CN204250668U - A kind of hermetically-sealed construction without oil-gas space of floating roof tank floating plate - Google Patents

Abstract

The utility model relates to a sealing structure for an oil-gas-free space of a floating plate of a floating roof storage tank, which is composed of a primary sealing device and a secondary sealing device, and the primary sealing device includes a primary sealing pressure plate A, a primary sealing pressure plate B and a primary sealing tape , the secondary sealing device includes a second anti-evaporation diaphragm, the beginning of the second anti-evaporation diaphragm is pressed and fixed by the primary sealing pressure plate B, then extends to the tank wall and is wound up along the tank wall to the upper end of the elastic pressure plate and Compressed and fixed by it, the second evaporative diaphragm and the first anti-evaporative diaphragm form a secondary sealed upper annular cavity on the periphery of the floating roof after being wound, and the filling in the cavity occupies the space between the primary and secondary seal Bit of low-density sponge padding. The secondary seal formed by the utility model on the tank body not only improves the overall sealing performance of the oil storage tank, but also reduces the accumulation of oil and gas between the primary and secondary seals, increases the safety factor, eliminates fire hazards, and has low cost. It has the significance of large-scale promotion.

Description

A sealing structure for the oil-gas-free space of the floating plate of the floating roof storage tank

technical field

     The utility model relates to a floating roof sealing structure for a large oil storage tank, in particular to a sealing structure for the oil-gas-free space of the floating plate of the floating roof storage tank.

Background technique

There is an annular gap of about 200-250mm between the outer edge of the floating plate of the floating roof tank and the tank wall. This gap is a necessary space for the floating plate to run up and down, and it is also the main channel for it to distribute oil and gas. Usually, a sealing device is used to close it. Seal to reduce the evaporation loss of oil and gas. Appendix C of American API650 and Japanese JISB8501 both require the use of primary and secondary sealing devices. my country's GB50737 "Code for Design of Petroleum Storage Depot" 7.5.7.1 "Sealing device should be composed of primary sealing and secondary sealing". "PetroChina Light Oil Storage Tank Technical Guidelines (Trial)" Article 3.7.11 "Floating roof oil tanks should be provided with primary seal and secondary seal regulations". At present, in the actual production management and operation of large storage tanks in my country, primary and secondary sealing devices are basically installed, and its structure is shown in Figure 1. Affected by construction quality and manufacturing errors, oil storage tanks have irregular tank walls. During the lifting process of the floating roof, the primary seal is not tight, resulting in the space under the primary seal communicating with the space between the primary and secondary seals, and oil and gas Upward to between the primary and secondary seals; or during the up and down operation of the floating roof of the storage tank, the oil product condenses and hangs in the relatively fixed space of the primary and secondary seals, so that a mutual relationship is formed between the primary and secondary seals or with the lower part of the primary seal. In the connected explosion hazard area, due to the existence of explosive oil and gas space, if ignition occurs at this position during the lightning current discharge process, it is very likely to cause an explosion and cause a fire on the sealing ring. Several storage tank fires that have occurred in recent years The results of the accident analysis show that the storage tanks where the fire accident occurred all adopted the secondary sealing structure with oil and gas space. Therefore, how to eliminate the oil-gas space between the primary and secondary seals has been a subject of discussion and development by experts at home and abroad. Sinopec 2011 [754] 4.1.4 "The oil-gas space between the primary seal and the secondary seal should be reduced as much as possible." Some domestic oil product storage and transportation companies use forced ventilation or nitrogen filling to reduce the accumulation of oil and gas between the primary and secondary seals. However, there are also defects such as large safety risk factor or high cost.

Chinese patent CN101168401A discloses a composite sealing device and its application in the sealing of floating roof storage tanks. The device has a wear-resistant rubber belt, and the middle part of the side is provided with a rubber diaphragm, which is divided into upper and lower parts. The upper part of the space is provided with an elastic rubber bag filled with light filler material, and the lower part is provided with a liquid-filled bag. The liquid-filled bladder eliminates the oil-gas space between the wear-resistant rubber strap and the oil surface of the floating roof storage tank, and the elastic rubber bladder eliminates the oil-gas space between the primary and secondary seals. The rubber sheet with a circular bolt hole is fixed on the connecting component of the rubber scraper of the secondary sealing device through bolts.

According to the technical features of this patent, when the floating plate is actually in operation, the rubber bladder is tightly wrapped by the rubber wear-resistant belt between the annular gap between the edge plate of the floating plate and the tank wall, and the rubber bladder is filled with a certain amount of liquid (the specific gravity of non-oil liquid) The oil in the Yuanda storage tank has a specific gravity of 8.6). Due to its large diameter and heavy self-weight, it exerts a certain pressure on the tank wall. When the floating plate rises, this pressure is the distance between the rubber wear-resistant belt and the tank wall. The friction force between them, the direction is downward, will cause the rubber wear-resistant belt to pull vertically downward. The wear-resistant rubber belt and the rubber scraper are directly connected together, and the pressure plate exerts a certain pressure on the rubber scraper to make it tight. It is attached to the tank wall and rises together with the floating plate. If the downward pulling force generated by the rubber belt and the resistance of the rubber scraper during the rising process exceed the bearing capacity of the pressure plate, the pressure plate will be folded downwards. Cause the failure of the secondary seal; if it is serious, it will cause the entire floating roof to sink. In addition, since the elastic rubber bladder and the liquid-filled bladder are used as the inner tank of the rubber wear-resistant strap, not only the weight but also the equipment cost are increased.

Contents of the invention

In view of the problems existing in the above-mentioned prior art, the purpose of this utility model is to provide a sealing structure for the oil-gas-free space of the floating plate of the floating roof storage tank, which can run up and down in a sealed state while maintaining the buoyancy of the floating plate of the storage tank Under the premise of eliminating the accumulation of oil and gas, the fire hazard of the oil storage tank is fundamentally eliminated.

The technical solution adopted by the utility model to achieve its purpose: a sealing structure of the oil-gas-free space of the floating plate of the floating roof storage tank, which is composed of a primary sealing device and a secondary sealing device, and the primary sealing device includes a primary sealing pressure plate A , primary sealing pressure plate B and primary sealing tape, the primary sealing pressure plate A and primary sealing pressure plate B are fixed on the sealing fixed plate on the outer periphery of the floating roof; the primary sealing tape is compressed and fixed by primary sealing pressure plate A and primary sealing pressure plate B , and form a lower annular cavity around the floating roof, the cavity is filled with primary sealing filler to form a primary seal to the tank body; the secondary sealing device includes an elastic pressure bearing plate, a first anti-evaporation diaphragm and a And the rubber bracket attached to the inner wall of the storage tank and can move up and down with the floating roof, the elastic pressure bearing plate and the first anti-evaporation diaphragm are arranged between the rubber bracket and the sealing fixing plate, the The first anti-evaporation diaphragm is located under the elastic pressure bearing plate; the secondary sealing device also includes a second anti-evaporation diaphragm, the beginning of the second anti-evaporation diaphragm is compressed and fixed by the primary sealing plate B and extends toward the tank wall and along the The tank wall is wound up to the top of the elastic pressure bearing plate and fixed by it. After the second evaporation diaphragm is wound, it forms a secondary sealed upper annular cavity with the first anti-evaporation diaphragm on the periphery of the floating roof. The upper annular cavity is filled with a secondary sealing filler that occupies the oil-gas space between the primary and secondary seals.

Further, the primary and secondary sealing packings are low-density sponge lightweight packings, the models of which are JM-15 or JM-20.

Further, the ends of the primary sealing platen A and the primary sealing platen B have an upturned structure and wrap the glue layer.

It can be seen from the above technical scheme that after the second anti-evaporation diaphragm is wound, the upper annular cavity formed on the periphery of the floating roof together with the first evaporation diaphragm is directly filled with low-density sponge filler to form a secondary seal for the tank body and realize a 1. Occupying the oil and gas space between the secondary seals, thereby reducing the accumulation of oil and gas between the primary and secondary seals; the utility model saves the inner tank but also achieves the overall sealing performance of the oil storage tank, and can keep the storage tank floating The plate moves up and down normally with the oil level, increases the safety factor, eliminates the purpose of fire hazard, and has low cost, which has the significance of large-scale promotion.

Description of drawings

The utility model will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is the schematic cross-sectional structure diagram of the primary and secondary sealing devices of the floating roof of the large oil storage tank in the present technology;

Fig. 2 is a schematic sectional view of the structure of the utility model;

FIG. 3 is a schematic diagram of an enlarged structure of B in FIG. 2 .

In the figure: 1. Rubber bracket, 2. Elastic bearing plate, 3. Evaporating diaphragm, 31. First evaporating diaphragm, 32. Second evaporating diaphragm, 4. Oil and gas space, 5. Primary sealing tape, 6. Floating roof , 7, primary sealing packing, 8, primary sealing plate A, 9, primary sealing plate B, 10, tank wall, 11, secondary sealing packing, 12, sealing fixed plate.

Detailed ways

As shown in Figure 2, the utility model consists of a primary sealing device and a secondary sealing device.

The primary sealing device comprises primary sealing platen A 8, primary sealing platen B 9 and primary sealing tape 5. The primary sealing platen A 8 and the primary sealing platen B 9 are fixed on the sealing plate of the outer periphery of the floating roof 6 by bolts; Turn and extend to the tank wall 10, then upward along the tank wall, the tail end is wound to the bottom of the primary sealing platen B9 and pressed and fixed by it, after the primary sealing tape is wound, a lower annular cavity is formed around the floating roof, and the cavity is filled The primary sealing packing 7 makes the primary sealing of the tank body formed between the outer periphery of the floating roof 6 and the tank wall.

The secondary sealing device includes a rubber bracket 1 , an elastic pressure bearing plate 2 and a first anti-evaporation diaphragm 31 . The rubber bracket 1 is located above the sealing fixing plate 12 and attached to the inner wall of the storage tank and can move up and down with the floating roof 6 . The upper end of the elastic pressure bearing plate 2 is fixed on the lower end of the rubber bracket 1 by bolts, and the lower end of the elastic pressure bearing plate 2 is fixed on the sealing fixed plate on the periphery of the floating roof 6 by bolts. The first anti-evaporation membrane 31 is located under the elastic pressure bearing plate 2 and is fixed by pressing it. The secondary sealing device is also provided with a second anti-evaporation diaphragm 32, the starting end of the second anti-evaporation diaphragm 32 is compressed and fixed by the primary sealing platen B9 and extends toward the tank wall 10, and then is wound upwards along the tank wall until it is elastically pressure-bearing The upper end of the plate 2 is pressed and fixed by it. After the second evaporation diaphragm 32 is wound, it forms an upper annular cavity with the first anti-evaporation diaphragm on the periphery of the floating roof to form a secondary seal to the tank body. The secondary sealing filler 11 is filled, and the second anti-evaporation diaphragm 32 contacts the tank wall to form a secondary seal to the tank body. The upper annular cavity is filled with low-density sponge packing to occupy the oil-gas space between the primary and secondary seals. The primary and secondary sealing packings are all made of low-density sponge lightweight packing, the model is JM-15 or JM-20. The end edges and sharp corners of the primary sealing platen A 8 and the secondary sealing platen B 9 are polished and smooth, adopt an upturned structure and are wrapped with a rubber layer, and the thickness of the rubber layer is 2-3mm.

According to the design requirements, under the standard clearance condition, the pressure of the primary sealing device on the tank wall is 12Kg (compression force on the unit circumference), and the rubber sealing belt is designed and produced according to HG/2809 "Rubber Sealing Belt for Soft Sealing Devices for Floating Roof Oil Tanks".

The above is only an embodiment of the utility model, and for those skilled in the art, the utility model has many modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the inventive idea and principle of the present utility model shall be included in the protection scope of the present utility model.

Claims (3)

1. the hermetically-sealed construction without oil-gas space of a floating roof tank floating plate, be made up of once sealing device and secondary sealer, described once sealing device comprises once sealing pressing plate A, once sealing pressing plate B and once sealing adhesive tape, and described once sealing pressing plate A and once sealing pressing plate B is fixed on the sealing adapter plate of floating roof periphery; Described once sealing adhesive tape is fixed through once sealing pressing plate A and once sealing pressing plate B, and forms lower toroidal cavity at floating roof periphery, and in chamber, filling once sealing filler, forms the once sealing to tank body; Described secondary sealer comprises elastic bearing plate, the first vaporization prevention barrier film and to be positioned at above sealing adapter plate and to be fitted in reservoir walls and the rubber rubbing board that can move up and down with floating roof, described elastic bearing plate and the first vaporization prevention barrier film are located between described rubber rubbing board and described sealing adapter plate, and described first vaporization prevention barrier film is positioned at below elastic bearing plate; it is characterized in that:described secondary sealer also comprises the second vaporization prevention barrier film, the top of described second vaporization prevention barrier film is fixed backward tank skin by once sealing pressing plate B and extends and scroll up around to elastic bearing plate upper end along tank skin and be fixed by it, form the upper toroidal cavity of secondary seal after described second evaporation membrane winding at floating roof upper periphery with the first vaporization prevention barrier film, in described upper toroidal cavity, filling is to the secondary seal filler of oil-gas space occupy-place between first and second sealing.

2. the hermetically-sealed construction without oil-gas space of floating roof tank floating plate according to claim 1, is characterized in that: described first and second gland packing adopts low-density sponge light filler, and model is JM-15 or JM-20.

3. the hermetically-sealed construction without oil-gas space of floating roof tank floating plate according to claim 1, is characterized in that: the end of described once sealing pressing plate A and once sealing pressing plate B is for upwarping structure and wrapping up glue-line.