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By automating a cleaning system and placing manifolds above and below conveyors, most processors report a 50-60% drop in water and chemical use.
Jon Barber of Spraying Systems Co. in Wheaton, IL, says that the sluggish economy often causes manufacturers to convert their “cost management” programs into “cost reduction” programs.
But Barber warns that cutting costs can have a negative impact on products and process quality, and can actually lead to higher scrap rates, costlier product recalls and unhappy customers. Instead, Barber has another idea to save money for those who spray on a finish: Change the way you spray.
“In many operations, opportunities exist to reduce operating costs without compromising quality,” he says. “Some new equipment may be required, but the resulting cost savings will offset the purchase price quickly.”
Barber, whose company is its 70th year and has 12 manufacturing plants around the world, suggests seven changes that can have a significant impact on a coater’s bottom line. The suggestion won’t all apply to every spray operation, but many lower operating costs in cooling, coating, cleaning, sanitizing, lubricating and moisturizing applications.
Eliminate the use of open hoses for clean-up and sanitation. Use hoses with spray guns instead.
Barber: You can reduce water consumption by as much as 50% by using low-pressure spray guns instead of open hoses. Ensuring that water is “on” only when needed can cut water use in half. It’s a small change that can yield big savings. For example, a food processor was using 15 open hoses for sanitation, eight hours per day, five days per week, 50 weeks per year. 500,000 gallons of water were used daily. Using hoses equipped with spray guns, water use decreased by 30% per hose, or 17,280 gallons per day. They saved $30,240 annually on water and disposal costs. The cost of the spray guns was recouped after approximately 30 days of use.
Check your nozzles regularly. If they are spraying more than 10% over the rated capacity, replace them.
Barber: Using nozzles that are spraying just 15% over the rated capacity could be adding as much as $200,000 per year to your operating costs. A quick look at your nozzles will only reveal obvious problems such as clogging, corrosion or damage. Wear of the nozzle orifice isn’t visible but it can be very costly. Here’s an example: nozzles spraying 15% over capacity; total system flow of 100 gpm. The cost of increased electricity or pump wear is not included in this example. Water is estimated at $2.75 per gallon; chemicals at $1.00 per gallon with a 10:1 dilution ratio, and the system is in operation 2,080 hours per year. This is a conservative estimate and is based on one spray system. Most plants have many spraying operations, so $182,800 in waste could easily become $500,000 or $1,000,000 if multiple systems are in use. You can prevent this waste from occurring. Measuring flow rate is a quick and easy process and well worth the small effort required.
If you are using centrifugal pumps, monitor flow meter readings to detect increases. Or, collect and measure the spray from the nozzle for a given period of time at a specific pressure. Then, compare these readings with the flow rates in the manufacturer’s catalog. If you are using positive displacement pumps, monitor the liquid line pressure for decreases. The flow rate will remain consistent.
Automate conveyor cleaning.
Barber: Installing spray manifolds above and below conveyors can save hours of labor and thousands of gallons of water and cleaning chemicals. Automating conveyor cleaning also enables workers to be deployed to other projects.
Manifolds are typically equipped with flat spray nozzles to cut through debris and sticky buildup. Nozzles are positioned to ensure cleaning of the entire belt width and edges. Full cone nozzles with extra large free passage are often used to minimize clogging when re-circulated water is used for cleaning. A basic spray controller can be used for precise on/off control, activate cleaning cycles based on predetermined schedules and ensure nozzles are only spraying when needed.
The specifics of your application will determine how much you can save by automating conveyor cleaning, but most processors report water and chemical reductions in the 50–60% range.
Add headers/manifolds to reduce maintenance time and ensure long nozzle life.
Barber: If you’ve ever struggled with connecting air and liquid lines, or been faced with a tangled mess of tubes, you will immediately understand the value manifolds can bring to your operation. Set-up and maintenance time can go from hours to minutes and result in increases in production time. Downtime due to performance problems caused by bends or kinks in the tubing is eliminated and the added protection of the manifold keeps nozzles operating at peak efficiency longer.
Add spray control.
Barber: Adding spray control usually yields: 1) Reduced use of costly chemicals, water and energy; 2) Reduced manual operation and monitoring, freeing workers for other tasks; 3) Reduced maintenance time by minimizing or eliminating overspray and misting; 4) Reduced scrap through improvements in quality; 5) Reduced downtime for set-up and batch changes.
There are many spray control options available:
• Fluid delivery systems that include standard pump and motor sets can optimize the performance of a wide range of nozzles including tank cleaning nozzles.
• Basic spray controllers provide precise on/off liquid and air control for automatic spray nozzles.
• More sophisticated controllers provide advanced timing control to optimize the performance of automatic spray nozzles, electronically monitor pre-set spray variables in real-time and offer advanced fault monitoring to alert operators to problems. Some can be pre-programmed to monitor and automatically adjust spray performance based on process variables such as conveyor speed, temperature and batch control.
• Fully automated systems are available for advanced spray operations such as gas cooling, lubrication, panel board spraying, antimicrobial application, coating with viscous fluids and more.
Reductions in operating costs will obviously depend on your spray application and the level of spray control selected. Often, the cost of adding spray control or a fully automated system can be recouped in just a few months.
Replace open pipe with air nozzles or air knife packages for drying or blow-off.
Barber: If you’re using pipe with drilled holes or slits for drying or blow-off, you’re wasting costly compressed air. Installing air nozzles will reduce your air consumption up to 36%. Changing to air knives powered by regenerative blowers will eliminate the need for compressed air entirely. Both of these alternatives will not only lower your operating costs, you may find products are dried more thoroughly or moved more accurately.
In many operations, recouping the cost of air nozzle manifolds takes just a few weeks. Recouping the cost of an air knife package with blower will take a little longer, but you can still count on a quick payback and significant annual savings.
Automate cleaning of tanks, totes, vats and vessels.
Barber: If tank cleaning in your facility involves filling and draining or manual cleaning, there’s an unnecessary profit leak in your plant. There are dozens of ways to automate cleaning of tanks of all sizes, and all of them will significantly reduce: cleaning time; manual labor; water, chemical and energy use; and wastewater disposal costs.
Tanks will be cleaner and returned to service more quickly enabling increases in production time. Savings of $50,000 per tank aren’t uncommon. Most plants have multiple tanks, so it is easy to see how automating cleaning of multiple tanks can save hundreds of thousands of dollars per year by reducing operating costs and increasing production time. Selecting the right automated tank cleaning product primarily depends on tank size, the level of impact required to remove the residue in the tank, the chemicals used for cleaning and the temperature of the cleaning liquid.
Options include spray balls, stationary tank cleaning nozzles, high-impact fluid-driven units, motorized tank cleaners and fully automated tank cleaning systems. Ask your tank cleaning equipment supplier for a no-obligation on-site evaluation to determine which solution is best for your application and to provide a pay-back analysis. The evaluation is usually free and is an efficient way to get the automation process started.