Cryogenic double-walled vacuum jacket pipeline
What is a vacuum jacket (cryogenic transfer tube)?
In the first part, the pipe is double-walled, which is made using MLI super-insulated radiant insulation, along with safety equipment, drain valves and flexible connections.
In the second part, the insulation on this pipe and the type of its coating are of great importance
In general, due to the high level of technical knowledge, special type of design, insulation, high vacuum level and the rate of temperature change, this equipment can be considered a small cryogenic tank.
Vacuum jackets are used to transfer liquid oxygen, liquid nitrogen (liquid nitrogen) and LNG.
The reason for using this equipment in the transfer of cryogenic fluids is the very low temperature of this fluid. For example, if we want to transfer the liquid nitrogen produced by the cold box to the storage tank, if we use a single-walled tube or a non-standard jacket vacuum, this The fluid with temperature (-196) leads to heat transfer and evaporates to a certain extent, which causes the storage tank pressure to rise, which is not desirable.
Question 1: In what cases is the use of a vacuum jacket (vacuum jacket) recommended?
– In general, when the consumer needs cryogenic liquid at the outlet of the tank or equipment and does not remove gas from the main equipment.
-If the cryogenic fluid transfer time in the pipeline is more than 8 hours per day.
– In cases where the presence of liquid at the place of consumption is important, such as the IQF device.
In cases where cryogenic fluid transfer is important, such as coldbox transfer.
– In cases where the fluid is connected to a cryogenic pump.
Question 2: In what cases is the use of a vacuum jacket (vacuum jacket) not recommended?
-If the outlet is a tank or gas equipment and the consumer needs gas.
In cases such as draining the kerogenic fluid from the transport tank to the fixed tank.
Pishran Zomhrir Aseman Company, with its experience and ability to design various types of vacuum jackets (Cryogenic pipe) based on the standard, has been able to provide desirable services to industrial and non-industrial complexes.
(وپورایزر یا اوپراتور) مبدل حرارتی چیست؟
Vaporizer or heat exchanger is a device that can convert gas condensate such as nitrogen, oxygen, argon and… from liquid to gas without the need for electricity, water, etc. Using the air flow. The ambient temperature is the temperature of the fluid, so that the liquid passes through the tube connected to the fin and changes the state of the liquid to the gas. has it.
There are several important points to consider when choosing a veterinarian:
1- The amount of liquid inlet flow rate and the desired gas flow rate
2. Type of fluid
3. Operating time
4. Operating pressure
5. The lowest ambient temperature at the installation site
Operator design:When designing the operator, attention should be paid to the type of blade and the amount of indentation, and the length of the blades. Vaporizers are generally made of aluminum and their maximum pressure is in the range of 1 to 25 times. If the need for pressure higher than this value should be used steel pipes with appropriate specifications.
نحوه ورودی اوپراتور ها به دو صورت می باشد:
1-نوع اول:زمانی که مایع درون اوپراتور وارد می شود تمامی لوله ها را طی می کند تا از کانکشن خروجی خارج می گردد.
2-نوع دوم: در این مدل یک کلکتور وجود دارد که مایع در این لوله اصلی وارد می شود و سپس در پره ها به صورت موازی حرکت می کند تا در کلکتور پایانی مجددا تمامی گاز ها به هم متصل شوند.
سوال1:فشار کاری اوپراتور چگونه مشخص می شود؟
فشار کاری اوپراتور با فشار مخزن برابر می باشد.برخی به اشتباه تصور می کنند که چون مایع در این دستگاه تبدیل به گاز می شود فشار در خروجی بالاتر از ورودی می باشد.دلیل یکسان بودن فشار اتصال مخزن و وپرایزر می باشد.
سوال2:در چه صورت برای اوپراتور مشکل پییش می آید؟
در صورتیکه مایع کرایوجنیک در اوپراتور باشد و شیر برداشت مایع بسته شود و در خروجی هم شیر بسته شود مایع در این بین حبس شده و تبدیل به گاز می گردد که این امر موجب افزایش فشار بیش از حد شده و احتمال آسیب را بالا می برد.
سوال 3:در چه مواردی استفاده از وپورایزر توصیه نمی شود؟
اول -در زمانی که میزان پرت(میزان روزانه تبدیل مایع به گاز) مخزن بالاتر از میزان مصرف باشد.
دوم-در زمانی که مخزن مجهز به کویل فشار ساز باشد و میزان مصرف کمتر از ضریب اعلام شده کویل فشار ساز باشد.(این عدد در مخازن شرکت زمهریر 400 کیلوگرم در روز می باشد)
شرکت پیشران زمهریر آسمان با توانایی و تجربه طراحی انواع وپورایزر ها در خدمت صنعت میهن عزیزمان می باشد
تعمیر مخزن کرایوژنیک
Due to the complexity and double wall of cryogenic tanks, repairing this tank is a very specialized job.
Lack of access to the internal tank and pipes between the two walls makes this much more difficult. In repairing the tank, special attention should be paid to the year of construction of the tank and its service life. Be.
The following points should be considered for repairing a cryogenic reservoir:
1-year of tank construction
2. The actual value of the tank
3. Estimate the cost of repairs
4- Reason for repair (can it be continued with this problem)
5. Defect detection in internal or external tank
levels Tank repair Cryogenic
Using various tests, it must first be determined whether there is a problem or leak from the internal tank or the external tank.
1- If the problem is in the external tank, first the exact point should be determined and the defects should be eliminated using the usual methods and the tests should be repeated.
The result of the work is determined after filling and emptying the tank several times and measuring the amount of vacuum.
Vacuum or insulation loss
If the vacuum of the tank is closed, the tank must first be vacuumed to determine the amount of leakage.
If there is no leakage, the vacuum of the tank is checked for a long time in both dry and liquid states.
Charging perlite can also be fruitful if the tank is of the perlite insulation type.
The most difficult case to repair a cryogenic tank is when there is a defect in the internal steel tank. It is easier to work in a tank where there is a place to enter. Otherwise, the external tank and the internal tank must be separated for repairs. It should be done on the internal tank. These repairs should be done in highly specialized companies, because of this type of tank design.
Pipes and fittings
Failure of pipes and fittings is less common in fixed and standing tanks, but is more likely in carrying tanks.
In these cases, the necessary tests should be performed on the tank to identify the defect and eliminate the defect using conventional methods.
It should be noted that this company with the ability and experience of manufacturing and designing tanks from 1 to 220 tons has the ability to build any type of tank with any pressure on demand.
The construction time of cryogenic tanks with a capacity of less than 30 tons is about (4 months) and the construction time of cryogenic tanks more than 30 is about (6 to 8 months).