OHS Overhead Stirrer

The OHS Overhead Stirrer offers powerful mechanical stirring, at the same time it is small sized and low-weighted allowing flexible, lab-stand-free mounting on GL25 glassware.

In joint use with the xelsius Reactor Workstation up to 10 OHS Overhead Stirrers are intergrated into the xelsius control software environment via the OHS XConnect Box.

For single unit use or standalone use the OHS Overhead Stirrer is controlled with the OHS Interface.


KEY FEATURES

  • Compact and durable design
  • Brushless DC-servomotor:
    High torque & constant rotational speed
  • Stirring rate from 20 to 1000 rpm,
    Stirring rate control in 1 rpm increments,
    Anti-clockwise and clockwise rotation selectable
  • Lightweight, lab-stand-free experimental setup
  • Magnetically coupled stirring shaft
    for quick exchange and easy cleaning
  • Height-adjustable stirrer blase position,
    Second slideable stirrer blade optional
  • Multifunctional 4-port cap
  • High chemical resistance


SPECIFICATIONS

  • Continuous nominal torque: 106 mNm,
    Maximal nominal torque: 230 mNm
  • Stirring rate: 20 – 1000 rpm,
    Stirring rate accuracy: ± 1%
  • Mounting: self-supporting installation
  • Wetted material: PTFE or Hastelloy
  • Control options:
    Hardware-based control for single-unit use,
    Software-integrated control for multi-unit use
  • Connection: LEMO 5 pole plug
  • Power supply: 24 VDC, 17 W
  • Safety: Overheat protection



OVERVIEW

The OHS Overhead Stirrer is equipped with a brushless DC servomotor and a planetary gear to ensure stable and reliable operation in laboratory applications. The servomotor (integrated speed controller, 4-pole technology, continuous nominal torque 106 mNm) maintains a constant rotational speed under varying loads for reproducible mixing results. The planetary gear (6,6:1, efficiency 92%, IP54) provides  high torque transmission with low backlash, enabling effective and powerful stirring of both low- and high-viscosity fluids.

The stirrer shaft is connected to the drive unit via a magnetic coupling, which makes disassembly uncomplicated, allowing quick exchange of stirrers and easy cleaning.

The stirrer blade position is height-adjustable within a range of 40 mm by loosening and tightening a knurled screw along a guide rail at the lower casing. For mixing high-viscosity fluids a second stirrer can be installed, this slidable stirrer blade can be freely positioned along the stirrer shaft, enhancing stirring performance.

The 4-port cap, compatible to GL25 thread glassware, allows the integration of tubes (gassing, inerting and dosing), septi (sampling) and sensors (monitoring and temperature control) using fittings (UNF 1/4” 28 threads) and ferrules with 1/16” (Ø = 1.6 mm) and 1/8” (Ø = 3.2 mm) feedthroughs.

The joints between stirrer casing and 4-port cap are gas-tight, additional a PTFE rotary seal between mount and stirrer shaft is incorporated. Thereby solvent loss is excluded when synthesis are carried out at reaction temperatures close to the solvents boiling point.

The overhead stirrer is mounted on top of the 4-port cap via a screw-in connection, this freestanding installation makes laboratory stands or mounting brackets obsolete.

There are hastelloy metal and PTFE coated stirrer shafts available. Employing latter ones makes PTFE the sole wetted material, as stirrer blades are also made from PTFE. Thereby a high chemical resistance is achieved and potential metal ion contamination (as observed for uncoated stirrer shafts) is excluded.

OHS XConnect

The OHS XConnect links up to 10 OHS Overhead Stirrers and connects them with the xelsius reactrn workstation for centralized software-based control.

It enables individual stirring across 10 positions embedded into reaction profiles of the xelsius control software with defined stirring rates for each reaction segment.

Stirring rates are controlled from 20 to 1000 rpm in 1 rpm increments, clockwise and anti-clockwise rotation is selectable.

OHS Interface

The OHS Interface is designed for single-unit use with the xelsius reactor or standalone use of the OHS Overhead Stirrer.

Stirring rate, rotation orientation and timer function are set with a rotary encoder, these settings are visualized on a LCD display.

Stirring rates are controlled from 20 to 1000 rpm in 1 rpm increments, clockwise and anti-clockwise rotation is selectable.