Every solid waste entity deals with the same problems; litter control, vermin, rising operational expenses and ever diminishing space in landfills. Not every facility meets those challenges in the same way and the solid waste division of St Lucie County, Florida, was determined to find a long-term cost-effective solution. The fundamental answer to many of the problems they faced was baling of solid waste, a trend that is gaining significant traction in the industry.
Mr Leo Cordeiro, Solid Waste Manager at St Lucie Solid Waste Authority; investigated whether to consider baling garbage, and it didn’t take very long at all to come up with just the opposite question “why aren’t people doing it?”. He says “When you look at the benefits, it was so obvious that what we’re doing is just so defunct, there’s no comparison, no reason not to do it. We have 1100 pounds of garbage in every cubic yard of air space (656 kg to every 1 m3). And when we look at baling it, we can do close to double the volume and reduce cover, litter and leaching. You’ve got to ask yourself why am I not doing it?”
A new Solid Waste Facility was designed with separate unloading and baling areas, immediately establishing a very effective and controllable workflow. The power behind the St Lucie facility, are dual Macpresse MAC 112 Balers. Every aspect of the MAC 112 has been calculated to increase productivity, reduce operation costs with much lower kilowatts per hour, yet producing up to 70 tonnes of baled material per hour depending upon moisture content and infeed density.
How are these impressive production numbers achieved? The difference is in the design. From the first look of the MAC 112, the built-in strengths are evident. The overall layout is the product of 50 years of Macpresse experience. The efficient material flow path and the horizontal baler orientation already increase production speed and make bale sizing very easy to change.
Solid waste is delivered by the staged conveyor belt system. The conveyor in the pit transports the material to the inclined conveyor, which travels at a slightly higher speed. This delivery technique spreads out the material more evenly, thereby increasing system production.
The 112 incorporates a single ram continuous feed design, bringing efficiency and producing high hourly production rates. Powering the strong compaction ram is a high-pressure hydraulic system designed around Rexroth variable flow piston pumps and high efficiency electric motors, allowing one or both motors to operate independently.
Delivering the hydraulic energy to the baler is the patented hydraulic manifold block which reduces hydraulic shock and is designed to keep oil temperatures consistently low to enhance the hydraulic functions. Hydraulic and mechanical forces applied to the material in the chamber produce dense square bales.
During compression, leachate is gathered by conveyor systems, dust is mediated by the filtration system, and both are reintroduced into the waste stream.
Once sized, the bales are easily cut with the two-stage serrated shear. This ingenious design eliminates shear shock and eliminates the need for a pre-press flap apparatus. The compressed material is then tied by the five-wire mechanism which positively feeds each wire into the twister assembly preventing missed wires and wire ties. All five wires are tied simultaneously to reduce tying time.
This entire system is controlled from an electrical control panel. All functions of the MAC 112 are easily executed using state of the art Programmable Logic Control technology which also offers an optional Supervisor system that provides real time diagnostic functions with data exported into excel for cost analysis.
Maintenance considerations are an integral part of the design of the MAC 112, with motor and pump areas which can be completely exposed and panels opening wide for maintenance issues. Safety was not sacrificed in the interest of speed or flexibility.
Has the Macpresse total solution design been effective? In 1989 it was predicted that in the year 2002 the St Lucie landfill would be full. Through good management and the implementation of baling, the landfill now has life expectancy to 2050 and capacity of 13,886,728 cubic yards.
“Here at St Lucie County the baling process is going to save us over ¼ million dollars a year in operation costs by eliminating compactors scheduled every three years, operator salary, and diesel fuel at 60 gallons per day (273 ltrs). The biggest saving is in daily cover material. Operators from the waste companies are in the landfill 80% less time, residents don’t see numerous birds or blowing litter – all that has been solved with baling.” declares Superintendent, Mr Ron Roberts.
Mr Leo Cordeiro, Solid Waste Manager explains “In the research we did, there were two balers to choose from. After we looked at Macpresse they told us; we’ll deliver the machine, it’s not your machine until we have it running, and we will guarantee density; as well as being $250,000 cheaper – you’ve got to be foolish not to look at it.”
“Through the whole design process and construction of our facility, Macpresse were there 100% of the way, working with us not against us. Giving us the best, we were looking for and trying to achieve the best design in the United States of a baling facility,” finished Mr Roberts.
CEMAC technologies represents MACPRESSE in Australia.
Contact: CEMAC technologies P: (03) 8400 6066 E: firstname.lastname@example.org W: www.cemactech.com