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58,About the price of cryogenic storage tank - Introduction to storage tank - Doer equipment

Classification:Forum PublishTime:2019-08-29 14:20:46

About the price of cryogenicstorage tank - Introduction to storage tank - Doer equipment


What are the structural characteristics of cryogenic storage tanks? cryogenic storage tanks are divided into inner tanks and outer tanks, and each has its own characteristics and special design in the design of inner and outer tanks. Secondly, in order to better achieve the thermal insulation conditions of low-temperature storage tanks, the special thermal insulation materials of interlayer are also the importance of selection. The following contents are divided into:


1.1 structural features


The storage tank is of double cylinder structure, the inner cylinder is made of s30408 stainless steel, the outer cylinder is made of Q345R high-quality carbon steel, and a special support structure is adopted between the inner and outer cylinders. The annular thermal insulation interlayer between the inner and outer cylinders is 250mm thick (the cold insulation thickness of the inner and outer heads is not less than 400mm), filled with perlite thermal insulation materials and vacuumized to ensure good thermal insulation performance of the equipment. The storage tank is supported by epoxy glass cloth rod, which is firm and reliable, and fully ensures the convenience and safety of the use process. The outer tank surface has been thoroughly derusted by sand blasting to ensure that the paint will not deteriorate for at least two years.


1.2 inner tank


As the main container for low-temperature medium, the inner tank is the core component of the equipment. Its main material meets the requirements of gb24511 austenitic stainless steel 06cr19ni10 (s30408) steel plate, with additional rp1.0 requirements. The allowable stress of the material is 166.7mpa. Our products are designed and manufactured according to the national standard GB150 without strain strengthening technology, so the thickness of the steel plate is thicker and safer.


1.3 outer tank


As the protective shell of the thermal insulation system, the outer tank adopts low alloy steel Q345R which meets gb713 and has good weldability. Its compactness will directly affect the interlayer vacuum and play a decisive role in the thermal insulation effect of the equipment.


The surface of the outer tank has been thoroughly shot peened to achieve Sa2.5 standard. High quality paint is selected to ensure that the paint will not deteriorate for at least two years.


1.4 insulation system


The theoretical calculation of evaporation rate index is higher than the standard requirements, so as to minimize heat transfer and ensure good evaporation rate index on the premise of ensuring the safety and reliability of the equipment. The equipment adopts vacuum powder insulation. The insulation material used is expanded perlite (pearlite). Its performance requirements are as follows:


Serial number

Indicator name

index

1

Bulk density

40~60kg/m3

2

granularity

0.1mm ~ 0.2mm not less than 90%

3

thermal conductivity

< 0.026w / m · K · s (normal pressure, temperature 310 ~ 77K)

4

Moisture content

< 0.1% (mass ratio)

5

Unexpanded rate

1%

6

PH

6.57.5

In order to effectively improve the thermal insulation performance, a light inhibitor with good chemical stability and no explosion in oxygen enriched environment is added to pearlescent sand. In order to avoid the pearlescent sand from moisture (high moisture content), special tooling is made for the storage, transportation and loading of pearlescent sand.


During the filling of pearlescent sand, the filling density shall be strictly controlled to prevent settlement as much as possible (≥ 1.8 times the interlayer volume).


The liquid pipeline from the inner tank is provided with a liquid seal (gas seal liquid) structure to avoid the continuous gasification of low-temperature liquid in the pipeline.


The inner tank support material adopts epoxy glass cloth rod with small thermal conductivity, strong pressure bearing capacity, low air release rate and strong low-temperature impact resistance.


When the tank needs to use the metal sling of the same material as the inner tank, ensure a long enough thermal bridge to minimize external heat conduction.


1.5 vacuum system


The vacuum degree of interlayer directly affects the thermal insulation performance of equipment. The thermal conductivity of pearlite in vacuum environment is only 1 / 10 of that in atmospheric environment. Before the inner tank is sleeved with the shell, helium mass spectrometry leak detection shall be carried out for the inner tank, pipeline and outer tank. It can be sleeved only after it is qualified.


The vacuum filtering device adopts the skeleton structure with the largest diffusion surface, and the vacuum filtering pipeline as long as possible is buried in the interlayer pearlite to ensure the complete extraction of interlayer air.


A certain amount of adsorbent is placed in the vacuum interlayer to prolong the vacuum life, and the guarantee of vacuum life is effectively guaranteed from the design and process. The air leakage rate of vacuum valve and vacuum connector is less than 5 × 10-7Pa·m3/s。


With vacuum gauge, it is convenient to detect the vacuum in real time, and the vacuum gauge and vacuum isolation valve are imported products to ensure rapid, reliable and complete vacuum pumping and accurate vacuum measurement;


The vacuum valve and connector shall be protected and sealed with lead after delivery inspection.


Solemn commitment: the vacuum degree warranty of our products is three years.


1.6 pipeline system


The storage tank is equipped with relief pipeline, top spray filling pipeline, bottom filling and discharge pipeline, self pressurization pipeline, liquid level and pressure measurement pipeline, overflow pipeline and other pipelines and accessories to meet the requirements of equipment pressure relief, venting, liquid filling, liquid discharge, pressurization, overflow, pressure and liquid level display.


Filling pipeline: liquid can be filled at the bottom or at the top, which is convenient for the design and combination of various process flows. The spray device is adopted at the top, so that the inner tank can be evenly cooled during the first liquid filling to avoid excessive temperature difference stress.


Liquid discharge pipeline: set corresponding stop valves and joints to meet the requirements of liquid discharge capacity.


Safety pipeline: the pressure relief pipeline is directly connected with the gas phase space of the storage tank, the diameter of the pipeline meets the safety relief requirements, and its internal cross-sectional area is greater than the inlet cross-sectional area of the safety relief device. A combined safety device (safety valve) is installed on the pipeline to prevent overpressure operation of the equipment. In addition, it is also equipped with auxiliary explosion-proof disc device to further prevent equipment overpressure. This explosion-proof disc will completely burst when the safety valve fails and the pressure exceeds the pressure borne by the explosion-proof disc, so that the pressure of the inner tank can be released.


Self pressurization pipeline: the pressure grade of the self pressurizer matches the design pressure of the storage tank, and its vaporization capacity meets the requirements of the design liquid discharge rate and pressure rise rate.


Overflow pipeline: in order to prevent the filling rate from exceeding the rated filling rate, overflow pipeline and full measuring valve are set, which is a typical, proven and reliable anti overload device.


The low-temperature pipeline is specially designed according to the needs of the low-temperature liquid storage tank, which is centrally led out from the lower end to facilitate the layout, operation and control of the system pipeline, and a special transition structure is adopted at the outlet to meet the low-temperature requirements, reduce the stress caused by the thermal expansion and cold contraction of the pipeline and ensure the safety of the storage tank.


The liquid will be retained in the pipeline between the two valves. When the two valves are closed, the vaporization of the low-temperature liquid between the two valves will cause overpressure in the pipe section. Therefore, a safety device (safety valve) must be equipped for the pipeline.


Check strictly before installation to ensure that the internal and external surfaces have been cleaned, free of sundries, oil stains and dry. Pressure test and leak detection shall be carried out together with the inner tank after the pipeline passes the NDT.


Filling operation:


Before each filling, the storage tank shall be visually inspected to see whether there is damage, whether it is clean and whether it meets the conditions of liquid operation. If damage (such as serious depression, loose joint, etc.) is found, it shall be repaired as soon as possible;


All sold storage tanks are filled with low purity nitrogen to prevent water from entering the storage tank. Therefore, the storage tank shall be completely purged with suitable gas before filling; When filling the storage tank with cryogenic liquid, it can be transported by cryogenic pump or through pressure difference; The transportation pipeline can be shortened as far as possible. Long non insulated transportation pipeline will lead to filling loss, increase filling time and increase liquid gasification capacity.


Products supplied by Suzhou duer: vacuum storage tank, storage tank, cryogenic storage tank, cryogenic vacuum storage tank, LNG cryogenic storage tank, LNG storage tank, liquid oxygen storage tank, liquid nitrogen storage tank, 50 cubic liquid oxygen storage tank, 100 cubic liquid oxygen storage tank, 50 cubic liquid nitrogen storage tank, 100 cubic liquid nitrogen storage tank, LNG storage tank, liquid oxygen storage tank, liquid nitrogen storage tank, service hotline: 0512-81666096





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