The Component Of Ribbon Mixer&How to choose a ribbon mixer

The Component Of Ribbon Mixer
Here we will introduce the important component of ribbon mixer, and how does work? We refer an active mixer as one in which there are either internal moving parts to randomize the positions of the ingredients, or air jets to create convection currents and turbulence in the powder container.
The first step of the industrial mixer that we will consider is the ribbon mixer.
In a ribbon mixer, a long complicated single paddle is mounted axially and used to disperse the ingredients of the mixture. The ribbon is usually so constructed that the powder near the outside of the container is moved in one direction, whereas in the middle it is moved in the opposite direction. Ribbon mixer are available from several manufacturers and they all have their own type of ribbon. The reader should note that many of the companies mentioned with respect to a particluar type of mixer in the discussion often make other type of mixers, as set out in their catalogs.
Ribbon mixers are widely used in the food industry and the pharmaceutical industry. This type of mixer can have dead pockets, especially near the end of the mixer close to the axis of rotation. Loading and cleaning of a ribbon mixer is asually done from the top of the mixture. The manufacturers usually recommend emptying the system at the end of the mixer. Van den bergh points out that attention must be paid to the design of the mixer, bearings and glands to avoid lubrication contamination. He also states that ribbon mixers are not easy to clean and not recommended for sticky materials. Because the mixing device turns over the whole charge of powder, the powder demands of this type of mixer are relatively high, thus van den Bergh gives an estimate of 12 KW per 1000 kg of charge.(Many of figures on powder demands and of available capacity in industrial mixer are taken from an excellent review article by van den Bergh).
One does not normally fill this type of mixer to more than 50% of the available volume. Normally the capacity of this type of mixer is restricted to anupper limit of 15 m.
Sometimes, to improve the dispersion of ingredients in ribbon mixers, the ribbon blades are built to be close to the cylindrical wall to give high shearing. Sometimes the ribbons are also fitted with rubber wipers to ensure complete intermingling of the ingredients by lifting any packed material near the wall into the middle of the ribbon ensemble. It is difficult to predict the scale-up performance if one attempts to increase mixing captcity by going to a larger mixer of the same type.
In a ribbon mixer the paddles move relatively slowly, as distinct from the movement in another class of mixer which is variously referred to as a paddle or a plowshare mixer.
How to choose a ribbon mixer
1. According to the daily output of the selection of ribbon mixer. Mixer as a result of the processing time for each batch of material about 6 minutes, add the feed materials and discharging time, each batch of materials processing time can be 10 minutes total, 1 hour processing can be expected to grant 6.Users can choose ribbon mixer according to their need

2. According to the ribbon mixer with the working principle for stirring mixed with the double helix in the opposite direction to push the material's ability to be in the same. As the spiral with the pitch should be less than the outer spiral bands to push the material's ability to achieve consistent, with the spiral pitch should be less than the outer spiral band, and should be greater than the width of the belt outside the spiral, or materials to make a direction Focus.

3. According to the principles of design, with screw-in mixer with spiral shell with space for between 4 mm to 10 mm, friction materials can lead to participate in all mixed. However, due to crush size and material of different coefficient of friction, it will participate in the various components of the mixed materials are not the same time, resulting in non-uniformity of the product. At present, some manufacturers have been aware of this and improved products. One is the attention to the processing precision, so that by the end of reducing the gap to 1 to 2 mm; the other is the axis between the shell and into position in the form of adjustable, according to the amount of wear and tear can always adjust screw with the gap between the shell. In the choice of mixer, both in the form of the product should be the best choice.

4. Choosing Ribbon mixer Should Pay attention to discharge method. Should choose to open the door in the form of large, do not choose the side or bottom of the small openings in the form of material. The reason is: when the mixer required to complete mixing mixed after a put-money in the shortest possible time to ensure uniformity of materials; such as the mouth or the side of the small openings at the bottom of the spiral with a net release gradually, first, delay time, less than expected Productivity, and the other is this material has reached the best uniformity, over-mixing it will disintegrate materials, the destruction of uniformity, which lost its choice of ribbon mixer.A typical design of a ribbon mixer
Horizontal trough mixers consist of a semi-cylindrical horizontal vessel in which one or more rotating devices are located. For simple operations, single or twin screw conveyors are appropriate and one passage through such a system may be good enough. For more demanding duties, a ribbon mixer, like the one shown in fig.1.may be used. A typical design of a ribbon mixer will consist of two counteracting helical blades (called ribbons or spirals) mounted on the same shaft. Ribbons convey materials inside and outside in opposite directions forcing them to intermix, the mixing tool and vessel are typically made of stainless steel. One moves the solids slowly in one direction. While the other moves it quickly in the opposite direction. There is a resultant movement of solids in one direction, so the equipment can be used as a continuous mixer. Some other types of ribbon mixers operate on a batch basis. the mixer can have more than one discharge so different batches can be discharged to different processing lines .in these designs .troughs may be closed to minimize dust hazard ,or may be jacketed to allow temperature control. Due to small clearance between the ribbon and the trough wall. this kind of mixer can cause particle damage and may consume high amounts of power.
Another possibility is that the ribbon mixer is in its vertical position. These mixers operate at relatively low speed to gently handle materials while providing enough intensity to thoroughly blend them in a relatively short time cycle (typically1/3 to 1/2 the time of conventional horizontal ribbon mixers).the mixer has a filling capacity of up to 90% of the gross volume of the mixer.

ribbon mixer for industrial.
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The Component Of Ribbon Mixer&How to choose a ribbon mixer