Patent Publication Number: US-2007110414-A1

Title: Non-condensing exhaust system

Description:
TECHNICAL FIELD  
      The present invention relates generally to exhaust systems and in particular to exhaust systems for relatively cold exhaust gases.  
     BACKGROUND  
      Exhaust systems that expel cold exhaust gases are susceptible to the production of condensation. An example of a system that produces cold exhaust fumes is a heat exchange system. In a heat exchanger system, thermal energy is transferred between a fluid like LN 2  in a first thermally conductive container and a working fluid in a second thermally conductive container. The LN 2  when placed in the confined space of a thermally conductive container of a heat exchanger will turn into gas (GN 2 ) that is expelled as an exhaust flow. As a result of the cold GN 2  exhaust flow, pipes that direct the exhaust flow can freeze and the formation of condensation will occur. This results in moisture accumulating in areas next to the system expelling the cold exhaust gas.  
      In the past, the moisture problem has been addressed by insulating cold exhaust pipes. However, the insulation needed to wrap the pipe is expensive. Moreover, the insulation can takes up a lot of room. For example, a thickness of insulation of 6 inches or more is common. This is an issue when the space in limited or the system producing the exhaust is portable. Moreover, another problem associated with insulation is that over time mold will develop in and on the insulation creating a health concern. If mold develops, the insulation will have to be replaced.  
      For the reasons stated above and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for a method of effectively in inexpensively dealing with the effects of cold exhaust gas through an exhaust pipe.  
     SUMMARY OF INVENTION  
      The above-mentioned problems of current systems are addressed by embodiments of the present invention and will be understood by reading and studying the following specification.  
      In one embodiment an exhaust system is provided. The exhaust system includes an exhaust pipe and a heater. The exhaust pipe is adapted to contain a flow of cold exhaust gas and the heater is adapted to heat the flow of cold exhaust gas.  
      In another embodiment, a method of preventing condensation on an exhaust pipe having cooled exhaust flowing there through is provided. The method comprises heating the exhaust pipe with a heater embedded with the exhaust pipe.  
      In yet another embodiment, a method of forming an exhaust system is provided. The method comprises integrating a heater with an exhaust pipe that is adapted to contain a cold exhaust flow. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The present invention can be more easily understood and further advantages and uses thereof more readily apparent, when considered in view of the description of the preferred embodiments and the following figures in which:  
       FIG. 1  is a side view of an exhausting system of one embodiment of the present invention;  
       FIG. 2  is a flow diagram illustrating the processing of a cold exhaust flow of one embodiment of the present invention; and  
       FIG. 3  is a flow diagram illustrating a method of manufacturing of one embodiment of the present invention. 
    
    
      In accordance with common practice, the various described features are not drawn to scale but are drawn to emphasize specific features relevant to the present invention. Reference characters denote like elements throughout Figures and text.  
     DETAILED DESCRIPTION  
      In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the inventions may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical and electrical changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the claims and equivalents thereof.  
      Embodiments of the present invention provide a method of processing the flow of cold exhaust through an exhaust pipe to prevent or at least reduce the formation of condensation on the exhaust pipe. In one embodiment, a heater is embedded with the exhaust pipe to heat up the cold exhaust flow as it passes through the pipe thereby preventing condensation from forming on the exhaust pipe.  
      Referring to  FIG. 1 , one embodiment of the present invention is illustrated. As illustrated, this embodiment includes an exhaust pipe  102  and an exhaust heater  104 . The exhaust pipe  102  has a first end  108  that is designed to receive a flow of cold exhaust such as a flow of GN 2 . The flow of cold exhaust is general designated as  106 . The flow of cold exhaust  106  is not limited to GN 2 . The present invention applies to any type of cold exhaust that could produce condensation on the exhaust pipe  102 . The exhaust pipe  102  has a second end  110  that is designed to expel the exhaust  106  after it has been heated. Moreover, as illustrated in  FIG. 1 , in this embodiment, the exhaust pipe as a bend to direct the flow of gas away from a working area or away from the system producing the cold exhausts flow. Other embodiments of the exhaust pipe do not have a bend. Still in other embodiments, the exhaust pipe has more than one bend. Moreover, in some embodiments of the present invention, the exhaust pipe  102  is made from thermally conductive material such as stainless steal, copper and the like. In other embodiments the exhaust pipe is made from non-conductive material.  
      As illustrated in  FIG. 1 , the heater  104  is embedded with the exhaust pipe  102 . In particular, in the embodiment of  FIG. 1 , the heater  104  is wrapped around the exhaust pipe  102 . In one embodiment, the heater  104  is a relatively inexpensive rope or wire heater  104 . Other types of heaters embedded with the exhaust pipe  102  can also be used with embodiments of the present invention and the present invention is not limited to rope or wire heaters.  
       FIG. 2  is a flow diagram  200  illustrating the processing of exhaust with an exhaust system of the present invention to reduce or prevent the formation of condensation on an exhaust pipe. The process begins by directing a flow of cold exhaust into a first end of the exhaust pipe ( 202 ). The flow of cold exhaust is then heated ( 204 ). As illustrated in  FIG. 1 , this is done with a heater that is embedded with the exhaust pipe such as an electric wire heater wrapped around the exhaust pipe. In particular, the heater transfers thermal energy through the thermally conductive exhaust pipe to the cold exhaust flow thereby preventing condensation from forming on the exhaust pipe. The heated exhaust flow is then directed out of a second end of the exhaust pipe ( 206 ).  
      Referring to  FIG. 3 , a flow diagram  300  illustrating the formation of an exhaust system of one embodiment of the present invention is provided. As illustrated, in this embodiment, a bend is formed in an exhaust pipe ( 302 ). As mentioned above, the bend directs the exhaust flow away from a working area or away from the system that is producing the exhaust gas. A first end of a thermally conductive exhaust pipe is designed receive a flow of cold exhaust ( 302 ). The flow of cold exhaust can come from any type of system that outputs an exhaust. A heater is embedded with the exhaust pipe to heat up a flow of cold exhaust ( 304 ). In one embodiment, the heater is a wire heater that is wrapped around the exhaust pipe. A second end of the exhaust pipe is adapted to expel the exhaust flow out of the exhaust pipe ( 306 ).  
      Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement, which is calculated to achieve the same purpose, may be substituted for the specific embodiment shown. This application is intended to cover any adaptations or variations of the present invention. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.