Dear Rodsallik,

Have you duly considered taking-off/taking-away the moist sugar via pneumatic conveying instead of by mechanical conveyor? Pneumatic conveying methods can transport large quantities of materials over relatively short time periods. If you are transporting to a rotary dryer you can discharge the sugar via Cyclone collector.

Kind regards,

Kevin Layton

Sales & Engineering Manager

Columbus, Ohio USA

Main: 1+419.450.4404

E-mail: klayton@insight.rr.com

Skype: kevinlayton

Classifier Milling Systems

35 Van Kirk Drive, Unit #17

Brampton, Ontario, Canada L7A 1A5

Website: www.cms-can.com ■

The question is, if you put the sugar into a buffer bin above the conveyor will it flow out of the buffer bin into the following conveyor?

This is firstly a matter of bin design and with what appears to be a poor flow material. So get an expert to

1) measure the flow properties of the sugar

2) advise on the critical dimensions of the bin (flank angles and outlet dimension) according to the maximum residence time in the bin

3) then investigate the most suitable design of conveyor.

It can be difficult explaining to a client the difference between an average flow rate and an instantaneous flow rate. As you rightly point out 750 kg in 25 sec is 108 te/hr, while 750 kg every 3 minutes is 15 te/hr. Some people just can't understand the significance of this! (including some companies supplying materials handling equipment) ■

We discussed as best we could the bulk material properties, mass flow and live-bottom bin design and discharge opening as being critical elements of managing this solid flow. I was simply offering additional material handling alternatives to consider as he approaches his solution. Feel free to contact for testing and design. ■

I'm confused, there's nothing about this in the thread, only the suggestion of pneumatic conveying??? ■

Pneumatic conveying of wet sugar is not a good idea in any case. Build up will block the pipes in no time.

Mass flow hopper with a properly designed screw discharger can eaisly control the flow rate to a desired level. Alternatly a hopper with suitable outlet close to the vibrating conveyor making it work lile a vibratory discharge will also work.

Hopper wall angles will determine mass flow, opening will only prevent arching. ■

More details of the site layout and existing facilities are require to determine the most practical way forward. A well-designed buffer hopper with screw discharge to hold 700 Kg and feed out at 20 Te/hr will meet the requirements and clear before the next 'drop' is due, so mass flow is not essential so long as flow is reliable and the hopper clears well. However, if there is an existing vibrating conveeyor and space is tight, some other solution may be better. If details are send to lyn@ajax.co.uk, I would review and put forward an assessment of options. ■

How many centriguges feed to the vibrating conveyor? If there are three a 108 TPH conveyor may still be OK for handling 45 TPH from three centrifuges.

Better to avoid additional equipment under each centrifuge.Moist sugar is not easy to handle. In a sugar mill I worked, the vibrating conveyor was enclosed one and was used for partial drying of sugar. ■

At our refinery, we have three Centrifugals discharging to one Screw. We remove any access syrups at a spin time of roughly 60 seconds total, 84 seconds if you include wash times.

We use a solid steel screw (Auger.) I find this a very efficient method of transporting wet sugar to our Granulator to dry the sugars. It has a low build up rate, where it is stainless steel and most sugar will slide right off and up the screw.

I would suggest using a large Auger, with a 10 HP motor.

- Irvine A. Eatmon,

Sugar Boiler / Control Room Operator ■

Originally Posted by rodsallick

We have a situation in which a customer has centrifuges that discharge 750 Kg. of white sugar crystals onto a vibrating conveyor. The problem arises from the fact that the centrifuge discharges the 750 Kg. in 25 seconds and then runs for about 3 minutes until it discharges again, this translates into 15 tons/hour.

The problem is that when the centrifuge discharges 750 Kg/25 seconds, this translates to 750 Kg/25 seconds x 60 seconds/minute x 60 minutes/hour = 108 tons/hour.

As you can see now a very simple and inexpensive conveyor has to be built strong enough to withstand a constant feed of 108 tons/hour.

I would like to put a bin/chute below the centrifuge in order to retard the discharge of the sugar to about 2-1/2 minutes. There is enough clearance under the centrifuge to put a hopper/bin but I don't know if the sugar will flow at the rate of 2-1/2 minutes for 750 kg. Please note that the sugar has high humidity so it has the consistency of brown sugar.

I would appreciate your help.

If you contact the folks at US sugar in florida they can help you ■

Originally Posted by rodsallick

We have a situation in which a customer has centrifuges that discharge 750 Kg. of white sugar crystals onto a vibrating conveyor. The problem arises from the fact that the centrifuge discharges the 750 Kg. in 25 seconds and then runs for about 3 minutes until it discharges again, this translates into 15 tons/hour.

The problem is that when the centrifuge discharges 750 Kg/25 seconds, this translates to 750 Kg/25 seconds x 60 seconds/minute x 60 minutes/hour = 108 tons/hour.

As you can see now a very simple and inexpensive conveyor has to be built strong enough to withstand a constant feed of 108 tons/hour.

I would like to put a bin/chute below the centrifuge in order to retard the discharge of the sugar to about 2-1/2 minutes. There is enough clearance under the centrifuge to put a hopper/bin but I don't know if the sugar will flow at the rate of 2-1/2 minutes for 750 kg. Please note that the sugar has high humidity so it has the consistency of brown sugar.

I would appreciate your help.

sorry about the typo in the title my fingers get in the way sometimes

ask US Sugar what they do with thier centrifuges as the new plant they have in florida is a big one. ■

I work with the former Plant Manager of US Sugar, whom helped designed a lot of their plant Mr. Jack Thompson.

The suggested method is as mentioned above my self, to use a 10HP motor on a steel, rust-proof auger.

This allows the sugar to convey at a fast rate of speed, while not allowing clogging. ■

The duty esentially requires a buffer hopper to hold 750 Kg of damp sugar that will reliably flow into a feeder that discharges the contents at slightly more than the average rate discharged. It sounds easy, but I forsee a potential small disaster, with possible arching, and grains drying on the hopper walls and feeder to clog the system, if the user goes for a cheap system. ■

up to now you are right advised:

no pneumatic convey; but an auger

you may consider an chain conveyor too, designed for you product, with variable speed, dust tight, ... easy to clean and recover

let me send you a view of the chain conveyor ...

and let us wait for farder comments

regards

dirk

href="mailto:bulk.good.solutions.ar@gmail.com">bulk.good.solutions.ar@gmail.com

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