Hanging type boiler barrel hoisting method

Abstract

The invention discloses a hanging type boiler barrel hoisting method which comprises the following steps: selecting a boiler barrel temporary placing beam below a boiler barrel hanging device, and mounting a boiler barrel saddle on the temporary placing beam; the installation direction and levelness of the boiler barrel are adjusted on the ground, then the boiler barrel is fixed to the hoop, and the boiler barrel is hung to the boiler barrel saddle; hoisting the large plate girder and the hoisting rod in place, and connecting the hoisting rod with the hoop through a pin shaft; and finally, the boiler barrel saddle is dismantled, and the boiler barrel is formally hung in place. The saddles with the same elevation and installation center line are arranged below the boiler barrel hanging device, the boiler barrel is leveled on the ground in advance, the problem that the elevation, the longitudinal and transverse center lines and the longitudinal and transverse level of the boiler barrel in the hanging device are difficult to adjust is solved, and the installation precision and efficiency of the boiler barrel are improved. And in the hoisting process, high-altitude and near-edge operation of constructors is reduced, and potential safety hazards are reduced.

Description

Technical Field

[0001] This invention relates to the field of equipment hoisting in power construction projects, and more specifically, to a method for hoisting a hanging boiler drum. Background Technology

[0002] Boiler drum hoisting is a core part of boiler installation, involving significant weight and high installation precision (horizontal and horizontal level deviation ≤2mm, center position deviation ±5mm, elevation deviation ±5mm). It involves the selection of large hoisting equipment, site layout, and safety control technologies. Based on the weight and size of the boiler drum, high-tonnage crawler cranes or truck cranes must be selected for hoisting to ensure the equipment's load-bearing capacity meets requirements. The cranes must possess high-precision positioning and stability to avoid safety accidents caused by insufficient equipment performance.

[0003] There are two main traditional hoisting methods: The first involves hoisting the boiler drum to the bottom of the furnace, then installing two winches on the boiler drum hoisting beam. Because the length of the boiler drum is greater than the width of the furnace, the two winches need to alternately tilt and lift the boiler drum before finally hoisting it into place. This process requires multiple alternations, resulting in low hoisting efficiency, numerous safety hazards, and potential damage to the internal components of the boiler drum during hoisting, affecting its operation. The second method involves hoisting the boiler drum to its installation position after the beam and boom are in place, then connecting the clamps to the boom and hoisting it into place. Both of these methods are inefficient, involve a lot of work at height, and pose numerous safety hazards. Therefore, the choice of hoisting method directly determines the accuracy and difficulty of the boiler drum hoisting. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a hanging boiler drum hoisting method to improve the installation accuracy, efficiency and safety of the boiler drum.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is: a method for suspending a hanging boiler drum, comprising: Step 1: Select a temporary beam for placing the boiler drum below the boiler drum hanging device; Step 2: Install the boiler drum saddle on the temporary placement beam; Step 3: Adjust the installation position and level of the boiler drum on the ground and then fix it to the clamps; Step 4: Hoist the boiler drum onto the boiler drum saddle. Step 5: Hoist the large beam and hangers into place, and connect the hangers and clamps with pins; Step six: Remove the boiler drum saddle, and the boiler drum is officially hoisted into place.

[0006] Furthermore, in step one, the beam at an elevation of 22.3m directly below the boiler drum hanging device is selected as the temporary placement beam for the boiler drum.

[0007] Furthermore, in step one, the strength of the temporary placement beam is checked to see if it meets the requirements for placing the boiler drum, based on the weight of the boiler drum and the specifications of the temporary placement beam. If it does not meet the requirements, temporary supports are welded under the temporary placement beam to reinforce it.

[0008] Furthermore, in step two, the boiler drum saddle includes a saddle base plate, a saddle stiffening plate, a saddle top plate, and a saddle plug plate. The saddle stiffening plate is fixed between the saddle base plate and the saddle top plate, and the saddle plug plate is fixed to the rear edge of the saddle top plate. The saddle plug plate has an arc-shaped surface that matches the arc surface of the boiler drum.

[0009] Furthermore, the saddle stop plate includes two stop plates respectively disposed at both ends of the rear edge of the saddle top plate, each stop plate having an arc-shaped surface, and the arcs of the two stop plates being arranged opposite each other.

[0010] Furthermore, in step three, the installation orientation of the boiler drum is determined based on the orientation of the boiler drum inlet, and leveling is achieved using the method of connecting horizontal pipes.

[0011] Furthermore, in step four, when the boiler drum is hoisted onto the boiler drum saddle, the clamp is positioned in the contact area between the boiler drum and the boiler drum saddle.

[0012] The hanging boiler drum hoisting method according to claim 7 is characterized in that: in step six, the installation elevation and center line of the boiler drum are positioned before the boiler drum is placed in place.

[0013] This invention solves the problem of difficulty in adjusting the boiler drum's elevation, longitudinal and transverse center lines, and horizontal alignment within the suspension device by setting a saddle at the same elevation and installation center line below the boiler drum suspension device, allowing the boiler drum to be leveled on the ground beforehand. This improves the accuracy and efficiency of boiler drum installation. The hoisting process also reduces the need for workers to operate at heights and near edges, thus minimizing safety hazards. Attached Figure Description

[0014] The accompanying drawings, which are provided to further illustrate the invention and form part of this application, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention.

[0015] Figure 1 This is a schematic diagram of the hanging boiler drum hoisting and positioning according to the present invention; Figure 2 This is an isometric view of the boiler drum saddle of the present invention; Figure 3 This is a schematic diagram of the crane station location for the present invention; Figure 4 This is a schematic diagram of the crane lifting operation of the present invention.

[0016] In the diagram, 1 is the temporary beam, 2 is the boiler drum saddle, 3 is the clamp, 4 is the hanger, 5 is the boiler drum, 6 is the large plate beam, 2-1 is the saddle base plate, 2-2 is the saddle stiffening plate, 2-3 is the saddle top plate, and 2-4 is the saddle insert plate. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present invention, the present invention will be further described clearly and completely below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0018] The hanging boiler drum of the present invention is suspended below the large plate beam 6 in front of the furnace by a hanging device. The basic concept of the present invention is to connect the hanging rod and the clamp after adjusting the installation elevation, longitudinal and transverse center lines and longitudinal and transverse levelness of the boiler drum, and then suspend the boiler drum.

[0019] Based on the above inventive concept, a typical embodiment of the present invention provides a hanging boiler drum hoisting method, which includes the following steps one to six.

[0020] Step 1: Select a temporary placement beam 1 for the boiler drum below the boiler drum hanging device.

[0021] The temporary placement beam 1 is located directly below the hanger 4. The strength of the temporary placement beam is checked according to the weight of the boiler drum and its specifications. If it does not meet the requirements, temporary supports are welded under the temporary placement beam to reinforce it.

[0022] Step 2: Install the boiler drum saddle 2 on the temporary placement beam 1.

[0023] like Figure 2 As shown, the boiler drum saddle 2 includes a saddle base plate 2-1, a saddle stiffening plate 2-2, a saddle top plate 2-3, and a saddle plug plate 2-4. The saddle stiffening plate 2-2 is fixed between the saddle base plate 2-1 and the saddle top plate 2-3. The saddle plug plate 2-4 is fixed to the rear edge of the saddle top plate 2-3. The saddle plug plate 2-4 has an arc-shaped surface that matches the arc surface of the boiler drum 5.

[0024] The height of the boiler drum saddle 2 is calculated based on the installation center elevation of the boiler drum 5, the top elevation of the temporary placement beam 1, and the height of the clamp 3. The corresponding boiler drum saddle 2 is then manufactured according to the boiler drum specifications and welded onto the temporary placement beam 1 described in step one.

[0025] Step 3: Adjust the installation position and level of the boiler drum on the ground and then fix it to the clamp.

[0026] The boiler drum is secured to the clamps using a hand chain hoist. The installation orientation of the boiler drum is determined based on the orientation of the boiler drum inlet, and leveling is achieved using the horizontal pipe connection method.

[0027] Because the level gauge is installed in front of the furnace, the side of the boiler drum with the level gauge interface is in front of the furnace, and the other side is behind the furnace.

[0028] The principle of using the connected horizontal pipe method for steam drum leveling is based on the principle of communicating vessels. When both ends of the horizontal pipe are open and the bottom is connected, the internal liquid level will remain horizontal. The same height at both ends is determined by observing whether the liquid levels are consistent. Specific operating steps: 1. Prepare tools: Use a transparent plastic tube with openings at both ends and ensure the bottom is connected.

[0029] 2. Water filling test: After filling the water pipe with water, two people hold both ends of the pipe and move it to the position where leveling is required.

[0030] 3. Judgment criteria: If the liquid levels at both ends are the same, it means that the two heights are the same; if the liquid levels are different, the height difference needs to be adjusted until the liquid level is horizontal.

[0031] Step 4: Hoist the boiler drum 5 onto the boiler drum saddle 2.

[0032] The boiler drum 5 is lifted onto the boiler drum saddle 2 using a 300t truck crane. The clamp 3 is located in the contact area between the boiler drum 5 and the boiler drum saddle 2 to prevent local plastic deformation.

[0033] Step 5, as Figure 1 As shown, the large plate beam 6 and the hanger 4 are hoisted into place, and the hanger 4 and the clamp 3 are connected by a pin.

[0034] Step 6: Remove the boiler drum saddle 2, and the boiler drum 5 is officially hoisted into place.

[0035] The technical solution claimed in this invention will be further clearly and completely described below through a relatively specific embodiment.

[0036] This embodiment involves the hoisting of two 110t / h gas-fired boiler drums. The drum 5 has an inner diameter of Φ1600mm, a wall thickness of 100mm, a straight section length of 7.8m, a total length of 9.67m, is made of P355GH steel plate, weighs 43.376t, and is installed at an elevation of 23.75m. The numerous overlapping operations on site, limited hoisting space, and the heavy weight and high installation precision of the boiler drums presented significant challenges to the hoisting operation.

[0037] Selection of temporary placement beam 1 for boiler drum The beam at an elevation of 22.3m directly below the boiler drum suspension device (No.: G-GL52, 200×300 mm, 5m long) was selected as the temporary placement beam 1 for the boiler drum. The strength calculation of the beam is as follows: (1) Load calculation Weight of the boiler drum: P = 433.76 kN (gravitational acceleration is taken as 10 m / s²) 2 ); Uniformly distributed load: Each beam bears P / 2 = 216.88 kN; Line load: .

[0038] (2) Calculation of cross-sectional properties Box-shaped cross-section dimensions: 200 (width) × 300 (height) × 12 (wall thickness); Cross-sectional area: A = 2 × (200 × 12) + 2 × (300 - 2 × 12) × 12 = 11040 mm 2 ; Moment of inertia: ; Section modulus: .

[0039] (3) Strength verification Maximum bending moment (for a simply supported beam under uniformly distributed load): ; Bending stress: .

[0040] The design value of the bending strength of Q355B steel is ƒ=295MPa according to the specification (GB-50017).

[0041] Verification: 121.0MPa < 295MPa, which meets the requirements.

[0042] Deflection verification Allowable deflection: usually taken as ; Actual deflection: ; Verification: 10.2mm < 20mm, which meets the requirements.

[0043] Conclusion: The strength and stiffness of both beams meet the requirements and can safely withstand the boiler drum load of 43.376t.

[0044] Boiler drum saddle fabrication and installation Based on the boiler drum installation center elevation line of 23.75m, the clamp height of 0.15m, the boiler drum outer diameter Φ1.8m, and the beam elevation of 22.4m, the boiler drum saddle height is determined as: h = 23.75 - 0.8 - 0.15 - 0.9 - 22.4 = 0.4m. The saddle is 1m long and 0.3m wide.

[0045] The boiler drum saddle 2 is made of 20mm thick Q355B steel plate, such as Figure 2 As shown, the boiler drum saddle 2 includes a saddle top plate 2-3 (300×1000×20mm), a saddle bottom plate 2-1 (300×1000×20mm), a single vertical stiffening plate in the middle (400×1000×20mm), and eight horizontal stiffening plates (140×400×20mm). The saddle stopper plate 2-4 is fabricated by laying out the circular end face of the boiler drum clamp, and its arc surface can fit with the arc surface of the boiler drum 5 to ensure that the boiler drum 5 will not rotate when placed on the boiler drum saddle 2. The saddle bottom plate 2-1 is welded to the temporary placement beam section 1.

[0046] The strength calculation of boiler drum saddle 2 is as follows: (1) Load calculation Total weight of boiler drum: 433.76kN (uniformly distributed, with the saddle bearing approximately 216.88kN on one side). Saddle weight: Upper / lower base plates: 2 pieces × (0.3m × 1m × 0.02m) × 78.5kN / m³ ≈ 0.942kN; Vertical stiffening plate: 1 piece × (0.4m × 1m × 0.02m) × 78.5kN / m³ ≈ 0.628kN; Transverse stiffening plate: 8 pieces × (0.14m × 0.4m × 0.02m) × 78.5kN / m³ ≈ 0.704kN; Total weight ≈ 2.274kN (single-sided saddle).

[0047] Total load (single-sided saddle): 216.88kN (boiler drum) + 2.274kN (self-weight) ≈ 219.154kN.

[0048] (2) Strength verification 1) Bearing capacity calculation of the base plate The area under pressure is: the area of ​​the bottom plate = 300mm × 1000mm = 300000mm²; Pressure: 219.154kN / 300,000mm²≈0.73MPa, far below the compressive strength of Q355B (design value approximately 305MPa), safe.

[0049] 2) Vertical stiffening plate stability The aspect ratio is 400mm in height and 20mm in thickness, which equals 20. This must meet the local stability requirements of Q355B (the specification limit is usually ≤). (≈32.8), which satisfies the condition; Buckling check: Calculated as a simply supported plate at both ends, the critical stress is much higher than the actual stress, which is safe.

[0050] 3) Weld strength Fillet weld (8mm weld leg): Total weld length (taking vertical stiffener as an example): 2 × 1000 mm = 2000 mm; Shear bearing capacity of weld: 0.7×8mm×2000mm×160MPa (Q355B weld design value)≈1792kN≫219.154kN, safe.

[0051] (3) Stiffness and local stress The function of the horizontal stiffening plates is to prevent the vertical stiffening plates from becoming laterally unstable; a spacing of 140mm is reasonable.

[0052] Local stress concentration: The contact area between the boiler drum 5 and the boiler drum saddle 2 is transitioned by a clamp 3 with a rounded arc to avoid local plastic deformation.

[0053] Conclusion: The current saddle design meets the requirements in terms of both strength and stability.

[0054] Selection of steel wire rope for boiler drum hoisting The selected wire rope is Φ48mm, model 34×7+FC, consisting of two 4-strand ropes, each 24m long. Referring to Table 9 of GB8918-2006 "Important Purpose Wire Ropes," the minimum breaking strength of a single rope is 988KN. Based on the stress calculations for the main crane: The safety factor of the wire rope is n1 = 988 × 4 × 1000 / (51000 × 10) = 7.75 > 6; The safety ratio is greater than 6 times, which meets the requirements of the standard SY-76279-2016 "Safety Regulations for Lifting Large Equipment".

[0055] Determination of crane and station location for boiler drum hoisting The boiler drum has a net weight of 43.376 tons and an installation elevation of 23.75 meters. A 300-ton truck crane will be used for lifting, with a main boom length of 49.8 meters, a lifting radius of 14 meters, and a lifting capacity of 58 tons. The crane position is as follows... Figure 3 As shown, two cranes are positioned on either side of the boiler, and a temporary storage point for the boiler drum is set up near the cranes' positions.

[0056] Stress calculations when using a 300t truck crane for lifting: Based on: P = (F + q) × K; P: Lifting load; F: Weight of the boiler drum; q: The total weight of lifting gear and rigging is 2.98652t (hook: 1.443t + rigging 0.24352t + clamp 1.3t); K: Dynamic load factor, taken as 1.1; Therefore, P = (43.376 + 2.986) × 1.1 = 51t Crane load rate: η=51 / 58×100%=88%<100%, which meets the construction safety requirements.

[0057] Before hoisting the boiler drum, determine its position and level it, then secure it to the clamps. First, determine the installation position of the boiler drum based on the orientation of the boiler drum inlet. Level the drum using the horizontal pipe connection method. Then, use a hand-operated hoist to fix the clamp to the boiler drum hoisting position.

[0058] The boiler drum was lifted onto a temporary mounting saddle using a 300t truck crane, such as Figure 1 , 4As shown. After the boiler drum 5 is hoisted into place, the large plate beam 6 and the hanger 4 are then hoisted into place.

[0059] Then, the boom and clamp are connected by a pin, and finally the saddle is removed, and the boiler drum is officially hoisted into place.

[0060] The scope of protection claimed by this invention is not limited to the specific embodiments described above. For those skilled in the art, this invention can have various modifications and alterations. Any modifications, improvements, and equivalent substitutions made within the concept and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for suspending a hanging boiler drum, characterized in that, include: Step 1: Select a temporary beam for placing the boiler drum below the boiler drum hanging device; Step 2: Install the boiler drum saddle on the temporary placement beam; Step 3: Adjust the installation position and level of the boiler drum on the ground and then fix it to the clamps; Step 4: Hoist the boiler drum onto the boiler drum saddle. Step 5: Hoist the large beam and hangers into place, and connect the hangers and clamps with pins; Step six: Remove the boiler drum saddle, and the boiler drum is officially hoisted into place.

2. The hanging boiler drum hoisting method according to claim 1, characterized in that: In step one, the beam at an elevation of 22.3m directly below the boiler drum hanging device is selected as the temporary placement beam for the boiler drum.

3. The hanging boiler drum hoisting method according to claim 1, characterized in that: In step one, the strength of the temporary placement beam is checked to see if it meets the requirements for placing the boiler drum, based on the weight of the boiler drum and the specifications of the temporary placement beam. If it does not meet the requirements, temporary supports are welded under the temporary placement beam to reinforce it.

4. The hanging boiler drum hoisting method according to claim 1, 2 or 3, characterized in that: In step two, the boiler drum saddle includes a saddle base plate, a saddle stiffening plate, a saddle top plate, and a saddle plug plate. The saddle stiffening plate is fixed between the saddle base plate and the saddle top plate, and the saddle plug plate is fixed to the rear edge of the saddle top plate. The saddle plug plate has an arc-shaped surface that matches the arc surface of the boiler drum.

5. The hanging boiler drum hoisting method according to claim 4, characterized in that: The saddle stop plate includes two stop plates respectively disposed at both ends of the rear edge of the saddle top plate. Each stop plate has an arc-shaped surface, and the arcs of the two stop plates are arranged opposite each other.

6. The hanging boiler drum hoisting method according to claim 1, 2, 3 or 5, characterized in that: In step three, the installation orientation of the boiler drum is determined based on the orientation of the boiler drum pipe opening, and leveling is achieved using the method of connecting horizontal pipes.

7. The hanging boiler drum hoisting method according to claim 6, characterized in that: In step four, when the boiler drum is hoisted onto the boiler drum saddle, the clamp is positioned in the contact area between the boiler drum and the boiler drum saddle.

8. The hanging boiler drum hoisting method according to claim 7, characterized in that: In step six, the installation elevation and center line of the boiler drum are determined before the drum is put into place.

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