Automated cleaning and sanitation saves time, produces better results
CIP and COP systems benefit from automated washing systems that make use of spraying equipment matched to the right chemical media.
With FSMA in place and many processors seeking GFSI certifications, effective cleaning and sanitation are more important than ever. Processors are concentrating on good sanitation practices, and they are getting help from automated equipment that can produce verifiable results and records, but the human element still remains—because not all sanitation steps can easily be automated.
A 2011 Canadian report published by the Food Processing Human Resources Council, “Trends and New Technologies Affecting the Work Performed by Sanitation Workers in the Food Processing Industry,” pointed out a common problem for small and medium-sized food processors: Sanitation workers in the food industry perform dangerous and tedious work with many unique challenges.1 Most cleaning and sanitation work is performed on night shifts in miserable and often unsafe industrial environments. The night shift workers typically receive less pay than others, receive little training and—because of the time they perform their cleaning operations—receive little if any oversight by senior management. Unfortunately, these often high-turnover jobs tend to attract the least-skilled people who may not understand that appropriate cleaning and sanitation are necessary to make safe food products.
In some applications (e.g., poultry), cleaning and sanitation chemicals have to be strong to rid surfaces of clinging biofilms, fats and proteins, and skill is required to handle the chemicals. Heavy soil loadings need strong chemicals and high temperatures to clean effectively, which spell danger for human contact. Consequently, processors should have safety programs in place explaining bodily damage can be caused by chemicals through skin contact, skin absorption, breathing, eye contact and ingestion. In addition, workers must be knowledgeable about chemical usage, wear personal protective equipment (PPE) and observe safety rules and procedures. Therefore, processors should conduct regular chemical safety training sessions.
Sustainability and safety work together
While FSMA is certainly an important consideration in cleaning and sanitation practices and the use of chemicals, other factors are just as critical. “Currently, companies focus on cost-effective sustainability in their choice of chemicals, in addition to efficacy and equipment compatibility,” says Henry Dao, HSP USA president. While there have been advances in technology such as nano-silver-based compounds, their high cost and narrow application scope have limited their use. “Super-oxidized water is a multipurpose [technology] and fit for use in many applications,” adds Dao. “It is fast acting yet pH neutral and gentle on equipment and humans. With FSMA, it is better to have a fewer number of chemistries in use, which simplifies operations as well as regulatory requirements.”
According to Ecolab’s Sustainability Report 2012 (published in the mid-2013), simplifying chemistries is an important trend. Ecolab helped Arla Foods move from energy-intensive, high-temperature processes with many steps to lower-temperature processes with fewer steps. One goal was to optimize water consumption, decrease energy usage and reduce product waste. Another was to decrease the use of harsh chemicals that can be dangerous to people and the environment. Through the use of Ecolab solutions like Excelerate, CIP Diagnose and Cold disinfection, Arla reduced time, energy, water and product waste. With Ecolab’s support in 2012, Arla saved a total of 731 million liters (193.1 million gallons) of water, 17 million kWh of energy and 665 cubic meters of chemicals and raw materials.
Some important trends in sanitizers involve both safer chemicals and verifying they work or are effective in killing bacteria, molds and viruses. Gabe Miller, Sani-Matic senior technical engineer, lists three trends he has seen:
1. Onsite electrochemical (ECA) generators are being used to produce caustic and hypochlorous acid sanitizer from common salt. The sanitizer has been approved for use under the PMO. However, the caustic must be tested to confirm its effectiveness on various food residues. But where it is effective, ECA systems can significantly reduce the cost of cleaning and sanitizing. The solutions generated by these systems are also much safer to store and dispense, and eliminate the transportation of hazardous chemicals.
2. Peracetic acid (PAA) sanitizers are available with sufficient conductivity for the concentration to be more easily measured by conductivity. Now, plants can confirm the presence and concentration of the sanitizers and record the data electronically.
3. Foaming sanitizers are also available with increased contact time and efficacy.
One processor that has made effective use of the ECA technology is Coca-Cola. Pete Duessel, Coca-Cola Refreshments director of quality assurance, presented a business case for the use of ECA at PROCESS EXPO 2013 in Chicago. ECA technology from SPX has contributed to Coca-Cola’s “Live Positively” commitment to reduce water, energy use and environmental impact while increasing plant safety.
SPX’s APV brand known as SafeWater produces a cleaning solution of sodium hydroxide and a hypochlorous acid sanitizer by combining potable water with a small amount of salt and applying an electrical current. The fluids can be used at ambient temperature, reducing energy usage and lowering employee safety risks. The technology can be applied in cleaning and sanitizing processes in the food, beverage and dairy industries, according to Jeffrey Sporer, director-product and aftermarket sales, SPX Flow Technology—food and beverage.
While ECA systems are more costly to implement than their chemical-based counterparts, their cost of operation is much smaller, says Miller. “The sanitizer is effective on all clean surfaces at the correct concentration, the same as any other sanitizer.”
The caustic is most effective on light soils, such as those in beverage plants; however, ECA systems have also been used in other food applications, according to Miller. “But they do not produce acid detergents for the removal of mineral soils.” That’s why it’s important to test each cleaning application in advance until ECA is proven effective on the soils, adds Miller.
“Good applications for onsite generation systems are CIP, COP, cleaning and sanitization, deodorization, water and waste treatment,” says Dao. For onsite generation systems of super-oxidized water, the typical payback time ranges from six to 18 months. “This compares favorably to standard chemical sanitization systems, e.g., PAA. HSP’s customers cover the entire food and beverage chain including agriculture, food processing, food retail and service.”
While chlorine-based technologies are effective, some related issues exist concerning chlorine and excessive levels of sodium. “The principal trend we are seeing is away from chlorine chemistry in certain parts of the country [California] and a demand for sodium- or salt-free options due to concerns about salt or sodium levels in plant wastewater,” says Ellis M. Owens, Birko Corp. senior chemist/microbiologist. “There is some interest in the use of enzyme-based cleaners, which are gentler on equipment and personnel, but there are still potential limitations to their efficacy in removing soil. Switching to quaternary ammonium sanitizers maintains antimicrobial efficacy with a somewhat ‘gentler’ chemistry.” To date, FSMA has not affected chemical formulations, but changes to other regulations, such as EPA and California Prop 65 , which are geared toward removing toxic chemicals from the environment, are driving changes in cleaning formulations, adds Owens.
Other effective technologies
Many other technologies are suited to specific sanitation applications. For example, ozone (ozonated water) is an extremely effective sanitizer with a relatively weak concentration in water that does not generally pose a safety issue. But its high oxidation potential can create respiratory issues for humans if it is not handled correctly. “The concentration also is extremely difficult to control in atmospheric conditions such as tank sanitizing, because the ozone comes out of the solution very quickly when it goes through a spray device,” explains Miller. Also, ozone may be corrosive to a variety of materials, including many types of rubber gaskets, so applications must be reviewed carefully to ensure all the materials are compatible with the ozone, adds Miller.
However, when used with proper protocols, ozone is a safe and environmentally friendly sanitizing agent; it received FDA GRAS recognition in 1997 and was approved by an FDA final ruling for fruits, vegetables, seafood and certain meat products in 2001. It also was approved under USDA’s Organic Rule in 2000. Ozone easily breaks down to molecular oxygen, is pH neutral and leaves no byproducts or residues behind. It’s used in container sanitation, bottling lines and fillers, and processing and transfer equipment, as well as for surface sanitation.
One method for removing stubborn soils is analogous to sandblasting, but uses dry ice instead. While it is great for cleaning baked-on materials, it is not a sanitizer and, for that reason, presents some problems, according to Miller. When soils are removed from the surface by dry ice, they don’t go away—they are merely blasted off onto another surface. The system works only at close range, so it needs to be tested to verify its effectiveness at the distances and coverage patterns needed in an application.
Dry ice blasting systems are very loud, so hearing safety programs need to be in place. Plus, CO2 is an expendable product that requires extremely cold storage conditions and special handling, issues that must be factored into a plant’s operating costs. Finally, processors may want to compare the effectiveness of these systems to high-pressure water washing in the same application, especially in the area of allergen removal.
Applying chemicals and rinses
While passing cleaning and sanitizing chemicals through piping and pumps is a relatively routine CIP process today, the trend has been to automate the cleaning of vessels, tanks, mixing containers, conveyors, etc.—and for good reasons: to provide adequate cleaning and sanitizing coverage on a consistent basis, and to have verifiable results. It may have been a typical practice in the 1950s—though not safe—to climb inside a large butter churn and spray wash it manually, but there was no guarantee of adequate coverage for every square inch of the vessel—nor was it easy to verify the entire interior surface was free of bacteria.
Automated spraying machines for COP applications have many advantages. “They save water and chemicals by recirculating wash water,” offers Kevin Lemen, Douglas Machines vice president, sales and marketing. “They also save on labor costs by reducing man hours. Large vats and bins are difficult to handle and, all too often, lead to Workers’ Comp claims. The primary advantages are: They do a better job than hand washing in a fraction of the time. They wash, rinse and sanitize automatically with consistent, repeatable results. Plus, they can be equipped with data loggers to record wash temperatures, rinse temperatures, cycle times and operating pressures.”
According to Lemen, some automated washers can handle one or more of a combination of vats and bins. Normally, the only required adjustment is taking a standard machine and modifying the product support guides on the doors to match a specific container. Sometimes, an oversized container requires a custom design as well.
In a pipeline and enclosed vessels, the temperatures, chemical concentration and contact time can be increased for more effective cleaning and sanitation, without affecting operator safety, says Miller. External cleaning is generally limited to approximately 140°F for safety and practical reasons. In a contained CIP recirculation system, temperatures of 180°F to 200°F can be achieved if necessary, with higher chemical concentrations and for whatever time is necessary for effective cleaning. (External surfaces, such as conveyor belting, require higher pressure for direct impact as well as foaming detergents for longer contact time.)
Adequate spray coverage is achieved without manual operations through the use of spray nozzles. There are primarily two types of nozzles: fixed (for conveyors and other rotating equipment) and rotational (often used in static tanks and vessels). Each has its advantages and disadvantages, depending on the application. Most spray nozzle manufacturers make both types.
Birko’s Owens says processors are moving from fixed or static spraying systems to dynamic spraying systems where the force of the solution being pumped through the spray ball or spray head causes it to spin or oscillate, adding increased mechanical action to the CIP process. As long as the spray balls are compatible with the cleaning solution, and the cleaner concentration is appropriate, there is no reason not to expect them to have a long, effective service life.
“New CIP nozzle designs are providing better coverage, impact and use of cleaning media due to controlled rotation designs that allow the nozzle to make the best use of the flow rates and supply pressures available,” says Noah Wallace, BETE Fog Nozzle Inc. applications engineering supervisor. “In many basic stationary and reaction force-driven rotating spray ball designs, the washing efficiency of the nozzles can decrease as supply pressure increases. This causes an increase in rotational speed [in rotating designs] and atomization of the cleaning media that can result in less throw and impact from the nozzle.” Controlling the pattern and rotation of the nozzles (through bearing design, fluid-driven turbines, mechanical motors, etc.) enables them to produce a more effective, concentrated spray pattern, resulting in a more efficient use of the cleaning media. Controlling the rotation and pattern also allows CIP nozzles to operate at higher pressures and provide greater coverage and impact with a given flow rate, according to Wallace.
“The vast majority of tank CIP applications involve cleaning with fixed spray balls, for several reasons,” says Sani-Matic’s Miller. First, fixed spray balls have no moving parts that can break loose or shed particulates in product contact areas.
Second, fixed spray balls can be sized to match the flow rate necessary for both the vessel and attached pipelines. Although a rotary spray device may operate at a lower flow rate, it must be located high enough to clean the associated infeed and discharge pipelines. Therefore, if a tank can be cleaned at 50 gpm but has a discharge pipe that requires 100 gpm, the lower flow rate serves no purpose, and may cause other, unintended cleaning problems.
Third, if a rotary spray device does not rotate, it is totally ineffective, and the rotation is difficult to measure. On the other hand, if a fixed spray device gets partially plugged, the plant can know immediately about the problem by monitoring the flow rate.
Fourth, plants also must be aware of the required orientation of spray devices, since some must be mounted vertically to rotate properly and avoid premature wear. Finally, rotary spray devices require a good preventive maintenance program that includes inspection, teardown and rebuilds on a scheduled basis.
While Miller may not seem to be a fan of rotary spray devices, he argues there are many reasons to use them. But processors must review their applications and test the devices to verify their proper performance and the lowest cost of operation. Possible applications for rotary devices include:
1. Long, over-the-road tankers
2. Vessels with many varying surfaces or difficult soils, such as food dryers or processed cheese blenders
3. Extremely difficult soils that are not soluble in caustic
4. Tote and small tank washing.
While the service life of spraying equipment in CIP applications depends on many factors including the style of the nozzle, the environment and the operating conditions, it can be maximized by using the equipment within the manufacturer’s suggested operating ranges, says BETE’s Wallace. Utilizing compatible spray media and the appropriate filtration of spray media, staying within the maximum recommended ambient and operating temperatures, operating at appropriate pressures for effective nozzle operation (maximizing washing efficiency/minimizing operating costs/reducing impact on wear parts) and even ensuring a slow startup (avoiding water-hammer) can all lead to an increase in nozzle service life and help operators get the most out of their CIP spray units.
Many basic stationary and rotating spray balls that have lower initial capital costs are constructed as “expendable” units, since their design does not allow for the refurbishment or replacement of wear parts. Other styles, including some controlled rotation spray balls and rotating jet machines, generally have higher initial capital costs. But, to help extend their service life, they are often designed with specific wear parts that can be replaced for less than it would cost to purchase a new unit, according to Wallace.
For more information:
Henry Dao, HSP USA, 856-437-0688, email@example.com
Gabe Miller, Sani-Matic, 608-226-8573, firstname.lastname@example.org
Ellis M. Owens, Birko, 800-525-0476, email@example.com
Noah Wallace, BETE Fog Nozzle, Inc., 413-772-2166, ext. 129, firstname.lastname@example.org
Kevin Lemen, Douglas Machines Corp., 800-331-6870, ext. 210, email@example.com
Jeff Sporer, SPX Flow Technology, 262-728-4610, firstname.lastname@example.org