? for Dan

Rudy

I work on a columbia CT-15 steam boiler and could use some info on sizing. The unit runs 8-10 hrs a day, six days a week. It has a field power ventorwith a 7 min. post purge. Two seconds after the vent shuts down the unit starts again. Is this oversized or can I extend the running time somehow. This laundrymat uses the steam at differant rates all day but normaly very fast. This unit has 100-200psi of steam to keep things running. Thanks for any help. P.S. this might be a good idea for a book, I would buy one.

John@Reliable_9

sorry not Dan but here goes...........

sounds like that "post purge" is to long! & 7 min. is just long enough that when pv shuts down you also have used enough steam to turn burner back on also. I would adjust powervent back to 1 min or so, why put all that stand by loss up the chimney. Better yet,call in a pro who understands dry cleaning boilers, because with-out it you are out of business! I stopped servicing them because all the calls were "emergency" calls seems like most cleaning plants never have the time for planned maintence. Hope this helps John@Reliable

Rudy

time

Thanks for the reply. The draft in the building is poor and we are fixing that. The 7 minpost purge is needed to get all the fumes out. This can be adjusted later but my question is more on the use of steam. I understand low psi steam and just want info on this type of steam. The dryers and machines use 100 psi in about 2 min. This changes all day. They also vent some outside----- why and this seems wastefull. thanks again.

Ken_8

You may want to look at the

differential setting of the pressuretrol.

Most of the power presses and related gear we see runs on between 60 to 140 psi.

With a spread that large, the "run" time should be long enough to prevent short cycling.

The purge time is grossly excessive. The post purge timing should be based upon scavenging time required - which with a HP Columbia would be more on the order of 30-45 seconds! Not 7 minutes!

I know the "smell" is the issue, but having a 7 minute post purge is completely unacceptable. The resulting short cycling, huge added fuel costs by completely avoidable post purge energy waste, coupled with wildly fluctuating operating pressure range can be solved easly.

If the boiler area is subject to building vacuum - simply isolate the boiler from the vacuum. This would be done by making sure the entire boiler is sealed properly; That the draft regulator be vented to the outside via inexpensive draft inlet vent extensions, and direct connection with outside air of the burner air intake "gate."

Assuming the Columbia is near an outside wall, horizontal fresh air venting arrangements would be easiest. In the alternate, the roof may afford a direct vent layout. In any event, if the byproducts of combustion are backdrafted when off, the chimney/stack has poor draft and/or the building vacuum is excessive and should be changed with something that gets things closer to neutral - or more than a stink may come from the chimney!

This is potentially a very bad situation. Especially on hot days when the presses/dryer/washers are also in play - and natural draft may become inverted!

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John@Reliable_9

Happy, fumes from boiler is really.....................

most likely air being pulled back thru boiler due to exhaust fans and dryers. Once had one that worked fine for years,then a restaurant opened next door. The exhaust fans from restauarant were pulling so hard that it pulled the heat from boiler out burner and caused coupling to melt causing no heat. Funny that was over 3 years ago and I still drive by in the winter and see the back door open to the cleaners, this was how we fixed it that day until we could install some make up air the next day. We show up with dampers to install and were told "already fixed" back door open, from that day on we no longer service unit!