Float-type liquidometer with buoy for high-temperature high-pressure medium or high-pressure low-density medium

Abstract

The invention relates to a float-type liquidometer with buoy for high-temperature high-pressure medium or high-pressure low-density medium, comprising a float chamber, a float, a buoy chamber and a buoy. Upward lifting power is provided for the float by buoyancy to the buoy via magnetic force attraction between the float and the buoy. A force balance mechanism for lifting the float has simple structure, saves complex mechanical transmission mechanisms and has convenient transportation and installation; friction among other designed magnetic coupling components is in rolling friction structure, thus reducing lag and improving precision. The invention solves the problem of liquid level measurement in high-temperature high-pressure medium or high-pressure low-density medium and has high measurement precision, simple structure, convenient use, low maintenance and production cost and wide applicable range.

Description

technical field [0001] The invention relates to the field of liquid level measurement, in particular to a float type or magnetic float type liquid level gauge for high-temperature, high-pressure or high-pressure, low-density media. Background technique [0002] The liquid level gauge is an instrument with a wide range of applications. The existing liquid level measuring instruments are of various types. Now for high temperature and high pressure vessels, where the medium is highly corrosive or the pressure is high and the medium density is low, the following analysis is made: [0003] In the case of high pressure or high pressure and low density, it is very difficult to manufacture the float due to high pressure or high pressure and low medium density. For high temperature and high pressure, the manufacture of the float is even more difficult: because the metal material is in When the strength decreases at high temperature, the wall thickness of the float needs to be increa...

AI Technical Summary

Problems solved by technology

But it has the following disadvantages: 1. The float lacks upward external lifting force, and the vernier does not provide this force, so it is still difficult to make a float that can withstand higher pressure or low specific gravity and high sensitivity

2. Both the float and the vernier are sliding friction, resulting in a large friction coefficient, which makes the friction force large and affects the accuracy and sensitivity

Its shortcomings are: 1. The buoy is one of the loads of the float, which is not conducive to making a high-pressure low-specific gravity float

2. The float lacks the upward lifting force from the outside world, so it is still difficult to make a float that can withstand higher pressure or low specific gravity and high sensitivity

[0009] As described in ZL97213710.6, it adopts a magnetic coupling structure, and adds a counterweight to the ribbon outside the float to balance the weight of the float, which is conducive to improving its operating temperature and pressure range, and making it suitable for use in low-density applications , but its shortcomings are: 1. When the working pressure is high, the partition between the magnetic coupling parts will be very thick, and the axial end face of the partition is flat, which is equivalent to the flange or blind plate on the pipeline , its thickness is determined by the working pressure, temperature, diameter, and the selected material, and the standard design will be very thick. If the thickness of the partition is too large, the magnetic coupling force will be too small until it does not work. The attenuation of the magnetic attraction force and the distance It is at the geometric level. If it is coupled radially outside the circular pipe, its wall thickness will be much smaller. The wall thickness will be calculated by the design of pressure vessels or pipes. It can also be calculated by checking the pressure vessel or pipe design manual.

2. There are many parts in the floater, and corrosion-resistant materials must be used for corrosive media, which increases the manufacturing cost

3. Steel wire and steel belt are used inside, medium fluctuations can easily cause breakage and affect service life

4. The upper and lower pulleys tighten the ribbon, which increases the friction and affects the sensitivity and measurement accuracy

5. The magnetic coupling is a sliding friction, the friction is large, and it also affects the accuracy

But their shortcomings are: 1. At high temperature and high pressure, the float chamber and the counterweight chamber must be made of expensive high alloy steel, which are two chambers, thus greatly increasing the production cost

2. The counterweight chamber will accumulate condensate, and when the counterweight is immersed in the condensate, the measurement accuracy will be affected by the upward buoyancy

4. In high temperature occasions, high temperature bearings must be used

5. There are many internal parts, which affect the reliability of use, especially in high temperature occasions

6. There are many internal parts and they are in the pressurized float chamber, so the maintenance is troublesome and the maintenance cost is high

7. The magnetic steel is in the float chamber, and the demagnetization temperature of the magnetic steel limits the service temperature of the liquid level gauge

But its disadvantages are: 1. The float and the counterweight are in the same float chamber. Under the same sensitivity or precision, the diameter of the float chamber must be increased.

Therefore, a lot of high-alloy steel is wasted in high and low temperature situations, which increases the production cost

2 The length of the float chamber is doubled, which further increases the manufacturing cost, and also causes bulky, space-consuming, and inconvenient transportation

3. There are many internal parts, and the corrosive medium consumes a lot of expensive metal materials

4. If the accuracy or sensitivity is guaranteed, the diameter of the float needs to be large. The increase in the wall thickness of the float chamber caused by the large diameter of the float will cause the effect on the reed switch to be too weak until it does not work.

5. Easy to damage during transportation

6. Manufacturing and assembly are more difficult

7. There are many internal parts and they are in the pressurized float chamber, so maintenance is troublesome, and seals are often required to be replaced during maintenance, resulting in high maintenance costs

[0012] As described in the application number 93115704.8 invention patent application, its advantage is that it adopts a counterweight mechanism to balance the weight of the float, but it also has the following disadvantages: 1. The internal pressure resistance of the tube is much greater than the external pressure, because the tube bears the external pressure

Large wall thickness at high pressure, waste of material

2. Two pipes extend into the container, which wastes more materials, especially at high temperature

Many standards stipulate that when the operating temperature is greater than 400 ° C, carbon steel is not allowed for pressure-bearing components or force-bearing components (this article applies to all the foregoing and the following), and high-alloy steel is required for the pipeline where the counterweight is located at this time, resulting in Higher cost. 3. When used in corrosive media, more corrosion-resistant materials are required, which further increases the cost

4. Complex structure

5. Sliding friction between magnetic coupling parts leads to large friction force, which affects accuracy

[0014] 1. Higher working pressure or high pressure and low density occasions are difficult to apply;

[0015] 2. The use of precious metals or corrosion-resistant materials is large, (pulleys, bearings, float chambers, etc. need to be selected according to process conditions, such as high temperature and corrosion), which increases the manufacturing cost;

[0016] 3. The counterweight or the counterweight is immersed in the liquid to be measured, which will affect the measurement accuracy;

[0017] 4. Difficulty in assembly and calibration;

[0018] 5. Due to its huge structure, reassembly and adjustment after transportation will increase the burden of packaging and transportation;

[0019] 6. There are many friction pairs or there is sliding friction between the float and the pipe wall, resulting in high friction (steel-to-steel sliding friction coefficient μ is 0.15, steel-to-steel cylindrical radial rolling friction coefficient is 0.05, spherical steel balls to steel The coefficient of friction is less than 0.003

[0022] 7. There are many internal parts in the float, and maintenance is troublesome. If there are many internal parts, the failure rate will be high, and the number of repairs will be high. During maintenance, the seal is often replaced, and water pressure and air tightness tests are required, resulting in high maintenance costs.

[0023] 8. Some floats lack the upward lifting force from the outside world

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