Efficiency cubed

Compactors and balers are a key part of the waste management handling process, with new technologies introducing increased safety and efficiency to operations.

For recyclables, balers are used before and after collection, at the point of generation in the case of many businesses and at a material recovery facility (MRF) in the case of residential material, says Jessica Hart, who handles sales and marketing for International Baler Corp., Jacksonville, Florida.

Compactors also are beneficial for waste handling applications because of their ability to reduce material size and volume by compressing and crushing.

A stationary compactor is a machine that compacts refuse into a detachable container at the site of generation. A precrusher dry waste compactor precrushes large bulky items, such as steel drums and pallets, before being compacted into the container.

A compaction container is a steel-reinforced container into which a stationary compactor compacts refuse. A self-contained compactor is a unit in which the compactor is integrated structurally into the compaction container, and the entire machine is taken to the disposal site.

The charge box is the area, measured in cubic yards, in front of a compactor ram into which refuse is placed. The clear/top opening is the length and width of the opening above the charge box.

Compaction containers are available in octagonal and rectangular styles from 20 to 40 cubic yards.

For compactor installation, a concrete pad is preferred with dimensions of 10 feet wide and a length of 5 feet greater than the combined length of the compactor and container. The pad should be a minimum of 3,000-pounds-per-square-inch concrete, wire mesh reinforced, and 6 inches thick.

For electrical considerations, a lockable fused disconnect box must be within sight and no more than 50 feet away from the main control panel. This equipment conforms to all applicable American National Standards Institute (ANSI) Z245.2/.21 safety standards for compactor operation.

The installation must comply with the recommended ANSI and Occupational Safety and Health Administration standards. The hopper access gate or chute/doghouse doors must have interlock switches.

E-stop emergency controls should be readily accessible to the operator or located within 3 feet of the point of operation, the material feed area or, if chute fed, within 3 feet of the access door.

A compactor consists of five basic parts:

• The body, which is a steel structure that houses all the other parts. It has an area where the material is compiled or a charge box with heavily reinforced sides to withstand the forces of compaction. A breaker bar, made of a heavy steel angle, is across the front of the charge box. This bar breaks oversized objects, such as wood or pallets, before they enter the compaction container.
• The ram is a specially designed steel structure with a heavy faceplate. It moves horizontally through the charge box, forcing the material into the compaction container.
• The cylinder is attached behind the ram and moves it forward and backward. Inside the cylinder is a piston and rod that operates hydraulically. Cylinders vary in size. Larger ones are used in heavy-duty compactors with large charge boxes. Cylinders are sized by their bore and rod diameters.
• The power unit consists of a hydraulic oil tank, pump, electric motor and directional control valve. The oil, under high pressure, forces the piston in the cylinder to move forward and backward.
• The electric panel box contains the transformer, motor starter, relays, fuses and switches that operate the compactor. Most panel boxes incorporate printed circuit boards or programmable controllers for added reliability.

Fitting the application

While compacting waste reduces the size and volume of material by compressing and crushing it and saves money by reducing the number of hauls, those best suited to invest in the equipment include operations generating 30 to 40 cubic yards of material weekly. A vertical compactor could be suitable for such an operation, while those generating 60 to 150 cubic yards weekly could use a stationary compactor with a detachable container or a self-contained liquid-tight compactor.

The volume of waste and its size are two factors to consider when choosing a compactor. Dry waste is compacted efficiently by a stationary compactor. Meanwhile, wet waste is best handled by a self-contained, liquid-tight compactor.

To ensure ease of use, the compactor’s location is important. Consider if its loading height saves steps and labor and is easy to feed.

The amount by which a compactor will reduce the volume of solid waste depends on the type of refuse, the total force of the compaction ram and the type of compaction container. While the average compaction ratio for compactable, mixed waste is 4:1, exceptions are industrial waste consisting mainly of pallets and heavy boxes that might yield only a 2:1 compaction ratio.

Climate also affects compaction ratio—frozen garbage is more difficult to compact than wet garbage.

Kirk Warren, director of product management for Charlotte, North Carolina-based Wastequip’s steel division, says the two most common types of compactors are stationary and self-contained.

“They are the ones haulers and end users are most familiar with, and that’s dependent on the waste stream. They come in varying sizes,” he says. “When used properly, the equipment makes the process safer, easier and more efficient for both the customer and the hauler.”

In doing a site survey, Wastequip representatives want to know how the material is collected, how it’s going to be loaded, how often and the available space.

“It’s not only where the equipment is going to be located—if it’s inside or outside—but making sure that the collection vehicle is not interfering with the operation of the business itself,” Warren says.

“We determine if the size of that equipment fits into the space and confirm the voltage,” he continues. “We want to make sure it’s going to work with the hauler.

“Once all of that prework is done, then when the equipment arrives, certain things have to be done to prep the site and make sure everything goes smoothly so that they can hook it up and employees are trained on how to use it,” Warren says.

A concrete pad is the desired material for supporting the equipment, and asphalt is not suitable. Warren says the concrete pad has to be a certain width, a certain length and a certain thickness to support the weight of the equipment and the waste material, as well as the collection vehicles that will be picking it up.

When the collection vehicle is lifting the compactor and the rear wheels are not resting on concrete but on asphalt, it can create ruts and make it very difficult to pick up, creating an unsafe environment.

“With most compaction equipment, there’s a key switch to turn it on, and you can push a button to operate it,” he says. “The equipment is designed so that it will not operate unless the necessary safeguards are in place.”

Compactors also have lights indicating they are full and need servicing.

Safety is key

When working with end users, Warren says Wastequip tries to understand exactly how the employees are involved in the handling of the waste—everything from how they collect it to how it’s transported and how it’s going to be loaded.

“We’ve designed equipment so we can minimize any injury or accidents to the users and operators,” he says.

If heavy waste is being generated at the site, Wastequip provides carts that take the strain off of the employees.

“They can walk that to that compaction equipment, and it will be automatically lifted or loaded into there,” Warren says of Wastequip’s compactor design.

“You can minimize back injuries and the strain where employees come into contact with the waste just by making sure they have the right type of equipment to load it into the compactor from where it’s collected,” he adds.

Additionally, compactors and balers are incorporating new technologies, such as sensor pads that help ensure an individual will not come into contact with the material when it’s going to become compacted, Warren says.

A version of this article originally appeared in MSW Management magazine, which Waste Today acquired in late 2023.