3.3after the cutting has been finished, the openning must be treated with grading.3.5.3.4the steel plates with no errors identified will be lifted by a gantry crane into the roller to form into a cylinder ,complying with the designed diameter. firstly try ,and then find the arc. when the arc meets the requirement, it needs be rolled up in one time, of which the error of each plate cannot exceed 1mm, and accumulated error of every three plates cannot exceed 3mm. 3.5.3.5 in order to reduce the welding seams and speed up the progress, five clamping frames should be prepared on the site, of which the pedestal must be leveled. the steel flue sections will be encloured and welded on the second frame(that is the assembly of 1.5m steel flue sections). and for the 3m steel flues, they will be conducted on the other two clamping frames, as well as the last one for the 6m flue. in the process, the longitudinal seam should be staggered mutually, which cannot be less than 300mm. to ensure a reliable circumference, it can be collated through the test assembling of plates in batch. and in order to keep the seams of lap joint in quality, the welding can be operated on the scaffolding, for which it should be continuous and no intervals permitted. for every single flue completed, over-night longitudinal seams were not allowed to left, and over-spot-welding was prohibited. to implement the regulations, the horizental seams were level one, and longitudinal seams were level two. the heaping of welded seams can be within an error of 1.51.0mm, concave value 0.5mm, as well as staggered distance 1mm. and the heavy hitting must be avoided in the process of assembly.3.5.3.6 to ensure the concentricity of steel flues, the collar extensions with the same circumference must be flat for the assembly, and the staggering error must be controlled strictly within the limitation of specification. to achieve an accurate and reliable erection, the opening must be divided into eight parts equally. the whole process will be initiated from top to buttom, in which the each section must be marked with number, elevation and bisectrixes, to prevent the slap staggering of vertical seams. 3.5.3.7 steel liner sections assembling: for the 1.5m section, make sure that its grooves were downward with the faces outward. with the face of no groove upward, firstly two sections will be combined in one segment, and two segments will be assembled into one flue. and finally two flues will also be jointed together and meanwhile installed with reinforced rings. the steel liner assembly will be conducted with priliminary centering by a micrometer and then added with the snap-gauges. after that, it will be fixed with spot welding.the angle steel tripods will be spot-welded on the outside shell to facilitate the assembly. and the planks with thickness of no less than 50mm will be paved on the tripods.3.5.3.8 after the steel flues have been assembled,with no errors examined, it can be started to weld the collar extensions, which must be implemented strictly in accordance with the requirements of design and specification. the welders must operate on it with certificates. polishing machine and carbon arc gouging will be adopted for both weld bond cleanning and substrate treatment, and each final product must be numbered according to the diagram of components.3.5.3.9 when the steel flues were made into the 6m one, its necessary to carry on the grit-blast and corrosition protection treatment, to reduce the working in high and speed up the erection progress. 3.5.3.10 special flue farication: after the first flue has been made on the construction platform, carry on the installation and welding of stiffened angle steel and steel flat, and later comes to the installation and welding of the outside stainless steel cover in accordance of the requirements of drawing. please review the diagram for the fabrication of other steel flues which need be installed with ring stiffners or suspension points.3.5.4 erection procedureorder of erection: all platforms of steel stair193m platform 180m platform140m platform140m suspension point operation platformhydraulic elevation hanger frame and equipments installationno. 134 steel flues liftingrestraining points installation of 140m platform105m platform70m platform and restraining points installation35m platform193m, 180m platforms and restraining points installationelevator installationstainless steel canopy installationborosilicate blocks installation.3.5.4.1 hoisting and installation of structurea. applying with the circular platform and transit instument at the centeral bottom of chimney, the platform bearers will be positioned by dividen degrees. and a long ruler will be utilized to mark the correct installation elevations of platforms of all layers, as well as a vertical mirror is employed to review the center line, from which the position of main beam can be identitfied. after the elevation of main beam terminal bearers has been verified with no errors, it can be conducted with the earth plate installation, welding, presentational treatment and additional painting.b. first platform erection(+193 m): as the promoting of form completed, all the members will be delivered to the platform by derrick masts being moved vertically and installed one by one. to be in order, the installation of bearers will be prior to lateral beams, as well as horizental beams to the strutting pieces, and finally comes to the board paving. by catching up with the installation of horizental beams, the elevator support and steel wires will be installed, and hoisting holes will be preformed on the platform.c. install the embedded items in the 195m chimney windshield with specialized scaffoldings, which will be taken as the supporting points to hoist the members. d. due to a special hoisting process, the 193m,180m,140m platforms and hydraulic gantry will be installed previously. after the lifting of steel liners has been completed, the same method will be taken to install the surplus three platforms by cage. and the platforms of all layers on the steel stairs will be installed along with the jump platform.3.5.4.2.1 lifting equipments a. selection of lifting equipments: as a consideration of current lifting capacity, the lifting method will be taken for the steel liners. in detail, the chimney flue will be divided into thirty-four setions which will be elevated in one time to complete the installation. four center-hole jacks will be deployed as the main hoisting equipment, with a lifting weight of 200t per one.b. perfomance parameters of hydraulic lifting equipments:a：elevating jack typelsd2000d rated oil pressure28mpa elevating force2000kn area of lifting piston mm2(10-2)7.34 hysteresis piston area mm2(10-2)5.26 center-hole diameter170mm presentational dimension5501200mm stroke300 mm lifting speed3.42m/h jacking pressure92 kn steel strand diameter15.24mm quantity of steel strands10 weight850kgb：pump station typetzb2032 rated pressure31.5mpa rated discharge21.48l/minc：steel strands diameter15.24/mm2 strength level1860n distructive load260.7kn quantity of steel strands12 pieces per one quantity of total steel stands48 pieces3.5.4.2.2 principles of lifting: the suspension points will be arranged at the +173m and 123m elevation of steel flue, and four 200t hydraulic jacks will be installed at the 140m windshield, which are connected with steel strands. and in the process of running,the hydraulic jack lifts the ste