Q & A > Question Details
Can anyone please tell me how to identify whether the liquid is forming a channel in the reactor packed bed?
Also please confirm the effect of pressure drop across the bed if channelling occur? will it increase or decrease?
In my understanding, the pressure drop will increase. But I need documents to support my argument.
Please help!
25/02/2018 A: Ganesh Maturu, Self, maturu.ganesh@gmail.com
Pressure drop increase due to channeling may not be necessary as HC and H2 passes through least resistance path and it can be created with same pressure drop after channeling. Channeling may be confirmed by checking radial temperature variations across reactor at various levels. If the temperature variation is more than 6-10 deg C, there is a channeling.
14/02/2018 A: Ralph Ragsdale, Ragsdale Refining Courses, ralph.ragsdale@att.net
On the question of “how to tell,” a well-designed pattern of radial bed thermocouples and the luck of having them read accurately throughout the run are the best means of determining channeling .
14/02/2018 A: Eric Vetters, ProCorr Consulting Services, ewvetters@yahoo.com
Channeling can either result in an increase in DP or a decrease in DP depending on what is causing it. If there is coking in the bed, then flow will be forced through paths that are not coked. The reduction in flow area will cause a net increase in DP. If there are voids in the catalyst bed due to poor loading of the catalyst into the reactor, then the void spaces in the bed provide more open channels for flow. Flow takes the path of least resistance and much of the catalyst bed is effectively bypassed.
If you have coking going on you will see a higher than expected reactor DP. It may or may not be accompanied by erratic radial temperature profiles and/or difficulty meeting product specs (if coking is uniform across the top of the bed then it may only show up as higher than expected DP). If you have channeling due to poor catalyst loading it will show up as lower than normal DP, difficulty meeting product sulfur specs, and likely an erratic radial temperature profile.