_O & M MANUAL - WEST LANE MOBILE HOME PARK

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When two feed tubes are active, they must be located in positions 2 and 3. The remaining two tubes are inverted and placed in positions 1 and 4. When three feed tubes are used, they are placed in ^� positions 1, 2, and 3 with the remaining tube inverted into position 4. When all four tubes are active, they are all charged with tablets and inserted in positions 1 through 4 with slotted ends down. Feed Tube Spacers You will note that each feeder is equipped with four (4) spacer disks. The spacers are constructed of grey PVC, having compatible dimensions to the tablets. The center holes will allow drainage of any trapped water. Their intended use is to serve as an "automatic" means to reduce the amount of chlorine being delivered. This is done by lifting (spacing) the active stack of tablets, in '/ " or '/4" increments, off the floor of the feeder -limiting the contact area between the incoming stream and the tablets. Prior to charging the feed tubes with tablets, the desired number of spacers should be placed in the tube. Care should be taken that the height of the total number of spacers used does not exceed the water level within the feeder housing. This will prevent contact of the stream with the active tablets. Laboratory data showed that one spacer reduced the ini- tial levels of chlorine by approximately 38% and two spacers provided 67% reduction in the initial concentra- tion. On -Stream Operation When the proper weir plate is in place and the feed tubes are charged and correctly positioned, the system is ready for operation. Admit the entire plant now of treated wastewater through the feeder ... operation is continuous and automatic. After the system has been in operation for approximately one hour, samples should be taken from the effluent end of the chlorine contact tank for chlorine residual analysis. Although the chlorine residual may be determined by a variety of test methods, the preferred and recommended method is the starch -iodide procedures described in the most recent approved edition of STANDARD METHODS FOR WATER AND WASTEWATER. Take several samples for chlorine analysis between the 11 first and second hours of operation. This will allow time for the chlorine residual to reach a state of equilibrium in the detention tank. When two or three chlorine residuals determined 15 minutes apart are consistent with each other, the system may be considered stable. Occasional samples taken in the same way may be used to check the chlorine delivery at any time. If the results of the chlorine residual testing, or any other test, indicate that the unit is not providing sufficient chlo- rine, the necessary adjustments may be made by chang- ing the weir size or feed lubes. (See TROUBLE SHOOT- ING.) If desired, bacteriological analysis for Escherichia Coli may be performed on the effluent from the detention tank. Optional analysis that may be run on the effluent are B.O.D., C.O.D., pH, suspended solids, nitrite, ammo- nia and dissolved oxygen. Tests for all these are described in STANDARD METHODS mentioned previ- ously. MAINTENANCE The Model 1000 or 1001 requires very little maintenance. Refilling of the feed tubes and an occasional on -stream cleaning of the feeder are the only maintenance proce- dures required. Refilling the tubes is done on a schedule based on plant flow and weir size as shown in Figure 9. The refill inter- vals are at the option of the operator as outlined under PREPARATION FOR OPERATION. The tubes should always be filled to the top. This assures the longest pos- sible periods of unattended operation. Occasional cleaning of the feeder to remove accumulat- ed residues may be required. This will depend on the quality of the influent passing though the unit. Usually, once every six to twelve weeks is sufficient. Solids accu- mulated around the feed tubes are removed by pulling the tubes a few inches off the bottom of the feeder and raising the weir plate to permit the water to rush out the exit end of the dissolver. This action, if repeated a few times, will flush out most solids. Fibrous materials may adhere occasionally to the bottom of the feed tubes. Removal of these with a rod or gloved hand, combined with the shearing force of channeled water in the feeder is sufficient to remove these materials. Once a year the feed tubes may require removal of inter- nal scale buildup by simply scraping the inside surfaces of the tubes.