4 replies to this topic

[Ghasem.Bashiri]

Dear Process Experts
I checked different practice for Steam Coil Sizing in Tank/Vessel without clear result.
Please help me with this issue:
Assume based on process conditions we need to use coil within a vessel/Tank.
Point1: When we use steam coil, Electrical heater or stab-in heater?
Point2: Is there any sizing procedure for Steam coil and Stab-in Heater?
Point3: Is there any excel or similar sizing program for Steam coil and Stab-in Heater?
Ghasem Bashiri

[ankur2061]

Ghashem,

Is it a batch heating application or a continuous heating application for your tank / vessel. Also is the tank / vessel having an agitator?

For batch heating using steam coil in a vessel, you can refer the book "Process Heat Transfer" by D. Q. Kern where the case of "BATCH HEATING: INTERNAL COIL, ISOTHERMAL HEATING MEDIUM" case is dealt in detail.

Regards,
Ankur.

[Art Montemayor]

Ghasem:

By the term “Stab-in Heater”, I presume you mean a conventional U-tube bundle that is flange–mounted on the side of the storage tank. It is also called a “Bayonet heater.

Point 1: I don’t understand what you mean by Point1. Is it a question or a statement?

Point 2: Yes. This subject has been thoroughly discussed in two of our Forums: http://www.cheresour...h__1#entry32963

And in our Spanish Fomum: http://www.cheresour...__10#entry45833

Point 3: You will find Excel Workbooks in both threads.

You should make use of our Search Feature and save a lot of time.

[Ghasem.Bashiri]

Dear Art

I checked the forum. It is related to heat loss from storage tank.
Actually I have continuous process, caustic storage.

During normal operation I have not probelm with process.
But during night or winter weather temperature can be cold.

Then I should keep my vessel temperature more that some value, e.g. 25-30°C.
In this case I am not sure about rate of steam that I need, possibility of using electrical heater or steam heater. and Finally size of steam coil that I need.

Ghasem Bashiri

[Art Montemayor]

Ghasem Bashiri

Thank you for giving us the basic data. Since you have a continuous process, the solution is much simpler. Usually what we do in your case is that we try to conserve the energy being lost in a continuous process – by insulating.

I presume that you have made a decision that your energy consumption is cheaper than the insulation capital cost and have opted for simply adding the energy lost to the environment. That means that you are at a situation that requires calculations on the heat energy being lost – very similar to what is done to calculate the insulation required to protect a hot pipe. You will find that calculation application in our Forum software section in the form of a spreadsheet.

Before you start to discuss the type, size, shape, or color of a heater required, you have to identify the rate of heat dissipation to the atmosphere. You calculate that rate ("Q") and use it to convert to the size of heater you need – whether electrical or steam. I hope this helps out.