Studies and research concerning BNFP: automated on-line calibration of differential pressure transmitters

1981 ◽  
Author(s):  
J M Crawford
2013 ◽  
Vol 291-294 ◽  
pp. 1874-1879 ◽  
Author(s):  
Xiao Gang Xu ◽  
Song Ling Wang ◽  
Jin Lian Liu ◽  
Fei Li ◽  
Hui Jie Wang

The running state of the fan has significant influence on the safety and economy of the power plant unit, so it is necessary to monitor the fan performance and running state in real time. According to the basic theory of the fan, there is a stable, good nonlinear mapping relation between the inlet pressure difference and flow, which can be utilized to monitor the flow of the fan. Thus, the fan differential pressure - flow curve model is established by the optimized BP neural network and the modified Support Vector Machine (SVM). The fitting error shows that the improved SVM model is better. Finally, the on-line fan monitoring system software is established by using Visual Basic (VB) language and Matlab programming based on the improved SVM fan differential pressure - flow curve model, which can accurately monitor the fan operation.


Author(s):  
Jeff Ladwig ◽  
Robin Linton

Like many coal-fired power plants today, the waste-to-energy (WTE) industry is faced with a number of challenges including the need to maximize plant output, lower outlet emissions and increase plant efficiencies. Within WTE, there’s also been a move from reverse-air baghouses to pulse-jet collectors due to lower initial capital costs and the ability to operate pulse-jet collectors at higher air-to-cloth ratios (3–4:1), allowing for a smaller housing footprint. However, the majority of today’s pulse-jet collectors utilize an off-line cleaning mode where modules are taken out of service and pulsed to lower the differential pressure. There are inherent advantages in switching from an off-line cleaning mode to an on-line cleaning mode. This paper discusses the idea of using the fabric filter as a damper and stabilizing draft through the baghouse and boiler. It also outlines the use of pleated filter element (PFE) technology to address increased production concerns, and the need for lower outlet emissions.


Author(s):  
Matthew A. Eaton

Waste-to-energy boiler fire-side fouling is a major operational issue for many facilities, including the Commerce Refuse-to-Energy Facility. The Commerce Refuse-to-Energy Facility is a 350 ton per day, mass burn waterwall facility that began operation in 1987. Fouling occurs throughout the convection sections with the highest differential pressure occurring across the generating bank. Flue gas differential pressures and temperatures have been tracked and analyzed at the facility for approximately ten years during various operating conditions. It has been determined that the rate of increase of the differential pressure across the generating bank is correlated with flue gas temperature and the extent of fouling. Several different cleaning methods have been used to clear the convection zone of ash deposits, including off-line hydroblasting, on-line hydroblasting, on-line explosives cleaning, sootblowers and sonic horns. Better understanding of the fouling trends and evaluation of cleaning methods has led the facility to use a combination of on-line hydroblasting and explosives cleaning and off-line hydroblasting. The facility is now able to operate one year between planned outages, compared to ten weeks during the initial operation of the facility. Additional savings have also been achieved by reducing induced draft fan load, and possibly a reduction in tube wastage.


Author(s):  
William Krakow

In the past few years on-line digital television frame store devices coupled to computers have been employed to attempt to measure the microscope parameters of defocus and astigmatism. The ultimate goal of such tasks is to fully adjust the operating parameters of the microscope and obtain an optimum image for viewing in terms of its information content. The initial approach to this problem, for high resolution TEM imaging, was to obtain the power spectrum from the Fourier transform of an image, find the contrast transfer function oscillation maxima, and subsequently correct the image. This technique requires a fast computer, a direct memory access device and even an array processor to accomplish these tasks on limited size arrays in a few seconds per image. It is not clear that the power spectrum could be used for more than defocus correction since the correction of astigmatism is a formidable problem of pattern recognition.


Author(s):  
A.M.H. Schepman ◽  
J.A.P. van der Voort ◽  
J.E. Mellema

A Scanning Transmission Electron Microscope (STEM) was coupled to a small computer. The system (see Fig. 1) has been built using a Philips EM400, equipped with a scanning attachment and a DEC PDP11/34 computer with 34K memory. The gun (Fig. 2) consists of a continuously renewed tip of radius 0.2 to 0.4 μm of a tungsten wire heated just below its melting point by a focussed laser beam (1). On-line operation procedures were developped aiming at the reduction of the amount of radiation of the specimen area of interest, while selecting the various imaging parameters and upon registration of the information content. Whereas the theoretical limiting spot size is 0.75 nm (2), routine resolution checks showed minimum distances in the order 1.2 to 1.5 nm between corresponding intensity maxima in successive scans. This value is sufficient for structural studies of regular biological material to test the performance of STEM over high resolution CTEM.


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