Browse Prior Art Database

Vertical Cryo Clean Vessel Trap

IP.com Disclosure Number: IPCOM000047344D
Original Publication Date: 1983-Nov-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 3 page(s) / 93K

Publishing Venue

IBM

Related People

Carbone, QJ: AUTHOR [+2]

Abstract

This invention concerns a cryogenic trap for condensing atmosphere from a vacuum system process chamber and for condensing backstreaming vacuum pump hydrocarbons which would otherwise contaminate the process chamber. The trap is designed to be serially located between the vacuum system process chamber and the vacuum system diffusion pump. The trap features an optically dense "honeycomb" baffle centrally positioned within the trap to interrupt atmosphere flowing toward the diffusion pump and to also interrupt warm air currents which would backstream diffusion oil to the vacuum chamber. The trap additionally features a helical cooling coil coaxially located with respect to the baffle and radially displaced from it.

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Vertical Cryo Clean Vessel Trap

This invention concerns a cryogenic trap for condensing atmosphere from a vacuum system process chamber and for condensing backstreaming vacuum pump hydrocarbons which would otherwise contaminate the process chamber. The trap is designed to be serially located between the vacuum system process chamber and the vacuum system diffusion pump. The trap features an optically dense "honeycomb" baffle centrally positioned within the trap to interrupt atmosphere flowing toward the diffusion pump and to also interrupt warm air currents which would backstream diffusion oil to the vacuum chamber. The trap additionally features a helical cooling coil coaxially located with respect to the baffle and radially displaced from it. The cooling coil is arranged to carry a cryogenic fluid, for example, liquid nitrogen, to the interior of the trap to enhance trapping action. The trap additionally features mountings for the baffle and coil which thermally insulate the baffle and coil from heat generated by the system pump. More particularly, the trap in accordance with this article is shown in Fig. 1. As shown, trap 10 comprises a housing 12 having an inlet 14 which may be coupled to the process chamber of a vacuum system (not shown). Additionally, trap 10 is seen to include an outlet 16 which may be coupled to the vacuum system pump, for example, a diffusion pump (not shown). Continuing with reference to the figure, housing 12 of trap 10 is seen to include a trapping chamber 18 which is in communication with housing inlet 14 and outlet 16. As shown, a baffle 20 is coaxially located within trapping chamber 18. Baffle 20 is of cone shape and provided with multiple perforations 22 to permit gas flow through the baffle.

Baffle 20 is arranged within trap...