Screw take-up selection criteria

Posted in: , on 31. May. 2016 - 15:19

Good day all,

What is the criteria for selecting the a screw take-up..?

E.g. I have an 83m long conveyor with a height of 5 m and I have selected a screw take-up, is this appropriate or the belt is too long ?

My thinking was I will still be able to pretension the ply belt enough to accommodate elastic stretch at start-up etc.

Thank you in advance for you valued feedback,

Best regards,

Mpho ■

Förderung
Transport
Antworten
Login to add a Reply
Roland Heilmann
(not verified)

Screw Take-Up

Erstellt am 1. Jun. 2016 - 10:26

Dear Mpho,

you need to consider the overall picture of your belt conveyor and your specific belt configuration. This will give you the basic information of

- required take-up length for tensioning

- residual belt elongation

- temperature and belt-sag induced take-up length

- reserves required for dismounting the take-up pulley / others

Then you check back against feasibility of a screw take-up in terms of

- force ( as per available equipment)

- length (as per available threaded rods)

- available sliding bearing.

You may try to search this forum, where some input has already been given in the past, e.g.

https://forum.bulk-online.com/showthread.php?25967

https://forum.bulk-online.com/showthread.php?9904

Regards

R. ■

Screw Take-Up Selection Criteria

Erstellt am 1. Jun. 2016 - 02:25
Quote Originally Posted by Roland HeilmannView Post
Dear Mpho,

you need to consider the overall picture of your belt conveyor and your specific belt configuration. This will give you the basic information of

- required take-up length for tensioning

- residual belt elongation

- temperature and belt-sag induced take-up length

- reserves required for dismounting the take-up pulley / others

Then you check back against feasibility of a screw take-up in terms of

- force ( as per available equipment)

- length (as per available threaded rods)

- available sliding bearing.

You may try to search this forum, where some input has already been given in the past, e.g.

https://forum.bulk-online.com/showthread.php?25967

https://forum.bulk-online.com/showthread.php?9904

Regards

R.

Dear Roland,

Thanks for your input. So my understanding from your input is that it's an individual judgment issue based on the factors you have listed above...

Best regards,

Mpho ■

Re: Screw Take-Up Selection Criteria

Erstellt am 1. Jun. 2016 - 08:38

Plenty of literature is available. 75 m is about the limit and your choice is whether or not to lash out CAPEX for a very slight risk of exceeding the limit length: which is not written in stone anyway. If you try to fit a GTU into 5m headroom you could run into trouble (depends on what else is there) and anyway it would look rather daft. A tower for a counterweight would look just as daft. Use a screw and winch hell out of the belt before splicing. Some punters dig a GTU counterweight pit for about 3m travel on a very short belt and install the drain sump etc as an afterthought. It just depends on how much money you have to throw at it. You could get screwed if you don't screw. I've fallen about laughing at one 35m boom conveyor with a GTU: especially because the boom was slewing. ■

John Gateley johngateley@hotmail.com www.the-credible-bulk.com

Roland Heilmann
(not verified)

Daring Question

Erstellt am 2. Jun. 2016 - 07:28

Dear Mpho,

to approach the three dots you've put: Yes, I hesitate to advise if I cannot see more of the picture. Usually one of the "old bulls" would cut in by requiring the base parameters of your installation as well as a "telling" sketch. For your parameters (length / lift) however I've seen both: gravity t-u as well as fixed t-u, and the decision was to be found only if all vital points were stewing in the pot together. Just as an example: If by any chance you happen to have a belt scale on your installation, gtu just would be the requirement.

For a fixed t-u however there are several solutions, not just only a long spindle but there's the grid step and the short spindle / movable support designs, where the take-up force is provided by an external means.

Regards

R. ■

Screw Take-Up Selection Criteria

Erstellt am 2. Jun. 2016 - 03:08
Quote Originally Posted by johngateleyView Post
Plenty of literature is available. 75 m is about the limit and your choice is whether or not to lash out CAPEX for a very slight risk of exceeding the limit length: which is not written in stone anyway. If you try to fit a GTU into 5m headroom you could run into trouble (depends on what else is there) and anyway it would look rather daft. A tower for a counterweight would look just as daft. Use a screw and winch hell out of the belt before splicing. Some punters dig a GTU counterweight pit for about 3m travel on a very short belt and install the drain sump etc as an afterthought. It just depends on how much money you have to throw at it. You could get screwed if you don't screw. I've fallen about laughing at one 35m boom conveyor with a GTU: especially because the boom was slewing.

Dear John,

Thanks for the reply. Would you mind to share some (one or two) literature reference/s for further guidance..?

Best regards,

Mpho ■

Screw Take-Up Selection Criteria

Erstellt am 2. Jun. 2016 - 03:15
Quote Originally Posted by Roland HeilmannView Post
Dear Mpho,

to approach the three dots you've put: Yes, I hesitate to advise if I cannot see more of the picture. Usually one of the "old bulls" would cut in by requiring the base parameters of your installation as well as a "telling" sketch. For your parameters (length / lift) however I've seen both: gravity t-u as well as fixed t-u, and the decision was to be found only if all vital points were stewing in the pot together. Just as an example: If by any chance you happen to have a belt scale on your installation, gtu just would be the requirement.

For a fixed t-u however there are several solutions, not just only a long spindle but there's the grid step and the short spindle / movable support designs, where the take-up force is provided by an external means.

Regards

R.

Dear Roland,

Herewith some further details below:

Material density / size: 1600 kg/m / -32mm

Conveyor Length and height : 83m /5 m

Capacity : 362 tph

Belt width : 600 mm

Belt Speed : 2.3 m/s

I look forward to your response.

Best regards,

Mpho ■

Roland Heilmann
(not verified)

Out & Over To Smbdy To Do A Proper Job

Erstellt am 3. Jun. 2016 - 07:24

Dear Mpho,

I'm sorry but I'll leave this line of discussion at this junction.

By reading at least my post of 1st of June you should have received the message that this is not a part-of-the-picture guesswork but a full set of information would be necessary to assess.

Without any negative judgement of your professional background, pls. accept the counsel to go & get substantial professional support at your place and pls. be prepared to accept market conditions for a warrantied service at your installation.

Regards

R. ■

Screw Take-Up Selection Criteria

Erstellt am 6. Jun. 2016 - 09:16
Quote Originally Posted by Roland HeilmannView Post
Dear Mpho,

I'm sorry but I'll leave this line of discussion at this junction.

By reading at least my post of 1st of June you should have received the message that this is not a part-of-the-picture guesswork but a full set of information would be necessary to assess.

Without any negative judgement of your professional background, pls. accept the counsel to go & get substantial professional support at your place and pls. be prepared to accept market conditions for a warrantied service at your installation.

Regards

R.

Dear Roland,

Thanks for your time and response. Although I am not too concerned about what your thoughts are regarding my professional background, I do feel that your last response was inappropriate especially on an open platform such as this. Sometimes its more respectable for one to acknowledge that they do not have a straight answer to a question than to go around in circles.

Regards,

Mpho ■

Roland Heilmann
(not verified)

Pls. Accept

Erstellt am 7. Jun. 2016 - 12:54

Dear Mpho,

I beg your pardon very much, but my wording was in no way intended to hurt your personal feelings.

The wording was selected to show my opinion that at this point in time it seems necessary to me that professional support be obtained by you and a hint was given that estimating the size of your request(s) you would need to be prepared to go to the engineering market, as schools / university / internet etc. would imo not provide the required services.

So, saying this bluntly without some cushioning as per post of June 3rd, would have been in my opinion a rudeness, but not the other way round.

Regards

R. ■

Screw Take-Up

Erstellt am 31. Jul. 2016 - 01:19

Dear Mpho,

As per my knowledge there are basically 3 Take-ups

1 ) Screw - Can be used for Conveyor lengths of short span and as per site conditions.

2 ) VGTU - Can be used for Conveyors which are very lengthy and of high lift.(I mean to say from Conveyor tail pulley on wards)

3 ) HGTU - Can be used for conveyors that are on ground.(As per your condition if we see you haven't written which material you are conveying and Site Conditions. For best example of HGTU if a Conveyor as a length of almost 80m. And In which 60m to 70m is horizontal and remaining 10 to 20m are inclined than we can use HGTU.) And not to mention if we go for Bagasse feeding in the shed area where the Customer usually asks for 40 to 50m Feed Area for a total length of say 70m some prefer Screw Take-up also.

Thanks & Regards

Ganesh Reddi ■