GEA supplies decanter for leading paper and packaging manufacturer in South Asia

Information about the technical background of the project

CF decanters from GEA specially designed for separation and dewatering for chemical and mineral processes
GEA has developed the Flat Pond 6° decanters specifically for clarification and dewatering in chemical and mineral processes. The decanters are made of duplex steel. A special property of duplex steel is its high corrosion resistance, for example against surface corrosion, localized corrosion, pitting corrosion and stress corrosion cracking. Due to the high drum speed, solids settle on the inner drum wall and are continuously discharged by the built-in screw conveyor. Due to the comparatively large solids discharge diameter, the 6° shallow pond design results in a significantly higher dry solids content in the solids discharge and thus a high G-force at this point. The decanter centrifuge has special rinsing equipment so that no application-typical solids deposits can form on the solids catcher, in the bowl, on the bowl shell and in the discharge. The entire project consists of the Valmet recovery boiler, the "Valmet AshLeach Duo" and the electrostatic precipitators (ESP). Electrically charged ionic compounds (chlorine, potassium, sodium, sulfates, carbonates) are collected by the electrostatic precipitator from the combustion process, fed into the ash leaching system and mixed with hot water. The valuable ions, such as sodium and sulfate, are returned to the process by the decanters, while undesirable ionic compounds, such as chlorine and potassium, are removed. The ash leaching process helps prevent corrosion in the expensive recovery boiler and reduces deposits in the chemical recovery boiler. Corrosion of the boiler would result in immense repair costs. Deposits in the chemical recovery boiler lead to a significant reduction in steam and energy yield.

CF Decanter from GEA as a Game-Changer for Modern Chemical Recovery Boilers
Black liquor is the name for a residue left over from the chemical pulping process. This residue contains not only wood by-products, but also chemicals used in pulp production. The mixture is usually concentrated in an evaporator and then burned in the recovery boiler. The heat generated by this combustion is used to produce steam. The steam is used in the chemical pulping process and in paper production. The excess steam is converted into electrical energy in the turbines.

Ash treatment and ash leaching
Ash produced during combustion in the Chemical Recovery Boiler contains high levels of potassium and chloride. These chlorides increase the risk of corrosion in many parts of the recovery boiler. The potassium also makes the ash sticky, causing it to adhere to internal boiler surfaces and significantly reducing energy efficiency. These problems can be avoided by using appropriate ash treatment systems such as the one used at ITC with the GEA decanters.

Valmet
Valmet is the world's leading developer and supplier of process technologies, automation, and services for the pulp, paper, and energy industries. Valmet's technology offering includes pulp mills, tissue, board and paper production lines, and power plants for bioenergy production. Valmet's services and automation solutions improve the reliability and performance of customers' processes and increase the effective use of raw materials and energy. Valmet's headquarters are located in Espoo, Finland.

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ITC Paperboards and Specialty Papers Division
ITC Paperboards and Specialty Papers Division is one of the leading companies in the paper and board industry, providing solutions for a diverse cross-section of packaging and communication needs. With a focus on utilizing the latest technology, the company has become the largest manufacturer of packaging and graphic board in South Asia. ITC's Paper Board and Specialty Paper's Division has eleven machines at three locations with a production capacity of 800,000 TPA.