The Institut für Mikrotechnik Mainz in Germany (IMM) has developed a flexible system that evenly distributes a liquid flow to six different micro mixers without the need for active flow regulation.

The liquid distribution system is operated with selected impinging jet micro mixers while specially adjusted separation layer micro mixers serve as flow resistance.
For the first time such a system has been successfully applied to an organic synthesis reaction -- that of acetic acid-n-butylamine. The prototype achieved a total yield of 88percent and a product purity of up to 99percent.
Increasing throughput by scaling-out or numbering-up sounds simple in theory -- many micro reactors or mixers are simultaneously connected until the desired output is achieved. However, in practice this concept soon reaches economic limits because as the number of reactors increase, the cost of control engineering needed to manage them rises rapidly too.
IMM's liquid distribution system simplifies process control in micro process engineering. Distributing, for example, three components which are to be mixed to six micromixers, requires only three pumps. Conventional systems require 18 pumps. The distribution of the liquid is only controlled by the mixers' pressure loss (about 120millibar).
With precisely manufactured micromixers with equal pressure loss, deviations of the liquid distribution remain below ive per cent. This good result was achieved by careful the choice of material together with both optimisation of design and the production process.
Further versions of the liquid distribution system are currently under development. These not only allow the use of separation layer micro mixers, but also combinations with other micro components.
IMM has also launched a micro structured gas heater (MSGH) for combustible or explosive media. A clear separation of the space containing the medium from the heating elements allows safe heating and overheating of process gases, gas mixtures or gas/vapour mixtures.
Its uses range from laboratory to small industrial applications in the field of catalytic reactions, or in test plants for exhaust gas catalytic converters.
The MSGH has 50 cubic centimetres of ctive volume at a heat transmission surface of 0.2 square metres and outside measurements of 250x80x100mm (Fig.1). Therefore, compared with conventional gas heaters, the MSGH is very compact thanks to micro structures in the heat transmission zone. According to IMM it offers a clearly improved ratio of transmitted power to structural volume.
The process gases flow over micro structured channels on several levels. Conventional eating cartridges electrically temper block structures located in between. Diffusers on the front let the medium flow in and out. The heating allows a transmission power of up to 4kW and can be adapted depending on the desired power density. The MSGH is designed for an operating temperature of 750°C, a pressure stability of up to 5bar and a gas through-put of 10 cubic metres per hour.
Made of stainless steel, the MSGH is easily scaleable and with conventional clamping ring connections it can easily be integrated into stationary plants.