Abstract: A shale shaker has been developed which, in one aspect, has one or more upper screens and one or more lower screens with an upper screen at a discharge end of the shale shaker and a lower screen disposed to receive material discharged from a discharge end of one of the upper screens. In one aspect a portion of a lower screen underlies the discharge end of the upper screen. In another aspect a solid flowback pan prevents material falling through the upper screen(s) from falling onto the lower screen(s); and, in another aspect, the pan prevents material on a top of the lower screen(s) from falling into a bottom sump of the shale shaker which receives material which has fallen through the screen(s).

Abstract: Screens have been developed which, in one aspect, have interconnection apparatus including male projections on one first screen end which are received in female openings on another adjacent screen end. In one aspect the female openings are defined by raised portions of a three-dimensional screen and the male projections either are formed of the other screen's end or are part of plugs inserted into raised portions of the first screen end. A shale shaker has been developed with such screens. In one aspect such a shale shaker has screens disposed in a tiered configuration, one screen in sealing contact with the next. Screen connector apparatus has also been developed for such screens.

Abstract: A vibratable shale shaker screen is disclosed which in one aspect, has a frame, screening material secured over the frame, and one or more sealing members secured to the frame for sealingly contacting an adjacent frame and/or adjacent portions of the frame or of screen mounting apparatus such as mount channels on the frame. Alternatively, sealing elements are provided on screen mounting apparatus, e.g. channels, on a shale shaker. A shale shaker is disclosed with at least one such screen. In one aspect such a shale shaker has three such screens disposed in a tiered configuration, one screen in sealing contact with the next. Adjustable screen mounts are disclosed for releasably holding the screens in sealing contact with each other and with screen mounting apparatus.

Abstract: A grid structure and screen device including the grid structure are provided for a vibrating shaker for filtering solids out of a moving fluid stream passing across this screen device. The grid structure has openings defined by intersecting lines of substantially continuous solid grid lines forming an angle. The angle formed at the intersection being from between less than 90.degree. and more than 0.degree., such that the grid structure fatigued resistance is enhanced while providing maximum open area therethrough.

Abstract: Devices and method are disclosed for opening, e.g. by puncturing, sealed containers of materials, e.g. drums filled with toxic or hazardous substances. In one aspect a support cradle supports one or more containers and is movable to dump their contents into a discharge hopper. In one aspect containers are punctured or opened by movable spears or cutters which are movable to open the containers, preferably with personnel spaced apart from or remote from the apparatus during operation. A variety of spray devices or nozzles may be used to create fogs or protective fluid sheets or films over or about various parts of the apparatus to inhibit unwanted dispersion of material in the containers.