Dewar flasks made of glass : All Dewar vessels manufactured by KGW-ISOTHERM are made of borosilicate glass 3.3 DIN/ISO 3585 (DWK or Schott Tubing). They are manufactured in accordance with the “Pressure Equipment Directive”, Directive 97/23 EC, (N4 with Annex 1) and DIN EN ISO 16496 “Equipment with vacuum insulation”.
Structure and function of a glass Dewar flask Dewar vessels made of glass are double-walled, vacuum-insulated containers. Their job is to thermally insulate a product stored in them (LN2, CO2 or other coolant) from the ambient temperature. Dewar vessels consist of an inner and an outer flask that are fused together at the top of the neck opening. The space between the inner and outer flask is vacuum-insulated to prevent thermal contact between the product stored in the Dewar vessel and the ambient temperature (contact heat). In addition, Dewar vessels made of glass have a silver mirror coating in the vacuum space to minimize heat radiation. Optimum insulation is achieved by reducing both contact heat (vacuum) and radiant heat (mirroring).
For safety and health reasons, glass Dewar vessels must always be installed in a protective casing. This protective casing can be made of sheet metal, aluminum, stainless steel or a transparent PU coating.
All standard glass Dewar vessels may only be used up to a maximum overpressure of 0.1 bar. Higher working pressures on request.
Dewar Flasks Cylindrical
Max. content: 100 to 8000 ml
Weight: 0,2 to 4,6 kg
Evaporation rate LN2: 0,3 to 0,9 [L/d]
Dewar vessels with flange
Max. Contents: 200 to 8000 ml
Weight approx. : 0.3 to 4.6 kg
Dewar vessels in bowl shape
Max. content: 80 to 5300 ml
Weight: 0,2 to 3,2 kg
With content max. 50 to 6000 ml
Dewar flasks with flat base
Max. Contents: 150 to 2100 ml
Weight approx. : 0,3 to 1,8 kg
Evaporation rate LN2: 0,25 to 0,9 [L/d]
Dewar flasks for magnetic agitator
Mixing range: -200 to +200 °C
Operating temperature : -200 to +80 °C
Magnetic agitator:
-IKA ColorSquid
Dewar transport containers
Max. Contents: 1 to 4 L
Weight approx. : 1,5 to 3,3 kg
Evaporation rate LN2: 1,2 to 1,4 [L/d]
Large Dewar insulating jars in box form
Max. Contents: 10 to 28 L
Evaporation rate CO2: 0.4 to 0.6 [kg/d]
Dewar vessels in spherical shape
Max. Contents: 1 to 10 L
Weight approx. : 1.6 to 6.6 kg
Evaporation rate LN2: 0.2 to 0.6 [L/d]
Stainless steel Dewar flasks
Max. Content approx.: 500 to 3000 ml
Weight approx.: 0,6 to 1,5 kg
Evaporation rate LN2: 1,0 to 3,1 [L/d]