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The main column of the FCM is three pieces of 2" white PVC pipe connected with 4 cm PVC connectors. The bottom segment is 18 cm long, the middle segment is 41 cm, and the top segment is 25 cm. The stock bottles are a 4 L bottle for the raw water suspension and a 1 L bottle for the alum solution. Hose ring clamps on the bottles are also clamped around thin stainless steel strips clamped to the PVC, wchich attaches the bottles to the column securely. The level control bottles are clear plastic peanut butter jars connected to the middle segment of the PVC pipe in the same manner. (All bottle and jar lids are kept loose or off while the plant is running.) These jars have two holes in them, the top one of which is the inflow, with a float valve to control the water inflow and keep the level constant, and the bottom of which is the effluent. For the clay jar, the effluent is connected to the inflow column for the flocculator via 0.17" i.d. transparent plastic tubing. The alum jar is connected with 0.063" i.d. transparent plastic tubing. The inflow column is a 25 cm long 1" clear PVC pipe plugged on the bottom with a plastic cap. There are two sets of holes drilled on the front half of the top section of the pipe, each to fit one of the tubes from the clay and alum jars. There are 5 of the holes for the larger tube, and they are spaced with 2 cm between the centers of the holes. There are 8 of the smaller holes, and they are spaced with 1 cm between the centers of the holes. The cap on the bottom of this column has a hole drilled into in it. A plastic tube connection is glued into the hole, into which a piece of 0.17" i.d. clear plastic tube is connected. This tube is inserted into the first channel of the flocculator.
Figure 1. Demo plant flow control module
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