Today’s dairy industry faces several challenges. Plant-based products, like almond and soy milk, are altering the traditional product lineup. The varieties of products are growing rapidly, with the explosion of choices in the yogurt, milk, and ice cream aisles. In addition, the dairy industry finds itself dealing with rapid shifts in consumer preferences requiring greater flexibility in processing and packaging. There are also increasing financial pressures stemming from production capacities, the overall farming economy, and labor shortages.
At the operations level, there are several concerns. Dairy processors need equipment that allow them to meet the highest standards of cleanliness. Pneumatics has a long history in the dairy industry, with applications that vary widely from cheese and butter making to yogurt and drink production. On the processing side, a single piece of dairy mixing and blending equipment could have 40 or more hygienic process valves that help control the flow of raw ingredients. In the packaging area, pneumatic devices like piston valves, manifolds, and cylinders are located on most equipment, providing actuation or motion control. In today’s challenging environment, pneumatics technology offers many critical advantages.
One of the most important aspects in a dairy operation is cleanliness, especially in meeting regulatory standards. Pneumatics offers an advantage in helping to ensure equipment meets the hygienic standards of all the regulatory bodies, like 3-A Sanitary Standards Inc. (3-A SSI) in the U.S. and EHEDG, the European Hygienic Engineering and Design Group.
Started largely for dairy certification more than a century ago, 3-A SSI now applies to a variety of different food and beverage processes. The 3-A standard is rigorous, requiring that any seals touching the liquid not harbor any pathogen or bacteria. They must be highly cleanable and able to withstand high temperatures. There can be no grooves or crevices, with a maximum allowable surface roughness of just 0.8 micrometers.
Electrically actuated valves would require a specific design change or to be placed in an enclosure to meet washdown requirements, which adds cost and takes up valuable floorspace, so they are not commonly used in the process area of a food or dairy plant. Pneumatic equipment, on the other hand, is ideal for work in hygienic or rugged environments where frequent washdowns are required. In high-temperature, high-pressure washdown applications, some pneumatic directional control valves feature hygienic design, the ability to withstand aggressive detergents and chemicals, plus a high degree of modularity and flexibility for operational benefits. For dust-off or light washdown uses, for example in secondary packaging or handling applications, some companies like Emerson provide air cylinders that meet FDA, NSF, and ISO 6431, 15552, 21287 standards and feature a clean profile design to minimize potential pocket areas where dirt and contaminates can collect.
Dairy processors need equipment that has a high level of modularity so they can react to rapidly changing consumer preferences. Pneumatics offers quick setup and easy changeout, giving dairy operations the ability to upgrade, fix, replace, or quickly change the parameters of their equipment.
For instance, one machine may be used to fill 6-, 12-, or 18-ounce containers with different products. This requires machine components that can adapt quickly to the different container sizes depending on the product being processed. This could be more relevant for packaging operations, where dairy processors can expect a lot of rapid cycling on the packaging line—for example, as single-serve containers change over to club-size containers.
Being able to adapt efficiently with minimal downtime helps increase overall equipment effectiveness. In some cases, by simply changing the machine’s automation program accordingly via the controller interface, the pneumatic functionality can readjust automatically based on the requirements for the new product run.
Because pneumatics equipment avoids some of the complexity inherent in other power technologies, it’s known for dependable operation with less downtime. It’s also easy to fix, keeping maintenance costs low. It simply needs to have clean air. Built to work in a production environment, pneumatic devices also have a long-life expectancy, completing millions of cycles and withstanding high actuation rates.
In addition, pneumatics technology is well-positioned to utilize Industrial Internet of Things (IIoT) capabilities. New IIoT edge devices can collect data from the pneumatic system to identify leaks, monitor energy usage and air consumption, and calculate the life expectancy or mission time of a pneumatic component. For example, by using appropriate data from an IIoT gateway device, maintenance technicians can predict that a shock absorber at the end of an actuator is deteriorating just by sensing an increase in its stroke speed, even if only by a few milliseconds. By knowing which equipment needs maintenance before it actually fails, plant engineers can avoid unplanned machine downtime and replace defective components with shorter and fewer machine stoppages.
Pneumatics equipment can handle high-speed production or high-speed motion sequences, using valves engineered for high actuation rates. Pneumatically operated pilot valves can be used throughout the facility to actuate a variety of critical on/off process valves and packaging equipment. They’re used extensively in packaging lines where weight and high cycling are critical. They perform in short to long strokes in a variety of operating conditions from high temperatures and high pressures for aggressive washdowns. Plus, they have high shock absorbance.
Pneumatics technology generally has a lower initial cost than electronics on a component versus component basis, and is extremely cost-effective in operation, routinely saving operational expense because of its energy efficiency, reliability, and low maintenance costs. While electric devices may offer more control, that added capability may not be as relevant in food and dairy processing as it is in other industries. In addition, pneumatic technology is more washdown -friendly than electrical devices, which need a temperature-controlled environment to avoid overloaded circuits.
Compressed air is usually available throughout a dairy plant, so connecting more devices when needed for a new application usually results in little incremental cost. In fact, the more pneumatics connected to a compressor and the closer the total demand is to the capacity of the compressor, the more efficient pneumatics becomes. Conversely, a smaller number of pneumatic components using a smaller portion of a compressor’s capacity would be less efficient in operation. That’s why it’s best to evaluate costs on a case-by-case basis.
Pneumatics can help address plant safety issues in several ways using a proven technology (compressed air). As a result, dairy producers hoping to comply with ISO and other regulatory standards have a wide range of traditional pneumatics products to choose from.
For example, Emerson is advancing an integrated, scalable zoned safety approach, allowing up to three safety zones to be isolated on a machine from a single pneumatic assembly. With zoned safety, the valve manifold can be configured to shut down pilot air and power only to the control equipment that will come in contact with the operator. The rest of the machine can remain in operation. Zoned safety helps design engineers satisfy Machinery Directive 2006/42/EC and comply with ISO 13849-1 and ISO 13849-2. It reduces the number of safety system components by up to 35 percent, requires fewer connections, and saves valuable real estate within the machine and manifold.
Compressed air is normally available throughout the typical dairy processing facility, so dairy processors can deploy pneumatics almost anywhere in the plant. And, at a deeper level, pneumatic devices prove their versatility by communicating across a wide range of industry protocols, like Ethernet-based protocols, Open System Interconnection (OSI), and IO-Link, and even Process Field Bus (PROFIBUS) and DeviceNet. As a result, it’s easier for dairy processors to use pneumatic devices that comply with national and international standards, anywhere in the world.
This high level of flexibility has allowed the dairy industry to deploy pneumatics in a widespread fashion. Equipment designers are learning to specify pneumatics quickly and easily, helping dairy machine OEMs meet end-user requirements for machines that are faster, more efficient, or consume less energy or air. Dairy processors are deploying pneumatics throughout their plants, reducing ramp up and training time required when they introduce new equipment. Dairy plant workers are developing a high level of familiarity, learning how to operate and maintain pneumatics equipment and controls.
Plant Engineering Advice for Implementing Pneumatics
There are several key best practices to follow when implementing pneumatics in a dairy operation:
- Mount the valves close to the cylinders to avoid long air lines and wasted energy.
- Mount the cylinders so they can be easily cleaned.
- Decentralize valve manifolds on larger production lines.
- Size pneumatic systems for optimal performance to avoid wasting energy on compressed air.
- Ensure the air pressure is constant to maintain optimal actuator cushioning by placing the regulators close to the actuators.
- Filter the compressed air according to the applications for which it is being used. If possible, place filters by each valve manifold.
- Lubrication for pneumatic components generally may not be needed, but if it is, be sure to use food-grade (type NSF H1) lubricants.
Pneumatics offers abundant advantages to dairy processors. Pneumatic devices can handle the rigors of a dairy’s rugged washdown environment. They’re easy to upgrade or change, giving dairy operations the flexibility to respond to changing consumer preferences. They can be used almost anywhere, tapping into compressed air that’s available throughout the plant. Finally, pneumatic technology can help dairy operations comply with regulations, protect workers and equipment from harm, and help maintain a high level of production and minimize downtime through predictive maintenance.
Patel is a product marketing manager at Emerson. Reach him at email@example.com.
Pneumatics Improve a Cheese-Making Operation
Cheese products are processed batch to batch in an environment that requires frequent washdowns involving a lot of solids. If there’s an accident, no toxic chemicals or contaminants can touch the food.
For certain hard cheeses, raw product is formed into round wheels, called fascere, that can weigh almost 90 pounds each. The wheels are dipped in brine for three weeks and allowed to mature for at least a year in air-conditioned storage. The back-breaking process of forming, turning, pressing, and molding the cheese is often done manually.
One Italian cheese-making equipment provider, Progema Engineering S.R.L., is working to automate the heavy lifting. The company is using corrosion-resistant, double-acting pneumatic cylinders to move the blocks of cheese, which are saturated with liquid. The Emerson AVENTICS washdown CL03-EV directional control valves are installed directly on the machines, with actuators in decentralized locations so that compressed air lines are shorter with no dead volumes or pressure losses, thereby reducing air consumption. The entire process meets food industry standards.
Additionally, the liquid whey pressed out of the wheels of cheese is now recovered. Formerly discarded, the whey is sold for use in protein powders and shakes, generating a new revenue stream for dairy operations.