Screen assembly

A screen assembly for grading and dewatering sand comprising a frame upon which is mounted a deck having a plurality of apertures therein, the frame being mounted on a base and being provided with a vibration generating device for imparting vibration to the deck, wherein the deck comprises a first portion inclined downwardly from a first end to a second end for grading sand thereon, and a second portion for dewatering sand thereon, wherein the frame comprises a pair of substantially parallel side walls between which the deck is mounted, and wherein each side wall is formed from a plurality of parallel plates comprising an outer plate, and inner plate and at least one intermediate plate, the intermediate plate having cut-outs formed therein to define a plurality of elongate reinforcing ribs, wherein the first portion of the deck is inclined downwardly at a first angle to the horizontal with respect to the normal direction of travel of material on the deck and the second portion being arranged substantially horizontally or inclined upwardly at a second angle to the horizontal with respect to the normal direction of travel of material on the deck wherein, in use, sand may be delivered onto the deck at or adjacent the first end of the first portion, undersized particles of sand passing through the apertures in the first portion of the deck as oversized particles are conveyed over the first portion of the deck under the action of gravity before passing onto the second portion of the deck, whereby the oversized particles are dewatered.

A screen assembly for grading and dewatering sand, the screen assembly comprising:

• a frame;
• a deck mounted on the frame, the deck having a plurality of apertures therein, wherein the deck comprises a first portion for grading the sand and a second portion for dewatering the sand;
• a vibration generating device operable to impart vibration to the deck;
• the first portion of the deck being inclined downwardly from a first end to a second end, wherein the first portion of the deck is inclined downwardly at a first angle to the horizontal with respect to the normal direction of travel of material on the deck;
• the second portion of the deck being inclined upwardly at a second angle to the horizontal with respect to the normal direction of travel of material on the deck;
• wherein the length of the first portion of the deck is greater than the length of the second portion of the deck;
• and
• wherein the deck is configured so that when sand is delivered onto the deck at or adjacent the first end of the first portion, undersized particles of sand passing through the apertures in the first portion of the deck as oversized particles are conveyed over the first portion of the deck under the action of gravity before passing onto the second portion of the deck, whereby the oversized particles are dewatered.