Abstract:
An exhaust gas processing apparatus is provided. The apparatus includes a rotor concentrator installed in an inlet, an active carbon adsorption system installed in an outlet, and a switch located between the zeolite rotor concentrator and the active carbon adsorption system for selecting any one (or both) of the two systems to process exhaust gases.

Description:
BACKGROUND OF INVENTION 
     1. Field of the Invention 
     The present invention relates to an apparatus for processing discharging exhaust gas, and more particularly, to an apparatus combining a zeolite rotor concentrator and an active carbon adsorption system together so that the setting cost is lowered and the processing efficiency is raised. 
     2. Description of the Prior Art 
     As the manufacturing process in the semiconductor industry becomes more and more complicated, many poisonous organic gases come with chemical reactions in the process. For protecting the environment and obeying related regulations that are more and more strict, an apparatus for processing exhaust gas is required. Moreover, the setting cost is as important as the efficiency in designing an exhaust gas processing apparatus. 
     Please refer to FIG.  1 . FIG. 1 is a schematic diagram of an exhaust gas processing apparatus  10  according to the prior art. As shown in FIG. 1, the exhaust gas processing apparatus  10  comprises a front fan  12 , a zeolite rotor concentrator  14 , a switch  16 , and a chimney  18 . The exhaust gas is introduced into the exhaust gas processing apparatus  10  by the front fan  12  installed in an inlet, processed by the zeolite rotor concentrator  14 , and discharged by the chimney  18 . Because the organic gas (say IPA, PGMEA, or EKC) contained in the exhaust gas is condensed and burned by the zeolite rotor concentrator  14 , the processing efficiency of the zeolite rotor concentrator  14  will deteriorate when the zeolite ages. In this case, the zeolite rotor concentrator  14  is shut down for examination and necessary measures are adopted (such as replacing zeolite) to recover the normal processing function. The exhaust gas cannot be processed during the examination or zeolite replacement period; therefore the exhaust gas is switched by the switch  16  and discharged via another pipeline and the chimney  18  without being processed. During this period the unprocessed exhaust gas will pollute the environment and violate the environmental regulations. In view of this problem, the pause time of the zeolite rotor concentrator  14  should be taken into consideration when designing new exhaust gas processing models. 
     Please refer to FIG.  2 . FIG. 2 is a schematic diagram of another exhaust gas processing apparatus according to the prior art. As shown in FIG. 2, the exhaust gas processing apparatus  20  comprises a front fan  22 , a switch  23 , a first zeolite rotor concentrator  24 , a second zeolite rotor concentrator  26 , and a chimney  28 . Normally the exhaust gas processing apparatus  20  operates in the same manner with the exhaust gas processing apparatus  10 , the exhaust gas is introduced by the front fan  22 , processed by the first zeolite rotor concentrator  24 , and discharged via the chimney  28 . The difference between the two apparatuses is that when the first zeolite rotor concentrator  24  needs examining or replacement of the zeolite because of zeolite aging or other reasons, the exhaust gas is switched by the switch  23  and processed by the second zeolite rotor concentrator  26 . In this case the exhaust gas processing apparatus is able to operate unceasingly. 
     Although the exhaust gas processing apparatus  20  can solve the pause time problem, it is an impractical design. To set an exhaust gas processing apparatus with a second zeolite rotor concentrator (say flux: 870CMM; concentration: 300 ppm), the setting cost will raise about 1 million US dollars but the average operating time is only five days a year. Therefore a high efficiency and low cost exhaust gas processing apparatus is eagerly required. 
     SUMMARY OF INVENTION 
     It is therefore a primary objective of the claimed invention to provide an exhaust gas processing apparatus that can solve the above-mentioned pause time problem. 
     It is another objective of the claimed invention to provide an exhaust gas processing apparatus that can improve processing efficiency, and lower the setting cost. 
     According to the claimed invention, an exhaust gas processing apparatus having a front fan, a zeolite rotor concentrator, an active carbon adsorption system, a switch, and a chimney is provided. The switch can make the zeolite rotor concentrator and the active carbon adsorption system connect together in series or in parallel. Moreover, the exhaust gas processing apparatus includes a plurality of regulating valves for controlling the exhaust gas flux flowing to the zeolite rotor concentrator and the active carbon adsorption system in different operating modes, a back fan installed in an outlet for pumping out the exhaust gas processed by the active carbon adsorption system, and a check damper installed in the outlet for preventing the exhaust gas processed by the zeolite rotor concentrator from flowing backward to the active carbon adsorption system. 
     It is an advantage of the claimed invention that the active carbon adsorption system is connected to the zeolite rotor concentrator in series or in parallel so that the total processing efficiency is raised. 
     It is another advantage of the claimed invention that the active carbon adsorption system can replace the zeolite rotor concentrator during the examination period so that the problem of a pause time is solved. Moreover, because the exhaust gas processing apparatus of the claimed invention uses an active carbon adsorption system instead of a second zeolite rotor concentrator, the setting cost is much lower. 
    
    
     These and other objectives of the claimed invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1 is a schematic diagram of an exhaust gas processing apparatus according to the prior art. 
     FIG. 2 is another schematic diagram of another exhaust gas processing apparatus according to the prior art. 
     FIG. 3 is a schematic diagram of an exhaust gas processing apparatus in normal mode according the present invention. 
     FIG. 4 is a schematic diagram of the exhaust gas processing apparatus of FIG. 3 in enhancing mode. 
     FIG. 5 is a schematic diagram of the exhaust gas processing apparatus of FIG. 3 in breakdown mode. 
     FIG. 6 is a schematic diagram of an active carbon adsorption system according to the present invention. 
     FIG. 7 is a schematic diagram of another exhaust gas processing apparatus according to the present invention. 
    
    
     DETAILED DESCRIPTION 
     Please refer to FIG.  3 . FIG. 3 is a schematic diagram of the exhaust gas processing apparatus in normal mode according to a preferred embodiment of the present invention. As shown is FIG. 3, the exhaust gas processing apparatus  30  comprises a front fan  32  installed in an inlet, a switch  33 , a zeolite rotor concentrator  34 , an active carbon adsorption system  36 , two regulating valves  38 A and  38 B, a back fan  40  installed in an outlet, a check damper  41 , and a chimney  42 . 
     The exhaust gas is introduced by the front fan  32 , and processed by the zeolite rotor concentrator  34 . In normal mode, the regulating valve  38 A is closed while the regulating valve  38 B is open so that the processed exhaust gas will only pass via the regulating valve  38 B to the chimney  42 . The function of the check damper  41  is to prevent the exhaust gas from flowing backward to the active carbon adsorption system  36 . Also in normal mode the active carbon adsorption system  36  is off, only the zeolite rotor concentrator  34  is working, and its efficiency is set to over 90% to conform to environmental regulations. 
     The processing efficiency of the zeolite rotor concentrator  34  may deteriorate because of zeolite aging or other reasons. When the processing efficiency lowers to 90%, the active carbon adsorption system  36  is connected to the zeolite rotor concentrator  34  in series or in parallel for prolonging the working time of the zeolite rotor concentrator  34 . 
     Please refer to FIG.  4 . FIG. 4 is a schematic diagram of the exhaust gas processing apparatus in enhancing mode according to a preferred embodiment of the present invention. As shown in FIG. 4, the exhaust gas is introduced by the front fan  32 , and processed by the zeolite rotor concentrator  34 . In enhancing mode, the regulating valves  38 A and  38 B are both open so that the zeolite rotor concentrator  34  and the active carbon adsorption system  36  are connected in series. Portions of the exhaust gas processed by the zeolite rotor concentrator  34  will pass to and be reprocessed by the active carbon adsorption system  36  and pumped out to the chimney  42  by the back fan  40 . The remaining exhaust gas that does not pass to the active carbon adsorption system  36  will directly be discharged out via the chimney  42 . In the enhancing mode of this embodiment, the regulating valve  38 A is adjusted to allow only 30% of the exhaust gas to pass, which means 30% of the exhaust gas is reprocessed by the active carbon adsorption system  36 , while the other 70% is directly sent out via the chimney  42 . Assuming that the processing efficiency of the zeolite rotor concentrator  34  and the active carbon adsorption system  36  are set respectively to 90% and 98%, the total processing efficiency will be 93%. It is obvious that not only the processing efficiency is raised but also the working time of the zeolite rotor concentrator  34  is prolonged. 
     Moreover, the zeolite rotor concentrator  34  and the active carbon adsorption system  36  can be connected in parallel. In this case, the switch  33  allows the exhaust gas to flow to both the zeolite rotor concentrator  34  and the active carbon adsorption system  36 . Two regulating valves (not shown) are installed in the inlet of both systems to control the flux flowing to the two processing systems. At this time, the regulating valve  38 A is closed, while the regulating valve  38 B is open. 
     Please refer to FIG.  5 . FIG. 5 is a schematic diagram of the exhaust gas processing apparatus in breakdown mode according to a preferred embodiment of the present invention. When the zeolite rotor concentrator  34  is in breakdown mode or needs examining, the exhaust gas processing apparatus can continue working in the breakdown mode. As shown in FIG. 5, when the zeolite rotor concentrator  34  is not working, the exhaust gas introduced by the front fan  32  is passed to the active carbon adsorption system  36  by switching the switch  33 . At this time the regulating valves  38 A and  38 B are both closed so that the exhaust gas is processed only by the active carbon adsorption system  36  and pumped out to the chimney  42  by the back fan  40 . When the zeolite rotor concentrator  34  is fixed, the exhaust gas processing apparatus will be switched to normal mode or enhancing mode. 
     Please refer to FIG.  6 . FIG. 6 is a schematic diagram of an active carbon adsorption system  36  according to a preferred embodiment of the present invention. As shown in FIG. 6, the active carbon adsorption system  36  comprises two adsorption tanks  37 A and  37 B connected in parallel, and a switch (not shown). While the active carbon adsorption system  36  operates, the exhaust gas can be processed by both the adsorption tanks  37 A and  37 B, or by either one of the adsorption tanks  37 A and  37 B respectively. When one adsorption tank operates, the other adsorption tank can be desorbed in the same time. 
     Please refer to FIG.  7 . FIG. 7 is a schematic diagram of the exhaust gas processing apparatus in another embodiment of the present invention. As shown in FIG. 7, the exhaust gas processing apparatus  30  comprises a front fan  32 , a zeolite rotor concentrator  34 , a dust collector  35 , an active carbon adsorption system  36 , two regulating valves  38 A and  38 B, a back fan  40 , a check damper  41 , and a chimney  42 . It is worth noticing that the dust collector  35  is installed between the zeolite rotor concentrator  34  and the active carbon adsorption system  36 . Because the zeolite rotor concentrator  34  contains silica and alumina, some solid silica and alumina particles may come out with the exhaust gas processed by the zeolite rotor concentrator  34  in enhancing mode. The solid particles may enter and damage the active carbon adsorption system  36 . Therefore, a dust collector is installed to collect solid particles for preventing damages of the active carbon adsorption system  36 . 
     In contrast to the prior art, the exhaust gas processing apparatus of the present invention includes a zeolite rotor concentrator and an active carbon adsorption system and provides different operating modes so that the present invention can solve the pause time problem, lower the setting cost, and further improve the processing efficiency. 
     Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.