Disposers, Compactors and Pulpers

Types: Disposers are categorized by horsepower. The smaller horsepower units are geared to lighter volume and easily ground food waste, while larger volume applications and food waste that is harder to grind up are best served by high horsepower disposers.

Disposers with rotor-fixed cutting teeth are the most common varieties, although some may be equipped with swivel cutting teeth or a hammermill grinder. In all instances, a cutter rotates at a high speed inside a stationary shredder ring.

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

Scrapping systems are designed to provide a complete scrapping station that will pre-rinse and handle food waste in one footprint. These systems recirculate water, and can greatly reduce the amount of fresh water required for the scrapping process, while providing a much higher volume of water available for scrapping to speed up the process and reduce labor.

The main types of pulping systems are close coupled and remote. Close-coupled systems are free-standing 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. These pulpers and extractors may be located from a few feet to several yards away.

A newer 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.

Capacities/Footprints: Disposers are available in ¾-,1-, 1½-, 2-, 3-, 5-, 7½- and 10-horsepower models. Disposers purchased with a sink assembly are mounted to the bottom of a sink, only taking up space under the table. Disposers purchased with a cone assembly come with a 12-, 15- or 18-inch stainless steel cone bowl that is welded into a table.

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.

Compactors are used in conjunction with disposers. Compactors are available in 1-, 2-, 3- and 5-horsepower, disposing from 300 to 900 pounds of waste per hour.

Scrapping systems come with a perforated basket or a 3-, 5- or 71/2-horsepower size disposer. Each unit will have either a sink basin that is approximately 20˝ x 20˝ or 22˝ x 29˝ or a trough up to 12 inches wide and 18 feet long.

Energy Source(s): Disposers and compactors are available in the following voltages; 115, 208, 230, 208, 230 and 460, with single and triple phase models available. Pulpers are available in three-phase, 208, 230 or 460 volts.

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, stainless steel or austempered heavy ductile iron.

A standard electrical wall switch can operate light-duty disposers. Larger disposers have a variety of electronic controls from which 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 on activation, helping to extend the cutting mechanism's 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 jammed machine and twist to dislodge stuck objects. Magnets on some units prevent flatware and other metallic objects from falling into a unit. In terms of safety, operators can purchase many disposers with guards that prevent individuals from reaching into an operating unit.

To ensure longer use, 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.

Standard Features — Compactors: All compactors include a standard manual switch control panel. Compactors are constructed of stainless steel and are designed to produce an 85 percent reduction of waste volume.

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 grind chamber — 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. A 5-horsepower compactor features a 1⁄2-horsepower recirculation pump to reduce water consumption. Usually, 5-horsepower compactors consume one gallon per minute. One-, 2- and 3-horsepower compactors consume three gallons per minute.

Standard Features — Scrapping Systems: Some units have a disposer for grinding food waste and use a single plume of water for scrapping. Other models have a disposer for grinding food waste and are installed in a trough application for multiple scrapping stations. There are systems that use a scrap basket rather than a disposer. The large perforated basket collects insoluble food while allowing the solubles to wash down the drain. Another scrapping unit uses a scrap basket, rather than a disposer, and is installed in a trough application.

New Features/Technology/Options: Newer disposers feature energy and water savings controls. At least one manufacturer also factory installs water saving flow controls into the solenoid for water conservation.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 inactivity, conserving water and energy. Another environmentally friendly feature is an automated, self-contained waste handling system that reduces foodservice waste volume by up to 90 percent. This feature also recirculates process water for re-use. Air-cooled disposers utilize a fan, while others run water in an insulated jacket to cool the motor. Water-saving features are also available on some units.

At least one compactor model, geared for front of the house 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. 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 model.

Some scrapping systems use approximately 50 percent less water than freshwater troughs, while others use approximately 80 percent less water than typical pre-rinse/disposer stations and 90 percent less than freshwater trough applications.

Key Kitchen Applications: Disposers are used in dish rooms for disposing of food waste from soiled dishes and in prep areas for grinding up and disposing of trimmings. Pulpers and compactors compress food waste, thereby minimizing the volume of such waste in a kitchen, resulting in lower volume-based trash removal fees. Some pulpers process both liquid and solid waste, reducing 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 pounds 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 back of the house, they also help eliminate pests and reduce the labor needed to haul trash.

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. Water hoses can be used to wash down suspended disposers.

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 and Sanitation Essentials: Incorporating a food waste disposer, pulper or compactor into a commercial kitchen is convenient, and solves critical sanitation challenges.

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