Do the simple thing and buy a self dumping flip flop batch dumping scale weigher.

Here is your solution

www.bagging scale.com ■

Dear Mr lzaharis,

For any type of belt weighing,it is extremely important to have a fairly constant feedrate,since the mechanical slugishness of the system could affect the accuracy to a great extent. In your case you have mentioned thet the feedrate could vary from 2.5 TPH to 24TPH which is a very large variation. Pls give a detail process requirement to understand your precise requirement & recommend to you a suitable measurement method. In corporating an weighing system without understanding the pros & cons could land you with a solution which can be a liability.

P.J.Talreja ■

Dear Mr. Joe,

The material flow rate can be measured by belt weigher. However, if the quantity of material on belt happens to be very low during some of the time then accuracy of the weighment will be less. It would be better if you specify the purpose of this weighment and sensitivity of the related equipment / process, to the accuracy of the weighment. Whether this weighment is controlling any important process and your required accuracy during variation in flow rate at minimum feeding and at maximum feeding. The belt should be straight without any curvature etc. Possible specific answer depends upon the overall requirements and installation and finally the opinion and the recommendation of the belt weigher manufacturers.

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.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916 ■

Mr. Mullins,

Rate of flow from a conveyor belt scale is a common requirement. Depending on the accuracy needed you can also measure flow with impact flow meters or even amp loading on the drive motor. The expected accuracy of using a single idler belt weigher would be in the range of +/- 1/2%. This is assuming the conveyor is suitable for a belt scale. On conveyors with light belt loading, keeping spillage and material carry back to a minimum will also increase system performance. If you would like more info, please drop me an email.

PS: I'm a yankee and am not bright enough to think in metric.

.5 mtrs/sec = 1.64 fps = 98 fpm

24 tonnes/h = 26.5 tph = 52920 lbs/h = 882 lbs/h

max loading = 9 lbs/ft ( which is kinda light )

5 tonnes/h = 1.88 lbs /ft ( which is very light )

Assuming 4 ft. idler spacing, your net loading is only 7- 1/2 lbs at 5 tonnes per hour

You might consider slowing the belt speed to increase loading ■

We manufacture conveyor belt scales used in many low flow rate applications, i.e., scrap, wood chips, plastic pellets, etc. If the scale is installed properly and the belt protected from environmental factors, such as wind, you should have no problem weighing in this range.

Michael Murphy

http://www.beltwayscales.com ■

Dear Sir,

Please use RADAR type belt scale. Please contact K-TECK.

Regards.

A.Banerjee ■

Your range of feed rate would be not good for an in line measurement from the bin. Read the info from Todd above, the cement industry have been weighing this type of flow rates and ranges for years, they slow the belts to get good measurements for their blending.

bruce.erickson@bulkprosystems.com ■

Dear Mr.Joe,

As per your specifications your belt Load varies from 1.3kg/m at lowest feed rate to 13.33kg/m when the feed rate is maximum. If this load is going to be there always we can think of goung in for 4 or 6 nos of low capacity load cells based belt scale. Kindly confirm.

Thanks & regards

V.Sundar

Newton weighing system Pvt Ltd

A8 Rajdanga Nabapalli

Kolkata - 700 107 India

Ph: 091 33 2442 9991

Mob: 091 9830425045

Email; newtonws@gmail.com ■

Dear Joe,

The 24" wide belt wikt a speed of 0,5 m/sec. is able to transport approx. 65m2/h resp. 46 t/h for the product with the lowest density.

The maximum capacity to be transported is 24 t/h.

You can reduce the speed of your conveyor down to o,25m/sec. what will result in a load per meter twice as much that will extend the accuracy of your system.

There is no technical advantage to use the the Gamma system.

The weiging system will be a lower investment.

For optimizing the accurancy of the weighing system you could use a frequency controlled drive in order to obtain the maximum load on the belt.

Kind regards

Johan Brands ■

Dear Joe,

Lodestone specialize in low throughput weighing systems. We have recently completed a number of system weighing paper and plastic waste with a nominal throughput of 5 tonnes per hour. This material is fed from an extruder which gives a very variable rate onto the conveyor and can reach up to 20 t/hr. The engineering phase is critical to work out the parameters on of the conveyors.

If you are interested, get in touch and we will send you a data sheet so that we can assess your project.

regards

Jon Scarrott

Lodestone Electronics Ltd ■