I can hardly belief that you are experienced in the fields you are indicating! Using plastic buckets to elevate a highly abrasive product like clinker ensures certainly an interesting spare part business. Proper dimensioned steel buckets, preferably with suitably designed wear lips are the right solution for clinker.

Holger ■

It is hard to belief that one states to be experienced in elavating clinker, cement coal and fertilizer and asks for plastic buckets! Using plastic buckets to elevate a highly abrasive product like clinker ensures certainly an interesting spare part business. Having supplied more than 2000 elevators preferably to the cement industry we think that proper dimensioned steel buckets, preferably with suitably designed wear lips, are the only solution for clinker and recommandable for cement and fertilizer.

Holger ■

Dear Mr. F Gambarotta,

There will be many companies making plastic buckets, presently I have literature of plastic bucket manufacturer mentioned below; incidentally I got it from them in Singapore.

BRAIME Elevator Components Limited.

Leeds, England

Fax.: 0532 435021

Regards,

Ishwar G Mulani.

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

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 5882916 ■

I notice Dr. Holger Lieberwirth of Beumer comments regarding plastic buckets handling cement, coal and fertilizer. I have used plastic buckets in these three areas with excellent results.

It should be noted the plastic used should be polyurethane and the second point to make is that the buckets wear from the inside out and not from the outside in. The wear on the outside is mainly due to the dredging and this can be overcome by putting in steel buckets with a wear lip and a projection larger than the plastic bucket say every 2 metres. The wear rate in the bucket is also a related to the velocity of the material exiting bucket and the co efficient of friction between the product and plastic.

It has been shown that the lower the co efficient friction the less the wear.

The size of the bucket Mr Gambarotta is requesting in not practical and appears to be close to the old DIN 15234 standard. Using such a size bucket would create major problems, such as holding it onto the belt etc. Suggest using multiple rows of buckets.

However sometimes the economics of plastic buckets don’t stack up.

Would be happy to assist in designing an elevator for you.

Roy Segal ■

Braime is a good source. They have companies or representation in other parts of the world.

TAPCO and Maxi Lift good sources also. They have representaton around the world too. ■

Hi Roy,

you are certainly right that the wear of an elevator bucket depends a lot on the design parameters of the whole elevator. Starting from the proper feeding, avoiding spillage by proper bucket spacing, bucket size and positioning the infeed relativ to the tension pulley as much as possible and not ending with the proper discharge just inbetween gravity and centrifugal discharge to avoid sliding of the product along the bucket wall (outer or inner) and recirculation.

No doubt, Polyurethan, in particular high density PU, is a product well proofen in certain wear protecting applications. The costs for the material and the making of the buckets versus the durability of the buckets led so far to an almost exclusive application of steel buckets in extremely abrasive materials like clinker (with coal it may be a different story depending on the quality; for bucket elevators, handling grain plastic buckets are quite common).

Using buckets with a larger steel projection at every fifth bucket to cut free the elevator bottom may be possible, However we would not recommend it, since it requires larger elevator shafts than necessary for 80 per cent of the buckets. Morever, it may lead to certain dynamic effects which adversly influence the durability of the mechanical components. We developed the concept of the "dynamic bottom" which operates successfull in quie some applications with sticky or other "difficult" materials.

Holger Lieberwirth ■

Hi Holger,

The use of plastic buckets for handling coal and fertilizers (Phosphates and super phosphates) from my point of view is a better solution than steel buckets for the following reasons:

•When handling these products moisture is normally a problem hand hence a corrosion issue with plastic buckets this is not an issue. However this can be overcome in metal buckets by using stainless steel. Once again an economic decision.

•With plastic buckets there are no sharp corners for the product to build up in as with a fabricated bucket.

•When handling coal there is no sparking issue with plastic buckets and most of the better ones are anti static. Once again one could use stainless steel.

•An important factor we have found is with maintenance is that plastic buckets are lighter and easier to handle.

In the cases I have provided plastic bucket the product has been sticky and the plastic buckets have provided a good solution both technically and economically.

Please note I am not a supplier of plastic buckets just a supporter of them.

Roy Segal ■

Don't forget if you change to plastic buckets, have sufficient belt tension to give an adequate tension ratio at the head pulley to ensure a friction drive without slip. ■

Hy Roy,

you are right. At least for fertilizer we allways use stainless steel buckets. They operate very well there.

Holger ■

Dear Sir,

We are manufacturing Pure Nylon Bucket Elevator Belts, light in weight and best in quality, most economical, gives better life.

Please contact us for supplies or samples.

Best regards,

S.V.G.Acharya

email ID: acharyasvg@yahoo.com ■

Dear MR.F.Gambarotta

I am very much pleased to inform you that I am manufacturing best quality Plastic buckets. The literature is herewith attached. Kindly go through it.

I am also sure you will be surprised to go through the quality of our Bucket Elevator Belt. Once given a chance I am sure you will be very happy with the quality of our belt.

Kindly go not hesitatte to give me a chance. I am from India.

Best regards,

S.V.G.Acharya

■

Hi Roy,

Where are U working now???

From the cement background, I can say that we use steel buckets - as these are what has been supplied by the OEM.

Considering the high reliability demanded upon the machines and b/elev do have their issues - I would not be game to try plastic.

I do ackowledge your points.

Wehn we do belt changes - all of the buckest come out and go back on..

Brand X has a steel flat bar on the inside whihc is handy for small hoist lift point - buckets weigh 30kg each

Brand Y does not have these - more difficult to handle.

We have done 20 buckets/hr placement for brand X and only 10/hr for brand Y.

I would wish that OEMs would design/size their buckets so that they can be easily stacked on conventional wooden pallets - this is for handling when the belt is changed out.

Cheers

James ■