To provide a new system for controlling the flow of vapors sublimated from solids.
A vapor delivery system for delivering a steady flow of sublimated vapor 50 to a vacuum chamber 130 includes a vaporizer 28 of solid material 29, a mechanical throttle valve 100, and a pressure gauge 60, and a vapor conduit 32 communicating with the vacuum chamber. The vapor flow rate is determined by both the temperature of the vaporizer and the setting of the conductance of the mechanical throttle valve located between the vaporizer and the vacuum chamber. The temperature of the vaporizer is determined by closed-loop control 35 to a set-point temperature. The mechanical throttle valve is electrically controlled, and the valve position is under closed-loop control 120 to the output of the pressure gauge. The vapor flow rate can be proportional to the pressure gauge output. All surfaces 37 exposed to the vapor from the vaporizer to the vacuum chamber are heated to prevent condensation. A gate valve and a rotary butterfly valve can act as the throttle valve.
COPYRIGHT: (C)2010,JPO&INPIT
MILGATE ROBERT W III
| JPH04232275A | 1992-08-20 | |||
| JPH04232275A | 1992-08-20 |
JPN7012005004; Ｊ．Ｊ． ＳＵＬＬＩＶＡＮ ｅｔ ａｌ．: 'Ｍａｓｓ ｆｌｏｗ ｍｅａｓｕｒｅｍｅｎｔ ａｎｄ ｃｏｎｔｒｏｌ ｏｆ ｌｏｗ ｖａｐｏｒ ｐｒｅｓｓｕｒｅ ｓｏｕｒｃｅｓ' Ｊ． Ｖａｃ． Ｓｃｉ． Ｔｅｃｈｎｏｌ． Ａ ７（３）, 1989, ｐｐ． ２３８７-２３９２
Takaaki Yasumura
Natsuki Morishita
Next Patent: HARDMETAL COMPOSITION AND FABRICATION METHOD FOR HARDMETAL