Ultrasonic Homogenizers for Liquid Processing

• Lab
• Bench-Top
• Production

Hielscher offers a wide range of ultrasonic lab homogenizers (50 to 400W) to homogenize samples in beakers, test tubes or vials. Flow cells and flask adapters allow for more complex setups in the laboratory. For the sonication of closed vials, we offer the VialTweeter.

Bench-top homogenizers (0.5 to 2.0kW) are used for application research, scale-up work, pilot studies, process optimization or smaller batch processing. These programmable ultrasonic devices can be combined with flow cell reactors and pumps for in-line processing.

For high volume in-line processing or batch processing, we offer high-power ultrasonic probes (4 to 16kW). In commercial installations, these can run in clusters to process several hundred tons per hour. Sanitary designs, and multi-feed flow cells are avaible to adapt to your processing needs.

Ultrasonic Processes and Applications

Ultrasonic Blending

While tank agitators may blend easily miscible liquids of similar viscosities, liquids of different viscosity or more viscous liquids may require high mechanical shear for fast and complete blending. Our ultrasonic devices can easily blend two or more liquids in-line. For this, the liquids would be combined just before the ultrasonic flow cell reactors. Read more about blending!

Ultrasonic Homogenizing

Hielscher ultrasonic homogenizers are very effective in achieving a small and uniform globule or particle size when processing powder/liquid or liquid/liquid formulations. The high hydraulic shear forces generated by ultrasonics break agglomerates, droplets and cell tissue into smaller fragments and produce a uniform fine-size product. Our range of homogenizers covers any processing volume from lab vials to bulk production size. Read more about homogenizing!

Ultrasonic Deagglomerating

Hielscher ultrasonic homogenizers break powder agglomerates in liquids that conventional agitators and high shear mixers cannot break. The high cavitational shear disperses and homogenizes agglomerated particles resulting in a higher specific surface area. Hielscher ultrasonic homogenizers can easily be integrated in-line or in a batch. Read more about deagglomerating!

Ultrasonic Dispersing

For almost every product, it is important that particles are separated from other particles in order to enlarge the particle surface area and to achieve an uniform distribution. Even dispersions can easily be achieved by ultrasonication. Hielscher’s ultrasonicators are widely used for the production of fine-size dispersions in the micron- and nano-range. Read more about dispersing!

Ultrasonic Emulsifying

When mixing immiscible liquids into an emulsion, droplet size and distribution are a key factor for the stability of the emulsion. Ultrasonics can create very fine size droplets and narrow size distributions. In most cases, our ultrasonic mixers can achieve submicron droplets when preparing emulsions in a batch or in-line. Different from high pressure homogenizers, the high shear produced by our ultrasonic devices will emulsify even high viscosity liquids, such as heavy fuel oils (HFOs). Some formulations may require emulsifiers or stabilizers to be added. In this case ultrasonicators help to mix the emulsifier uniformly. Read more about emulsifying!

Ultrasonic Dissolving

Ultrasonic homogenizers are an efficient and reliable means for the solubilizing of various materials, such as salt, sugars, syrups, resins and polymers. The high-speed liquid jets created by the ultrasonic cavitation increase mass transfer at boundary layers. This results in faster and more complete dissolving and leaching of particles or high viscosity liquids. Read more about ultrasonic dissolving!

Ultrasonic Particle Size Reduction

Hielscher ultrasonic processors can break agglomerates, aggregates and primary particles of various materials, such as pigments, metal oxides, or crystals. Ultrasonics can achieve very uniform and narrow particle size distributions with little to no variation between batches. Ultrasonic milling is most efficient in the range below 500 micron to sub-micron and nano-size range. Our ultrasonic reactors can handle high solids loads and high slurry viscosities. The final particle size will depend on the hardness of the product. Read more about particle size reduction!

More Ultrasonic Processes

Ultrasonic Particle Surface Cleaning

The surface of powder particles is a key factor for the interaction with the surrounding liquid. It is at such solid/liquid phase boundaries, where dissolving, chemical reactions or catalytical activity take place. Ultrasonic homogenization increases the exposure of particle surface to the liquid phase by uniform deagglomeration and particle size reduction. During catalytic and chemical reactions, the particle surface can be blocked by residue deposition, boundary layer formation, oxide layers and fouling. Ultrasonic cavitation causes high-speed liquid jets, high hydraulic shear and inter-particle collisions resulting in particle surface cleaning. Hielscher ultrasonic devices can be used in a batch or in-line to remove contaminations from particles in liquids.

Ultrasonic Agitation

Stirring is an often-underestimated process and requires reliable equipment, especially for increasing viscosities and volumes. Conventional agitators such as paddle mixers or rotor-stator mixers are limited by various factors, including viscosity and scalability. Therefore, high power ultrasonicators are the right choice for your mixing process due to their advantages in higher through-put, time saving, lower operational costs, safe operation (no moving parts) and simple maintenance.

Ultrasonic Hydrating

When mixing dry powders, such as, pigments, thickeners or gums with liquids, the powder particles tend to form agglomerates, lumps or so-called “fish-eyes” (partially hydrated powder with a dry powder core). Agitators and stirrers will wash the surface of such agglomerates, only. This results in long mixing times and poor product quality. Ultrasonic mixing breaks agglomerates and lumps leading to an agglomerate-free solution. Furthermore, sono-chemical effects are well known to activate the particle surface area, which leads to advantages such as faster reactions and enhanced product quality.

Ultrasonic Sample Preparation

For measurements by analytical instruments (e.g. HPLC, atomic spectrometer, etc.), generally most samples have to be liquefied. If the sample is soluble, the solute (such as sucralose, salts, e.g. in powder or tablet form) can be dissolved in a solvent (e.g. water, aqueous solvents, organic solvents etc.) resulting in a homogeneous mixture, composed of only one phase. The dissolving process can be carried out by manual or mechanical stirring, which is time-consuming and inefficient. Related problems are sample losses due to manipulation or lacking reproducibility by random errors and uneven mixing.

Ultrasonics for Chemical Activation

To initiate a chemical reaction, energy is required. The so-called activation energy is the amount of energy required to initiate a reaction and carry on spontaneously. By the input of ultrasonic energy, chemicals reaction can be initiated as attractive forces are overcome and free radicals are created. Typical chemical reactions that benefit from ultrasound are sono-catalysis (e.g. phase transfer catalysis), synthetic organic reactions, sonolysis as well as sol-gel-routes. Furthermore, ultrasonic forces create highly reactive surfaces, which is an important technique to increase catalyst activity.

Ultrasonic Shear-Thinning

The phenomenon of decreasing viscosity under increasing shear forces is termed shear thinning or thixotropic. The decrease of viscosity is of significant importance when the particle load of a medium should be modified. To achieve a higher solid load, in the first step viscosity must be lowered. After viscosity reduction, solids can be added and dispersed in the medium. High-shear forces created by ultrasonic cavitation cause shear-thinning and outstanding dispersing results. This application is mainly integrated before spray-drying or spray-freezing to increase the capacity of the spraying process or to influence the rheology of thixotropic material, e.g. polymers.

Ultrasonic Wet Milling

Milling and particle size reduction are key processes in many industrial branches such as for paint & coatings, inkjet ink & printing, chemicals or cosmetics. The ultrasonic milling technology is proven for its reliable size reduction and dispersion in the micron- and nano-size range. Its unbeatable strength over bead, ball, and pebble mills lays in the avoidance of any milling media (e.g. beads/ pearls) that contaminate the final product due to abrasion. In contrary, ultrasonic milling is based on inter-particular collision – this means the particles to be milled are used as grist. Therefore the time-consuming cleaning of milling media is not any longer an issue. High viscosities and large volume streams can be processed resulting in a high quality product. For the integration into an industrial process line, Hielscher supplies the suitable solution: clusterizable systems, easy integration/ retrofitting, low maintenance, simple operation and high reliability. Read more about wet milling and fine grinding!

Ultrasonic Extraction and Cell Lysis

Cell disintegration or lysis is a common part of daily sample preparation in biotech laboratories. The goal of lysis is to disrupt parts of the cell wall or the complete cell to release biological molecules. The so-called lysate can consist in e.g. plasmid, receptor assays, proteins, DNA, RNA etc. Subsequent steps after lysis are fractionation, organelle isolation or/and protein extraction and purification. The extracted material (= lysate) has to be separated and is subject to further investigations or applications, e.g. for proteomic research. Ultrasonic homogenizers are a common tool for successful cell lysis and extraction. As the ultrasonic intensity can be leveled by adjusting the process parameters, the optimal sonication intensity – varying from very soft to highly intensive – can be set for each substance and medium. Read more about extraction and cell lysis!

Ultrasonic Microbial Inactivation

Microbial inactivation is a key process in food processing. Due to the increasing demand for fresh, mild processed food, the industry follows the customers’ demand by replacing thermal preservation by milder processing methods. Ultrasonication is a non-thermal technique that allows for the inactivation of microorganisms at sublethal temperatures resulting in a better preservation of the sensory attributes, nutritional and functional properties of the product. As microorganisms are the main cause for food spoilage, the preservation technique must be targeted towards them. The advantage of sonication is the full control over sonication intensity and thus the adaptability to specific types of microbes and the product. Read more about microbial inactivation!

Ultrasonic Degassing

In many liquid products, dissolved gas such as air, oxygen or carbon dioxide, causes problems for down-stream processes or product quality. Dissolved gas can result in corrosion, foaming, the formation of micro-bubbles or microbial growth.
Under ultrasonic irradiation, the dissolved gas is extracted into the vacuum of cavitation bubbles (vacuum degasification). The gas filled bubbles subsequently float to the top and can thereby be removed. The gas content of a liquid can be decreased rapidly below natural equilibrium at atmospheric pressure using ultrasonic degassing. Read more about degassing!

Ultrasonic Removal of Micro-Bubbles

Suspended micro-bubbles in liquids and slurries are a significant quality issue for many products, as such bubbles can result in product impurity, microbial growth, haze in coatings, mechanical instability, or uneven printing results by gas-containing inkjet ink. Ultrasonic waves propagating through the liquid force suspended bubbles to merge into bigger bubbles that will float to the top and can thereby be removed. Ultrasonication helps bubbles to move through the liquid, e.g. water, oil or resin, leading to a faster and more complete deaeration. Read more about the removal of micro bubbles!

Ultrasonic Defoaming

In many industrial processes, such as fermentation, digestion or chemical processes, foam causes great problems as it makes process less controllable. Mostly, foam is an unwanted by-product, which must be removed. Commonly used anti-foaming chemicals are expensive and contaminate the final product. In contrast, highly intense ultrasound waves (sono-defoaming) break the foam without contamination. The destruction of foam is a soft, low energy ultrasonic application. Specially designed plate sonotrodes create high amplitude air born waves, which destabilize the bubbles in the foam so they collapse. This can be achieved in a few seconds and does not have any residual effects. Read more about defoaming!

Ultrasonic Heating

Although heating is mostly not the main purpose of sonication, the side effect of heat generation in the treated medium should not be neglected. Controlled heating is advantageous as many processes are improved by heat. During many processes, e.g. preservation or chemical reactions, the ultrasonic treatment is purposely supported by elevated temperature, known as thermo-sonication. For heat-sensitive materials, targeted cooling during the sonication secures stable temperatures during ultrasonic processing. By implementing ice baths, flow cells with cooling jackets and integrated heat exchangers in the setup, Hielscher offers the solution for your individual targets.

Ultrasonic Stabilization

High power ultrasound contributes to mechanical as well as microbial stabilization. Ultrasonically generated high shear forces provide an extremely fine mixing so that inter-particle bondings are overcome and mechanical stabilization is achieved. The durability of the stability depends on the formulation: some emulsions and dispersions are self-stable due to the very fine and even homogenization, whilst other mixtures must be supported by the addition of stabilizing agents. If stabilizers are needed, ultrasound is a very reliable tool to mix the stabilizer into the mixture.
For biological and food-related products, ultrasound is dependable technique of microbial inactivation to achieve product stability and preservation. Ultrasonic microbial stabilization is a non-thermal preservation alternative that convinces by efficient microbial deactivation and only mild heat generation. Ultrasound has been demonstrated to be very effective on the destruction of food-borne pathogens, like E.coli, Salmonellae, Ascaris, Giargia, Cryptosporidium cysts, and Poliovirus.

Ultrasonic Particle Surface Functionalization

The structure of a particle’s surface is important for the particle characteristics. The specific Surface area of a particle becomes larger in correlation with the reduction of the particle size. Thus, by decreasing particle size, the surface properties become increasingly prominent – especially during nanonization. For the usage of such materials, surface characteristics are as important as the properties of the particle core. This means that the functionalization of nanomaterials enables a broad range of applications such as polymers, nanofluids, biocomposites, nanomedicines, and electronics. This makes the size reduction, deagglomeration, and functionalization an essential step in particle treatment. Hielscher ultrasonicators are widely used for the treatment of micron- and nano-particles in order to mill, deagglomerate, disperse and modify their structure. By the modification of the particle surface, an unwanted aggregation of particles can be avoided. In downstream steps, the ultrasonically modified particles can be mixed into composites, where sonication achieves a homogeneous distribution within a matrix. This is very important for manifold industrial applications regarding long-time stability or mechanical properties of hybrid materials.

Ultrasonic Erosion Testing

Cavitation erosion resistance is an important aspect of material durability and lifetime. To ensure material functionality, erosion propensity and material fatigue must be tested for quality assurance. Erosion resistance is of high relevance for materials used in demanding environments such as ship propellers, (marine) coatings, pumps, engine components, hydraulic turbines, hydraulic dynamometers, valves, bearings, diesel engine cylinder liners, hydrofoils, and in internal flow passages with obstructions etc. To perform cavitation erosion testing in accordance with ASTM Standard G32-92, controllable and reproducible ultrasonication is inevitable. Hielscher ultrasonic devices can be used for the direct and indirect erosion testing of samples. The same ultrasonic equipment can be used for both, the direct and the indirect tests. During direct testing a specimen is mounted to the sonotrode, whilst for indirect erosion testing the specimen is fixed in the beaker. The erosion tests can be carried out under fully controlled environmental conditions and in almost every fluid. By adjusting the ultrasonic intensity, the erosive power can be adapted to the test requirements. Read more about erosion testing!

Ultrasonic Wire and Cable Cleaning

Endless materials such as wires, cables, tapes, rods, and tubes have to be cleaned of lubricant residues before they can be further processed downstream, such as galvanizing, extrusion or welding. Cleaning of endless materials is often the bottleneck of the production line. Hielscher Ultrasonics offers an unique ultrasonic cleaning process for efficient inline cleaning, which can handle even high throughput speed. The effect of the cavitation generated by the ultrasonic power removes lubrication residues like oil or grease, soaps, stearates or dust. In addition, the pollution particles are dispersed into the cleaning liquid. By that, a new adhesion to the material to be cleaned is avoided and the particles are flushed away. Advantages of ultrasonic cleaning at a glance: proven & reliable, efficient, environmental-friendly, less or none chemical cleaning agents, plug-and-play, modular systems, simple operation, low maintenance, 24/7 operation, small footprint, retrofittable, customizable. Read more about continuous strand cleaning!

Ultrasonic Sieving and Filtration

Separation of particles by size difference requires agitation of the screen or mesh. Ultrasonic agitation for sieving and screening is a proven tool, which increases sieving capacity and saves time as powders are enabled to pass the sieve faster and more complete. The result is a better final product quality with less material loss due to incomplete separation – and all within a shorter processing time. Read more about sieving and screening!

Ultrasonic Water Treatment

The control of bacteria and algae growth in water is for many industries a highly relevant upstream- or downstream-process for production. Powerful ultrasound waves are known for their effects on cell structures causing cell lysis and cell death as well as for their cleaning capability due to mechanical impact.
Furthermore, tanks, barrels, vessels and even filters can be successful cleaned from biofilms, residues, and debris in a very simple but efficient sonication step. Ultrasonically generated mechanical vibrations and cavitational shear forces remove the contamination. In general, cleaning agents are not necessary and the removed residues can be easily flushed away.