Brooks Polycold P-102 - 1 Introduction; System Summary; Basic Principles of Operating for the Polycold Refrigeration Cycle

1. Introduction
System Summary User Manual
1. Introduction
System Summary
The Polcold® P-102 Portable Cryocooler provides compact, portable, and easy-to use alternatives to
liquid nitrogen used in small vacuum systems. These cryogenerators use refrigerants in a closed loop
system. The refrigerants are:
l Safe
l Non-flammable
l Non-toxic
l HCFC-free
This means there is no moving of heavy liquid nitrogen dewars. Also, there is no running out of
cryogen causing downtime.
Installation is quick and easy. Either a cold probe is inserted into a housing or a chevron baffle is
installed between a diffusion pump and a high vacuum valve. The cold probes and chevron baffles are
referred to as cryosurfaces. These are part of the refrigerant line. Removing them causes a loss of
refrigerant.
Cold trapping applications include:
l Helium mass spectrometer leak detectors
l Chevron baffles for diffusion pumps up to 6 inches (160 mm) in diameter
l Vapor trapping cold probes that protect mechanical pumps on small vacuum systems.
Basic Principles of Operating for the Polycold Refrigeration Cycle
This cooling process is an auto cascade refrigeration system. A patented mixture of non-flammable
and safe CFC-free and HCFC-free refrigerants is compressed and circulated by a compressor. In a
simplified version, the Polycold refrigeration cycle comprises:
1. Compressing a mixture of refrigerants
2. Partially condensing the higher boiling fractions in an air-cooled condenser
1-1 Brooks Automation