CONICAL SCREW MIXER (NAUTA MIXER)(also named Nauta Mixer, cone screw mixer, vertical screw mixer) consists of two screws located at the vessel wall product the bottom of the conical vessel to the top. The screw is attached to an arm, which rotates around the vessel’s perimeter, causing convective mixing and shear. The particles at the surface opposite the screw accelerate downward in a mass flow by gravity as the vessel’s diameter decreases. The three actions result in a unique three-dimensional mixing action.
These versatile batch mixers are unique in many ways. Their design provides for a very gentle mixing action with low horsepower consumption.
The conical vessel design allows a wide range of filling capacities. The mass flow characteristic design minimizes segregation upon discharge. Because there are no horizontal internal surfaces, products are completely discharged, minimizing product loss and providing easy cleaning. Vessels can be designed for overpressure and under pressure operating conditions. We supply Units with various accessories, including liquid injection, product samplers, high-intensity lump breakers, level, temperature probes, and load cells for batch weighing, and jackets for heating and cooling are some examples.
The Conical Screw Mixer is a batch type mixer explicitly designed for low-intensity mixing of easily segregate materials. The Conical Screw mixer is also used for materials such as powders and pastes. It is ideal for use in relatively delicate materials or end-product properties and processes that require highly accurate results. Typically, the Conical Screw Mixer is famous for the fine and intricate mixing of large volumes of materials. The Nauta conical screw mixer is famous for its low-intensity mixing and is a pioneer in mixing technology. It’s especially suited for delicate products and processes where very accurate results are required and are synonymous with gentle mixing of large volumes of up to 100,000 liters.
The Nauta conical screw mixer is a convective mixer with high mixing efficiency. It is gentle and guarantees the highest level of mixing accuracy without product distortion. The screw has an average speed of 70 rpm while the arm rotates at 1 to 2 pm. The tip speed of the screw can fluctuate between 0.5 and 2 m/s, making it suitable for all ATEX zones. The rotating cantilevered (free hanging) mixing screw conveys the product from the vessel’s bottom to the product surface. The mixing screw is suspended from an orbital arm, which rotates the mixing screw along the conical inner vessel wall causing convective mixing of particles and shear. When recirculated by gravity in a conical vessel, particles’ speed in the downward mass flow increases as the vessel diameter decreases. These simultaneous actions result in a fast and intensive mixing with low consumption of power and high mixing accuracy standards.
Wide variety of processes
Nauta mixers are suitable for a wide range of processing activities in the pharmaceuticals, food, plastics, metals & minerals, nuclear, chemical, pigments, and coatings industries. These include:
- · Gentle mixing of free-flowing and segregative powders, pastes, slurries, and liquids
- · Moistening of powders
- · Coating
- · Granulation
- · Drying using heat input at atmospheric conditions or in combination with vacuum and possible liquid recovery
- · Coating of solids with liquids (with intensifier)
- The first step is charging of mixer from the top, manually or vide pneumatic or mechanical conveying. After the mixer is charged, the mixing process starts. The mixing is carried using 3 distinct intermixing actions:
· The screw agitator, turning on its axis, produces a lifting action as it spirals the materials in an upward flow.
· At the same time, orbiting the tank, the screw removes material away from the wall and deflects it into the center of the tank.
· Material lifted by the screw gravitates downward, thoroughly intermixing with the material being spiraled upwards.
The typical speed of the central screw is 70 to 80 Rpm. The Tip speed can fluctuate from 1 to 3 m/s. The result is a most intimate intermingling of all ingredients. The mixing time is depending on product characteristics, mixing accuracy, and batch size.
Vertical ribbon blenders are generally used in applications requiring gentle mixing action and minimal heat generation. At the same time, these mixers can also be used for applications that require high shear mixing. This is accomplished using lump breakers, which are driven separately.
- Mixing of free-flowing powders
- Moistening of powders
- Drying of powders
- Mixing of slurries