-- Steve Philson philson_at_nmr.chem.umn.edu Director NMR Lab 612-626-0297 Chemistry Dept. University of Minnesota -------------------------------------- > From: Chris Rithner <cdr_at_chem.colostate.edu> > Subject: Re: > Content-Type: text/plain; charset="us-ascii" ; format="flowed" Hi Charlie, I've successfully moved three magnets at field using a home built cart with pneumatic tires. I sweat bullets through the whole process; we had to make four 90 degree turns through narrow passageways, several steel framed doorwarys, negotiate several ledges, ridges, and bumps, through a distance of about 50 meters on a single floor (no elevators involved). The magnets survived with no unusual behaviors other than an elevated He boiloff for about thirty minutes following the adventure (due, I presume, to sloshing of the He). The magnets we moved were narrow bores: an Oxford 300 built for the Bruker AC series (late 80's, short, fat, stubby, tall stacks), an Oxford 200 (vintage late 70's, tall, skinny, short stacks) and an Oxford 270 (early 80's, same sort of design as the 200)...the 200 and 270 were on IBM-WP series spectrometers from that time period. If memory serves me, the 300 has an exposed solenoid through part of its Helium cycle and the 200 and 270 are always fully immersed. We did a Helium fill within a week of the move, we did *not* do an N2 fill for the reasons you mentioned. There were several points during the move when the 300 magnet (the most sensitive and valuable in my estimation) was tilted significantly (5 degrees) from the perpendicular and once when it grabbed a metal door from its stop and made a valiant effort to hug it...one of us jumped at the door, smacked the magnet in the process, but prevented contact. The "cart" we used was assembled under the magnet stands as follows. The magnet rested directly on the axles. The magnet was "jacked" up gently with three Johnson bars and a fourth person shoved wood block underneath the stand to get the necessary clearance. The fully deflated pneumatic tires were assembled on the axle and then evenly pumped up to raise the magnet off the wood blocks. It rolled smoothly over every obstacle including a one inch jamb. Our biggest problem was turns since we had no mechanism for really steering other than cocking the axles left or right. More than once we used two Johnson bars to ease things around in place; once the Johnson bar slipped from one side and that led to the "5 degree" tilt (it seemed like about 45 at the time). Your arrangement should work nicely. Varian uses an Al tripod with a stainless jack of the sort used to handle rigging on sail boats (Mark Stevenson, the magnet guru, is a sailor!). Good luck. cdr ***************************** Christopher D. Rithner Director, Central Instrument Facility Research Associate Professor Chemistry Department Colorado State University Ft. Collins, CO 80523 970-491-6475 (or x1801 for fax) cdr_at_chem.colostate.edu http://www.chm.colostate.edu ------------------------------------- > From: Jerry Hirschinger <hirsch_at_purdue.edu> Hi Charlie, You might save $10K and you might lose the magnet! Which can you better afford? The supports within the magnet assembly are very fragile and stress can break the vacuum seal, especially if the seals are old. O-rings deteriorate with time and you should consider doing a seal replacement if the seals are near 10 years old. You need to be concerned with what magnetic fixtures are near the magnet during the move and how hard will they pull the magnet sideways within the can. For instance, if you go through a steel door frame, go through it centered. I definitely would NOT use an engine hoist on an energised magnet because it's a very big chunk of steel that will be on only one side of the magnet. If you do use it, bring it to the magnet slowly and away slowly. Extend the arm of the hoist so the main mass of it is outside the 5 Gauss line, if possible. To do this you might need volunteers to stand on the counterweight. Better to use an overhead hoist. Beforehand, we install on the ceiling an eyelet rated to lift the magnet, if possible. The ramp should be OK as long as you go up it steadily without jerking. The main thing is if you have to make side stresses, then do it slowly. Do all movements slow and steady. Your ideas about the Cryogens are good - Helium high and Nitrogen low. If you can, it is better to de-energise the magnet and move it cold. This removes all worries about steel and iron so you are only left with worries about tilt and jerks. In any case, I would remove the dogbone and seal the ports with one layer aluminum foil with a pinhole in the foil. This gives an easy bursting disk type of escape route for the gas in case of a quench or vacuum loss. Keep good ventilation in the rooms for the same reason. Removing the dogbone may also give you better door-height clearance, allowing larger dolly wheels. Also, have a towel handy to wipe up the sweat!! Good luck, Jerry At 02:04 PM 6/22/00 -0400, you wrote: >Dear AMMRL Bank of Experience: >As I am pressed to move a 4.7T Oxford and it has limited but finite >usefulness I want to do this economically. My sense is that energized >I know it's risky but I'd like to save $10K. >I will post summary to archives. >Charlie Dickinson ===+++=== Jerry Hirschinger; NMR Instrumentation Engineer Purdue University Chem-MCMP NMR Facility 1393 Wetherill Labs, rm. 365A West Lafayette, IN 47907-1393 Phone: (765) 494-5288 FAX: (765) 494-0239 email: hirsch_at_purdue.edu ---------------------------------------- > From: "Joe L Schwartz" <jschwartz_at_Nalco.Com> > To: charlie (leonard charles dickinson) Hi Charlie. When I was at the U of Wisconsin, we moved one of Craig Bradley's magnets (Cryomagnet Systems) while it was at field. We originally had this at 4.7 T but later ramped it to 295 MHz 1H. If I recall correctly, we moved this magnet when it was at 295 MHz. Nonetheless, the field was at least 4.7 T. We moved it with a steel hoist (or engine stand) and steel chains as we did not have any nonmagnetic equivalents. In our case, we only had to move it across a room, maybe about 20 or 30 feet. We just moved it with the hoist, making sure that it did not swing wildly in the process. We moved the hoist in slowly with chains hanging from the hook on the end. The chains became rather straight when they were hung above the magnet due to the magnetic field and this was the most noticeable interaction with the field. We hooked them to the top of the dewar - the magnet was similar to an Oxford magnet. Be aware that the strongest field (outside of the dewar) is at the bottom of the magnet as the coil is normally near the bottom of the dewar. Then we lifted the magnet off the floor and three or four of us began to slowly move the whole assembly across the room. We made sure that the magnet did not swing into the steel motor stand. We had no problems. I read that you were going to move your magnet through a doorway. I would be cautious if the doorway has a steel frame. I don't think the incline is too big of a deal - just be sure to keep the magnet from tipping. As long as you try to move the magnet smoothly, I don't think you'll have any problems. Also, the smaller magnets can be rather top-heavy when they are on their legs so you will probably want to have one or two people stablilize the magnet while one moves the cart, just to be sure the magnet doesn't tip over. I don't recall if we had our magnet topped off with helium when we moved it. It probably would be a good idea to have it topped off. I don't think the nitrogen level matters much. In fact, it's just excess weight for the move. Most of what I have told you is common sense that you would probably know . I just thought I'd let you know of our experience and that a move is not a problem, provided that you are cautious and take your time. I hope all goes well. Regards, Joe ------------------------------------- > From: Ben Bangerter <ben.bangerter_at_yale.edu> > er-Encoding: 7bit Charlie, We successfully moved an erergized WM-250 magnet last summer. But we are pretty well set up to do this. We have a 2 ton aluminum tripod (cost:~$1500, Spanco, non-magnetic, mostly), a chain hoist (magnetic, totally), straps and rings, and we built a sturdy dolly, with 6 inch wheels (wheels alone cost $126) and a frame of 4x6 Douglas fir beams. I believe we filled with helium just before the move. It was all on one level, but over a tile floor which caused some vibration. We had no problems. We also moved a non-energized 11.7 T the same distance with this setup, and lifted an energized 11.7 T to mount TMC legs. Bruker engineers used the gear to set up two 400 MHz systems for us last year, too. I wish I had bought this stuff years ago, it would have saved us a lot of grief (we now have 13 NMR magnets in the building.) An investment of $2500-3000 for this kind of gear makes a lot of sense for a lab with magnets to move. Perhaps we could help you with this move - give me a call if you are interested in further discussions. Ben Bangerter 203-432-3942 *************----------------------- > >From jmiller_at_spartan.ac.brocku.ca Fri Jun 23 10:15:33 2000 We've moved a Bruker 200 magent -- large dewar version about 20 feet - we slipped it onto a carpet and moved it by dragging the carpet. -- Prof. Jack M. Miller, Associate Vice-President, Research and Dean of Graduate Studies, Professor of Chemistry, Brock University, St. Catharines, Ont., Canada, L2S 3A1. ------------------------------------------d > From: Bill Stevens <wstevens_at_siu.edu> > Subject: moving magnet > In-Reply-To: <200006221804.OAA01735_at_telemann.pse.umass.edu> > Mime-Version: 1.0 > Content-Type: text/plain; charset="us-ascii" At 02:04 PM 6/22/2000 -0400, you wrote: >>Better to move with high helium to assure coil coverage even with sloshing? Definitely. >>Better to move with low nitrogen to lessen the strain on the can suspension >system? I'd do full nitrogen, too. Maybe this is an irrationality left to me by my mentor Dee Huang, but I've always felt full N2 stabilized the helium can. >>How tolerant of tilt....if it has swung when picked up that means that >a few degees tilt would be OK..I'd like to know what people observed. I've seen a 9T magnet swung wildly on its anti-vibration bed. When my 11.75T anti-vib table comes up, it tilts the magnet back and forth substantially. If helium is full, should be no problem. William C. Stevens, Ph.D. Nuclear Magnetic Resonance Facility Director Southern Illinois University Carbondale, IL 62901-4405 618-453-6498 voice 618-453-6408 fax wstevens_at_siu.edu ---------------------------------------- >; Mon, 26 Jun 2000 13:42:50 -0400 (EDT) > From: pwheeler_at_isisph.com I would suggest using nylon webbing to pick it up, rather than chains. Depending on your faith in people, you might just be able to get four strong folks to lift the thing up carefully. That's what we did with our 4.7T Varian R2D2 magnet. Twice. The thing still shims to spec in <1 min, and has a hold time easily exceeding three months. Good luck, Patrick Wheeler Isis Pharmaceuticals pwheeler_at_isisph.com 2280 Faraday Avenue phone: 760 603 2409 Carlsbad, CA 92008 fax: 760 929 0036 -------------------------------------- > rtappe_at_midway.uchicago.edu Dear Charlie,<br> I have moved a 300 MHz Oxford magnet on field between tow rooms on the same floor. The system was hooked to a small movable hoisting crane. Nitrogen and He were 100%. We tried to avoid swinging and moved all heavy metal out of the way. As pickup of small magnetic metal peaces during the move cannot be absolutely avoided the magnet was wrapped with plastic foil.<br> Tilt was not a problem as moving it with the hoisting crane kept the system in vertical position even when the crane was moved along a slope.<br> The system reached specs at its new position without trouble and is now in operation for about 2 years. <br> <br> Good luck for your move.<br> <br> Regards,<br> Robert Tappe<br> <br> ------------------------------------- > federspi_at_chuma1.cas.usf.edu Dear Charlie, I do not think a 2 degree tilt will be a problem but you might consider having the back two wheels attached to a threaded rod to adjust for tilt. It should be simple to construct. Ron Federspiel Univ of So. Fla. ------------------------------------- Dear Charlie, We move MANY of these at field and most of your observations/cautions are accurate. We usually relocate at late end of nitrogen refill schedule to decrease weight in nitrogen can and fill helium to ~80%. Use webbing straps available at most hardware stores to lift magnet instead of chains. The only concern (beyond obvious tilting,) is the size & composition of door frames. Many labs have steel frames and depending on size, the fringe field can pull solenoid/helium can resulting in broken alignment struts or a quench. This also holds true for other large ferrous objects in path. Don't forget to plug bore above and below, it's amazing how small pieces get drawn in. Take your time and think things through - you'll do fine. If you do have problems, give us a call - we are very reasonable. We also rent non-magnetic tripods if you need. Good luck! Regards, Jerry Jerry Hatvany Cryomag Services, Inc. Vice President & NMR Product Manager N.J. Corp. Office Ph. 908-281-0331 919-465-9411 Ph./FAX 888-984-8781 Toll Free Pager 919-349-7898 Cellular TelephoneReceived on Mon Jul 17 2000 - 11:04:39 MST
This archive was generated by hypermail 2.4.0 : Sat Jun 03 2023 - 16:20:26 MST