Ribbon Blenders and Dry Blender for Process Applications

Another alternative is to rely on a variable frequency drive (VFD) to start the blender at slow speeds. New generation VFD's are capable of safely soft starting ribbon blenders even with high-density applications. They also provide convenient speed control anytime during the blending and discharging cycles unlike electronic soft starters that allow slow speed only when starting. The functionalities for soft start, overload protection, adjustable starting torques and speed control make VFD's the best performing and cost-effective option.

For more Ribbon Mixing Machineinformation, please contact us. We will provide professional answers.

Electronic starting systems offer a more practical choice. Electronic soft start controllers can be programmed to allow a slow start under full load and protect the system against a spike in start-up torque in the drive train. Experience tells us that they are more reliable, require less ongoing maintenance, and cause less downtime.

For every minute that your blender is committed to discharging and cleaning, production is sagging. So, efficient discharge has become another important focus in ribbon blender design. Fast discharge is a function of axial pumping action - especially the pumping action of the outer ribbon - and the discharge valve design. Complete discharge requires close clearances and a clean design in the interior trough.

Naturally, the ribbon is specified to provide sufficient surface area and peripheral speed to move the bulk. An equally important measure is the differential between the inner and outer ribbons in the double spiral ribbon set. This differential determines the axial pumping action that ultimately moves the material toward the discharge. The challenge is to induce vigorous agitation without over-stressing the ribbon, rods and shaft. For this reason, the system should be designed from the ribbons inward. Ribbon design determines the rod design, which in turn determines the shaft that is needed. A balanced design provides a system that blends quickly, produces minimal resistance as the ribbon/rod assembly moves through the bulk, and ensures long-term reliability. Oversized support rods, for example, often cause cracked ribbons and unnecessarily high power consumption.

Especially when blending abrasive materials, and when contamination is a critical concern, air-purged seals help to prevent material from attacking the packing material and shaft. (Nitrogen is used when blending materials that are prone to oxidation.) In industries that require sanitary blending, TeflonÒ v-rings are commonly used to provide a seal that is reliable and easy to clean quickly. In many pharmaceutical applications, for example, the split packing is easily opened and cleaned after every batch.

The valve most often specified for a ribbon blender is a pneumatically-actuated sliding gate valve. But for special applications - vacuum operation, for example - alternative valves are sometimes required. A spherical disk valve provides a positive seal during vacuum blending, while it also offers a large discharge port for fast discharge.

After choosing the desired features you should contact the manufacturer and run a test on your product, in the manufacturers Test Center or in your own factory. Nothing beats the satisfaction of knowing that you have chosen the best possible design for your requirements.

How does a Vertical Cone Screw Mixer compare?

Ribbon blenders and vertical cone screw blenders are found in many plants, and in many ways they perform a similar function on the process line. But the differences in their design - and in the advantages they offer - are far more important than their similarities.

Of course, one very important difference to consider is price. The ribbon blender is generally less expensive than a vertical cone screw blender of comparable capacity. So, in practical terms, you should determine whether you application requires a vertical cone screw blender in order to achieve the product quality and processing efficiency that you need.

To decide which type of blender will work more efficiently in your application, ask yourself these questions.

1. How much room is available on your plant floor? Before we even start talking about your blending needs, you can answer the first important question with a tape measure. If floor space is tight, you may have to go up - with a vertical blender - since a vertical blender requires a much smaller footprint. If overhead space is limited, you may be forced to use a horizontal ribbon blender, which allows you to use a low-profile loading system. A multi-level operation is generally unnecessary.
2. Does the friability of your product require gentle blending? If so, you will probably need a vertical cone screw blender. The blending action of mixing screw is extremely gentle.
3. Is complete discharge essential? The cone screw blender gives you virtually 100% discharge through the lower cone. Even the best ribbon blenders fall short.
4. How tight is your budget for power? Since the cone screw blender consumer 25-30% more power, over long blending cycles this can add up.
5. Is contamination a critical risk? With a packing gland in the product zone, the ribbon blender always poses a great threat of contamination. New seal designs have reduced the risk dramatically, but if your application requires the best protection available, you will have to switch to a cone screw blender.
6. Is your product heat sensitive? The blending action of a ribbon generates more heat than that of a mixing screw. In the cone screw blender, heat is also more easily removed with thermal jacketing.
7. Will you always operate with the blender at least half full? If you need the flexibility to operate with smaller batches, choose the cone screw blender. Because of the geometry of the cone, this blender can operate efficiently with batches as small as 10% of blender capacity. The ribbon blender generally requires a minimum of 40-50% capacity.
8. How fast do you want to finish the batch? A fast blending cycle is not always the most important concern, but it is always a factor you should consider carefully. Cone screw blenders are usually about 30% faster than ribbon blenders in similar applications.
9. Are you concerned about blending accuracy? The ribbon blender and cone screw blender both produce a well-blended product. But the cone screw blender will virtually always produce a more homogenous blend in given blending cycle. The difference is not critical in all industries, but if you want to get as close as possible to perfection, you will probably need a cone screw blender. If accuracy is critical, be sure to test the blender in your manufacturer&#;s laboratory before you buy it &#; to prove that it can deliver the product quality you need.
10. Will you need complete cleaning between batches? The cone screw blender is easier to clean, especially since you will never have to disassemble a packing gland in the product zone. Just make sure that the cone screw blender you select does not require a bearing at the lower end of the screw. A screw supported entirely from the top end will give you faster, more thorough discharge, easier cleaning, and fewer maintenance headaches.

Blender Selection: A Case In Point

At a major Urethane manufacturer, a international leader in the production of thermoplastic polyurethane film, blending is a crucial process step before resin, colorants and lubricants can be fed into an extruder. Consistency and throughput are critical, since demand for polyurethane film is soaring. A hot product in the plastics industry, polyurethane film is fast replacing polyethylene and polypropylene film in manufacturing such products as greenhouse glazing, rain coats and sporting gear, seals and gaskets, and fuel cell linings.

Following a recent plant expansion, the company now runs ten process lines - including the only line in the world that produces 120&#; ultra-wide film. A ribbon blender on each line feeds a high speed extruder, and together they produce hundreds of unique formulations for customers worldwide.

Are you interested in learning more about Double Cone Mixing Machine? Contact us today to secure an expert consultation!

They change products constantly, so they have to clean each blender three or four times a day. This company switched to a ribbon blender design that allowed fast discharge and easy cleaning.

To select a ribbon blender, you have to look closely at the small details in design and construction. With a short blending cycle and a product that is not particularly shear-sensitive and does not require vacuum, there was no need to consider a switch to a cone screw blender. But floor space in the plant was still an important consideration.

This client was concerned about the space that would be required by the horizontal blenders. But they found that the Ross ribbon blender is actually more compact that the blenders they were replacing. A right-angle gear drive gives it a small footprint. And since the drive is not a separate stand alone unit, it is easy to move and maintain.