Fred Marion Walker

US Patent:

50789228, Jan 7, 1992

Filed:

Oct 22, 1990

Appl. No.:

7/601270

Inventors:

Craig C. Collins - Santa Cruz CA
Michael A. Richie - Santa Cruz CA
Fred F. Walker - Santa Cruz CA
Brian C. Goodrich - Los Gatos CA
Lowell B. Campbell - Santa Cruz CA

Assignee:

Watkins-Johnson Company - Palo Alto CA

International Classification:

B01F 304

US Classification:

261139

Abstract:

An improved bubbler has walls formed of thin stainless steel. A hollow cylindrical body member forms a cylindrical sidewall and has welded to it a top end cap and a bottom end cap. A horizontally disposed sparger tube is connected to the carrier-gas inlet tube and is positioned within the bubbler chamber adjacent to the bottom end cap. The sparger tube has a plurality of horizontally spaced-apart exit holes formed therein for providing a plurality of carrier-gas streams into the liquid chemical. The carrier gas bubbles up through the liquid chemical, causing the liquid chemical to vaporize and diffuse into the carrier gas. A substantially uniform temperature throughout the chemical liquid is provided with a heat-conductive enclosure formed of aluminum plates which are thicker than the walls of the bubbler chamber and which contact and entirely surround the exterior surface of the stainless steel bubbler chamber. Heating and cooling means are also provided for controlling the temperature of the liquid chemical in the bubbler chamber at a predetermined temperature. The bubbler chamber includes additional features such as a dimple formed in the bottom end cap to prevent reflection of light from a laser liquid-level sensor unit.