Evaporators

Evaporator with motorized lift

A Cost Effective and Flexible Solution

When a larger number of samples must be processed the VLM evaporators are an inexpensive alternative to rotary evaporators and concentrators.  The evaporation of the solvent is accelerated by gassing with nitrogen which is a very gentle method for oxidation sensitive samples. The built in metal block thermostats are used to compensate for evaporation by maintaining the constant temperature of the system.

The evaporator system is equipped either with a motorized lift or with the evaporator unit with a manually height-adjustable stand. Further the part of the system is the gas dosing unit and the metal block thermostat QA, EC, LS or VIS. This image shows the version of evaportaor with a telescopic lift where the replacement of the heating blocks or samples is very convenient.

When turning the gas dosing unit of EVA-lift 180° the stainless steel needles or Pasteur pipettes (adapter plate required) can be easily inserted from above into the silicone mounts. In case of the manual version of this evaporator the complete gas dosing unit can be removed and stainless steel needles can be inserted from above as well.

As accessories VLM offers cabinets which can be connected to the laboratory ventilation system. Furthermore it is possible to pulse the flow of nitrogen and to switch off the gas dosing after a preselected time.

Specifications subject to change.


The cost effective version with the stand

A Typical Evaporator System Consists of:

  • Evaporator with gas dosing unit and the motorized lift or simple stand unit
  • EC heating tank thermostat for removable heating blocks, max. operating temperature 130°C or 210°C.
  • 1 heating block for 48, 24 or 16 standard test tubes Ø 16 mm, slot depth 65 mm
  • 48, 24 or 16 stainless steel needles coated with PVDF (optional) Microtiter plates: 96 tips
  • PU hose with adapter for connecting to the gas fittings
  • Optional adapter plate for use with Pasteur pipettes or pipette tips (optional)
  • Optional gas pressure regulator with gauge

EVA-VIS with up to 72 probes






VLM Evaporator for 1 microtiter plate
VLM Evaporator with lift for 1 microtiter plate

The EVA-VIS - Evaporation with Visual Inspection of Residual Volume

The left figure shows the standard version of the device with 3 heating blocks for 72 standard 16 mm test tubes.

In order to monitor the decreasing level of test liquid the heating blocks are placed in longitudinal slots and illuminated with the handy fluorescent lamp. Under these conditions it is possible to concentrate the samples to a residual volume.

The nitrogen supply for the rear heating blocks can be opened at different times. The largest part of the solvent evaporates already, because in this phase is not the observation of the liquid level is required.
After removal of the front block located behind the blocks are pulled forward to stop the evaporation in the final phase. Thanks to this time-saving approach allows the VLM Evaporator VIS-high sample throughput.


VLM provides heating blocks for the standard test tubes, Eppendorf tubes, chromatography vials and round-shaped flask.

The gas dosing unit is divided into three devided chambers in which nitrogen is seaprately introduced. By means of the valve screw it is possible to adjust the flow rate for each of the 72 samples individually. With a special adapter plate the stainless steel tubing can be replaced with the glass Pasteur pipettes.


The thermostat is equipped with a VLM JUMO microprocessor controller which ensures precise temperature control of the samples or for the accurate compensation of evaporative cooling.


Evaporator systems with stand or lift for microtiter plates

The nitric acid distribution units for microtiter plates are accordingly equipped with 96 stainless steel cannulas. These are covered with PVDF shrink tubing to protect the exterior surfaces from corrosion if acid-cleaving reagents are used.

Unlike the nitrogen diffusers of the standard versions with individually adjustable outlets, the outlets for the microtiter plates are all open. However, the nitrogen flow can be adjusted with the side-mounted ball valve.

For certain applications, the room temperature is sufficient to evaporate the solvents with nitrogen. Of course, it can be e.g. The tripod can be obtained individually without a metal block thermostat.

The nitrogen distribution units of the EC Evaporators for 24 samples and for microtiter plates are each exchangeable. A lift can therefore be used for EC 1 metal block thermostats and corresponding heating blocks as well as for the sample concentration of 1 microtiter plate after changing the nitrogen distribution unit.