Background

There are three diesel fuel steam boilers in a sauce production plant. Boiler feed water is treated by water softener and chemicals.

In order to reduce the fuel cost, HydroFLOW is installed. The boiler tubes were inspected before the installation of HydroFLOW and shown in picture 1.

Result

After one year of operation without pre-cleaning of the tubes, it was found that the scale deposit on tubes was much thinner than one year ago as shown in picture 2. Moreover there was powder settled on the bottom of the boiler.

Without any guesstimation, sample was collected and sent to MRC of Hong Kong Polytechnic University for SEM/EDX analysis.

It was found that the major composition of the sample is calcium carbonate which is in a soft scale form, i.e. aragonite. This is the result of descalingwhen hard scale (calcite) is transformed into soft scale (aragonite).

As reported by the customer, the annual fuel consumption is cut by 10.0% and finally the installation of HydroFLOW can be paid back in 3 months.