Industrial Process Monitoring And Imaging (Patent Application: Chevron U.S.A./Silixia)

CATEGORY: ASSET INTEGRITY-DELAYED COKING 
Industrial Process Monitoring And Imaging (Patent Application: Chevron U.S.A./Silixia)
United States Patent Application 20150247751
September 3, 2015
Assignee: SILIXA LIMITED
Assignee: CHEVRON U.S.A.
Abstract
Exemplary embodiments include an apparatus for imaging a volume of material contained inside a vessel. The apparatus includes a plurality of synchronized acoustic sensors positioned at a periphery of an inner volume of the vessel. A processor combines the outputs of the acoustic sensors to identify at least one ambient noise source of the industrial process generating a noise field that illuminates an internal volume of the vessel and to provide an image of the material by temporal and spatial coherent processing of the transmission and reflection of the noise field generated by the noise source.
BACKGROUND
[0002] Acoustic detection has been proposed for condition monitoring in industrial process applications. In these conventional applications, a number of acoustic sensors can be placed on the outside wall of the vessel to detect acoustic emission generated by different components. The acoustic emissions can be processed to generate an acoustic profile, which may be used to detect the existence of an acoustic anomaly, caused by a leak, change in process node, change in the phase of a component, or other characteristics of the industrial process as desired. These applications have limitations, however, in an ability to generate images of the internal volume of the vessel from the acoustic emissions detected by the sensors. Image generation can also be constrained by the environmental and structural characteristic of the industrial process and vessel. In some configurations, the vessel can include a thick outer wall, which greatly limits and/or prevents the monitoring of the process inside the vessel.
[0003] For example a coking operation is a refining technique for generating oil and petroleum products from non-uniform residual feedstocks. In a delayed coking operation, a residual oil feed is heated in a furnace with multiple parallel passes to its thermal cracking temperature. The heating cracks the heavy, long chain hydrocarbon molecules of the residual oil into coker gas oil and petroleum coke.
[0004] The coking process can present a number of undesired conditions. One such condition involves the formation of hot-spots. A hot-spot is typically an egg-shaped volume of coke on the order of a few feet in diameter, which has a hard, non-porous shell. The hot-spot can retain heat because water does not penetrate the shell during a quenching process. During a quenching process, water is introduced into the vessel to cool the coke material. That is, when the coking vessel is substantially filled with solidified coke, the vessel is steamed to further reduce hydrocarbon content of the petroleum coke. In a next step, the material in the vessel is cooled by quenching with water. The top and bottom heads of the coke drum are removed, and the solid petroleum coke is then cut from the coke drum with a high pressure water drill. When the water drill hits a hot-spot, thermal energy can be released through the opening at the top of the vessel.
[0005] U.S. Pat. No. 5,517,537 A describes an acoustic leak detection system that maps acoustic noise in a three-dimensional acoustic noise field for leak detection. Acoustic sensors are coupled to the external vessel walls of a steam generator and chemical sensors are placed inside the vessel to monitor the hydrogen content of liquid sodium and a cover gas. The externally mounted sensors monitor the acoustic pressure within the steam generator vessel by measuring the wall motion resulting from the impact of acoustic pressure waves. The system extracts acoustic pressure waves that result from a leak (e.g., due to a sodium-water reaction) inside the vessel. This detection scheme is limited to locating a leak in the absence of large background noise and cannot be used to image an internal volume of the vessel.
[0006] US 2007/0038393 A1 discloses a system that proposes monitoring the status of a cutting tool and the level of coke in a drum during a delayed decoker unit operation. Plural sensors are coupled in vertical and horizontal orientations to a component of the coker unit, such as outside the drum, on the drill stem, a fluid line, and/or a fluid pump. The data collected by the sensors are output the data to a computer. When the drum is off-line, the drill is in boring mode, and water is ejected from high pressure nozzles to cut a bore hole through solid coke in the drum, each sensor measures vibrations produced because of the process. The collected data from each sensor can be amplified, calibrated, and/or transformed using a Fast Fourier Transform (FFT). The resulting wave can be used to create a fingerprint of the boring process, and when the coking process is operational, the data collected by each sensor can be analyzed to monitor the cutting tool and/or determine the mode, such as ramping, cutting, and drilling, for example. While this system can monitor the coke levels inside a coke drum and detect a position of the drill, it does also not provide a capability to image the coking process within the drum.
[0007] Each of the prior art disclosures are hereby incorporated by reference in their entirety.
[0008] Given the known art there is a need for a system, method, and arrangement that can image the inner volume of a vessel associated with an industrial process and detect the physical and chemical features of a medium in the vessel, which is acted on by the industrial process.
SUMMARY
[0009] An exemplary embodiment of the present disclosure is directed to an apparatus for imaging a volume of material contained inside an enclosure. The apparatus includes a plurality of synchronized acoustic sensors positioned at a periphery of an inner volume of the enclosure, to sense acoustic energy emanating from the material in the enclosure during an industrial. A processor that combines an output of each of the acoustic sensor to identify at least one ambient noise source generating a noise field that illuminates an inner volume of the enclosure and to produce image data of the material by temporal and spatial coherent processing of the transmission and reflection of the noise field generated by the noise source.
[0010] Another exemplary embodiment is directed to a method of imaging material in an inner volume of a vessel using velocity and/or spatial filtering techniques to reduce the surface acoustic effect of the vessel wall and measure more effectively the acoustic energy emitted within the vessel. The method includes detecting acoustic signals generated by the industrial process through a plurality of synchronized sensors positioned at a periphery of an inner volume of the enclosure, the outputs of which are combined to form an acoustic image of the material inside the vessel. At least one noise source generating a noise field that illuminates the volume of a material inside the vessel, and an acoustic image of the material is generated by temporal and spatial coherent processing of the transmission and reflection of the noise field generated by the noise source.
[0011] A further exemplary embodiment is directed to a method of level detection in an enclosure. The method includes detecting characteristic acoustic signals of the industrial process through a plurality of time-synchronized sensors disposed about an axis of the enclosure. A time of flight of one of the detected acoustic signals is measured at each one of the plurality of sensors, and the time of flight of the detected acoustic signals measured at each one of the plurality of sensors is analyzed to determine a fluid level in the enclosure.
[0012] Another exemplary embodiment is directed to a method of detecting an object in an enclosure. The method comprises detecting characteristic acoustic signals of an industrial process acting on a material within the enclosure through a plurality of time-synchronized sensors disposed about a periphery of an inner volume of the enclosure, and measuring a time of flight of one of the detected acoustic signals at each one of the plurality of sensors. The time of flight of the measured acoustic signals at each of the plurality of sensors is analyzed to determine a size and location of an object in the material acted by the industrial process in the enclosure.
[0013] Additionally, an exemplary embodiment is directed to a computer readable medium containing a program which when compiled on a computer causes the computer to execute a process of imaging material in an inner volume of an enclosure of an industrial process. The method performed by the computer includes synchronizing acoustic signals received from a plurality of sensors disposed at a periphery of the inner volume of the enclosure, and generating a plurality of two-dimensional images of the inner volume of the enclosure based on the synchronized acoustic signals. The synchronized acoustic signals are associated with characteristics of the material in the industrial process. The method also includes identifying at least one source of the synchronized signals in the enclosure, and stacking the plurality of two-dimensional images to generate a three-dimensional image of the inner volume of the enclosure.
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