DP Across Cold heat exchanger is increasing. Possibilities of Online cleaning

[sasicoro]

Hello all.,

Good day.,
Iam Working in a fertilizer manufacturing site. We have a sulphuric acid producing plant( raw material for Fertilizer). It is a Double conversion and double absorbtion process designed by Nicco Engineering in 1996.
We completed our shutdown activities last April 2016 and started the plant in the month of May 2016.
However the DP across the cold heat exchanger ( Both shell and Tube side has So2 and SO3 gas of varying mixture and at different temperature) has gone up in the past 2 month against the design of 270mmWc to 1300 mmwc.
This has reduced our throughput from 400 MTD to 350 MTD.
Request you to provide suggestion on
1. How to reduce the DP without going for a cold shutdown.?
2. What could be the possible reason for such a increase in Differential pressure?

 

[EdStainless]

Was it in this condition before your last turnaround? Did you clean it then?
What is the material of construction?
Are you sure that it isn't leaking?

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P.E. Metallurgy, Plymouth Tube

 

[sasicoro]

Yes we usually do mechanical cleaning during our Shutdown period.
Before cleaning - DP around 850mmWC
Material of construction in Carbon steel.
As of now no symptoms for tube leak. Rest of the process parameter remains constant.