ACHRNEWS

Operating trouble-free ice machines

August 14, 2000
Q: What’s the single most important cause of equipment failure in ice machines?

A: The water.

In its purest form, water is H2O — two parts hydrogen and one part oxygen. Water is also known as the universal solvent, in that it will dissolve bits of everything it comes into contact with.

As water forms clouds in the atmosphere, it absorbs impurities in the air: dust, gases, smog, and pollution. And as the water condenses and falls to earth as rain, hail, sleet, or snow, the process of absorbing contaminates continues.

Once on the ground, water contacts and dissolves additional substances. For example, surface waters like lakes, rivers, and streams become murky from soils. Ground waters like wells and aquifers dissolve and contain “hardness” minerals. Other substances found in water include bacteria, fertilizers, and insecticides.

All water supplies will have varying characteristics, and the source of the water will affect those characteristics. Ground waters will generally contain higher levels of hardness minerals, while surface waters from rivers and reservoirs will contain lower mineral concentrations.

Regardless of the source of the water, the potential for water-related problems in icemakers abounds. They can include scale formation, objectionable tastes and odors, sediment, and slime growths.

Proper water treatment will eliminate water-related problems. Knowing your water and taking preventive steps will help ensure trouble-free ice production for your customer.

Scale control

Scale is a common problem in ice machines. Even though the water is not heated, hardness minerals tend to concentrate in the unfrozen water and precipitate out on the freezing surfaces, restricting tubes, orifices, and valves.

Ice in a scaled machine tends to stick to the scale, jamming the machine and stopping production. Scaling conditions in a commercial ice machine result in higher energy costs, lower ice production, and costly breakdowns.

Years of experience with ice-making equipment have proven that the best way to solve this problem and reduce service calls is to prevent this scale formation by treating the water with specialized, slowly soluble, food-grade polyphosphates.

Specialized polyphosphates keep scale-forming minerals in solution so that they can be removed via the dump or bleed cycle, thus preventing formation of scale on the freezing surfaces of ice machines. Proper application of polyphosphate scale inhibitors offers an effective and reliable method of preventing scale-related problems in ice machines.

Taste and odor control

The taste and odor of water has a major impact on its quality, and ultimately on the quality of the ice produced. The taste and odor of ice can be affected by a variety of factors, the most common of which is chlorine.

Municipalities routinely chlorinate water supplies to protect us from waterborne algae and bacteria. Chlorine is very effective at killing harmful bacteria, but it is frequently the source of undesired tastes and odors.

Other sources of tastes and odors include earthy, woody, or fishy smells; gasoline or hydrocarbons; synthetic organic chemicals (including pesticides and herbicides); and volatile organic compounds like hydrogen sulfide (“rotten egg” odor).

The most common and effective treatment to prevent taste and odor problems in ice production is the use of activated carbons. Types of activated carbons used in ice machine filtration include powdered, granular, and carbon block technologies.

Activated carbon media has an extensive surface area and it removes tastes and odors from water through the process of absorption, in which the objectionable matter adheres to the surfaces of the activated carbon.

All activated carbons have a surface whose texture is much like a sponge. The carbon works by absorbing the undesired chemicals in the water. Studies indicate that all of the forms of activated carbons reduce most or all of the chlorine, but vary in their ability to reduce various organic compounds.

Sediment and slime

Sediment removal is simply the filtration of tiny suspended particles that are not dissolved in the water. These particles add poor taste, clog pumps, enhance lime scale buildup — and can be effectively removed with filtration.

Frequently referred to as “prefiltration,” sediment filters remove particles as small as 0.5 micron from the water supply.

Prior to the installation of a filtration system, the machine should be cleaned with a commercial ice machine cleaner or nickel-safe ice machine cleaner to remove existing scale deposits, then sanitized with an EPA-registered sanitizer. A clean, sanitized machine will provide the optimum results from filtration systems.

Frequently ice machines are troubled by slime and bacteria growth within the machine and the ice. Sources of the bacteria include the water, the air, and the user.

It is imperative that the ice — an edible product — be protected against contamination by bacteria.

Proper treatment will depend upon the source of the bacteria. Treatment options range from chemical sanitizers to submicron filtration to ultraviolet lights to ozone generators. At a minimum, periodic and scheduled sanitation should be incorporated.

In the case of ice machines, truly “An ounce of prevention is worth a pound of cure.” Proper filtration is the key to operating trouble-free ice machines.

Sidebar: New machine for small ice demand

DENVER — Ice-O-Matic announced the addition of the EUC-150 to its EUC product line.

This new-capacity, self-contained, under-counter machine produces up to 175 lb of ice and features a storage capacity of 100 lb, according to the company.

Available in air- or water-cooled models, the EUC-150 incorporates the use of R-404A (an HFC refrigerant) to provide efficient ice production without harmful CFCs.

With a small footprint (24 by 24 by 39 in.), the company says the machine has also been designed to be easy to clean and service.

For more information, contact your Ice-O-Matic representative or call 303-371-3737.