Milling process project optimisation through strategic design

17 February 202010 min reading

The new approach to process design is the interaction amongst all systems, their interface and the streamline of functions and processes that take place from A to Z. By new design, an industrial process may need less equipment, or better graded and selected equipment, consume less energy, be more efficient and work in a straight operational line fully integrated…Three objectives paramount to the food industry today: economic results, quality of product, environment and working conditions.

Alex Bignoli Seward Alex Bignoli Seward Project and Business Designer COGEA Ltd-Rome

More than ever before applied design has played a fundamental role in the “thinking” of a new process line, a new facility, a sea, rail or land transport terminal…and more than ever applied to a complete interface and inter functionality of all systems. Likewise, analysis of existing facilities under design reprocess may show a cost-cutting margin of relevant importance when adequately implemented.

This study enhances the main aspects of this subject by considering the advantages of a correctly thought of the project, by planning in advance the whole integrated systems that will complete the production steps, and by re’thinking’ the existing process facilities.

Design by itself, no longer applicable… History tells us something

Seeing high-quality process facilities, magnificent milling machinery, high quality conveying systems, best of class hoppers, silos, mills, plansifters and the whole range of process components is certainly a pleasure for the eye, but not always a pleasure for the mind, as in many cases, and more often than not, these systems are not adequately interfaced or not adequately designed from input of raw material to output of finished product.

durum wheat

Industry has learned from the past: individual systems cannot have a successful output if not interfaced and coordinated with the rest of the process line, and even the best-coordinated system will face productivity shortsteps if not designed together with the previous step, i.e. the port terminal that will feed the grain to the mill for example…

At the other end, even with all coordinated lines, the system will again find a pace stopping situation if there is no sufficient space for the storing of finished products or for the adequate capacity and speed of re delivering to the market.

Design today looks at the actual drawing of systems that will be strategically thought of in speeds, capacities, volumes and all other parameters to the needs of the line, from A to Z. In other words, mathematics first, algorithms applied then, and design to follow by value engineering.

Process lines are never alone! Neither process design!

A correctly calculated input of raw material will ensure the needed feed into the production line, but this is not enough. Production lines may need unexpected stops, feeding conveying lines may also have occasional breakdowns and maintenance, inbound vessels, trains or trucks may have delays, and even all going well the grist may need to be changed or altered due to quality requirements to be fine-tuned…

In the same way, the feeding of the final product to the bagging lines and from these to the delivery point or loading bay may have its own time schedule and time programming of deliveries on to the receiver of the goods.

It is here where the strategic design comes in, programming and planning together with the end-user, the industrial facility, the correct speeds, capacities, quantities and volumes to be fed, stored, the buffer volumes, the adequate spaces to be designed and the delivery program together with the input of raw material program.

durum wheat


The first question to be asked is “where does it all start?” The answer would be to define the final product that will be consumed or fed to the market but it is more ahead than what the designer will need to look into. The first question in a more elaborated project manner will be “where from, how and when and in what quantities my industrial process needs the input of wheat or raw material?” The first parameter a project designer will have to look at is the input of raw material, and where they originate, how they arrive and how they are handled previously to be fed into the production line.

From the industrial revolution onwards the progress made would be difficult to quantify, but the last 20 years have seen more applied design development than ever, not as much related to new machinery or new processes, but the design thinking approach to industrial processes and their interface and intercoordinated pace.

What has changed? The new approach to process design is the interaction amongst all systems, their interface and the streamline of functions and processes that take place from A to Z.

By new design, an industrial process may need less equipment, or better graded and selected equipment, consume less energy, be more efficient and work in a straight operational line fully integrated.

The algorithm to follow the path of the goods from raw material to final product evaluates every single step of the ongoing path, studying and analyzing each step in itself and designing the next one and the one after considering quantities, capacities volumes speeds and all other to be perfectly coordinated in the most efficient chain of process.

durum wheat


Where does industrial planning start? Certainly with the buying ahead of the raw materials needed to produce our product, meaning with our commercial position, as it may be either long or short, most clearly if we are a flour mill and we produce an X amount of flour per year and we have not covered our needs in advance, our industry is “short” of the equivalent raw material to produce, i.e. We are at risk that prices may go higher and we may have to pay more for the wheat needed, or go down and hence we will sell our flour at a lower price…This is the first step of process design…The supply chain program, the shipping program that will satisfy the needs of our industry…

Following the shipping program, it will need to be defined the sizes and types of vessels to receive and to establish the break-even point between lower freight rates in larger vessels or financial costs to pay for smaller vessels to be received in more smaller shipments than one big shipment for various weeks or months…to be our financial planning program…and from this to the receiving, berthing, unloading, conveying, storing, conditioning and finally into the milling process…but all of these will have to be consciously designed well before and well defined in order to have the highest possible efficiency to then proceed to the next step.

Once the buying in of raw materials is completed, the logistics and the physical transport of goods will start to supply the industrial facility, and it is at this point that functional efficiency comes in.

Discharge: Applied design will calculate the amount of goods that will be received in each shipment, its volume, specific weight and from there the best way to discharge them, delicate goods as rice or durum wheat will be handled better by grab rather than with a CSU, and even less with pneumatic systems that will increase the breakage of the grains, other products may have less vulnerability and will be better discharged with a CSU system or with pneumatic equipment. Having this in mind the designer will calculate the correct power and capacity of the discharging equipment and then the receiving hoppers and conveyors belts to transport the goods to the initial storage.

Initial receiving storage: The calculation to follow is the conditioning of the goods and the capacity of the initial storage that may be coordinated with the conditioning equipment to clean the wheat from impurities, stones, other cereals, and inert material to send it, once cleaned, to the medium and long term storage.

Speeds: The calculation of coordinated speeds between the discharging equipment, the conveying equipment, the receiving pit, elevators and cleaning, and conditioning systems will play an important role, as all of them will work in an orchestra combination to discharge the vessel without delays, and to deliver the goods to the process line in the best possible condition and without interruption of the feeding lines.

Process: A special eye that designers will dedicate to this step together with the engineering of the process lines is to match speeds, capacities, volumes and output with the required quality, meaning better to mill less wheat per day obtaining a better quality of flour and not increasing the flux of process but creating a post problem of quality control and intrinsic quality itself.


Calculation of the buffer capacity to feed the bagging and packaging lines, calculation of the spaces needed to store the pre-delivery finished products, calculations of how to load and the volumes and speeds needed to load on a day to day basis will give the line the necessary parameters to be respected in order to:

• Maintain the production lines in running rhythm without stoppages, • Keep the goods stored for a short period of time before delivery • Have enough space to store and deliver without short quantities mishaps • Keep the bagging and packaging plants fed without interruption


A path to be followed to enhance efficiency, cost minimization and process functionality, a path that designers and engineers will keep building up to obtain value engineering, applicable to both the actual production units operative, and ideally when projecting and planning new facilities.

Designers will feed the engineers database with the knowledge of speeds, capacities, yields, volumes, and coordinated process lines in order to enable them to project and program the needed equipment to be installed and the spaces needed for the civil buildings, not only for the production lines but also for the accessory services, that are a sine qua non-condition to have an industry running, Administration blocks, services areas, parking availability, analysis, and laboratory spaces, maintenance workshops, amenities sectors and all related to human labor well being, that will make efficiency still higher and functionality optimized.


The analysis and redesign of existing facilities has proven that up to a 35% of direct and indirect costs have been saved in various process plants by bringing in specialized designers to “study” and “analyze” the actual situation and ask themselves how to improve the distances from storage to process, the speeds of discharging and storing, the distance from process to bagging, the speeds and capacities of each step of process coordinated with other process steps, the isolation of the Administration block and analysis laboratories to avoid vibration and noise from process lines, the rescaling of all conveying paths, elevation systems and land transport of final goods…In other words to re“think” the whole line on a more competitive, efficient and functional coordinated order that will save costs, time and surely improve working conditions.

On new facilities, the first thing to do nowadays is the feasibility study of the project, with a strong vision of the strategy of process coordination behind it, designers and engineers will layout the final project only after the strategic calculation described above has been done and tested mathematically till there are no mishaps found.

In both cases, may it be a new facility or the refurbishing of an existing facility, the strategic design, and engineering applied by commonly shared information of process and the full chain from supply to final delivery of final product, will play a significant role both in the economic result, as well as in the quality of product and working conditions of the industry.

Three objectives paramount to the food industry today, economic results, quality of product, environment and working conditions.

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