Thermoacoustic Stirling Cryocooler

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Thermoacoustic Stirling Cryocooler

Model # For Liquefaction & Boil-Off Gas Systems

RIX manufactures highly reliable, thermoacoustic Stirling (pulse tube) cryocoolers for a variety of OEM, Military, and R&D applications. Each unit is driven by two robust linear reciprocating motors with clearance seal pistons, providing wear free operation with no required lubrication. The dual opposed motor/piston design within the pressure wave generator (PWG) is naturally balanced, reducing vibration and noise. RIX cryocoolers operate at temperatures ranging from 40–200K with rated capacities of a few Watts to 800 Watts at 77K.
Description

Details

RIX's cryocooler design is completely absent of cold moving parts or seals, eliminating maintenance that is required of most other cryocooler technologies. When mass loading at the cooled point is of concern, RIX offers remote coldhead systems (Flexibly Attached Remote, or FAR), separating the pressure wave generator from the cryogenic coldhead, which further reduces vibration. To improve power consumption and increase versatility, each cryocooler is designed to be adjusted “on-the-fly” to match varying cooling load requirements. These advantages are accompanied by competitive pricing in both small and large quantities, making RIX cryocoolers ideal not only for laboratory use but also for HTS, medical, liquefaction, military and aerospace applications.

HOW IT WORKS:

The Thermoacoustic Operating Principle

The base cryocooler unit consists of a pressure wave generator driven by two  linear reciprocating motors and a thermoacoustic Stirling (pulse-tube) coldhead.  The acoustic Stirling coldhead consists of a warm heat exchanger, a regenerator, a cold heat exchanger, a thermal buffer tube, a hot heat exchanger, an inertance tube, and an inertance tank.  The figure below shows an inline cryocooler configuration for clarity, but the actual coldhead is “folded over” at the cold heat exchanger to create a cryocooler with an accessible, exposed cold zone.

1) Pressurized helium gas is cyclically compressed and expanded relative to the mean pressure (charge pressure) by the pistons of the PWG.

2) With each forward stroke of the pistons, the gas moves through the aftercooler, or warm heat exchanger, where heat is removed. The gas parcel continues through the regenerator, which precools it before reaching the cold heat exchanger.

3) As the gas moves toward the cold heat exchanger, gas in the thermoacoustic network (thermal buffer tube (sometimes called a pulse tube), hot heat exchanger, reservoir) also moves in the same direction.  Even as the driven gas stops advancing, when the pistons reach their upper limits, the network’s gas continues moving, driven by its own inertia in the high-speed inertance tube.  This acts like a virtual piston, moving away from the cold exchanger, which expands the gas in that area.  As it expands, it gathers heat from surroundings (the area or substance to be cooled).

4) The pistons begin withdrawing and helium then moves back through the regenerator and aftercooler.  Still delayed by its inertia, the gas in the network follows and the cycle begins again.

The heat exchangers are cooled by local water, or an optional closed water loop that consists of a reservoir, a pump, and a liquid-to-air heat exchanger.  If an air-cooled cryocooler is desired, the motors and warm heat exchangers are cooled by a fan which blows over the motor enclosures and a heat sink connected to the aftercooler. This option is only available on RIX’s smaller cryocoolers, the 2s102K and 2s132K.  It is recommended that these small PWG’s be convectively cooled during operation to assure optimal performance from the cryocooler.

Features

Features

The heart of RIX's long-life, no-maintenance technology is the resonant linear reciprocating motors and alternators. These have a unique wear-free suspension system, with unlimited life and pure single-axis motion. This eliminates contact between moving parts and associated lubrication requirements. RIX motors utilize an innovative interdigitating moving magnet design with robust coil-over-iron stators. They are recognized throughout the world as the premier linear reciprocating motor/alternator. Combine these with RIX’s unique thermoacoustic Stirling coldheads and you have a cryocooler that requires no maintenance and has very low vibration.

SYSTEM SPECIFICATIONS:

 

Cryocooler Model

2s102K

2s132K

2s226K

2s241K

2s362K

Approximate Capacities @ 77K (W)

7

28

140

190

800

Approximate Capacities @ 150K (W)

27

80

390

600

2,900

No load temperature (K)

50

45

37

50

40

Power consumption @ rated condition (W)

275

600

2,750

4,500

22,000

Electrical requirements*

110Vac max., 1Φ, 60Hz

110Vac max., 1Φ, 60Hz

208Vac max., 1Φ, 60Hz

208Vac max., 1Φ, 60Hz

380Vac max., 1Φ, 60Hz

Maximum operating current (amps)

4.25

9

30

40

80

Ambient operating temperature

320-900F     (00-320C)

320-900F         (00-320C)

320-900F           (00-320C)

320-900F           (00-320C)

320-900F           (00-320C)

Maintenance Interval

None

None

None

None

None

Rejection method

H2O or Air

H2O or Air

H2O

H2O

H2O

Cooling flow rate (H2O)

1 liters/min

2 liters/min

10 liters/min

12 liters/min

50 liters/min

*Normal for stand unit. Custom voltage and frequency available

Cool down time to 77K for all models ~ 25 minutes

All specifications subject to change

Specifications

Additional Information

Features

The heart of RIX's long-life, no-maintenance technology is the resonant linear reciprocating motors and alternators. These have a unique wear-free suspension system, with unlimited life and pure single-axis motion. This eliminates contact between moving parts and associated lubrication requirements. RIX motors utilize an innovative interdigitating moving magnet design with robust coil-over-iron stators. They are recognized throughout the world as the premier linear reciprocating motor/alternator. Combine these with RIX’s unique thermoacoustic Stirling coldheads and you have a cryocooler that requires no maintenance and has very low vibration.

SYSTEM SPECIFICATIONS:

 

Cryocooler Model

2s102K

2s132K

2s226K

2s241K

2s362K

Approximate Capacities @ 77K (W)

7

28

140

190

800

Approximate Capacities @ 150K (W)

27

80

390

600

2,900

No load temperature (K)

50

45

37

50

40

Power consumption @ rated condition (W)

275

600

2,750

4,500

22,000

Electrical requirements*

110Vac max., 1Φ, 60Hz

110Vac max., 1Φ, 60Hz

208Vac max., 1Φ, 60Hz

208Vac max., 1Φ, 60Hz

380Vac max., 1Φ, 60Hz

Maximum operating current (amps)

4.25

9

30

40

80

Ambient operating temperature

320-900F     (00-320C)

320-900F         (00-320C)

320-900F           (00-320C)

320-900F           (00-320C)

320-900F           (00-320C)

Maintenance Interval

None

None

None

None

None

Rejection method

H2O or Air

H2O or Air

H2O

H2O

H2O

Cooling flow rate (H2O)

1 liters/min

2 liters/min

10 liters/min

12 liters/min

50 liters/min

*Normal for stand unit. Custom voltage and frequency available

Cool down time to 77K for all models ~ 25 minutes

All specifications subject to change

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