Multi-point emission sampling system

Abstract

A system for collecting emission samples can include at least one probe having a plurality of elongate tubes, with each tube having an opening formed therein for positioning in an emission producing facility, such as in an outlet duct of a power generating facility. Each of the tubes can be of varying length with the tube openings at a terminal end of each tube, such that the tube openings reside at varying spaced-apart points when positioned in the outlet duct. Suction means, such as an aspirator, can be operatively connected to the plurality of tubes to suction gas in the facility through the openings and into the tubes, so that emissions carried in the suctioned gas are drawn into the plurality of tubes. A collection container can be operatively connected to the plurality of tubes and the suction means, such that the emissions are suctioned into the tubes and deposited into the collection container.

1 . An apparatus for collecting emission samples comprising:
 (a) a plurality of elongate tubes, each of the plurality of tubes including an opening formed therein for positioning in an emission producing facility, wherein the openings reside at varying spaced-apart points in the facility;   (b) suction means operatively connected to the plurality of tubes for suctioning gas in the facility through the openings and into the tubes, whereby emissions carried in the suctioned gas are drawn into at least one of the plurality of tubes; and   (c) a collection container operatively connected to the plurality of tubes and the suction means, whereby the emissions are suctioned into the tubes and deposited into the collection container.   
     
     
         2 . An apparatus according to  claim 1 , wherein the plurality of elongate tubes comprises at least four elongate tubes of varying length, and the opening of each tube is proximate a first terminal end of each respective tube, whereby the tube openings reside at varying depths when positioned in the facility. 
     
     
         3 . An apparatus according to  claim 1 , wherein the suction means comprises an aspirator operatively connected to the plurality of elongate tubes, wherein the aspirator suctions gas in the facility through the openings of the tubes and into the tubes. 
     
     
         4 . An apparatus according to  claim 3 , wherein the emissions producing facility comprises a fossil fuel burning boiler, and further comprising:
 (a) a pipe connected to the aspirator, wherein the pipe supplies compressed air from the boiler; and   (b) a valve operatively connected to the pipe and the aspirator for controlling the flow of the compressed air to the aspirator.   
     
     
         5 . An apparatus according to  claim 1 , wherein the emissions producing facility comprises a boiler having an outlet duct, and the tube openings are positioned in the outlet duct, and further wherein the gas in the facility comprises flue gas flowing through the outlet duct, and the tube openings are positioned to face the flue gas flowing through the outlet duct. 
     
     
         6 . An apparatus according to  claim 5 , wherein the elongate tubes are adapted for being positioned through a top surface of the outlet duct, and further wherein each elongate tube includes a nozzle residing substantially parallel to the outlet duct and defining the tube opening. 
     
     
         7 . An apparatus according to  claim 1 , further comprising means for measuring and controlling the flow of gas in each of the elongate tubes, whereby a substantially isokinetic sample of gas from the facility is collected in each tube. 
     
     
         8 . An apparatus according to  claim 7 , wherein a substantially equal portion of emissions is collected in each of the elongate tubes. 
     
     
         9 . An apparatus according to  claim 7 , wherein the means for measuring and controlling the flow of gas comprises an orifice and a control valve operatively connected to each of the elongate tubes. 
     
     
         10 . An apparatus according to  claim 1 , further comprising a plurality of thermocouples, wherein each of the thermocouples is operatively connected to one of the elongated tubes and positioned proximate the tube opening. 
     
     
         11 . An apparatus according to  claim 1 , further comprising a plurality of gas sampling ports, wherein each of the elongated tubes is in communication with one of the plurality of gas sample ports, whereby a sample of gas flowing through each of the tubes can be obtained. 
     
     
         12 . An apparatus according to  claim 1 , wherein the emissions comprise fly ash produced by combustion of fossil fuel. 
     
     
         13 . An apparatus according to  claim 12 , further comprising a cyclone separator having a first opening in communication with the plurality of elongate tubes, a second opening in communication with the suction means, and a third opening in communication with the collection container, the separator receiving the gas suctioned through the tubes and creating a cyclone of the suctioned gas, wherein the fly ash in the suctioned gas is deposited into the collection container. 
     
     
         14 . An apparatus according to  claim 13 , further comprising a filter operatively connected intermediate the suction means and the cyclone separator for capturing fly ash escaping the second opening of the cyclone separator while the suction means is operative, wherein the filter is positioned above the cyclone separator and the cyclone separator is positioned above the collection container, whereby the fly ash captured on the filter returns to the cyclone separator and the collection container when the suction means is inoperative. 
     
     
         15 . An apparatus according to  claim 13 , wherein the collection container is removably connected to the cyclone separator proximate the third opening, whereby fly ash collected in the collection container can be removed and transported. 
     
     
         16 . An apparatus for collecting samples of fly ash produced by combustion of fossil fuel in an emission producing facility comprising:
 (a) at least one probe comprising a plurality of elongate tubes, each of the plurality of tubes including an opening formed therein for positioning in the facility, and wherein the openings reside at varying points within the facility when positioned in the facility;   (b) an aspirator operatively connected to the plurality of tubes for suctioning flue gas in the facility through the openings and into the tubes, whereby fly ash present in the suctioned flue gas is drawn into at least one of the plurality of tubes; and   (c) a collection container operatively connected to the plurality of tubes and the aspirator, whereby the fly ash present in the suctioned flue gas is deposited into the collection container.   
     
     
         17 . An apparatus according to  claim 16 , wherein the emission producing facility includes an outlet duct, and further wherein the at least one probe comprises at least four elongate tubes of varying length, and the opening of each tube is proximate a first terminal end of each respective tube, whereby the tube openings of each probe reside at varying depths of the outlet duct when positioned in the outlet duct of the emission producing facility. 
     
     
         18 . An apparatus according to  claim 16 , wherein the at least one probe further comprises a cyclone separator having a first opening operatively connected to the plurality of elongate tubes, a second opening operatively connected to the aspirator, and a third opening operatively connected to the collection container, the cyclone separator receiving the flue gas suctioned through the tubes and creating a cyclone of the suctioned flue gas, wherein the fly ash in the suction gas is separated from the flue gas and deposited into the collection container. 
     
     
         19 . A method for collecting samples of fly ash emissions in an emission producing facility comprising the steps of:
 (a) providing an apparatus comprising:
 (i) a plurality of elongate tubes of varying length, each tube having an opening proximate a first terminal end of the tube, 
 (ii) an aspirator operatively connected to the plurality of tubes, and 
 (iii) a collection container operatively connected to the plurality of tubes and the aspirator; 
   (b) positioning at least a portion of each of the plurality of elongate tubes in the emission producing facility, such that the tube openings reside within the facility;   (c) activating the aspirator, and suctioning flue gas in the facility through the tube openings and into the plurality of tubes whereby the fly ash present in the suctioned flue gas is suctioned into the tubes;   (d) measuring and controlling flow of the flue gas in each of the elongate tubes, whereby a substantially isokinetic sample of flue gas from the facility is collected in each tube; and   (e) separating the fly ash from the suctioned flue gas.   
     
     
         20 . A method according to  claim 19 , further comprising the steps of:
 (a) depositing the fly ash into the collection container; and   (b) removing the collection container from the apparatus after the suctioned fly ash has been deposited into the collection container.