When you say wet sand do you mean the material is moist?
We use (on one of our units) what's called an air prep, basically cools and dries the air.
And on our second plant we have used three full lengths of galvanised pipe with fittings on the ends, the air passes through and cools down. It's like a giant intercooler.
There hasn't been nearly as much caking since we cooled the air. We have three moisture traps though.