Modified sorption trap for use in high vacuum systems contains provisions for online regeneration of sorbent material. Trap is so constructed that it has a number of encapsulated resistance heaters and a valving and pumping device for removing gases from heated sorbing material. Excessive downtime is eliminated with this trap

Barrington, A. E.

Caruso, A. J.

English

NASA Technical Reports Server

November 1970	 Brief 70-10449 
NASA TECH BRIEF
	
/ 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage commercial 
application. Tech Briefs are available on a subscription basis from the National Technical Information Service, Springfield, 
Virginia 22151. Requests for individual copies or questions relating to the Tech Brief progam may be directed to the Tech-
nology Utilization Division, NASA, Code UT, Washington, D.C. 20546. 
Sorption Vacuum Trap 
The problem: 
To develop a sorption trap for use with high-vacuum 
systems. Molecular-sieve traps fabricated of 304-stain-
less steel with the sieve contained in stainless steel 
trays or wire cages are presently used in commercial 
practice. An external heating mantle provides a means 
of heating the trap for bakeout and for the regenera-
tion of the molecular-sieve material at a temperature of 
350° to 450°C. 
The solution: 
A modified sorption trap that can be used in high-
vacuum systems, and which contains provisions for 
online regeneration of the sorbent material. The trap 
is so constructed that it has a number of encapsulated 
resistance heaters and a valving and pumping device 
for removing the gases from the heated sorbing mate-
rial. This sorption trap provides a method for eliminat-
ing excessive downtime. 
How it's done: 
The external heating mantle used in normal practice 
has the following disadvantages: (1) it is difficult to 
obtain heating mantles for sorption traps larger than 
10 in. in diameter; (2) it is inefficient; and (3) because 
heat is conducted to the flanges of the trap, metal 
gaskets must be used. Although less expensive elas-
tomeric gaskets, which are also easier to replace, could 
be used in lieu of metal ones, they cannot be subjected 
to temperatures in excess of 100°C for prolonged pe-
riods. 
An internal heating coil is feasible for use in a 
vacuum system, but its usefulness is marginal because 
of problems in electrical insulation; replacement of 
such a coil necessitates a major shutdown of the sys-
tem.
These problems can be overcome, however, by 
mounting the wire cage containing the molecular sieve 
on the supports of a flange that has a conventional 
chevron baffle; an optical baffle is also included. Both 
the flange and chevron baffle can be cooled with water. 
A number of vacuum-tight stainless steel tubes, typi-
cally 5/8 in. in diameter, are placed on the lower trap 
flange. A thermometer can be mounted on one of these 
tubes for thermostatic control. Immersion heaters, 
normally 1/2 in. in diameter, 12 in. long, and having 
a 700 W capacity, are inserted from outside the 
vacuum system. A sorption trap with a diameter of 
10 in. requires 5 such heating units. This heating unit 
is the most efficient available, and it can be replaced 
easily in a high-vacuum system. 
Note: 
No further documentation is available. Specific 
questions, however, may be directed to: 
Technology Utilization Officer 
Headquarters 
National Aeronautics 
and Space Administration 
Washington, D.C. 20546 
Reference: B70-10449 
Patent status: 
This invention has been patented by NASA (U.S. 
Patent No. 3,469,375) and royalty-free license rights 
will be granted for its commercial development. In-
quiries about obtaining a license should be addressed 
to NASA, Code GP, Washington, D.C. 20546. 
Source: Anthony J. Caruso and Alfred E. Barrington 
Electronics Research Center 
(ERC-9005 1) 
Category 06 
This document was prepared under the sponsorship of the National
	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States
	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States
	 will be free from privately owned rights.
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Sorption vacuum trap

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