A helium liquefier has been developed with a Gifford-McMahon cryocooler using the cold enthalpy available at the first stage, the inter-stage, and the second stage of the cryocooler. Most of the enthalpy of the helium gas at 300 K is absorbed in the first stage by a coaxial heat exchanger and inter-stage region of the cryocooler. Pre-cooled helium gas is liquefied at the second stage heat exchanger where the final cooldown and condensation happens. The measured production capacity of the liquefier is 17.4 l/day at atmospheric pressure. The whole setup has been designed to work in a coaxial configuration where the two heat exchangers, the cryostat, and the dewar are symmetrically placed around the central axis.

1.
G.
Thummes
,
C.
Wang
, and
C.
Heiden
, “
Small scale 4He liquefaction using a two-stage 4 K pulse tube cooler
,”
Cryogenics
38
(
3
),
337
(
1998
).
2.
C.
Wang
, “
Helium liquefaction with a 4 K pulse tube cryocooler
,”
Cryogenics
41
,
491
(
2001
).
3.
C.
Wang
and
R. G.
Scurlock
, “
Improvement in performance of cryocoolers as condensers
,”
Cryogenics
48
,
169
(
2008
).
4.
N.
Masashi
,
I.
Takashi
,
Y.
Hideto
 et al, “
Helium liquefaction by a Gifford-McMahon cycle cryocooler
,”
Adv. Cryog. Eng.
35B
,
1251
1260
(
1990
).
5.
P.
Schmidt-Wellenburg
and
O.
Zimmer
, “
Helium liquefaction with a commercial 4 K Gifford-McMahon cryocooler
,”
Cryogenics
46
(
11
),
799
803
(
2006
).
6.
X.
Dong
,
L. H.
Gong
, and
L. F.
Li
, “
A self-circulation helium liquefaction system with five 4 K G-M cryocoolers
,”
Cryogenics
51
,
331
336
(
2011
).
7.
D.
Xu
,
L. H.
Gong
, and
L. F.
Li
, “
Experimental investigation and optimization of small-scale helium liquefaction with multi-cryocoolers
,”
Cryogenics
69
,
10
17
(
2015
).
8.
A.
Ravex
,
T.
Trollier
,
J.
Tanchon
, and
T.
Prouvé
, “
Increase in performance of 4 K pulse tube cryocooler
,” in
Proceedings of the Cryo Prague 2006/ICEC
(
International Institute of Refrigeration (IIR)
,
2006
), Vol. 21, pp.
515
524
.
9.
C.
Wang
, “
Intermediate cooling from pulse tube and regenerator in a 4 K pulse tube cryocooler
,”
Cryogenics
48
,
154
159
(
2008
).
10.
Y.
Hiroshi Asami
and
H.
Mitsuru Suzuki
, “
Refrigerator having regenerator
,” U.S. patent 5,481,879 (09 September 1996).
11.
VDI Heat Atlas
, 2nd ed. (Springer, 2010), pp.
673
677
.
You do not currently have access to this content.