(Vacuum/pressure) nutsches Merto-Fil

The mixture from the feed tank is filled into the (vacuum) pressure nutsch and then pressed through the filter medium. The resulting filtrate enters the filtrate receiver, where it can be observed through a flow-through sight glass. If vacuum filtration is used, the necessary negative pressure is created with the help of a vacuum pump. It is important to avoid an excessive vacuum, as the vapour pressure of the filtrate must be taken into account. This can be achieved by incorporating an adjustable vacuum reducing valve.

In order to optimally utilise the full performance and specific characteristics of our (vacuum/pressure) nutsche filters, it is possible to combine the filtration process with a washing process. This process serves either to recover the valuable filtrate almost loss-free or to clean the filter cake from adhering impurities from previous reactions. In this process, a steady supply of washing liquid is fed through a ring brewer tube, which flushes the solids one or more times as required.

During the washing process, the solid residues can be effectively mixed with the washing liquid using an agitator. Once the washing process is complete, the washing liquid is either sucked out or squeezed off and the cleaned solids are discharged.

Also for extraction, i.e. to isolate individual components from the mixture with the help of a suitable solvent, effective nutsch filters are available (under vacuum or pressure). For this purpose, the mixture of substances is placed on the filter surface together with the solvent. Mixing by means of an agitator reduces the need for solvent and effectively shortens the separation times.

Our (vacuum) pressure nutes prove to be suitable equipment for the working process of batch crystallisation. In this process, separation is carried out by means of contact or vacuum cooling. When contact cooling is used, heat exchange takes place through a double jacket (special design), whereas with vacuum cooling, cooling is achieved through expansion evaporation. Regardless of the method chosen, the additional use of stirring leads to an improved distribution of heat. This has the effect of keeping the crystal particles in a suspended state, which additionally increases the efficiency of the process.

Since the feed chamber is located in a closed vacuum housing, the (vacuum) pressure nutsch can also be used partially as an agitator dryer according to one of the previously mentioned methods. If such an application is intended, it is possible to attach a heating device to the cylindrical part of the feed chamber. The agitator ensures continuous mixing of the dry material. To accelerate the drying process, superheated steam, hot air or inert gas can be passed through the filter cake.