Steam Jet Refrigeration
Steam Jet Refrigeration
(OP)
Does anyone with practical experience relating to steam jet cooling have pro's and con's on how the system performs? This pertains to chilled water systems producing 500 to 1,000 tons of cooling at 45 °F.





RE: Steam Jet Refrigeration
They are physically large, heavy machines for their output, as compared to screws or centifugals. They also require more cooling tower capacity per ton of chilling.
The biggest electrical motor on a 500 ton absorber will be a solution pump motor that's about 15 HP.
RE: Steam Jet Refrigeration
Steam jet refrigeration uses a steam ejector system to pull vacuum on a flash evaporation tank. In the case of 45 °F temperature, it will operate at 7.63 mmHg (abs). Typically it will require a 3 stage ejector system with intercondensors between the stages to lower steam usage. The return water is circulated through the flash tank, where a portion of it spontaneously boils off due to the low pressure. The ejector system removes this vapor as well as any non-condensible gases.
My question pertains mainly as to how capacity is controlled in this type of system, as well as any common problems.
From what I've gathered, these systems are used primarily in industrial installations where equipment reliability outweighs operating costs. In the past (before 1930) there were some commercial HVAC applications.
RE: Steam Jet Refrigeration
We were having problems with vacuum pumps on some absorbers in a plant where I worked (not the fault of the pumps, but nasty old, poorly maintained absorbers) and I looked into staging ejectors for this function. It was the same kind of vacuum required, and I was going to need 3 stages. The cost was going to be just nuts, so we stuck with the conventional pumps.
RE: Steam Jet Refrigeration
From additional information I've found, these systems appear to be mostly obsolete. The combination of factors that make them economical are cheap steam at 100-150 PSIG, expensive electricity, and cheap and plentiful cooling water supply. Outside of process applications with these conditions, they are not economical. There is 2-3 pages of information on these systems in Perry's Chemical Engineers Handbook.
RE: Steam Jet Refrigeration
I'd never heard of "steam jet cooling" before. I'll check out the write-up in Perry's. Thanks.
RE: Steam Jet Refrigeration
I know that Chill Vactors are very reliable in operation. Maintenance is also very easy, there are effectively no moving parts on the chiller itself and any repairs to the chiller (vacuum leaks primarily) can be performed by a certified welder. There is no refrigerant used, which is a big bonus environmentally. They do require a little larger cooling tower than a comparibly sized absorption chiller and they usually must be free standing outside and have a larger foot print than an absorption chiller.
These units can usually put out chilled water at most any design temperature (I think they can be designed to output at least 40 degree water).
As was said in previous posts, excess steam is required. Usually a power plant or industrial plant with a lot of steam generation can support a chill-vactor. Usually summer time venting of medium pressure steam would indicate a possibility to apply this process. If you have to generate excess steam to support this, it's not worth it.
These chillers are what I would label as "old school". They use proven low maintenance technology to give you quality chilled water supply. They are not for every application. If they are right for your application, there will be many that think they are not the answer because they are not commonly supplied. Stick to your guns. Maintenance has a very high cost especially on absorption chillers.
RE: Steam Jet Refrigeration
RE: Steam Jet Refrigeration
Kindly please sent me a quotation for the Hot water Venturi Ejector.
Venturi Ejector:
Design Pressure: 15 kg/cm2G
Design Temp: 190 degree
Pressure drop: 0.5 kg/cm2G
Water Inlet:
Flow rate: 120 m3/hr
pressure: 13.5 kg/cm2G
temperature: 84 degree
Water Outlet:
Pressure: 13 kg/cm3G
Temperature: 91 degree
Steam Inlet:
Density: 4.2
Flow rate: 0 - 1, 270 kg/ hr
Pressure: 7 kg/cm2 G
temperature: 170
Material Construction: SUS 304
Insulation: yes
Connection Size:
Water side 6" ANSI 300# RF, Steam side 3" ANSI 300# RF
Thank you and we hope to hear from you by today.
Best regards,
Cheah
socheah@hotmail.com