Water Treatment Chemicals For Cooling Towers And Boilers-candy boy

Business The first documented major outbreak of Legionnaires Disease in the UK occurred when twelve patients at Kingston Hospital contracted the disease in 1979. Detective work by the hospitals Engineer and Microbiologist eventually traced Legionella to the cooling tower, which was located opposite the main intake for the air conditioning system. The aerosol from the cooling tower, which contained the bacterium, was drawn into the air handling units and distributed around the hospital, exposing sick people who were susceptible to infection. These days, the microbiology of legionellosis is well known to every maintenance engineer, as are the means of preventing the spread of the pneumonia-like diseases by controlling bacteria like L pneumophila, L micdadei and L feelei. Good housekeeping and water management are the keys, together with compliance with the Health & Safety Executives Approved Code of Practice L8. Any water system which could potentially generate an aerosol is at risk, and that includes hot and cold down services fitted with spray taps or showers as well as humidification systems, cooling towers and industrial sprays. Good system housekeeping starts with good design. Legionella proliferates at temperatures between 20? and 45?C and prefers stagnant areas protected by scale deposits and corrosion products, which is, of course, why it finds cooling towers such an ideal environment. Operating outside this temperature range minimises growth, so keeping cold down services cold and hot down services hot is a good means of control. Building services engineers should pay particular attention to separating hot and cold water pipes, providing lagging where necessary, and to avoiding dead legs in pipes and stagnant areas in storage tanks. Once the system is installed and operating, the first pre-requisite is to ensure its clean. This can be achieved effectively through the use of water treatment chemicals. This may be simply a matter of disinfection, but badly corroded or scaled systems may need extensive chemical cleaning prior to disinfection to ensure that the disinfectant actually reaches the places where bacteria breed. The selection of the water treatment chemicals will, of course, depend on the nature of the deposit to be removed so it is essential to take samples of the deposits for analysis, careful monitoring of the water chemical treatment process is vital, as is careful attention to safety legislation like COSHH. Once the system is clean it has to be maintained in that condition, both by scheduled cleaning and disinfection, and by control of the chemical and microbiological conditions. This means the judicious use of corrosion inhibitors, scale inhibitors, dispersants and biocides. Once again the choice of water treatment chemical and its correct control is critical to success. But chemical treatment alone is often not the best way to manage water. Cooling tower blowdown controls the concentration factor. The higher the concentration factor the lower the blowdown. Blowdown water contains the expensive water treatment chemicals which have been added to condition the circulating water, so pre-treating make-up water, by ion exchange softening or dealkalisation or even reverse osmosis, to maximise the concentration factor is often cost effective. The addition of a side stream filter to remove suspended solids from circulating cooling water reduces the amount of sludge in the system and this reduces the amount of dispersat needed. The Guide to L8 shows that getting the chemistry and microbiology right is only the first step. Much of the Approved Code Of Practice is concerned with documentation: risk assessment, inspections, monitoring, control, Legionella testing and corrective actions all have to be recorded. Effective water treatment Systems can save money and reduce maintenance downtime. For More Information Visit: ..elgaprocesswater.co.uk/en/ About the Author: 相关的主题文章: