A vacuum degassing process

A vacuum and pre-vacuum technology, which is applied in fixed-capacity gas storage tanks, gas/liquid distribution and storage, liquid variable capacity machinery, etc., can solve the problem of difficult gas pumping resistance, large heat leakage, and time-consuming Long and other problems, to achieve the effect of good time-out treatment, good performance and low cost

Active Publication Date: 2021-03-23
CHENGDU CRAER CRYOGENIC EQUIP
View PDF7 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the outgassing of the thermal insulation material, supporting structure and the inner and outer wall materials of the storage tank, the vacuum degree of the interlayer is changed from one atmospheric pressure (1.02×10 5 Pa) drawn to 1.33×10 -2 It takes a long time for the vacuum degree above Pa to be longer
In order to speed up the pumping, the inner and outer walls of the storage tank are usually baked, so the pumping of the interlayer is a time-consuming and expensive work
The most important thing is that when the conventional evacuation process is adopted, the gas between the interlayers of the storage tank is difficult to be pumped due to the huge pumping resistance, resulting in a large amount of heat leakage caused by the residual gas in the interlayer

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] A vacuum degassing process, comprising the following steps:

[0038] Step 1, the pumped product is subjected to helium mass spectrometry leak detection;

[0039] Step 2. Install an evacuation unit, a temperature monitoring device, a vacuum connection meter, and an inner and outer frame heating device for the pumped product that has passed the leak detection; start the inner and outer heating device to heat the pumped product internally and externally;

[0040] Step 3. Nitrogen filling for the first time: use the vacuum main pipe in the evacuation unit to slowly fill the product with high-purity hot nitrogen gas, observe the reading on the vacuum connection meter, and stop when the displayed value is greater than or equal to 0 inflated;

[0041] Step 4, the first suffocation: heat the inner and outer surfaces and the interlayer of the pumped product for several hours;

[0042] Step 5. Pre-vacuumize for the first time: When the inner and outer surfaces of the product to...

Embodiment 2

[0052] A vacuum degassing process, comprising the following steps:

[0053] Step 1, the pumped product is subjected to helium mass spectrometry leak detection;

[0054] Step 2. Install an evacuation unit, a temperature monitoring device, a vacuum connection meter, and an inner and outer frame heating device for the pumped product that has passed the leak detection; start the inner and outer heating device to heat the pumped product internally and externally;

[0055] Step 3. Nitrogen filling for the first time: use the vacuum main pipe in the evacuation unit to slowly fill the product with high-purity hot nitrogen gas, observe the reading on the vacuum connection meter, and stop when the displayed value is greater than or equal to 0 inflated;

[0056] Step 4, the first stuffy air: heat the inner and outer surfaces and the interlayer of the pumped product to 100°C-180°C, and the heating time is 15h-18h;

[0057] Step 5. Pre-vacuumize for the first time: When the inner and out...

Embodiment 3

[0067] This embodiment is basically the same as Embodiment 2, and its difference is that in the above-mentioned process preferably:

[0068] In step 3 and step 6, the temperature of the high-purity hot nitrogen charged is 80°C-100°C, and the nitrogen filling is completed within 10-15min; the nitrogen content of the high-purity hot nitrogen is greater than or Equal to 99.999%.

[0069] In step 4, preferably, the inner and outer surfaces and the interlayer of the pumped product are fully heated to 140°C-155°C, and the heating time is 16h;

[0070] In step 5, the pressure at the end of the vacuum main pipeline is 5Pa-1Pa; the exhaust time is 2h.

[0071] In step 7, after the aeration is completed, the pumped product is continuously heated to 140°C-155°C in the charged hot nitrogen gas, and the stuffy time is 1h.

[0072] In step 8, the exhaust time is preferably 1 h.

[0073] In step 10, the fourth suffocation time is controlled to be 4 hours, and the exhaust time of the fourt...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

A vacuumizing degassing process is disclosed. The process includes subjecting a product to be vacuumized to helium mass spectrum leakage detection, then inflating the product with high-purity hot nitrogen, thoroughly heating the product by adopting inside and outside heaters as auxiliary, performing inflation with hot nitrogen, gas sealing, and discharging hot washing in order to vacuumize to obtain low vacuum, vacuumizing in a manner of interrupted discharging to obtain high vacuum, and other steps. Through the steps and process parameters specific to the process steps, effects of removing residual gas in an interlayer for products processed through the process, such as vacuum insulated cryopump sumps, vacuum insulated cryogenic tubes and vacuum insulated cryogenic valve boxes, are extremely good, and therefore, heat leakage of vacuumized products during application is greatly reduced, and using performance and service lifetime of the products are greatly improved.

Description

technical field [0001] The invention relates to the technical field of vacuum product processing technology, in particular to a vacuum degassing technology. Background technique [0002] During the use of high-vacuum multi-layer insulation products, due to various factors such as outgassing of the material itself or vacuum leakage, etc., the vacuum degree may decrease, the thermal insulation performance will decrease, and the heat leakage rate will increase, which will cause energy consumption of the medium in the tube and may bring to safety hazards. [0003] Vacuum multilayer insulation is a very good insulation method. At present, this method is generally adopted for cryogenic storage tanks. This insulation structure requires the vacuum degree of the insulation interlayer to reach 1.33×10 - 2 Above Pa. However, due to the outgassing of the thermal insulation material, supporting structure and the inner and outer wall materials of the storage tank, the vacuum degree o...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Patents(China)
IPC IPC(8): F17C1/12F17C5/06F04B41/06F04B37/14
CPCF04B37/14F04B41/06F17C1/12F17C5/06F17C2203/0391F17C2209/23
Inventor 明长友邹波邹琴雒川
Owner CHENGDU CRAER CRYOGENIC EQUIP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap