Re: Help With Basic Belt Conveyor Concepts
You certainly can't equate stupidity to youth. Who called for a GTU on a 65m flat conveyor carrying 50 tph? ■
John Gateley johngateley@hotmail.com www.the-credible-bulk.com
Re: Help With Basic Belt Conveyor Concepts
Dear Mr JohnGateley
Thank you for replying to my question.
"You certainly can't equate stupidity to youth"
Yes, I would like to prove to the other experienced engineers that I'm not silly just becasue I'm young. I do occasionaly ask dumb questions, but I like to think that is just due to my lack of experience and my enthusiasim to learn. Any way isnt there supposed to be no dumb questions only dumb answers. But I must admit there replys arnt always appreciative of my desire to learn, more along the lines of lets humiliate the young guy. I just hope it doesn't start to extinguish my enthusiasm.
"Who called for a GTU on a 65m flat conveyor carrying 50 tph?"
It was part of the specification by the production and maintenance depts that will take "ownership" of the equipment. I did think it was excessive since I can recall that GTU's are normmally for longer conveyors eg >100m. But being the Young&Silly guy Im keeping my mouth closed until I have all the facts.
I am pretty sure they want the GTU because Maintenance doesn't want to have to be responsible for adjusting a manual tensioning system and Production doesn't trust Maintenance to do the adjustments when required. I guess it basically boils down to they want "install and forget" equipment.
Thanks again for your reply & would appreciate any coments you have about the other items I listed
Young&Silly ■
Conveyor
Now that you have muddied my polo field and poured wood byproducts on it.
(1) Rubber lagging is generally installed on the head pulley and twin drive pulleys only.
(2) The gravity take up needs to be right behind the drive unit.
(3) Why are they giving you three options for motive power size?
What is the belt speed? what are the speeds of the downstream conveyors if any?
(a)Are they offering three different belt drive speeds through three different gear boxes?
what is your down stream acceptance capacity?, this will rule all!
When you say gear motor that automatically says hydraulic drive. please be more specific as belt driven hydraulically requires more information from you.
(4) The rule of thumb for training idlers is 1 training idler every tenth troughing idler and one training idler for every tenth return idlers.
(5) By using the 400 MM you are maintaining a continuity of parts, replacement pullies and bearings and reducing the stress on the belt by reducing the wrap angle.
What is the desired wrap angle?-this will rule the belt purchase as the thicker the belt the shallower the wrap angle to reduce belt carcass stess and damage esoecially when dealing with chevron cleats as they will break off!
Is the conveyor belt steel framed or cable supported?
What type of conveyor control are you using?
conventional, PLC, low voltage?
what type of speed switches are offered?
What is the desired voltage and phase?,
Is it 220, 480, 600, 1000 three phase AC alternate current? or single phase? 220 volt? what is the rated amperage? remeber that you will have a spike of 1.5 times the rated amperage at start up.
What is the power feeding the plant/conveyor system?
34,500 to 4,000 volt with stepdown transformers at the pole or switch yard? Is the power feeding your plant conditioned with a regulating transformer to avoid line drop?
Have they included fire suppression, guarding, or coveyor covers in their quote?
What are the drive elements of the conveyor? reduction gearbox, full hydraulic drive, with a fluid coupler or conventional reduction gear drive through a rubber or chain coupler to a chain and gear to gear drive unit? Or a head pulley drive motor all in one?-these are great if you have the head room.
Where are the belt cleaners?, is a head pulley scraper in use or a tail pulley plow? Do they recommend a beater tail pulley to help keep the belt clean?
What type of conveyor splices are suggested or offered? Are mechanical, cold vulcanised, hot vulcanised?
Get thee to the CEMA web site.
Get thee to the OSHA web site.
Get thee to the SAE web site or doom is sure to follow.
the problem is you have not told us everything and your suppliers have not told you everything at least from what I read here.
John, George My humble apologies if I overlooked something.
Leon ■
Re: Help With Basic Belt Conveyor Concepts
Selamat pagi,
Wood chips stick to rubber like .... to a blanket. I have seen wood chip accretions turn a presumably cylindrical snub drum into a big bar of Toblerone. Talk about shake rattle & roll. If your maintenance people can't be arsed to tension the little belts they are hardly likely to adjust the cleaner are they. Don't even mention cleated belt cleaning!
It seems like you are working for a firm of North American cattle ranch employees. There's no 'w' or 'b' so I can't be talking about Cowboys, can I?
When its all gone wrong tell them I said so by all means & in the meantime don't worry. It is obvious that you have a feel for the business. ■
John Gateley johngateley@hotmail.com www.the-credible-bulk.com
Re: Help With Basic Belt Conveyor Concepts
Dear lzaharis;
Thankyou for your reply and sorry to hear about your Polo Feild.
Please find my answers to your questions and some additional qquestions below;
"The gravity take up needs to be right behind the drive unit."
What would be the bad effects and how large if the gravity unit is put in the middle of the system. Because it is seems this is where management would like to see it located for non-engineering reasons.
"Why are they giving you three options for motive power size?"
As per my original message, There are 4 companies quoting this conveyor and they all have recomended different motor sizes.
"What is the belt speed? what are the speeds of the downstream conveyors if any?"
Belt speed will be around 60m/min to achieve the required capacity. There are no isues with downstream conveyors etc.
"When you say gear motor that automatically says hydraulic drive. please be more specific as belt driven hydraulically requires more information from you."
No, it is a Gear-motor in the form of an electric motor with a built-in/on gearbox. These seem to be a common item around the facility with SEW, Flender and ABB being the more popular brands and capacities ranging about 1kw - 15kw.
"Is the conveyor belt steel framed or cable supported?" The structure will be Steel I beam construction 10m-15m of the ground.
What type of conveyor control are you using?
conventional, PLC, low voltage?
what type of speed switches are offered?
This is upto the electrical dept, but I wouldnt have thought this would not impact on mechanical design issues?
"What is the desired voltage and phase?"
it will be 425/3/50.
"Or a head pulley drive motor all in one?-these are great if you have the head room."
This sounds like an interesting option, could you give some links to suppliers or other technical info on these. But would this make for a more complicated and expensive motor change in the event of a motor burn out? We get severe electrical storms 2-3 times a week every week in Malaysia, so burnout from lightening strike is always a risk.
"Where are the belt cleaners?" I think they are all proposing rotating brush cleaner just after the drive/outfeed drum.
"What type of conveyor splices are suggested or offered? Are mechanical, cold vulcanised, hot vulcanised?"
They havent mentioned splice type in there quotes, what would you recomend for this type of conveyor?
Thanks again for your help
Young&Silly ■
Re: Help With Basic Belt Conveyor Concepts
Dear Mr John Gateley
Terima Kasih for another reply.
I think you will be right about the wood chips being sticky.
What would you recommened as the best cleaning method.
The current quotes I have all mention rotating brush after the drive roller. Is this suitable/good/bad/disaster?
"I have seen wood chip accretions turn a presumably cylindrical snub drum into a big bar of Toblerone."
Only one mentions a snub roller so I assume the others arnt using one, maybe becase of the problem you mentioned. But wouldn't the stuff then just build up on the first iddler roller?
Young&Silly ■
Re: Help With Basic Belt Conveyor Concepts
Yes. Rubber & wood chips are both forest products & seem to have a natural affinity. Scrape it, brush it or even solvent wash it: whatever you do will remove rubber along with the other resinous matter. Steam or hot washing would remove most of the crud & soften the job for a good follow up scraper. Perhaps somebody has developed polymers which do not have such affinity for forest products; they should have by now.
Chain or en masse conveyors on the other hand would solve all your problems.
Assuming your belts are indeed fireproof?? Anticipated accretion can grow to the point where the belt drag is insufficient to lift the belt to permit rotation. A sort of sliding chordal effect. Lets invent that term. So now the resin impregnated belt is rubbing over wood chips. In pre-history such a situation would have been the finest firelighting ceremony around. Your supplier comments should be quite interesting. ■
John Gateley johngateley@hotmail.com www.the-credible-bulk.com
Conveyor Etc.
Originally posted by Young&Silly
Dear lzaharis;
Thank you for your reply and sorry to hear about your Polo Feild.
Please find my answers to your questions and some additional qquestions below;
"The gravity take up needs to be right behind the drive unit."
What would be the bad effects and how large if the gravity unit is put in the middle of the system. Because it is seems this is where management would like to see it located for non-engineering reasons.
"Why are they giving you three options for motive power size?"
As per my original message, There are 4 companies quoting this conveyor and they all have recomended different motor sizes.
"What is the belt speed? what are the speeds of the downstream conveyors if any?"
Belt speed will be around 60m/min to achieve the required capacity. There are no isues with downstream conveyors etc.
"When you say gear motor that automatically says hydraulic drive. please be more specific as belt driven hydraulically requires more information from you."
No, it is a Gear-motor in the form of an electric motor with a built-in/on gearbox. These seem to be a common item around the facility with SEW, Flender and ABB being the more popular brands and capacities ranging about 1kw - 15kw.
"Is the conveyor belt steel framed or cable supported?" The structure will be Steel I beam construction 10m-15m of the ground.
What type of conveyor control are you using?
conventional, PLC, low voltage?
what type of speed switches are offered?
This is upto the electrical dept, but I wouldnt have thought this would not impact on mechanical design issues?
"What is the desired voltage and phase?"
it will be 425/3/50.
"Or a head pulley drive motor all in one?-these are great if you have the head room."
This sounds like an interesting option, could you give some links to suppliers or other technical info on these. But would this make for a more complicated and expensive motor change in the event of a motor burn out? We get severe electrical storms 2-3 times a week every week in Malaysia, so burnout from lightening strike is always a risk.
"Where are the belt cleaners?" I think they are all proposing rotating brush cleaner just after the drive/outfeed drum.
"What type of conveyor splices are suggested or offered? Are mechanical, cold vulcanised, hot vulcanised?"
They havent mentioned splice type in there quotes, what would you recomend for this type of conveyor?
Thanks again for your help
Young&Silly
The gravity take up needs to be directly behind the drive unit to provide traction.
Motive power: It all depends on the shock loading of the belt and how heavy the material is-there is no absolute guarantee with weight of wood chips.
Conveyor control: this will have an effect on mechanical issues if it is done poorly due to operation of the conveyor under load i.e. poor speed switch selection, belt drag-high amperage conditions, frame stress at the head pulley drive unit, hard start versus soft start sequence.
motorised head pulley:
I think I remember the brand name is JOKI-google motorised head pulleys in parenthesis.
*If you have frequent electrical storms you are going to have problems no matter the drive type
due to lightning strikes -
An easier way is a hydraulic motor drive belt
the power pack is all in one unit and uses no gear reducers-check them out at the CEMA web site
or look at Conveyor Componenents Corporation
and or Hagglunds
If you use any thing less than a hot vulcanised splice or splices and the required number of training idlers for troughing and return you will have problems period.
Your turn for the next chuckka the field is still wet. ■
Help with basic belt conveyor concepts
Hi,
I am a Young & Silly (well thats what the experienced guys call me) engineer in my first job after graduating.
I have been asked by my boss to look over and evaluate some proposals from 4 local companies submitting quotes for about 10 belt conveyors of various configurations. So I would like some independent comments/advice on a few issues.
The conveyors are in the range 20m to 65m long and 600mm to 11200mm wide and most are 3 or 4 ply plain rubber belts, although some of the steeper belts have chevron type 'tread'.
The conveyors are used to handle wood chips, wood flakes and saw dust.
For simplicity I will pick one conveyor; 65m long centre to centre, 900mm wide belt 3ply rubber belt with 20deg side trough rollers, 50,000kg/hr of wood chip with bulk density of 200kg/m3 and traveling horizontal. Vertical Gravity takeup.
In particular I need some help to understand and sort out the vendors proposals. I would like to make sure my report to my boss is a good one, cause I want to try and shake off the Young&Silly nick name ASAP
In particular I am trying to understand and sort out the merits of the different proposals in a few key areas
1) Does the rubber laging need to be only on the drive and tail drums, or should the three rollers at the gravity take also have rubber coating or is this just wasting money?
2) Should the gravity take up be closer to the drive, tail or centrally located?
3) The vendors are quoting different gear motor sizes (7.5kw, 11kw and 15 kw), what should be the correct rating?
4) The number of auto aligning roller assemblies varies from "2 on top and 2 on return strand" thorough to "4 on top and 4 on bottom". How many are really necassary? I am thinking, 1 midway along the top, 1 about 5m before the drive, then on the return side 1 about 5 m before the gravity take up and then 1 about 5m before the tail is this correct or does it really need 4 on top & 4 on bottom
5) All have proposed 400mm dia drive, tail and main gravity roller. But 2 vendors are quoting 200mm 'In' & 'Out' rollers to the main gravity roller while the other 2 are quoting 400mm dia'In' & 'Out' rollers, what is the correct sizing?
I really will appreaciate any and all advice.
Thanks in Advance
Young & Silly ■