Heat load estimate 1

[zpiderman]

We bought an old Thermolator heat exchanger. The name plate gives the following information:
Model# SMO 1810 Serial# 33-0351
Power 220 Amp. 35 Ph. 3
Control 110 Cycle 60
Wiring print: 124A-1
Thermolator Co.
Division of Van Dorn Co.
Indianapolis, Ind.

It's basically an electric heat exchanger whereby the process oil (I'm not sure what kind) is heated using metal rods attached to a power supply. There is a requirement for cooling water to regulate the oil temperature.
I have been trying to find the manufacturer of this unit but with no luck.
I would like to know what my cooling water requirement is knowing that the operating temperature is between 100 and 700 degrees F.
This is the only information I was able to find:
Oil pump - 1.5 HP, 16.8 USGPM (@S.G. of 1)
Heat exchanger - 12" Dia. and 33" high, 9 U-shaped rods approx. 64" long and 0.375" dia.

Can anyone give me a clue as to where to start, formulas to use, etc.? Can I get a good estimate by finding the electric-to-heat power? How?

 

[TripleD]

I believe to get a good estimate of the cooling requirement you would have to establish a few things first, namely the total tube heat transfer rate, which can be estimated by the q(conv) = mass flow rate x specific heat of the oil x (Outlet temperature - Inlet temperature). So you could try the above which should give you a ball park figure and then look for a book on heat and mass transfer for example" Fundamentals of Heat and Mass Transfer" by Frank Incropera and David P. De Witt.

 

[MortenA]

The max effect you could get for something with 220 V 35 Amp would that not be 220*35=7700 Watt?

Best Regards

Morten

 

[TRIPLE]

Morten:

I agree with you, but in today's industrial environment where costs of projects are monitored very carefully, I think "Spiderman", should do the job right the first time, rather than have an inefficient heat exchanger on his hands. The calculation of energy via the Power calculation should serve as a check on the calculation via the Newton's law of cooling, not vice versa.

 

[MortenA]

I only answered the easy part (about electric heat. And im quite certains that the stated duty is the max case on witch he should design the cooler. He dont need to check against the heat input - the HX should be able to deal with the max heat-input as far as I have understood his question.

All the heat from the electric heater must go into the oil (or the element would explode sooner or later.

Then assuming (as a worst case) that there are no other cooling (from environment or cooling load from the stuff that he wants to heat in the oil bath in the first place) he can base this HX (the cooler) on this load. I assume that there is some sort of cooling medium regulator so that when there is a cooling load then the cooling is reduced.

Best Regards

Morten