Author Topic: Trying to Quieten the 110KVA Generator  (Read 4809 times)

Offline awemawson

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Trying to Quieten the 110KVA Generator
« on: August 20, 2020, 10:19:44 AM »
Life is a bit challenging at the moment, being lived in one hour bursts, with the wife and myself doing shifts one hour on one hour off looking after new puppy so that severely limits what I can achieve or get committed to.
 
But I decided to tackle the noise from the generator. It sits in a semi open stable that is clad in 'Yorkshire Boarding' - that is 6" wide boards mounted with 1" gaps between them. My main issue is not causing a nuisance to our guests in the holiday cottages.

Using a sound 'app' on my 'phone I'm measuring 107 dBA adjacent to it, and 65 dBA in the court yard garden surrounding the cottages.

I'm using a two prong approach. Build a 6 metre long sound deadening wall parallel to the generator, with a flanking wall at 90 degrees to partially close off the entrance, and I'm going to direct the exhaust vertically, and thanks to Pete who got me some lengths of suitable pipe the exhaust modification is underway.

Yesterday I set a length of the pipe in the lathe ready to thread it 2.5" BSP but something was very odd about the steady rest - it wasn't running right. Eventually I found that one of the bearings that form the tips of the fingers had collapsed.

Very fortunately my box of odd squirrelled away bearings provided an exact match so I was able to turn the end down to 2.960" being the major diameter of 2.5" BSP, but then my time ran out!

This morning I was able to do the actual threading, and also a 'rain cap' for the vertical exhaust was delivered so things in that area are progressing in fits and starts.

I won a pile of 15 industrial partition sheets (Facebook Marketplace) that will provide sufficient material for the walls - these were delivered Monday but I've not been able to start on them. They are a 70 mm thick sandwich of steel facing and insulating foam core. I will fix a 6 metre length of 80 x 80 x 6 mm angle iron to the frame of the stable at roof height, and to the concrete floor below, and use self drilling sheeting screws to fix them (as I have a few hundred left over from another project)

FH Brundles delivered the angle iron this morning and I managed to give them a coat of Red Oxide primer (as rain is threatened) - there should have been three but one was bent like a banana and I rejected it - replacement due in the next day of two.
Andrew Mawson
East Sussex

Offline Brass_Machine

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Re: Trying to Quieten the 110KVA Generator
« Reply #1 on: August 20, 2020, 10:52:06 AM »
Looks like you are off to a good start.

How often does the generator run?
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Offline awemawson

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Re: Trying to Quieten the 110KVA Generator
« Reply #2 on: August 20, 2020, 11:01:42 AM »
Eric, VERY rarely as I'm inhibited by the noise ! This is what powers my induction furnace.

A few pictures omitted off last post due to rushing:

The existing 'collar' that terminated the exhaust currently is going to be a b***r to remove - I know as I tried before I installed it.
Andrew Mawson
East Sussex

Offline Brass_Machine

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Re: Trying to Quieten the 110KVA Generator
« Reply #3 on: August 20, 2020, 11:38:33 AM »
Sounds like a good plan.  <-- See what I did there?  :doh:


I need to build an enclosure for the CNC router and the shop vac. Both are very loud when running...
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Offline vintageandclassicrepairs

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Re: Trying to Quieten the 110KVA Generator
« Reply #4 on: August 20, 2020, 07:04:50 PM »
Hi Andrew,
I have fitted some "flue" silencers that proved quite effective quietening noisy oil fired boiler installations
If they have stainless stacks the pipes can amplify the noise alarmingly
Of course most modern units are now condensing low level outlets
A coarse stainless steel mesh is formed into a tube shape about 3 ft long and a couple of inches smaller than the flue, this is wrapped tightly with ceramic insulation blanket and bound with stainless binding wire, then a wrap of lagger's foil tape. This is fed down the SS flue and reduces the noise noticeably, extra units can also be added to
reduce the noise even more
Same principal silencers(?) are used on competition motorcycles and cars

John

Offline awemawson

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Re: Trying to Quieten the 110KVA Generator
« Reply #5 on: August 21, 2020, 03:12:17 AM »
John I made one of similar construction for a little 2.2 kVA generator that I've had for years - not stainless but mild steel but it's still going strong.

I've been cogitating how to cut this sandwich panel - the core is no problem but what about the steel outer layers :scratch: Then I remembered how, using my welding bench to support a sheet of plywood for cutting, I'd cut a slit in the 3/4" steel accidentally with my old Hitachi Skill Saw.

So this morning I did a quick trial cut and it's definitely the way to go  :thumbup: The blade is already old with at least one chipped tungsten carbide tip so if it has eventually to be replaced it's due anyway.
Andrew Mawson
East Sussex

Offline awemawson

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Re: Trying to Quieten the 110KVA Generator
« Reply #6 on: August 21, 2020, 06:43:33 AM »
So in another of my permitted one hour bursts of activity I've pretty well 'cleared the decks' in the Stable to prepare for wall building - just a couple of feed bins to move but they can be shunted about in the stable as work progresses.

The rest has found a temporary home in the tractor shed despite NOT being tractors!

Thank goodness for Pallets and Forklift Trucks  :clap:
Andrew Mawson
East Sussex

Offline awemawson

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Re: Trying to Quieten the 110KVA Generator
« Reply #7 on: August 23, 2020, 01:20:35 PM »
Not much done due to puppy syndrome, BUT a major achievement was getting the upper angle iron in place.

Six meters long and weighing 75 kgs I dragged it out with the fork lift at the beginning of one of my 60 minutes sessions. Couldn’t lift it into place as the mast of the forklift would need to go 3 foot through the roof ! I was scratching my head how to build a frame onto the forks when one of our cottage guests happened by to see what I was up to. In no time at all he had volunteered, and as a two man lift it was relatively easy to rest one end on the first RSJ then walk the other up a ladder and slide it into place. The rest of the wall should be easy now that first angle is in place
Andrew Mawson
East Sussex

Offline djc

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Re: Trying to Quieten the 110KVA Generator
« Reply #8 on: August 23, 2020, 03:26:47 PM »
Classic way to lift stuff with a forklift near to the roof is as:

https://fleggprojects.co.uk/wp-content/uploads/deliver-install-link.jpg

These are also good: http://www.sumner.com/sumner/sub/productb/main.21.7.8.21.0.0.html

Can do similar on a Genie lift by turning the forks upside down.

Anyway, on the sandwich panel cutting, be careful it does not close up on you at the end of the cut and pinch the blade. I cut the same style of insulated panels for walk-in cold rooms (craftsmen of wood, look away now - I use a Festool TS55) and even when fully supported on a sheet of ply, within about 3 inches of the end, it will grab. When I get near the end of the cut, I lift the panel and put an offcut of ply directly under the cut, so the outer edges of the sheet are in mid-air. Then the self-weight of the panel makes the cut open up.

Offline awemawson

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Re: Trying to Quieten the 110KVA Generator
« Reply #9 on: August 23, 2020, 03:33:28 PM »
Good point about the panels closing up, I had a 9" angle grinder pinch when cutting channel section that resulted in me seeing bare leg bone  :bugeye: Fortunately my son was there to cut the power as the grinder flew through the air. He was about 12 then and is now 40 but I still have the angle grinder  and the scar!

A chap who rents one of my containers has a Genie Lift in it, but is rarely here to scrounge from!
Andrew Mawson
East Sussex

Offline awemawson

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Re: Trying to Quieten the 110KVA Generator
« Reply #10 on: August 24, 2020, 06:51:07 AM »
This is progressing in tiny little steps for the reason already mentioned but I did manage to move the upper angle and re-fix it, and bolt down the lower angle directly below it set by plumb-bob.

I decided to move the upper angle (and hence whole wall) nearer the generator for two reasons - firstly the wider gang way inside was a waste of space, and secondly the space from the outer face of the insulated panels to the next timber beam would have been insufficient to get my drill in with a long series drill on it.

Lower angle bolted down with 'Thunder Bolts' which are excellent when they work - I did manage to shear some off when building the Pig Palaces !

- next step measure and cut some panels, but not until the long series drills arrive.


Andrew Mawson
East Sussex

Offline awemawson

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Re: Trying to Quieten the 110KVA Generator
« Reply #11 on: August 25, 2020, 01:15:59 PM »
What with Puppy, a visit from three grand children all under eight, and a simultaneous visit from a friend with two under two year olds not much got done

BUT the replacement steel angle iron got delivered in the pouring rain, and set in the hopefully dry stable for a few hours 'angle up' to dry, and I've just wiped it down with white spirit and roller coated it in Red Oxide in the 25 minutes I've been allowed  :bugeye:

This angle will be cut to form the top and bottom braces of the second wall in the position shown in the picture

Andrew Mawson
East Sussex

Offline chipenter

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Re: Trying to Quieten the 110KVA Generator
« Reply #12 on: August 25, 2020, 02:45:19 PM »
I agree about the thunder bolts the trick is not to use a worn drill bit , this can get expensive  with the torx heads .
Jeff

Offline awemawson

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Re: Trying to Quieten the 110KVA Generator
« Reply #13 on: August 26, 2020, 07:50:09 AM »
4 mm long series drills arrived so time to do a test fit.

Big failure  :bang:

Much to my amazement 4 mm is not large enough as a pilot despite these screws being self drilling. The plastic 'star head' spins on the screw meaning I could only remove it by squashing in the vice - lucky it's not on a full size panel !

Drilling to 5 mm from the rear showed that is big enough - so it should be the screws are only 5.5 mm ! One successful fixing and 5 mm long seriies added to the buying list - oddly 1/3 rd the price of the 4 mm - more common I suppose ?

The screws are 50 mm too long, but being hardened snap off cleanly with a tap of the hammer :thumbup:
Andrew Mawson
East Sussex

Offline awemawson

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Re: Trying to Quieten the 110KVA Generator
« Reply #14 on: August 26, 2020, 10:50:12 AM »
This is turning into one of those 'why did I ever start' jobs :bugeye:

I thought I'd cut one panel to size, offer it up and clamp it in place to mark out cut outs for it to tessellate with various bits of the stable structure .

First problem: cutting with the circular saw the lower cladding tends to sag away and not be cut, and as the off cut falls away the cladding de-laminates. Also lost more teeth from the saw. Finished the cuts with a 9" angle grinder that only just cuts deeply enough - be ok laying flat on a sacrificial board maybe

Second problem: the tressels that I set up keep collapsing - not really man enough for the job

Third problem: Having cut the sheet nicely to size with a 1/2" wiggle room I can't get it in place due to angles, beams etc and had to cut a further 1 - 1/2" off to get it in.

Going to have to cogitate before cutting any more. I do have spares but it would be nice not to waste them

Anyway, it's roughly in place and held with clamps - if I decide to use it I will raise the base the 1 - 1/2" rather than leave a top gap


Andrew Mawson
East Sussex

Offline Spurry

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Re: Trying to Quieten the 110KVA Generator
« Reply #15 on: August 26, 2020, 01:57:50 PM »
That's looks like the foam gun could make a very useful contribution to that top gap.

Offline awemawson

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Re: Trying to Quieten the 110KVA Generator
« Reply #16 on: August 26, 2020, 02:34:42 PM »
Yes it's difficult to decide how fussy to be. There is a (needed) 2" gap from partition top to corrugations otherwise getting them in is practically impossible single handed.

There are foam 'eaves fillers' available that fill the corrugations but still leave the 2" gap. I was on the point of pressing 'buy it now' earlier but decided to wait and see what the effect is without them - if I do fit them I can fit a bit of 2x2 to the top with the eaves filler glued to it. Ideally I'd lift the panel to the corrugations to loose the gap and keep the foam out of any ground dampness but that may not be possible.

If I get the chance tomorrow I'll cut a second panel to the 1/2" wiggle room and try another approach angle - the trouble is that both the floor and the roof slope, and what 'should fit' below the angle iron doesn't clear the rest of the roof.

(I need to bring the panel in horizontal (due to height of entrance) turn it 90 degrees, advance in to the point it's going, then incline it at 45 degrees up slope towards the generator, and tilt it up until it engages with the top angle making the angle steeper as I go until vertical by which time it should be in place. Trouble is I can't lift it easily and have to have it on my back Ninja style!)

Andrew Mawson
East Sussex

Offline vtsteam

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Re: Trying to Quieten the 110KVA Generator
« Reply #17 on: August 26, 2020, 10:24:53 PM »
Andrew I have a distant memory of some articles about silencing 4 cycle motors with tuned pipe lengths (straight, not automotive header/collector pipes) And increasing exhaust extraction efficiency at the same time. It's a really dim recollection, but I think it was actually in experimental aircraft design.

Pipes were quite long, related to RPM and wavelength of exhaust gas, and it gave calculations. Extremely simple and low cost exhaust systems. Since your generator runs no doubt at fixed RPM, a simple straight tuned pipe might be doable, especially if vertical. Wish I could remember where I saw that -- about 25 years ago. Maybe an older EAA publication which I collected. If I get a chance (and if of interest to you) I'll take a look at my old EAA books.
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Offline awemawson

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Re: Trying to Quieten the 110KVA Generator
« Reply #18 on: August 27, 2020, 07:00:28 AM »
I gave up with the circular saw and reverted to the 9" angle grinder - oh that it was 10" as it only just cuts deeply enough if it is held at precisely the right angle. I cut the next panel (panel #2) with just the 1/2" wiggle room and it went in very nicely, doing a dance I described in my previous post.

By counter weighting cut panels I was able to move them on the pallet truck which made things much easier.

Panel #3 cut to the same loose fit wasn't loose enough and had to have another inch removed. I still haven't cut the first panel round the beams as I ran out of allotted time.

By the way, no there won't be big gaps between panels - they are just clamped roughly in place, and when I can screw them will be shunted along to fit tightly - probably have to pull them together with a strap.
Andrew Mawson
East Sussex

Offline awemawson

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Re: Trying to Quieten the 110KVA Generator
« Reply #19 on: August 27, 2020, 10:08:38 AM »
So in anticipation of a friend probably coming round this afternoon I have raised panel #1 about 1 1/2" to close the top gap and marked up for cutting setting in relief for the three structural members that need insetting.

Double manned it will be easy to set it on tressels and cut the bits out and put it in it's final position, - probably only take 20 minutes, but single handed would be quite different.

Poor chap will be press ganged if he turns up !
Andrew Mawson
East Sussex

Offline awemawson

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Re: Trying to Quieten the 110KVA Generator
« Reply #20 on: August 27, 2020, 02:55:34 PM »
Well my friend did indeed arrive and taking the panel down, cutting the reliefs, and putting it back, as expected was a very quick job - it's now in place to receive the screws just as soon as the 5 mm long series drills turn up.

I've deliberately cut the slots on the large side and the gaps will be filled with expanding foam. I thought it useful to have something that the foam DOESN'T stick to to use less foam and leave a fairer face so I posed the question to Google:

"what doesn't expanding foam stick to?"

And it seems that I asked the same question in 2005 - the answer being 'waxed paper' but the thread I found on RCGroups, which sweeps up threads from Newsgroups was rather sobering as no fewer than four of the contributors to the thread are no longer with us  :bugeye:

Thread here:

https://www.rcgroups.com/forums/showthread.php?341842-What-DOESN-T-expanding-foam-stick-to
Andrew Mawson
East Sussex

Offline awemawson

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Re: Trying to Quieten the 110KVA Generator
« Reply #21 on: August 29, 2020, 09:27:17 AM »
A progress report:

I have five panels now in place, four of which are pretty well fixed, the fifth being held by clamps. I tried pulling the second panel into the first using a ratchet strap but frankly it was no better than thumping it with a baulk of timber and a big hammer so I gave that idea up!

I'm again limited by shortage of long series drills - it's taken 10 to get so far  :bugeye: Now admittedly two were my fault, one I dropped the drill, and two I trod on the drill, but the other 8 were in use breakages - mainly on the angle on the floor - there are distinct hard spots in it so goodness knows what went into the pot when it was rolled. Now at 135 mm long they are long wobbly drills, and mostly unsupported as it passes through the insulation but it starts penetrating the angle and suddenly grabs, and it's not just before breakthrough it's in the middle of the web.

Today I took delivery of a pack of 'eaves fillers' and a pack of expanding foam cartridges and a gun to apply them.

. . . more drills on order !!!!!!

Andrew Mawson
East Sussex

Offline awemawson

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Re: Trying to Quieten the 110KVA Generator
« Reply #22 on: August 29, 2020, 11:39:54 AM »
I opened up the pack of 'Eaves Filler' and did a trial fit.

I think that it will be OK but may need a bit of squirty foam behind it to secure it in place/
Andrew Mawson
East Sussex

Offline awemawson

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Re: Trying to Quieten the 110KVA Generator
« Reply #23 on: August 30, 2020, 11:54:35 AM »
No wonder I couldn't unscrew the collar on the end of the exhaust pipe - the thread has been WELDED  :bang:

Probably have to cut it off somehow, but I still want a bit of thread for the elbow to screw onto  :scratch:

(Pipe extends as far as the chalk mark inside the collar)
Andrew Mawson
East Sussex

Online russ57

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Re: Trying to Quieten the 110KVA Generator
« Reply #24 on: August 31, 2020, 03:26:36 AM »
Just hi temp loctite...


Maybe you can just grind the beads off and leave the bulk of the pipe?

-russ