or, Automatic LN2 fill system for microscope cold stages on fixed temperature of -192 C..
Are you still poring LN2 into your DSC by hand, several times per measurement?
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 Adaptor for Shimadzu DSC60 and similar
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| picture shows pump mounted on a 35 Liter dewar possible dewars are 25, 35 or 50 Liter pump can be used on other type dewars as long as the dewar has a NW50 flange (new window) |
total system height 79 cm |
Norhof manufactures cooling systems in which Liquid Nitrogen (LN2) is used as the cooling medium. LN2 is supplied without any pressure and filling an application is like a teapot filling a teacup.
You may compare our liquid nitrogen dispenser system with a water tap , but instead of giving water, it gives LN2, starting with some drops, up to 1 Liter/minute.
Liquid Nitrogen (LN2)
The reservoir dewar can safely stand next to your working place. No dangerous LN2 pressures exits.
When your DSC needs cold, the system is switched on by the Shimadzu DSC, starting to supply LN2. (* for other DSC's pump may be switched by 5 Volt signals or RS232 commands, or by the button on the pump)
When switched ON, the system starts building a small over pressure, forcing the liquid gently to rise into the fill line, and fall into your dry DSC reservoir. The sensor, placed also in the reservoir, makes the filling slower when there is ab.4 cm level. If the level becomes lower, filling is increased. If the level becomes too high, filling is slower, thus keeping the level continuous on 4 cm.
Usage
The majority of this system find use in the field of scientific instruments, physical laboratories, research centers etc. where DSC measurements are made with a DSC which needs LN2 during the measurement process.Use of this system is for example for:
* For other applications where automatic LN2 administration is needed, we have the #900 serie of microdosing pumps, see the left column
| WORKING PRINCIPLE The pressure above the liquid level inside the dewar is built by heating a small amount of liquid in the bottom of the dewar. With only up to 50 mBar of overpressure, the liquid will gentle rise out of the rise pipe and fall into the fill hose. Because we evaporate some LN2 to build pressure, there is no adding of ice inside the dewar, such as with manual systems which use air from the environment. |
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In the Norhof LN2 cooling systems Liquid Nitrogen is stored in pressure less Dewars. When LN2 is required, a small overpressure is generated by a small heater element in the LN2, and liquid flows out of the system like water from a tap, without spilling, noise, vibrations etc.
The advantages are numerous:
• the system is extremely safe
the operator comes not in contact with LN2.
• the system is time saving
the operator does not need to poor in LN2 several times.
• the system can autofill the DSC just with a press on the start button
this means that the system is ready for use 24 hours a day.
• the system delivers LN2 without any pressure
this means without noise, vibration, excessive waste, etc.
• there is no external LN2 valve required
that implies no unnecessary heat input which spoils a lot of LN2
• there is no internal LN2 valve in the pump
LN2 comes out of insulated tubing without making contact to warm metallic parts, so very fast
• there is a very low thermal masse to cool down in the pump
LN2 comes out within 60 seconds.Filling efficiency is better than 90%, due to very less loss for cooling down pump parts.
• there is a very low thermal connection to the ambient temperature
This means that the system is extremely economic in stand-by. Typical usage less than 0,5 Liter / day
• P.E.D. 99/36/EC (Pressure European Directive) for pressurized vessels does not apply for this system
The maximum possible pressure is lower than 300mBar.Therefore this system is allowed to be used inside the lab, near your working place, without danger.
Technical Specifications
Static evaporation rate < 0,5 liters per day Filling flow rate Dripping up to 0.1 Liter/minute, depending on application level Maximum working pressure < 300 mBar Power connection 115V / 230V AC with supplied power supply or 12 Volt AC/DC Power consumption average 10 Watts, during pumping 50 watts Storage container volume 25 Liter(on request) 35 Liter (standard) 50 Liter Outside dimensions (round) 395 480 500 mm Height dimensions 736 643 727 mm Weight (empty, full) 10 / 31 13 / 41,5 17 / 51,5 kg System includes Monitor software, to monitor pump behavior, to preset filling height and flow rate. External steering 5 volt signals for ON, OFF RS232 signals for ON, OFF
Alarms/warning acoustical/ visual / mechanical
Dewar empty, 5 liters left, broken sensor, overpressure protection Options Adaptor for Shimadzu DSC60 or similar Transport trolley 5 wheels (12 cm height)
Stand for pump (when dewar is refilled)
for more models use links in left column
