Dosing Options
BCP® 5000 products can be added to geothermal power plant cooling systems as slug doses, or continuously.
Clean-up program dosing is always by slug dose, as it is desirable at the beginning of a clean-up program to establish a high concentration of the product in the recirculating cooling water in order to initiate deposit disaggregation.
Maintenance program dosing is usually conducted by slug dosing at reduced frequency and concentration compared to clean-up program dosing, but may be applied continuously if experience indicates the rate of refouling in a particular plant is low.
The timing and location of BCP 5000 product dosing must be coordinated with the dosing programs for all other water treatment chemicals, including biocides and cooling water pH adjustment chemicals. The optimal dosing strategy is plant specific, and must be developed over time as operating experience is gained.
Clean-Up Dosing to Remove Sulfur Deposits from Fouled Systems
BCP 5000 products are dosed once to twice per day during the initial phase of the clean-up program. Dosing should be at a concentration of 50 to 200 ppm of BCP 5030 (or equivalent) based on total cooling system volume. Once initiation of sulfur deposit removal is evident from monitoring program data, dosing can usually be reduced in concentration and/or frequency by approximately 25% to 50%, depending on refouling rate, for the remainder of the clean-up program.
Maintenance Dosing to Prevent Sulfur Deposition in Clean Systems
Systems which have been cleaned online with BCP 5000 products, or which have been mechanically cleaned during system shut-down can be maintained free of sulfur deposits by regular treatment with BCP 5000 products. Treatments can be applied either as periodic low concentration slug doses, or as a continuous lower concentration dose. Site-specific factors will
determine which mode of dosing will be most cost-effective for each plant.
Initial recommended maintenance treatments for slug dosing are 25 ppm (based on system volume), 3x per week. Initial recommended maintenance treatment for continuous dosing is 10 ppm (based on system blowdown). These two treatment approaches use approximately equivalent amounts of chemical for a system blowing down 4% to 5% of the system volume per hour. Effective monitoring will determine if these maintenance treatment levels are sufficient, more than required, or insufficient to prevent sulfur deposition in your system.
Contact AMSA to discuss optimal maintenance dosing for your system.
For more information on BCP 5000 product dosing, see the full BCP 5000 Series – Application Guide document.
