Ventilation question.

[colly0410]

At all the pits I've been to in Notts (underground at Moorgreen & Hucknall, surface visits at many others) the ventilation was by an exhaust fan in the upcast shaft. Did any pits use the opposite method e.g. blowing air into the downcast shaft?

[John]

Jun 27, 2012 7:10:48 GMT -5 colly0410 said:

At all the pits I've been to in Notts (underground at Moorgreen & Hucknall, surface visits at many others) the ventilation was by an exhaust fan in the upcast shaft. Did any pits use the opposite method e.g. blowing air into the downcast shaft?

Whoops, first thing in the morning for me...


Not that I'm aware of within coal mining, but CPL at it's Boulby mine blows air down these days, I can't see the reasoning though as it goes against old established standards.
I can understand why they brought the fan to surface though.
When I started there in early 75, the fan was on the surface blowing air down four vent tubes during the development stages, then two fan chambers were developed underground on either side of No1 shaft to form a "balanced ventilation scheme" and we extracted air from the mine and blew it up No1 shaft.
This eliminated the need for air locks on the towers.
Problem was floor lift under the fans, even though the fan motors, 1350HP each, were on a heavy bedframe with the fan coupling and fan mountings, floor lift caused bearing problems due to throwing the fan shaft out of alignment with motor shafts.
With that sort of HP, the bedframe had to be bolted to the very thick reinforced concrete floor, but nature took it's course...

[colly0410]

There must be a good reason for sucking air out the upcast shaft, I was probably told at the training centre but I must have forgot, well it was a long time ago.

[John]

Forcing, or compressing air does create heat, that's the only logical reason I can see why it's not done very often.
Creating a low pressure region, ie extracting, doesn't.

[colly0410]

Good point John, I call it the bike pump effect.

I've been thinking (yes I know, I'll wear my brain out ;D). If air is sucked out of the mine the pressure underground will drop, if the fan stops for some reason the pressure will rise, so forcing firedamp, blackdamp or any other sort of damp back into the strata, so increasing the time before gas becomes a problem. If the blow methods used you don't get that advantage. Just a random thought.

[bibobs]

Yes Gedling had Homotropal ventilation I know of no other in Notts but it is possible. This system was used to minmise dust
problems, air went down the tailgate and up the loader gate all coal clearence on return No 1 intake No 2 return
Bibobs

[bibobs]

Qualify last reply
by the 1960s Gedling had over 20 miles of ventilated roadways to improve the system two banks of Boosterfans were installed
3 in constant use 3 on standby i e maintanance no air was blown down the shafts normal fan drift at No 2 shaft
Bibobs

[dazbt]

I think one of the advantages of homotropal ventilation was that it reduced temperatures and humidity problems on coal faces, the idea was that the heat and moisture of the coal in transfer was not carried back into the working face.

[colly0410]

Thanks for info Bibobs.

My Wife's Uncle Eric worked down Gedling, he was telling me how the electric train used the intake & the conveyors, transfer points & other gubbins used the return. He's got a booklet on the electric train, I'll try & scan it & put it on here, unless copyrights forbid it.

[John]

Jun 28, 2012 9:28:00 GMT -5 colly0410 said:

Thanks for info Bibobs.

My Wife's Uncle Eric worked down Gedling, he was telling me how the electric train used the intake & the conveyors, transfer points & other gubbins used the return. He's got a booklet on the electric train, I'll try & scan it & put it on here, unless copyrights forbid it.

The only thing I ask about placing material on the site is everyone acknowledges the source, that way there should be no problem. The site is also hosted in the US, so copyright laws are different, ie I can post an entire book, minus a couple of pages, as long as it's not for profit.
Plus if it's en old NCB booklet, there should be no problem these days as the NCB doesn't exist anymore.
You will have to scan it and post the pages to a site like Photobucket or Flickr, then direct link them ie post them as IMG files, Photobucket allows you to copy one of three files, "IMG" :"Direct Link" or "URL", use the "IMG", copy it and paste it directly on your post.

[colly0410]

OK John, I'll ask Uncle Eric for the loan of the booklet next time I see him.

[colly0410]

With all the advantages of homotropal ventilation I wonder why most pits still had stage loaders, belts, transfer points ect in the intake roads? Was there any advantage to this?

On the Gedling electric train booklet thing: I saw Uncle Eric a few months ago but forgot to ask him if I could borrow it, you know how dozy I am sometimes..

[John]

Feb 7, 2015 12:31:10 GMT -5 colly0410 said:

With all the advantages of homotropal ventilation I wonder why most pits still had stage loaders, belts, transfer points ect in the intake roads? Was there any advantage to this?

On the Gedling electric train booklet thing: I saw Uncle Eric a few months ago but forgot to ask him if I could borrow it, you know how dozy I am sometimes..

Could it have been on safety grounds?? All methane drained into the returns, friction heating from a belt, high CH4, boom?? That's the only thing I can think of.
But, some pits had belts in the returns for backripping and dinting, so kind of negates what I said.

Boulby had all it's belts in the returns.

[rob52]

Ventilation Systems

Pg15 discusses the advantages & disadvantages
1) Exhausting System
2) Blowing System

Rob

[colly0410]

Thanks for that link Rob, I'm off out in a few mins to put flowers on Mam & Dads grave, but I'll have a read through it later...