dampening roller temperature

[ar17]

any idea what is the recommended temperature in the dampening section? input temperature is at an average 11C and in the return it is measures at 32C, is this normal? thanks. i'm comparing a komori and CD-102... thanks

[Dan Roll]

I suspect you are experiencing 'diesel effect'. When a liquid is compressed (in this case by pumping it through a system in which it is required to pass through some restriction, maybe from a hose to a smaller diameter fitting, for example) heat is generated. If this is the case, this is the result of poor plumbing and should be fixed.

[Green Printer]

any idea what is the recommended temperature in the dampening section? input temperature is at an average 11C and in the return it is measures at 32C, is this normal? thanks. i'm comparing a komori and CD-102... thanks

Where are you taking the temperature readings? Are you measuring temperature in the pan where the water enters and the drain side where it exits? How long of a distance must the chilled water travel from the circulator to the press.? Are the water lines insulated?

[Kaoticor]

Your input temperature seems fine, however, the return seems hot... Might be good to check the temperature actually in the pan then you can go from there.

[Erik Nikkanen]

I suspect you are experiencing 'diesel effect'. When a liquid is compressed (in this case by pumping it through a system in which it is required to pass through some restriction, maybe from a hose to a smaller diameter fitting, for example) heat is generated. If this is the case, this is the result of poor plumbing and should be fixed.

Just a comment. One can not compress a liquid. But for sure, heat can be generated due to friction losses in the pump and piping resulting in a small temp increase. Closed loop systems can heat up quite a bit without cooling but with cooling not very much.

[Alois Senefelder]

Hello ar17

You mean Fountain Solution Temperature?

The F.S. in the pan should be held at a constant level - - Inflow/Outflow hoses via

the F.S. refrigeration central circulator should be - Insulated


Regards, Alois

[Dan Roll]

Perhaps you are unfamiliar with how a diesel engine works; the fuel (a liquid) is contained in a cylinder that reduces in volume, compressing the liquid to the point it reaches its ignition point and burns, generating a larger volume of gas, depressing the compression device (the piston, in this case). Fountain solution can be heated by the same process, I have seen many installations where the fountain solution is pumped into the press refrigerated and returns heated (on one press I observed, it was actually hot). This is usually due to a powerful return pump forcing the liquid through a restriction.

[Erik Nikkanen]

Perhaps you are unfamiliar with how a diesel engine works; the fuel (a liquid) is contained in a cylinder that reduces in volume, compressing the liquid to the point it reaches its ignition point and burns, generating a larger volume of gas, depressing the compression device (the piston, in this case). Fountain solution can be heated by the same process, I have seen many installations where the fountain solution is pumped into the press refrigerated and returns heated (on one press I observed, it was actually hot). This is usually due to a powerful return pump forcing the liquid through a restriction.

Sorry Dan, I didn't know how poorly you understand high school physics. So there is no point in trying to correct your view.

[jbeniston]

I would be looking for a temp in the tank of 10.5 C in the trough(s) on the press of 12.5C and at the return to the tank of not more than 15C.
You have to find out where in the circuit the temparature rise is ocurring and correct it.
It doesn't really matter what type of press you are using or working on the temparature of the dampening fluid certainly should not be rising from 11 C to 32C.

[turbotom1052]

i make it a point to adjust the incoming flow into water pan to flow as high as the return can handle without overflowing the water pan. By doing so you are assuring that fountain solution is not stagnating in the pan and collecting heat.