By Mark Franco

Dispersion

Dispersion is simply described as the blending of two or more substances which may be immiscible. What this means is that by the way of dispersion, an ingredient (which can be any of the three states of matter -gas, liquid or solid) is transferred into an incompatible, encompassing substance (conventionally a liquid.)

Homogenization

It is only through dispersion that a blended fluid can be homogenized with no significant differentiation between the individual substances. In the industries of food production, pharmaceuticals and cosmetics/skincare, this homogenization effect on blended substances is called a mono-dispersion fluid. To obtain complete homogenization the items being mixed must be colloidal, which means the components must blend into individual dimensions of less than a micrometer.

Equipment to Obtain Colloidal Substances

It is through the use of high shear mixers in the dispersion process that mixtures and unique ingredients can become colloidal and experience complete homogenization.  This is done by using high shear mixers offering a concentrated input of energy that result in immense dispersion of items. Faster than conventional blending methods, the use of high shear mixers produce homogenized products quickly and efficiently.

Applications in the Cosmetic and Skin Care Industries

Dispersing and homogenization applications particularly apply to the industry of cosmetics and skin care. With a variety of creams, lotions, ointments and powders manufactured and featuring several traditionally immiscible substances (thickeners, perfumes, color additives and medicinal powders,) it means the processes of dispersion through a high shear mixer must create homogenization for fluid, consistent and complete products.

 Applications in the Food Manufacturing Industry

The food mixing industries are similar to the cosmetic business in that they each have to disperse incompatible ingredients through a high shear mixing process. Some products that undergo the dispersion process for homogenization are:

• Cheese Spreads

Cheese spreads are a combination of normal dairy cheese and other ingredients such as food coloring, salt, and additional flavoring. These items may not always blend together perfectly for a colloidal substance, meaning that the Dispersion and homogenization processes is needed.

• Salad and Pasta Dressings

A common form of dispersion and homogenization in dressings is in vinaigrettes. The blend of oil with other ingredients can cause separation but through these processes, it can create one fluid and consistent food product.

Applications in the Pharmaceutical Industry

In pharmaceutics, it requires similar textures for substances as those in the skincare industry. Items may need to be in powdered form or used as a topical gel, meaning that the applications of dispersion and homogenization are often implemented during the mixing and batching processes.

Homogenizing/Dispersing Applications

In the industries of food production, pharmaceuticals and cosmetics/skincare we often see the application of dispersion and homogenization used to manufacture a complete and functional product. It is through these processes that food, medicine and skincare products remain consistent in texture, quality, color and in some cases, taste.

Agitators

A general term that describes a device that is complete with a power system, shaft, and impeller and used for agitating the contents of a vessel.

Apparent Viscosity

The viscosity (flow resistance) of a fluid at a specific sheer rate. Also refers to the consistency of the fluid at an arbitrary point on the stress-flow curve.

Axial Flow

The flow of fluid from the top to the bottom of the tank, parallel to the axis of the mixer shaft.

Coverage

The distance between the impeller and the surface of the fluid. It is an important part of the process because it is necessary to prevent vortexing.

Emulsion

A colloidal dispersion of two or more liquids which are un-blendable. The substances can be combined or mixed by suspending one inside the other, but they cannot be dissolved.

Flow

Refers to the measurement of the movement generated by the fluid that is being mixed. Shear and flow are usually inversely related, which means that a high flow may provide rapid turnover on the material, but it will produce lower levels of shear.

High-Shear Mixer

An industrial mixer that is designed for mixing materials where particle size reduction or breaking apart larger solids is necessary. The most common high shear mixer is a disperser. Most models work by using counter-current mixing to subject different materials to very high forces.

Impellers

The devices that actually contacts the materials and imparts energy from the motor to the material being mixed. There are different styles of impellers, but they are all the rotating components that provide the force to mix the fluids.

Lift

The system used to lift or move mixers in or out of a tank or drum. There are different systems, including air lift, winch lift, manual lift, and electric lift.

Low-Shear Mixer

A mixing process that uses the least amount of energy possible to still impart sufficient motion to the material. The impeller blades for low-shear mixing are designed for low drag and smooth flow.

Off Bottom

The space between the bottom of the impeller and the bottom of the tank. Different applications will have different requirements for this distance.

Radial Flow

Movement of the fluid from the center of the tank toward the walls, or perpendicular to the axis of the mixer shaft.

Reynolds Number

This number is used to calculate the flow and power draw in applications with higher viscosity levels and represents the magnitude of fluid motion or agitation. Simply put, it is the ratio of inertial to viscous forces.

Shear

Shear measures the stress produced on the fluid that is being mixed. It is the portion of the applied power that appears as drag on the blades, turbulence, velocity, etc.

Shear Dispersers

Mixers that are designed for liquid mixing operations in which it is necessary to reduce the particle size of one element or break apart a number of solids.

Side-Entry Mixer

Mixers that are added to a vessel through its side wall. These models usually have special seals to prevent materials leaking out through the mixer.

Top Entry Mixer

The mixer is placed in the vessel through the top. This is a common configuration and can be designed for open or closed tank usage.

Viscosity

A measurement of the “thickness” of a fluid or its resistance to being moved or deformed by shear stress or agitation. It is usually measured in CentiPoise (Cp) and shows what the internal fluid friction is actually like.

Vortex

A depression in the liquid surface as it swirls in the tank. It is usually undesirable because it pulls the fluid surface around the shaft until it contacts the impeller. This allows air to become part of the mix. “Vortexing” can significantly reduce the life of a mixer.

Category 1: Drive Motor

Drive motors on mixers need to be inspected weekly for vibration, dust, dirt and residue. Any of this left for long periods of time can cause the motor to overheat and shorten its long working lifespan.

Category 2: Gear Reducer

Weekly maintenance on the gear reducer includes looking for leaks, listening for unusual noises and cleaning the breather so it is clear.

Category 3: Pneumatic Filter-Regulator

Check the filter for dirt or plugging and drain the bowls as needed.

Category 4: Emergency Stop Button

Having a failsafe is very important which is why during the weekly inspections, it is vital to test the emergency stop button by pushing the button while mixer is running. This ensures it is working properly and the safety of workers.

Regular Maintenance on Mixers

To prevent erosion and to preserve the integrity of a mixer, qualified personnel will need to conduct weekly, monthly and semi-annually maintenance checks. Regular weekly maintenance falls into four easy categories and with these four categories it can be ensured that a mixer will last for decades.

Energy Consumption Factors

Several factors contribute to the energy consumption of industrial mixers. . First and foremost, the behavior of the substances being mixed in their raw states and how they react to other ingredients in the mixture can affect the unique levels of shear to be used on the mix. If the shear is inappropriately proportioned, it can strain the mixer and cause more energy usage.

Also humidity and temperature can play a role in energy mixing consumption due to how the substances thicken or thin due to temperature adjustments. Many substances and products can be temperature sensitive. An increase in temperature for the mixing process can cause thickening which requires more energy usage by the mixer.

Lastly, many mixers have designated properties for specific mixing applications. Should the wrong mixer be used in a batching project, it can result in inconsistent product as well as high energy usage as the mixer attempts to get through the project it was not designed for.

Mixing Methods to Save Energy

Mixing methods to conserve energy often come down to decisions of the processing engineer but certain mixers can work on high shear while performing quick and energy effective blending. One method of saving energy is to use the appropriate mixers on your mixing substances to receive the desired consistency and color. Another method to save energy in the mixing process is to convert to continuous mixing. Continuous mixing can save in energy consumption as well as provide easier drum/tank cleaning, more control and versatility of blending options.

Negate Energy Consumption Concerns

While more and more mixing companies are becoming concerned about being eco-friendly, the energy concerns of mixers can be negated through proper use of mixers and an in depth knowledge of the substances being blended. Choosing the correct mixer can help a company stay eco-friendly as well as cut production costs without compromising product quality.

Both of these industries choose to use stainless steel mixers and tanks due to the steel’s smooth surface, strong withstanding to industrial conditions, its neutrality and its easy to clean and disinfect nature. In fact, in the dairy industry stainless steel is used primarily due to its ability to be non-reactive to the lactic acids which form during the milk fermentation process and its quick and easy cleaning process.

Cleaning and Sterilization of Tanks

For breweries using stainless steel tanks, they often use a combination of three cleaning agents to ensure sanitary conditions. First, many commercial brewers recommend Caustic (sodium hydroxide.) This alkaline agent cleans and removes organics from the tank and mixer surfaces but if left on too long it can cause damage. To prevent damage, the second cleaning agents of Muriatic acid and Phosphoric acid are used. They are used to remove calcium and neutralize any after effects of using the Caustic solution. Lastly, to improve the sanitary surface finish, brewers use nitric acid to clean equipment.

Cleaning and the sterilization of mixing tanks in the dairy industry require eradication of all contamination that may stick to the surface of the stainless steel. To do this the surfaces must be disinfected with an in depth cleaning process. The tanks can be no higher than the reach of a typical person’s hand, making sure that all surfaces can be cleaned and reached. Some tanks come with sanitizing spray nozzles but occasionally the interior needs to be hand cleaned.

Sanitizing Fixed Equipment (mixers)

Some stainless steel items in the food industry cannot be cleaned in the same manner of tanks or removable parts. In the case of mixers or slicers, all of the removable parts must be removed and sanitized. The remaining (fixed) parts need to be cleaned with hot water and a detergent and then rinsed, air-dried and covered/sprayed with a sterile solution.

 Sanitary Conditions in Your Stainless Steel Mixers

Stainless steel is one of the most sanitary metals in the tank/ mixer market and by taking a page out of dairy and beer manufacturers’ books; you too can ensure the sanitary conditions of your stainless steel mixers and tanks.

Tank Designer puts the configuring and customizing of stainless steel vessels right in the hands of the customer.  It allows you to jump right in and systematically add your specs, from dish, cone, flat bottoms to a host of fittings, materials, and mixer mounts.  Special instructions can be documented at each area of the drawing.  While this is nice, the real advantage comes with an immediate tank price generated for your application.  No more waiting a week to get a quote to find that you need to wait another week to get a price because an option you picked was not very economical.  No working the night before a deadline and realizing that a spec changed and you have to guess how that is going to affect the cost.  In the past waiting a few weeks for a quote was not a big deal in the chemical manufacturing industry,  today, however,  with fierce worldwide competition waiting weeks could be the difference between success and failure.

Every detail of your custom tank is stated on an attractive pdf download ready for inclusion into your project submittal.  That information is stored on Mixer Direct’s cloud servers and can be pulled down by our engineers who are available to review each of the designs as you have need.  We are not trying to pawn our customers off on a half-baked web tool. Rather we want to couple first in the industry tech tools with first in the industry personal service.  We call it “Available Expertise” and with it we strive to give your business as much information about stainless steel vessels in the places where you most commonly look for it.

Of course every implemented idea gives birth to new dreams and desires, so stay tuned for a series of updates. As of now, we are pleased to be able to present to you the ability to get real time costing for your customized stainless steel mixing tanks.  Let us know what else you would like to see on future releases!

What Do Petroleum Mixers Do

In the petroleum industry, mixers are used on a range of products, including lubricants, asphalt, crude oil blends, and gasoline. Mixers must be able to stand up to heavier liquids and the rugged treatment they receive while working with these materials in refineries or pipeline applications.

Mixers are used to optimize heat transfers, dilute heavy crude oils, and maintain homogeneous results. This means that in asphalt applications, mixers will help prevent sludge from building up on the bottom and keep the head distributed uniformly. It will do the same for crude oil, but the mixer will also effectively blend the different types of crude oil and any additives that are necessary. And when it comes to gasoline, the mixer must prevent stratification and completely integrate all the liquids and additives.

What to Look For

Remember, effective, reliable mixing will lead to a much higher ROI/profit margin, so there are a few simple things you should look for in your industrial mixers. They should: eliminate sludge (water and debris buildup in the bottom of the tank), make it easy to predict blending outcomes, make heat transfers more effective, and provide energy savings.

There are a number of elements that will have an impact on the usability and longevity of your mixers, so be sure you carefully examine these factors:

• Energy Consumption – How much energy does it take to keep the liquids flowing around the tank? If your energy costs continue to rise, either you have the wrong mixer for the job (i.e. it wasn’t designed to deal with this particular volume or viscosity) or it requires some maintenance to bring its performance back up to the necessary levels.
• Tank Integrity – Just like the mixers, your tanks will have to endure a lot of heavy use over the years. Leaks, corrosion, and other problems can hinder your results, unbalance the mixture, and waste valuable materials.
• Oil Movement – Heat transfers, dilution, integration, and other processes require consistent and predictable oil movement. In some cases this may even require more than one mixer to ensure the petroleum products reach the necessary level of homogenization.

Mixers play an important role in the petroleum industry. Therefore, it is always important to make sure you have the right tool for the right job. Make sure that your mixer is specifically designed to handle these types of materials and keep them well-maintained to achieve a higher, more consistent ROI.

Clamp Mount Mixer (Open Drum)

These agitators can clamp to any vertical surface and are adjustable to just about any angle for mixing facilitation.  They have the greatest versatility, easily outfitted with multiple gear ratios and motor types.  Due to the fact that the clamp mount mixer is not supported by the drum directly it can also handle up to 3HP.  Mixer Direct builds two lines of clamp mount mixers, the Heavy Duty Clamp Mount line and the Economy Clamp Mount line.  Each of these can be customized to unique customer needs.  Portable and stationary lift stands are available to mount these mixers.

Drum Bracket Mixer (Open Drum)

Sometimes it is not possible to clamp onto any local surface, but you still need a powerful mixer.  The DBM line uses telescoping brackets and hand clamps to secure to steel drums and utilize larger gear systems and motors.  Axial flow turbines are standard to this unit and facilitate mixing in high viscosities.

Drum Lid Mixer (Open Drum)

This mixer is used in situations where a drum lid is required for solvent retention or splash containment.  The agitation powerhead mounts directly to the drum lid which is included with the mixer.  Different sealing packages are available for chemical compatibility.

Drum Clamp Mixer (Open Drum w/ Lid and edge bung, Closed Drum with edge bung)

Not to be confused with a clamp mount mixer, this mixer clamps onto the side of the drum and sends a shaft at an angle into the drum using the top of the drum as leverage.  Props fold to fit through the 2” bung opening and then open up in the tank by centripetal force.

Bung Mount Mixers (Open Drum w/ Lid and edge/center bung, Closed Drum with edge/center bung)

Mounting right in the 2” NPT bung, this mixer can handle both an edge and a center mount bung.  Folding impellers collapse to fit through the opening and then open up again to mix the product.

Post Mount Drum Mixers (Open Drum)

For very high viscosity or high shear dispersion of 55 Gal drums.  The mixer can be mounted on a separate post that lifts via an air cylinder to move the drums in and out of position.  This category of agitator/disperser lets one use 5 HP and above motors, large gearboxes, and high speeds.  Some industries also use this type of drum mixer for the quick processing throughput.

Please contact the Mixer Direct sales engineers if you have any questions on which one is right for you,  812-202-4047.