Disposers/Pulpers & Compactors

By Staff -- Foodservice Equipment & Supplies, 9/1/2006

Types: Disposers with rotor-fixed cutting teeth are the most common varieties, although some may be equipped with swivel cutting teeth or a hammer-mill-type grinder. In all instances, a cutter rotates at a high speed inside a stationary shredder ring. As centrifugal force moves foods through a shredder, waste washes into the lower area of a unit and down a drain or into a compactor.

Waste compactors are available in a variety of styles. A new type of pulper is an organic-waste disposal system. The completely self-contained system decomposes food waste into liquid by applying heat, water and motion to organic waste held in a central drum. Disposal of the resulting liquid occurs through existing sewage treatment facilities. The liquid’s nutrient-rich nature allows operators to add it as a supplement to irrigation and plant-watering systems. Such a system practically eliminates on-site food waste, reducing the risks posed by cross-contamination, pests and other health threats.

Capacities/Footprints: Disposer motors range from 1⁄2 hp up to 10 hp. Smaller horsepower units can attach to sinks with no support necessary. More powerful disposers require a leg that reaches the floor for support. Horsepower determines shredding capability, as well as their capacity for continuous operation. Light-duty disposers are intended for use in delis and convenience stores. Heavy-duty, small-, medium- and large-capacity disposers are designed to meet the needs of larger operations. The body size of a disposer determines its waste-handling capacity. Compactors are used in conjunction with disposers. Compactors are available in 1, 2, 3 and 5 hp, disposing from 300 to 900 lbs. of waste per hour.

Energy Source(s): Disposers and compactors are available in the following voltages; 115, 208, 230, 208, 230 and 460 volts.

Standard Features - Disposers: A standard electrical wall switch can operate light-duty disposers. Larger disposers have a variety of electronic controls from which end-users can choose. The most common electronic control is a manual reverse switch that allows shredding in both directions. This feature can help unjam a stuck unit and extend the life of a disposer. Automatic reversing controls for disposers start a unit in the opposite direction upon activation.

Designed with the correctional market in mind, some disposers sit several inches offset from a sink drain to prevent tampering. Similarly, operators can equip most units with tamper-proof screws.

Disposer accessories include an unjamming wrench, which staff can insert into a jammed machine and twist to dislodge stuck objects. Other accessories are magnets that prevent flatware and other metallic objects from falling into a unit. In the safety realm, operators can purchase many disposers with guards that prevent individuals from reaching into an operating unit.

Standard Features - Compactors: All compactors include a standard manual switch control panel. Many manufacturers offer water controls with disposers and compactors to regulate the amount of water going in and out of units. These controls help minimize water and drainage costs and can help pay for a disposer in a matter of several months. A siphon breaker prevents backflow, while a solenoid valve ensures that water runs straight through a disposer. Flow control valves provide the correct amount of water for each sized model.

To ensure longer use-life, a controlled airflow encloses and cools motors. Triple-lip seals also protect most motors from water damage. A secondary spring-loaded oil seal available on many models provides extra security against water damage and loss of grease. Disposer housings are available in a variety of durable, corrosion-resistant materials ranging from hardened aluminum to stainless steel. Some disposers are coated or plated.

Compactors are constructed of stainless steel and are designed to produce an 85-percent reduction of waste volume. A 5-hp compactor features a 1⁄2-hp recirculation pump to reduce water consumption. Five-hp compactors usually consume 1 gal. per minute. One-, 2- and 3-hp compactors consume 3 gals. per minute.

Standard Features – Pulpers: A mechanical seal prevents liquid from leaking into the drive motor. A stainless-steel ring controls the size of the solids entering the slurry chamber. A throat guard mounts directly between the disposer and sink bowl to keep hands or other large objects from entering the disposer grind chamber. Some municipalities require this accessory to satisfy their safety regulations. Also useful when limited space requires the disposer to be mounted off-center from a sink opening. One maker offers a dejamming wrench that helps with simple backups.

New Features/Technology/Options: While pulpers traditionally require a mix of organic and non-organic waste to operate properly, some manufacturers offer units that can work when used almost exclusively for one or the other.

Key Kitchen Applications: Commercial disposers are most commonly found in food prep and warewashing areas. They are designed to provide maximum shredding for the disposal of food and non-food waste. Pulpers and compactors compress food waste, thereby minimizing the volume of such waste in a kitchen, resulting in fewer pests. They can also reduce volume-based trash removal fees. Some pulpers process both liquid and solid waste, which reduces the amount of time kitchen staff spend separating trash and making trips to the dumpster. Designed for continuous operation in locations such as restaurants, nursing homes or assisted-living facilities, some pulpers can process up to 700 lbs. of waste per hour.

Purchasing Guidelines: A disposer/pulper/compactor system can result in significant savings in water use, sewage costs and waste removal charges. By immediately removing food waste from the BOH area, they also help eliminate pests and reduce the labor needed to haul trash.

Maintenance Requirements: By design, disposers are very low-maintenance equipment. After shredding, waste water must simply be run through a unit to eliminate clogging.

Compactors are also intended to be low-maintenance and easy to clean. No tools are required to clean a compactor. Staff should simply take apart and clean the pulper screen once a day.

Food Safety & Sanitation Essentials: Disposers and compactors allow for speedy elimination of waste, assisting in insect and rodent control.