QUICK INTRODUCTION

NORHOF LN2 MICRODOSING SYSTEM   series #900

       ( covering model #905, #910 and #915 )

• Precision controlled administration of smaller amounts of LN2, from dripping up to 1 liter/minute
• Variable flow, controlled by setting, sensors(s) , remote signals or computer.
• Pressure-less flowing LN2, without spilling, noise, vibrations etc. 

	video pumpflow on 30 mBar
picture shows pump on 35 liter dewar total system height 79 cm (excl. wheels)	if video not visible, click HERE    (video may be blocked by your browser settings)

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, with an adjustable flow, possible to regulate from some drops, up to 1 Liter/minute.

Liquid Nitrogen (LN2)

The flow is variable and can be optimized to the application.

Flow control is on the system itself or by remote signals. With one and the same system the flow range is from

• dripping for e.g. maintaining a certain subzero temperature
• to full flow for filling e.g. a small Dewar

The majority of our systems find use in the field of scientific instruments, physical laboratories, research centers etc. where precise control over subzero temperatures is required or where a LN2 flow of app. 1 L/min is sufficient. Industrial systems with 15 L/min based on the same principle are also available.

Use of this system is for example for:

• auto-filling small dewars
• autofill LN2 for CCD dewars
• autofill small dewars for FTIR spectrometer
• autofill cryostats
• autofill Dry Shippers
• DSC (Differential scanning calorimetry )
• Infrared spectrometry, HgCdTe infrared detectors
• cooling laser units
• cooling electron microscopes
• cooling MCT detectors
• filling coldtraps automatically
• washing Xtals
• XPS- m X-ray Photoelectron Spectroscopy
• cooling low-noise amplifiers and noise-sources
• cooling High efficiency lamps
• cooling a small sample on an ultra-low temperature between -180 and ambient
• cooling SEM EDX

WORKING PRINCIPLE The pressure above the liquid level inside the dewar is carefully controlled and therefor the flow. With only 100 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.

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 micro processor controlled 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:

• 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

• there is no additional control unit required

which adds to a clean and elegant setup

• the pump is software driven and many control modes are already built-in

like 1-point level control, 2-point level control, timer based control, subzero temperature control, flow control by 0-5V input, control by RS232 line, etc.

• level or temperature sensors are plugged directly into the pump housing

and not into a separate control box

• the system can deliver LN2 liquid with a flow optimized for the application

without noise, vibration, excessive waste, etc.

• the variable flow feature makes subzero temperature control extremely easy

see under SOFTWARE > sample drivers > freeze curve

• the system is foreseen to be connected to a PC

great for history writing or remote control

• P.E.D. 92/23/EC (Pressure European Directive) for pressurized vessels does not apply for this system

The maximum possible pressure is 300mBar.Therefore this system is allowed to be used inside the lab, near your working place, without danger.

 

for more info use links in left column