1. Field Of The Invention
The present invention relates to an inspection scaffold of large components for a boiler and a building method thereof, and particularly relates to the inspection scaffold and the building method thereof to perform pressure tests and the other inspection works of boiler superheater coils placed at a thermal power station.
2. Description of Related Art
Generally, a steam generating equipment of a thermal power station includes a burner, a furnace, a pendant coil group such as a superheater and a reheater, and these are stored inside of a large building. In such a facility, the pendant coils such as the superheater and the reheater are positioned at an upper portion of a boiler, and they are suspended and supported by a main-beam positioned particularly at a top end surface of a steel frame structure constituting a power station building. An assembling construction method is adopted for equipments including particularly a coil to be a steam passage positioned at the upper portion of the boiler such as the superheater, in which they are assembled at a factory and so on by each equipment, carried in the steel frame, lifted by each equipment by using a lifting equipment to suspend and fix to the main-beam, disposed and equipped at a predetermined position, and thereafter assembly items are assembled with each other. After the assembling of power generating equipments is completed finally, a hydraulic test is performed by passing water. Herewith, it is necessary to perform defect inspections and repair works of welded portions of the coil, and therefore, the inspection works at every portion of the coil are required. Consequently, the inspection scaffold of a large component such as the superheater is assembled, and it is a temporary scaffold which is removed after predetermined tests and inspections are finished.
The above-stated conventional inspection scaffold is used for the test after the facility is settled, and therefore, it is attached after the power station equipments are assembled. Consequently, the scaffold is assembled and attached around the coil by a high-place work at dozens of meters upward because the large components such as the superheater including these coils are positioned at a high place at the upper portion of the boiler.
As such kind of scaffold, for example, a scaffold described in Patent Document 1 is used. A suspended scaffold described in this Patent Document 1 is suspended from a boiler main body structure, having a horizontal rigid member to be the scaffold at a top layer, the scaffold of a second layer is composed of two pairs or more of perpendicular rods coupled attachably/detachably to the corresponding horizontal rigid member, horizontal rods provided with flanges at both ends and bridged attachably/detachably between the above-stated paired perpendicular rods,. and a scaffold board bridged between the corresponding horizontal rods, the scaffold of a third layer or later is composed of the perpendicular rods, the horizontal rods and the scaffold boards as same as the second layer, and it is the suspended scaffold within a boiler furnace in which the perpendicular rods are attachably/detachably suspended to the horizontal rods of an upper layer. The above-stated scaffold is provided on a wall surface around a peripheral surface inside of the boiler furnace, and it is assembled around the coil at a high place by the same method.
However, conventionally, as stated above, the building of the scaffold is a high-place work and the scaffold is built after the power station facility is assembled. Consequently, components other than the coil being an inspection object are existing around the coil, and therefore, there is a problem that the assembling work of the scaffold is very difficult. In particular, in the superheater, a lot of narrow coils are coupled to headers, this is vertically disposed in a structure well-ordered in a plane state, and equipped in a lot of lines with narrow intervals, and therefore, there are also problems that the work for the scaffold assembling is difficult and the time required for the assembling is extremely long.
[Patent Document 1] Japanese Patent Application Laid-open No. Sho 59-044504
The present invention has an eye on the above-stated conventional problems, and an object thereof is to provide an inspection scaffold and a building method capable of assembling the scaffold safely without performing the scaffold assembling of a large component for a boiler requiring inspections in a high-place work. Secondly, the object thereof is to provide a building method capable of drastically shortening hours of work for the assembling of the scaffold. Thirdly, the object thereof is to provide an inspection scaffold and a building method capable of assembling a power station while the scaffold in itself has a protective function of attendant structures of the large component.
To attain the above-stated objects, a building method of an inspection scaffold of a large component for a boiler, including: suspending a scaffold lifting/supporting beam interposing in a space of the large component on a wire lifted down from a space of a horizontal member of the large component, to the large component for the boiler supported by a component supporting beam at the ground side before it is attached to a steel frame main-beam; assembling scaffold components sequentially toward downward while the scaffold lifting/supporting beam is lifted to raise little by little inside of the large component; coupling the scaffold lifting/supporting beam to the horizontal member of the large component to be supported, after a required number of steps of scaffolds are assembled; and building the inspection scaffold together with the large component by raising the large component by a lifting means to couple to the main-beam.
In the above-stated method, the scaffold is constituted by raising each scaffold unit composed of the scaffold lifting/supporting beams, rods coupled to a lower surface side thereof, and scaffold boards, coupling to the horizontal member of the large component, and thereafter, coupling the scaffold units with each other to be integrated.
Besides, the large component is a pendant coil, and plural lines of coil groups, formed by arranging narrow tubes in similar shapes on respective headers in one plane state, are regarded as one block, and the scaffold unit is assembled by each block.
Further, the large component is a superheater, and the horizontal member is a ceiling tube wall.
An inspection scaffold of a large component for a boiler, including: scaffold lifting/supporting beams interposed in spaces of the large component; horizontal and perpendicular rods at least forming scaffold frames at a lower surface portion of the scaffold lifting/supporting beams and capable of being coupled with each other; and scaffold boards bridged between the horizontal rods at the spaces, and wherein required number of steps of the scaffold boards can be sequentially assembled at a lower surface of the scaffold lifting/supporting beam, and wherein the scaffold lifting/supporting beam has a coupling means with a horizontal member of the large component and capable of being suspended and supported by the large component.
Besides, more concretely speaking, it is an inspection scaffold of a large component for a boiler, which is assembled to a pendant coil constituted by arranging plural coil groups perpendicularly in which plural narrow tubes are arranged along a plane surface, including: scaffold lifting/supporting beams capable of raising/lowering at spaces of the coil groups, and capable of coupled and supported by a part of a ceiling tube wall of the pendant coil; perpendicular rods and horizontal rods supported at a lower surface of the lifting/supporting beam and capable of being coupled with each other; and scaffold boards capable of bridged between the horizontal rods, and wherein the inspection scaffold is capable of integrally assembled to the pendant coil while suspended and supported by the ceiling tube wall of the pendant coil.
As having such a constitution, in the present invention, the scaffold is assembled to the large component before installed to the boiler at the power station by each scaffold unit, the scaffold units are coupled with each other and integrated with the large component, and thereafter, the large component is lifted to the steel frame main-beam, and fix to the main-beam. Herewith, an assembling work of attendant equipments to the large component and the scaffold assembling can be simultaneously performed at the ground, and therefore, hours of work for the scaffold assembling can be eliminated drastically, and at the same time, an effect of an enhanced safety in the work can be obtained because it is not a high-place work. The respective scaffold units are disposed at spaces of the large component, and therefore, it has a block structure as a whole, and a merit of preventing a risk of a crash caused by a rolling of each suspended structure of the large component can be obtained. In particular, it is applied to the pendant coil, in which perpendicular coil lines are in a suspended state, and even if a bending force or the like acts, but they are blocked, and therefore, a protective function can be exerted owing to a frame structure of the scaffold composing member.
Hereinafter, an optimal embodiment of an inspection scaffold of a large component for a boiler and a building method thereof according to the present invention is described with reference to the drawings.
At first, in
In a power station having large suspending type boilers, a main-beam 16 for supporting the boilers is provided at a top end portion of a steel frame to be a suspending fabric, and boiler components are supported in a state suspended by this main-beam 16. Plural lifting jacks are placed on the main-beam 16, a block of the boiler components carried in the steel frame is lifted up to the main-beam 16 by using the lifting jacks, and it is supported and suspended by the main-beam 16 by using a sling rod and so on. These works are sequentially repeated from assembling components of an upper portion of the boiler to thereby build up the boiler. Attendant equipments are assembled to the boiler components block at the ground work or in the middle of a lifting operation, and this assembling work of the attendant equipments is often performed in a state supported by a component supporting beam provided at the ground side. In the present invention, the inspection scaffold 20 of the large component is simultaneously assembled together with the assembling of the attendant equipments in a state the large component of the boiler components is suspended to the component supporting beam at the ground.
The assembling work of the inspection scaffold 20 according to the present embodiment is performed to the third superheater 14 as the large component for the boiler supported by the component supporting beam 30 at the ground side under the steel frame main-beam 16, as follows. At first, scaffold lifting/supporting beams 32 interposing in spaces between coil lines of the corresponding third superheater 14 are coupled to wires 36 lifted down from spaces of a ceiling tube wall 34 being a horizontal member of the third superheater 14 to suspend down close to a floor surface. This scaffold lifting/supporting beams 32 are lifted to raise little by little in the spaces of the coil group within the third superheater 14, and the scaffold components are assembled sequentially toward downward. After a required number of steps of the scaffolds are assembled, the scaffold lifting/supporting beams 32 are coupled to be supported to the ceiling tube wall 34 of the large component for the boiler, the third superheater 14 is raised by the lifting jacks to couple to the main-beam 16, to thereby build the inspection scaffold together with the large component.
At first, as a basic constitution of the inspection scaffold, there are the scaffold lifting/supporting beams 32 suspended on the wires 36 (refer to
A shape of the potbelly shaped hole 40B is described in more detail, a semicircular portion of the small-diameter hole 40D and the large-diameter hole 40C are connected by a parallel groove having an equal width with the diameter of the small-diameter hole 40D, and the bar portion 42B of the horizontal rod 42 is movable between the large-diameter hole 40C and the small-diameter hole 40D.
Besides, the spaces between the two pieces of flanges 42A, 42A respectively attached at both ends of the horizontal rod 42 are slightly larger than a double of a thickness of the coupling board 40A attached at the both ends of the perpendicular rod 40.
The flange 42A of the horizontal rod 42 is inserted from the large-diameter holes 40C of the coupling board 40A at a lower end of the perpendicular rod 40 suspended from an upper layer and the coupling board 40A at an upper end of the perpendicular rod 40 to be suspended to a lower layer respectively, and they are engaged to the respective small-diameter holes 40D with the bar portion 42B at the space between the two pieces of flanges 42A, 42A. A gripper 46 for gripping the bar portion 42B of the horizontal rod 42 engaged with the respective small-diameter holes 40D is provided at the coupling board 40A of the upper end of the perpendicular rod 40.
Between the horizontal rod 42 and the adjacent horizontal rod 42 bridged to the paired perpendicular rods 40 of each layer, the scaffold board 44 is bridged by engaging the hooks 44C, 44C provided at the both ends in the longitudinal direction thereof with the horizontal rods 42, to be the scaffold of each layer.
In the scaffold having such a basic constitution, in the present embodiment, plural lines of coil groups are regarded as one block, which are formed by arranging narrow tubes 50 in similar shapes in a plane state at respective headers 48 positioning at an upper end of the superheater 14, and scaffold units are assembled by each block. Namely, as shown in
By the way, the ceiling tube wall 34 is provided at an upper position of the superheater 14 to horizontally cross the coil groups, in which a number of ceiling tubes are thickly arranged in plane state, and the ceiling tubes are coupled with each other by membrane bars. Consequently, the ceiling tube wall 34 becomes a horizontal member of the superheater 14, so the above-stated scaffold is assembled to this ceiling tube wall 34 as a mounting base end.
A concrete attaching procedure of the scaffold is described in detail with reference to
As stated above, the scaffold lifting/supporting beam 32 suspended on the wire is once lifted down near to the floor surface of the moving jack stand 28, the perpendicular rods 40, the horizontal rods 42 as the scaffold composing members are assembled to this, and the scaffold board 44 is bridged between the pair of the horizontal rods 42 to perform the assembling of the scaffold at the first stage. Herewith, the scaffolds are built in the spaces of the coil group within the superheater 14. The scaffold lifting/supporting beam 32 is lifted to raise little by little, and the scaffold components are assembled sequentially toward downward to assemble the required number of steps of the scaffolds, as shown in
As shown in
As stated above, the scaffold is assembled integrally with the superheater 14 and fixedly supported. As shown in
As stated above, in the present embodiment, at a stage before the superheater is attached to the main-beam 16, in particular, when it is carried in the steel frame of the power station, the scaffold lifting/supporting beams 32 capable of raising/lowering in the spaces of the coil groups of the corresponding superheater 14 are disposed as the ground work, and in a state that they are suspended on the wires 36 penetrating the ceiling tube wall 34 of the superheater 14, the scaffold composing members can be sequentially assembled to a lower surface of the supporting beams 32 by the ground work. When the scaffold assembling of required number of steps is completed, the scaffold lifting/supporting beams 32 are coupled to the ceiling tube wall 34 by using the strip-plates 58 and the receiving beams 62 as coupling means. Herewith, the scaffold is supported by the superheater 14 in itself. The plural scaffold units 51 are coupled mutually by the coupling scaffold boards 60, and then the entire inspection scaffold 20 is integrally blocked with the superheater 14 to thereby install the superheater 14 together with the scaffold to the main-beam 16.
Incidentally, in the above-stated embodiment, an example applied to the third superheater 14 is described, but the present invention can be applied to the second superheater 12 and to the equipments having the other pendant coils.
From these reasons, in the present embodiment, it is possible that the scaffold assembling for the pendant coil as the large component for the boiler requiring inspections is not performed at the high-place work, but assembled safely. Besides, the scaffold assembling is performed at the ground work, so the inspection scaffold is simultaneously built when the pendant coil is installed to the main-beam, and therefore, the hours of work for the scaffold assembling can be reduced drastically. Further, the scaffold in itself is placed so as to embed the spaces of the pendant coils, and therefore, it is possible to assemble the power station while a protective function for the attendant structures of the pendant coil is added to the scaffold.
Number | Date | Country | Kind |
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2005-272371 | Sep 2005 | JP | national |
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Number | Date | Country | |
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20070074934 A1 | Apr 2007 | US |