Improving Accuracy in Automated Processing Systems: Improving Process Design

Improving Accuracy in Automated Processing Systems

For automated processing to work in any industry, from food processing to chemical processing to pharmaceuticals and more, ingredients must be weighed accurately. In our previous post, we explained how to choose a load cell and scale instrument that works best for your mix. In this post, we’ll cover other factors that influence the accuracy in an automated processing system, including the feeder, system controls, scale mounting position, and surrounding environment.

Improving Accuracy in Automatic Weighing: Improving Process Design and Eliminating Interference

Type of Feeder

For the weighing system to work properly, the feeder and the scale must be coordinated. A larger feeder delivers more material at a faster rate, which can decrease the total time the process takes. However, if the feeder is too large, it can throw off the accuracy of the system.

The feeder, like the scale, must be suitable for the smallest ingredients and the largest. Consider how much material passes through the scale per second, and how long it takes to stop the feeder. If, for example, the feeder can deliver 1 lb of material in one second and it takes at least one second to stop, the smallest amount you can feed will be 1 lb. If your scale is accurate to within .01 lbs, this level of accuracy won’t be useful as long as the feeder is too large.

It is possible to program your system to account for this delay by stopping the system one second earlier. But, remember that there may be some variation in the time it takes for the feeder to stop. This is mostly impacted by the controls orchestrating and coordinated the system.

Type of Controls

Adding more machines and automating more tasks can improve accuracy in an automated processing system, but not if the control system is overloaded. If your controls don’t have enough power to efficiently execute each task in turn, they’ll start building up, and each one will be delayed. As you upgrade and expand your system, be sure to check in with your controls as well. If this part of your system can’t keep up, pinpoint precision elsewhere won’t matter.

Scale Mounting

To get an accurate reading, the scale must be free-standing. If rigid attachments bend or lean against the scale, they can hold it up and throw off the reading. If other objects such as power cables or pneumatic lines rest on the scale, this will also create inaccuracies. Be careful not to place other machinery and objects too close to the scale. While effective space utilization can increase plant efficiency, this shouldn’t come at the expense of the equipment’s operation. Some equipment may need to be moved, or the system reconfigured slightly, to give the scale enough room to operate properly.

Manufacturing Environment

The environment surrounding the scale also plays a role in the functionality and accuracy in an automated processing system. A number of environmental conditions can affect the functionality of the scale, including:

  • Vibration
  • Air currents
  • Temperature
  • Electromagnetic interference

Interference due to vibration is one of the most commonly overlooked causes of scale inaccuracies. The vibration may be constant, such as vibration caused by nearby machines or processes, or it may be sporadic, such as vibration caused by a passing vehicle. You’ll be able to detect interference through vibration by running a test and watching the scale. If the scale reading fluctuates by a degree higher than the scale’s target accuracy, you may need to rearrange processes, absorb the vibration with shrouding or mounting, or filter it electronically.

Proper testing from the outset can help you detect other environmental issues that can affect your scale. Sometimes though, conditions around the scale may change. If the recipe shows multiple inaccuracies, examine the area around the scale. If new machines or ventilation equipment were added or processes reconfigured, they may have disrupted the scale. Temperature changes such as those occurring during summer peaks, can also throw off the scale.

Improving Accuracy in Automated Processing Systems: Finding the Right Load Cell

improving automated process accuracy

Automated systems have made food, pharmaceutical and chemical processing systems faster and more efficient. An important part of this process is the accurate weighing of ingredients. As ingredients have become more concentrated, the importance for highly accurate scales has increased. The challenge for many engineers is designing an automated system that is both efficient and accurate. To improve weighing accuracy in automated processing systems, you have to start with the load cell. Finding the right load cell can help to improve the accuracy of the automated process in general, without sacrificing efficiency.

Improving Accuracy in Automated Processing Systems: Load Cell Capacity and Weighing Instrument

The load cell capacity, weighing instrument and the ingredients themselves all play an important role in the weighing accuracy of automated processing systems, regardless of the industry they’re used in. In today’s blog post, we’ll start with these important factors. Other considerations, like the size of the feeder, the scale vessel mounting position, the controls, and environment, also play an important role, and we’ll cover these in our next post.

Load Cell Capacity vs Scale Instrument Capacity

Finding the right load cell means looking at both the weighing sensor and the weighing instrument. How a scale displays weight and the most accurate measurement it can use are determined by the weighing sensor, commonly called the load cell, and the weighing instrument, commonly called the scale head. A typical load cell is accurate with 5,000 divisions. So, in a 100 lb cell, it could display incremental changes by .02 lbs.

More finely-tuned scale instruments make it possible to improve this accuracy further. Most scale instruments can exceed load cell capability, with the ability to divide by 10,000 or even 20,000. So the 100 lb load cell could show increments of .01 lbs or .005 lbs, respectively.

Scales legal for trade must adhere to scale standardization rules published in the National Type Evaluation Program’s Handbook 44, and scale instruments with this level of specificity are considered outside the standard. However, process scales may not be required to meet these standards, and the additional accuracy offered by the improved scale instruments can improve accuracy in the automated process.

Full-Scale Capacity vs. Individual Ingredient Accuracy

The scale’s division accuracy is a percentage of the full-scale capacity, sometimes expressed as the full scale capacity multiplied by the division. For example a 100lb scale may be shown as 100lb x .02 if the scale divisions is 5,000. This is often misconstrued with an individual ingredient’s accuracy requirement. If, for example, the scale is accurate to within .02lb and an ingredient requires 2% accuracy, it’s easy to assume that the scale will be sufficient. However, this is not the case. It depends on how much you are trying to weigh.

For example, 1% accuracy in a 100 lb scale is 1lbs. If you are trying to weigh 25 lbs of an ingredient on the 100 lb scale with a scale division of .02lb to within 1% then you will be OK since the .02 lb division is 8 hundredths of a percent of 25lbs. However, if you want to weigh .25 lbs of an ingredient in the same scale and you are off by one division of the scale then the potential error is 8% of the target weight. In order to find out what the minimum division should be for .25 lb target weight with a desired accuracy of 1% we need to divide .25 by 100 to get the desired percentage of the target weight. This means that the scale divisions would have to be .0025 instead of .02 so the scale should be much smaller.

Efficiency vs. Accuracy in Automated Process Weighing

The use of small amounts of highly concentrated ingredients alongside larger amounts of base ingredients presents a measurement challenge. A scale that is large enough to measure out the larger ingredients may not be accurate enough for the smallest ones, but a scale that’s accurate enough for the smallest ones will be too small for the large ones.

There are a few solutions to find a balance between efficiency and accuracy in automated process weighing:

  • Use two or more scales. Divide the recipe based on the desired accuracy for each ingredient. Two 50 lb scales capable of 5,000 divisions will each provide .01lb divisions, which will be twice as accurate as one 100 lb scale capable of 5,000 divisions, and the two scales working simultaneously will maintain speed and efficiency.
  • Fill a smaller scale more then once. If there is an ingredient that exceeds the scale capacity then it is possible to weigh the ingredient up to the scale’s capacity, discharge the scale and continue to weigh the same ingredient in the scale until the target weight is achieved.
  • Use a microingredient system. A specialized microingredient system can increase efficiency when there is a significant difference between the amounts and accuracy between highly concentrated ingredients and base ingredients.
  • Dilute the ingredient. A highly concentrated ingredient may require accuracy within +/- .01 lbs. However, if the ingredient is diluted—say, by ten times—the accuracy will drop to +/- .1 lbs.

Finding the right load cell and scale to accommodate every ingredient in the mix is the first step towards creating an automated processing system that is both accurate and efficient. In our next post, we’ll cover the next elements to consider, including the feeder, controls, surrounding environment, and more.

The Best Automation Upgrades for Feed and Pet Food Processors in 2019

Improving efficiency in 2019 is a top priority for many feed mill and pet food processors. Automating processes or upgrading existing automation is often the way to maximize efficiency gains, but it can be difficult to know where to start. We’ve made a list of the best automation upgrades for feed and pet food processors to help you prioritize your improvements.

7 Automation Upgrades for Feed and Pet Food Processors in 2019

1. Process Time Optimization

The most efficient feed or pet food process automation aligns all process times, including filling, weighing, discharging and mixing, for all ingredients. While exact timing is difficult given high-speed and low-speed estimates, and other variance, machines should not be sitting idle for long periods. There are many ways that you can improve the process time of the bottleneck machine in order to meet the timing of the upstream or downstream processes.

If your mixer is idle, consider dividing ingredients into two or more weighing and filling stations, using a different faster weighing mechanism, or using a larger feeder for faster filling. If your scales or hoppers are idle, optimize your ribbon mixer by; dividing mixing between two or more mixers, using a larger mixer, using a drop-gate for immediate discharge, or using a larger motor to speed up mixing.  

Get the secrets to feed mill and pet food automation systems design. Download the Engineer’s Guide to Weighing and Batching >

2. Scale System Improvements     

It is possible, with the right scale and weighing strategy, to speed up this process without sacrificing accuracy. A variety of different weighing systems exist, with versatile features to suit your facility and your ingredients. With a mass-flow continuous weighing system, you can measure your ingredients accurately without actually creating any pause in the system. By using roll-over tubs, slide gates or butterfly valves, you can eliminate delays in the discharge phase. If you’re using conveyors due to facility height restrictions, you can weigh and measure materials while moving them. If your scale system is holding up the rest of your process, consider this feed and pet food processing automation improvement first.

3. Ribbon Mixer

If you haven’t looked at your mixer in several years, this can be a viable upgrade to improve plant efficiency. With low shear, fast mixing times, and a streamlined design, ribbon mixers eliminate many mixing problems, like dead zones and overmixing, that other mixers create. When you upgrade with a ribbon mixer, you can reduce mixing times and improve total output, but this may require altering downstream processes to match the new mixing time. A ribbon mixer can also reduce maintenance costs and downtime.

4. Mistcoater

Appling uniform liquid coatings to pet food and other animal feed is a challenge that many processors are not sure how to address. Materials often stick together during coating, they aren’t coated evenly, the spray nozzles require too much maintenance, or the process simply takes too long. Upgrading your liquid coating system to a mistcoater can solve coating problems and speed up your process. Instead of using spray nozzles which easily clog  and only coat materials on one side, the mistcoater atomizes liquids using spinning disks and coats material evenly as it falls through the mist.

5. Micro Ingredient Automation

Hand-adding small amounts of ingredients is a temporary solution that can quickly become a permanent part of the feed or pet food processing system. This is also an inefficient and inexact technique that can quickly introduce errors, workplace hazards, complicate lot tracking, and disrupt the recipe. Automating this process will ensure uniformity and remove delays or hazards posed by hand-adding. Upgrade to a micro ingredient automation system and your micro ingredients will be a seamless addition to your overall recipe.

6. Reprogrammable Controls

When mixing times change, micro ingredients are added, or processes change, your computer or PLC is the one to control those changes. Often, that means rewriting the logic using the manufacturer’s proprietary code, often requiring a visit from a technician. If a number of automation upgrades are on the horizon, you can save time with a reprogrammable logic controller with a user-friendly interface.

7. Super Sack Unloader

If your daily ingredient usage exceeds 250 kg, whether for major or minor ingredients, upgrade to a super sack unloader instead of individual bags. This will not only decrease packaging and materials costs, but it will also improve efficiency and reduce workplace hazards with the proper super sack unloader design.

 

As you consider the best process automation improvements at your feed or pet food processing plant, start with the processes that take the most time, introduce the most error, or repeatedly create downtime and maintenance costs. You’ll see the greatest benefits from correcting these issues first, and this will pave the way for achieving optimal system production later on.

11 Super Sack Handling Precautions to Prevent Injuries

The increased use of super sacks in feed and pet food processing has saved operators hours in time, reduce costs, and helped to dramatically improve efficiency. A one-ton bulk bag (AKA super sack, flexible intermediate bulk container or FIBC) can take the place of forty fifty-pound bags. However, the growing popularity of super sack unloaders also introduces workplace hazards. If you are considering switching to bulk bags, make sure you have the right bulk bag unloader design, and the right super sack handling precautions in place.

Super Sack Handling Precautions in Receiving  

Super sacks are highly durable, and built and tested to carry up to 1 or 2 tons of material, however they can be damaged by improper handling or misuse. A few precautions and clear handling instructions at the receiving and loading stage can prevent many injuries later on.

1. Inspect the bag

When you receive the super sack or bulk bag of materials, do a brief inspection to ensure the bag is not damaged. In particular, look at the seams and the handles. This not only helps to prevent injuries that could occur from falling or breaking bags, but will also help to prevent product loss and expenses.

Get the secrets to feed mill and pet food automation systems design. Download the Engineer’s Guide to Weighing and Batching >

2. Careful forklift operation

Bulk bags should only be handled by a qualified forklift operator. To prevent the bag from tearing during loading and unloading, use a forklift with rounded or square tines, not sharp tines. Since most bulk bag injuries result from breaking handles, the operator should also take care during loading.

This procedure should be clear, and safety at this stage should be a priority. Instead of driving the forklift tines into the handles, the operator should manually place the handles onto the tines, drive forward, and then place the next set. Though this will take more time, it is an important measure to prevent damage to the handles and thereby also prevent injuries.

3. Alternative lifting mechanisms

Bulk bags are often shipped on a wooden pallet, so they can be lifted from the bottom. A lifting frame on the fork truck or attached to a hoist can then be used to attach the four bulk bag straps to the four hooks under the frame. Then the lifting frame can life the bag into position, or the fork truck can lift and set the bag by positioning it on top of the bulk bag unloading frame.

Super Sack Handling Precautions in Loading

4. Clear the area

Loading the bulk bag onto the discharge station is also a careful process, as this is where most injuries occur. When loading the bulk bag, no one should ever be underneath the bag at any time. This is especially important if you are using a hoist to lift the bag into position. The most common injuries occur when either the handles or the frame fails and the bag falls on a worker. This can kill or seriously injure personnel. To prevent this, the hoist should function without the need for a worker to guide or adjust the bag, and the area underneath the bag should be clearly marked.

5. Use a tried and tested frame

The frame supporting the bulk bag as it is loaded and discharged should also be strong and stable enough to support the system in the long-term. If the bulk bag often loads improperly and it is crooked or not properly supported, the weight will distribute unevenly on the frame, causing it to bend and eventually break.

Super Sack Handling Precautions in Discharge

6. Untie the bag, don’t cut it

When discharging the bulk bag into the system, there should be minimal contact between the bag and the operator. In some cases, a worker may cut the bulk bag spout with a knife to discharge it, however this introduces unnecessary risk. Instead, the bag and the spout should be untied and pulled into place.

7. Control dust

If the super sack materials are dry or they pose a dust fire risk, it is especially important to control fugitive dust during discharge. There are a number of ways to do this, and which is best will depend on your materials, facility, and the bulk bag frame design. You might use a spout seal, iris valve, or a ventilation system to control dust.

8. Control static

If dust does become a problem around your bulk bag unloader, a dust fire can occur even without an obvious trigger like a spark or arc. As the materials, especially powders, flow out of the bag, they create static charge. If a static spark reaches a dust cloud under the right conditions, it can explode. While mitigating dust, it is also important to ground the super sack unloader frame to prevent static buildup. By reducing the risks of both powder and static charge, you dramatically reduce the chances of dangerous powder explosions.

9. Eliminate pinch points

Finally, where the bulk bag spout and the valve or seal meet, make sure that workers are not exposed to pinch points or crushing. The care that you used to prevent dust fires can quickly be undone if workers can reach into spout-sealing systems or bag-elongating systems and injure themselves.

Super Sack Handling Precautions During Disposal

10. Don’t reuse the bag

In some cases, super sacks may be reused in other processes. While this is more environmentally friendly and can cut down on packaging costs, this method should be used with care. Reusing bulk bags can introduce cross-contamination, and it can damage the bag. Only reuse bags that are tested for this purpose, and only when cross-contamination isn’t an issue. Many suppliers offer recycling programs for bulk bags to make your operation more environmentally friendly without the risk from reusing the bags.   

Super Sack Handling Precautions in Storage

11. Store bags securely

If you receive multiple bulk bags at one time, you should also exercise caution about storage. Improper storage, can damage the bag and cause it to fail, or the bag could be punctured and material can be lost. If bulk bags are stored on top of each other to save space, use a racking system designed for this purpose. Never stack super sacks on top of each other.

Considering workplace hazards when you install your bulk back system will prevent injuries from happening later on. With proper super sack handling precautions from the start, you can take advantage of reduced costs and increased efficiency, while maintaining a safe workplace.

Part 2: Ingredient System Planning Pitfalls For Micro-Ingredient Scales, Conveyance and Controls

In the previous post, we discussed common problems that can occur with the start of a micro-ingredient system, including ingredient bins and feeders. The latter half of the system is generally more complex, and more issues usually arise here. In this blog post we’ll cover micro-ingredient scales, conveyance and controls, and what you can do to design the most effective system.

7 Ingredient System Planning Pitfalls for Micro-Ingredient Scales, Conveyance and Controls

1. Miscalculated Scale Error

To find the right scale for your formula, you’ll need to to add all of the possible ingredients and the quantity of each. This will tell you the size of the scale that you need, but you also need to consider the margin of error. If the scale can accurately measure within +/-5 grams and the required accuracy of the formula is 1%, you won’t be able to measure 10 grams of a micro-ingredient, because the possible error will be 50%.

Reduce error and improve efficiency. Download the Engineer’s Guide to Weighing and Batching >

2. Miscalculated Resolution and Accuracy

The scale resolution is also important to consider. The minimum increment a scale will display is generally one 10,000th (1/10,000) of the total scale capacity. So, a 100 kg scale would display in increments of .01 kg. If this isn’t suitable for your accuracy measurements or your feeder output, you may have to reconsider your scale capacity. Using the 100 kg scale example, if your feeder puts out more than .01 kg of material a second, and the control system can only time shut-off to within a second, the system will be inaccurate by this amount.

3. Incorrect Scale Hopper Design

The type of materials, the available height in the facility, and the downstream conveyance must all be considered to design the right scale hopper. Limited vertical space in some facilities can prevent the use of some types of scale hoppers, like a conical scale. Use of a roll-over tub with a slide gate may be a better choice then for facilities with lower ceilings. However, since a roll-over tub discharges material all at once, this will only work if the downstream conveyance or next process can accommodate all materials. If your materials are better suited to pneumatic conveying, like fine powders, then a conical scale hopper will transition into the pneumatic system easier. If you prefer to skip conveyance and discharge into the mixer, a conic scale hopper or roll-over tub will work.  

4. Cycle Time Doesn’t Match Mixer Time

For the micro ingredient system to reach maximum efficiency, the cycle time of each ingredient—including the time it takes for the materials to fill, settle, and discharge—must align with the batch mixing time of all ingredients. If, for example, it takes 30 seconds to fill, measure and discharge each ingredient in a 10 ingredient mix, it will take 300 seconds total to weigh the material in the scale so the mixer could be waiting for the weighing process to complete. If the mixing time only takes 150 seconds, it will be idle half the time. To solve this problem and reach maximum efficiency, you might use two scales, each with 5 ingredients.

This will require some careful calculations, as the fastest cycle time time, average time, and slowest time will vary. The times for each ingredient will also vary by density and amount. Be sure to allow some room for timing variation.

5. Vibration Interference

Vibration can be used  i in a micro ingredient system to prevent bridging, ratholing, and other no-flow conditions in bins and hoppers. It’s also desirable to keep the different parts of your system close together to prevent the need for extraneous conveyance. However, if scales are placed too close to vibrating equipment, it can cause fluctuation of the scale reading. If the scale readings are dampened to eliminate the fluctuating readout, the scales may appear to be working normally and showing normal readouts, but the process duct may be weighing  incorrectly. In this case, interference through vibration may be to blame.

6. Conveyance Contamination

The most efficient type of conveyance is through gravity, however this is not always an option, especially for facilities with low vertical clearance. In these cases, you might use pneumatic, belt or drag conveyors. When using belt or drag conveyors, it’s important to prevent contamination from one batch to the next. Materials, powder or coatings that become stuck on the belt can not only damage the belt and cause it to stick or slide, but can also contaminate new material. Use scrapers or brushes to prevent material build-up on the conveyor. It may also be advisable to run a flush material through the conveyor to clean off the residual material.

7. Slow or Damaged Controls

The micro ingredient system cannot function properly without direction from the right controls. The control system, whether you are using a PLC or PC, should be able to sample each scale quickly and stop feeders without a long delay, otherwise overfilling will ruin the batch. The system should also be powerful enough to control all scales, feeders, mixers, metered liquids, and other functions with accuracy. Finally, the control system should be enclosed if dust, moisture, heat, vibration or other hazards are a concern. Often, a PC will be used outside the factory floor for extra processing and data storage power, and communicate with a more durable PLC directly controlling equipment.  

With different ingredients and recipes there are different challenges for each part of the micro ingredient system. If you have questions about the needs and capabilities of your micro ingredient system or ingredient automation system, take a look at the Engineer’s Guide to Weighing and Batching. This guide addresses the issues from this and the previous blog post in more detail, as well as many others not discussed here.

Part 1: Ingredient System Planning Pitfalls from Micro-Ingredient Bins to Feeders

Proper planning before an ingredient system redesign or new installation is pivotal to ensure the system runs efficiently.  With so many moving parts and considerations, it’s not easy to plan for every eventuality, and a few problems are consistently missed. In this blog post, we’ll cover some of the most common problems that can arise at the start of the system with your micro-ingredient bins and feeders.

6 Ingredient System Planning Pitfalls from Micro-Ingredient Bins to Feeders

1. Incomplete, Inaccurate Information

Proper planning starts with accurate information. When your numbers are exact and you have all the information you need on your ingredient system up front, every step in the process will be easier. Whether you are installing a new system or conducting an ingredient system redesign for automation, you will need key information about all of your ingredients. You will also need information about your new or existing facility. Finally, you’ll need some measurements about your recipe as a whole to bring your system together properly. It’s helpful to have all of the following information available and well-organized in a spreadsheet:

  • Number of ingredients
  • Recipe composition
  • Ingredient types
  • Ingredient bulk density
  • Minimum weight required
  • Maximum weight required
  • Daily usage
  • Weekly Usage
  • Monthly usage

Get the secrets to feed mill and pet food automation systems design. Download the Engineer’s Guide to Weighing and Batching >

2. Insufficient Ingredient Storage

The usage of each ingredient as well as the delivery means and schedule will both play an important role in determining ingredient storage needs. For micro-ingredient systems and ingredients delivered infrequently, this will be particularly important for planning the rest of the surrounding system. If the daily usage of any ingredient exceeds 250 kg, consider using a super sack unloader to improve efficiency. For this, you’ll need adequate vertical space or design solutions to ensure ingredients flow properly.

3. Flow Problems From Bin Design  

You want to make sure that you have space for all ingredient bins of the correct size, and it’s also important to consider the construction of the bins themselves. Micro-ingredient bins without sloped walls, or without an adequate slope, can introduce flow problems. Generally, an angle of 70° is sufficient, but this will also depend on the characteristics of the ingredient. Ingredients that tend to clump, stick, or don’t flow freely may need additional design considerations, like vibration. If ingredients aren’t flowing properly from the bin, it can create costly downtime and other problems further downstream.

4. Contamination From Bin Design

Sometimes, when ingredients do not flow from the bin properly, the material may stick to the sides or stay in dead zones. When new shipments are loaded into the bins, this can introduce contamination. If the material in the bin becomes rancid and then mixes with a new batch, it will upset the quality of the product. Special coatings inside the bin can further enhance flow and reduce sticking and dead zones, and stainless steel will allow the bin to be easily cleaned at regular intervals.

5. Incorrect Feeder Type

Knowing the maximum and minimum weight for each ingredient, as well as ingredient characteristics, will be particularly important for choosing the right feeder type. You might choose an auger-type feeder for powders or other ingredients that won’t easily break or generate heat through friction. If the materials are susceptible to these problems, use a vibratory feeder instead.

6. Inaccurate Feeder Output

Both auger-type feeders and vibratory feeders must feed ingredients through the system with the proper output. The desired feeder output will vary depending on the accuracy needed and the total volume of the system. Here it is important to have accurate density measurements, as the material density will affect output calculations by weight. Output may also be affected by flushing if the ingredient is free-flowing. Use a knife gate or butterfly gate to prevent this problem.

 

Problems with ingredient bins and feeders are often overlooked, as these parts of the system are generally simpler than mixers, scales, and controls. However, problems anywhere in the process can affect the end result. Our next post will cover common issues with the later half of the micro-ingredient system, including scales, conveyance and controls.

7 Ways Feed Mill Automation Drives ROI

feed mill automation ROI

In any industry, automation is based on goals: solving problems, minimizing risks, and reducing costs. The same is true for feed mill automation. There are a number of ways that feed mill automation can improve the end product and solve or reduce problems throughout the operation. Though some facilities may automate all processes at once, step-by-step automation is also a viable option. Feed mill automation can drive ROI in the following ways, and many of these benefits may occur simultaneously, depending on which process or processes you choose to automate.

7 Ways Feed Mill Automation Drives ROI

1. Reducing Labor Costs

Automation not only ensures that tasks are completed consistently, but also eliminates the need for manual operation. Repetitive tasks no longer require physical labor, and free up manpower for more sophisticated and important jobs. Automation can also protect workers from safety risks, either by removing them from dirty or dangerous environments, or by putting reliable safety controls in place.

Reduce error and improve efficiency. Download the Engineer’s Guide to Weighing and Batching >

2. Enhanced Production

Enhanced production is one of the most common factors driving ROI in feed mill automation. With the right design and maintenance, automation can streamline processes and remove the need for breaks and pauses. The right machines can also work at a faster rate.

3. Measureable Regulatory Compliance

Feed mill automation can simplify regulatory compliance for rules like the Food Safety Modernization Act (FSMA), among others. Track and trace is an important part of FSMA compliance, but can be difficult to accurately implement without systematic controls. Tracking lot numbers manually not only introduces error, but takes up workers’ time and energy. Lot tracing can easily be automated, and it will greatly improve accuracy. With a reliable, automatic system in place tracking where your ingredients came from, what they went into, and where the product ultimately went, you can reduce liability and meet compliance requirements with minimal costs.

4. Consistent Testing

To prevent moisture, toxins and other substances from ruining ingredients and the finished product, proper sampling and testing is essential. With automated sampling and testing, you can gather uniform, accurate information about ingredients and products. Detecting excessive moisture in ingredients from the start will prevent product from being contaminated, and allow you to hold suppliers accountable for defects. Detecting aflatoxins and other harmful substances in ingredients also reduces liability, as well as product loss. With feed mill automation for testing and sampling combined with automated track and tracing, any problems with ingredients or products can be accurately recorded.

5. Reducing Batching Errors

Batching is one of the most common areas for feed mill automation, and often offers the highest initial ROI. By automating your batching and mixing processes, you can substantially reduce error and variation. When your recipe is programmatically controlled, corn, soy, vitamins, minerals, enzymes and other additives are each exactly measured. With an easily re-programmable controller, you can even change the recipe without significant downtime.

6. Automatic Routing

Automation of the batching process is usually the first section of the feed mill to be automated, but the addition of downstream routing of material can enhance the payback of the system. If the system has to wait for the operator to setup the routing of material to the downstream packaging or load-out, then valuable production time can elapse while waiting for a route to be selected.

7. HACCP

Through most zones, feed mill automation makes hazard analysis and critical control points easier to regulate and monitor. By gathering more data, more often, with less manpower required, you can get holistic, up-to-date information about your production line. You can also eliminate risks altogether by automating repetitive tasks with a high risk of human error. Automated regulation ensures that critical control points are monitored at the same time, in the same way, with no exceptions.

Before starting or continuing feed mill automation, plan and design your system carefully. Conduct ingredient testing to ensure that the system is suitable for your recipe, and be sure to factor any maintenance costs into your ROI calculations. With the right system automating the right process, you can realize a return quickly and eliminate risks at the same time.

How to Optimize Your Ribbon Mixer

Ribbon mixers in many industries are designed similarly from facility to facility with few variations. However, some design considerations can minimize the up front investment and maintenance, and maximize production and quality. The best way to get optimal efficiency from your ribbon mixer is to get the right design from the start. Depending on your materials, environment and overall mixing system, there may be more to consider than you think.

How to Optimize Your Ribbon Mixer

Compile Ingredients List

Your ingredient characteristics will play a role in several ribbon mixer design elements, and starting with this information will help your equipment manufacturer optimize the design. This way, you will have the size and features you need, without expensive extras. What characteristics you include will depend on whether your ingredients are solid, powder, liquid, or paste. For solids, it’s helpful to know any of the following that apply:

  • Number of ingredients
  • Names
  • Bulk density
  • Weight
  • Particle size variation
  • Adhesion
  • Friability
  • Shear sensitivity

Design the ideal system for your ingredients. Download the Engineer’s Guide to Weighing and Batching >

Record Facility Requirements

In some facilities, space may be a concern. This will impact the footprint and profile of your mixer, which in turn affects volume and production. If you require a large 8 or 10 ton ribbon mixer to meet production, be sure that this will not crowd out other equipment or create workplace hazards.

Calculate Total Production

How much you need to mix will help you determine the size and profile of the ribbon mixer design, or how many mixers you may need. This way, you aren’t investing in a larger mixer than you need, or one that doesn’t make sense with your total cycle time.

Determine Mixing Time

Your ingredients generally must move through the mixer completely three times to be adequately mixed. How long this takes depends on the ribbon mixer dimensions, as well as the ingredient characteristics. To be considered adequately mixed, you’ll need a coefficient of variation of 10 or less. Testing the mixer and the system with your ingredients beforehand will prevent excessive variation, while providing the ideal cycle time.

Record Weighing Time

Minimizing mixing time can yield efficiency gains, but not if the mixer sits idle while ingredients are measured. How long it takes to weigh and discharge ingredients will give you a guideline for the ideal mixing time. If your weighing time and mixing times are close to the same, you can minimize idle time for each process.

Accurate Agitator Profile Design

To get a good mix, you’ll need to fill the ribbon mixer to its swept volume. This means the agitator profile determines, in part, how much the machine can mix in one cycle. The mixer profile should not exceed 2.5 times the diameter of the agitator. The design of the agitator itself, including the ribbon thickness and shaft, may also be a factor, as a heavier agitator will require more energy to move and will have more shear. A simpler agitator design can reduce the initial investment if it’s suitable for the ingredients and facility.

Determine Ribbon Mixer Profile

With the previous information, you can determine the optimal ribbon mixer profile. Longer mixers will be able to mix more volume, but it will take longer, though this won’t be a problem if the cycle times aligns with the weighing time. For lower mixing time and more volume, you’ll need to scale up the ribbon mixer profile proportionately.

Number of Ribbon Mixers

In some cases, it may be more economical to use two ribbon mixers instead of one that is double the size. This way, a problem with one mixer will only reduce production instead of stopping it.

Liquid Coating Considerations

If your ingredients require a liquid coating, you may wish to apply it during the mixing stage. Keep in mind that some liquid coatings may not be evenly applied at this stage, or they liquid may not be suitable for spray nozzles. If the liquid coating can be applied during mixer, be sure to factor in any additional adhesion that may occur. If material stick to each other or to the mixer, extra maintenance may be required, which can eat into ROI.

Determine Shear

Ribbon mixers are generally gentle and impose little shear on ingredients, however it can be an important consideration with some shear sensitive materials. Consider any solid ingredients as well as liquid coatings; are they likely to break apart or separate? Do the ingredients require more shear to break up clumps? Most mixer manufacturers are happy to do testing in order to determine the best configuration for your product.

Accurate Horsepower

Most ribbon mixers operate at around 20 RPMs, though the horsepower it requires will depend on the size of the mixer and the characteristics of the ingredients. Make sure you don’t overestimate your motor and overspend, or underestimate your motor and reduce power to your ribbon mixer.

Install Proper Discharge Gate

The discharge gate on your ribbon mixer(s) will depend on your cycle time, downstream process and your materials. Drop bottom discharge gates will discharge quickly, but they can be harder to seal and allow powders to escape. This can be a challenge for very fine ingredients. Slide gates will discharge more slowly, but will seal more tightly. Multiple slide gates can provide a tight seal with faster discharge.

Reduce Maintenance

The type of gear reducer used in your ribbon mixer motor can impose unnecessary maintenance costs. A shaft reducer in lieu of a jack shaft or foot mount eliminates the need for an oil bath on the sprocket.

Some ribbon mixers are straightforward, and the mixer design varies little over time and throughout the industry. Others are more complex, and considering all the elements can help you improve the design. With the right ribbon mixer design from the start, your mixer will continue to work quietly in the background, with optimal efficiency and no problems.

Solving 5 Common Super Sack Unloader Problems

The right super sack unloader system allows you to measure and process materials quickly and cost-effectively, with very little waste, error or manpower required. Unloading materials may seem like a straightforward process, however the wrong bulk bag discharge system can cause product defects, ingredient loss, and pose workplace safety hazards. The ingredients you’re using as well as the design of your system and the volume processed will all play a role in choosing a safe, effective, durable super sack unloader.

5 Super Sack Unloader Problems and Solutions

1. Design for Space

The first thing to consider with your super sack unloader is the design, which will depend on how you transport the bulk bags, and the design of your facility. Your bulk bag unloader design may be any of the following:

  • Forklift: If you are transporting the bag from the top using a forklift, this will most likely be the easiest and simplest option. This allows a forklift operator to easily load the bag into the frame from the top, with no other steps required.
  • Dedicated Hoist: In some cases a clear path may not be available for a forklift. A dedicated hoist design allows you to secure the bag to support arms and lift, then push it into place. With this design, it is important to motorize the lifting and pushing mechanism to put the bag in place.
  • Bottom Lift: Facilities with low clearance, such as those retrofitting from individual bag unloading, may use a bottom lift mechanism. With this design, a forklift operator can move the super sack and support frame from the bottom and lift it into place with only about half the height needed.

Keep in mind that staff should never be below the bags at any point while loading the bag, as this presents a serious workplace hazard. Though bulk bag failures are uncommon, they do occur.

2. Preventing Bag Deformation

As the ingredients flow out of the bulk bag, it will begin to lose its shape and ingredients will flow slowly, or even stop. There are several ways to stop flow problems, and which you choose will depend on the ingredients you are using and the design of the super sack unloader.

  • Raise the Bag: With vertical clearance available, you can lift the bulk bag support arms as the bag unloads, increasing the flow angle.
  • Retractable Arms: If the arms supporting the super sack are spring-loaded, they will retract as the bag loses tension. This maintains the flow angle.
  • Paddles: Pneumatic paddles at the bottom of the bag can push the ingredients up as the bag discharges. For ingredients with low flow, or for sticky materials prone to clumping, paddles and other flow aid devices are useful.

3. Accounting for Material Characteristics

The characteristics of your materials are also important to consider when choosing your super sack unloader. Some materials are more susceptible to flow problems or segregation, which can cause other problems in the process. How the material flows, its moisture content, whether it is prone to static charge, clumping or flushing, and other characteristics will decide what type of special features your bag unloader may need to be effective.

  • Flushing: Dry, light, free-flowing materials may have a tendency to flush, continuing to flow after shut-off. Pay special attention to the valve or gate below the bag to prevent flushing.
  • Dust: Dry, light materials also tend to produce dust. A ventilation or vacuum system may be required around the bulk bag unloader to prevent dust build-up and workplace safety hazards. When the bag is empty, dust can be trapped inside, so it is also important to tie the empty bag before removing it.
  • Clumping: Adhesive materials may form clumps within the bag, or the bag may become solid if it is compressed. In some cases, a bag liner preventing moisture can stop clumping. Pneumatic rams can break up solid blocks, or paddles can break apart clumps.
  • Static: Very fine materials as well as some plastic resins can become statically charged as they flow, especially in dry conditions. This can cause materials to stick to the sides of the bag or feeder and decrease the feeder capacity. The static charge can also pose a risk to scales, load cells or system controls. Make sure the super sack unloader frame is grounded to prevent static build-up.
  • Moisture: Some materials may need protection against moisture to prevent spoiling or clumping. A bag liner can prevent this, but the bulk bag unloader frame should also secure the bag liner to prevent it from becoming lodged in the feeder.

4. The Right Discharge System

To accurately discharge ingredients, you’ll need to choose the right discharge system using either loss-in-weight or volumetric measurement. Which method you choose will depend on the level of accuracy you require.

  • Loss-in-weight: With load cells mounted underneath the bulk bag base or frame you can measure discharge through the weight of the bag. This is suitable for ingredients in large amounts, but more accurate scales will be required for ingredients discharged at 40 lbs or less with 1% accuracy, based on a one-ton bulk bag.
  • Gain-in-Weight: For more accurate measurements, gain-in-weight measurement may be preferred. In this case, the scale be sized for the actual amount being weighed, so the accuracy can be adjusted to your needs.

5. Meeting Sanitation Requirements

If your materials must meet food grade or other USDA or FDA standards, you’ll need to make sure the super sack unloader and the bag itself are suitable. A bag liner is useful here to protect the materials inside from moisture, damage or contamination. In this case, the frame around the bag should secure both the bag and the liner, or the liner may collapse and enter the feeder. The frame, as well as any surface the materials come into contact with should be made from stainless steel to allow for easy sanitation.

 

With the right bulk bag unloader system, you can process materials quickly, safely, and efficiently. The best way to make sure your system works effectively with your materials, as well as your downstream and upstream processes, is to design and test it properly. Your equipment supplier can help you address these issues and make each part of your system efficient.

Complete Ingredient Mixing Systems Design Checklist

ingredient mixing system design

There is no one-size-fits-all for ingredient mixing systems design, whether you are working in snack foods, animal feed, dry bulk solids or any other industry. Ingredient mixing system designs require careful consideration of all ingredients as well as production schedules, variation, storage and more. In this blog, we’ll provide a basic roadmap for automated ingredient mixing system design that business owners, facility managers, engineers and others can easily follow.

Automated Ingredient Mixing System Design Checklist

Planning System Design Requirements

Your ingredient mixing system design starts with needs and goals, including your ingredients, production volume and product variation. The accuracy of this initial information will determine the design of the rest of your system, so it’s important to be as clear and correct as possible at this stage.

You’ll need all of the following information

  • Ingredients: number, names, bulk density, weight, ingredient delivery schedule, special considerations (friability, viscosity, adhesion, particle size variation etc.)
  • Production: daily, weekly, monthly amounts
  • Environment: temperature, humidity, seasonal changes

This information will not only help you design your ingredient mixing systems for volume and production, but will also help you avoid any complications that could arise from system’s surrounding environment, or challenges with the materials or ingredients themselves, such as material segregation or flow control problems.

Get the secrets to automation systems design. Download the Engineer’s Guide to Weighing and Batching >

Storage Bins

Your production volume, number of ingredients, and ingredient delivery schedule will help you determine the size and number of storage bins you will need. Consider the minimum and maximum production levels of your facility, as well as the minimum and maximum ingredient volume delivery for each ingredient to determine the storage bin size you will need. Also, consider any safety requirements you will need when unloading ingredients, or any special considerations the ingredients may need during storage, such as temperature requirements or bin coatings for acidic or adhesive ingredients.

Consider these factors as you design your ingredient loading and storage area:

  • Storage bin size
  • Storage bin placement
  • Unloading area
  • Unloading safety requirements
  • Bin coating requirements

Feeder Design

Feeders are one of the most important parts of your ingredient mixing system design. Designing your feeder improperly can cause incorrect measurement and mixing, resulting in product defects, or slow-downs and downtime when ingredients don’t move through the feeder at the desired rate.

The maximum and minimum weight of each ingredient you determined in the planning stage can help you determine your feeder volume output. The feeder must be able to feed the smallest micro-ingredients as well as high-volume base ingredients, all within tolerances. This may mean installing multiple feeders or installing additional features on one feeder, such as speed controls. You’ll also need to determine your feeder drive mechanism, either hydraulic or electric, as well as a cut-off valve to prevent flushing.

To get the right feeder, consider the following:

  • Feeder volume output
  • Number of feeders or features
  • Feeder drive
  • Feed cut-off valve
  • Accuracy

Scales

To properly design and install scales for your ingredient mixing system, you’ll need to determine the maximum and minimum number and amount of ingredients you’ll be measuring, as well as how accurate the measurements must be. Remember that scales, like feeders, must be capable of meeting volume and accuracy requirements for micro- and macro-ingredients. This means they should be large enough to handle heavy volumes, but accurate enough to measure micro-ingredients without too much error. If there are large variations between your ingredients, using several scales or diluting ingredients can help you maintain accuracy.

The type of scale you choose will also have a dramatic impact on the system at large. The right type of scale can help you save time and eliminate extra processes, like a conveyor scale, make mixing easier and more uniform, like a conical scale hopper, or integrate with a variety of bins, like a roll-over tub. The best scale type will depend on your facility, ingredients, and product.

You’ll need to know the following:

  • Maximum scale weight
  • Maximum scale error
  • Number of scales
  • Scale inclusion rate
  • Scale display resolution
  • Scale type

Mixer

It’s important to choose a mixer that will properly mix all ingredients together, but will also give you an efficient cycle time. You’ll need to measure the cycle time of your mixer and compare it to the cycle time of your weighing and discharging system for maximum efficiency. This will allow you to run all processes simultaneously, instead of leaving your mixer or feeders idle. You’ll also need to consider any special requirements of your ingredients, such as adhesion, friability or heat and shear. Finally, remember that the mixer must be filled at least to swept volume to work properly, so all ingredient mixes, including the lowest possible volume, must fill the mixer at least to swept volume.

Consider all of the following for your mixer:

  • Mixer cycle time
  • Mixer footprint and profile
  • Mixer swept volume
  • Ingredient considerations

Controls

Without the right control system, even the best ingredient mixing systems designs won’t work. Your control system keeps you automated system running smoothly, and alerts you to any problems. You’ll need to choose a computer or PLC that integrates easily but completely with your system design. This means your controls must be able to work with all of your inputs and settings, including multiple feeder or mixing speeds, scales, sensors, and all upstream or downstream functions.

Keep in mind that your system, ingredients and recipe may change, and your controls may need to be reprogrammed at some point. The best control systems will adapt to your needs without the need for complex programming knowledge.

To get the right controls you’ll need to know:

  • Number of scales
  • Number of feeders
  • Number of mixers
  • Variable speed controls
  • Sensors and alarm conditions
  • Upstream or downstream processes
  • Reprogramming conditions

To complete your system, you’ll also need to consider upstream and downstream processes, which may vary depending on your ingredients, ingredient delivery system, and batching process. At each point in the process, your environmental conditions will also be a concern, as high temperatures or humidity can cause materials to separate, stick, or flow slowly. As you design and build your system, work closely with your equipment manufacturer to make sure your system is build for your ingredients and volume.