Understand the automation control of cement plantsDate: 2019-06-18 Views:
Domestic large-scale cement plants have applied cement production automation to the new dry process production line, and cement enterprises have become more and more demanding for automation technology. In this way, the application of automation technology in cement enterprises will continue to improve the overall industrial technology level. And it will be more mature in the future development.
1. Cement plant automatic control parameter type
(1) Switching quantity:motor opening and closing, interlocking, fault alarm signal valve opening signal; material level alarm signal. (2) Analog quantity: material level, flow rate, speed, current, temperature, pressure, valve position and composition.
The above parameters can be summarized as “safety parameters” and “productive parameters”. The “safety parameters” have important reference functions for the normal production and operation of the enterprise. It mainly refers to whether the equipment of the enterprise is safely operated and reduces non- It has a positive effect on the planned shutdown, such as the temperature of the kiln trap and the temperature of the bearing bush. The “productive parameter” is a parameter directly related to the production of the enterprise, and plays a guiding role in the operation and production of the enterprise, such as The temperature and pressure of the outlet of the cyclone tube, and some parameters have the above two parameters, such as the CO content of the dust collection at the kiln end. By dividing and studying these parameters, the normal production operation of the enterprise can be effectively guaranteed. When a production accident or a safety risk occurs, the alarm point can be issued in time to avoid the loss of the enterprise.
2. Classification of automatic control systems in cement plants
According to the relevant production process and characteristics of the enterprise, the production line of the enterprise is usually divided into four centralized control systems: raw material preparation system, raw material preparation system, cement grinding system and firing system. The specific division is as follows:
(1) Raw material preparation system:from the raw material ingredient library through the raw material grinding to the top of the raw material storage;
(2) Raw material preparation system:including limestone crushing and raw material storage;
(3) Cement grinding system:the material is discharged from the bottom of the clinker, transported by cement grinding and cement to the cement storage bottom of cement topping cement packaging system to cement packaging, including bulk storage;
(4) Firing system:the raw material is homogenized and the bottom of the warehouse is discharged. After the kiln tail and the exhaust gas are treated, the feeding system, the rotary kiln and the clinker are broken to the top of the clinker storage, and the coal powder preparation system is also included.
Fieldbus control is the hottest research object in automation control in recent years. With the continuous advancement of science and technology, fieldbus control will gradually replace the existing DCS system and promote the development of cement industry. Fieldbus is a computer network. It is a fully digital, two-way, multi-station communication system between field instrumentation and control room systems.