Automatic metering of chemicals into swimming pools - with analysis of a mixed sample and using results to control chemical input

摘要

In automatic metering of chemicals into swimming baths, water is withdrawn continuously from the bath and recycled to the bath after metering in the required chemicals. Samples are withdrawn continuously of the outlet and input streams and these are mixed in a controlled ratio in a mixer unit. Measurements (esp. Cl content and pH) are made on the mixed sample and the resulting readings are used to automatically control the input of chemicals such as chlorine bleach liquor and HCl or CO2 into the recirculating water stream. Process gives continuous, service-free monitoring of swimming pool water and maintains correct chlorine level and pH with very low lag times (e.g. a few secs) c.f. 1-10 hrs. for previous systems.