|Sourcebook of Alternative Technologies for Freshwater Augmentation in Africa (UNEP-IETC, 1998, 182 p.)|
|Part C - Case studies|
The process involves the use of recycled water to blend with incoming cold water as feed water for boilers. Hot water obtained in the process is used in the brewing process or as a boiler feed water and filling pasteurizer. This technology is described in Part B, Chapter 3, "Mining and Industry."
Extent of Use
This technology is used in the brewing and bottling industry in Ghana, and specifically at the Achimota Brewery.
Operation and Maintenance
The regular maintenance of the mechanical systems is done by trained artisans employed by the Brewery.
Level of Involvement
The level of involvement is primarily within each factory and is, therefore, industry specific. Generally, the availability of trained artisans is the principal requirement for implementing this technology.
Initial capital costs may be high if plant operations need to be restructured and new equipment installed. However, these costs are usually offset by the long-term savings in water costs. No information on operating and maintenance costs is available, but the costs may be assumed to be reasonably low and similar to the cost of using conventional technologies.
This technology is suitable in any industry that demands a large volume of boiler water. The application used within the Brewery is similar to that applied to thermal power generation cooling systems (described in Part B, Chapter 3, "Mining and Industry").
Use of this technology, which can be easily integrated into the industrial process, results in a significant savings in both water demand and water costs in the industry. The technology also can be easily modified to include other sources of blending water such as groundwater.
Use of this technology is limited in application to situations where there are heat exchangers. Also, impurities within the blended water stream may result in boiler scale.
Further Development of the Technology
This is a fairly old technology. Current research is focusing more on improving the efficiency of the boilers rather than on the degree of recycling.
Achimota Brewery Limited, Achimota, Accra, Ghana.