Heat Exchanger

How in the heck can the tubing have a diameter of 6 cm (ID or OD?) and have a thickness of 4 metres? Is the spiral diameter an OD, ID or on tubing center?

What do you mean by capacity?

Does the coil contain the process fluid or the heat exchange medium?

What is the geometry of the rest of the heat exchanger?

Do you understand basic geometry?

If these questions aren't enough to daunt you... and if you can answer them, maybe we can help you.

Oops, sorry, I make mistake. Dimension of spiral coil is OD=6cm, ID=5.2cm, thickness=4mm. Diameter outside tube 84cm and fill with palm oil. How to calculate calorie capacity of heat exchanger if dimension of HE is L=116.4cm W=116.4cm H=243cm and thickness=4mm?

Can you help me??

Thanks for the additional info.

More questions:

• What is flowing inside the spiral coil?
• What is its flow rate?
• What is flowing in the shell outside the spiral coil (it wasn't clear if the palm oil was inside the coil or outside)?
• What is its direction in relation to the flow through the coil?
• What is its flow rate?

After I know these, I will need to know the feed temperature of both, and the desired temperature of the process fluid as it leaves the heat exchanger.

Are these accurate general representations of your heat exchanger?

Which one is yours, countercurrent or cocurrent?

that's my heat exchanger

In order to give you either an answer or at least a hint you should provide either the 2 pipe diameters or one of them and the wall thickness and one of the helix diameters specifying which one it is.Those data concern the geometry. Some other concern the flow since the convection depends on the fluid velocity. It could be estimated that the hot gas will give more via radiation than via convection but the oil will get heat via convection so that the oil flow has to be specified. With the data it is possible to estimate a global heat transfer coefficient and multiplying it by the area obtain the heat transfer capacity of your exchanger.

Still not enough to go on.

Answer these questions:

1. What is the temp of the oil entering the Heat eXchanger (called HX from now on)?
2. What is the desired temp of the oil exiting the HX?
3. What is the flow rate of the oil through the HX?
4. What is the fuel used to heat the oil?
5. What is the flow rate of the fuel used to heat the oil?

I ask some of these questions a second time. Is there some reason you did not answer them, providing only a drawing instead (which was very good and descriptive by the way!)?

If you cannot answer these questions, you will never get an answer to your questions.

Bye

Good day...

Sorry because I forget answer your question before.

1. The temp of the oil entering the HX is 173°C.

2. The desired temp of the oil exiting the HX is 183°C.

3. The flow rate of the oil through the HX is 3kg/cm2.

4. Burner to heat HX use diesel fuel with nozzle 4 gph & 5 gph. Total of the nozzle is 9 gph. 1 gph = 3.7854 liter/hr.

5. The material of spiral HX is stainless steel with ρ = 7870kg/m3 & C = 0.472 KJ/Kg°C.

6. The oil have ρ = 890.1 kg/m3 & C = 0.472 KJ/Kg°C.

7. Long of spiral from the up to the bottom which out from HX is 193 cm.

8. Dimension of HX is 116.4x116.4x243cm and the thickness is 4mm.

If you need more information, you can ask me. Thanks for your help..

That'll fool the revenooers, who are probably looking for copper...

Presuming that t = 0.4 mm, spiral o.d. = 84, and neglecting the very slight slope of the coil,
V_internal = 18 [π (0.26)²][π (78)].
A_surface = [π (0.6)][π (78)].

Q = k A_surface (lmtd). I don't know the k-value (heat conductivity) for your fluids with SS316 between.

from where 78?

is 0.6 from 6 cm

I'm sorry many ask cause I confuse...

Oops, my mistake. I thought it was 6mm (= 0.6cm) tube, probably because that is a common size.

I presume that you mean "convection" ? In fact the thermal resistance of the metal pipe is VERY small in comparison with the convection limits. In general the fluid with the lower convection coefficient is circulated in the pipe to increase speed and convection and the fluid with the higher is outside since even at lower speeds convection can acceptable. As an example oil is inside and water outside in an oil-water cooler. In the case of an oil-air exchanger for instance the convection area on the air side is increased by fins.