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Pulse-width modulation (PWM), or pulse-duration modulation (PDM), is a modulation technique used to encode a message into a pulsing signal. Although this modulation technique can be used to encode information for transmission, its main use is to allow the control of the power supplied to electrical devices. This paper proposes the PWM control of the laboratory bell furnace with utilization of PI controller. The paper presents the PI control algorithm modified in order to regulate the power of furnace. The control ...

The coal processing industry uses a various technology for the process control. Various devices and control systems there can be implemented. With the support of automation, the production of final product can be more effective. Modern control system requires an advanced control algorithm on a several control levels (i.e. stabilization, optimization). The paper focuses to the process of coal combustion and coal gasification. Primarily two processes are examined i.e. underground coal gasification (UCG) and coking. ...

In paper the most important input variable revolutions (rpm) of drilling tool is analyzed by utilization of Shewhart control chart. The revolutions of drilling tools have a double meaning, in term of the performance and economics. Two measured variable namely pressure force F (N) and speed of rock drilling v (mm.s-1) closely related with revolutions. In general, control charts are used as a proven means to improve the qualitative parameters of production and in the prevention of errors, discrepancies in production...

In the paper is described system of indirect measurement of melt temperature (SIMT) in the converter. The steelmaking process belongs to very complicated metallurgical processes. Steelworks annually make millions of tons quality steel for home and foreign market. Quality and quantity of produced steel is needed to rise so steelworks are able to compete in world in this part of an industry. One of the options how to raise the quality in this technological process is information about temperature during melt. Temper...

Underground coal gasification (UCG) is an industrial process that provides an alternative to conventional underground mining at coal seams that are located especially deep underground. This process converts coal into product gas (syngas). In this contribution, a proposal of the monitoring system of the underground coal gasification process is presented. The task of the monitoring system is shown indirect measured values from UCG process as two-dimensional temperature field of gasified coal seam. The two-dimensiona...

The contribution shows the problems of unde rground coal gasification. Currently, this topic is timely, seeing that many coal deposits can not mine through traditional mining methods. Through underground gasification can be obtained from these deposits so- called synthetic gas - syngas, which can be conve rted into electricity or used in industry and households as fuel. Underground gasification technology has been verified in laboratory conditions for several experiments. Experiments differed fr om one by ways of ...