A mixing apparatus for mixing particulate material is described in which a plurality of different shaped blades are employed for thorough rapid mixing as the material moves downward through a mixing chamber and for impelling the mixed material downward through a discharge opening at the bottom of such chamber. A pair of convoluted lower mixing blades, which spiral downward and inward, are used to mix, to impel the material downward through the discharge opening, and to scrape such material from the conical bottom surface of the mixing chamber. First and second pairs of longitudinal intermediate mixing blades of different lengths positioned above the convoluted blades mix and scrape the material from the cylindrical side surface of the mixing chamber. A plurality of upper deflector blades are attached to the periphery of an upper baffle plate to deflect the material downward after it is thrown outward from the rotating baffle plate when the material is fed onto such baffle plate through the inlet openings of the mixing apparatus. A pair of separate screw conveyor feeding means are employed to transmit two different materials separately into the mixing chamber. For example, a first material consisting of sand and resin binder and a second material consisting of sand and catalyst for cold setting such binder are fed through two inlet openings in the top of the mixing apparatus which discharge the mixed material into boxes for making molds and cores used in metal casting.

A filtration system for removing both large, bulky and small, compactible solid contaminants from a liquid, intended primarily for the collection of chips and purifying and recycling coolant liquids used in machining and other metal working operations. Contaminanted liquid which has been used in the machining operation transports metal chips and other contaminants to a tank divided into upper and lower compartments by a wedgewire strainer. The sub-atmospheric pressure which develops in the lower compartment due to pumping of clean liquid from the lower compartment and the build-up of small, compactible contaminants on the upper side of the strainer is measured and a signal commensurate with the magnitude of the pressure provides the input to a drive motor for a continuous loop drag conveyor which scrapes the chips and sludge from the surface of the strainer. Thus, the rate of chip and sludge removal and the degree of coolant clarity is continuously and directly proportional to the degree of contaminant build-up. Also, the input signal to the drive motor has a minimum value greater than zero which is established as a function of the volumetric rate at which large, bulky contaminants, such as curly metal trunings, are supplied to the upper compartment. Although these contaminants provide very little resistance to flow through the strainer, they are nonetheless removed from the tank even at times when little or no small, compactible contaminants are present to increase the pressure differential between the upper and lower compartments.

Apparatus for relieving blockage of the pulp discharge passage in a cyclone separator included in a pulping system. The pulp stock is treated in an environment of superatmospheric steam and discharged together with the steam into the separator cyclone. The separated processing steam is evacuated from the cyclone while the steam liberated pulp stock is propelled through a throat which tapers towards the discharge valve by a screw conveyor whose flights are contoured to rotate snugly within the tapered throat. The discharge valve is controlled to maintain a predetermined rate of discharge and a predetermined superatmospheric pressure within the cyclone to allow evacuation of steam therefrom. The shaft of the screw conveyor is reciprocally mounted in the cyclone to allow the screw flights to yield in response to a predetermined excessive thrust resulting from compacted pulp stock blocking the throat, to provide a by-pass between the screw flights and the throat wall and thereby relieve the blockage. The invention may also include sensor means for controlling the rate of discharge in response to variations in thrust on the compacted pulp stock by the screw conveyor.

A system for producing gluten continuously at a rapid rate, the system including a vertical tube having an inlet at its upper end to receive a flour paste, the lower end of the tube being perforated to define a separation zone surrounded by a water jacket. A rotating shaft coaxially disposed in the tube acts to drive a conveyor screw within the separation zone, the screw having nozzles therein to eject water toward the inner wall of the tube. Keyed to the shaft is a main screw that is spaced from the extruder screw to define a collection zone therebetween, the main screw acting to work the paste fed into the inlet to produce dough which is discharged into the collection zone where it is picked up by the conveyor screw and advanced through the separation zone as a thin dough coil on the inner wall of the tube where it is subjected on one face to water jets from the perforations and on the opposite face to water ejected from the nozzles, thereby dissolving the starch and other soluble components of the dough to produce a milky liquid. The resultant slurry of the gluten and the milky liquid is deposited on a filter to extract the gluten.

Mixing apparatus comprising a vessel having a centrally disposed vertical draft tube and a centrifugal impeller at the lower end of the draft tube. A plurality of vertical heat exchanger tubes surround the draft tube. Ports are provided for the inlet of raw material and the outlet of product. The impeller draws liquid down through the draft tube, mixes it in an area of turbulence below the impeller and forces it up the heat exchanger tubes. Materials react in the heat exchanger tubes as in a plug flow reactor and elsewhere in the vessel the liquids mix and react as in a back mix reactor. The equipment is usable for continuous as well as batch operations.