ENEL launches a new LWT automated PLC-controlled dredge in Guatemala

SOMERSET, WI, Nov. 13, 2006 -- Enel Latin America asked Liquid Waste Technology LLC to design a LWT Pit Hog™ dredge equipped to excavate the main pond's sediment from the Santa Maria River automatically.

Enel Latin America needed a solution for removal of sediment accumulating in the power generation water supply at its Greenfield El Canada Power Plant in western Guatemala at Zunil. Enel Latin America asked Liquid Waste Technology LLC to design a LWT Pit Hog™ dredge equipped to excavate the main pond's sediment from the Santa Maria River automatically. The LWT Pit Hog™ dredge was the efficient and economical choice due to its durability, low maintenace and low associated labor costs.

Enel is a US$50 billion diversified utility, among the three largest based in Europe, whose North and Latin American operations include over 70 clean power plants based on renewable sources such as hydro, wind, biomass, and geothermal with a combined output of over 600MW.

LWT specifically engineered the Pit Hog™ dredge to excavate the main pond's sediment from the Santa Maria River while maintaining optimum production levels. This project is Enel's second in Guatemala . Enel Latin America is dedicated to the development and operation of renewable energy power plants in Central America expects the new plant to add 43MW of capacity.

LWT and its representative Felix Montes of Femco S.A. in Guatemala worked closely with the Enel Latin America engineering team to design, manufacture, and install an automated dredging operation. Enel's engineering team of General Manager Ing. Juan Carlos Méndez and Plant Manager Florencio Gramajo visited the LWT plant in order to specify the correct controls, capabilities, and specifications to remove the sediment material effectively and at minimum cost.

Florencio Gramajo Enel's Plant Manager, said after the initial installation: "We have been able to keep the pond's sediment at the same level with the LWT dredge even when the rainy season is at the highest". Michael Young , LWT's Service Manager, indicated "While the inflow from the river and the amount of material already present made the job difficult, the operators were operating the dredge efficiently within just two days." According to LWT Service Technician Fred Hoffman "The customer was very impressed with the density of the material being pumped. They stated on several occasions that the discharge was much thicker than they had expected."

An Allen Bradley Panel View 600 Operator Interface at both locations coordinates the various functions and controls. An LWT radio system provides the link from dredge to shore.

Liquid Waste Technology is the world leader in designing remote controlled dredging systems. LWT's remote controlled systems can be operated via multiple methods, including hand-held radio remote control transmitters and fixed shore mounted control panels. The LWT Pit Hog dredge is designed to remove sediments from reservoirs, settling lagoons and wastewater treatment ponds. The Pit Hog excavates and transports these settled solids as slurry through a piping system to a pre-determined location.

LWT's low voltage electronic controls make possible totally automated and remote controlled operations. LWT programs a PLC (programmable logic controller) to control the dredge's automated functions and control loops, minimizing labor and maximizing production of solids at the set flow rate. This system is ideally suited for providing material to both de watering and continuous process systems. LWT supplies components and provides customized operational features to meet any project's specific operational needs.

Heavy duty steel pontoons provide the necessary flotation to support the on-board machinery and equipment in the water body. Principal features include the auger (excavator) head, submersible slurry pump, boom, boom hoist, traverse winch, electrical controls, and hydraulic system.

The functions of the auger head and the submersible slurry pump are essential for effective solids removal. The boom hoist positions the auger and submersible slurry pump vertically in the sediment while the traversing winch propels the machine forward and backward along a wire rope cable anchored at both ends of the lagoon. This proven design provides one of the most cost effective means of hydraulically dredging sediments on the market today.

The system utilizes a LWT designed rail type lateral move system for positioning and anchoring the winch traverse wire rope. Generally the system is comprised of two parallel rails located on opposite ends of the pond with the traverse cable stretched between them. The traverse cable is threaded through the treble sheave winch and cable guides on the dredge which propels the dredge forward and backward. After the floating discharge hose and/or pipe are connected to the dredge, it is ready to operate.

Liquid Waste Technology LLC (www.lwtpithog.com) is based in Somerset, WI.

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Also see: "LWT Dredges Aid Southern California's Water Needs"

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