My week this week! My workshop videos.

[hermetic]

Hi Chaps, many of you have suggested that I post all my videos in one thread, and I have decided to give it a go and see how it works out. From now on I will post in this thread every week, starting with these offerings. As usual some things go right, and some don't. You do have to be carefull with the Gopro as the tiny touch screen makes it really easy to touch the wrong button without noticing, hence there is a second slideshow of the pics I took when I thought I was shooting video. I think a second camera may be on the cards! Hope you enjoy these, and remember to like, comment, and subscribe! Thanks for watching!

https://youtu.be/-za-j8vKqdc

https://youtu.be/B0TkR4xo4ZI

[Doozer]

Cool forge setup. Is the insulation seal so tight in your shop that perhaps your shop is under vacuum, and hence no flow to the draft?? Just a thought.

--Doozer

[hermetic]

No Doozer, that is not the problem, the blue roller shutter is not sealed at all, and the wind blows in! The flue/ flue fan is fine for the workshop woodstove and the brazing hearth, but it need much more suckiness for the amount of smoke from the forge, at least when it is being lit, although if I dispensed with the paper and sticks, and used a gas poker, that might get it alight, BUT the CO alarm went off, and that means that CO is escaping rather than going up the flue, and that is a complete nono!
Thanks for commenting.
Phil

[hermetic]

Just to add to the problems, the main flue fan quit today! that gives me the opportunuty to fit a bigger one. The heater will actually run very happily without it once lit, but I will brave the cold (or use electric heat) while I rebuild it with a new motor. See what tommorow brings!
Phil

[hermetic]

Hi chaps! Not much time spent in the workshop this week, but managed to get a bit done, failures and succeses!¬ and as an added bonus, a car repair, you can't be without a heater this weather! Enjoy, and subscribe if you like it!
Phil
East Yorkshire.

https://youtu.be/5AWovKfPW7o

https://www.youtube.com/watch?v=cWhJLKaMd9A

[Franz©]

First thing I noticed in the flu induction blower is it appears off center. Such systems function best when the added air into the smoke stream is added centered coaxially.

That's step 1 in the inductor.
Step 2, the air pipe must extend into the smoke pipe beyond the 90° turn - there is no hard and fast rule on how far so generally the air pipe will be mounted in a collar so adjustment can be made for best flow.

The ratio of diameter air pipe / smoke pipe is hard and fast if you want performance. The air pipe MUST occupy at discharge into the smoke stream 1/3 of the smoke pipe dimension. This can be done with a conical discharge if no convenient pipe ratio is available.

The pressure of the air stream arriving in the smoke pipe will govern speed of smoke departure.

[hermetic]

First thing I noticed in the flu induction blower is it appears off center. Such systems function best when the added air into the smoke stream is added centered coaxially.

That's step 1 in the inductor.
Step 2, the air pipe must extend into the smoke pipe beyond the 90° turn - there is no hard and fast rule on how far so generally the air pipe will be mounted in a collar so adjustment can be made for best flow.

The ratio of diameter air pipe / smoke pipe is hard and fast if you want performance. The air pipe MUST occupy at discharge into the smoke stream 1/3 of the smoke pipe dimension. This can be done with a conical discharge if no convenient pipe ratio is available.

The pressure of the air stream arriving in the smoke pipe will govern speed of smoke departure.

Thanks Franz, that is good information! The pipe from the fan does go into the centre of the outlet pipe although it looks nearer the bottom, inside, it isnt. It does go round the bend and up the vertical pipe, and I can do some measurements to check, but it is a 2" pipe at least. I am removing the H top from the flue and replacing it with a higher straight outlet with a dome cowl, as I think the H may be causing turbulence when the air hits the flat wall of the bar between the two uprights of the H. I am fitting a more powerfull motor with a speed control, and when using this I can throttle the flue on the workshop heater, and also let more air in to the system by using the brazing hearth hood as an auxillary air inlet. I think I made a major mistake when I fitted the air blower for the heating in the blacksmiths shop, as it picks up smoke and smells (and CO!!!) and blows it into the workshop, hence the CO alarm going off! I had all the doors open, and should have done a reset on it, but didnt realise that it needed a reset after every triggering. Thanks for watching and commenting, All information is always usefull!

Phil
East Yorkshire.

[Franz©]

I'd definitely loose the H. That alone will increase your natural draft.

If possible I'd also locate the blower inducer straight up from bottom of the stack rather than running it thru the horizontal pipe. The horizontal element may become a fine condenser for tars and potential fire starter.

Also you might want to experiment a bit with curtains for want of better nomenclature to lessen the space the hood has to draw from over the forge pan. That along with eliminating the H should increase your draft.

[hermetic]

Hi all, as usual, I didnt get s full week in the workshop this week, but fitted s new motor to the old fan housing, which is much more powerful, and very effi9cient, but I heed to modify the flue as well before I can tell if the problem is solved. It certainly works better than it did! Enjoy, like and comment , and as usual thanks to you all for taking an interest in my channel and thanks and welcome to all the new subscribers!
Phil
East Yorkshire

Video link

https://youtu.be/Rgoji6X9Klo

[hermetic]

I'd definitely loose the H. That alone will increase your natural draft.

If possible I'd also locate the blower inducer straight up from bottom of the stack rather than running it thru the horizontal pipe. The horizontal element may become a fine condenser for tars and potential fire starter.

Also you might want to experiment a bit with curtains for want of better nomenclature to lessen the space the hood has to draw from over the forge pan. That along with eliminating the H should increase your draft.

Thanks once again Franz, I had considered putting the fan in the bottom of the vertical flue, but didnt as it would mean waterproofing it, and also I have a condensate drain in the bottom of the vertical pipe, certainly a possibility with a bit of re-jigging though. The horizontal flue through the wall is only about 9" long, and I am going to insulate all the internal flue with rockwool. The heater is working much better now that the whole thing, including the flue, is running hotter. Most of what runs out is clear water, with a very thin oily film, and as my wood moisture content falls, that is improving too. It is a matter of allowing the heat exchanger to remain hot enough to prevent condensate forming, and of maintaining a hot quick fire in the grate! Yes, already considered some curtains to reduce the area of the forge hood, another good idea, thank you!!
Phil
East Yorkshire

[J Tiers]

I think I know what your forge issue is. It is in the hood design.

You have a fairly small pipe, and a large opening in the flue. The air velocity at the face of the hood is going to be very low, because of the difference in area of the pipe and the large hood opening.

What is usually done is to actually block up most of the inside of the flue, such as with a plate that covers the center part of the hood, leaving a space around the outside of perhaps an inch or so, depending on what the possible flow is up the flue.

Yes, it sounds totally wrong... but the idea is to get a higher air velocity around the outside, so when "smoke" tries to leak out around the outside, it is rapidly sucked up the slot by the relatively high velocity flow. It really works pretty darn well, but you do need to have the area of the flue and the area of the "slot" around the hood matched up so there is a good air velocity there.

usually, the plate is a little way up inside the hood, an inch or two, to help capture the "smoke".

I ought to add that the cubic feet/minute of the exhaust setup ought to exceed the cubic feet per minute of the blast fan, or you will over-run the exhaust with blast. That would guarantee that CO etc will be in the room.

[hermetic]

Hi J Tiers, I think you are right, I have pushed the envelope a bit too far! The actual flue diameter of the forge hood is 10", I have reduced this to 7", and hoped that the forced flue would make up for the reduced area. I like the idea of blocking the centre of the hood to increase the velocity around the outside, I will try that in the near future. As you have seen the new flue fan is MUCH more powerful, but I want to change the flue outside to a straight pipe with a top cowl rather than the H pot and see what the effects of that are before I go any further. I will also be following up Franz's suggestion of fan outlet area to flue area ratio. I think most of the CO problem was caused by me burning furnace ovals rather than coke, when I lit the forge before, just on coke, it smoked, but the CO alarm did not go off. On further investigation I find that furnace ovals are for closed furnace use only, I should have got the "open fire" type. What I really want is some proper forge breeze, or coke beans, and I have a few sources to contact next week. I will be taking the ovals out of the forge before I try to relight it! Thanks for watching and commenting, every day is a school day, and I am learning all the time!
Phil
East Yorkshire

[OaklandGB]

I think Franz touched on the problem. There might be way too much opening for the flue size. Franz mentioned side curtains to cut down on the open area feeding the flue. While I am not an engineer, I've read about fireplace designs and the opening size always seems to be a major concern for good draft. Get it too big, and the air pulled in by the heated gases will overwhelm the flue pipe causing spillage out of the firebox. You seem to have this issue.

Perhaps as an experiment, you could tack some sheet metal to close up the open sides, leaving just the front open and see if that helps. If it does, maybe some removable curtains. If it doesn't take the temporary walls down and continue on.

In any case, thank you for posting this, it is great that you share your experiences so we can all learn.

Good luck Phil!!

Gary

[hermetic]

Thanks for the comments Gary, I finished the flue extension today, and will start the fitting tomorrow, if it doesnt rain. I am going to remove the H pot, set up the blower outlet as Franz suggested, then fit the flue extension. It will add about six or seven feet to the chimney height, depending on how much overlap I can get. It will all be in next weeks video!
Thanks for the kind wishes!
Phil
East Yorkshire.
(You never have to ask a man if he is from Yorkshire, if he is, he will have already told you!)

[hermetic]

My week this week, got a couple of useful days in, and some part days, built up the new flue, but will be fitting it next week weather permitting, tried out a bit of TIG cam, but I need to cover the back of the mask to prevent reflections, so will do some more soon. You really will learn absolutley nothing from my TIG "skills" save to say that I can make a fair job of steel, but find aluminium much harder, which, by all acounts, it is! Thanks for watching and subscribing, leave comments and any questions you may have (why are you such a T*aT) is not a valid question, and anyway, I don't know the answer!
Enjoy, subscribe, laugh!

Phil

https://www.youtube.com/watch?v=qAtN_7ZAlH0&

https://www.youtube.com/channel/UCKf...XltBjj7MWtdjWA