A patented pump stand for completely automatic and environmentally friendly vacuum distillations. The solvent recovery yield of almost 100 % guarantees very low emission rates to the environment. The rotary evaporator flask is connected directly to the Hold-Back-Pump. After the heater bath and the rotary drive are prepared for the process the Hold-Back-Pump is switched on to produce the vacuum needed. The evaporation pressure is reached automatically for any solvent or solvent mix without a vacuum controller and the distillation is processed automatically without interruption no matter how many different solvents are being distilled. The fractions are collected in a container of your choice at atmospheric pressure.
Hold-Back-Pumps operate without a controller by bringing physical condensation laws into practice. The solvent itself contains the necessary information for automatic pressure regulation. The boiling point of the solvent, or solvent mixture need not be known, monitored or controlled externally. The product is concentrated in just one evaporation cycle, quickly and without loss since the process is maintained at the optimum boiling point. There are no environmentally dangerous emissions, since the whole process is executed in a closed circuit.
Hold-Back-Pumps guarantee a fully-automatic process without any manual adjustment or regulation and without time consuming and costly electronic controller. The distillation result is considerably better and more economically sound than when using a diaphragm pump system with control valve or speed control.

Advantages:

• Independent process cycle
• Solvent recovery rates close to 100%
• Economical alternative to regulated vacuum pump systems
• Environmentally friendly
• Little emission
• Low noise level
• Easy to service design
• Available for different mains supplies
• Pressure indication by optional sensor

Application range:

• For optimised destillation of solvents and solvent mixtures down to 10 mbar