Separator and method

Claim 1

A device of claim 1, in which there is a second pressure sensor which senses pressure in the interior of the separator housing, but at a different point along the separator screw from the first pressure sensor, and the control is based on the difference in pressure between the two pressure sensors.

Claim 12

A device for separating materials comprising a separator screw, a housing surrounding that screw, an inlet in the housing at an intermediate point therein, a first outlet from the housing for some of what has been admitted, which first outlet is at a point in the direction of separator screw impulsion from the inlet, the interior of the housing including a chamber beyond the end of the separator screw in the direction opposite to that of separator screw impulsion, a second outlet from the housing, which second outlet is from this chamber, for some of the material which has been admitted to the housing, which second outlet is at least substantially beyond the end of the separator screw nearest to the chamber and in a direction from the inlet which is counter to the direction of screw impulsion, at least one stationary vane located in the chamber and extending substantially longitudinally relative to a direct line from the said nearest end of the separator screw to the second outlet from the housing, a feed-out screw housing receiving the material flowing from the first outlet, a feed-out screw in the feed-out screw housing and means for automatically and continuously turning the feed-out screw at a speed which will maintain a hold back pressure between the separator screw housing and the separator screw.

Claim 16

A device for separating materials comprising: a. a separator screw having an intermediate portion shaped as the frustum of a cone, a relatively large-diameter cylindrical portion at the large end of that intermediate portion, a relatively small-diameter cylindrical portion at the small end of that intermediate portion, and a shaft portion without screw beyond the end of the relatively large-diameter cylindrical portion from the intermediate portion, the pitch of the screw being smallest where the intermediate portion is smallest in diameter and being larger in the relatively small-diameter cylindrical portion and also increasingly larger in the other direction from its minimum point up to a point in the relatively large-diameter cylindrical portion; b. a separator housing surrounding the separator screw and having a relatively small-diameter cylindrical portion around the relatively small-diametered cylindrical screw, an intermediate portion shaped as a frustum of a cone around the intermediate screw portion, and a relatively large-diameter cylindrical portion around both the relatively large-diameter screw portion and the shaft portion beyond, extending to a distance beyond the relatively large-diameter screw portion which is approximately equal in length to that of the relatively large-diameter screw portion, and the housing including in it passages for heat transfer fluid connected to a source for such fluid and having two opposite longitudinal removable vanes extending inward from the portion around the shaft portion to just short of the shaft, so that a chamber is formed around the shaft which chamber is divided into two by these vanes, and there being an inlet for material to be separated which inlet is located at an intermediate point in the relatively large-diameter cylindrical portion, a first outlet for the component of the material which is more subject to screw impulsion which outlet is beyond the end of the screw at the small-diameter cylindrical portion end, and a second outlet for the component of the material which is less subject to screw impulsion which outlet is at the far end of the chamber from the inlet; c. a cylindrical pump-out screw which is longer and has a smaller helix angle than the small-diameter portion of the separator screw and is run at a slower rotational speed than the separator screw; d. a cylindrical pump-out housing surrounding the pump-out screw, having passages to receive heat transfer fluid from a source for such fluid, and having an inlet at its rear end connected to receive material from the first outlet of the separator screw and having an outlet at its forward end; and, e. a control system including pressure sensors at two different points, longitudinally speaking, in the interior surface of the intermediate portion of the separator housing, and a proportional controller actuated by the pressures thus secured controlling the particular speed of the pump-out screw.

Claim 17

A method of separating materials, comprising introducing the material to be separated into a housing surrounding a partly tapering separator screw at an intermediate point relative to the separator screw, operating the separator screw to tend to drive one of the materials in the direction of the small end of the taper and through an outlet from the housing beyond that small end to make the other of the materials proceed in the opposite direction and through an outlet toward that opposite end, pUmping the material from the outlet beyond the small end by means of a pumping screw located beyond the outlet, advancing the pumping screw so slowly as to maintain hold-back pressure around the separator screw, sensing the hold-back pressure in the partly tapering screw and controlling the speed of operation of the pumping screw on the basis of the pressure sensed.