Can I blow up the Compressor Resevoir?

[ImanCarrot]

heh! like the Signature

Good idea on the taking air from inside the lab and sticking it into the intake of the compressor.

[jphagen]

Cold outside air will contain less moisture per volume then warm inside air at the same
relative humidity. When it is warmed up the relative humidity goes down, ie.
drier air.
What I think you need if the tank is outside or colder than the usage point, is
to heat the tank to about 40F, this will allow the tank to act as a air drier and
allow you to drain the tank. The air drier should be after the tank for the final
moisture removal. During warmer weather it will operate the same way but the air drier will, do most of the final moisture removal.
A air drier should be after the storage tank in all cases, otherwise it uses most of its energy cooling the hot air and not generating a dew point condition, use the tank or storage for the initial cooling, then the drier for the moisture removal.

[Fred968]

I have one question. Is the plastic pipe rated for compressed gases? Isn't there some OSHA rules for temperature and pressure? Cold temperature would make the pipe more brittle.

[sendkeys]

*edited* To slow my,idea was already given hehe *edited*

[Geof]

Originally Posted by ImanCarrot Quite a few good ideas there, many thanks! The pipes are 1.5" dia plastic and go stright from the compressor up to the ceiling level. They then enter the building and go across the roof to my lab. I'm gonna see if the boss will fork out for a new air "dryer" with temperature control although I can hear the answer already hehe

I am amazed that you have got away with plastic pipe for compressed air especially knowing how picky the safety laws are in the UK. You literally have a 1.5" diameter bomb running across the building.

This is something that should be corrected if you want to remove the possibility of having chunks of plastic shrapnel whistling past your ears at around the speed of sound.

But to get to your main query; what I get out of reading it is that your problems arise from varying air temperatures not cold air per se. When your machine is not operating the air in the pipe inside the building equilibrates to room temperature but when the machine is running the air does not spend enough time in the pipe to come up to room temperature. You start the machine and initially it is running on room temperature air but then after a short while it gets hit with cold air. The temperature transition is probably abrupt so the machine is differentially cooled which can be expected to cause all manner of problems in maintaining precision.

My suggestions is to fix two problems with one solution. The plastic pipe must be replaced; your personal safety requires that even if it was not illegal, which I am sure it is. Replace the plastic with something like 1.5" schedule 20 galvanized pipe and replace the straight pipe run with a labyrinth long enough to be confident the air spends enough time in the pipe inside the building to equilibrate to the building temperature when the machine is operating. You may have to find someone to do a calculation for heat flow across the pipe wall to get an estimate of the wall area needed and may find it is more efficient to run four 0.75" schedule 5 in parallel between two manifolds. This gives you the same interior cross section for the compressed air flow but twice the wall area of thinner material so the heat flow is better.

[ImanCarrot]

Jesus! you got me scared now so I went and checked the Air Pipes! they are NOT plastic as I first thought *phew*- they are like blue plastic coated Aluminium (Aluminum for my friends in the States - it says the following on them: "Transair Tube Aluminium 37 X 40 calibre. PMax 37 Bar. SI 118738/003" Whatever on earth that means hehe *checks Bar to PSi*- 37 Bar= 537 PSI which is cool 'cos I'm only at 120 PSI. But, at least it's not plastic I got 6 pipes going overhead to supply my main machine and a second machine and air hoses and was scared sh*tless then!

I think I may propose the idea to my boss that I only work in the summer so that the air intake is warm enough... what do you reckon the odds are on the idea being accepted? lol

When your machine is not operating the air in the pipe inside the building equilibrates to room temperature but when the machine is running the air does not spend enough time in the pipe to come up to room temperature. You start the machine and initially it is running on room temperature air but then after a short while it gets hit with cold air. The temperature transition is probably abrupt so the machine is differentially cooled which can be expected to cause all manner of problems in maintaining precision.

Totally correct I try and minimise the effect by programming the machine to do a Warm- Up Cycle an hour before I come in in the morning and programme it to do an idle cycle between one copmponent and the next so it's never allowed to cool down... 'tis a stressful job but that's why I get paid hehe

[EDIT]In fact! I may propose that my boss moves me and the machine to the Bahamas lol... we can all wish hehe![/EDIT]

[Geof]

Originally Posted by ImanCarrot Jesus! you got me scared now so I went and checked the Air Pipes! they are NOT plastic as I first thought *phew*-

Scared is good! Scared probably lives longer than not scared.

Bahamas idea probably no good; simply invert problem. Move machine and operator to join compressor outside then all experience same temperature.

[ImanCarrot]

eeek! noooo! Manchester in winter is blinking freezing lol.

Problem has been almost solved- the machine that I check what I'm making on (called a Form Talysurf) was playing up- got the company that makes it to send in an engineer to service it- he says the optics were dirty which was dropping the laser intensity and that there's no way I would get good measurements at 16 degrees celcius, which is what my lab was at last week.

Got some more heaters and got lab almost up to 20 degrees- not quite the Bahamas but getting comfortable- not that I'm bothered by the cold (I'm Scottish), but the machines abviously feel the cold, poor things! *buys a fleecy jacket for the machine* hehe

Presumably if the Talysurf doesn't operate correctly at 16 degrees celcius, then my diamond turning lathe wouldn't either I was fighting against too many variables and didn't really have a chance!