Red Clay In Class 8 Rear Dump Trailer 1

[rc0213]

We make a Class 8 rear dump trailer, full frame. A customer is having problems with the trailer dumping red clay. The trailer goes to 43 degrees, as designed. The cylinder has no issues going all the way up. The trailer has a HMW Liner. They are working in the South.

They pulled the trailer to the manufacturing plant. When the trailer was at 43 degrees, we could see a lot of red clay still in the dump body. It pretty much covered the floor and the radius corners. And, none of it moved when it articulated up to 43 degrees. The customers says they have men going into the trailer and manually dumping.

The question is, what are our options as an engineer to fix this for the customer? Someone suggested a vibrator kit. Would that help? Our initial thoughts are that because of the red clay, and it is sticking to the liner and body, it probably won't fix the issue. We are looking for options to solve this issue.

Thanks,

 

[hokie66]

Vibration won't help. Clay is cohesive, and the cohesion varies with different types of clay. Red clay in the South can stick like glue. Maybe they need to place a plastic sheet in the trailer before loading.

 

[hokie66]

With a google search, some haulers recommend spraying the trailer lightly with diesel. Not my idea, just saying...

 

[cvg]

HMW or UHMW sheet should work fine. maybe they need to let the clay dry out a bit
mix with lime?

 

[IFRs]

Spray with vegetable oil?

 

[EdStainless]

Don't they spray cement mixers with paraffin oil, that might help here also.
You might do some tests with samples of different plastics to see if one helps more, but I doubt it.

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P.E. Metallurgy, Plymouth Tube

 

[dvd]

I second the cohesive clay notion from hokie66. Companies like Jenike and Johanson can test the materials and let you know that it is sticky, officially.

If the supplying vendor is not on the hook for a dump bed that handles this material, then don't accept responsibility.

A live bottom dump bed which would be a continuous belt conveyor with belt scraper/cleaner at the exit end of the dump bed would force the material out IF the clay wasn't sticking fiercely to the side walls.

It may work to use a one-time-use polyethylene sheet liner for each load that would allow the material to slide out, as already suggested by hokie66.

 

[rc0213]

Thanks all for your suggestions.

I was talking to a construction company. And, they mentioned using concrete form oil. I was thinking some kind of oil. The only stipulation is that the customer is using the red clay for commercial use. So, my concern is would using the concrete form oil affect the red clay?

I was thinking also if we can put a UHMW material liner. Could we coat the liner, with something permanent, so that they won't have to apply the concrete form oil?

 

[dvd]

CEMA 550 has some procedures for material testing, but you can surely devise your own test to see floor and wall cohesion.

Get some clay and start testing on different surfaces, tilting up from horizontal. Wet clay is going to be stickier, so don't convince yourself of anything without assessing just how wet this clay can get.

 

[LittleInch]

You need to pretty careful here. Anything which doesn't move when you have a trailer lifting is liable to tip over. It only takes 5 degrees off vertical and it may well rollover.

A very thin water layer might do the trick or insert some very small holes in the trailer and pump a water film in before tipping it.

think of an air hockey table but with water. A bit extreme maybe, but if you're going to be hauling this for months / years its a better way and doesn't do anything to the product.

If you've already got a plastic liner yu might be able to get one with holes built in?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[3DDave]

I'd get some Tyvek house wrap and cover the bed with that if oil/lubricant contamination is a problem. It'll add a bit to the cost of material but save on time to drop off. It may be reusable. It looks to be $170/150 ft X 9 ft roll, so 3 trailers worth to cover the floor if you can't get it back, and maybe more if only the top half of the slope is underlayed.

 

[JStephen]

Maybe try a thin layer of sand on the bottom of each load?
Do bobtails go any steeper?
I'd be very hesitant about the oil solutions. I think that is (or was) common with asphalt, but there, you have a petroleum soaked product anyway. Soil contamination can run into a lot of money in a hurry.

 

[chicopee]

I would use a fire hose supplied by a fire hydrant. Even a garden hose connected to a water faucet may work may work.