"typical" steam losses in a hospital
"typical" steam losses in a hospital
(OP)
I know every building is unique and rules of thumb can be a dangerous thing, but I am only trying to get an order of magnitude here. I have a large hospital with a high pressure steam boiler plant that is losing a lot of water. I don't have actual numbers back, but trends are being recorded. There are a lot of politics involved here, so the solution is not as simple as just going around and making sure condensate isn't being dumped to drain. I am in fact fairly certain that condensate is being dumped, so I am trying to put a quantity on it.
Given that we are in the summer now, I don't have any humidifier losses. As far as I know, sterilizer steam condensate comes back to the boiler plant, so I am thinking that my only significant loss should be from the deaerator vent and any flash tank and condensate receiver vents. All other condensate should come back to the plant. Am I missing anything?
With that in mind, is there a way to estimate the quantity of steam that I am losing through the vents in terms of a percentage of the overall plant capacity? I would guess no more than 2-3%, but I have nothing to back that up.
Any thoughts?
Thanks
Given that we are in the summer now, I don't have any humidifier losses. As far as I know, sterilizer steam condensate comes back to the boiler plant, so I am thinking that my only significant loss should be from the deaerator vent and any flash tank and condensate receiver vents. All other condensate should come back to the plant. Am I missing anything?
With that in mind, is there a way to estimate the quantity of steam that I am losing through the vents in terms of a percentage of the overall plant capacity? I would guess no more than 2-3%, but I have nothing to back that up.
Any thoughts?
Thanks





RE: "typical" steam losses in a hospital
RE: "typical" steam losses in a hospital
RE: "typical" steam losses in a hospital
RE: "typical" steam losses in a hospital
RE: "typical" steam losses in a hospital
Not sure why anyone would be surprised by direct steam injection for humidification as long as FDA amines are used. That is a very common practice. I don't recommend it as there is no control for airborne levels from OSHA and ACGIH, only for FDA ingestion levels.
If the boiler is old or does not have a good turndown ratio, at leat 8:1 for #2, I'd also recommend looking at peak load vs. summer load to see if a summer boiler is justified. In the middle of construction for an energy project based on summer boiler savings, so that could be the source. Is loss percentage comparable between summer and winter?
RE: "typical" steam losses in a hospital
RE: "typical" steam losses in a hospital
RE: "typical" steam losses in a hospital
RE: "typical" steam losses in a hospital
Side anecdote, local hospital had much more condensate return than steam supplied. WTF, right? Turned out there were so many traps blowing by that they ran city water into condensate receivers to quench the steam/water mix so pumps wouldn’t cavitate and could return water to the plant…
Hmmm…
RE: "typical" steam losses in a hospital
So, my purpose of asking the question was to try to gauge what the ideal losses of a plant should be through vents, blowdown, etc. In other words, if everything was running perfectly, how much make up water should I expect?
RE: "typical" steam losses in a hospital
Just that routine trap maintenance and insulation upkeep is an easy payback.
RE: "typical" steam losses in a hospital
I would like to add a word about the clean steam issue between Ross and Urgross:
I read a study long time ago by the US Army COE regarding this topic of amines.
The study found that even non FDA approved chemicals when metered provide TLV's below FDA max levels. The study found that systems using daily one-shot injection to be problematic, as the hour following the chemical injection results into 7 to 10 times the amine TLV levels, only to be normal towards the end of the day.
The key is to meter chemical injection based on alcalinity.
Someone wrote an article in ASHRAE about clean steam and scared the hell out of the industry.
RE: "typical" steam losses in a hospital
Someone at DriSteem???
RE: "typical" steam losses in a hospital
Cry22,
What can FDA ingestion standards (which in all honesty should only be applicable to Nutrition & Food Service and Canteen) have to do with airborne inhalation standards? The levels given by ACGIH and OSHA for airborne cannot be controlled by pH, and I have seen no publication or knowledgeablke operater that has said different. ASHRAE published the 1998 design manual for hospitals and clinics which expresses this argument quite well. Certain sections of the hospital, such as pharmacy, should already be following that standard based on ISPE.
BronYaur,
A little more information is needed. Do you distribute at high pressure, then use PRV's to provide operable (60-psig, 30-psig) steam, then return all pressure gauges of condensate back to an atmospheric receiver? That would be common practice in comparison to directly piping all pressures back to DA tank for vent. If using common atmospheric tanks, you are probably losing about 10-12% flash steam at those locations.
RE: "typical" steam losses in a hospital