Screening apparatus

A screening device for separating smaller and larger aggregate materials from a mixed aggregate stream flowing through the screening device from upstream to downstream by force of gravity, comprising:

• at least two decks, with an upper deck disposed upstream before a lower deck disposed downstream of the upper deck, each deck separately adjustable from about 10 to about 70 degrees, and each deck having a deck frame, the frame further divided into a grid with separate openings for receiving a panel therein, wherein each panel is either an impervious blank or a screen, the screens having openings therein to selectively permit smaller aggregate to pass through the screen thereunder, while the larger aggregates must pass over the screens;
• such that a path for the aggregate stream is provided over the upper deck before the lower deck so that when used smaller aggregate falls through the screens while the larger aggregate remains in the aggregate stream;
• adjacent flumes for affixing decks thereon, the flumes disposed along the pathway of the mixed aggregate stream from upstream to downstream;
• each flume having a bottom and opposing sides forming a pathway for the smaller aggregate between the bottom of the flumes and the decks;
• the adjacent flumes including a top flume disposed upstream for affixing the upper deck therein, and a bottom flume disposed downstream for affixing the lower deck therein;
• the top flume having a bottom, opposing sides, an upstream side, and a downstream side, the downstream side of the top flume having an opening therethrough for feeding the larger aggregates to the top of the deck of the adjacent flume;
• and a bottom with an opening under the downstream side for feeding the smaller aggregates to the bottom of the adjacent flume under the deck thereof;
• and
• the bottom flume having a bottom, opposing sides, an upstream side, and a downstream side;
• the upstream side of the bottom flume having an opening at the bottom of the adjacent flume to receive the smaller aggregates from the upstream adjacent flume and the downstream side having an opening adjacent the bottom of the bottom flume therethrough for discharging the larger aggregates;
• and the bottom of the bottom flume having an opening therethrough adjacent the downstream side of the bottom flume for discharging the smaller aggregates.

A method of using a screening device, comprising:

• feeding a mixed aggregate onto a screening device to separate the mixed aggregate into smaller and larger aggregate materials in which the aggregate stream flows through the screening device from upstream to downstream by force of gravity;
• screening the mixed aggregated by allowing the aggregate stream to flow over the screening device, in which the screening device has
• at least two decks, with an upper deck disposed upstream before a lower deck disposed downstream of the upper deck, each deck separately adjustable from about 10 to about 70 degrees, and each deck having a deck frame, the frame further divided into a grid with separate openings for receiving a panel therein, wherein each panel is either an impervious blank or a screen, the screens having openings therein to selectively permit smaller aggregate to pass through the screen thereunder, while the larger aggregates must pass over the screens;
• such that a path for the aggregate stream is provided over the upper deck before the lower deck so that when used smaller aggregate falls through the screens while the larger aggregate remains in the aggregate stream;
• adjacent flumes for affixing decks thereon, the flumes disposed along the pathway of the mixed aggregate stream from upstream to downstream;
• each flume having a bottom and opposing sides forming a pathway for the smaller aggregate between the bottom of the flumes and the decks;
• the adjacent flumes including a top flume disposed upstream for affixing the upper deck therein, and a bottom flume disposed downstream for affixing the lower deck therein;
• the top flume having a bottom, opposing sides, an upstream side, and a downstream side, the downstream side of the top flume having an opening therethrough for feeding the larger aggregates to the top of the deck of the adjacent flume;
• and a bottom with an opening under the downstream side for feeding the smaller aggregates to the bottom of the adjacent flume under the deck thereof;
• and
• the bottom flume having a bottom, opposing sides, an upstream side, and a downstream side;
• the upstream side of the bottom flume having an opening at the bottom of the adjacent flume to receive the smaller aggregates from the upstream adjacent flume and the downstream side having an opening adjacent the bottom of the bottom flume therethrough for discharging the larger aggregates;
• and the bottom of the bottom flume having an opening therethrough adjacent the downstream side of the bottom flume for discharging the smaller aggregates;
• and
• discharging the larger aggregates and the smaller aggregates into separate pathways.