At the heart of all spray operations in your mill, is the spray nozzle. It is the component that determines performance in moisturizing, cleaning, lubricating, edge trimming, bleaching, knock-off, gluing and dozens of other applications . Worn nozzles can raise water consumption drastically.

The cost of using nozzles worn by only 15% in your mill can increase by thousands of Rands.

At Spraying Systems Co we have developed 6 strategies to help you save water, chemicals and energy in your mill.

Flow

Centrifugal pumps: Monitor the readings of your flow meter to check for increases in flow.
Use a calibration vessel to measure the flow of a nozzle for a specific time at a specific pressure.
Compare the readings with the manufacturers catalogue or compare them with the same tests conducted on a new nozzle.

Positive displacement pumps: In applications using positive displacement pumps, which provide the same capacity regardless of pressure, the spraying pressure will decrease as the nozzle orifice enlarges. Lower spray velocities and spray impact will result.

Pressure at showers and nozzles

Centrifugal pumps: Monitor for increases in volumes of liquid sprayed. The pressure of the spray could decrease.

Positive displacement pumps: Monitor gauges to detect any drop in pressure and reduction on the impact on surfaces sprayed. The volume of the sprayed liquid may remain the same. Also monitor for any increases in pressure which could be caused by blocked nozzles.

Drop sizes

As nozzle orifices wear, the liquid flow increases or the spraying pressure drops, resulting in larger drop sizes. Larger drops result in less total liquid surface area.
Actual drop size

Impact

Check for premature wear of the felt or any other related problems. In applications with centrifugal-type pumps, impact may actually increase because of the increased flow through the nozzle.

Spray Pattern

Visually inspect the spray pattern to detect any changes in uniformity.
Streaks and heavier flows in the centre of the pattern, accompanied by a decrease in the effective spray angle coverage typify deterioration.
Measure the width of the spray over the surface sprayed.
If the nozzle wears gradually, you may not be able to detect any changes until a significant increase of flow is evident.

Spray patterns of both tips show little difference. Spray collection in tubes gives dramatic evidence of 15% increase in capacity.

Contact us for complementary paper machine and nozzle audits in your plant and for a copy of our new paper catalogue.

WindJet Air Knives powered by energy-efficient regenerative blowers provide excellent performance in drying and blow-off operations and eliminate the need for costly compressed air. Operating costs can be reduced by as much as 95 percent when the packages are used in a wide range of operations including debris and dust blow-off, removal of excess water and moving products.

WindJet Air Knives feature a unique 1/8″ leading edge along the length of the knife to direct a consistent and controlled air stream that retains its integrity further downstream and eliminates spotting and blotching. The air stream produced by the knives entrains ambient air to increase the total volume of air and maximize drying and blow-off efficiency.

Unlike other blower types, the regenerative blowers included with the packages are rugged, reliable and require infrequent, minimal maintenance. Plus, no sound enclosure is needed because the blowers provide low noise operation. Each air knife package is customized for the application. Air knives are available in lengths from 6” to 36” and two air slot sizes, .040” and .060”. Regenerative blower assemblies are available from 5.5 to 30 HP. Packages include pressure relief valve, pressure gauge, air inlet filter, filter monitoring gauge, vibration dampener, fittings and mounting adapter.

Spraying Systems Co. is the global leader in spray technology. Spray nozzles, turnkey spray systems, custom fabrication and research/testing services comprise the company’s offering. Spraying Systems Co. has ten manufacturing centers and more than 90 sales offices around the world. More information is available from your local office.