is Cryogenic Treatment?
What can you expect?
* Sophisticated vacuum
insulated cryoprocessors refined and perfected during the 25+
years we've been offering our equipment for sale.
* Reliability and efficiency are built in. Our first machine is
still in service.
* The most efficient machine available.
* Lowest use of liquid nitrogen of any available machine
* Patented heat exchanger technology minimizes thermal stress and
* Totally dry process, no spray bars to spray liquid nitrogen on
* Heating element allows tempering right in the machine.
* Machines in service world wide.
* Industrial grade microprocessor controls, not unreliable home
grade computer control.
* Cylindrical design assures better air flow, more even processing
& eliminates hot corners.
Vacuum insulation offers the ultimate insulation for cryogenic
processing equipment. Because of it, our machines have the lowest
usage of liquid nitrogen in the industry. This cuts the cost of
processing dramatically. Where machines with ordinary insulation
often have to have makeshift fixes such as applying foam to the
outside of the machine after several years, our first vacuum
insulated machine, built in 1985, is still in use. Because one
inch of vacuum insulation provides better insulation than several
feet of conventional insulation, our machines are surprisingly
compact. The machine does not have or require a vacuum pump.
Heat Exchanger Technology
The second thing to look for is a means of cooling the chamber
without thermally shocking the parts in the chamber. Our machines
use heat exchangers to cool the inside of the chamber by gas
kinetics. Nitrogen enters the heat exchanger and a fan circulates
air over it. This gently reduces the temperature within the
chamber and at the same time provides air circulation within the
round chamber so the temperature remains even. In our machines,
Liquid Nitrogen is never brought in contact with the material.
This ensures that the treated material is at no time subjected to
Some machines inject or spray liquid
nitrogen into the chamber and others introduce it into a false
floor. The question of spraying nitrogen into a chamber and hoping
it evaporates before it hits a warm part is based on faith. A
small change in nitrogen pressure or a
clogged or worn nozzle is
all it would take to have nitrogen spray directly on an expensive
engine block or die, thermally shocking the part. We have direct
knowledge of this happening in spray bar equipped machines. The
results were damage to the parts being treated.
Introducing the cold to the bottom of the chamber defies logic.
Cold goes down, so it is more logical to introduce the cold to the
top of the machine. By the way, some of our competitors claim to
be able to control the temperature within the chamber to a
hundredth of a degree. Since they are using thermocouples like
everybody else, this is nonsense, as air within the machine will
vary by more than that over the length of the thermocouple. The
fact is that such precision is unnecessary to achieve perfect
Careful Attention to
Heat Flow into the Chamber
Our careful design reduces the heat flow areas to a minimum. The
cylindrical design reduces the overall sealing area for the top,
which keeps cold loss through the interface between the lid and
the machine to an absolute minimum. This assures minimum nitrogen
consumption. There are no corners where heat flux will be higher
due to greater surface area on the outside. There is a minimum of
conductive heat paths within the chamber, as the inside of the
chamber hangs within the outside. This also eliminates the
tendency of square machines to buckle as they try to accommodate
the difference in thermal contraction between the inside and the
outside of the machine. One of our competitor's machines buckles
so much that the doors crack open and the machine never really
gets down all the way to -300F, nor can it get up to its rated
+300F tempering temperature.
Capabilities Within the Machine
Applied Cryogenics machines are designed with heating elements so
that the load can be tempered within the machine up to +300F.
Having this capability gives the machine user better flexibility
in running parts. Also, due to the extraordinary efficiency of the
vacuum insulation, these heating elements are often necessary to
allow the temperature of the payload to be brought up to room
temperature within a reasonable time.