help with belt conveyor cooling system

[JP123]

Hi,
I a have some conveyors that carry very hot iron pellets. They use water to cool the belt conveyor and that create steam every where in the galleries. Is there an other way to cool the belt conveyo?

Thanks!
JP.

 

[swearingen]

You could use some high-speed exhaust fans shortly after the water is added to aid in steam removal as well as cooling by evaporation.

 

[JP123]

yes but the pellets create steam all along the galleries that mesured almost 150ft. is there an other coolant media that we can use?

 

[dvd]

Is the water used only to cool the belt? Or are the pellets being cooled also?

How hot is "very hot"?

How big are the pellets?

What kind of belting are you talking about?

Do you have to use belted conveyors?

I have some ideas but you need to be more specific.

 

[JP123]

yes the water is used only to cool the belt to prevent the deterioration of the belt when the pellet fall down on the belt

the pellets are 1/2'' diameter and between 300-400 deg F

the belted conveyors are already in place and it will be to expenses to change them..then i have to find a way to aspire this steam or eliminate it or decrease the temperature of the pellets before they go on the belt and after in the galleries because that create corrosion in the galleries and create moisture into the dust collector ducts

 

[MintJulep]

Step 1 is to determine the maximum allowable temperature of the belt.

Step 2 is to calculate how much heat you actually need to remove.

Practically speaking, your options are air and water.

It is possible that using either more water, or colder water will do the job. Remove all the heat from the conveyor as a sensible heat gain only in the water - no phase change, no steam.

Or, do your cooling within a controlled enclosure that the belt passes through. Exhaust the steamy air outside. Use air knifes on the entry and exit.

 

[dvd]

Step 3 from above is to look at a woven metal belt running on a herringbone slider surface. Depending on your loading there are plenty of choices. Call Cambridge or Maryland Wire Belting.

Or since the pellets are getting cooled by the belt coolant, why don't you just quench them and convey cool pellets.

Are you trying to keep the heat in the pellets? Is this a troughed belt conveyor? Give us an idea of material loading in lb/min and belt speed.

 

[JP123]

i dont think they are trying to keep the heat in the pellets

the average speed of the belt is 300 fpm and the loading is about 625 ton/hr

in the past, they sprayed pellets with water into the chute and aspire steam in the galleries with fans..i think that was not so bad

 

[dvd]

Since I work for a company that sells conveyors most of my solutions will come from that angle. It sure sounds to me like someone is going to have to decide to spend some money to solve this problem.

A quick calculation gave me 20,833 lb/min of iron pellets and at 300 ft/min on a 150 ft long conveyor you've got about 10,500 lb of iron loaded on the belt at any instant. I know that you could get a metal belt that could handle that but it would mean changes.

Have you looked into replacing the existing belt with a silicone rubber belt? Silicone belting can handle temperatures around 500F. I imagine that there is somebody out there that makes a belt that can handle your product and not burn up or break. Possibly you could change the belt without making any other changes.

 

[PeterCharles]

I think you have a few options, but you probably won't like them :-
1) Keep the belt system and fit covers over the belt with an extractor fan system to pull off the steam/water vapour produced.
2) Fit a quench unit prior to the belt then convey cooled pellets, ensuring sufficient residence time in the quench unit to take out the heat from the pellets.
3) Submerge the belt ensuring there is sufficient water to prevent the water temperature getting so hot it produces water vapour.
4) Use a wire mesh belt running over a plenum supplied with air so that you air cool the pellets during conveying. (I've seen this on briquetting plants).