We tend to experience fouling due to an accumulation of coke fines in our Tail Gas Scrubber after about a 3 year run. This becomes a rate limiter due to H2S spikes. We have a pallring packed tower and we do use antifoam to help curtail the foaming issue. In the past, we have tried to some success, closing the rich amine release control valve and filling the tower up into the pallrings then dumping to clear out the coke fines and have had some degree of sucess but this upsets the Sulfur Unit so we are now reluctant to do it this way. Are there any other cokers experiencing this problem and if so, what are you doing to correct it?