BenjaminM
Chemical
- Dec 12, 2006
- 86
We have a batch solution around 75*C that is charged to a process vessel to be cooled. The tank has a jacket and coils. We circulate tempered water though these and slowly over several hours lower the jacket temperature to cool the batch down. As we cool the solution down, our product precipates out of solution.
We cool the batch slowly because it helps make large fluffy crystals that are easier to separate out down stream. We have to regulate the agitator speed to around 40 RPM to prevent damanging the crystals.
Over time product builds up and coats our coils. Over several months, the 3" pipe may develope 2 to 3" of build up. As this happens, heat transfer obviously drops off, and our 4 hour cooling times turn into 8 hour or more.
Once this extra time becomes the bottle neck of the process, we fill the tank up with water, dissolve the product, and send it to waste water. Needless to say, a substantial amount of product and money is lost by this practice.
With the constraints of slow agitation, and with out adding anti-scaling dispersences to the product, are there any reasonable ways to prevent buildup on coils?
We cool the batch slowly because it helps make large fluffy crystals that are easier to separate out down stream. We have to regulate the agitator speed to around 40 RPM to prevent damanging the crystals.
Over time product builds up and coats our coils. Over several months, the 3" pipe may develope 2 to 3" of build up. As this happens, heat transfer obviously drops off, and our 4 hour cooling times turn into 8 hour or more.
Once this extra time becomes the bottle neck of the process, we fill the tank up with water, dissolve the product, and send it to waste water. Needless to say, a substantial amount of product and money is lost by this practice.
With the constraints of slow agitation, and with out adding anti-scaling dispersences to the product, are there any reasonable ways to prevent buildup on coils?
