The Anatomy of a Waste Handler
Posted on: 25 Apr 2014
Working in waste and recycling facilities may be one of the more heavy-duty jobs for the purpose-built wheel loaders that we call waste handlers. These robust machines are outfitted with a number of features and performance enhancers suited specifically for work in these applications. An extensive availability of attachments from forks and grapples to buckets with rubber cutting edges make these machines extremely versatile. The right machine for each application will depend greatly on the available operating space, the type of material being handled and the operational demands put on the machine. In this article we’ll examine key factors to consider when evaluating waste handlers and new technologies that may help your operation run more efficiently.
Understanding your Tier 4 engine options
The buzz of equipment manufacturers talking about Tier 4 engine requirements is growing to a deafening climax, but there are important things you need to know when considering waste handlers. There are two primary solutions available in this equipment category: Selective Catalytic Reduction (SCR) and Cooled Exhaust Gas Recirculation (CEGR). SCR is an after-treatment system that creates a chemical reaction by adding diesel exhaust fluid (DEF). This transforms NOx into nitrogen and water, which occur naturally in the atmosphere. CEGR operates differently: exhaust gases are cooled, blended with recirculated exhaust and returned to the cylinder, which lowers combustion temperatures and reduces NOx. Particulate matter (PM) levels are then reduced through the use of an after-treatment diesel particulate filter (DPF) system.
The biggest differentiators in recycling and waste applications come in terms of responsiveness and the heat produced by the engine – and in this application, SCR technology offers distinct advantages. SCR results in lower temperatures in the exhaust system while optimizing combustion with no downtime or extreme temperature spikes (compared to regeneration found on machines outfitted with CEGR technologies). An excellent side effect of this is lower fuel consumption by nearly 20 percent.
SCR is the practical choice for waste handlers because its tasks are variable, which creates inconsistent engine loads and power demands, as well as extended periods of idling. CEGR requires consistent engine speeds and temperatures to burn off the PM. If those temperatures are not met, the CEGR engine requires manual regeneration, which spikes engine exhaust temperatures and requires the machine to run for 10-20 minutes (without being operated) until the PM has been burned off. Manual regeneration with CEGR equates to downtime, while SCR lets the engine run at peak performance by using after-treatment, ensuring strong lift capacity and pushing power, as well as consistently fast cycle times and optimal uptime.
Keeping temperatures down in waste handling applications is also critical in order to prevent thermal events from occurring. These machines often work in tight quarters with excessive amounts of loose and potentially flammable material. While the machines often come with cooling and fire suppression features, SCR engines inherently keep the average operating temperature lower than CEGR engines. Engine sealing and cooler areas need to be inspected often, especially if coolers are stacked and advanced cooling packages haven’t been installed.
Take the environment into account
Size is important because many of these machines work in relatively tight/enclosed areas. Bigger is not always better – much of the waste material in transfer stations and recycling centers can be relatively light (when compared to other common applications, such as aggregate mining). Machine size should be dependent on a careful study of the physical size of the facility and the expected volume of material to be handled. Lift capacity becomes more of a critical factor when dealing with heavier waste materials, such as scrap metals, glass recycling and high-density materials such as asphalt shingles.
Potential buyers should examine the total length and width of the waste handler, as well as test it to see how it operates with short, quick cycles in a tight envelope. Understanding its turning radius and the pocket it can operate in is important.
Key things to look for in the cab are the visibility from the operator’s seat down to the bucket and to all sides of the machine, as greater visibility allows the operator to identify potential safety hazards. Some models offer sloping rear hoods that further improve visibility. Rearview cameras are also excellent additions. Joystick controls provide a significant advantage over a steering wheel, as joysticks allow the operator to execute short cycles much more effectively than with steering wheels and with less effort by the operator. Joysticks also improve overall machine responsiveness and reduces operator fatigue.
Customizable guarding packages offer the right amount of protection
Waste applications are nasty on equipment. That’s less of a comment on stench and decay and more of a comment on the odd shapes and sizes of objects found in waste handling operations, and the uncanny ability of those objects to get stuck in critical operating areas. Guarding packages are an important component to any waste handler for absorbing impact and ensuring equipment uptime, and most manufacturers allow you to customize that guarding package to meet the demands of each application.
While all guarding options are valuable, including those that protect the drive train and other critical systems, a few important guarding options to consider are:
- Material ejectors: these ejectors protect the cylinders and hoses critical to bucket lift and operation by ejecting materials that could otherwise gather in the cylinder pockets between the handler’s arm and the main frame of the machine.
- Metal-wrapped hoses: If one of the hydraulic hoses that controls bucket operation becomes punctured or damaged, that machine goes down for repairs. Metal hose guards help prevent damage to these hoses and the associated downtime.
- Windscreen guard: operator safety is of utmost importance. A caged windscreen guard helps protect the cab from debris that could potentially break the window and enter the operating space.
- Fire suppression systems: A must-have in some waste applications, especially tight quarters with flammable materials, these systems are often built in to the machines and provide operators a quick and easy way to extinguish fires that may occur due to the accumulation of debris in the machine.
- Reversible fan: helps prevent obstructions, potential thermal hazards and overheating of the engine.
Solid tires provide durability, added strength
Standard radial tires found on most wheel loaders are prone to puncture in waste applications. Solid tires – both of the slick and treaded varieties – are common in waste applications to prevent puncture damage. Slick solid tires are more common in indoor applications on cement surfaces, while treaded solid tires are more common in outdoor applications. It’s important that waste handlers with solid tires also feature a more robust axle design. CASE’s waste handler, for instance, offers a heavy-duty axle design that is capable of withstanding 60 percent more load than standard models.
One of the biggest advantages of a solid tire and the more robust axle system is the added weight on the back end of the machine. This added weight serves as ballast that significantly improves pushing operations, improves lift capacity and can allow for the use of larger buckets/attachments.
The advent of telematics modernizes equipment maintenance
A telematics system communicates critical machine data via GPS to a web-based software program. This simplifies storing, organizing and reporting of that data. Originally made popular in on-road trucks and commercial vehicles, telematics has found a niche in heavy equipment operation for its ability to modernize machine maintenance practices and improve overall fleet management. It is also a critical tool in monitoring Tier 4-related data (DEF fluid level, CEGR regeneration information) and helping fleet managers identify operator inefficiencies such as excessive idling.
As a web-based system, telematics requires no expensive upgrade to a company’s IT infrastructure and can be implemented almost immediately upon a piece of equipment being put into service. Maintenance intervals and key machine health indicators can be monitored, and alerts can be set up when a machine approaches a scheduled maintenance session or exceeds a desired operating parameter (such as excessive engine temperatures) – all helping to prevent failures and downtime before they occur. Bottom line: technologies are now available on waste handlers that arm fleet managers with actionable data to make smart business decisions regarding equipment performance and utilization. Most importantly: it helps keep operating costs down.
These are just a few of the considerations that should go into your waste handler purchase. Always consult with your local equipment dealer/sales representative and carefully weigh your options based on the physical space you are working in, the material you are working with, and the production demands of your operation.