MECHANICALLY OPERATING SCREENS

MECHANICALLY OPERATING SCREENS

A new storage reservoir for Newark, N. J., with a capacity of 100,000,000 gallons will be placed in service in August of this year. The reservoir is a mile long and an eighth of a mile wide, and, together with a 3,000-foot tunnel, an eight-mile pipe line and connections with city mains, will cost in round numbers $2,000,000. The outlet gate-chamber controling the flow of water to the city is located in the reservoir basin sixty-five feet from the shore and in a depth of fifty feet of water. In this chamber are four wells, each eight feet long and six feet wide, through which the water passes before entering the distribution system. In the two front wells are cast iron grooves, in which the screens slide. The frames for the screens, instead of being made of wood, as is customary, are two and one-half inch by two and one-half inch by three-eighth inch steel Tees bent to form a four-foot seven-inch square. On to this frame is riveted a sheet of No. 18 hard copper punched with five-sixteenth-inch holes, seven-sixteen inch on centres. At the centre top edge of each screen is attached a pair of sliding jaws, which are forced upwards by a stiff spiral spring converging as they rise. As the screens are placed one on top of the other, the jaws to each under screen are forced down and open by the weight of the screen above, so that, when the screens are all in place, all of the jaws arc down, except those on the top screen. The power transmission to raise and lower these screens is very simple. On a shaft twelve feet above the floor of the gatechamber are placed two sprocket wheels, one over each well in which the screens are located. Engaging these wheels is an endless sprocket-chain extending sixty feet down to idlers at the bottom of each well. Two special links or buttons one inch greater in width than the remaining links, are inserted diametrically opposite to each other in each chain. These chains pass through the jaws attached to each screen, and the jaws are so spaced that, when pressed down, both chain and button will pass through. When the jaws are released, however, only the chain can pass through them, and, hence, as the button comes up, it engages in the jaws of the top screen and raises this screen out of the well. Cams which hold the jaws together are then swung back; the jaws tire opened; ami the screen is released from the chain. It is then picked up by a differential chain-block and carried on an overhead track to the centre of the chamber, where it is washed and then cither returned to the well or stored in another part of the gate house. A four-horsepower, gasolene engine, with a friction-clutch attached to the pulley, furnishes the power, and a worm-wheel drive is used to transmit the power to the main shaft on which the sprocket wheels are placed. A shifting lever is used to throw the sprocket wheels into clutch with the main shaft, and a double beveled gearing is used to reverse the direction of the shaft. The screens are raised out of the wells at a rate of twenty feet per minute. So far the writer has not heard of any arrangement quite similar to the one described, and, while ⅛ has not as yet ln*en in actual operation under all conditions of service for which it is designed, the tests made up to the present time have been satisfactory.

The original design of this screen was prepared bv Carleton K. Davis and installed by the resident engineer under the direction of Morris R. Sherrerd, chief engineer.

SCREENS FOR OUTLET-CHAMBER, CEDAR GROVE RESERVOIR, NEWARK, N. J.
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