Low cost total reduced sulfur analysis system
OwnerRobert L. Tomlininventor
Life of this patent
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Abstract
A system and apparatus for analyzing stack gas for total reduced sulfur. The gas is withdrawn from a stack through a probe, filtered and regulated to a known temperature. The gas is then passed through a scrubbing column to remove sulfur dioxide and split into first and second portions. The first portion is oxidized to covert total reduced sulfur compounds to SO2, and the gas is then passed to an electrochemical sensor for SO2 which is maintained at a temperature at least equal to the temperature of the regulated gas. The second portion of the scrubbed gas is passed through an electrochemical sensor for oxygen which is maintained at substantially the same temperature as the sensor for SO2.
Claims20
A method for analyzing gas flowing through a stack for total reduced sulfur, comprising the steps of:
- a) withdrawing at a rate of about 10-200 cc/min, a portion of the gas flowing through the stack;
- b) filtering the withdrawn gas;
- c) passing the filtered gas to a first zone regulated to a temperature T1 and regulating the temperature of the filtered gas to T1 by passing through a tube regulated to T1 by a heat exchanger, the filtered gas having a relative humidity of 50-100% at T1;
- d) splitting the temperature regulated gas into first and second portions;
- e) scrubbing SO2 from the first portion within said first zone at temperature T1 by passing through a column containing SO2 scrubber media within said first zone and at temperature T1;
- f) subjecting the first portion of the scrubbed gas to oxidizing conditions to convert total reduced sulfur compounds therein to SO2;
- g) passing the converted gas to a second zone controlled to a temperature T2 which is greater than or equal to T1, such that the relative humidity of the converted gas in the second zone is less than 100%, and analyzing the converted gas by means of a first electrochemical sensor maintained at temperature T2;
- h) passing the second portion of the scrubbed gas to said second zone at temperature T2, the relative humidity of the second portion in the second zone being less than 100%, and analyzing the second portion for oxygen by means of a second electrochemical sensor maintained at temperature T2;
- and
- i) determining total reduced sulfur in the gas, said steps b), c), d), e), f), g) and h) taking place within a common instrument housing.
A system for analyzing stack gas comprising a common instrument housing containing therein:
- a) a probe extending from the housing into a stack for withdrawing a portion of the stack gas therefrom;
- b) a filter for removing particulate matter from the withdrawn stack gas operatively connected to said probe;
- c) first heat exchanger means operating to create a first zone regulated to temperature T1, said first zone containing therein a temperature regulated tube operatively connected to said filter, and regulating the temperature of the filtered stack gas, and means for draining water condensed from the temperature regulated gas;
- d) gas splitting means operatively connected to said temperature regulated tube for splitting the scrubbed gas into first and second portions;
- e) a scrubber means operatively connected to said gas splitting means for scrubbing SO2 from the first portion;
- f) oxidizer means operatively connected to said scrubber means for oxidizing total reduced sulfur compounds in a first gas portion;
- and
- g) second heat exchanger means operating to create a second zone regulated to a temperature T2, equal to or greater than T1, said second zone containing therein first and second electrochemical sensors regulated to temperature T2, said first electrochemical sensor being operatively connected to said oxidizer means for determining SO2 in the oxidized first gas portion, and said second electrochemical sensor being operatively connected to said splitting means for determining oxygen in the second gas portion.
Dependencies are inferred from the claim text.