1) providing a supply of water

2) collecting the water and "muck" washed from the belt to avoid mess

3) drying the belt ■

1) providing a supply of water

2) collecting the water and "muck" washed from the belt to avoid mess

3) drying the belt ■

If you are considering a spray then I assume your material is moist & adherent. In those circumstances a good spray system has few disadvantages. Your spray bar should be near the belt and shrouded by the collecting trough. Level control in the trough ensures that the spray delivery matches the extraction rate. You will need hydrocyclones to clean the water for recirculating through the spray bar & a sedimentation collector to gather the sludge. A Hosch type scraper behind the spray bar is essential & this should be near a flat roller arrangement which provides high contact pressure to displace remnant adherent fluid into the trough.

This equipment requires a long trough which is still no longer than an ineffective, in those circumstances (assumed), driblings conveyor.

Any reasonable sludge pump will suffice; pump gland water cleaning cyclones will keep the spray nozzles working & for the high contact pressure you can consider using backing rollers. There will be some water loss since the boundary layer will escape and evaporate. Particles contained within the boundary layer will be displaced as dust. Did you say you wanted a clean operation?■

If you are considering a spray then I assume your material is moist & adherent. In those circumstances a good spray system has few disadvantages. Your spray bar should be near the belt and shrouded by the collecting trough. Level control in the trough ensures that the spray delivery matches the extraction rate. You will need hydrocyclones to clean the water for recirculating through the spray bar & a sedimentation collector to gather the sludge. A Hosch type scraper behind the spray bar is essential & this should be near a flat roller arrangement which provides high contact pressure to displace remnant adherent fluid into the trough.

This equipment requires a long trough which is still no longer than an ineffective, in those circumstances (assumed), driblings conveyor.

Any reasonable sludge pump will suffice; pump gland water cleaning cyclones will keep the spray nozzles working & for the high contact pressure you can consider using backing rollers. There will be some water loss since the boundary layer will escape and evaporate. Particles contained within the boundary layer will be displaced as dust. Did you say you wanted a clean operation?■

Originally Posted by louispanjang

A Hosch type scraper behind the spray bar is essential & this should be near a flat roller arrangement which provides high contact pressure to displace remnant adherent fluid into the trough.

Opinion on using an air knife to dry off the belt ■

Originally Posted by louispanjang

A Hosch type scraper behind the spray bar is essential & this should be near a flat roller arrangement which provides high contact pressure to displace remnant adherent fluid into the trough.

Opinion on using an air knife to dry off the belt ■

Hi there..

We have done belt washing systems since the early 80's.

Our first ones had faults which we have largely sorted out, but the followwing are the areas to watch:

- The water pressure must not be too high, or it splashes all over the place and makes a mess

- You need sufficient flowrate not only to wash the belt but also to provide a pumpable quantity as well as having nozzle sizes that don't block up

- Spray ahead of the belt scraper, and dry with a 100mm unlagged solid steel squeezer roller

- Make sure that your system is designed in such a cunning way that if the water flow fails, the belt wash chutes do not pack up with fine material requiring you to dig it out

- Make sure you have a very good system to handle the slurry produced

It took me a long time to get this right ... so..

Good luck

LSL Tekpro ■

Hi there..

We have done belt washing systems since the early 80's.

Our first ones had faults which we have largely sorted out, but the followwing are the areas to watch:

- The water pressure must not be too high, or it splashes all over the place and makes a mess

- You need sufficient flowrate not only to wash the belt but also to provide a pumpable quantity as well as having nozzle sizes that don't block up

- Spray ahead of the belt scraper, and dry with a 100mm unlagged solid steel squeezer roller

- Make sure that your system is designed in such a cunning way that if the water flow fails, the belt wash chutes do not pack up with fine material requiring you to dig it out

- Make sure you have a very good system to handle the slurry produced

It took me a long time to get this right ... so..

Good luck

LSL Tekpro ■

Originally Posted by designer

Opinion on using an air knife to dry off the belt

There was a hot aIr drying system on the REI/Anderson drift belt at Gasgoigne Wood built in the mid 80's; it worked very well.

Dewatering the belt is influenced by the carcass rigidity. The classy REI belt was strong & expensive and high contact pressure was thought to be better avoided. Further down the plant we had Scandura's knicker elastic belting and we could put pressure on those without too much worry.

Graham's 100mm roller is the same size we used but we had 2m belts and stiffened that roller with a pair of backing rollers resembling all-steel impact idlers, if you will. As stated..it takes a long time to get it right. ■

Originally Posted by designer

Opinion on using an air knife to dry off the belt

There was a hot aIr drying system on the REI/Anderson drift belt at Gasgoigne Wood built in the mid 80's; it worked very well.

Dewatering the belt is influenced by the carcass rigidity. The classy REI belt was strong & expensive and high contact pressure was thought to be better avoided. Further down the plant we had Scandura's knicker elastic belting and we could put pressure on those without too much worry.

Graham's 100mm roller is the same size we used but we had 2m belts and stiffened that roller with a pair of backing rollers resembling all-steel impact idlers, if you will. As stated..it takes a long time to get it right. ■

Originally Posted by louispanjang

There was a hot aIr drying system on the REI/Anderson drift belt at Gasgoigne Wood built in the mid 80's;

But hot air isn't really necessary is it?

http://www.aircontrolindustries.com/...sairknife.asp ■

Originally Posted by louispanjang

There was a hot aIr drying system on the REI/Anderson drift belt at Gasgoigne Wood built in the mid 80's;

But hot air isn't really necessary is it?

http://www.aircontrolindustries.com/...sairknife.asp ■

Hot air is not necessary...

The 100mm squeezer does a good job of drying the belt, as long as it has a good inprint into the belt.

We normally spray first, then scrape, then scrape again (by which time there isn't much water left) then squeeze the last of the water off.

Cheers

LSL Tekpro ■

Hot air is not necessary...

The 100mm squeezer does a good job of drying the belt, as long as it has a good inprint into the belt.

We normally spray first, then scrape, then scrape again (by which time there isn't much water left) then squeeze the last of the water off.

Cheers

LSL Tekpro ■

Hot air is no more obligatory than steam cleaning. It was there to thoroughly clean the belt. You cannot completely remove a boundary layer by mechanical means alone, regardless of the pressure applied to the surface; unless the pressure is sufficient to force the removal device beneath the boundary layer and on into the belt; say no more, say no more. In most belt conveyor applications water is a contaminant anywhere on the belt no matter what it carries in suspension. So a clean belt should be dry & a convenient way to ensure that is by evaporating the water off in a controlled manner.

It rather depends on what you call clean. ■

Hot air is no more obligatory than steam cleaning. It was there to thoroughly clean the belt. You cannot completely remove a boundary layer by mechanical means alone, regardless of the pressure applied to the surface; unless the pressure is sufficient to force the removal device beneath the boundary layer and on into the belt; say no more, say no more. In most belt conveyor applications water is a contaminant anywhere on the belt no matter what it carries in suspension. So a clean belt should be dry & a convenient way to ensure that is by evaporating the water off in a controlled manner.

It rather depends on what you call clean. ■

Really.........

Why would you want to wash and blow dry a belt? Are these belts in a fashion show or on TV?

I do mining applications, and the object of belt washing is to make sure you don't get any carry over that causes piles of fines under the return idlers if you don't turn the belt over and you have tricky material on the belt.

Normal belt washing with squeeze drying works just fine. Most of my conveyors are outside where we get rain which often wets the belt again.

Underground mines are pretty wet too. The thing is to get the belt clean, which is what I have done with belt washing in applications that needed it.

LSL Tekpro ■

Really.........

Why would you want to wash and blow dry a belt? Are these belts in a fashion show or on TV?

I do mining applications, and the object of belt washing is to make sure you don't get any carry over that causes piles of fines under the return idlers if you don't turn the belt over and you have tricky material on the belt.

Normal belt washing with squeeze drying works just fine. Most of my conveyors are outside where we get rain which often wets the belt again.

Underground mines are pretty wet too. The thing is to get the belt clean, which is what I have done with belt washing in applications that needed it.

LSL Tekpro ■

Dear Mr.Graham Spriggs,



What is the meaning of Squeezer rollers?

Is it a pair of rollers fixed after the external scrappers at discharge pulley?

I guess one straight roller is fixed above and one is fixed below at the return side conveyor.

The conveyor will be slightly pressed between these two rollers?

Am I correct ? Will not this arrangement aggrevate the wearing out of top cover of the belt?

Request someone who knows to post a photo or diagram of squeezer rollers.

It will help us (the members) to understand better.

Thanks & regards, ■

Dear Mr.Graham Spriggs,



What is the meaning of Squeezer rollers?

Is it a pair of rollers fixed after the external scrappers at discharge pulley?

I guess one straight roller is fixed above and one is fixed below at the return side conveyor.

The conveyor will be slightly pressed between these two rollers?

Am I correct ? Will not this arrangement aggrevate the wearing out of top cover of the belt?

Request someone who knows to post a photo or diagram of squeezer rollers.

It will help us (the members) to understand better.

Thanks & regards, ■

Originally Posted by sganesh

Dear Mr.Graham Spriggs,



What is the meaning of Squeezer rollers?

Is it a pair of rollers fixed after the external scrappers at discharge pulley?

I guess one straight roller is fixed above and one is fixed below at the return side conveyor.

The conveyor will be slightly pressed between these two rollers?

Am I correct ? Will not this arrangement aggrevate the wearing out of top cover of the belt?

Thanks & regards,

A long flat 100mm roller pushing against the belt can be used on the dirty side to dislodge some of the carry over in a dry application. It is a squeezer.

In the old days we used it in conjunction with a "Rapper roller" which also dislodges the dirt by rattling the clean side of the belt on top. Hence the phrase a "Rapper and squeezer".

For belt washing the same sqeezer roller is used to dry the belt. It does this because there is no gap between the squeezer and the belt for the water to pass though. It builds up and pours off the bottom of the rotating sqeezer. Indeed many installations also have a flat hold down roller on top of the belt to assist, but never directly above the squeezer, and also you never have a rapper in a belt washing application.

Any cover wear is negligible..

Cheers

LSL Tekpro ■

Originally Posted by sganesh

Dear Mr.Graham Spriggs,



What is the meaning of Squeezer rollers?

Is it a pair of rollers fixed after the external scrappers at discharge pulley?

I guess one straight roller is fixed above and one is fixed below at the return side conveyor.

The conveyor will be slightly pressed between these two rollers?

Am I correct ? Will not this arrangement aggrevate the wearing out of top cover of the belt?

Thanks & regards,

A long flat 100mm roller pushing against the belt can be used on the dirty side to dislodge some of the carry over in a dry application. It is a squeezer.

In the old days we used it in conjunction with a "Rapper roller" which also dislodges the dirt by rattling the clean side of the belt on top. Hence the phrase a "Rapper and squeezer".

For belt washing the same sqeezer roller is used to dry the belt. It does this because there is no gap between the squeezer and the belt for the water to pass though. It builds up and pours off the bottom of the rotating sqeezer. Indeed many installations also have a flat hold down roller on top of the belt to assist, but never directly above the squeezer, and also you never have a rapper in a belt washing application.

Any cover wear is negligible..

Cheers

LSL Tekpro ■

In the UK, the roller with the high contact pressure was called a Squeegee roller. Squeegee roller had its connection with the proprietory types of domestic mop and was coined because the action in that particular application was one sided. The proximity of backing rollers suggests that Squeezer is a more appropriate name.

Rollers are chosen precisely because of their low wearing action...rolling.

It rather depends on what you call clean....the conveyor in question was often on TV in its early days. After it got the mine treatment & settled down to being just another dirty old pit belt its modelling days were over. The UK mines are gone & not missed. The debris is simply dirty water under the bridge.■

In the UK, the roller with the high contact pressure was called a Squeegee roller. Squeegee roller had its connection with the proprietory types of domestic mop and was coined because the action in that particular application was one sided. The proximity of backing rollers suggests that Squeezer is a more appropriate name.

Rollers are chosen precisely because of their low wearing action...rolling.

It rather depends on what you call clean....the conveyor in question was often on TV in its early days. After it got the mine treatment & settled down to being just another dirty old pit belt its modelling days were over. The UK mines are gone & not missed. The debris is simply dirty water under the bridge.■