Largest cement plant in Qinghai Province excels with Chinese version of Emerson's DeltaV digital automation system

The Chinese-language version of Emerson Process Management's DeltaV digital automation system achieved its first anniversary in successfully controlling all aspects of a Portland cement production line with a capacity of 2,000 metric tons per day.

The Qinghai Cement Company plant is located in Datong, 30 kilometers north of Xining, the capital of Qinghai province. With 700 employees and a 50-hectare site, this is one of the larger cement factories in western China. It is the largest in Qinghai province, which occupies the northern third of the Tibetan plateau.

"It's no wonder that the DeltaV system has become so widely recognized as an industry leader in process automation," said Sun Duo Kang, chairman of Qinghai Cement Company and general manager of the plant. "And now we have proven that it excels in the unique requirements of a modern cement plant in all conditions and seasons of the year."

"Bear in mind, this is a really tough environment for electronics," added Sun. "I'm talking about 2,400 meters above sea level, climate extremes, very dusty conditions, frequent power upsets, strong electromagnetic interference, and so forth. But it's no trouble for the DeltaV system."

Li Xue Feng, assistant superintendent of instrument and electrical engineering, cited some specific advantages of the DeltaV system: high reliability, quick response to engineers and operators, friendly user interfaces that are easy to learn, an unusually wide selection of powerful control strategies, and ease of configuration and maintenance by the plant's own people. Moreover, all text in the system is Chinese rather than English, thus expanding the DeltaV system's applicability in that country.

China is the world's leading producer of Portland cement, accounting for more than a third of global output. Qinghai Cement's plant makes as much as 3,500 metric tons per day, turning out nine different products used in dams, roads, and bridges in this rapidly developing country.

"We wanted to use the latest technology in this big new line to increase our product varieties and improve product quality and operating efficiency," explained Superintendent Li. "The DeltaV system has been a major part of our success in that effort."

Li also expressed appreciation for the openness of DeltaV automation. The system is based on open, interoperable industry standards including the Chinese-language version of the Microsoft Windows operating systems, Ethernet, and TCP/IP Internet protocol.

Finally, Mr. Li noted that the DeltaV system facilitates integration with other systems such as dedicated controllers built into some processing equipment, and that it easily accommodates inputs and outputs of nearly any kind.

In evaluating the DeltaV system's performance for its first year, Qinghai Cement's main point of comparison was a Honeywell Micro TDC 3000 distributed control system or DCS. That network controls the plant's only other production line, which started up in 1998 with a capacity of 1,500 metric tons per day.

Another reference point was a 700-tons-per-day facility built in 1977 that was replaced by the new 2,000-ton line. Its controls were based on electromechanical relays.

Relays and their modern counterparts, programmable logic controllers or PLCs, are oriented toward the discrete or on-off functions that predominate in cement plants. By contrast, distributed control systems such as the Micro TDC 3000 at Qinghai Cement are oriented instead toward continuous control functions that are common in chemical plants but are also crucial for cement plants.

The DeltaV system, in turn, is a newer system that efficiently embraces processes that depend heavily on both discrete and continuous control functions. Cement plants are a classic example. More important, the DeltaV system facilitates implementing the latest generation of digital automation architecture, represented by Emerson's PlantWeb architecture.

In PlantWeb, control intelligence is largely dispersed to computer-based field instruments such as transmitters and control valves, rather than being concentrated solely in distributed controllers of a DCS or PLC network. These "intelligent" instruments communicate by efficient digital methods that include FOUNDATION fieldbus and HART protocol.

Advantages of instrument intelligence that is leveraged by PlantWeb architecture include faster commissioning, self-calibration, self-diagnosis, and automated asset management-all extremely valuable in cement plants. At Qinghai Cement, about 100 of the field instruments connected to the DeltaV system are intelligent ones supporting PlantWeb — including Rosemount pressure and temperature transmitters using HART industry standard communications.

Qinghai Cement is owned by Qinghai Investment and Holding Company, an enterprise of the provincial government and China's Gintian Industry Group.

The project design was supplied by Chendu Industrial Design Institute of Building Materials in the city of Chendu, Sichuan Province. Instruments and controls were installed by Suzhou Installation Engineering Company.

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