8 replies to this topic

[golegolegole]

Hello all,

I have a simple system where I need to find out the steam pressure that will be required for heating a batch reactor. 

I have all the data related to the vessel itself, all the process parameters and also the design specifications of the Limpet around the batch reactor. However, I am not able to decide upon the pressure of the steam that might be required for efficient heating.

I know that high pressure steam usually provides better LMTD and low pressure steam usually better with Heat Transfer itself. Is there nay way to calculate the pressure accurately. 

Also will the steam pressure change the amount of steam required by the batch very largely? 

For reference, the vessel is of 7kl capacity, in which 5kl batches will be produced and a non exothermic reaction takes place inside the reactor. The temperature needs a ramp from 25 to 85 deg C and with the lowest time possible. The batch is continuously agitated and also vapors will not be present in the system until 120degC. Pressure is 1.6 bar_g.

Thank You.

Mihir Gole

[breizh]

Hi,

The requirement is to get a saturated steam to guarantee an efficient transfer. About the quantity of steam, I invite you to look at a steam table ( latent heat vs Pressure)

Most probably a 4bar absolute will do the job, temp 143.6 C. 

Is your product thermal sensitive?

Learn about steam the principles of steam engineering, with Spirax Sarco

Breizh

[Pilesar]

Steam utility for industrial use is usually provided at defined increments and not generated to suit individual pieces of equipment. What steam levels do you have available for heating? You should have only two or three choices. Try each of them in your model to see which give an acceptable result. You may find that the choice is similar to what Goldilocks made: one is too hot, the other is too cold, the third choice is just right.

https://www.thermope...m/content/1176/

Edited by Pilesar, 10 April 2024 - 05:32 AM.

[latexman]

There are physical limitations to worry about too.  With this small RX it probably isn't a problem, but what is the MAWP of your limpet jacket?  That will set a boundary condition to the steam pressure.

[golegolegole]

Thank You breizh for the prompt reply, I was also able to recall some similar steam pressures of 3.4 barg used for a similar sized reactor in my previous industry. However, the references you provided do not actually provide any methods for calculating the steam pressure and flowrates. Hence, I am not sure how you came up with the value of 4bar. It would be very helpful if you can share your line of thinking. 

Thank You,

Mihir Gole

 

 

Hi,

The requirement is to get a saturated steam to guarantee an efficient transfer. About the quantity of steam, I invite you to look at a steam table ( latent heat vs Pressure)

Most probably a 4bar absolute will do the job, temp 143.6 C. 

Is your product thermal sensitive?

Learn about steam the principles of steam engineering, with Spirax Sarco

Breizh

[golegolegole]

Thank You Latexman, so we have considered a steam pressure of 7-8 barg. as the boundary condition for our heating process. This is not due to the limpet itself but due to the restriction of our boiler we consider buying for this purpose. But the limpet itself has a MAWP of 10 barg. 

There are physical limitations to worry about too.  With this small RX it probably isn't a problem, but what is the MAWP of your limpet jacket?  That will set a boundary condition to the steam pressure.

[golegolegole]

Thank you Pilesar, so this reactor is the only equipment as of now that we have which requires heating. As the plant is small scale, most other things including the distillation column reboilers currently run on electricity. As we are expanding the plant, we intend to use steam for more efficiency and cost savings compared to elec. Hence, there is no constraint on the pressure of steam that might be used. We currently plan on treating 3 barg steam as a MP Steam in our plant. Thank You

 

Steam utility for industrial use is usually provided at defined increments and not generated to suit individual pieces of equipment. What steam levels do you have available for heating? You should have only two or three choices. Try each of them in your model to see which give an acceptable result. You may find that the choice is similar to what Goldilocks made: one is too hot, the other is too cold, the third choice is just right.

https://www.thermope...m/content/1176/

[breizh]

Hi,

My reply was based on 20 years' experience in batch process (latex, resins, API).

Nothing theoretical but from pilot studies where all the parameters are defined for future industrialization.

Good luck.

Breizh  

[golegolegole]

Haha, sure thing breizh. We all community members are really thankful to y'all for all the help you have provided to young engineers and also for sharing your valuable experience with us!

 

Hi,

My reply was based on 20 years' experience in batch process (latex, resins, API).

Nothing theoretical but from pilot studies where all the parameters are defined for future industrialization.

Good luck.

Breizh