TM 5-4610-223-12
2-9) every 30 minutes. If the chlorine residual is less than that prescribed by the medical officer increase the calcium
hypochlorite solution rate of discharge. Move the feed indicator FEI-8 (2, fig. 2-5) to a higher scale (3) reading. Raider
Model only loosen thumbscrew (2, fig. 2-5.1) and rotate calcium hypochlorite control knob (6) to a higher stroke setting.
Retighten thumbscrew.
If the chlorine residue is greater than the required amount, decrease the calcium hypochlorite solution rate of
discharge. Move the feed indicator FFI-8 (2, fig. 2-5) to a lower scale (3) reading. Raider Model only loosen
thumbscrew (2, fig. 2-5.1) and rotate calcium hypochlorite control knob (6, fig. 2-5.1) to a lower stroke setting.
Retighten thumbscrew.
Use the calcium hypochlorite solution calibration chart (fig. 2-11) as an aid in determining the proper setting.
(g)
Increase filter run. To increase the length of the filter runs, increase the diatomaceous earth slurry rate of
discharge. Move the variator feed indicator FEI-5 (3, fig. 2-15) to a higher feeder scale reading. Use the diatomaceous
earth slurry calibration chart (fig. 2-25) as an aid in determining the proper setting.
(h)
Decrease filter run. To decrease the length of the filter runs, decrease the diatomaceous earth slurry rate of
discharge. Move the variator feed indicator FEI-5 (3, fig. 2-16) to a lower feeder scale reading. Use the diatomaceous
earth slurry calibration chart (fig. 2-25) as an aid in determining the proper setting.
(i)
Water has objectionable color, taste, or odor.
1.
If the water has an objectionable color, taste, or odor, add a base charge of 1/10 pound of activated
carbon per gallon of water to the limestone compartment of the slurry feeder.
2.
The limestone compartment holds approximately 14 gallons.
3.
Measure 1.4 pounds of activated carbon.
4.
Pour activated carbon into limestone compartment.
NOTE
The Raider Model 72-PVC Duplex chemical solution feeder control knob index marks do not
correspond to the abscissa of the calibration charts. The index marks relate to diaphragm pump
output capacity only (0-100%). Setting of the control knobs must be determined by analyzing the
treated water.
NOTE
Calibration charts (figs. 2-9, 2-11 and 2-12) are provided covering full range of feed for a raw water
flow of 3000 gph for each chemical feeder. The ordinate of each chart has 2 scales; one in ppm and
one in ml/min. The abscissa of each chart is in feeder scale readings. Each chart is identified as to
its respective feeder, slurry, and solution concentration, and flow rate. Curves are based on the
solution and slurry concentrations expressed in pounds of chemical per gallon of water as follows:
Change 4 2-54