Benefits of Direct Drive motors - Leonardo roller mill

The roller Mill has always been one of the main machines of the cereal milling system. Thanks to Omas, all it took was a simple, yet intuitive innovation to radically change the way in which the entire milling industry works.

Omas has made all the four cylinders of our roller mill completely independent thus opening up a whole new world for the industry's professionals, reinventing the roller mill approach and optimising machine use.

Before that, the only way in which the miller could modify the machine was to calibrate and adjust the GAP, i.e., the distance, the parallel spacing between the grinding rolls. Now, the Leonardo roller mill provides the operator with different and interesting opportunities, all important and significantly helpful in ensuring more effective operations.

We are all aware that there are numerous types of cereal that each mill can process, in order to produce various types of flours, which vary and are diversified according to their organoleptic characteristics and based on the destination market.

As Omas’ Technology Manager I have had the chance to work on all continents, gaining first-hand experience of the myriad of products obtainable by milling the world's most ancient grain, and the variety of mill designs arising from the demand for the best flour, suited to the reference market.

For example, in some markets the damaged starch value is something to be achieved at all costs; in other markets, what really counts is the whiteness of flour and so there is particular attention to granulometry and the cleaning system; in other cases, the results of the alveograph, or gluten content, take priority over everything else. And the list goes on.

Laboratory end results are undoubtedly significant, but they also arise from the market needs, so it can be affirmed that within statutory limits, there is no such thing as good or bad flours, but flours that are more or less adapted to various markets and the manufacture of end products.

Another important value to consider is the by-product characteristic. Travelling and gaining experience also with by-products, allowed me to discover that some countries prefer coarse bran; others prefer fine bran. That's the beauty of the flour market.

This brief introduction on the variety of products and by-products was necessary in order to effectively illustrate the enormous advantages that the Leonardo Roller Mill can guarantees.

The main purpose of this article is to present the machine to you, through my professional experiences at different mills around the world; the second purpose is to engage a discussion with colleagues of the industry: millers from all over the world, consultants and technicians of the industry, with the aim of building constructive dialogue.?

The Leonardo roller mill is the only one in the world that can be adapted not only to the type of inbound product but also according to the desired finished product. In addition to its main adjustment features - grinder calibration and the distance between rolls (GAP), the Leonardo roller mill provides the miller with numerous other modifiable parameters, fully or partially adjustable, according to the position of the passage in the milling diagram.

Today's millers can obtain any type of requested flour to satisfy the end client in a simple way, thanks to the exclusive capacity to modify adjustment parameters, such as grinding roll peripheral speed, differential speed, i.e., the speed between the fast and slow rolls, as well as the operating position between fluted rolls. The great thing is that any change the operator wishes to make take just 5 seconds.

Upon modification of any of these important parameters, the machine in operation disconnects from the power supply, opens the grinder, waits for the new set speed to be entered by the operator and resumes operation after around 5 seconds. All data can be saved by the operator, thus creating a database and replicate previously saved recipes.

The advantages of this machine can be applied and expanded to all passages of any milling diagram, for any kind of cereal.

BREAKAGE STEPS

The first milling step is First Breakage (B1). Omas’ Roller Mill is crucial since this very first step: in few seconds (4-5”), the machine can change the peripheral speed of its grinding rolls.?Some wheats are easier to process than others and; with the easier ones the milling process easily grinds a few hundred kilos more.

Since the very first passage Leonardo makes the difference: according to the needs, the RPM of the grinding rollers can be increased and/or decreased depending on desired higher or lower plant capacity. Increasing RPM means greater and simpler product absorption by the machine.

In many mills it is necessary to change the type of wheat even 4-5 times a day, switching from soft wheat with low protein content to hard wheat with high protein content. This is an increasingly common situation due to the high demand for different products.

With particularly hard and vitreous grains the ideal operating position of fluted rolls would be DD – Dull to Dull; with particularly soft wheats, optimal milling is achieved with SS – Sharp to Sharp position.?

Thanks to Leonardo, the need to suddenly change cylinders position is no longer a problem: operating position can be changed quickly and easily changed from DD to SS in a matter of seconds. This is impossible with traditional roller mills on the market.

During B1 (fluted rolls) there is also the option of deciding whether to produce a higher percentage of semolina, or a higher percentage of flours, not only acting on the operating position, but also by modifying the milling ratio (differential).

As you already know, the standard value of these wheat processing steps is 1: 2.5.?Once more in a matter of seconds, with Leonardo it is possible to modify the milling ratio, passing from a set standard value to desired values 1: 2.0 or 1: 3.0. This enables the operator to slightly change the percentage of flours and semolina produced in that single milling step, and from the same type of wheat.

Sometimes the processing of particularly soft wheats requires a reduction in capacity, as coarse and voluminous bran causes sieving problems in certain plansifter channels. This requires the miller to reduce the total flour mill capacity and results in a loss of yield and therefore profit.

With our Leonardo roller mill this is a thing of the past, as the machine shifts from DD to SS in a blink of an eye, reducing both the percentage and size of broad bran produced in the case of soft wheat.

At this point we saw the advantages of Leonardo in the first steps of B1. Now let's try to think about what we want and we can do in the next steps (coarse and fine), when very coarse brans are required, which is the case in Egypt (DD), or vice versa, when fine bran (SS) is required, for example in Singapore.

For the miller it will be easier to control different flour parameters, such as damaged starch, water absorption, P/L values, resulting in the creation of more flours from the system of fluted rolls, or from the re-milling system. It will also be easier to decide whether to increase the P/L of flours, or the opposite, to produce more flours with the fluted roll system, to obtain flours with a longer P/L.

RE-MILLING STEPS

Let's now move on to the refining or re-milling part of the diagram: smooth rolls with standard milling ratios of 1: 1.24. On smooth rolls, modifying the differential between grinding rolls, the parameter that undergoes the most drastic change in value is damaged starch, which normally translates into increased water absorption of flour produced in this step.

With certain types of wheat and certain flours requested, the roller miller helps the operator, making it simpler for them to achieve certain results. In this case the differential speed of the machine goes from 1: 1.24 (to) 1: 1.5.

So, the increased damage starch value is mostly due to the closure and therefore the pressure exerted between both rolls, as well as the differential, which is applied between the fast and slow roll. In smooth steps, especially in top ones, we noted that increased or reduced peripheral speeds of rollers causes considerable variations in consumptions, increasing the percentage of flour produced and above all, machine noise.

Many top steps are loaded by processing hard wheats and are unloaded with other types of wheat and consequently with Leonardo, the operator can calibrate the same step in different ways, according to the produced quantity and the flour they wish to obtain from the same step.

The operator can intervene decisively on the machine, not only by acting on rolls pressure, but also according to the step and the product to be processed. They can apply different types of calibrations to obtain more or less high damaged starch values, more or less production of flours sensitive to alveograph or farinograph data. ?All this in a matter of a few seconds and with the option of saving calibration data.

In light of all this, we define our Leonardo Roller Mill a Flexy Roller Mill. It ensures extreme freedom in the processing of raw materials and a variety of end products, in a simple, fast and intuitive way.

In this article I have only considered the technical advantages of Leonardo for all millers in the world. The next article will focus on the enormous commercial advantages the machine provides compared to traditional roller mills. We'll discuss energy saving, sustainability, the cutting of plant maintenance times and expenses in new plants, mill sanitisation and hygiene and lastly, automation.

Leonardo roller mill, there is no better way to grind. ?

Sergio Tiziano Dipasquale – Technology Manager?

https://omasindustries.com/en/leonardo-omas-rollermill