Browse Our Archives

September 2007

Make Better Snow for Less Money

If the nozzles on your snowguns are damaged or degraded, they are just spitting away your profits.

Written by Daniel Vidusek, Director, Spraying Systems Co. | 0 comment

One of the most critical components in your snowmaking system is the spray nozzle. Yet spray nozzles often receive attention only when they no longer work at all. Regular maintenance will save time, money and water—and give your customers a better experience.

Like any precision component, spray nozzles wear over time. Most nozzles will last about two years before wear becomes a big enough problem to warrant replacement. However, total hours of use and operating conditions determine actual life. In general, you should inspect nozzles before the first use each season and replace damaged or eroded nozzles.

There are several things you can do to extend the operating life of your nozzles. But first, let’s look at the potential performance problems and costs associated with nozzle wear.


Nozzle Wear Basics
Even though water is exiting the nozzle orifice, you may not be producing high quality snow at the lowest possible cost. Spray nozzles that are worn typically produce snow with too much moisture, which translates to less than ideal snow on the slopes. In addition, worn nozzles use more water and increase your utility costs. So, what can you do to avoid these expenses?

Nozzle performance can be compromised or rendered ineffective by eroded, damaged or obstructed nozzle orifices. The top causes of nozzle wear are:

• erosion. Gradual removal of the nozzle material causes the nozzle orifice and internal flow passages to enlarge and/or become distorted. Water, and material in it, can all cause erosion. As a result, flow is increased, pressure may be decreased, the spray pattern becomes irregular and the spray drops become larger. The larger water droplets won’t freeze—and you’ll get wet, heavy slush.

• poor quality water. Many areas use river or pond water, recycled water, or runoff collected from down-slope holding ponds. All of these sources contain particulates and debris that will accelerate the wear of the nozzle orifice. Water, in general, causes steel pipes to rust, and rust also causes wear.

• accidental damage. Improper cleaning tools can damage the nozzle orifice by inadvertently denting them. Nozzles can also be damaged if they are dropped during installation.


Detecting Spray Nozzle Wear
Detecting nozzle wear can be challenging. The most obvious signs are poor quality snow and poor snow distribution. If you see these conditions, inspect your nozzles to determine whether they are clogged, worn or damaged, and take the appropriate action.

But gradual nozzle wear is very difficult to detect visually. Specialized testing in a laboratory environment is required. Spray patternators, laser drop size analyzers, wind tunnel and other instruments are commonly used to evaluate spray distribution, coverage, spray angle, drop size and more.

The solution? Ask a nozzle manufacturer to test your nozzles and provide maintenance and replacement recommendations at no charge. Make sure the manufacturer has the necessary testing equipment and experience working with snowmaking nozzles to ensure the best results. Typically you will ship nozzles from various snowmaking machines to the nozzle manufacturer, indicate the placement of the nozzle on the machine, and provide the number of hours the nozzle has been in use.

This information will allow the manufacturer to determine the wear rate and provide recommendations for appropriate replacement intervals. The nozzle manufacturer may also recommend the use of strainers and/or a change in nozzle material if wear is unusually high.


Extending Nozzle Life
While nozzle wear is inevitable, you can slow it down and extend the service life of your nozzles.

1. Use strainers with your nozzles. You’re not going to change your water source, so you should take steps to minimize the damage it causes. Adding strainers can prevent debris from reaching nozzle orifices and help slow erosion and wear. Choose strainers with a screen mesh size that will trap larger particles and prevent debris from entering the nozzle orifice. Most new fan guns have single or dual water filters as standard; some tower guns may have water strainers on inlets to the tower tube.

Strainers will also help reduce clogging. When solid particles block the nozzle orifice, flow is restricted and the spray pattern is disturbed. To minimize clogging you must reduce the quantity of abrasive particles reaching your nozzles. You should also conduct maintenance regularly to remove debris.

If you are using strainers and are cleaning your nozzles on a regular basis but are still plagued with frequent clogging, a different-sized strainer may alleviate the problem. Do not change nozzle type without consulting the manufacturer of the snowmaking machine.

2. Improve cleaning procedures. Carefully maintain your nozzles. Clean nozzle orifices with cleaning probes made of materials much softer than the nozzle orifice surface, such as plastic bristle brushes and/or wooden and plastic probes. Wire brushes, pocketknives or welders’ tip cleaning rasps can easily and seriously damage the nozzles.

3. Use nozzles constructed of wear-resistant materials. Side-by-side wear testing shows that ceramic orifice nozzles can be used up to 15 times longer than conventional nozzles before wear occurs. Most conventional snowmaking nozzles can be used for perhaps two years before replacement is necessary, depending on water quality. A change to nozzles with ceramic orifices can vastly extend service life—up to 30 years.

The cost savings associated with the use of ceramic nozzles can be significant. In addition to purchasing nozzles less frequently, maintenance and replacement times are greatly reduced, further cutting costs. The total cost of ceramic nozzles over 15 years can be 75 to 80 percent less.

4. Watch for caking. Usually in the form of ice build-up inside or on the outer edges of the nozzle orifice, caking can obstruct the orifice or internal flow passages. Most snowmaking nozzles are designed to prevent this, but if you’re having trouble, consult the manufacturer of the equipment.

With a little effort, you can ensure optimal performance of your spray nozzles. Evaluate your nozzles to confirm you are using the best nozzles available for your operating conditions. Conduct regular inspections and maintenance. And enlist professional help for testing nozzle wear and developing a regular replacement schedule. These steps will help ensure you produce the kind of snow your patrons expect, at an operating cost you can accept.


Daniel Vidusek can be reached at Spraying Systems Co., 630-665-5000, dan.vidusek@spray.com.