초록 ▼

A furnace system includes a furnace and a furnace monitoring and control system having a gas analyzer for analyzing the composition of furnace off-gases, and a sampling tube or probe used to obtain a high temperature off-gas sample for delivery to the gas analyzer. Gas samples are drawn to the gas a

A furnace system includes a furnace and a furnace monitoring and control system having a gas analyzer for analyzing the composition of furnace off-gases, and a sampling tube or probe used to obtain a high temperature off-gas sample for delivery to the gas analyzer. Gas samples are drawn to the gas analyzer, via the probe, by a vacuum. The probe is formed as a generally cylindrical or polygonally shaped hollow tube, which when mounted in the system defines a generally vertically extending elongated gas passage along which sample gas is drawn, and whereby sample gas flow in the passage is in a generally vertical direction. The probe is provided with upper and lower openings which extend into the gas passage. The lower opening is provided in gaseous communication with the furnace off-gas stream and is formed so as to permit the substantially unhindered movement of particulate matter, such as dust, downwardly along the gas passage and outwardly through the open bottom end. The upper opening is provided in gaseous communication with the gas analyzer, and a filter is removably positioned across the upper opening to prevent dust and other particulate matter entrained in the sample off-gas from moving through the upper opening and into the gas analyzer. To cool the sample gas and prolong the filter life, part of the probe is provided with a double sidewall construction so as to define a partitioned annular chamber extending about at least part of the gas passage along which cooling fluid may move.

대표청구항 ▼

[ We claim:] [1.] An apparatus for sampling high temperature furnace off-gases from an off-gas stream and for delivering sample gas substantially free of particulate matter to gas analyzer means, the apparatus including,an elongated sampling probe, gas conduit means providing gaseous communication b

[ We claim:] [1.] An apparatus for sampling high temperature furnace off-gases from an off-gas stream and for delivering sample gas substantially free of particulate matter to gas analyzer means, the apparatus including,an elongated sampling probe, gas conduit means providing gaseous communication between said probe and said gas analyzer means and means for vacuum drawing said sample gas to said gas analyzer via said conduit means,the sampling probe including,an inner sidewall substantially defining an elongated, vertically extending substantially cylindrical sample gas passage, said passage open to the stream at a lowermost open end,an upper opening spaced above said open end and permitting gas flow between said passage and said conduit means,an outer sidewall spaced radially outwardly about at least part of said inner sidewall and defining a generally annular chamber therebetween,upper chamber wall means extending radially from said inner sidewall to said outer sidewall,lower chamber wall means extending radially from said inner sidewall to said outer sidewall and closing a lowermost end of the annular chamber,first and second partition means, each extending across said annular chamber between said inner sidewall and said outer sidewall, and being spaced from said lower wall means to divide the annular chamber into at least two fluid communicating coolant fluid channels for cooling said sample gas in said passage,means for introducing coolant fluid into said coolant fluid channels,filter means disposed in said cylindrical sample gas passage said filter means provided across said upper opening for filtering particulate matter from said sample gas as said sample gas is drawn through said upper opening,the lowermost open end substantially unobstructing downward movement of said particulate matter filtered from said sample gas, outwardly from said gas passage. [9.] An apparatus for obtaining a high temperature gas sample from an electric arc furnace off-gas stream and for delivering said sample to a gas analyzer, the apparatus comprising,a hollow sampling probe defining a vertically oriented elongated cylindrical sample gas passage, said passage opening downwardly at its lowermost end into a bottom opening of said off-gas stream, said probe including an upper opening through which said sample gas moves from said gas passage to the gas analyzer,vacuum means in gaseous communication with said upper opening for drawing said sample from said off-gas stream into said passage via said bottom end opening and outwardly from said passage through said upper opening to said gas analyzer,filter means disposed in said cylindrical sample gas passage said filter means provided across said upper opening for filtering particulate matter from said sample as said sample is drawn through said upper opening,vent port means for venting backflow gas directly into said gas passage said vent port means spaced towards said upper opening andbackflow gas supply means selectively operable to supply backflow gas to said passage through said vent port means and through the filter means via the upper opening, whereby said backflow gas supplied to said passage flows downwardly along said passage to dislodge particulate matter retained on said inner sidewall. An apparatus as claimed in claim 9, wherein said filter means comprises a filter body which includes,a hollow perforated sleeve support sized for fitted insertion through said upper opening,a high temperature fibre filter sleeve sized for placement over said sleeve support, andretaining means for retaining said filter sleeve substantially over said sleeve support. An apparatus as claimed in claim 9, wherein said upper opening is provided through a top portion of said probe, said upper opening comprises a threaded opening formed through said top portion, and said filter means includes threaded coupling means for releasably threadedly coupling said filter means in said threaded opening. An apparatus as claimed in claim 9 wherein said backflow gas supply means is operable to independently supply said backflow gas to said vent port means and through said filter means. An apparatus as claimed in claim 9, wherein said tube further comprises an inner sidewall substantially defining said cylindrical passage,an outer sidewall spaced radially outwardly about at least part of said inner sidewall and defining a generally annular chamber therebetween,upper and lower wall means, each extending radially from said inner sidewall to said outer sidewall, said upper and lower wall means closing a respective upper and lower end portion of said annular chamber,first and second partition means, each extending across said annular chamber between said inner sidewall and side outer sidewall, and being spaced from said lower wall means to divide the annular chamber into at least two fluid communicating coolant fluid channels for cooling said sample gas in said passage, andmeans for introducing coolant fluid into said coolant fluid channels. An apparatus as claimed in claim 13, wherein said bottom opening has a radial diameter equal to that of said gas passage so as to permit substantially unhindered movement of said particulate matter downwardly from said passage. An apparatus as claimed in claim 14, wherein said backflow gas supply means comprises a source of gas at a pressure above pressure in said passage, said apparatus further including conduit means providing selective gaseous communication between the upper opening and said vacuum means, andconduit valve means operable to selectively connect the upper opening to either:(a) said vacuum means, whereby said vacuum means draws gas outwardly from said passage through said filter means via said upper opening, or(b) said source of gas, whereby the conduit means permits gas from the source of gas to backflow into the passage and through at least one of the filter means via the upper opening and the vent port means. Use of an apparatus for sampling and analyzing high temperature furnace off-gases from an off-gas stream and for controlling furnace operations in response to the sample analysis,the apparatus comprising,gas analyzer means for analyzing said sample gas, an elongated sampling probe, and gas conduit means providing gaseous communication between said probe and said gas analyzer means and vacuum means for drawing said sample gas to said gas analyzer via said conduit means,the sampling probe comprising,an inner sidewall substantially defining an elongated substantially cylindrical sample gas passage, said passage open to the stream at a lowermost open end,an upper opening spaced above said open end and permitting gas flow between said passage and said conduit means,an outer sidewall spaced radially outwardly about at least part of said inner sidewall and defining a generally annular chamber therebetween,upper chamber wall means extending radially from said inner sidewall to said outer sidewall,lower chamber wall means extending radially from said inner sidewall to said outer sidewall and sealing a lowermost end of the annular chamber,first and second partition means, each extending across said annular chamber between said inner sidewall and said outer sidewall, and being spaced from said lower wall means to divide the annular chamber into at least two fluid communicating coolant fluid channels for cooling said sample gas in said passage,means for introducing coolant fluid into said coolant fluid channels,filter means disposed in said cylindrical sample gas passage, said filter means provided across said upper opening for filtering particulate matter from said sample gas as said sample gas is drawn through said upper opening, rein the lowermost open end substantially unobstructs downward movement of said particulate matter filtered from said sample gas, outwardly from said gas passage, andbackflow gas supply means selectively operable to supply backflow gas flow downwardly along said gas passage, rein while said gas passage is in a substantially vertical orientation sampling of said off-gas is performed by the steps of:(a) activating said vacuum means for drawing a sample to said gas analyzer via said gas passage to draw an off-gas sample into said gas passage via the lowermost open end,(b) simultaneously while drawing said sample, circulating coolant fluid through said coolant channels to cool said sample as its moves along the passage, and(c) periodically interrupting the drawing of said off-gas sample and activating said backflow gas supply means to provide backflow gas along said gas passage to assist in dislodging particulate matter therein. Use of an apparatus as claimed in claim 16, wherein said apparatus further includes furnace control means in electronic communication with said gas analyzer means, said furnace control means including furnace control signal output means for outputting furnace controlling signals and data storage means,said method including the further steps of:(d) storing first data representative of at least one furnace heat in said data storage means,(e) comparing sample data from said gas sample to said first data; and(f) outputting said signals from said furnace control signal output means to adjust furnace operations in response to said comparing step. Use of an apparatus as claimed in claim 17, wherein said first data comprises a normalized heat profile. Use of an apparatus as claimed in claim 16, wherein said coolant fluid is pumped through the coolant channels at a rate of between about 40 to 80 gallons per minute.