Industrial production process automation technology and safety control
since the world industrial revolution in the 19th century, industrial production processes have changed from simple to complex and from small to large. So far, there have been various industrial production processes, producing a variety of products to meet people's production needs. As a part of industrial production process, industrial process control system is also developing and improving
development of automatic instrument technology
in the process of industrial safety production, the variables that usually need to be measured and controlled include: temperature, pressure, flow, liquid level, weighing, electric quantity (current, voltage, power) and composition. The measurement and control of these variables with the continuous development of electronic technology, computer technology and measurement technology, although the basic measurement principle changes little, the signal replacement, display and control devices change very rapidly. In the recent 50 years, however, the new national standard GB 31604.1 (2) 015 clearly requires that the year of food simulants be selected according to the food or food type that the product is expected to contact. Industrial automation instruments range from the non-level installation of pneumatic instruments and dynamometers to electric instruments, from on-site local control to central control room control, from operation on the instrument panel to 9.1 random skill documents, including: operation with computer operation station (CRT), from analog signals to digital signals, etc, Its development and changes are amazing, as shown in Table 1-1
The 1950s is the era of electronic vacuum tubes. The scale of industrial production process is relatively small, and the instruments and control systems used are relatively simple and bulky. Pneumatic instruments are mostly used for measurement and control. Pneumatic signals of o.2-1.okgf/cm2 (3-15psi) are used as unified standard signals, and the recorder is an electronic tube type automatic balance recorder. The control system is a simple local devicein the 1960s, with the continuous expansion of industrial scale, especially the rapid development of petrochemical 2e212 industry, industrial production processes require centralized operation and control. During this period, semiconductor technology has developed rapidly. Automatic instruments began to use electric instruments, and electronic tubes were replaced by transistors. 6. Experimental operators should cherish instruments and equipment, check, scrub and maintain them frequently, and regularly clear the impurities in the oil tank. An electric type II instrument made of semi conductor discrete components was developed, with a unified signal standard of 0 ~ 10mA. The central instrument control room was used to operate, monitor and control the industrial production process. At the same time, computers began to be applied in the industrial production process to realize direct digital control (DDC)
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