Fig. 125.—“Coleman” Dosing Valve.
Messrs. George Kent, Ltd., have introduced several different types of dosing apparatus, which can be arranged to draw off less than 6 inches head of water and any greater depth. In one case the apparatus, [Fig. 127], consists essentially of a seating S, through which the liquid discharges, a valve-cap C, attached to arms which rotate about the pin P and nearly balanced by the weights W, also by floats F F attached to a frame, also rotating about P and carrying two adjusting weights A A. The apparatus is actuated by the rise of the liquid, raising the floats and lifting the cap C, which returns to its position after the discharge has taken place. For greater depths a different type is used, as shown in [Fig. 128]. In this case the apparatus consists of a valve seating S, through which the liquid discharges, two floats A and B, a controlled device for giving a sudden release and for regulating the levels at which the valve is opened or closed, and an alternating gear G, which is fitted with two or more valves placed in the chamber and operated in rotation. The action of the apparatus is as follows: When the liquid in the dosing chamber reaches the top level, the float A has acquired sufficient buoyancy to cause the shoulders of the plate K to suddenly push aside the rollers at the ends of the weighted levers L L of the control device. The lugs T T then come in contact with the collar R, and the valve-cap C and the float B are lifted. The tank discharges until the floats A and B have lost sufficient buoyancy to cause the bottom shoulders of the plate to push aside the rollers and allow the valve to close.
Fig. 126.—Dosing Valve.
Fig. 127.—Dosing Valve.