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Transverse vibration of axially moving trapezoidal plates is investigated. The differential equation of transverse vibration for a axially moving trapezoidal plate is established by D'Alembert principle. The original trapezoid region can be replaced by regular square region by the medium parameter method for the convenience of calculation. A generalized complex eigenvalue equation is derived by a discrete method (the differential quadrature method). The complex frequency curve of trapezoidal plate is obtained by calculating the eigenvalue equation. The change of the complex frequencies of the axially moving trapezoidal plates with the dimensionless axially moving speed is analyzed. The effects of the aspect ratio and the trapezoidal angle on instability type of the trapezoidal plate are discussed under different boundary conditions. The results of numerical analysis show that there are two main instability types of axially moving trapezoidal plate: divergence and flutter. The modal orders of the two types of instability are also different, which is related to the trapezoidal angle, aspect ratio and boundary condition of the trapezoidal plate.

The drying section of paper machine is not only the major energy-consuming parts of the papermaking process, but also one of the main bottleneck restricting the speed, yield and paper quality. So the research on the drying section has attracted much attention at home and abroad. In view of the traditional steam dryer shortcomings, this paper first introduces two kinds of improvement measures —— the tubulator bar and the siphon which can improve the efficiency of the traditional steam dryer. With the development of the paper industry, domestic and international research on the new type of paper drying technology has achieved some success. Then, we analyse their working principle and characteristic, and conclude that multi-channel dryer has a broad research and application prospects.

This paper discusses the application of image processing methods in the Coal preparation detection system. The system uses a light source to illuminate the coal and coal gangue, and then captures images with a CCD camera. After that, those images are sent to analyze in the image processing module. The control system sets the jet valve to exclude gangue. For the image processing, the sample images are performed with the help of Matlab, by using the module of preprocessing, image segmentation and feature selection. After analyzing the grayscale histogram of the coal and gangue, the distinction between coal and coal gangue gray threshold are obtained. Finally, the control system compares the gray value and threshold to distinguish coal and gangue, and then excludes gangue to the transportation crawler.

In order to validate the model established in reference [1], a drying experimental study was conducted, and numerical simulation was carried out under the same environmental condition. The experiment and simulation results indicated that the fractal pore network model could explain the drying process of real porous media effectively, the drying curve of fractal models was more consistent with the real drying curve than that of regular models, and its moisture fields well reflected the drying kinetics characteristic of real porous media. There was no correlation between the pore fractal dimension and the drying time, and the simulation result of unsteady-state heat transfer was more consistent with a real drying process than that of steady-state heat transfer for the convective thermal drying.

In view of the fact that the two-dimensional square pore network model screened many microstructure features and transfer characteristics inside porous media, a fractal pore network model for unsteady drying process of natural porous body was developed on the base of fractal geometry theory and transport process principle, which took various factors into consideration, such as the liquid-phase flow, vapor-phase diffusion, temperature gradient, and pore microstructure characteristic.

This paper offers many advantages of smoke-free low-noise environment-friendly ground flare in comparison to traditional elevated flare in performance and technology, briefly summarizes the research status and development trends of ground flare at home and abroad. This paper makes a more detailed analysis and description focusing on the application of smoke-free low-noise environment-friendly ground flare in petrochemical industry. At the premise of safety, reliablity and environmental protection, how to study the new ground flare, in aspects such as dealing capability, combustion efficiency and control mode of flare burner, is the major direction of petrochemical waste gas treatment device in future development.

A pore network model for drying of grain materials was established on the base of pore network theory and transport process principle, and a corn drying experiment was conducted to verify the validity of this model. The experiment and simulation results indicated that this model could explain the drying process of grain materials well. There is a significant difference between the corn and pore vapor temperature, and it is unreasonable to confuse the two kinds of temperature. The particle size distribution has a great effect on the drying process. The higher the uneven degree of particle size distribution was, the slower the grain materials were dried and the more unbalanced the moisture distribution appeared.

In this paper, the authors explore the structure and operating mechanism of the energy- saving type multi-channel drying cylinder, which can be used in papermaking machine dryer section to effectively reduce the amount of condensate water, and tackle such problem as the water condensation in drying cylinder. This paper theoretically expatiates upon the heat transfer mechanism of the multi-channel drying cylinder of energy-saving type and verifies the theoretical results with numerical simulation approach, which proves that energy-saving type multi-channel drying cylinder can effectively improve the heat transfer efficiency, and increase the productivity of the papermaking machine while the drying cylinder is featured by high cost in manufacturing and non-uniformity in surface temperature because of its peculiarity of configuration, which need to be investigated and improved.

This paper introduces a high-speed image processing of embedded systems based on FPGA and DSP collaboration used in coal preparation detection technology. The system uses a modular design, including a real-time image acquisition module, DSP image processing module, and peripheral interface module. The image processing required doing the following arithmetic operations, including image smoothing to enhance, edge detection, region segmentation, gray-scale analysis, pattern recognition. After completion of the above algorithm, the system determines the image feature of coal and gangue, particularly their gray scale values and the center of gravity. By analysis of the characteristics of the image, the system identifies the gangue. The image processing is conducive to the follow-up to discharge refuse treatment.