The item you are referring to is a conveyor belt hold back device or head pulley brake which is mounted on the head pulley shaft of the conveyor carrrying the load up an incline, in which it prevents its rolling backwards when the belt is loaded preventing a spill of material and plugging up a transfer point.

If you visit the www.cema.org web site you will find the information they have regarding the brakes/hold back units or you could contact Mr. Nordell through his home page to ask about them.

lzaharis ■

Originally Posted by john zhu

Dear all:

Could you please help me to find some catching devices when conveyor belt broken suddenly?

Thanks

Dear Mr.John zhu,

Could you please let us know the reasons for your belts snapping?

Thanks & regards, ■

If the belt gives up the "ghost" suddenly, there is a device marketed by ASGCO Mfg. that will catch a runaway belt & keep it from leaving a path of destruction back down the conveyor and the belt in a indistinguisable "wad" at the bottom of the slope. However, it is wholly dependent on where it is monted and where the break occurs. If it breaks below the device, it is useless. Also, if this is an extrordinarily heavy belt, I am not sure how effective the device would be in holding it. I am sure the manufacturer can advise. Hope this is helpful....

Buddy Wilson

Applications Engineer / TSM-Southeast

Fenner Dunlop Americas ■

Hi,

You can also install the anti roll back rollers developed and manufactured by Megaroller, seemed a very smart option but you do need to install the correct amount for the individual system.

If you want additional details I can send through the information provided by Fenner Dunlop Australia.

Drop me your email and I will forward the information:

peter.thorpe@rescan.com.au

Kind regards, ■

All the devices indicated are simply concerned with holdback.

What device can stop a runaway take up carriage?

Last week I was presented with a design, for approval no less, where the take up trolley ran on inclined rails. Belt breakage would allow the counterweight to drag the trolley through the first sheave, demolishing said sheave in the process. The side deflector sheave would then drag the trolley sideways so that it would also demolish the nearby handrailing (and anybody walking nearby). It is not the first time I have been presented with such deathtraps, and by highly reputable companies. Belt breakages do happen. ■

Dear all,

I am just posting my idea. All of you would have seen the safety harness(Belt) and used safety belts in automobiles in the seats. The safety belts will allow you gentle movements. But if there is any sudden movements, it will not allow you to move and keep you safe.

Can the above principle work for the take-ups of conveyors also? If such devices are available/developed and connected suitably in take-ups, it may allow the take-ups for gentle movements. ( This may be more appropriate for conveyors connected with Variable speed drives where the starting of the conveyor would be very smooth. ) But when the conveyor is snapped, it will hold the counterweights in position which will avoid the potential threat to equipmets & human life.

If such devices are available, please post the contact addresses.

Thanks & regards, ■

Dear Mr. John,

In case of horizontal conveyor, if the belt snaps, the belt monitor switch will trip the drive and drive will stop. As far as belt and material is concerned, it will come to stop in very short time due to friction opposition and will stay without damage to other things.

As for the sharply inclined conveyor, the loaded belt on carrying run will tend to slide down and similarly the return belt will also tend to slide down. For arresting such downward slide, you may refer to the manufacturers of such devices if available (so far I have not used such device). The grip to the belt is by pulley, but this will become null and void when there is no tension. In such situation, the external device will have to try to grip the belt. Such device may be responding to sudden fall in the value of tension.

As for the snapping of belt location, in all probabilities it will occur where there is maximum tension. So in case of inclined conveyor, the belt snap is likely to occur near head end, in case of decline regenerative conveyor, such snapping is likely to occur at the tail end. So, locate such device accordingly and as per the rule of statistics generally belt will fail at those locations and holding system is likely to be successful in its mission.

In India regarding the bulk material handling systems of importance / concern (like power stations, ports, cement plants, big mines, etc); the general rule is to avoid such occurrence by preventive care / maintenance. The operating personnel and shift engineers keep watch on belt condition and take the remedial measures as necessary.

Regards,

Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyors.

Author of Book : Belt Feeder Design and Hopper Bin Silo

Advisor / Consultant for Bulk Material Handling System & Issues.

Pune, India.

Tel.: 0091 (0)20 25871916

Email: parimul@pn2.vsnl.net.in ■

Originally Posted by sganesh

Dear all,

I am just posting my idea. All of you would have seen the safety harness(Belt) and used safety belts in automobiles in the seats. The safety belts will allow you gentle movements. But if there is any sudden movements, it will not allow you to move and keep you safe.

Can the above principle work for the take-ups of conveyors also? If such devices are available/developed and connected suitably in take-ups, it may allow the take-ups for gentle movements. ( This may be more appropriate for conveyors connected with Variable speed drives where the starting of the conveyor would be very smooth. ) But when the conveyor is snapped, it will hold the counterweights in position which will avoid the potential threat to equipmets & human life.

If such devices are available, please post the contact addresses.

Thanks & regards,

Any certified lift manufacturer will be able to supply the safety arrestors used on their products, or at leasr point you in the right direction.■

I suggest you use a belt arrestor,

In the event that the belt snaps or broken the belt arrester senses the loss of tension and immediately clamps the belt and thus the belt is helt thightly.

You can visit this website to find a wide range of the said devices: http://www.ico.co.za/techinfo.htm ■