Cryogenic liquid reclamation system is used as an add-on unit to the nitrogen system of environmental test laboratories to salvage liquid nitrogen presently being treated as waste. The system may be installed indoors or outdoors provided the gas boiled off from the cryogenic liquid is vented to the outside

Daderian, S. M.

English

NASA Technical Reports Server

November 1967	 (Q;;^) 
NASA TECH BRIEF	
1 
NASA Tech Briefs are issued to summarize specific innovations derived from the U.S. space program, 
to encourage their commercial application. Copies are available to the public at 15 cents each 
from the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
Concept for Cryogenic Liquid Reclamation System 
Vent Line	 Pipeline	 To Research And Development I	 \ -_--- Equipment 
Check 
Sensing Element 
Lead Lines 
Level 
Controlle7trjl... 
High Limit 
Sensing - 
Element 
Motor
Low Limit 
Sensing 
Element 
Phase Separator 
Recervoir 
Discharge. 
Line 
The problem: 
A system is needed for salvaging liquid nitrogen 
that is presently being treated as waste because there 
is no known system that operates on an intermittent 
or demand basis for salvaging cryogenic liquids. 
Available closed loop systems do not provide the 
stop-start capabilities required. The liquid nitrogen 
not consumed during experiments in space environ-
ment laboratories is usually dumped on the ground
Inlet Line 
_Removable Cap 
Gas Discharge Line 
Vent Pot 
Pump 
Discharge 
Line 
	
Vent	 Cryogenic 
	
- Line	 Liquid Supply Line 
Trap /
Pump Motor 
causing visibility problems in the immediate vicinity. 
A successful reclamation system would eliminate the 
visibility problem and result in obvious cost savings. 
The solution: 
A concept for a cryogenic liquid reclamation system 
that may be used as an add-on unit to the nitrogen 
system of environmental test laboratories to salvage 
liquid nitrogen presently being treated as waste. 
-	
(continued overleaf) 
.  
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19670000420 2020-03-11T21:09:43+00:00Z
How it's done: 
The cryogenic cooling agent is forced through the 
pipeline-by the pressure maintained within the re-
search and development equipment,. which would 
have to be at least higher than atmospheric as the 
reservoiris vented to atmosphere. The reservoir also 
serves as a phase separator since the fluid discharge 
from the R & D equipment is in both a liquid and 
gaseous state. The reservoir is a specially made dewar 
flask constructed of two high quality cylindricalshells 
separated by an ultrahigh thermal insulating vacuum. 
The cap, which is removably attached to the reservoir, 
has openings for the inlet line, the vent line, and 
sensing element lead lines. The vent line, which vents 
gas to the atmosphere, has a check valve to prevent 
reverse flow. 
Within the reservoir there are two sensing elements: 
(1) the high limit sensing element and (2) the low 
limit sensing element. The sensing elements are con-
nected to a level controller by the lead lines. An 
opening in the bottom of the reservoir provides a 
point of connection for a discharge line, which is con-
nected to a pump. The difference in elevation between 
the reservoir and the pump must be sufficient to pro-
vide a net positive suction head of pump which will be 
determined by the type of cryogenic liquid being sal-
vaged and pump design. 
- The motor is electrically connected to the level con-
troller so that the pump may be started and stopped 
by the level controller as a function of the amount of 
liquid in the reservoir. A vent line which is connected 
to the trap vents the gas that may have boiled off 
from the cryogenic liquid contained in the discharge 
line. Electrical resistance heater tape is wrapped 
around the bearings of the pump to avoid bearing 
freeze-up. The resistance tape is on only during the 
times the pump is not running, since during the times
of operation sufficient heat is generated in the pump 
motor to prevent bearing freeze-up. 
The pump discharge line is connected to the cryo-
genic liquid supply line so that salvaged cryogenic 
liquid may be fed back through the R & D equipment 
or in the event there is insufficient demand for the 
cryogenic liquid being pumped, the liquid may be 
forced back into the cryogenic liquid supply tank. 
The cryogenic liquid reclamation system is insulated 
to minimize heat gain from external sources. 
Notes: 
1. It may be possible to use this reclamation system 
on most cryogenic liquids that will not cause 
explosions and where the purity of the liquid is not 
of critical importance. 
2. The system may be installed indoors or outdoors 
provided the gas boiled off from the cryogenic 
liquid is vented to the outside. 
3. This development is in the conceptual stage only, 
and as of date of publication of this Tech Brief, 
neither a model nor prototype has been con-
structed. 
4. Inquiries concerning this invention may be di-
rected to:
Technology Utilization Officer 
NASA Pasadena Office 
4800 Oak Grove Drive 
Pasadena, California 91103 
Reference: B67-10420 
Patent status: 
Inquiries about obtaining rights for commercial 
use of this invention may be made to NASA, Code 
GP, Washington, D.C. 20546. 
Source: Setrak M. Daderian
Jet Propulsion Laboratory

(N P0-10322) 
Brief 67-10420	 -	 Category 02


Concept for cryogenic liquid reclamation system

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