In the current economy, many have tightened their belts as tight as they can go. But sometimes new equipment can bring in new revenue that will allow for a more efficient facility.
Increased organization, product evaluations, making sure you have the right equipment for the job, maintaining that equipment, and automating can also help with efficiency so that a MRF can loosen that belt a notch or two.
MSW Management talked to MRFs and manufacturers to find out what MRF operators can do to make their operations more efficient, particularly now in the face of rising energy costs.
In Palatine, IL, Wendy Gold and co-owner/brother, Rob Lenzini opened a MRF in 2005 called MBL Recycling. Since then, hundreds of thousands of tons of C&D material have been recovered and returned to the global marketplace. MBL recycles brick, steel, concrete, shingles, wood, nonferrous materials, cardboard, and plastic.
Lenzini and Gold have recently increased their efficiency at MBL through the purchase of equipment that is making better use of materials. Recently, they added an electric EC-266 Rotochopper wood grinder into their process to grind their wood in-house so that it meets a spec. “With this equipment, we can process wood right at our facility and sell directly to the power plant,” says Lenzini. “Before, we were actually paying to get rid of our wood because we weren’t grinding it; now we’ve truly increased our efficiency by treating it here—in addition to making it into a product that pays us back.”
MBL also has just added an Excel baler to its lineup to deal with cardboard coming into the facility. As with the wood grinding equipment, the company’s Excel Manufacturing baler enables it to be paid for materials such as cardboard, which can be baled. “We made money on our cardboard before; but it’s worth more if you bale it,” says Lenzini. “Our baler is also usable for plastics. Before we had the baler, we shipped everything loose and had to haul it to the plant ourselves. There were many cost factors involved. Now we don’t have those trucking costs. We simply load it into our truck trailer, and the company we sell to pays to ship it. Our new equipment will pay us back and then some, every year.”
|Photo: Oliver Mfg. Co.
The Allen-Bradley interface simplifies operation of Oliver’s Maxi-Cap Platinum gravity table.
Safety, Quality, Productivity
ReCommunity, of Charlotte, NC, has 18 MRFs and one transfer station the company has designed, built, and/or operated. The company markets in excess of one million tons per year and has 650 employees who work in Georgia, Florida, North Carolina, Connecticut, Michigan, Wisconsin, New York, Pennsylvania, and Tennessee.
Its tagline is “Leading the Recovery Revolution” with a goal to build a businesses for a better environment, according to Sean Duffy, president and chief executive officer. “The three components we use to maximize efficiency are safety, quality, and productivity, in that order, and that does not change. We have one of the best safety records in the industry; our quality is second to none; and in our productivity we’re always striving for continuous improvement to have the most efficient facility. But we don’t want to give up safety or quality to just have throughput—or have so many tons per hour go through the system. If you are safe, you will naturally be more efficient. Injuries mean downtime, loss of precious time, and injury to human resources, any company’s most important asset.”
Part of ReCommunity’s partnerships with municipalities is to help them design upgrades to their facilities. The company provides the capital and equipment and installs it. It recently assisted Mecklenburg County, NC, with the design of its MRF specs. A $7.5 million investment was overseen as this facility was taken from dual stream to single stream. This conversion caused a 30% bump in volume at the site.
“Our group was certified ISO-14001 in that facility, the only MRF in the US to achieve this, to my knowledge,” Duffy says. “Our trained staff deals directly with issues relating to efficiency; we have a manager of permits and compliance who also addresses all of our carbon footprint and fuel efficiencies.”
Every single aspect of the operation is studied to make sure things are being done efficiently and that all actions are being recorded to make sure they are the best in the industry and business, according to Duffy. The company’s vice president of operations, David Lank, handles the Lean manufacturing and 5S oversight. Lank continually questions every process at the facility to re-engineer issues and problems if they arise. “Finding the root of the problem at the beginning and correcting it will be more efficient, giving you greater uptime.”
Important First Step: Finding the Right Equipment
Pre-selection of specific types of MRF sorting equipment for various locations is really the key to efficiency, according to Charles Winum, waste market manager of Steinert US LLC. “From our experience, it’s one of the things that’s terribly overlooked; unfortunately the result can be anywhere from very complicated and troublesome to catastrophic. The proof for this really shows that a little more time at the planning stage can make life so much easier and the equipment so much more effective later on.”
This Bollegraaf single-stream system automates many of the separation activities.
The clients Steinert deals with vary from people who already have a concept in their minds as to what size or type of machine is needed, to people who have no idea what they’re looking for but just want to separate. “What we do is to try to ask many questions up front to determine what they are trying to achieve,” adds Winum. “Then we go from that point on and say okay; we have enough information or we don’t have enough information—let’s talk.
“This could include a visit to the site, a phone call or an exchange of information by e-mail. It can vary a lot at that stage. But the key element is to get a firm understanding of what the customer is trying to achieve. Once we understand what that is, then we can select an item and have confidence that it will do the job. We also offer a free testing of sample material, just so we can be sure that the results will equal the expectations.”
In the MRF environment, Winum has seen situations where people decided on the conveyor belt that was going to be calculated to handle their volume, and they selected a piece of equipment that should have been enough. “However, in actual production, the volume increases and the material is so high on the conveyor belt that there is no way that the volume can be efficiently processed,” says Winum.
“Separation equipment can either be magnetic or optical, but in either case, equipment throughput is volume-based, not tonnage-based. The volume of the material going through a given width of conveyor belt is absolutely critical to us sizing the unit properly.”
If it is sized properly, then the presentation of the material—and that is the ultimate key—will be in a singulated fashion. Material must be spread out across the belt so that the sensors have a chance to do what they’re designed to do in giving the user good separation. Making the correct choices at the planning stage will ensure the material is spread out so that the machines provide optimum recovery—and maximum payback to the client, according to Winum.
There are a whole variety of things that need to be taken into consideration before you ever get to the stage of having the separator do its job, like the screening process, how material is thrown onto a belt and conveyed, the mount of pickers up front, and their efficiency.
Changing some of the structural work or changing some of the infrastructure of machines and/or picking sections can have costly effects. More downtime or rerunning the machine is not getting the user the efficient payback they should be getting. What is as bad as the losses incurred from additional power outlays, is that the machine loses efficiency. The product they should be deriving revenue from is actually becoming an expense.
“If your plan is as efficient as it can be upfront, then there are no surprises and everything works together,” says Winum. “Separators today are getting more and more sophisticated, however some operators try to cut costs and standard maintenance procedures are not always followed, as recommended.
“If you expect the machines to operate properly, they must be maintained. And that’s not just ours. It’s balers, conveyors, and the like, and it sounds so obvious. But, yet, there are a lot of places that just don’t believe in it.”
Materials and Flow Lines
The Rocky Ford, CO–based Oliver Manufacturing Co. Inc. “wrote the book on separation performance,” explains Jim Thomas, in sales and engineering with Oliver Manufacturing. For those who want to get efficiency and energy saving down to a fine art, Oliver’s gravity separators (also known as air tables) can reliably and consistently grade product or separate desirable materials from contaminants. This equipment uses a balance between the vertical flow of air, consistent product feed, vibrating table friction, and four-axis tilt. Any material of uniform size but varying densities can be separated into lighter and heavier components, in nearly infinite gradients.
“Efficiency has always been our bread and butter. We sell that to our customers as much as we sell them machinery and equipment. It all goes together,” says Thomas.
What this means is that efficiently set up separators can provide significant and quantifiable improvement in performance of the products they process. This performance can result in a quick return on investment and continual process performance improvement that can last decades.
To receive such results, a few basic rules must be followed, like matching the material to the processor and setting up your machine correctly and adjusting for optimum output, according to Thomas. Everything from feed rate to fan speed can improve the quality and repeatability of your separation. Machines with more adjustments give you more control over the results. Automation speeds setup and allows lightning-fast changeovers.
Each and every material has specific characteristics and must be treated separately, Thomas explains. The primary step is evaluating the material: What materials are you receiving and in what quantity? Evaluate the details, such as size, weight, color, moisture content, flowability, and any other details you can measure and put a value on.
What products have value and how much (quantity and percentage)? How much increase in value by cleaning? Cost of cleaning? Payout time? What or where is the market for the end product? Are there political incentives or restrictions?
All products have the same general flow line, but the details are related to the product. Determine a flow line and what details are necessary for your product. Thomas suggests evaluating the following:
- Receiving—Volume? Rate? Equipment?
- Storage—Volume/weight? Time in storage?
- Processing—Sizing? Density? Color? Shape? Texture? Magnetic?
- Storage of cleaned products—How many different products? How much volume/weight per product? Value of stored products? Market for end product?
- Waste product—How do you get rid of it? What is the cost? Does some of it have value?
- Packaging and shipping—Bulk? Bags? Boxes?
- Sales—Can you sell what you produce? You can produce the finest product in the world and it has no value if you can’t sell it.
- Warranty and follow-up—Repeat sales are the result of good service the first time. What do you guarantee? Do you follow up?
Finally, in any process line there is the material handling factor. Material handling occurs at every step from receiving to shipping and at each detail or sub-step in between. Even with a proven flow line, the output can be downgraded or diluted in the handling processes.
The second and continuing step is efficiency evaluations. Every step and detail must be evaluated for efficiency: Ease of handling? Damage to product? Loss of product? Misdirection of product? Labor availability, experience and knowledge?
Efficiency must be rated on a periodic basis. More frequently for valuable products and less often for products that are not so valuable. Even the waste products need to be evaluated. What is the cost of getting rid of waste? Can all or part of the waste be salvaged and sold to reduce the cost of hauling it away?
There is no final step—any processing plant must evaluate, change and upgrade to meet current conditions. Management must know what capabilities it has and use it for that step in the process. Operators must know the equipment and what is required in the output product. Periodic maintenance, upgrades and operator training are essential for optimum production.
“Machines that shake for a living can go out of adjustment from time to time,” says Thomas. “Pick ones with a good reputation for solid construction and keep an eye on performance. The best built ones can last decades. We know, because there are Oliver separators that are working as well today as when we built them, back in the 1930s.”
|Photo: MBL Baler
MRF equipment such as MBL’s recycling balers are rugged workhorses of the industry.
A Metering Bin Up Front to Streamline Operations
Periodic maintenance will help the system run more regular throughout the working shift, because when you have a lot of downtime due to lack of maintenance, that’s one of the big points for loss of energy, according to Michael Drolet, sales support manager at Machinex Industries. “Shutting off and turning back on the various parts of your system has an impact everywhere,” explains Drolet. “Your tipping floor management is impacted by that, and electric consumption is affected when you shut down and start back up. Periodic maintenance is a factor with perhaps biggest impact. Daily maintenance is often neglected.”
Other things users should consider in continuing to feed machines and have a regular process is the setting up of the loading station with the metering bins. That helps in reducing the workload of the loaders. All those recycling facilities are used to having big loaders to feed the system.
“If you have a metering bin in front of the system that you can load with material for 15 to 20 minutes, it avoids the loader doing several runs,” says Drolet. “Any kind of metering device that is self-sufficient for a certain period of time is a great help. If you set up the system in-feed with the metering device, you can reduce the workload of the rolling equipment that you have to deal with in a recycling facility. Whatever type of system you have, you want to reduce the workload of those to a minimum because that’s one of the big energy eaters.
“Other than that, selecting the right kind of equipment is important for a new customer. But we are a custom-designed system so this is not really an issue.”
Machinex installed a system in the UK earlier this year that has no loaders involved with it. Everything is done with an overhead, automated crane. “It’s just an orange peel grabber on an automated overhead crane,” says Drolet. “The crane itself does the floor management, so there are no more loaders to feed the system.”
Machinex is trying to get such innovative systems set up over here in North America, but he is fighting against the fact that in North America operators are used to working with loaders, despite how energy-inefficient they may be. “We strongly believe that the cranes are a better, less-expensive, and more efficient option for large-capacity systems. Compared to Europe, right now the energy costs in North America are not enough to help us push that kind of solution here—yet.”
Trucking Fuel Efficiency
Being able to compact a material into dense blocks can make a big change in the options for marketing that material, as MBL discovered with its cardboard. A MRF that accepts and processes a high volume of EPS Foam for recycling may be able to gain more efficiency with the EPS Foam Densifier made by Bright Technologies, a division of Sebright Products Inc. The Densifier is used primarily to facilitate the recycling of various expanded plastic foam products (expanded polystyrene). It compacts plastic foam into dense manageable blocks that can be shipped economically.
Bright Technologies EPS Densifiers are designed, manufactured, installed, and serviced factory direct in the United States. The first EPS Densifier made in 1995 is still in service today, according to Jeannie Bolt, Sebright Products marketing director. EPS densification machines operate with minimum operator attention. The large feed opening on both the D30 EPS Foam Densification Machine and the D120 Densifier help keep the foam moving and minimize bridging in the bag hopper.
The D30 can process more than 300 pounds per hour with an output density of 16.5 to 20 pounds per cubic foot. The D120 can process 1,100 to 1,300 pounds per hour with an output density of 16.5 to 22 pounds per cubic foot.
With a truckload capacity of 40,000 pounds, compared with baled EPS foam with an approximate truckload weight of 6,000 pounds, or loose EPS foam with a truckload weight of 2,000 pounds, the Densifier can provide optimum efficiency in vehicle fuel costs.
Bright Technologies also has a hydraulic ram press designed for the separation (dewatering) of bulk solids from liquids for fibrous or bulks solid materials that are saturated with liquid and a hydraulic ram press designed for the separation (depackaging) of liquids from their containers usually for the purpose of recycling the container. It is suitable for use with plastic, aluminum and tin cans, and paper-based containers.
Efficiency With Balers
MRFs are 20/6 operations, with 40 people per day. They save money mainly by running. Every hour they don’t run means costs rise all around. During their operation hours, they want to reduce the amount of power with high-efficiency motors. These get better every year, according to Wilfred J. Poiesz, Van Dyk Baler Corp.’s western region sales manager.
“They are about 15% more efficient than they were five years ago, and about the same cost. Our balers contain components that let them run at higher pressures and speeds. The pressure translates into denser bales, which means we can store more tons in the same square footage. The square shape means they can stack them higher, more weight per bale so there is less wire cost per bale, and when bales are forklift-transported you transport more tons each trip, saving on fuel and mileage.”
More modern machinery can cut down the number of forklift operators by 50%. Weight in trucks is more easily distributed, and denser bales mean fewer trips for the trucks now carrying more weight so they don’t lose any time in redistributing the weight over the axles during the course of loading the trucks.
“This is a bigger issue than most people think,” adds Poiesz. “In plant designs, companies often place balers close to the loading dock, so there is less forklift traffic. It’s difficult for one forklift driver to keep up with taking away 50 to 60 bales per hour. It’s a whole different game if you have to drive 50 feet as opposed to 150 feet to remove the bale. Other factors they will keep an eye on in design include keeping trucks from having to drive too far into the plants and the use of bulk feeding options, as the more the material is evenly spread out the better every component in the system can handle it.”
By getting a more even feed, we see efficiency increases of 15% to 20%. Place a drum feeder in a plant, and you see at least a 10% performance increase. The placement of every component affects the efficiency of the plant, and identifying bottlenecks maximizes production.
Sometimes the plant has to be studied after six months to identify where the bottlenecks are located.
“High performance, efficient and robust equipment comes at a price,” says Poiesz. “With that, we do bring to the table as well, that ours has the lowest operating costs, lowest labor count, and highest per-ton rate. We must prove and show where those saving will come. Our customers want to see long time reliable equipment with quick financial returns.
“As the percentage of residue and cost per ton to dispose goes up, it’s important that we maximize recovery thereby avoiding disposal costs. Processors have to pay for the trash percentage in their incoming loads, sort it out, and then they have to pay to have it disposed of. It’s very important to maximize recovery.”
Keeping Odor at Bay Helps with Efficiency
“Odor control is probably not the first thing you think of when the word efficiency comes up. But all these things are connected and in the end contribute to overall efficiency at MRF operations,” says Jesse Levin, area president, NCM Odor Control.
NCM is able to engineer, install and service odor- and dust-control equipment. It ties in its multizone odor-control and dust-control systems to make it easier for site operators to use on an as-needed basis throughout the working day.
This leads to less water consumption and less odor-control product wasted through the use of dust- and odor-control systems in areas that do not need it. “Some odor- and dust-control systems run as an entire unit, meaning every spray nozzle is on at the same time,” adds Levin. “That is where our multizone systems come into play: They give the operators more control.
“We also offer system maintenance monthly, annually, for winterization of systems, and spring startup. This allows site operators to focus on other important operation factors and depend on a reliable service to ensure the site’s odor- and dust-control equipment are running at 100% all the time. It also gives site operators the reassurance that they can call upon a trained systems technician 24/7.”
NCM is one of the few companies that is a fully integrated odor- and dust-control company, according to Levin. Its manufacturing plant in New Jersey carries ISO 9001:2008 certification.
“The combination of producing dust- and odor-control products combined with our ability to engineer, install and service our dust- and odor-control equipment is what makes us a fully integrated company,” he says. “We have been doing this for over 20 years.”
Walking Materials to Where They Need to Go
Bins on the sorting lines at MRFs may contain Keith Walking Floors so that they can automate the walking of the corrugated, plastics or whatever item needs to be sorted, creating an even more efficient and energy-saving work environment. The floor can be turned on and the material goes straight from the bin to the baler.
“We work with a MRF in Rotterdam, Netherlands, where the material coming in, called building rumble—brick, concrete and stone—goes from a Keith Walking Floor, and is metered to the belt that takes it up to the pick line where the brick is taken out of the mix, as it has high resale value,” says Dan Jackson, sales and costing with Keith Walking Floors. That’s different than what most might think of as a MRF application such as papers and plastics. Obviously, building rumble is quite a bit heavier.”
The MRF had been having a lot of maintenance and lack of efficiency issues because as they dropped the bucket of stuff on the incline taking it up to the pick line it was also creating a lot of maintenance needing to be done on the conveyor, according to Jackson. “Our floor was able to meter the material onto the conveyor at any speed they wanted—and almost all their conveyor problems went away.”
Keith Walking Floor drives now come in sizes for smaller and smaller systems, making for even greater efficiency. A growing market for the firm is the KMD-175-drive, 5-ton-rated system for unloading shredded paper, because it works excellently, according to Jackson.
“The main thing we do at MRFs is we are in either the bins, where they’ve already sorted the materials and are moving it to a baler, or we’re at the other end, where we’re feeding material in at metered rate like a surge bin.
“This can be engineered to whatever size you want. If you wanted to feed a semi-load worth of material you could meter that in at a slow rate to the pick line so you don’t have to feed it as often. This allows a loader to go and do other work while material is slowly being fed to the pick line. This increases efficiency and cuts down on fuel costs.
“In some MRFS the materials are semi-segregated. Others have mixed materials. Having things as coordinated as possible helps, and if you don’t have our floor under the pick line, front end loaders are either pushing it through or digging it out. There is a possibility of someone getting hurt as well as the fact that you have a machine running under a pick line where people are working; you can have exhaust issues,” says Jackson.
These are so many things that can be done to achieve better efficiency, and MRF operators can re-evaluate every piece, side and corner of the operation as time goes on. Big changes, like new equipment can have drastic improvements. But even small changes can add up to achieve a well-kept house of materials recovery.
Peter Hildebrandt writes extensively on engineering and scientific subjects.