Keys to Building a Successful MRF: Before, During, After

The Building Envelope

Many times, we see owners dictating the MRF building size and then directing the equipment vendors to “fit the system in the building”. Although this is a common approach when retrofitting existing buildings, it can lead to issues down the road. Ideally, you should provide your equipment vendor with a flexible building footprint within a “box” that they can use as a general guideline to efficiently design their system to allow for minimal system turns, excess conveyor belts, vertical layers, and room in and around the equipment for proper maintenance and repairs. At the end of the day, once the facility is turned over, you want to make sure that your operations team can easily reach all the right areas of the equipment to safely conduct their regular maintenance, replacements, repairs, and clean-up duties. This is most easily accomplished if the equipment supplier is allowed input when designing the system.

The need for flexibility when approaching the building envelope comes into play when considering access points around the equipment for forklifts and other machinery and for walkways for employees, visitors, and other guests to access areas of the system. Flexibility also comes into play when it comes to column layout. If the equipment suppliers are told where the columns are, then it limits their layouts. They need the ability to move those around as well.

Long Leadtime Items

In the current construction market, there are several items, such as electrical gear and air-handling units, that can have extended leadtimes up to over a year, so planning ahead is important for any critical path items. While MRFs require a substantial timeline to build (around 12 months or more), it is still important that the long lead items are identified around the 30 to 50 percent design timeframe so they can be procured and delivered to the project site on time or early to avoid significant schedule delays. This process also comes into play while considering certain permits and utilities required for the project.

There are many long lead items that your team needs to stay ahead of early in the design phase to keep the project on track. This is a good reason to have the construction team engaged early so they can help identify the long lead items and actively work to get them ordered.

Experienced AEC Team

Owners often hire Architecture, Engineering, and Construction (AEC) teams that are perfectly capable of building, but may lack solid waste experience. If the firms do not have experience working with equipment vendors and MRF operators, they more than likely do not know what questions need to be asked and addressed along the way. These facilities are not just big, metal buildings that can simply be placed on a site. This is a complex operation with complex equipment that is meant to function at a high level for the next 20 years. Common mistakes that we see are:
• Improper foundation design
• Improper concrete slab design for tipping floors
• Foundations installed for equipment
• Pits not properly designed
• Power drop in wrong locations
• Insufficient access around the equipment for maintenance or future upgrades
• Poor coordination between the fire sprinkler system and the equipment
• Incorrect or poorly located access points
• Inability to modify or expand the building for future needs without significant rework

There are several firms in the U.S. that have decades of experience designing, constructing, or design/building MRFs. Do yourself a favor and work with them. It may appear that they will cost more upfront, but they will save you time and money during construction, all while making your facility more operational and cost efficient—enhancing durability of your MRF for many years to come.

Part 2: Designing MRF Equipment and System Processing

These systems are meant to provide communities and MRF owners with years or decades of service. When designing a new MRF, there are several considerations to make early in the process. Everything from traffic flow and employee safety must be a point of focus from day one.

One of the most impactful decisions to make during design is choosing an experienced equipment vendor that has expansive hands-on experience within the industry, catering specifically to operators of sorting systems who will help guide you through the entire process. MRF systems are complex and expensive investments which is why choosing the right partner matters. The following are important factors to consider during this planning phase.

Big Picture Project Objectives

When you are considering a new MRF, you must first have a solid understanding of what your project objectives are. A lot of detail comes into play with this. There are several questions that are helpful for MRF vendors to know when you first engage with them:
• What space will be dedicated to the MRF?
• What is the material characterization?
• What commodities will be recovered?
• What is the annual tonnage to be processed and within what operating days/hours?
• What is the system budget?
• Where is the material coming from and how long are material contracts?
• Are there foreseen changes in tonnage or material to be processed?
• Is it more important to my project to save on CapEx or OpEx?

Flow Optimization

Once the questions above are addressed, an experienced MRF vendor will work on a material flow diagram. This schematic is done early to give a road map of the facility layout. With the material characterization, a mass balance will be created to identify any system bottle necks to ensure equipment is operating at efficient tonnages. Geographical factors can play a big role in flow optimization, as many regions are subject to severe weather changes throughout the year. Some regions must also account for material changes if they are a destination or a college city for example. These considerations must be accounted for early in the design process to ensure the system is optimized throughout the year.

The main responsibility of the MRF vendor is to have a streamlined process with efficient conveyance of material, which can be impacted by the building space and traffic flow. The schematic material flow diagram is modeled with 3D engineering software to assist system placements within the structure. This model will also be used early to consider system placements in coordination with tip floor, bale storage, employee lounge, bathrooms, viewing platforms, operating rooms, air compressor area, ingress and egress, residue and glass load out, direct bale feed, and all other necessities. This can be accomplished with the MRF vendor working closely with the building contractor with excellent communication across all coordination channels.

Access

Being able to oversee all sorters on the same platform from the operating room is ideal for safety. It is fitting to have your sorters enter and exit the sorting platforms at the safest location, closest to the employee breakrooms and in one location. Maintenance access must also be a point of focus at the beginning of project planning. A specialized piece of equipment, such as a lift or crane, may be needed to maintain and change parts for certain equipment. With this, there must be access from the floor and around the equipment, including any pits, to perform proper upkeep and maintenance. An experienced MRF vendor will provide a maintenance matrix that thoroughly outlines access to all equipment and the tasks that should be performed daily, weekly, monthly, and annually to keep the systems operational and safe.

Future Planning

Proper planning and the creation of system modes will allow flexibility for future material changes or needs. For example, there could be a residential mode and a commercial mode that can run on the same system. By using reversing conveyors and recipes, the same system can be used for different applications. If there are plans to add more tonnage in the future, it is important to think ahead and leave space for an additional line or equipment.

It is best practice to plan upwards of five years on material changes to account for flexibility and space. When possible, it is ideal to oversize equipment like screens, balers, eddy current separators, and optical sorters so these machines do not become your future bottleneck. Upsizing air compressors is also a wise investment to consider as automated machines like optical sorters, that rely on air, are being incorporated into systems as personnel becomes harder to find.