Steam Jet Air Ejector assistance
Steam Jet Air Ejector assistance
(OP)
Due to me volunteering (idiot!) I've been tasked with investigating why our SJAEs aren't functioning as they should. We run 2 100% duty ejectors, supplied by Nash Weineck, but for the last 8-10 years have had to run them in parallel under all load conditions to maintain vacuum in our condenser (16 year-old 360MW combined-cycle power station). In previous years the steam side has been stripped & inspected but the water side has been left alone. The inlet steam conditions are always consistent and the water flow through the ejectors is at 12 barG and around 40 degC.
I am going to contact SVS STRAHLPUMPEN und VAKUUM SYSTEME GmbH & Co.KG, Weineck's successor, but wondered if there was anyone else I could try that was UK-based?
I am going to contact SVS STRAHLPUMPEN und VAKUUM SYSTEME GmbH & Co.KG, Weineck's successor, but wondered if there was anyone else I could try that was UK-based?





RE: Steam Jet Air Ejector assistance
Best of luck!
RE: Steam Jet Air Ejector assistance
We also don't have any way of measuring condensate flow to drain from the steam side of the condensers so we could well have a tube leak and not know about it.
RE: Steam Jet Air Ejector assistance
Has anything materially changed with respect to the after condensers (plugged tubes, fouling, cooling water source or temperature or flow)?
Jets are pretty steady state devices and if they are operating within their design parameters they will usually either work or not. If not, it is something wrong with the jet itself, such as nozzle wear or leakage of the motive steam around the nozzle threads. You might want to consider a nozzle replacement. If the answer to the first question above is yes in that the motive steam is not what the jet was originally designed for (different pressure, more or less superheat, etc) then you guaranteed want a nozzle change.
Try this. Shut off the suction to the condenser momentarily and see if the jet (or jets) will pull down to a deep vacuum. If not, it is the jets. If you can't do this because the condenser back pressure climbs too high while the jets are isolated, then it is guaranteed your leakage rate is more than the jets can pull out. If the jets pull down to a deep vacuum then again it is your inleakage overrunning your jets.
Give it a try. What I have suggested is an old trick used by Jet service engineers to get a quick look for a place to start because if the jets are working, their reaction is very predictable-they will pull down quickly.
rmw
RE: Steam Jet Air Ejector assistance
Between rmw's suggestion and this you will have a better picture of what is happening.
My money is on severe air inleakage.
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Plymouth Tube
RE: Steam Jet Air Ejector assistance
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