The Protection of Boilers from Sugar

Sugar contamination of boiler feedwater by smallcontinuous traces is not as serious as that from large 'slugs' which frequently find their way into the boilers. Reference is made to several incidents of sugar contamination in boilers to showthat the most commoncauses are a malfunction of the feedwater system or its mismanagement, and to show that the method of sugar detection is seldom at fault. Some of the devices for detecting sugartraces in use or proposed are mentioned and their relative merits are discussed. In particular, the apparatus which was recently evaluated at the Sugar Milling Research Insitute(SMRI) is discussed in some detailand test results aregiven. The apparatuswas designed to measure the change in pH and conductivity of a condensate after being heated to 265°Cfor a few minutes. Suggestions are given on the typeof monitor to be usedin rawand refined sugar operations, the design and operation of the condensate handling system, and the options available for the future. It is concluded that, subject to some important precautions, the conductivity monitoring method is satisfactory for protecting boilers in a raw sugar mill against catastrophic failure.