May 2007

Special Report: Maintenance/Reliability

How FCCU trickle valves affect catalyst losses

Here are the fundamental forces that affect their operation and the pros and cons of various types

Shaw, D. F., Walter, R. E., Carmagen Engineering, Inc.

High catalyst losses from fluid catalytic cracking unit (FCCU) cyclone systems are sometimes attributed to plugged diplegs, often believed to be caused by one or more malfunctioning trickle valves. Sometimes units are shut down and catalyst unloaded to "clear" a plugged dipleg. This article reviews the fundamental forces that affect trickle valve opening and closing for both positive- and negative-pressure cyclones. These forces are caused by the particular trickle valve design details, weight of the flapper or counterweight and catalyst level in the dipleg. The features of various trickle valve configurations will also be discussed, including the advantages and disadvantages for various a

Log in to view this article.

Not Yet A Subscriber? Here are Your Options.

1) Start a FREE TRIAL SUBSCRIPTION and gain access to all articles in the current issue of Hydrocarbon Processing magazine.

2) SUBSCRIBE to Hydrocarbon Processing magazine in print or digital format and gain ACCESS to the current issue as well as to 3 articles from the HP archives per month. $409 for an annual subscription*.

3) Start a FULL ACCESS PLAN SUBSCRIPTION and regain ACCESS to this article, the current issue, all past issues in the HP Archive, the HP Process Handbooks, HP Market Data, and more. $1,995 for an annual subscription.  For information about group rates or multi-year terms, contact email Peter Ramsay or call +44 20 3409 2240*.

*Access will be granted the next business day.

Related Articles

From the Archive



{{ error }}
{{ comment.comment.Name }} • {{ comment.timeAgo }}
{{ comment.comment.Text }}