Waste gas purification apparatus and method therefor

Abstract

A waste gas purification apparatus comprises a cooling unit including a cooling chamber containing a cooling fluid and a waste gas transmission pipe passing through the cooling chamber and immersing in the cooling fluid, which is used to cool the waste gas input into the waste gas transmission pipe; a dust eliminating unit provided at the downstream side of the cooling unit and used to eliminate harmful substances and dust contained in the waste gas; an absorbing unit provided at the downstream side of the dust eliminating unit and containing an absorbing fluid, which is used to eliminate carbon dioxide and sulfide contained in the waste gas by mean of the reaction between the absorbing fluid and the carbon dioxide and sulfide, in which the carbon dioxide and sulfide react with the absorbing fluid to generate precipitates; and a cleaning unit provided at the downstream side of the absorbing unit and containing a cleaning fluid, which is used to eliminate harmful substances and dust remained in the waste gas. A waste gas purification method is also provided.

1 . A waste gas purification apparatus comprising:
 a cooling unit including a cooling chamber containing a cooling fluid and a waste gas transmission pipe passing through the cooling chamber and immersing in the cooling fluid, which is used to cool the waste gas input into the waste gas transmission pipe;   a dust eliminating unit provided at the downstream side of the cooling unit and used to eliminate harmful substances and dust contained in the waste gas;   an absorbing unit provided at the downstream side of the dust eliminating unit and containing an absorbing fluid, which is used to eliminate carbon dioxide and sulfide contained in the waste gas by mean of the reaction between the absorbing fluid and the carbon dioxide and sulfide, in which the carbon dioxide and sulfide react with the absorbing fluid to generate precipitates; and   a cleaning unit provided at the downstream side of the absorbing unit and containing a cleaning fluid, which is used to eliminate harmful substances and dust remained in the waste gas.   
   
   
       2 . The waste gas purification apparatus according to  claim 1 , wherein the cooling chamber is provided with a cooling fluid level adjustment device for adjusting the level of the cooling fluid contained in the cooling chamber, to immerse the waste gas transmission pipe in the cooling fluid all the time. 
   
   
       3 . The waste gas purification apparatus according to  claim 1 , wherein the cooling chamber is a hermetic container and provided with a steam recycling device for recycling the steam generated by the cooling fluid during the course of cooling the waste gas. 
   
   
       4 . The waste gas purification apparatus according to  claim 2 , wherein the cooling chamber is a hermetic container and provided with a steam recycling device for recycling the steam generated by the cooling fluid during the course of cooling the waste gas. 
   
   
       5 . The waste gas purification apparatus according to  claim 3 , wherein the cooling chamber is separated into a plurality of compartments by a plurality of spacers, and a steam communication port is provided at the upper part of each spacer to enable the steam to communicate between adjacent compartments, and a cooling fluid communication port is provided at the lower part of each spacer, to enable the cooling fluid to communicate between adjacent compartments. 
   
   
       6 . The waste gas purification apparatus according to  claim 4 , wherein the cooling chamber is separated into a plurality of compartments by a plurality of spacers, and a steam communication port is provided at the upper part of each spacer to enable the steam to communicate between adjacent compartments, and a cooling fluid communication port is provided at the lower part of each spacer, to enable the cooling fluid to communicate between adjacent compartments. 
   
   
       7 . The waste gas purification apparatus according to  claim 3 , wherein the cooling chamber is separated into a plurality of compartments by a plurality of spacers, and a steam communication port is provided at the upper of each spacer to enable the steam to communicate between adjacent compartments, and lower parts of the compartments are separated from each other to enable the compartments contain different kinds of cooling fluids and/or cooling fluids with different temperatures for subsection cooling of the waste gas. 
   
   
       8 . The waste gas purification apparatus according to  claim 4 , wherein the cooling chamber is separated into a plurality of compartments by a plurality of spacers, and a steam communication port is provided at the upper of each spacer to enable the steam to communicate between adjacent compartments, and lower parts of the compartments are separated from each other to enable the compartments contain different kinds of cooling fluids and/or cooling fluids with different temperatures for subsection cooling of the waste gas. 
   
   
       9 . The waste gas purification apparatus according to  claim 1 , wherein a pumping device is provided between the dust eliminating unit and the absorbing unit, which is used to pump the waste gas output from the dust eliminating unit to the inside bottom part of the absorbing unit to enable the waste gas to be released under the level of the absorbing fluid. 
   
   
       10 . The waste gas purification apparatus according to  claim 1 , wherein the apparatus comprises a plurality of said absorbing units provided in series. 
   
   
       11 . The waste gas purification apparatus according to  claim 10 , wherein a pumping device is provided between adjacent absorbing units, which is used to pump the waste gas output from a former absorbing unit to the inside bottom part of a latter absorbing unit to enable the waste gas to be released under the level of the absorbing fluid contained in the latter absorbing unit. 
   
   
       12 . The waste gas purification apparatus according to  claim 1 , wherein the absorbing unit is provided with an absorbing fluid refreshing device for removing the precipitates in the absorbing unit and for recharging absorbing fluid into the absorbing unit. 
   
   
       13 . The waste gas purification apparatus according to  claim 1 , wherein the absorbing fluid is alkaline solution. 
   
   
       14 . The waste gas purification apparatus according to  claim 1 , wherein the apparatus further comprises a waste gas tank provided at the upstream side of the waste gas cooling unit, which is used to let the waste gas rest therein to remove large dust particles contained in the waste gas before the waste gas is supplied to the waste gas transmission pipe. 
   
   
       15 . A waste gas purification method comprising:
 a cooling step for cooling the waste gas;   a dust eliminating step for eliminating harmful substances and dust contained in the waste gas after the waste gas is processed in the cooling step;   an absorbing step for eliminating carbon dioxide and sulfide contained in the waste gas after the waste gas is processed in the dust eliminating step; and   a purifying step for eliminating harmful substances and dust remained in the waste gas after the waste gas is processed in the absorbing step.   
   
   
       16 . The waste gas purification method according to  claim 15 , wherein the cooling step further comprises a steam recycling step for recycling the steam generated in the cooling step. 
   
   
       17 . The waste gas purification method according to  claim 16 , wherein the absorbing step further comprises an absorbing fluid purifying step for removing precipitates generated in the absorbing step and for recharging absorbing fluid. 
   
   
       18 . The waste gas purification method according to  claim 15 , wherein the method further comprises a resting step for letting the waste gas rest to remove large dust particles contained in the waste gas before the waste gas is processed in the cooling step. 
   
   
       19 . The waste gas purification method according to  claim 16 , wherein the method further comprises a resting step for letting the waste gas rest to remove large dust particles contained in the waste gas before the waste gas is processed in the cooling step. 
   
   
       20 . The waste gas purification method according to  claim 17 , wherein the method further comprises a resting step for letting the waste gas rest to remove large dust particles contained in the waste gas before the waste gas is processed in the cooling step.