Originally Posted by Shakee

Dear Experts,

Is it necessary/advantageous to provide Automatic Take-up for short conveyors with higher capacities?

Regards,

Shakee

Dear Sir,

DO you mean hydraulic take up or is it Gravity take up.

Narayanan Nalinakshan. ■

Originally Posted by Shakee

Dear Mr.NarayananNalinakshan,

I meant the Gravity take up.

Regards,

Shakee

Dear Shakee,

It is always better to go in for gravity take up if the same is possible to be provided.

There are several advantages for gravity take up, main advantage is frequent adjustment not necessary.

Rgds,

Narayanan Nalinakshan ■

Dear Mr.Shakee,

If the center distances are below 50 meters , screw take-up may meet your requirements. Gravity take-up will not ask for the occasional belt tensioning. But it will be costly. You need to go additional two bend pulleys, if it is vertical take up. Or movable take-up trolley and sheave pulleys arrangement if it is horizontal take up.

If the drive pulley is ceramic lagged, frequency of belt tensioning may be greatly reduced, in screw take up arrangement.

Having detailed engineering may give you better solution.

Regards, ■

Dear Mr.Shakee,

To make you understand in a very simpler way: Cermic laggings have ceramic tiles embedded in a rubber lagging sheet. Thy have minor projections. They give better grip on the bottom cover of the conveyor, when drive pulley rotates. Hence the belt tensioning requirement compared to ordinary drive plain rubber lagging sheet, is less.

Ceramic laggings are much helpful, during monsoon to avoid the slippage problems, due to water entrapment , between the drive pulley and the conveyor belt.

Request to search in this forum. You may get more than 200 threads related with word "Ceramic". Hope this may help you.

Regards, ■

sganesh

You are correct as far as the elastic elongation but for the permanent elongation that only occurs during the intial break-in of the belt it will not make any significant difference whether ceramic or not. I would agree with sligtly reduced tensioning intervals but not greatly reduced. The tension will need to be continually adjusted until the permanent elongation is out of the system. The only advantage to a gravity take-up on this short conveyor is not having to do this intial adjustment.

For a conveyor that is that short that has no need for a gravity take-up it would be very difficult to justify the extra cost where a simple screw take-up will do the job.

Gary Blenkhorn

Moderator ■

To solve this dilemma we have developed the DSI Semi-automatic take-up system. The DSI system mounts screw take-up frames on a common slide carriage that buts up against compression springs of specified constant- K.

The problem with screw take-ups:

1. They provide no means of implementing the calculated tensions

2. Measuring belt sag between return idlers, using the rope formula, is not reliable as belts ten to cup across and the sag is different across the belt width

3. They make no allowance for tension loss due to the permanent stretch and frequent screw adjustments are required

The DSI Semi-automatic take up system offers the solution:

1. With the appropriate springs, selected for the application, bar scales measure the spring deflection and (deflection x K = T) the belt tension at the take-up pulley

2. Because of the spring deflection, belt relaxation does not immediately result in loss of belt tension. There is more time between and thus less, longer screw adjustments

3. Because of the bar scales, at the springs, the actual belt take-up tension is always known and therefore adjusted when required

Call or Email me if you wish to know more about the DSI Semi-automatic take-up system.

Joe Dos Santos ■

Hi Mr Shakee..

We have covered this all before in a previous thread.

Anyway.. basic rules:

- Up to 40m use a screw take-up

- Don't use a screw take-up if the conveyor has a concave curve

- You can use a fixed winch take-up for conveyors up to 1km (like underground)

- Use winch take-up with load cell control when coasting dynamics are a hastle

- Use gravity take-ups up to 4km long conveyors

- Use capstan brake passified gravity take-ups for conveyors over 4km and which do not have coasting dynamic hastles

- Belt type has direct influence on take-up design

Also.. never rely on the ceramic lagging to get you out of a fix. If you change out the pulley and replace it with rubber lagging you might just find yourself drowning in it..

Cheers

LSL Tekpro ■

If we ignore cost then it is always better to have an automatic take-up that you can walk away from and the desired tension is maintained.

I mentioned the DSI semi-automatic take-up which provides continuous conspicuous monitoring of the belt tension and also stretches out the time between adjustments and reduces the frequency of adjustments.

I have always had a problem with the complication and typically dedicated design for gravity take-ups, particularly horizontal gravity take-ups where the vertical clearance does not exist to permit a hanging gravity take-up. We thus have a preference for auto-hydraulic take-ups. They are more compact, lend themselves to standardization and repeatability and they allow for easy adjustment of thetension values if desired or required. Tension relaxation for maintenance, belt splicing, etc, is an easy thing.

Although I don't want to promote over-kill for a short conveyor I can say that we have had customers come to us for retrofit of existing short conveyors with both semi-auto take-ups and fully auto-hydraulic take-ups. In case of the fully auto we have worked up some very compact and economical designs.

Joe Dos Santos ■