What Is a Liquid Mixer?
A liquid mixer is a machine used to mix two or more liquids together. The process can be used in a wide range of industries, from textile dyeing to food processing.
Traditional mixing methods require all ingredients to traverse the vessel to repeatedly enter and exit a small, localized mixing area to achieve proper mixedness.
The agitator is an integral part of most liquid mixers. The agitator rotates immersed impellers at a controlled speed, also called revolutions per minute (RPM), which induces the flow and shear of the media inside the tank. This process causes the single or multi-component media to homogenize, allowing for a uniformly distributed product.
There are many different types of agitators, and choosing the right one for your application is crucial. You’ll want to consider factors such as the viscosity of your media, the sensitivity to shear stress, and the ability to maintain a high velocity.
Agitators can handle many different types of media, including liquids, gases, and solids. They are often used in chemical, food, pharmaceutical, and cosmetic industries.
In addition, agitators can be used to promote chemical reactions. These reactions can range from simple blending to complex chemical processes.
There are several types of agitators, but each type has its own advantages and disadvantages. The most basic type is a paddle agitator, which uses paddle-shaped blades to move ingredients from one end of the tank to the other. A modified version of the paddle agitator is a sawtooth agitator, which uses notches or saw teeth on forward puddles to move ingredients.
Anchor agitators are another common type of agitator. These agitators are designed to mix liquid mixer highly viscous and non-Newtonian fluids. They are typically mounted in tanks and vessels with conical or rounded bottoms.
Some agitators are equipped with self-lubricating shaft seals. These seals prevent foreign material from entering the product zone. They also protect the shaft from lubrication leakage and drip, ensuring that the product is protected.
For hygienic applications, agitators and their shaft seal ring assemblies must meet specific sanitary design standards. They must be smooth and have a low surface contact area that is easily accessible for cleaning.
A specialized agitator can help reduce product contamination in aseptic environments by preventing microorganisms from settling and attaching to the agitator shaft. These agitators can also prevent debris from collecting in the corners of the vessel, which may cause blockage and slow down draining.
Flow Distortion Bar
The flow distortion bar randomizes the liquid as it is introduced into the mix, allowing it to be evenly distributed and prevent agglomeration. It also adds a shear force that works in conjunction with the pin-mill system. This shear force is necessary for effective mixing of large volumes of liquids and allows for a much more efficient and faster process than traditional methods.
This type of mixer enhancement is a great example of how active mixing can be used within microfluidic devices to enhance the mixing properties of fluids, even in narrow channels. Several methods for this have been implemented, including Abolhasani et al’s use of an excimer laser to generate a ridged channel .
Adding Liquids Through The Flow Distortion Bar
The S F Fluid Zone Mixer features a unique zero-gravity fluidized zone that eliminates the gravitational forces within the chamber, ensuring that the mixture is mixed uniformly. This is the key to a successful liquid mixer.
However, some of the larger volumes of liquid that may need to be added to the mix can cause issues with mixing efficiency. This is why the S F Fluid Zone Mixer includes a special liquid-addition feature called the flow distortion bar and pin-mill system.
These are counter-rotating and stationary milling rods that work together with the fluidized zero-gravity zone to create additional shear forces that agitate the surface of the mix as it exits this zone, ensuring that the liquid elements are evenly distributed. The flow distortion bar and pin-mill system are designed to increase the efficiency of liquid addition to a wide range of mixer sizes.
Using The Flow Distortion Bar
This mixing enhancement is especially effective for liquids that need to be introduced quickly and efficiently into the mix, such as absorption or coating agents. It also improves the speed of addition when using spray nozzles.
The S F Fluid Zone Mixer also features a flexible filling level from 40% to 140%, so that the same perfect mixing results can be achieved independent of bulk density and material properties. This makes it the ideal choice for large batch processing.
Flow Distortion Shaft
Flow distortion shafts are used to enhance the mixing capability of liquid mixers. They are also useful for introducing liquids to a mix in an efficient manner. The most commonly used type of flow distortion shaft is the radial flow impeller.
The radial flow impeller produces a high degree of shear, so it is ideal for mixing viscous media and gas-liquid dispersions. These impellers are often used to mix liquids within elongated tanks.
A tangential flow impeller causes the fluid to rotate around the shaft, producing low shear and less flow than radial flow impellers. These impellers are also used for blending highly viscous media and stratification.
Another type of patterned structure used to improve mixing is the herringbone mixer, which is similar to a slanted well in that it provides a smooth, non-uniform surface. This structure can be fabricated easily and offers a high level of mixing capability.
Recently, Xia et al demonstrated a method of creating a herringbone-like pattern through the undercutting of a glass plate by chemical etching. This ridge-like formation mimics the slanted well structure and can be fabricated in a single step.
This technique can be adapted to microfluidic devices and is an effective way to increase the effectiveness of a mixer. It is also easy to implement in existing microfluidic systems, so it can be used for a variety of applications.
Glasgow and Aubry observed that pulsation of both fluid streams in a simple mixing channel increases the degree of mixing to a significant extent. They found that a liquid mixer 90deg phase difference between the pulsation of each stream provided the best mixing results.
Using this technique, Glasgow and Aubry were able to achieve 5 times greater mixing than simply pulsing one of the streams alone. This can be beneficial in a number of different applications, such as enhancing the mixing capacity of liquid droplets , or even allowing multiple reagents to mix together.
The flow distortion shaft can be incorporated into any type of liquid mixer, as long as the system is designed properly. Adding this device can help improve the mixing capabilities of the mixer, especially when dealing with large volumes.
Flow Distortion Plate
A liquid mixer is a fluid mixing device designed to mix a large volume of liquid. A typical mixer will include an agitator, a shaft, and a flow distortion plate (or plates).
There are several different types of flow distortion plates available for use in liquid mixers. Each of these has its own unique features that make it useful for specific applications.
The first type of flow distortion plate is a patterned ridge structure. These ridges were created as a result of undercutting during the chemical etching process. The resulting flow patterns are similar to the ones seen when using a slanted well or herringbone structures.
Many researchers have investigated the use of these patterned ridges to enhance mixing within microfluidic devices. They have all found that a patterned ridge structure can greatly improve the effectiveness of a fluid mixing device by adding additional turbulence and creating chaotic mixing within the system.
Some of these ridges are even affixed to the walls of the channel, increasing their effectiveness. This technique also eliminates the need for an agitator, shaft, or other device that would otherwise be required for this type of mixing enhancement.
Another method of enhancing the performance of a liquid mixing device is to create wavy interfaces between the streams. Tsai and Lin used a thermal bubble actuated nozzle-diffuser micropump to generate these interfaces, which can be observed in figure 9 . Once the bubbles are pumped into the system, they oscillate, inducing mixing effects.
In addition to enhancing mixing, these wavy interfaces can decouple the channels from conductive heat transfer. This allows for increased cooling of the device, which increases the life of the device and decreases maintenance costs.
This type of mixing enhancement can be used to mix fluids in a wide range of geometries, and is particularly helpful for applications where a single channel is not sufficient. It can be especially useful when the two fluids being mixed have a high liquid content and low vapor pressure, since it can reduce recirculation of the fluid within the channel and increase its mixing efficiency.