"A perception exists that this machine is breaking the sulphur granules and generating dust"

What is the physical evidence. Perceptions are just that!

"The "thick" blades are 16mm. The "thin" blades are 3mm to 5mm thick.

The blades have been used with and without varying numbers ot teeth, and there is no apparent change."

If teeth and thickness are so irrelevant you are left with speed and depth of cut. Have these been quantitatively examined?

"In my opinion, the machine in question operates in a very consistent manner across the stockpile with minimal deflection, bounce or vibration."

So what is the problem other than 'opinion' and 'perception'?

"Has anyone experienced similar issues for the same perceived reasons?"

Not this kid.

"Is there a mechanism that exists that would cause the problem.

Sulphur granules are not especially fragile and take some effort to fracture."

The only mechanism of influence is inter-particle behavior. If the UNIDENTIFIED particles are as resilient as claimed then there must be resident dust which is being disturbed and there is sod all you can do about that other than modify the upstream process and/or fit some expensive dust control equipment.

You, or the plant, need to quantify the problem. ■

Hello,

Earlier respondent Mr. John Gateley has already analysed the issue in depth and has also given the important information. I add the following:

1) You have doubt or apprehension that machine is creating more fines. To verify this, make sieve analysis of some 10 to 15 random samples taken across the stockpile face. Then reclaim small module and take 10 to 15 random samples from the reclaimed material on the outgoing conveyor. Repeat this exercise in next shifts / days so that you have sufficiently large number of samples with respect to material ‘lot’. Then compare the sieve analysis of the samples from stockpile and samples from outgoing conveyor. This will enable to conclude whether machine having 16 mm thick blades is creating more fines, and to what extent. It is to be noted that some / marginal increase in fine occurs inevitably whenever the material reshuffled.

2) You have said that flights have been tried with and without teeth, but not varying thickness. So, why not to try for this ? You can try for a flight thickness of say 6 mm (you have said 3 to 5 mm are also okay), and then in this case also take samples and make sieve analysis as said before.

3) Check that the scraper chain speed, travel speed and depth of cut (as applicable) are proper as per supplier of machine. You can also compare their values with the other machines you are referring.

4) Gentle handling of material always reduces degradation of material. The scraper drive is likely to have squirrel cage induction motor. If this is fed by variable voltage - frequency panel, then you can try to reclaim at say 75% of speed, etc. and see for result. This is likely to reduce capacity. This suggestion is of general nature. Its suitability for implementation subjects to yes / no opinion from machine designer and supplier. If it is yes, then machine suppliers involvement will be essential to make the collateral adjustment in other operational features such as travel speed, etc. The issue of the sr. no. 4 concerns some changes in machine operation and therefore it is advisable that its recommendation for implementation should come from the machine supplier, in consultation with you.

Regards,

Ishwar G. Mulani

Author of Book: Engineering Science And Application Design For Belt Conveyors (new print November, 2012)

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: conveyor.ishwar.mulani@gmail.com

Website: www.conveyor.ishwarmulani.com ■