Double duty: for this manufacturing shop, bringing in a coolant recycling system provided cost savings while reducing environmental impact.

[ILLUSTRATION OMITTED]

Cost control is an essential part of business competitiveness. At the same time, environmental compliance is also a business requirement. While on the face of it, they may seem competitive, but reducing waste, reusing materials, and increasing efficiencies can offer cost savings and lessen a shop's environmental impact, thus meeting both requirements.

Bimba Manufacturing, Monee, IL, established cost control and met environmental regulations with an onsite fluid recycling program.

The company produces pneumatic and electro-pneumatic actuators for worldwide markets. Its offerings include a line of industry-leading air cylinders, rotary actuators, linear thrusters, rodless cylinders, flow controls, and position-sensing cylinders.

In addition to its standard catalog products, almost half of its business consists of custom and semi-custom products designed for special applications in machinery and automation. They are sold to original equipment manufacturers and end-users, both on- and offshore, in multiple industries. To ensure top quality and fast turnaround, the 180,000 ft2 shop operates a variety of processes using machines with sump sizes up to 75 gal.

The Search for Alternatives

As part of a plant-wide cost cutting initiative, Bimba looked into alternative methods of managing waste fluids.

"We were looking for the most cost-effective method of reducing our coolant consumption and disposing of the waste fluids we generated," Tom Cross, Bimba manufacturing engineer, said.

Max Bailey, at Bimba's fluid supplier, Illini Coolant Management, a Chicago-area distributor of Master Chemical Corp., Perrysburg, OH, had discussed fluid management programs and coolant recycling with Bimba on several occasions. Cross tapped him as a resource to conduct a comprehensive plant survey and present recommendations based on the findings.

The survey included an examination of the plant's processes, which included instances where fluid touched metal. Cross and Bailey also discussed what the shop wanted to accomplish in making any changes.

Illini presented several approaches for Bimba to consider:

* Toll recycling, where crews from Illini would come to the shop after hours and clean machines, recycle fluids, and put fluids back in the machines. This required no capital outlay and provided a reduction in indirect labor for Bimba.

* Installation of centrifuged-based recycling equipment in the facility using Illini personnel as operators. This required a capital outlay but reduced indirect labor costs for Bimba.

* Comprehensive shop floor fluids management and recycling, including the installation of centrifuged-based recycling equipment in the plant with Bimba machine operators handling cleaning, machine fluid maintenance, and recycling system operation. This required both capital outlay and indirect labor costs, but provided control and scheduling flexibility.

Bringing the Coolant Recycling Process In-house

"We chose full-blown shop floor fluids management because it gave us the most control and best return on investment," Cross said. "It promised to extend coolant life and reduce usage and waste, as well as offered the control and flexibility we wanted."

Illini also offered information about different types of recycling and machine cleaning equipment.

Bimba chose Master Chemical's XYBEX System 600, a coolant recycling system designed for plants operating with a single coolant and a total coolant sump capacity of less than 2,500 gal. The system features an easy-to-clean, high-speed centrifuge for tramp oil removal. Bimba calculated the system would pay for itself within four years.

"Maintenance workers installed the recycling system and training took a day," Cross said. Training was done at the machine by the manufacturer representatives.

In this installation, machine sumps are vacuumed and emptied into one side of the system. Clean replacement fluid, available from the clean-product storage compartment of the system, is used to refill the machine and return it to production. The recycling system works on any machine running water-miscible coolant.

"We use Master Chemical's water-based coolant, TRIM E206, in all of our machines, which lets operators recycle all fluids," Cross said.

Recycling the Bimba Way

Bimba uses the recycling system on an as-needed-basis about three times a week. The process takes about 90 minutes, the time needed to recycle 150 to 190 gal of coolant.

"We do it differently than everyone else," Cross said. "We take the dirty coolant from the machines and send it through a coarse filter to remove large contaminants. Then we run the fluid through a 100[micro] filter, after that it goes into a big holding tank."

The coolant contains way oil and often other contaminants, like shop rags and chips, so the operators let the fluid sit for about a day in 55-gal drums. This lets the way oil separate from the coolant.

After that, operators tap the oil, which goes to a waste oil storage compartment and is hauled away. Dirty coolant is pumped into the dirty side of the recycling unit.

The unit has its own 20[micro] internal filter. The fluid passes through that filter and into the centrifuge, which removes more oil and impurities. The recycled fluid goes into the clean tank and from there back into use.

"We don't have a centralized system, but we have drop lines that let operators draw fluid on an as-needed-basis," Cross said.

If the recycled fluid runs low, it is replenished with new coolant. Bimba runs a 50 percent fresh, 50 percent recycled coolant mix. This has helped the company cut the volume of new coolant concentrate.

Fluid Recycling is Environmentally Friendly 

"We learned a fluid recycling system serves both the environment and the plant," Cross said. "We also learned that the process is more than running dirty coolant through recycling equipment; it requires a well-executed fluid management plan, and a well-designed and properly maintained recycling system," he said. "Fluid recycling is different from recycling other materials."

The focus of manufacturing fluid recycling management is the failure mechanisms inherent in working with fluids:

* Mixing and concentration are crucial to maintaining stability. Maintaining the right concentration ratio is essential for efficient and trouble-free results from water-miscible fluids.

* Dirty machines stress the entire system and spread bacterial and fungal growth. The majority of bacteria and fungi live in the matter found on the walls and bottoms of sumps and fluid delivery plumbing. Periodic cleaning is key. Clean machines increase tool life and reduce fluid usage, resulting in lower costs and less impact on the environment.

* Tramp oil contamination is a major contributor to fluid failure and can stress the system until the fluid no longer meets performance requirements. Prompt and efficient removal of tramp oil that does leak into the sump lessens the stress on the system and saves costs and resources.

Cost Savings and Additional Benefits

During the 12 months before installing the recycling system, Bimba used 2,544 gal of coolant concentrate. In the 12 months after installation, usage dropped to 1,944 gal. The 600 gal reduction saved $9,246. Related costs like shipping and indirect labor were not included in the analysis.

"We're pleased with the savings in coolant concentrate alone, not to mention lessening our environmental impact and staying within EPA guidelines," Cross said. "We learned a lot about the environmental benefits of the recycling process."

"We have better concentration control now so we have more consistent tool life," Cross said. Master Chemical Corp.

FLUID MANAGEMENT ADVICE

For anyone considering implementing a fluid management system, Tom Cross, Bimba manufacturing engineer, has advice from his experience:

* Define the problem. List goals and objectives. Work with management to determine the extent of the changes possible.

* Examine each process and review where fluids touch metal. This provides a comprehensive view, and an opportunity to evaluate how each process is working. Then, identify areas for improvements and waste minimization.

* Take advantage of fluid suppliers' expert advice and fluid management services. A fluid supplier can be a valuable resource in reengineering existing processes and implementing recycling systems.

"Take the time to evaluate all of the processes and options," Cross said. "It may be possible to make changes that increase efficiencies and reduce costs while at the same time reducing environmental impact and helping a company stay compliant."