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1. (WO1979000957) ELECTRIC HEATER ASSEMBLY FOR DIFFUSION PUMPS
Latest bibliographic data on file with the International Bureau

Pub. No.: WO/1979/000957 International Application No.: PCT/US1979/000218
Publication Date: 15.11.1979 International Filing Date: 09.04.1979
IPC:
F04F 9/00 (2006.01) ,H05B 3/82 (2006.01)
F MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
04
POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
F
PUMPING OF FLUID BY DIRECT CONTACT OF ANOTHER FLUID OR BY USING INERTIA OF FLUID TO BE PUMPED; SIPHONS
9
Diffusion pumps
H ELECTRICITY
05
ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
B
ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR
3
Ohmic-resistance heating
78
Heating arrangements specially adapted for immersion heating
82
Fixedly-mounted immersion heaters
Applicants:
Inventors:
Priority Data:
89856721.04.1978US
Title (EN) ELECTRIC HEATER ASSEMBLY FOR DIFFUSION PUMPS
(FR) ENSEMBLE DE CHAUFFAGE ELECTRIQUE POUR POMPES A DIFFUSION
Abstract:
(EN) A diffusion pump includes a flat metal boiler plate (13) having an upper face (14) defining a floor for a pool of a vaporizable diffusion pump fluid or oil and a flat lower face (16) against which the metallic sheath (33) of a tubular electric heater (17) is pressed by a coextensive massive clamping plate (19). The heater (17) has a tendency to be overheated if only air is its thermal load. To prevent overheating of the heater (17) because of variations in the geometry of the heater sheath (33) which tend to cause air spaces between the sheath (33) and the face (16) of the boiler plate (13), a thin flexible metal crush plate (18) is disposed between the clamping plate (19) and the heater. The crash plate (18) has a plurality of spaced, raised dimples (37) adapted to contact many portions of the heater sheath (33) throughout the length of the sheath. As the clamping plate (19), the crush plate (18) and the heater (17) are urged toward the boiler plate (13) by nut and bolt assemblies (20, 21), the dimples (37) are deformed wherever they are in contact with the heater sheath. The deformed dimples (37) urge virtually the entire length of the sheath (33) into contact with the face (16) of the boiler plate and insure that pressure is applied to the heater sheath at the points of contact. Since there are many points of contact, the occurrence of local overheating, i.e., hot spots, is virtually eliminated.
(FR) Une pompe a diffusion comprend une plaque de chaudiere metallique plate (13) ayant une face superieure (14) definissant le fond d"un bassin de fluide ou huile vaporisable d"une pompe a diffusion et une face inferieure plate (16) contre laquelle la gaine metallique (33) d"un appareil de chauffage electrique tubulaire (17) est comprimee par une plaque massive de fixation, de meme etendue, (19). Le dispositif de chauffage (17) a tendance a surchauffer si l"air seul constitue sa charge thermique. Pour eviter le surchauffage du dispositif (17) du aux variations de geometrie de la gaine (33) qui a tendance a laisser des espaces d"air entre la gaine (33) et la face (16) de la plaque de chaudiere (13), une plaque metallique, mince et flexible, d"ecrasement (18) est disposee entre la plaque de fixation (19) et le rechauffeur. La plaque d"ecrasement ( 18) possede une pluralite d"ondulations espacees (37) qui sont adaptees pour etre en contact en de nombreux points de la gaine (33) sur toute la longueur de cette derniere. De meme que pour la plaque de fixation (19), la plaque d"ecrasement (18) et le dispositif de chauffage (17) sont presses contre la plaque de chaudiere (13) par des assemblages a boulons et ecrous (20, 21), et les ondulations (37) sont deformees partout ou elles sont en contact avec la gaine (33). Les ondulations deformees (37) poussent la gaine (33) pratiquement sur toute son etendue en la mettant en contact avec la face (16) de la plaque de chaudiere et permettent d"assurer une pression sur la gaine de chauffage aux points de contact. Puisqu"il y a de nombreux points de contact, le surchauffage localise (c"est-a-dire les points chauds), est de ce fait elimine.
Designated States:
Publication Language: English (EN)
Filing Language: English (EN)