Structure Vibrating Badly
1. Is the vertical supports for the coil springs located directly underneath the centre of the spring support base plates?
2. Sometimes if they are CANTILEVERED beyond the centres ...the result will in fact be structural vibration.
3. Sometimes, if the leg does not go directly straight down to the concrete floor....a bad sympathetic vibration will develop.
4. Try doing a REED METER test on the support beams to see how much vibration is being registered .
5. Sometimes if the structure is vibrating badly enough, you can NOT get a decent stroke check on the screen because the support it is on is not QUIET.
We had a screen in Asbestos mine.......with weird vibration problem and hard to identify. We went down on 4 separate trips to troubleshoot. In the end, we went down below the screen and identified a new vertical support beam that had been installed on one corner only underneath the spring support area.
The beam was a titch on the short side and was causing the erratic vibration...a shim was used to rectify this problem.
I do not know if any of above applies to your situation....but, very well could. ■
Re: Pics Of Stroke Check
aujwc
One of the reson just to touch the cards( as mentioned by George) is to see if you can get full stroke and the shape of it.
Ziggy
www.vibfem.com.au ■
Problem Solved?
Hello Aujwc"
DID you ever find the problem with the vibrating structure??? ■
Stroke Comments For Coal Screen
Was there an actual problem or just checking?
Honestly the stroke check is not perfect, but not real bad either.
The unit looks fairly balanced by those stroke checks.
Looks like .68" (11/16" long) or between 5/8" and 3/4" stroke length.
May be holding the pencil on a little HARD. Just have a nice sharp pencil, hold it as close to right angle to the sideplate as you can and just barely touch it and take immediately off to get a nice clean, thin, readable stroke check line.
If you hold on too long.....you get mutiple strokes over each other and hard to read. ■
Re: Pics Of Stroke Check
thanks George, problem is we have some remote parts of support structure vibrating quite severely (100mm/s) but main column/beam load paths are not bad (10mm/s).
if I had just touched my pencil, I believe it would leave only a short line, less than half stroke
screen is single deck and I could not see any build up
loading is somewhat one sided, although this is fairly typical for my experience
within the mounts, there are horizontal springs, although these are much smaller than the vertical springs ■
Pics of Stroke Check
Hi All
Attached are stroke check cards I took yesterday on 2 coal screens. Unfortunately only one side of each was accessible. What I found was that some corners apparently had side-to-side motion as the pencil was only touching for half the stroke, unless I pushed heavily.
Any comments?
Attachments
img-x060933-0001 (ZIP)
■