The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 07, 1999
Filed:
Aug. 11, 1997
Alex Wormser, Marblehead, MA (US);
Wormser Systems, Inc., Salem, MA (US);
Abstract
An enclosed-rotor vertical-shaft rotary valve is used as an airlock to inject abrasive, fine, or sticky solids into pressurized air. The invention eliminates the effect of thermal expansion on the gap between the rotor and casing, thereby making it possible to obtain much smaller gaps than before. The smallness of the gaps makes it feasible to pump clean air into the gaps without interfering with the performance of the airlock. The clean air keeps dust-laden air from entering the gaps, which eliminates the erosion that has limited the usefulness of conventional rotary valves when handling abrasive powders. By the use of two vents and a dual-pressure purge-air system, the invention also greatly reduces the blowby of air into the entrance of the airlock, which has limited the usefulness of conventional rotary valves when handling very-small-particle powders. These benefits also accrue to the injection of sticky solids into pressurized fluids. The invention extends the pressure and temperature capability of airlocks, so they may be used to inject solids into fluids at lower instead of higher pressure and so they may be used with fluids other than air.