Ultrasonication Saves Energy and Costs

Switching from conventional homogenizers, hydrodynamic mixers and agitated mills to ultrasonic cavitational processing adds both cost savings and makes processing environmentally friendly.

Due to the recent and continued rise in energy prices energy consumption has a direct and substantial effect on the processing costs of materials, such as inks, coatings and biodiesel.

Hielscher ultrasonic devices use less energy than traditional mechanical systems and achieve superior processing results. Therefore, changing from rotor-stator-mixers and high pressure homogenizers to ultrasonication saves significant electricity. This can translate into substantial cost savings over the years .

Frictional Heat is Unused Energy

Conventional systems loose energy to frictional heat. High pressure pumps for high pressure homogenizers, as well as high-shear blade mixers and agitated bead mills create high turbulence in the liquid as it is processed. This turbulences cause friction between the liquid particles and between the liquid and the agitating parts of the equipment. The friction converts input energy into frictional heating. This part of the input energy is lost, as it does not generate any dispersing, homogenizing or milling effect.

Much like the comparison between a conventional light bulb and a fluorescent bulb, the conventional converts much of the energy to heat. Therefore it requires more energy to provide the same level of light.

In case of conventional mixing systems, the frictional heating makes additional energy necessary for cooling the liquid during processing.

Hielscher ultrasonic devices have a very high energy efficiency in converting electricity into cavitation within the liquid. within the liquid. The overall energy efficiency of the industrial ultrasonic devices is approx. 80-90% from the power plug into the liquid (click at the image above to enlarge the chart). More important, the cavitational forces put a lot of stress onto the particles. That is why typically less energy is required to obtain a good dispersion, emulsion or a lower particle size. Hielscher Ultrasonication does create frictional heating, although at a much lower ratio than standard mechanical mixing. This lower ratio translates into additional efficiencies by requiring less energy to provide the same level of dispersing or homogenizing and in turn reduces the energy required for the cooling of the processed liquid.

Example: Biodiesel Processing

In particular in the processing of alternative and sustainable fuels, such as biodiesel, energy consumption and the conservation of such is extremely important. The electricity used for manufacturing the "green" fuel has a direct impact on the fuels overall energy and CO₂ balance.

The chart to the right (click for larger view) shows a comparison between ultrasonic cavitation, high-shear mixing and hydrodynamic cavitation. Using Hielscher ultrasonic devices for the processing of biodiesel requires approx. 1.4kWh/m³. To achieve a similar result using hydrodynamic magnetic impulse cavitation, requires approx. 32.0kWh/m³. High-Shear mixing requires approx. 4.4kWh/m³. This means, that hydrodynamic impulse cavitation requires approx. 23 times more energy and high shear mixing approx. 3 times more energy than Hielscher ultrasonic devices to provide the same throughput. This leads to significantly higher annual electricity costs. This is a major cost of ownership factor that must be evaluated when investing into a processing technology.

Change Made Easy

Hielscher ultrasonic devices can be easily tested for their process efficiency at smaller scale. Typically, the UIP1000hd (1kW) is used for the process development for flow rates from 0.5L to 1000L per hour. At this scale, the processing efficiency can be optimized by varying the amplitude, pressure and flow rate. As a result, you will get the specific energy requirement for your process. Hielscher ultrasonic devices allow for a linear scale up, so that the specific energy requirement remains constant at any scale. By this, you know the equipment power needed for a any processing capacity as well as the annual electricity consumption.