The problem of blocked regenerators is not new in the glass industry, in fact it has been accommodated in regenerator design over many years by building the passage dimensions fairly large and by building more of them than necessary to permit the flow of gases under natural draught conditions.
It was generally understood that a regenerator was built twice the size necessary so that, as it gradually became blocked, the furnace would continue to function. The principal cause of regenerator blockage is the condensation of sulphates in the checker work.
The sulphates either come from the fuel, batch or additives to help melting the glass. The carry over from batch materials are also responsible for regenerator blockage. These materials have much higher melting points and are much difficult to remove by thermal cleaning. However, in most cases batch particles are stuck to the sulphates and will run down the regenerator once these start melting.
