Distance from peripherals (P10, N2, chiller, UPS, etc) to EPMA?

[lnharrison]

Hello All,

We are up to our eyeballs in finishing the last details with an EPMA lab renovation at CSU. Exciting! In finishing the last details of where to place instrument peripherals (chiller lines, P10 and N2 gas canisters and lines) in the side room relative to the EPMA, I realized there is no guidance in the JEOL room spec document on whether or not there is a limit of the distance from the EPMA to the peripherals (for ICP-MS for example, chillers have to be within 3 m). Does anyone know if there is a limit to how far a chiller, the gas canisters and pumps can be placed from the EPMA? Also, the peripheral room with a chiller has no floor drain and we wondered if anyone had experienced or heard of installing chillers within secondary containment in the event of a failure or leak?

I'm attaching our preliminary design plan to illustrate some of the questions above--big thank you to Dawn Ruth for the examples from her lab! Any input is greatly appreciated!

Lauren

[Probeman]

Hello All,

We are up to our eyeballs in finishing the last details with an EPMA lab renovation at CSU. Exciting! In finishing the last details of where to place instrument peripherals (chiller lines, P10 and N2 gas canisters and lines) in the side room relative to the EPMA, I realized there is no guidance in the JEOL room spec document on whether or not there is a limit of the distance from the EPMA to the peripherals (for ICP-MS for example, chillers have to be within 3 m). Does anyone know if there is a limit to how far a chiller, the gas canisters and pumps can be placed from the EPMA? Also, the peripheral room with a chiller has no floor drain and we wondered if anyone had experienced or heard of installing chillers within secondary containment in the event of a failure or leak?

I'm attaching our preliminary design plan to illustrate some of the questions above--big thank you to Dawn Ruth for the examples from her lab! Any input is greatly appreciated!

Lauren

That looks like a great design.

I couldn't tell from the drawing but are the roughing and backing pumps also in the small room with the chiller and gas cylinders?

We used a "pass-thru" (hole in the wall) with some special sound deadening material for all the peripherals:

https://smf.probesoftware.com/index.php?topic=830.msg5230#msg5230

My only other suggestion would be to replace the N2 gas cylinders with a N2 generator.  Ours supplies the entire CAMCOR facility so is larger than what you would need for the one instrument:

https://smf.probesoftware.com/index.php?topic=1228.msg8554#msg8554

As for your question about distances, I would say the only line lengths that might be a concern are for the backing pump on your turbo or diffusion pump, since that will be operating in the non-laminar flow regime.  The roughing pump will mostly be operating in the laminar flow regime so length should not be as much a concern.

On the chiller lines the length shouldn't be an issue but be sure to use opaque coolant lines (non clear) to prevent light from getting in.  This will prevent algae from growing in the chiller. We found that using black rubber lines and RO water we never need to worry about any additives nor cleaning except maybe once every 5 years or so for a regular maintenance.

[sem-geologist]

While I am in charge of Cameca probes and have bad and good experience with SEM and peripherals, please bear in mind that I have no experience with JEOL, but some of my below blabbering could be applicable.

Indeed, placement of these (and other) peripherals is crucial, and it should be the main point in lab design, not the last "cherry on the cake" kind of approach. We are currently ongoing with planning new place to move two of our probes to, thus I am kind fresh on reviewing all past mistakes of our present laboratories.
1) Room for peripherals and main room for EPMA has different requirements: in EPMA main room you want stable as possible temperature and humidity. In peripheral room you want reliable and efficient cooling (normally don't care about stability and humidity, but rather cooling solution which would survive partial failure, i.e. double AC system where if one fails, other overtake)... unless you want to put P10 gas there (which I think is bad decision). If you place P10 in peripheral room, then Air conditioning needs to be in peripheral room same stable as in EPMA room, and temperature differences between those two rooms stable as possible. Humidity control then for peripheral room is also important - that will increase complexity and costs.
2) peripheral room is for two reasons: put there devices which produce a lot of heat, and are loud. It is to take heat and noise source out of the main EPMA room. N2 gas and P10 gas bottles do not produce heat and noise and it is a mistake to be placed away from probe into peripheral room with devices which produce heat and noise.


I have a real life story about some SEM facility and how cardinal design mistakes lead to situation just a minute from exploding such lab!
   About ten years ago a nano-functional material lab was made in our building with two main rooms for Zeiss FE SEMs with single small peripheral room between them. In the peripheral room there was placed beefy UPS (20KVA), two chillers, two air compressors (does not you JEOL need one?), two primary pumps, network gear, place for liquid nitrogen dewar (as one of SEM has Cryo capabilities) and... all N2 bottles (at time of near accident there was only two of them). And for all that small critical room - only a single air conditioning system installed! Installed AC is far from fail-proof (the outer unit of AC split system is installed in completely nonsensical place restricting air exchange and restricting maintenance cleaning).
   One hot summer, during season when most of people are on holidays, air conditioning in that peripheral room had failed. It is hard to point exact day, but first signs read from logs that something is wrong is from Friday evening after working hours, where one of SEM stopped its turbo pumps as cooled water flow from chiller went below the water pressure threshold. Logically reconstruction the events shows that most probably AC failure was followed with failure of air compressor. Failure of compressor was loosing the pressure and compressor heat disipation is designed to work in continuous mode. So compressor could not switch off and heated up to 120C. As chillers was very close to the air compressor, water in them had evaporated and both SEMs went down...
    When I got at Monday near lab, I hear many beep noises which were incoming from thermal warnings of UPS and network gear and chillers (no water beep). As I got into lab and went straight to the peripheral room - opening the door to that room can be directly compared to opening door of oven - the heat wave hit my face. Remember gas bottles? I had one of dreadest sights in my life: by walls near chillers the N2 bottles were situated – The rust ( normally present at sides of seasoned gas bottles near bottom) all that rust had detached and was around bottles on the ground as bottles itself were clearly on thermal strain. Had I not been there in time it sure would had blown. UPS batteries basically went worthless and needed replacement. We made then big huge sign on the door: "In any case - do not close!" so that situation would not repeat itself. However design of peripheral room, too small room, leaves no place for additional AC there.

Another nuisance wiht N2 gas is that those Zeiss SEM does not cut the gas inlet when chamber gets vented. I found so annoying to have to go back and forth between rooms when wanting to stop gas venting that I would not agree installing even just N2 gas away from any probe or SEM ever again. Also having bottle monometer just in sight makes it clear how much gas is left and makes it less often to occur: "ups there is no gas".

So:
1) technical gas bottles should not be placed in rooms where heat sources are
2) peripheral room needs well thought efficient ant reliable air conditioning (in particular if UPS will be there). UPS batteries if overheated could also start a fire!

Peripheral room should be from side where vacuum pipes from pump will have shortest path to probe, the less distance the less power wasted for pumping (in our case upgrading and significantly shorting primary vacuum line we save 3.5A per hour!)

[sem-geologist]

BTW, Initially I had not seen the attachment.

Why your dry-scroll pumps have oil filters mounted at outlet?
I am also a bit confused. I see 2 powerful Edwards dry scroll pumps (15i) - but room is only for single probe... second pump is for carbon coater?

I would not install UPS under table - it is crucial to not restrict UPS ventilation else battery life will shorten significantly.

Also In any case no Cu tubing for P10 gas, unless you want seasonal weather integrated in the measurements. Only polyamid pipes all the way. Copper is excellent heat conductor thus would equalize gas temperature to temperature of the wall.

I also am a bit intrigued by chiller leak prevention. I have experience of some dutch mark chiller leaks - nothing spectacular. It had leaked few drops  - but far away from something severe. As for probes where I have more experience, two Labtech italian chillers had leaked a bit - but that was after neglecting signs it should be inspected (failure of pump). None of our chillers (in SEM and EPMA lab) has floor drain in the peripheral rooms, and its lack never caused any problem. I find those Labtech chillers nice as most of system can be repaired by myself - and thus I would never place chiller into some container as A) it will block heat exchange B) will restrict access to inspect or maintain/repair chiller.