Two well-known companies, FWMurphy and Miratech Corp., recently joined forces to form Compliance Controls LLC. FWMurphy, established in 1939, is an ISO 9001 registered manufacturer of equipment management and control solutions for off-highway and construction equipment, gas compressors, standby generator controls, irrigation and water pumping. Privately held Miratech Corp. and its subsidiary, Miratech SCR Corp., are leaders in the development and engineering of emission control and engine performance technology for industrial engines. Compliance Controls and both parent companies are based in Tulsa, Okla., and have sales offices located across North America.
"The new organization is dedicated to sales, support and continuing development of its state-of-the-art, user-friendly Windows-based air-to-fuel ratio control systems," said Kevin O'Sullivan, president of Compliance Controls. "We saw a need in the industrial engine marketplace tar more advanced, cost-effective, flexible, easy-to-install and easy-to-use engine control systems. Development of our rich-burn (MEC-R) and lean-burn (MEC-L) air-fuel control systems was a team effort to meet that need.
"Backed by our parent companies' distribution networks, Compliance Controls will focus exclusively on delivering and supporting air-fuel ratio control solutions tailored to our customers' specific requirements," he said. Both control systems are designed for use on carbureted, spark-ignited natural gas and LPG engines. MEC-R is a rich-burn engine control system for use on engines equipped with three-way catalysts to reduce regulated pollutants such as oxides of nitrogen, carbon monoxide and hydrocarbons.
"The controller minimizes fuel consumption while maximizing catalyst performance for precise, continuous compliance. It also cuts engine maintenance and includes a fail-safe diagnostic and troubleshooting system for operators and management," said Bill Clary, vice president of sales and marketing for Miratech.
MEC-L is a lean-burn engine control system that can control fuel with a variety of valves in full-authority arrangements. "It reduces lean-burn engine maintenance costs, enhances performance and improves fuel economy," said Clary. "MEC-R and MEC-L air-fuel ratio control systems are the result of experience gained over the past decade and offer customers a dramatic upgrade in capabilities and user-friendliness at a competitive price," he added.
Jack Maley, vice president of operations for FWMurphy, pointed out that the MEC systems are closer in design to automotive-type air-fuel controllers than earlier engine control systems. "Using a reliable, high-performance air-fuel controller in conjunction with a three-way catalyst is the most effective method of cleaning rich-burn spark-ignition engine exhaust gases available today," he said.
The three-way catalytic converter that simultaneously oxidizes excess levels of exhaust carbon monoxide (CO) and nonmethane hydrocarbons (NMHC) and reduces nitric oxides (N[O.sub.x]) becomes ineffective if the rich-burn engine air fuel ratio differs by more than 1% from the stoichiometric value. The MEC-R system maximizes the efficiency of a three-way catalyst by maintaining a constant air-fuel ratio and continuous emissions compliance over yawing engine loads, speeds, fuel quality, ambient temperatures and barometric pressures. It fits virtually any gas-fueled, carbureted, rich-burn industrial engine with any catalytic converter.
The MEC-R control scheme includes pre-catalyst closed loop, exhaust oxygen ([O.sub.2]) feedback control, post-catalyst exhaust [O.sub.2] feedback; cascade control for fast, real-time adaptation to changing catalyst performance; variable set-point for pre-catalyst and post catalyst exhaust [O.sub.2] control for fast, real-time response to varying engine loads; catalyst temperature monitoring to protect emissions control catalysts from engine and fueling malfunctions; and two-dimensional open loop valve positioning, based on engine speed and load. It drives up to two fuel-metering valves for V engine configurations and can maintain compliance even with critical oxygen sensor malfunction.
Compliance Controls indicated that a crew of two could install and program the MEC-R system on an engine in two days for a new field installation with hard conduit, or less than a day with one technician for a retrofit project.
In addition to fuel control valve(s) and a microprocessor controller in a NEMA 12 enclosure, the system includes [O.sub.2] sensors downstream of the catalyst and in each exhaust bank upstream of the catalyst, air manifold pressure and temperature RTU's, pre- and post-catalyst temperature probes and a dedicated magnetic pickup for sensing engine rpm from the flywheel. The system includes all connectors and a selection of cables that can be cut to length at the terminal end where they connect to a terminal block inside the controller enclosure. A 9 to 30 Vdc power supply is required. The company and many of its distributors provide installation, set-up and operator training.
