Measurement of emission levels in a gas stream
OwnerKent S. Knaebelinventor
Life of this patent
Estimating the term…
Abstract
System and method for monitoring the level of a VOC or other vapor contaminant emitted in a gas stream or the like being vented at a specified pressure from an emission source. A medium of a bed of solid particles is provided within a vessel having an inlet and an outlet which is effective for separating the contaminant from the gas stream. The inlet pressure of the vessel is maintained at the specified pressure of the gas stream being vented from the emission source. The separated contaminants are concentrated in the medium which exhibits an increase in mass corresponding to the amount of the contaminant that was contained in the gas stream.
Claims34
A method for determining the amount of a volatile organic compound (VOC) or acid vapor contaminant emitted in a gas stream being vented at a specified pressure from an emission source, said method comprising the steps of:
- (a) providing a medium within a vessel having an inlet port coupled in fluid communication with said gas stream for receiving said gas stream at an inlet pressure, and an outlet port for exhausting the gas stream passed through the vessel, said medium being a bed of solid particles effective for separating substantially all of said contaminant from a defined amount of said gas stream;
- (b) determining an initial mass, m.sub.o, of said medium;
- (c) maintaining the inlet pressure of said vessel at said specified pressure of said gas stream being vented from the emission source;
- (d) passing through said medium during a time interval, t, said defined amount of said gas stream to concentrate said contaminant in said medium;
- (e) determining a final mass, mr, of said medium and said contaminant concentrated therein;
- and
- (f) determining the amount of said contaminant emitted per unit time in said gas stream according to the expression:
- ##EQU6## where m.sub.c is mass of said contaminant concentrated in said medium defined as the difference m.sub.f -m.sub.o.
A system for determining the amount of a volatile organic compound (VOC) or acid vapor contaminant emitted in a gas stream being vented at a specified pressure, said system comprising:
- a vessel having an inlet port coupled in fluid communication with said gas stream for receiving a defined amount thereof at an inlet pressure for passage through said vessel during a time interval, t, and an outlet port for exhausting the gas stream passed through said vessel;
- a medium of a bed of solid particles disposed in said vessel for separating substantially all of said contaminant from the defined amount of said gas stream passed through said vessel, said medium concentrating said contaminant therewithin and having an initial mass, m.sub.o, and a final mass, m.sub.f, corresponding to the mass of said medium and the mass of said contaminant concentrated therein;
- and
- a flow controller coupled in fluid communication with said gas stream for maintaining the inlet pressure of said vessel at said specified pressure of said gas stream being vented,
- wherein the amount of said contaminant emitted per unit time in said gas stream is determined according to the expression:
- ##EQU8## where m.sub.c is mass of said contaminant concentrated in said medium defined as the difference m.sub.f -m.sub.o.
A system for detecting contaminants in a gas emission comprising:
- a medium effective for separating at least a portion of said contaminants from said gas emission and having at least one surface in fluid communication with said gas emission for concentrating said contaminants therein;
- and
- a sensor assembly for sensing the change in mass of said medium in response to the concentration of said contaminants therein, said change in mass of said medium corresponding to the amount of said contaminants in said gas emission, and said sensor assembly comprising:
- a cantilevered member extending between a fixed end and a free end supporting said medium, said cantilevered member being deflectable intermediate said fixed end and said free end in response to the change in mass of said medium;
- and
- a sensor mounted on said cantilevered member, said sensor being responsive to the deflection of said cantilevered member for generating output signals proportional to the mass of said medium.
A system for detecting contaminants in a gas emission comprising:
- a medium effective for separating at least a portion of said contaminants from said gas emission and having at least one surface in fluid communication with said gas emission for concentrating said contaminants therein;
- and
- a sensor assembly for sensing the change in mass of said medium in response to the concentration of said contaminants therein, said change in mass of said medium corresponding to the amount of said contaminants in said gas emission, and said sensor assembly comprising:
- a diaphragm supporting said medium, said diaphragm having a fixed perimeter and a central portion within said perimeter, said central portion being deflectable in response to the change in mass of said medium;
- a first sensor element mounted to said central portion of said diaphragm for movement in correspondence with the deflection thereof in response to the change in mass of said medium;
- and
- a second sensor element fixed a predetermined distance from said first sensor element to confront the movement thereof, said first and said second sensor element being responsive to the distance therebetween for generating output signals proportional to the mass of said medium.
Dependencies are inferred from the claim text.