Boiler water treatment is not generally viewed as an area with potential savings, but it should be on any site where steam is generated for the transfer of heat.
Traditional forms of treatment involve the use of dissolved salts (such as phosphates and sulphites) to protect the boilers from internal scaling and corrosion. A major drawback to these products is that, as salts, they affect the TDS (total dissolved solids) level in boiler and become part of what has to be removed from the boiler by blowdown. Any reduction in blowdown, while at the same time maintaining good boiler operation, leads to immediate energy savings.
GEMchem uses highly effective products that are true liquids and hence contain no dissolved salts. The addition of these products has no effect on the TDS in the boiler and the only constituents that need to be removed by blowdown are the salts occurring naturally in the local water (for example, calcium and magnesium bicarbonates). When the make-up water is softened through a base-exchange unit, the reduction in blowdown due to GEMchem products is 10% to15%. If the make-up water has passed through reverse osmosis or a demineralised plant, then the reduction is more like 90%. All this amounts to an appreciable reduction in energy consumption and the consequent direct and indirect financial savings.
Further savings are made on the heat transfer between the heat exchanger surfaces where the steam delivers the necessary temperature increase. Condensate drop formation is enhanced and this causes improved contact between the steam and the heat exchanger surface resulting in greater thermal efficiencies.
Another major consideration is the loosening of existing scale on the water-side of boiler tubes (frequently, calcium phosphate as a consequence of ineffectual previous phosphate based treatments). The old scale is encouraged to crack and fall off the boiler tubes.
