Take the 2-minute tour ×
Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free, no registration required.

I am designing a Tube heat-exchanger, similar to this:

Heat exchanger image

My process requires water (at room temperature, 18C ~ 22C) that is being pumped out of a small tank (300 Liters) to be heated in a heat-exchanger to upto 65C. I have to use steam from a small steam generator (which we have to purchase) to heat that water.

The primary purpose of the system is to pump out water from a small tank (300 Liters) with a pump and spray it in another tank with a nozzle for cleaning the tank. Once the water is sprayed in the final tank, it will be drained. For effective cleaning, we need the water heated to around 60C ~ 65C.

I am looking for advice or a way to calculate how to design a simple heat exchanger for the system. The data i have at hand is the flow rate of water out of the pump, which is around 35 Liters per minute. The pipe at the pump outlet will be Stainless Steel, 1/2" in diameter (OD).

Can any one point me in the right direction or help me calculate the following :

1) Size of outer shell of heat exchanger, 2) Size/Diameter of inner tubes of heat exchanger, 3) Number of inner tubes (or passes) of heat exchanger, 4) Steam flow-rate to achieve my desired results.

Thanks. Zee

share|improve this question
Hi Zee, and welcome to Physics Stack Exchange! I'm not sure if this is quite on topic here; in general this site is more for conceptual questions rather than questions about how to build things. I'll have to see what the community's thoughts are. –  David Z Dec 6 '11 at 21:57
I'm quite shure that this is off topics. And Zee: physicists do not know about such things. I had to learn that to a certain extent, and I found that "heat transfer" business horrible (Incredible complicated and results are very inaccurate). As a practical solution for Your purpose: Buy a steam injector. This small and inexpensive apparatus mixes the steam into the water and voila! –  Georg Dec 6 '11 at 22:19
Thanks George, but we can not "inject" anything into the water. We might need to buy something off the shelf, but since i have some time on my hand and since i can play around with some mechanical stuff, i was wanting to try my had at it. I only need or am looking for TU or heat transfer calculations to give me a picture of how things will go and then i can determine sizes or other parameters for the applicatino. –  Zee Dec 6 '11 at 22:22
You spoke of a steam generator that You are going to purchase. Thus You will have steam to inject, right? If You insist to delve in that disgusting business then google for "heat transfer". BTW. Heating water in a recuperator (the correct name for what You call a heat exchanger) to 65 °C is complicated, because You have to maintain a partial vaccum on the steam side, and You need a barometric drain to get the condensed water out of the vacuum. –  Georg Dec 6 '11 at 22:38

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.