2 TTK 600 - An Overview
D52IB001EN-G
17
Fig. 17: "Venturi-Nozzle - Safety Box"
1 "Venturi-Nozzle - Safety Box"
2 N2 inlet hose
3 N2/Air exhaust hose
4 Compressed-air connector
5 Overpressure-relieve valve
On top of the safety box is a Venturi nozzle which
creates a vacuum if the compressed air is switched
on. This vacuum ensures that liquid nitrogen is
sucked from the Dewar vessel through TTK 600 and
provides in this regard the cooling power that is
needed for low-temperature experiments. The
evaporated nitrogen is removed through the ex-
haust hose of the Low-Temperature Equipment and
directed into the Venturi-Nozzle - Safety Box. This
box is made as additional safety device for the cool-
ing system.
Liquid nitrogen that may escape from the gas ex-
haust hose of the Low-Temperature Equipment
would accumulate in the Venturi-Nozzle - Safety
Box until a certain filling level is reached and a float-
er inside the box closes the gas outlet of the box to
a minimum level. Due to that the flow through the
system is decreased which results in a warming of
the whole cooling system. For the error case that the
outlet hose of the box is blocked, an additional over-
pressure relief valve that opens at a pressure of
3 bar is integrated in the lid of the box. In this way a
safe use of liquid nitrogen is ensured that prevents
liquid nitrogen to escape from the system in case of
an error or mishandling.
The compressed air that is needed for the activation
of the Venturi nozzle is provided by CCU 100. Active
cooling is only needed to cool the sample holder to
temperatures around room temperature and be-
low.The so-called Cooling Limit (CL) defines the
threshold temperature for active cooling. The value
can be changed between 20 and 55 °C (see
chapter 6.3.1 for further information). If the tempera-
ture set point is <CL, CCU 100 opens the com-
pressed-air connection to the Venturi nozzle and
enables in this way the cooling of the system. If the
sample is heated above the threshold temperature,
CCU 100 closes the compressed-air connection
and thus stops the supply of LN2 to the cryostat of
TTK 600.
For further details see chapter 6.5.1 Controlling the
Liquid Nitrogen Cooling.
2.4.2 Compressed-Air Cooling Equipment
The compressed-air cooling equipment consists of
the following components:
• Air-Cooling Set TTK 600 (cat.no.165420)
In order to meet the requirements for the com-
pressed air regarding pressure and purity, Anton
Paar GmbH recommends to use the following pres-
sure regulator with filters:
• Air-Service Unit (cat.no. 6931)
For frequent or long-time cooling of the sample hold-
er to < 10 °C Anton Paar GmbH recommends to use
the following component in order to prevent prob-
lems with condensed water or ice inside the cooling
unit:
• Compressed-air Dryer (cat.no. 81393)
When compressed-air is supplied to the cooling unit,
it generates a flow of cold gas which is directed into
the cryostat inside the sample chamber and cools
the sample holder. The supply of compressed-air to
the cooling unit is controlled by CCU 100.
1
2
3
4
5
DANGER
Risk of injury.
Never open the lid of the Venturi-Nozzle - Safety
Box during operation.
Summary of Contents for TTK 600
Page 2: ......
Page 74: ...Appendix B Sample Chamber Dimensions 74 D52IB001EN G Appendix B Sample Chamber Dimensions ...
Page 75: ...Appendix C Declaration of Conformity D52IB001EN G 75 Appendix C Declaration of Conformity ...
Page 77: ...Appendix D Spare Parts and Accessories D52IB001EN G 77 176383 COOLING MODE SWITCHING VALVE ...
