We are writing from Colombian Sugar Factory. First of all this is important because in the sugar factory the steam demand is variable, due to there are many crushing cane stops in the daily crushing, that change the steam demand, besides the equipments factory changes its operation state.
 
We are having big problems for boilers?s solids carryover in the steam. This problem generate valves/Globe Valves jam in the turbogenerator.  Many months ago, we are taking correctives actions, like that:
 
Decrease the level in the steam drum. Before we are working with 50% like normal level, now is 40%.
We are working to feed the Caustic Soda (NaOH) directly to the drum, becaus now is feed in the feed water piping to the boilers.
 
The chemical treatement for the boliers is: Caustic Soda for pH regulation,  phosphate for the hardness, and sulphite for the oxigen, and polymer for Iron. The treatment is controled by NALCO.
 
Now, we would like to know the solutions possible for the steam boilers carryover.

The first possible cause is a higher than indicated drum water level. If the drum water level gauges are not temperature or pressure compensated. then the apparent level was not corrected for the true level. Related to this is the need for one of the level gauge legs to remain un-insulated.

The second possible cause is the steam loading of teh driers is higher than they were designed for. The driers were probably sized for max steam flow at full drum pressure, and if you are operating at less than full drum pressure at full steam flow then you will overload the driers. The boiler mfr should have provided a curve of max permitted steam flow vs drum pressure, based on this limitation.

The third possibility is that there is mechanical fault in the way the seperators were mounted or the driers were mounted. During the next outage, inspect the drum internals to ensure that there are no unsealed gaps between the centrifugal separators and the girth baffle plate, and that all driers aremounted securely.

A fourth possibility is that the boiler mfr did not know what he was doing and did not size or the drum internals correctly. You can sometimes fix this problem by retrofitting the driers with drainable driers or using a SS mesh pad in lieu of chevron driers.

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