high psi steam

EBEBRATT-Ed

I agree wit Mike -Steam traps but need to know more about the system.

ED

Mellow_2

Info needed

I have a columbia steam water heater (about 15 hp). It is runnning fine but I want to find out more about the steam parts of the system.......The water heater has a working psi of 100-175 pounds. This feeds a dry cleaners and runs about 14 machines..... The problem is the oil usage is high and the overflow at the end of the system is always venting outside. I see alot of waste and would like to find away to keep the steam in the system.......I need to know how this system should work and would like to see a book on this type of system but have not found one.....thanks for any help.......

c.t.kay

steam

check the steam flo rate required for each unit hooked to the steam supply line,put in orifice plates sized to the proper steam flo rate for each unit. check the piping and see if there is a return pipe to feed condensate back to the boiler.in many cases there is no return just a pipe to the atomsphere,there for the boiler just runs to maintain steam pressure,there fore using lots of fuel. insulate all steam piping with 2" fiberglsss insulation including the fittings,etc.call some one such as tunstall associates about steam traps,pumps etc.they can most likely send you in the right direction. remember this is high pressure steam treat it with care.

Mike20

Steam Traps?

Sounds to me like you have steam trap issues. A steam trap is supposed to keep steam separate from condensate water and if one or more are bleeding through this could be the source of the steam as well as your high fuel cost.
Also I agree with the call for insulation with a minimum of 2'' fiber glass. be sure to insulate all valves and fittings also insulate all supply and return lines ( most people do the straight pipe on the supply only)


I don't know if i understand exactly what you are saying about the water heater BUT if you are using High pressure steam to make domestic hot water, you are wasting tons of fuel for that process alone. There are much more efficient ways to produce Domestic hot water such as a dedicated high efficiency water heater

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Blackoakbob

Look at the ......

back of the machines and you will see the larger pipe going in and a smaller one coming out. The smaller one is the dead steam coming out. It has given up it's heat and condensed back to water. This process is controlled by some type of trap ( trapping steam and passing water). Look for a name on parts that you see at the back of the machine and refer to them on your next post here. Also, it would be helpfull to see some pictures of the equipment and the piping layout. Best Regards

Tony Conner

What Exactly...

... do you mean by "the overflow at the end of the system"? If it's the condensate tank vent, then a certain amount of steam discharging from it is normal. If it's roaring out, then that's not the way it should be. If you mean the tank is overflowing water, then that would indicate that the pump isn't working. This could be due to something simple like the float, or more involved, say if the pump has cavitated to death because failed steam traps are blowing live steam into the tank. If that nice hot condensate is not getting back to the boiler, then there's a big factor in fuel consumption. In steam of taking water at 180* and making it into steam, the boiler will have to take 50* makeup water to do the same job. There's 130 BTU per lb of water. Assuming the boiler is 80% efficient (proper boiler eff, NOT AFUE), then you'll have to burn 162.5 BTU more fuel for every lb of steam made by the cold makeup water as opposed to the hot condensate. This savings is over and above the avoided problems with scaling and corrosion that occur with a lot of makeup water.

Also, check the safety valve setting & nameplate info on the boiler. The safety should be set for no more than the maximum allowable pressure (MAWP) stamped on the nameplate. If it really is 175 PSIG (the safety valve CAN be set for pressures LESS than that), then everything in the system needs to be rated for that pressure - fittings, valves, trap bodies, etc. Anything rated for less - 125 CI or 150 malleable fittings for example, will not be permitted. (Loads of steam trap bodies are rated for 125 PSIG.)

Tony Conner

How...

... do you figure that the efficiency of HP steam heating water in a plant like this is poor, as compared to a "dedicated high efficiency water heater"? I disagree.

Show me the math.

Mellow_2

thanks for th reply

i WILL TRY TO GET PICS THIS WEEK.... The unit is a steam water heater (looks like a water heater but is a steam boiler).......The unit makes 150 pounds of steam to run dryers and steam machines..... the system has a condensate pump unit at the end of the main and it looks like traps on all the machines......when it is running steam is venting to the outside....not sure from where yet...will try to post again.......

Tom Blackwell

Laundries are notorious for lack of maintenance. The steam you see venting is probably coming from either a flash tank or a vented receiver. Laundry drier coils run wild- there is no temperature control. This means that the condensate at the bottom of the coil is saturated at the steam pressure. Once it passes the trap the superheated water flashes to steam because of the reduced pressure-this is normal for such a system, since the condensate/boiler feed pumps cannot handle water above 212 degrees. Normal design for such a system is to waste the flash steam. A flash condenser could be employed to preheat domestic water and may have an acceptable payback with $8.00 gas. In any event take a look at the traps and make sure none are blowing through. Gather more information and we'll try to steer you in the right direction.