Disposers/Pulpers & Compactors

Types: Disposers with rotor-fixed cutting teeth represent the most common type of unit, although some may feature 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.


The main types of pulping systems are close-coupled and remote. Close-coupled systems are freestanding and include a pulper connected to an extractor. This setup helps decrease waste volume in operations that do not allow centralized food waste collection. Remote pulpers are connected to extractors by piping and wiring.

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 can significantly reduce on-site food waste, lowering the risks posed by cross-contamination, pests and other health threats.

Waste compactors are available in a variety of styles. Compactors with built-in carts offer easy portability and accommodate up to 750 gals. of loose trash. Portable and mobile compactors have wheels or casters and can contain between 300 and 1,000 gals. of waste. Automatic or public area compactors are designed for dining room use and can hold up to 300 gals. of trash.

Capacities/Footprints: Disposer motors range from 1⁄2 hp for smaller kitchens and light volume up to 10 hp for institutional and banquet operations. Smaller horsepower units can attach to sinks with no support necessary. More powerful disposers require a leg that reaches the floor for support. Although all disposers handle the same type of waste, 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. Foodservice operators should use compactors in conjunction with disposers. Compactors come in 1-, 2-, 3- and 5-hp models, disposing from 300 to 900 lbs. of waste per hour.

Energy Source(s): Depending on the facility's needs, foodservice operators can choose from disposers and compactors in the following voltages: 115V, 208V, 230V, 208V, 230V and 460V. Single- and triple-phase models are also available.

Standard Features - Disposers: Disposers are available in a number of configurations and offer a choice of mounting systems and accessories. Unit housing is typically constructed of aluminum, stainless-steel or cast-iron. Some models are coated or plated. Most cutting mechanisms are made of rust-resistant nickel or stainless steel.

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, helping to extend the cutting mechanisms' service life.

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 machine and twist to dislodge stuck objects. Magnets on some units prevent flatware and other metallic objects from falling into a 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 the 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.

Compactors feature stainless-steel construction and their design can 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.

New Features/Technology/Options: One newer disposer feature senses when the unit is turned off and automatically stops the water from flushing. Some models offer control panels that automatically turn the disposer off after a period of non-use, conserving water and energy.

While pulpers traditionally require a mix of organic and non-organic waste to operate properly, some manufacturers offer units that can work almost exclusively for one or the other. Another feature is a built-in silverware trap that keeps cutlery from being disposed.

At least one compactor model, geared for front-of-thehouse use, provides a built-in motion sensor. This unit automatically opens the waste deposit door for hands-free use, and has a talking feature that invites patrons to deposit their waste.

Key Kitchen Applications: Commercial disposers are most commonly found in food prep and warewashing areas. They 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 volumebased 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.

Purchasing Guidelines: A disposer/pulper/compactor system can result in significant savings in water use, sewage costs and waste removal charges. Determining the type and volume of waste the disposer can accommodate will help gauge the amount of horsepower that is needed. Additionally, because there are sink, cone and trough mounting configurations for these units, operators should confirm that the unit type is appropriate for their needs.

Maintenance Requirements: By design, disposers are very low-maintenance equipment. After shredding, waste water must simply be run through a unit for approximately three minutes to eliminate clogging and flush food waste from drain lines. Compactors are also intended to be low-maintenance and easy to clean. Staff should simply take apart and clean the pulper screen once a day.

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