Hobbing cutter type paraffin scraping device for storage tank

Abstract

The invention relates to a storage tank hob type paraffin scraping device, which is mainly used for solving the problem of paraffin deposition on the wall of a floating roof oil storage tank and comprises a hob head consisting of two push rods with springs, wherein rolling scrapers are mounted at the front ends of the push rods. The rolling scraper is composed of at least three blades, the outer ends of the blades are in an arc shape, when the rolling scraper is pressed on the tank wall through the push rod, at least two blades make contact with the tank wall at the same time, and the rolling scraper is installed on the push rod through a hob shaft, can freely rotate and scrapes accumulated wax on the tank wall when moving up and down along with the floating disc. Through the multi-blade design and the spring push rod structure, the paraffin scraping effect is stable, the paraffin scraping device adapts to irregular surfaces such as tank wall weld joints, and the paraffin scraping device has the advantages of being convenient to install, safe, reliable, long in service life and the like.

Description

Technical Field

[0001] The invention relates to the technical field of storage tank wax scraping, in particular to a roller type wax scraping device for a floating roof oil storage tank. Technical Background

[0002] With the rapid development of social economy, the demand for crude oil continues to grow, the construction scale of oil storage tanks continues to expand, and the performance requirements for floating roof oil storage tanks are also increasing. Crude oil is a mixture of various hydrocarbons, in a thick liquid or semi-solid state. Its main components include alkanes, and contain elements such as sulfur, oxygen, nitrogen, phosphorus, and vanadium. According to different components, crude oil can be divided into three categories: paraffin-based crude oil, cycloalkane crude oil, and intermediate-based crude oil. The density of crude oil is usually between 0.75 and 0.95, which is lower than the density of water; its freezing point ranges from -50℃ to 35℃, and crude oil with a higher paraffin content has a higher freezing point. Paraffin is a white or light yellow solid composed of higher alkanes, with a melting point between 37℃ and 76℃. When the crude oil in the storage tank is under low temperature or low pressure conditions, paraffin will precipitate and adhere to the tank wall, forming a waxing phenomenon.

[0003] Waxing of crude oil on the wall will cause the following hazards:

[0004] 1. Pollution and cargo damage: When the temperature rises, the wax on the wall will flow along the tank wall to the floating roof, causing pollution and cargo loss.

[0005] 2. Economic losses and environmental hazards: Wax evaporates at high temperatures or sublimates at low temperatures, which not only causes economic losses but also aggravates environmental pollution.

[0006] 3. Affecting the sealing of the floating plate: Waxing makes the surface of the tank wall uneven, affecting the adhesion of the floating plate seal to the wall, resulting in loose sealing and increased volatilization of oil and gas.

[0007] 4. Safety hazard: Wax flowing to the floating roof may affect the safe operation of the floating roof.

[0008] At present, the oil tank scraping device mainly adopts the following two methods:

[0009] 1. Spring-type wax scraping device: The scraper is pressed against the tank wall by the spring plate, and the wax is scraped by the elastic force of the spring. Its advantages are simple structure and good wax scraping effect, but long-term use is prone to problems such as spring fatigue failure and rubber sealing belt damage, and the positive pressure fluctuates with the change of the gap between the tank wall and the floating roof, affecting the wax scraping effect.

[0010] 2. Heavy hammer type wax scraping device: The heavy hammer provides constant positive pressure to make the scraper close to the tank wall. Its advantage is stable positive pressure, but the structure is complex, there are many rotating nodes, and mechanical failure is prone to occur during long-term operation. Summary of the invention

[0011] In order to solve the deficiencies of the prior art, the present invention provides a roller-type wax scraping device, which has the advantages of convenient installation, safety and reliability, and long service life.

[0012] The objective of the present invention is achieved through the following technical solutions: A roller-type wax scraping device, characterized in that it includes a roller frame composed of two spring-loaded push rods, and a roller is installed at the front end of the push rod. The roller consists of at least three blades, and the outer ends of the blades are in an arc shape. When the push rod presses the roller against the tank wall, at least two blades are in contact with the tank wall at the same time. The number and angle of the blades can be adjusted according to actual needs. For example, when four blades are used, the blades are at a 45° angle to the tank wall; when three blades are used, the blades are at a 30° angle to the tank wall. When the wax scraping device moves up and down with the floating plate, the blades can scrape off the accumulated wax on the tank wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 : Schematic diagram of a roller-type wax scraping device.

[0014] 1: Shrapnel; 2: Push rod; 3: Rolling scraper.

[0015] Figure 2 : Schematic diagram of the scraper of the roller type wax scraping device.

[0016] 31: blade; 32: hob shaft; 33: reinforcing rib.

[0017] Figure 3 : Schematic diagram of a rolling scraper blade. DETAILED DESCRIPTION

[0018] 1. The structure of the roller type wax scraping device (such as Figure 1 shown):

[0019] The spring (1) is a leaf spring, one end of which is fixed on the floating plate, and the other end is connected to the upper end of the push rod (2). The two push rods (2) form a rolling cutter frame, and the lower end is equipped with a rolling scraper (3).

[0020] The spring sheet (1) keeps the rolling scraper (3) in contact with the tank wall and provides appropriate pressure through the push rod (2). The rolling scraper (3) is installed on the push rod (2) through the rolling scraper shaft (32) and can rotate freely. The function of the spring sheet (1) is to use elastic force to provide the rolling scraper (3) with the pressure required for scraping wax and to supplement the gap between the scraper and the tank wall. Therefore, the same purpose can be achieved by using a spring. When using a spring, the push rod (2) needs to be installed on the tank wall using a hinge.

[0021] When the rolling scraper (3) encounters the weld of the tank wall, the blade (31) is blocked. If the resistance exceeds the rotational torque, the rolling scraper (3) will roll across the weld.

[0022] 2. Scraper structure (such as Figure 2 shown):

[0023] The rolling scraper (3) is formed by two blades (31) being butt-inserted and welded, with a rolling cutter shaft (32) welded at both ends and fixed on the push rod (2) through a split pin.

[0024] In order to improve the overall rigidity, a reinforcing rib (33) is welded on the hob shaft (32). The reinforcing rib (33) is a circular disc with holes and is used to connect the blade (31) and the hob shaft (32).

[0025] 3. Blade design (such as Figure 3 shown):

[0026] The blade (31) has arc-shaped edges on both sides, and the curvature is designed according to the number of blades and the curvature of the tank wall. Figure 3 The embodiment shown is a four-blade embodiment, in which two blades (31) are butt-welded, with a gap of the thickness of the blades left in the middle.

[0027] advantage

[0028] 1. Easy installation: simple structure, easy to install and maintain on site.

[0029] 2. Safe and reliable: The hob design can effectively avoid jamming and adapt to irregular surfaces such as tank wall welds.

[0030] 3. Long service life: The use of high-strength materials and optimized structural design significantly extends the service life of the device.

[0031] 4. Good wax scraping effect: The multi-blade design ensures stable wax scraping effect and adapts to different working conditions.

Claims

1. A tank roller type wax scraping device, characterized in that: include: Two spring-loaded push rods (2) form a hob frame; A rolling scraper (3) is mounted on the front end of the push rod (2), wherein the rolling scraper (3) is composed of at least three blades (31), and the outer ends of the blades (31) are in an arc shape; When the push rod (2) presses the rolling scraper (3) against the tank wall, at least two blades (31) are in contact with the tank wall at the same time; The rolling scraper (3) is mounted on the push rod (2) via a rolling scraper shaft (32) and can rotate freely.

2. The tank roller type wax scraping device according to claim 1, characterized in that: The number of blades (31) of the rolling scraper (3) is at least three. When there are three blades, the blades (31) form an angle of 30° with the tank wall; when there are four blades, the blades (31) form an angle of 45° with the tank wall.

3. The tank roller type wax scraping device according to claim 1, characterized in that: The push rod (2) is connected to the floating plate via a spring (1); the spring (1) is a leaf spring, one end of which is fixed to the floating plate and the other end is connected to the upper end of the push rod (2) for providing thrust to the push rod (2); the spring structure is not necessary and a spring can be used to replace the spring.

4. The tank roller type wax scraping device according to claim 1, characterized in that: The blade (31) of the rolling scraper (3) has arc-shaped edges on both sides, and the curvature is designed according to the number of blades and the curvature of the tank wall.

5. The tank roller type wax scraping device according to claim 1, characterized in that: A roller shaft (32) is welded to both ends of the rolling scraper (3), and the roller shaft (32) is fixed to the push rod (2) via a cotter pin.

6. The tank roller type wax scraping device according to claim 6, characterized in that: A reinforcing rib (33) is welded on the roller cutter shaft (32), and the reinforcing rib (33) is a circular disc with holes, and is used to connect the blade (31) and the roller cutter shaft (32) to improve the overall rigidity of the rolling scraper (3).

7. The tank roller type wax scraping device according to claim 1, characterized in that: When the rolling scraper (3) has four blades, the blades (31) are connected by butt welding, with a gap of the thickness of the blades left in the middle.

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