Multiple transfer lines

The transfer of cryogenic liquid helium places high demands on insulation and thermodynamic design. Multiple transfer lines from Cryotherm, so-called Multilines, almost completely prevent the heat input due to their sophisticated design.

Substance
Temperature
Scope of application
Multiple transfer lines - Multiple transfer lines (Multilines) for extremely low heat inflow rates. - img0
Multiple transfer lines - Multiple transfer lines (Multilines) for extremely low heat inflow rates. - img1
Multiple transfer lines - Multiple transfer lines (Multilines) for extremely low heat inflow rates. - img2
Low evaporation rate
Rugged construction
Optimized Super Insulation

Low temperature cooling with liquid helium

The low temperature level of -269°C (4K) combined with the low evaporation enthalpy of liquid helium makes high demands on the care taken in the manufacture of these transfer lines. Even a heat input of only 0.7 W leads to the evaporation of one litre of liquid helium per hour. For this reason, it is necessary to keep the thermal radiation acting on the liquid helium as low as possible. Multiple transfer lines from Cryotherm, so-called Multilines, almost completely prevent the heat input due to their ingenious design.

To reduce the heat input by radiation, helium flow, helium return and liquid nitrogen flow are first wrapped with several layers of highly reflective foil (super insulation). The connection of the nitrogen return to a thermal shield surrounding these four lines further reduces the radiation input. The thermal shield also receives several layers of super insulation. Finally, this structure is surrounded by a vacuum jacket and evacuated.

The vacuum space created effectively protects against heat input by convention and the thermal shield, actively cooled with liquid nitrogen, effectively prevents heat input from the outer pipe to the internal helium lines. The fixation of the inner pipes makes high demands on flexibility at different temperatures and low heat input. The design must be carried out with the utmost care. The described Multiline with four inner lines carrying process gas is only one possible design of the Cryotherm Multilines.

Experienced Cryotherm project engineers design the insulation and diameters of the required process lines for each application. Depending on customer requirements, additional lines can be integrated. (e.g. 2k pump lines)

Convincing advantages:

  • lowest heat inflow rates
  • up to 44,880 sequins of 0.25 millilitres each
  • up to 400 bags of 25 millilitres each
  • Robust, welded construction of highly corrosion-resistant, cold-resistant stainless steel for a long service life
  • inner and outer container each separately Helium leak tested
  • Integrated vacuum closure safety device
  • Most-selected separation system
  • effective protection against heat input by integration of thermally cooled shields

Certificates

Certificate
Certificate

Multiple transfer lines

The transfer of cryogenic liquid helium places high demands on insulation and thermodynamic design. Multiple transfer lines from Cryotherm, so-called Multilines, almost completely prevent the heat input due to their sophisticated design.