Commercial Dryer Carbon Monoxide Seepage?

RickDelta

I'm trying to access the danger level of a service call today at a laundromat.
The complaint was poor and excessive drying times from many of the dryers.
Electronically everything was fine.
Total 40 stacked dryers

Two unusual observations:

One:
The outer rim edge mounted door seals were constantly "walking" themselves off their normal sealing positions. Often found halve hanging on the door or have dropped to the floor after customer opens the door. It became normal for staff to re-seat two or three door seals of different dryers every day.

Two:
The dryer drum itself has stamped hot air inlet holes on back wall of the drum. The front halve of the drum has stamped air exit holes around its diameter.
With an inspection light, looking into these front stamped holes, I could see lines (grooves) scrapped into the dryers air path containment envelope (metalwork) surrounding the rotating drum.
Many of the grooves actually penetrate this containment envelope making 8" to 12" narrow slits into this metal containment shell.
Staff tell me its common occurrence to see "drywall screws" finding their way into these stamped holes and getting entrapped, scrapping the envelope as the drum spins.

My concerns:
These seepage paths are allowing the heated air to reach areas not meant to be dealing with this exhaust air flow (front control panel, cabinet frame,etc) and seeping into the customer areas (carbon monoxide danger?).

The normally created negative blower air flow that normally "sucks" the door to stay close, is now upset and possibly aiding a positive air flow pressure to the front door seal, eventually walking the seal out of position.


........... thoughts on this?

ChrisJ

I would ask the manufacturer if anything. They would have a better idea than anyone, and not only that when they tell you it's a problem you can present that to the customer.

I'm assuming these are gas fired dryers?
I'm also assuming the venting is reasonable for the connected amount of equipment?

I've personally seen venting greatly effect dry times on my own small dryers.

RickDelta

@ChrisJ

I'm assuming these are gas fired dryers?
I'm also assuming the venting is reasonable for the connected amount of equipment?


Yes ....... gas dryers and good ducting.

Jamie Hall

Asking the manufacturer is a good first step. Or just looking at the installation literature. But a more do it yourself kind of step would be to investigate the air and combustion gas flows in the machines on your own. Where are there fans? Is the air sucked out of the drier drums into exhaust ducting? (Are those fans clean?) Or is the air pushed into the drier drums? How are the gas burners vented? Power vents? or are they under positive pressure? What is the pressure relationship between the combustion chambers and the air flow to the drums? Is the exhaust ducting for the drums completely separate from the exhaust ducting for the burners?

And so on...

leonz

Are these stacked units belt driven down draft fired Wascomats??

The door gaskets on these machines get old and stretch and need to be changed as needed, they are not a permanent gasket.

If the dryers heat exchanger shell is penetrated it will leak combustion gas and the dryer should be taken out of service and either repaired or replaced.

People leave crap in their pockets all the time and they end up in the drums and cause problems for the staff and owners.

The induced draft dryer fans are very powerful but lint accumulations and bad door gaskets will cause a great deal of problems and the stacked dryers lint drawers should be cleaned every day AND preferably the lint drawers should be removed and compressed air used with a high power shopvac to vacuum out any accumulated lint on and in the lint drawer rails occasionally.

The top of the upper drier also needs to have the lint removed with a thick wet cloth as well .

The flue piping needs to be pulled and the piping cleaned with a chimney brush as well.

Been there done that.

RickDelta

@leonz @Jamie Hall @chrisJ

I hear ya guys! ..... all good stuff!

Are these stacked units belt driven down draft fired Wascomats??

Yes!

People leave crap in their pockets all the time and they end up in the drums and cause problems for the staff and owners.

They must have a large contractor customer base, "drywall screws" and "nails" all over the place! I think i'll have to put in airport style metal detectors at the main entrance! LOL! : )

But, really, I'm thinking of simply installing high temperature Neodymium magnets in the drum to catch metals before they find a path to harms way.

mattmia2

leonz said:

People leave crap in their pockets all the time and they end up in the drums and cause problems for the staff and owners.

If that can compromise the HX that sounds like a recall worthy design defect. Laundry having stuff in the pockets that isn't removed is about as expected an operating condition as the laundry being wet.

RickDelta

@leonz

If that can compromise the HX that sounds like a recall worthy design defect.

Good point!
The clearance between the drum and the heat exchanger shell surround is only about 1/2" !! a common size drywall screw can easily bridge this gap and jam in.

I'm looking at our dryers here, and the gap is twice this distance. Much more tolerant to errant metal objects poking in.

leonz

The gap is there to allow air flow from the top of the driers burners around the rotating drum, through the lint drawer and out the exhaust flue.

People are supposed to check their pockets before they even put the clothes in the washer!!!!!!!!!!!!!!!!!!!!!!

The laundromat owner needs to put up signs to help stop this crap from being put in washers and driers.

This crap can keep solenoid powered clamp drainage valves from closing and spilling clean water and not
filling the washer to finish its first cycle.

You can't find parts at the local NAPA to fix stupid.

They talk about this issue in the laundromat business magazines often.

Keep in mind that if you put a magnet in there they won't remove anything that is attached
to it and the next customer will have damaged clothing.

RickDelta

@leonz

The metal air flow containment surround is part of the machines superstructure and pop riveted together. Its not a "replaceable" separate item.

All the dryers have at least one air plenum breached "groove" slit.

Replace all 40 dryers with new ones? ....... not likely! They called me for a work around solution.

I'm pondering this:
Remove drum from machine
Pop rivet "metal roof flashing" over the "scores" / "grooves" or High temperature foil tape.

Install high temperature Neodymium magnets to the three tumble paddles in the drum.


........ your thoughts to this?

leonz

RickDelta said:

@leonz

The metal air flow containment surround is part of the machines superstructure and pop riveted together. Its not a "replaceable" separate item.

( I know that)

All the dryers have at least one air plenum breached "groove" slit.

(Your not talking about the wide air opening over the lint drawer are you??)


Replace all 40 dryers with new ones? ....... not likely! They called me for a work around solution.

ehhh, see below

I'm pondering this:
Remove drum from machine
Pop rivet "metal roof flashing" over the "scores" / "grooves" or High temperature foil tape.

Install high temperature Neodymium magnets to the three tumble paddles in the drum.


........ your thoughts to this?

NOPE, NOPE, NOPE, UH, UH, NYET, NINE, that is UNLESS you want to replace all the stacked roller bearings in each dryer while your doing this as a complete tear down from the rear is required for these dryer drums to remove them from the front.

The glue on the tape will make a mess on the clothes.......................................

The dryer drum is surrounded by the heat and the exhaust stream passing through to the lint drawer to the flue piping.

The magnets will simply catch anything and the customer following the last one will have damaged clothing.

Walkaway and tell them to call their insurance agent to see if this damaged is covered and then call their Wascomat distributor.

RickDelta

@leonz
.....that is UNLESS you want to replace all the stacked roller bearings in each dryer while your doing this as a complete tear down from the rear is required for these dryer drums to remove them from the front.

All the roller bearings are fine! .... why replace them?? : (
"Popping" the drums out is cake on these machines! I have a small dedicated tool set I leave onsite that instantly releases the belt tension, cordless drill with required torx bits and socket wrench (works fast like an Indy500 pit crew!)


The glue on the tape will make a mess on the clothes


3M™ High Temperature Flue Tape is a thin foil tape designed to prevent air leaks at the seams of your heating ducts.
Stops hot air leaks where they start – the seams of your heating ducts. The flue tape is heat resistant up to 600° F (I don't see the dryer heat affecting this glue in any way).


The magnets will simply catch anything and the customer following the last one will have damaged clothing.


We set up a test dryer today with the 6 magnets (3/4" disk) attached to the 3 drum paddles (total 18 magnets).
It was amazing! ......
Empty drum + handful (12 count) of 1" drywall screws: All captured in one and halve rotations! metallic "clanging" gone too!
Girls panties + handful screws: No attachment No damage
Hand towels + handful screws: No attachment No damage
Random mix + handful screws: No attachment No damage

....... the drywall screws lay flat against the drum out of harms way.
The magnets holds the points of the screws "nose down" against the drum.

Staff will run test loads for the next few days, but I think we have a reasonable solution.