At Your Disposal
Trained staff and units properly matched to operations can keep disposing of food wastes from becoming a grind.

By Harry Stern, Special to R&I

There is no getting around it: Foodservice operations produce food waste. And yet food-waste disposers often are relegated to the bottom of the equipment list or even dropped because of budgetary squeezes.

When considering whether to buy a disposal unit, an operator might only consider the fact that it produces no income. Looking at the other side of the coin, however, one sees that disposal units are cost-effective, convenient, sanitary and environmentally friendly.

Appropriately sized disposal units can be located where needed, be it at the scrapping (soiled dish) table, vegetable prep or pot sink area. In addition, research shows that disposers are the most ecologically sound method of eliminating biodegradable food waste.

The alternative? Bagging and carrying the food waste, which adds to labor costs. Couple that with the expense of hauling; the mess and smell that bagged waste left in containers, at the curb or in alleys, produces; and the rodents and other vermin that might be attracted to such a feast. Being “indisposed” clearly is a costly position.

SHREDDERS AND GRINDERS

There are two basic types of disposal units. The rotor-style type with fixed teeth is by far the most common. Its cutter rotates at high speed inside a stationary shredder ring; centrifugal force sends the food to the shredder, which shears pieces until they are small enough to be washed into the lower section of the unit and from there down the drain. Fresh water is injected into the unit at a rate sufficient to keep the drain from clogging.

Attached to the rotor—also called the turntable, grinding table, flywheel or grind wheel—are from two to six cutter blocks or impact breakers. These force food against the shredder ring (also called a grinding sleeve).

Hammermill-type units employ several swinging cutter arms (eight to 16 depending on the unit’s size) that force food against a grind screen.

TROUBLESHOOTING

Disposal units must be used with care; proper training can go a long way toward avoiding problems. Certain food items (celery peelings or fibrous material such as cornhusks or artichoke leaves), oyster or clam shells, or nonfood items (flatware and other metals, paper, plastic, rags or other foreign objects) can jam or clog units. The obvious solution is to make sure no foreign objects are put through the units. In addition, flowing water is critical to keeping lines properly flushed; most manufacturers recommend pre- and post-flushing when disposing of food waste.

Many units have an automatic post-grinding feature which times water flushes up to several minutes. Rotor-style disposers often feature an automatic reversing control which helps alleviate jams by starting the rotor in the opposite direction.

Preventive maintenance, such as periodic drain cleaning during downtime, can reduce or eliminate emergencies during peak business periods. Jams tend to be less frequent in institutional operations, where staff training and low turnover help ensure that the equipment is respected and properly used. At chain restaurant operations, where employee turnover is greater, training and supervision are more critical.

SIZING UP THE SITUATION

When buying a disposal unit, it is important to determine the size best suited to an operation. Factor in type and volume of food waste to be disposed of and where in the kitchen disposers will be needed. Other important variables include motor size (measured in horsepower), cutter/rotor diameter and drain size.

Manufacturer sizing charts can help answer these questions. For example, a 1,000 meal-per-day operation usually requires a 5-horsepower unit for the soiled- dish area, plus a 11/2-horsepower model by the pot sink. The menu is another important consideration. A barbecued-rib operation, for instance, would require a disposer with enough horsepower to handle the volume of bones in its waste.

When evaluating equipment needs, remember that it always is better to oversize than oversize.

Editor’s note: All information was provided by manufacturers to Harry Stern, president of Stern Associates Ltd., a food-equipment consultancy.