KGW Isotherm Aluminium Brushed Spherical Dewar Flasks
Area of application
- Laboratory technique
- medicinal technique
- Biotechnology
- storing and company internal short-distance transport
- for liquid nitrogen (LN2)
Features of performance
- reliably and economically
- Dewar flasks according to DIN EN ISO 16496
- glass material according to ISO 3585
- nominal capacity from 1 to 10 litres
- protective casing out of aluminium, brushed
Description of complete flasks
Types and accessories
- AL =protective casing out of aluminium, brushed
- carrying handle = pure aluminium
- lid = aluminium casing with PU inlet
- Shock rubber = cellular rubber
Temperature ranges
- glass refill from -200°C to + 150°C
- lid from -200°C to + 80°C
- casing with mounting rubber and Latizell buffer from -10°C to + 60°C
Technical Data
| Typ | max. Inhalt ca. [ L ] |
A mm |
B mm |
C mm |
D mm |
H mm |
B1 mm |
C1 mm |
H1 mm |
E1 mm |
|---|---|---|---|---|---|---|---|---|---|---|
| 21 AL | 1 | 30 | 50 | 165 | 235 | 70 | 60 | 175 | 150 | 300 |
| 22 AL | 3 | 60 | 85 | 205 | 305 | 110 | 105 | 225 | 210 | 380 |
| 23 AL | 5 | 60 | 85 | 250 | 350 | 110 | 105 | 260 | 275 | 450 |
| 24 AL | 10 | 65 | 95 | 310 | 380 | 85 | 105 | 330 | 310 | 480 |
| Type | max. Content ca. [ L ] |
Weight ca. [ kg ] |
Holding Time LN2 ca. [ d ] |
Evaporation rate LN2 ca. [ L/d ] |
|---|---|---|---|---|
| 21 AL | 1 | 1,6 | 5 | 0,2 |
| 22 AL | 3 | 3,1 | 7 | 0,4 |
| 23 AL | 5 | 4,4 | 12 | 0,4 |
| 24 AL | 10 | 6,6 | 16 | 0,6 |
Safety advises and regulations
- always wear protective glasses and protective gloves
- national regulations for laboratories
- company- internal regulations
- safety regulations for handling with liquid gases
- ADR regulations
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ManufacturerKGW-ISOTHERM
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Country of OriginGermany
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Capacity (L)1, 3, 5, 10
-
Type21 AL, 22 AL, 23 AL, 24 AL
Dewar flasks made of glass
All Dewar flasks manufactured by KGW-ISOTHERM are made of borosilicate glass 3.3 DIN / ISO 3585 made by DWK or Schott Tubing. They are manufactured in compliance with the "Pressure Equipment Directive", Directive 97/23 EC, (N4 with Annex 1) and DIN EN ISO 16496 "Vacuum Insulation Equipment".
Structure and function of a Dewar flask out of glass
Dewar flasks made of glass are double-walled vacuum-insulated containers. They are used to thermally insulate a stored product (LN2, CO2 or other coolant) from the ambient temperature. Dewar flasks consist of an inner and an outer bulb, which are fused together at the top of the neck opening. The space between the inner and outer pistons is vacuum insulated to prevent thermal contact between the products stored in the Dewar with the ambient temperature (contact heat). In addition, Dewar flasks made of glass are equipped with a silver coating in the vacuum space in order to minimize heat radiation. Best insulation can be achieved by reducing both contact heat (vacuum) and radiation heat (silvering).
For security and work safety reasons, Dewar flasks made of glass always have to be installed in a protective enclosure. This protective cover can be made of sheet metal, aluminum, stainless steel or a transparent PU coating.
All standard glass Dewar flasks only may be used up to a maximum overpressure of 0.1 bar. Higher working pressures on request.
Complete or partly silvered plating’s and their influence on the evaporation rates
Regarding silvered glass Dewar flasks, a distinction has to be made between full silver plating (standard), silver plating with viewing stripes and unsilvered - transparent (customized special design). The lowest radiation losses (heat radiation) are obtained when having the full silver plating. Thus also the lowest evaporation rate / best static holding time of the stored refrigerant are reached with full silver plating. By attaching a viewing stripe in the silver layer, you change the reflection of the radiant heat and therefor also the insulation performance. The bigger a viewing stripe is or the more viewing stripes are incorporated in a silver plating, the greater is the loss of energy of the refrigerant stored in the Dewar vessel. The diagram shows the evaporation rates of liquid nitrogen in a Dewar flask type 15 C, 1.5 liter capacity with different kind of silver layings.
