Cryomech PT415 - Helium Reliquefier General Description

Se
c
1.1
1
c
tion 1
This secti
o
provides
a
used and
e
Helium
R
.1.1 Gen
e
The Cryo
m
helium de
w
establishi
n
helium or
b
A
4 K pul
s
the heliu
m
based on
a
compone
n
heat from
or more
a
refrigeran
t
Flexible s
t
compress
o
The comp
r
pure low-
p
removed
v
series of
o
via the hig
In the col
d
cooling t
o
compress
o
The Puls
e
referred t
o
returning
f
O-ring fitti
with the
C
This red
u
condensi
n
The Liqui
d
bottom o
f
must be
h
Other co
m
monitor, e
relief valv
e
: Over
v
o
n provides
a
a
n overview o
e
xpansion of
R
eliquefi
e
ral descri
p
m
ech Helium
w
ar/cryostats
n
g a closed H
b
e utilized to
s
e tube cryo
r
m
inside the
r
a
closed-loo
p
n
ts: one is th
e
the system;
t
a
dditional ex
p
gas used
i
t
ainless steel
o
r package t
o
r
essor packa
g
p
ressure heli
u
v
ia a heat ex
c
o
il separator
s
h-pressure h
e
d
head, adi
a
o
cryogenic
o
r package vi
e
Tube Cold
o
as the Re-l
i
f
rom the cry
o
ng on the R
e
C
old Head, it
s
u
ces its te
m
n
g chamber;
u
d
helium is
f
f
the conden
s
h
andled wit
h
m
ponents of
l
ectrical feed
t
e
and a vacu
u
v
iew
a
n overview
f this manual
acronyms us
er
p
tion
Re-liquefier i
s
, and then re
t
elium loop. I
t
liquefy heliu
m
r
efrigerator s
r
e-liquefier.
T
p
helium expa
e
compressor
t
he other is t
h
p
ansion cycl
e
i
n the Cryo
m
lines called
o
the cold he
a
g
e works as
f
u
m that is ret
u
c
hanger, and
s
and filters.
T
e
lium flex lin
e
a
batic expan
s
temperature
s
a the low-pr
e
Head is m
o
i
quefier Main
o
stat dewar
e
e
-liquefier M
a
s
heat is ab
s
perature, in
c
u
ntil it contac
t
f
unneled into
s
ing chambe
h
care.
the Helium
t
hrough, silic
o
u
m port.
1-1
discussion o
f
, including th
e
ed in the ma
n
s
designed t
o
t
urn the Liqui
d
t
can be inst
a
m
gas from g
a
upplies the
c
T
he operatio
n
nsion cycle.
A
package, wh
h
e cold head,
e
s to cool it
m
ech cryoge
helium flex l
a
d and carry l
o
f
ollows. An o
i
u
rned from th
the oil from t
h
T
he compres
e
.
s
ion of the
h
s
. The low-
e
ssure helium
o
unted in a
v
Assembly.
T
e
nters into th
e
a
in Assembly
.
s
orbed into t
h
c
reasing its
t
s the 4K con
the Liquid
h
r to the cry
o
Re-liquefier
o
n diode, an
d
f
Cryomech
H
e
organizatio
n
ual.
o
recondense
d
Helium to t
h
a
lled into cry
o
a
s cylinder to
c
ryorefrigerat
i
n
of a cryog
e
A
complete s
y
ich compres
s
which takes
down to cr
y
nic systems
ines carry c
o
o
w-pressure
i
l-lubricated
c
e cold head.
h
e compress
sed helium i
s
h
elium and f
u
-
pressure h
e
flex line.
v
acuum insul
T
he room te
m
e
condensin
g
.
As the wa
r
h
e heat exch
density, dr
o
densing surf
a
h
elium Retur
n
o
stat. The r
e
are a press
u
d
heater ass
e
H
elium Reliq
n, basic defi
n
the boil off fr
o
h
e dewar/cry
o
o
stats alread
y
fill a dewar.
i
on necessa
r
e
nic refriger
a
y
stem consis
s
es refrigera
n
the refrigera
y
ogenic tem
p
is 99.999%
o
mpressed h
e
helium back.
c
ompressor c
o
The heat of
c
ion process i
s
s
then fed to
u
rther heat
r
e
lium then
r
ated conden
m
perature he
l
g
chamber th
r
m helium co
m
angers on t
h
o
pping it lo
w
a
ce, where it
n Line whic
h
e
turn line i
s
u
re controlle
e
mbly as well
Overvie
w
uefiers. It al
s
n
itions of ter
m
o
m liquid
o
stat
y
full of liquid
r
y to conden
s
a
tion system
ts of two maj
o
n
t and remov
e
nt through o
n
p
eratures. T
h
%
pure heliu
m
e
lium from t
h
o
mpresses t
h
c
ompression
s
removed in
the cold he
a
r
emoval allo
w
r
eturns to t
h
sing chamb
e
lium gas/vap
o
rough the 1/
4
m
es in conta
h
e Pulse Tub
e
w
er inside t
h
condenses.
h
connects t
h
s
delicate a
n
r, temperatu
r
as a pressu
r
w
s
o
m
s
s
e
is
o
r
e
s
n
e
h
e
m
.
h
e
h
e
is
a
a
d
w
s
h
e
e
r,
o
r
4
"
ct
e
.
h
e
h
e
n
d
r
e
r
e