PROPER ALKALINITY CONTROL – A KEY FACTOR IN LONG TERM SUCCESSFUL OPERATION OF A HIGH PRESSURE REFINERY WASTE HEAT BOILER

摘要

Failure to specify the proper control level of hydrate alkalinity in high pressure industrial boilers has resulted, over the years, in a myriad of problems. In the 1980s, the authors encountered a high heat flux, moderately high pressure, “process-on-the-tube-side” heat recovery boiler in a west coast oil refinery that had experienced two failures in quick succession. Several different mechanisms had been proposed to explain the failures. Caustic gouging was strongly suspected in the case of the first failure. While reviewing the available literature during the process of formulating an internal chemical treatment program and control regime, the authors uncovered a particularly compelling previously published paper that appeared to have been largely forgotten by the industry. This work was used as the basis for specifying hydrate alkalinity control in this system, with great long term success.