Please re-attach the design information. There are a lot of Hui names at Kefid, any relation?

From what we know so far perhaps you could insert bowed (slightly arched) supports under the wire: similar to the Hummer screen.

For longevity use fatter wire. ■

Angie,

What are the specs on the mesh? Awfully strange that this material is testing differently after so much time - was the alloy double and triple checked?

-J ■

SOME Possibilities:

1. I love this question: "has anything changed recently?" new wirecloth, bigger or smaller diameter, change from ar steel to stainless, change of suppliers??, all of these can or could cause a problem.

2. if the cloth is BREAKING = ABUSE. ABUSE from what tho?

3. improperly tensioned wirecloth by a new employee, or someone who was in a hurry or the OH....outer dimensions are slightly overwidth will cause this.

4. wirecloth MUST BE DRUMHEAD TIGHT....overtight is better than undertight always.

5. if you are contacting underside of wirecloth steel to the steel support rails due to rubber moving off them...YES..there is your abuse. it will be evident, by looking at the underside of the wirecloth and looking at the diameter of the wire surface for "SHINING"....means it was moving and rubbing and then it BROKE.

6.Sometimes it is NOT your installing problem, it very well could be a manufacturer defect. When the mfr rolls the wires thru the CRIMPER DYE, if that dye is old and worn, instead of giving a nice clean, INDENT for the CRIMP point....if dull ...it can actually shock...the wirecloth and cause a unseeable hairline crack which prestresses MR WIRECLOTH and under vibration it breaks kinda quickly. If your life is mega shortened it well could be this easily.

7. LOOSE BENT or HOOKED metal edges will cause the cloth to be loose = BROKEN WIRES. sometimes wires will PULL OUT of the hooked metal edge, causing the section width to be oversize, become loose and break wirecloth at the crimp points or the RISER points of the support rails.

8. sometimes, folks buy "cheaper" money saving SUPPORT RAIL RUBBERS...did you know there is an actual spec for those too? FOR SURE. if they are not the correct height, thickness, and clamp on pressure to MR TENSION RAIL........they chip off, fall off, slip off, break off or some other OFF thing......and expose steel to steel and BREAKage occurs from ABUSE.

9. Sometimes folks actually make their own steel support rails...if heights are not dead on mfr spec = gap under wirecloth on underside = BREAKage from ABUSE.

10. Sometimes folks fabricate their own TENSION RAILS to pull the wirecloth tight. no problem, but typically their are made slightly wrong. The bend angles on those little pieces of steel MUST BE CORRECT, so if you copy them, you must do it absolutely right or your bent end going into the metal edge on the wirecloth MAY ride into the rail HIGHT..at that point you tension as normal, MR WIRECLCOTH starts to ARCH UP, Off the rails, vs being tensioned down onto the deck, this causes the wirecloth to have a slight space between the underside of the wirecloth and the top of the rubber. NOW MR RUBBER can move and slip off and that causes BREAKage and ABUSE

11. if you tell me the distance between the sideplates in INCHES...I will tell you the proper width you need Outside hook to outside hook dim.

12. Could use a torque wrench but, kinda overkill for a simple job.

PS: a Hummer screen is a different kettle of fish......that is a vibrating electromagnetic armature post bolted to a vibrating strip of steel in the centre of the wirecloth.

Hoping Santa Claus brings you GOOD VIBRATIONS for the season.

George Baker

MODERATOR

Originally Posted by angiehui

Hello, We are new to the sand quarrying business and have been running into a problem with our vibrating screen. After 20 or so hours of operation our steel woven mesh is splitting at the support beams. This is for our third layer used in screening 4mm sand. Attached is our screen design and how it's currently installed. We suspect the reason why the screen is splitting is due to the rubber mouldings breaking apart, causing the mesh to come in contact with the support beams and destroying it. As to why the rubber mouldings are breaking, we suspect it is a tensioning problem. How could this screen be better tensioned? What else could be improved to ensure longevity of the screen? Would appreciate any help that could be provided.

.....

Attached by Moderator:

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MUST give an adder answer here: WHY? I glanced at the pic, but answered from the words in the question........BUT, THIS PROBLEM may be a TOP DECK problem.

so....same theory applies below on most of those pointers for sure:

1. In the pic I see what I consider a very good thing on a top deck with large rock falling onto a 4" clear opening. I see FLAT TOP WIRECLOTH. Excellent vs standard weave wirecloth, so we have the crimp intersections lower by the thickness of the diameter of the wire....EXCELLENT.

2. SO top size will break standard crimped woven cloth as it is in the way of the material coming down......equals abuse.

3. I assume the diameter is probably .4375" diameter or .500" diameter...pls confirm

4. these big sections have a tendency to be hard to tension, they may or may not have BENT EDGES on them to hook into the tension side RAILS.

5. If just straight edges and the wire is just being HELD DOWN....then, YOU probably may have movement at the intersections of the weave. Most folks will utilized some J-BOLTS appropriately spaced around the deck to J HOOK the rails HARD DOWN to the rubber covered longitudinal support steel rails. no movement = no BREAKAGE.

.................

sorry..........I went off on a TANGERINE...below.........have a great day. GEORGE.

BOTH ANSWERS completely apply for heavy wirecloth or fine cloth on the bottom deck in their own area.

........................

Originally Posted by angiehui

Hello, We are new to the sand quarrying business and have been running into a problem with our vibrating screen. After 20 or so hours of operation our steel woven mesh is splitting at the support beams. This is for our third layer used in screening 4mm sand. Attached is our screen design and how it's currently installed. We suspect the reason why the screen is splitting is due to the rubber mouldings breaking apart, causing the mesh to come in contact with the support beams and destroying it. As to why the rubber mouldings are breaking, we suspect it is a tensioning problem. How could this screen be better tensioned? What else could be improved to ensure longevity of the screen? Would appreciate any help that could be provided.

.....

Attached by Moderator:

■

Please advise exactly how wide your screen is ...........it did not look that wide in the pic. ■

this reply is quite fascinating for me to read:

1. Original design was for PU....I assume polyurethane media?

2. Question: is the polyurethane one big piece with hooked edges OR flat panels with no hooks? OR other design like small 2'x2' squares plugged into a grid?

3. was the original deck a FLAT MOUNTING surface or did it have an "ARCH" on it?

4. the reason for these questions: if wirecloth, we NEED the ARCH or camber to bend the wirecloth over and STRETCH or TENSION over that arch, if you tried to tension wirecloth across a FLAT support frame with no ARCH...it WILL NOT TENSION...and it will break.

5. when installing polyu. it normally does not need to stretched over an arch....as it is completely different mousetrap then STRETCHING woven wirecloth.

6. Another little TIP: QUITE often, we need the speed stroke to be a little higher = operate at a higher exciting force or OPERATING G's to help activate the polyurethane but, not too much extra speed .... as to NOT breach the designed operating G's by the design engineers as to have the sideplate CRACK due to overexcitement of the BODY.

7. ON the math for the CAMBER heights across the width of the deck....JOHN GATELY being a design smart guy, may be able to share his wisdom here.

8. CLARIFY again for me: which deck is giving you thee MOST GRIEF? the FIRST OR TOP DECK or the SECOND or the THIRD?

We shall help you get er done.

George Baker

Originally Posted by angiehui

The width of the screen is 2.4m and it is 6m long, housing 3 layers.

The original design of the screen was for PU mesh, but it proved to be slow in processing the material with lots of blinding and plugging. The waste rocks coming out had a good percentage of sand with it. After numerous runs, we returned the first layer PU and changed both second and third layers to wire mesh. After reading your response and some research, we have since scrapped the rubber mouldings and changed them to PU type mouldings. Ive also removed the jbolts and tensioned the screen as best I can. On that note, we had to add height to the support rails in order to properly tension our screen and ive left 1" clearance on each side from the side plate. So far it seems to be an improvement to the old design but our work on the screen is not professionally supervised. The manufacturer of the screen is from China and is no longee taking calls. So left to our own devices we are just fumbling as we go. In the response to your thread you mentioned arc angle of the screen, is there a standard or a way of computing what ours needs to be?

■

WIDE SCREENS are another special thing:

1. if you only have one 8' wide area to bridge with one piece of wirecloth....THE wirecloth is DIFFICULT to hold down and keep tight. and the height of the rails under the wirecloth would have to be pretty high if stretching an 8' wide screen section over that width.

2. it is very typical for vibrating screen mfrs to in fact DESIGN a centre hold down strip in the centre of a wide deck so that you TENSION basically from the sideplate over to the centre and then install another piece of wirecloth from the centre hold down area to the opposite sideplate. hence, the support rails camber height would be great reduced ...a good thing.

Originally Posted by George Baker

this reply is quite fascinating for me to read:

1. Original design was for PU....I assume polyurethane media?

2. Question: is the polyurethane one big piece with hooked edges OR flat panels with no hooks? OR other design like small 2'x2' squares plugged into a grid?

3. was the original deck a FLAT MOUNTING surface or did it have an "ARCH" on it?

4. the reason for these questions: if wirecloth, we NEED the ARCH or camber to bend the wirecloth over and STRETCH or TENSION over that arch, if you tried to tension wirecloth across a FLAT support frame with no ARCH...it WILL NOT TENSION...and it will break.

5. when installing polyu. it normally does not need to stretched over an arch....as it is completely different mousetrap then STRETCHING woven wirecloth.

6. Another little TIP: QUITE often, we need the speed stroke to be a little higher = operate at a higher exciting force or OPERATING G's to help activate the polyurethane but, not too much extra speed .... as to NOT breach the designed operating G's by the design engineers as to have the sideplate CRACK due to overexcitement of the BODY.

7. ON the math for the CAMBER heights across the width of the deck....JOHN GATELY being a design smart guy, may be able to share his wisdom here.

8. CLARIFY again for me: which deck is giving you thee MOST GRIEF? the FIRST OR TOP DECK or the SECOND or the THIRD?

We shall help you get er done.

George Baker

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