Roller for rotating floating ladder of external floating roof tank

Abstract

The utility model relates to a roller for a rotary floating ladder of an external floating roof tank, which comprises a roller body and anti-explosion wrapping layers, the outer side of the roller body is circumferentially surrounded by a plurality of sections of the anti-explosion wrapping layers, and the anti-explosion wrapping layers are fixed on the outer circumference of the roller body through fasteners I; a fixing lug is arranged at the end of each section of anti-explosion wrapping layer and fixed to the end face of the roller body through a second fastener. The multi-section type anti-explosion wrapping layer can effectively avoid the situation that the anti-explosion wrapping layer is broken due to the fact that the whole anti-explosion wrapping layer bears the weight of the rotating floating ladder and is high in material brittleness, local deformation pressure is relieved, and the fault propagation risk is reduced.

Description

Technical Field

[0001] This utility model relates to the field of roller structure technology, specifically to a roller used for rotating floating ladders of external floating roof tanks. Background Technology

[0002] In existing technologies, crude oil storage tanks all adopt a metal external floating roof structure. The rotating floating ladder is installed between the tank top and the floating roof, serving as the only passage from the tank top to the floating roof and is also one of the important accessories of the storage tank. The upper end of the rotating floating ladder is hinged to the tank top, and the lower end is located on the floating roof track via a floating ladder rolling assembly. During the raising and lowering of the floating roof, the floating ladder makes reciprocating linear motion on the track through the rolling assembly at its bottom to adapt to the raising and lowering of the floating roof.

[0003] Since the space above the floating roof is an explosion-proof area, installing an explosion-proof coating on the roller surface is a common method to prevent sparks from being generated when the floating elevator rollers rub or collide with the track. Due to the heavy weight of the floating elevator, insufficient strength of the explosion-proof coating, and frequent operation, the explosion-proof coating on the roller surface wears and ages due to friction. After the floating roof has been in operation for a period of time, the countersunk screws used for fixing may loosen or the welds may break, causing the copper foil of the explosion-proof coating on the roller surface to crack or fall off. Furthermore, the friction and collisions caused by the rotation of the floating elevator and the misalignment with the track also accelerate the wear and aging of the explosion-proof coating.

[0004] As a vulnerable accessory of floating roof tanks, the daily inspection, maintenance, and replacement of floating roof rollers significantly increase labor and time costs, and to some extent, also increase safety risks for workers. Therefore, improving the durability and stability of the explosion-proof coating on floating roof rollers under current technological conditions is a problem that must be addressed in the operation of floating roof tanks. Utility Model Content

[0005] This invention addresses existing technical problems by providing a roller for rotating the floating ladder of an external floating roof tank.

[0006] The technical solution of this utility model to solve the above-mentioned technical problems is as follows: A roller for rotating the floating ladder of an external floating roof tank includes a roller body and an explosion-proof wrapping layer. The outer circumference of the roller body is surrounded by multiple segments of the explosion-proof wrapping layer. The explosion-proof wrapping layer is fixed on the outer circumference of the roller body by fastener one. Each segment of the explosion-proof wrapping layer is provided with a fixing ear at its end. The fixing ear is fixed on the end face of the roller body by fastener two.

[0007] Based on the above technical solution, the present invention can be further improved as follows:

[0008] Preferably, the explosion-proof wrapping layer is made of brass.

[0009] Preferably, each end of the explosion-proof wrapping layer is provided with two fixing ears, and the two fixing ears are disposed on both sides of the roller body.

[0010] Preferably, the junction between the fixing ear and the explosion-proof wrapping layer is provided with a rounded corner.

[0011] Preferably, a gap is provided between adjacent explosion-proof wrapping layers, and the gap is greater than or equal to 1.5 mm.

[0012] Preferably, a welding plate and a welding layer are provided between the fixing ear and the roller body.

[0013] Preferably, the maximum number of explosion-proof wrapping layers is 10 to 12 segments.

[0014] Preferably, the distance between the edge of the explosion-proof wrapping layer and the fastener is less than or equal to 54 mm.

[0015] Preferably, the thickness of the explosion-proof wrapping layer is 3mm-7mm and the width is 30mm-38mm.

[0016] The beneficial effects of this utility model are:

[0017] (1) The explosion-proof wrapping layer on the outside of the roller increases the mechanical strength of the roller and can effectively prevent sparks from being generated when the floating ladder roller rubs or collides with the track.

[0018] (2) The multi-segment explosion-proof wrapping layer can effectively prevent the explosion-proof wrapping layer from breaking due to the weight of the rotating floating ladder and the high brittleness of the material, thus alleviating local deformation pressure and reducing the risk of fault propagation.

[0019] (3) The explosion-proof wrapping layer is fixed to the roller by fastener one, fixing ear and fastener two, which can effectively prevent the explosion-proof wrapping layer from falling off and increase the convenience of maintenance of the explosion-proof wrapping layer.

[0020] (4) By theoretically calculating the number of segments, gap size and edge distance of the explosion-proof wrapping layer, the installation firmness of the explosion-proof wrapping layer is further improved and the service life of the roller is increased. Attached Figure Description

[0021] Figure 1 This is a three-dimensional schematic diagram of the roller of this utility model;

[0022] Figure 2 This is a schematic diagram of the roller of this utility model from another angle;

[0023] Figure 3 This is a front view of the roller of this utility model;

[0024] Figure 4 This is a side view of the roller of this utility model.

[0025] The attached diagram is labeled as follows: 1. Roller body; 2. Fastener one; 3. Mounting hole; 4. Explosion-proof wrapping layer; 4.1. Fixing ear; 4.2. Rounded corner; 5. Welding piece; 6. Welding layer; 7. Fastener two; 8. Washer; 9. Nut. Detailed Implementation

[0026] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model.

[0027] like Figures 1 to 4 As shown, this utility model discloses a roller for a rotating floating ladder of an external floating roof tank, including a roller body 1 and an explosion-proof wrapping layer 4. The roller body 1 has a mounting hole 3 at its center for a support shaft to pass through. Multiple segments of the explosion-proof wrapping layer 4 are circumferentially surrounding the outer side of the roller body 1. The explosion-proof wrapping layer 4 is fixed to the outer circumference of the roller body 1 by fastener 1 2, which is a countersunk screw. The fastener 1 2 is evenly installed on the outer circumference of the roller body 1, and the central angle between two adjacent fasteners 1 2 is 15°-30°. Each segment of the explosion-proof wrapping layer 4 has a fixing lug 4.1 at its end. The fixing lug 4.1 is fixed to the end face of the roller body 1 by fastener 2 7. A nut 9 is installed at the end of fastener 2 7 that passes through the roller body 1. Fastener 2 7 is a bolt. Washers 8 are installed between fastener 2 7 and the roller body 1, and between nut 9 and the roller body 1, to prevent loosening and increase stability. ， Ensure the secure installation of the mounting ears 4.1.

[0028] In this embodiment, the roller body 1 is made of gray cast iron Q235 material, and the explosion-proof coating layer 4 is made of brass. Specifically, the fastener 2 and the explosion-proof coating layer 4 are made of brass H62 material. By adopting a multi-segment design for the explosion-proof coating layer 4, the problem of breakage and detachment caused by stress concentration in the explosion-proof coating layer 4 is solved. The fasteners cooperate with the fixing ears 4.1 to effectively prevent the edges of the segmented explosion-proof coating layer 4 from warping and to effectively prevent it from falling off, thereby preventing sparks from being generated when the floating ladder roller rubs or collides with the track, and ensuring the safe operation of the roller.

[0029] The system's stiffness and mass vary with the number of segments in the explosion-proof wrapping layer 4. Based on existing vibration frequency and material stiffness calculation formulas, the maximum acceptable system vibration frequency for the roller body 1 is obtained, thus determining the maximum number of explosion-proof wrapping layers 4. The specific calculation method is shown in formula (1.1):

[0030]

[0031] In formula (1.1), f is the frequency of the vibration system, n is the number of segments in the explosion-proof cladding, E is the elastic modulus of the copper explosion-proof cladding, A is the cross-sectional area of ​​the explosion-proof cladding, L is the length of the explosion-proof cladding, and m is the length of the explosion-proof cladding. r Let ρ be the mass of the roller body. Cu ρ is the density of copper, b is the width of the explosion-proof coating, and h is the thickness of the explosion-proof coating.

[0032] Furthermore, to ensure stable operation, the vibration frequency f should be less than the critical frequency fn. For the case of rotation about an axis, the formula for calculating the critical frequency (natural frequency) in the prior art is as follows:

[0033]

[0034] In formula (1.2), k θ Let r be the rotational stiffness, r be the radius of the vibration system, and m be the mass of the vibration system. According to formulas (1.1) and (1.2), the maximum number of explosion-proof wrapping layers 4 that meet the conditions for stable operation is 10 to 12.

[0035] Based on the above vibration theory calculations, the number of segments of the arc-shaped explosion-proof wrapping layer 4 can be divided into two, three, four, or five segments. In addition, the arc length of each segment of the arc-shaped explosion-proof wrapping layer 4 can also be different. In this embodiment, the explosion-proof wrapping layer 4 is provided with four segments, and the thickness of each segment of the explosion-proof wrapping layer 4 is 3mm-7mm, and the width is 30mm-38mm.

[0036] Furthermore, each end of the explosion-proof wrapping layer 4 is provided with two fixing ears 4.1, which are located on both sides of the roller body 1. This improves the uniformity of force distribution on the explosion-proof wrapping layer 4, reduces the possibility of displacement of the explosion-proof wrapping layer 4, and further extends the service life of the explosion-proof wrapping layer 4.

[0037] The fixed ear 4.1 and the explosion-proof wrapping layer 4 are provided with rounded corners 4.2 to improve the smoothness of the roller body 1 when rolling, reduce jamming, and reduce the risk of cracking at the joint.

[0038] To prevent adjacent explosion-proof wrapping layers 4 from deforming or warping due to compression, and to increase the safety of the roller operation, a gap exists between adjacent explosion-proof wrapping layers 4. This gap allows for elastic deformation of the explosion-proof wrapping layers 4 due to changes in the weight and temperature of the floating ladder. The size of the gap is calculated using the following formula (1.3):

[0039]

[0040] In formula (1.3), l represents the gap between two adjacent arc-shaped copper cladding layers, γ represents the Poisson's ratio of the copper cladding material, M represents the weight of the rotating floating ladder, L represents the edge length of the arc-shaped copper cladding layer, b represents the width of the copper cladding layer, and E represents the elastic modulus of the copper cladding material. Considering the elastic deformation theory under a safety factor, the gap between two adjacent arc-shaped copper explosion-proof cladding layers 4 should be greater than 1.5 mm. In this embodiment, the explosion-proof cladding layer 4 has four segments, and the gap between adjacent explosion-proof cladding layers 4 is 2 mm to 4 mm.

[0041] A welding piece 5 and a welding layer 6 are provided between the fixing ear 4.1 and the roller body 1. The welding piece 5 is made of brass H62 material and has a thickness of 3mm-5mm. The welding layer 6 is located at the connection between the welding piece 5 and the fixing ear 4.1. The fixing ear 4.1 is fixed to the end face of the roller body 1 by the welding piece 5 and the welding layer 6, which further improves the firmness of the explosion-proof wrapping layer 4 installation, and the volume of the explosion-proof wrapping layer 4 does not increase significantly, making it easy to replace and maintain.

[0042] The distance between the edge of the copper explosion-proof wrapping layer 4 and the fastener 2 is determined by the bending deformation theory. The specific calculation method is shown in formulas (1.4), (1.5), and (1.6):

[0043]

[0044] In formula (1.4), θ is the central angle of the copper explosion-proof wrapping considering the deformation area, θ' is the central angle of the copper explosion-proof wrapping after deformation, σ is the normal stress on the deformation area of ​​the copper explosion-proof wrapping, ρ is the radius of the outer circumference of the floating ladder roller, mm; and h is the thickness of the copper explosion-proof wrapping, mm.

[0045]

[0046] In formula (1.5), ρ' is the radius of the deformed region of the copper cladding layer after deformation.

[0047]

[0048] In formula (1.6), H is the edge curling height of the copper explosion-proof coating, in mm; H s The safe height for edge curling of the copper explosion-proof coating, in mm.

[0049] By considering the bending deformation theory under the safety factor, the distance between the edge of the explosion-proof wrapping layer 4 and the fastener 2 is calculated to be less than or equal to 54mm using the above formula. In this embodiment, the distance between the explosion-proof wrapping layer 4 and the fastener 2 is 10mm-40mm.

[0050] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A roller for rotating the floating ladder of an external floating roof tank, characterized in that, The roller body (1) includes a roller body (1) and an explosion-proof wrapping layer (4). The outer circumference of the roller body (1) is surrounded by multiple segments of the explosion-proof wrapping layer (4). The explosion-proof wrapping layer (4) is fixed on the outer circumference of the roller body (1) by fastener one (2). Each segment of the explosion-proof wrapping layer (4) is provided with a fixing ear (4.1) at its end. The fixing ear (4.1) is fixed on the end face of the roller body (1) by fastener two (7).

2. The rollers for rotating floating ladders of external floating roof tanks according to claim 1, characterized in that, The explosion-proof wrapping layer (4) is made of brass.

3. The rollers for rotating floating ladders of external floating roof tanks according to claim 1 or 2, characterized in that, Each end of the explosion-proof wrapping layer (4) is provided with two fixing ears (4.1), and the two fixing ears (4.1) are located on both sides of the roller body (1).

4. The rollers for rotating floating ladders of external floating roof tanks according to claim 1 or 2, characterized in that, The fixed ear (4.1) and the explosion-proof wrapping layer (4) are provided with rounded corners (4.2).

5. The rollers for rotating floating ladders of external floating roof tanks according to claim 2, characterized in that, A gap is provided between adjacent explosion-proof wrapping layers (4), and the gap is greater than or equal to 1.5 mm.

6. The roller for the rotating floating ladder of an external floating roof tank according to claim 1, characterized in that, A welding piece (5) and a welding layer (6) are provided between the fixing ear (4.1) and the roller body (1).

7. The rollers for rotating floating ladders of external floating roof tanks according to claim 2, characterized in that, The maximum number of the explosion-proof wrapping layer (4) is 10 to 12 segments.

8. The rollers for rotating floating ladders of external floating roof tanks according to claim 2, characterized in that, The distance between the edge of the explosion-proof wrapping layer (4) and the fastener (2) is less than or equal to 54 mm.

9. The rollers for rotating floating ladders of external floating roof tanks according to claim 2, characterized in that, The explosion-proof wrapping layer (4) has a thickness of 3mm-7mm and a width of 30mm-38mm.

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