2Survey of Possible Flash Steam Applications

The process should be surveyed in detail to assess what applications presently using first-generation steam might be adaptable to the use of flash steam or to heat recovered from condensate. Temperatures and typical heat loads are necessary but not sufficient. Heat-transfer characteristics of the equipment itself may be important. A skilled heat-transfer engineer, given the present operating characteristics of a process heater can make reasonable estimates of that heater's capability to operate at a lower pressure.

3. Analysis of Condensate and Boiler Feedwater Chemistry. To assure that conditions in the boiler are kept in a satisfactory state to avoid scaling and corrosion, a change in feedwater treatment may be required when condensate is recovered and recycled. Water samples from the present condensate drain, from the boiler blow-down, from the incoming water source, and from the outlet of the present feedwater treatment system should be obtained. With this information, a water treatment specialist can analyze the overall water chemical balance and assure that the treatment system is properly configured to maintain good boiler-water conditions.

4. Piping Systems. A layout of the present steam and condensate piping system is needed to assess the need for new piping and the adequacy of existing runs. This permits the designer to select the best locations for flash tanks to minimize the need for extensive new piping.

5. Economic Data. The bottom line on any energy recovery project, including condensate recovery, is its profitability. In order to analyze the profitability of the system, it is necessary to estimate the quantity of heat recovered, converted into its equivalent fuel usage, the costs and cost savings associated with the water treatment system, and savings in water cost. In addition to the basic capital and installation costs of the condensate recovery equipment, there may be additional costs associated with modification of existing equipment to make it suitable for flash steam utilization, and there will almost certainly be a cost of lost production during installation and checkout of the new system.

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