Patent ID: 8453876
Filing Date: 2013-06-04
Classification: B01F,B44D

Abstract:
1. A dispense and recirculation valve assembly for a viscous slurry, the assembly comprising: a cylindrical tube comprising a proximal end and a distal end, the distal end connected to a nozzle, the proximal end connected to a stem seal, the tube further comprising a dispense inlet and a recirculation outlet disposed between the proximal and distal ends of the cylindrical tube, a valve stem passing through the stem seal and comprising a proximal end connected to an actuator disposed outside of the tube and a distal end comprising a lower conical valve element that narrows distally and widens proximally to a diameter that is greater than a diameter of the distal end of the valve stem, the valve stem further comprising an upper frustoconical valve element disposed proximally of the lower conical valve element, the nozzle comprising a dispense outlet and a lower frustoconical valve seat for receiving the lower conical valve element, the lower frustoconical valve seat narrowing distally and widening proximally, the lower conical valve seat being threadably connected to the distal end of the tube, the tube accommodating an upper frustoconical valve seat disposed between the dispense inlet and the recirculation outlet for receiving the upper frustoconical valve element, the upper frustoconical valve element and upper frustoconical valve seat both widen distally and narrow proximally, the valve stem being movable between a recirculate position and a dispense position, in the recirculate position, the lower conical valve element engages the lower frustoconical valve seat and passes partially through the lower frustoconical valve seat and partially through the dispense outlet, in the dispense position, the lower conical valve element is moved proximally away from the dispense outlet and lower frustoconical valve seat and into the tube and the upper valve element engages the upper valve seat, wherein the stem seal comprises a nut comprising a top wall with an opening for receiving the stem, the stem seal further comprising a threaded sidewall threadably connected to the proximal end of the tube, and the seal assembly further comprising a gasket trapped between the top wall of the nut and the proximal end of the cylindrical tube.