Organic Removal Cartridge

Figure 2-20.—Demineralizer. The inlet supply valve to the demineralizer must be adjusted on system start-up and periodically there- after to maintain the correct flow rate through the flowmeter. Too high a flow rate can damage the car- tridges. If the flow rate cannot be increased to the proper rate with the inlet supply valve fully open, you should check to ensure that the outlet valve is filly open. The submicron filter is used to remove small particles that have a size greater than 0.5 micron from the coolant flow. If the filter becomes clogged, it also reduces the flow of coolant, which necessitates a change of the filter cartridge or filter sheet (the mem- brane). To change the filter, you must properly posi- tion the demineralizer valves. If the filter cartridge or the membrane continually becomes clogged (about 1/2 hour or less after replacement), the usual cause in the distilled-water system is the presence of bacterio- logical impurities. Bacteriological impurities intro- duced into the secondary liquid-cooling system using distilled water may exist in the demineralizer car- tridges and/or the whole secondary cooling system. If the impurities are in the whole secondary cooling sys- tem, the growth rate in a warmwater environment could be of a magnitude that exceeds the capability of the demineralizer. In that case, you must determine the source and magnitude of contamination. However, bacteriological contamination in a secondary cooling system that uses distilled water and ethylene glycol is highly improbable. Improper handling or storage of the cartridges could cause them to be a source of contamination. Therefore, you should always store the cartridges in a cool, dry area, as exposure to heat hastens the growth of any biological contaminates that may have entered the cartridges. The three types of cartridges are or- ganic removal, oxygen removal, and mixed bed. Organic Removal Cartridge: The organic re- moval cartridge, which contains granulated activated charcoal (carbon) to remove large organic molecules and chlorine by adsorption, is always installed in the first exchanger (if required) to prevent organic mole- cules from fouling the remaining cartridges. 2-21