×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Catalyst Mixer Temeperature Control

Catalyst Mixer Temeperature Control

Catalyst Mixer Temeperature Control

(OP)
Hi,
For preparing catalyst we are using a 7' ID by 9' T/T Carbon Steel mixing tank with agitator at around 30 % height of the vesssel from the bottom. Vessel is vertical. We are going to install temperature element to measure and control the fluid (mixed) temperature at 25 (±5) deg C. A 4" flange available on the head.
1- Do we need thermowell? or stilling well.
2- What type of sensor (RTD fast response or thermocouple)? and how many?
3- Should we look into multipoint temperature measurement for this 9' high vessel.
Any suggestion is appreciated. Thanks

RE: Catalyst Mixer Temeperature Control

The response speed depends on heat transfer from liquid to the RTD. There are layers of different materials that resist the transfer: a stagnant layer of the liquid around the well, the wall resistance of the well, resistance of the liquid or air in the well, the wall of the metal sheath around the sensor, the ceramics around final RTD winding or whatever.It is good practice to apply a thermowell from the side of the vessel:you can change the probe even if the vessel is full, it is mechanically protected and you can fit the material of the well if there is a problem with corrosion. For good dynamics you should provide good Reynolds number around the well.For good heat transfer the well should be filled with some liquid or grease with excellent heat transfer properties.When choosing the RTD look for the one with small time constant.With good aggitation temperature in the vessel will be more or less homogeniously distributed. With additional sensors you will be confused with differences in readings that cannot be assigned to real diferences in temperature. A volume of a liquid like that cannot change its temperature very quickly unless we talk about runaway or ...explosion.
M777182

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources