Technology overview: The company has designed a refrigerant system and heat exchanger in order to increase the maximum hot blast temperature up to 125℃ and also designed/realized a waste heat recovery cycle and independent hot blast system, applied to 125℃ refrigerant (R22, R407c) and four cycles. Their design and development include 125℃ evaporator and condenser as well as a pressure backup and control system to prevent high
pressure above 32kgf/㎠.
The company has developed an optimized compressor and expansion valve in addition to multi-step control and proportional control technologies depending on inlet-air temperatures. The newly developed automatic control system can save energy by 40% compared to a regular electric heater (95kWh capacity). The company’s automatic distribution control technology can control hot blast according to inlet-air temperatures. Furthermore, they have optimized a heat pump and auxiliary heater distribution control and improved the range of temperatures control and accuracy.
Also, their air volume control technology significantly enhances accuracy of air volume measurements across the range of temperatures. Air volume is controlled based on the average air volume measurement, taking into account air volume, wind velocity, temperatures, and specific gravity of air. The company has tested a 125℃ waste heat recovery hot-air drying unit and established a measurement platform (supported by KTL). Energy saving has been tested across the range of the highest heat blast temperatures and measurement platform has been designed. They have established measuring systems for waste heat recovery rates, auxiliary heater operation rates, and power consumption. The basic performance test and environmental test for the 125℃ waste heat recovery hot-air drying unit have been done and assessed (KTL) as well.
Industrialization: According to regular printing processes, eight or nine-color printing is applied to gravure while 4-color printing is applied to dry laminate printing, and the final drying process is applied to both. In this case, 10 units are needed for one production line of gravure and five units for dry laminate printing. Each dryer can control temperatures, air volume, and cooling cycle automatically. For gravure 10 units can be controlled in an integrated manner for batch operation of one production line.
In addition, a duct for exhaust gas, containing organic solvent, and a dust collector has been developed. Supplying heat blast optimized for the site by controlling temperatures and air volume could save energy by 70% in case of 200M/MIN gravure printing. ROI (return on investment) is estimated at 1.6 years, which proves high energy-saving effects.
Problem-solving in industrialization: Initially, there was a lack of data on energy saving rates, which can provide assurance to overseas buyers, but the results of tests on residual solvents and adhesive strength and energy-saving test by Armco Thailand proved 70% reduction for gravure printing and met the requirements of the internal standards and international environmental standards on residual solvents and adhesive strength. The data have been sent to the head office and the U.S. branch office of Armco with high prospects for being selected by the company to meet its energy reduction targets, and installation of an e-Saver has been under discussion since March 2015 with the U.S. branch office.
Armco is running over 40 printing factories worldwide, and replacing the existing 4,000 units with e-Saver is worth approximately KRW 80 billion. Armco Beijing, a joint stock company, has decided on the installation of e-Saver in April 2015 and shipment is under way as well.
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