Abstract:
A heat exchanger which is used primarily in oil and gas operations to heat tanks of liquids, such as drilling mud, water, heavy oil or other such fluids from freezing or becoming too viscous to pump.

Description:
BACKGROUND 
       [0001]    This invention generally relates to using a heat exchanger to prevent a tank containing liquid from freezing or to maintain the temperature of the liquid in a tank at a desired temperature. 
         [0002]    Certain industrial applications require large volumes of heated fluid, primarily water, but not excluding other fluids such as drilling mud, hydrocarbons or caustic solutions. Although this patent application is not limited to any one of these types of fluids, this application will refer to these fluids as water. Also, although many types of fluids, such as glycol and oil, may be used as a heat generator fluid, this application will refer to glycol as the heat generator fluid. 
         [0003]    Specific environments, such as that of the energy industry, may require that an open flame not be present. The fluid heating system and process described herein was created to heat fluids in such environments. 
         [0004]    Common practice, for example, has been to truck water to several tanks located at the site of an oil or gas well. The water is typically heated by open flamed trucks which utilize, for example, diesel, natural gas or propane fired burners. However, these burners are inefficient (e.g., utilizing excessive amounts of fuel) and hazardous (e.g., causing fires, severe burns, and fatalities). 
         [0005]    A flameless heat exchanger system removes these hazards by circulating hot glycol (e.g., temperature less than 100 degrees Celsius) within the tank, and returning it to the heat source. There is no risk of explosion or burns due to open flames or high temperature steam. 
         [0006]    The heat exchanger may be installed by inserting it into a flanged opening (e.g., four inches in diameter) in the tank, when the tank is empty. Although a four inch flange is a standard size in the oil and gas industry, the heat exchanger can be any size, and can be inserted in any size of opening. When the tanks are filled, a heater is moved to the tank site, connected to the heat exchanger, and heats the water, or any other fluid contained in the tanks, to a desired temperature. The heater generates hot glycol, which is pumped to the tanks, circulated through the heat exchanger, and returned to the heater. 
         [0007]    This process may be continuous (or interrupted) and may be continued, for example, until the fluid in the tank is heated to the desired temperature. Multiple tanks can be heated, for example, by connecting them in series with hoses and quick connect couplers or with the use of a manifold and connected in parallel. The heating process is efficient and safe. 
       SUMMARY 
       [0008]    One aspect of the present invention includes a heat transfer tube, a flange, and quick connect adaptors. The heat transfer tube is configured such that the length of the tube is long enough to provide maximum amount of heating area within the tank, yet shorter than the diameter of the tank. The tube may be configured to include one or more bends and differing lengths or tubing, depending on the tank flange size. The flange is configured to have approximately the same diameter as the tank flange, which can be any size required for the tank. Quick connect adapters may be used so that hoses (e.g., which supply the glycol) can be quickly coupled and uncoupled from the heat exchanger, which are providing the hot glycol. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The following drawings illustrate examples of various components of the invention disclosed herein, and are for illustrative purposes only. 
           [0010]      FIG. 1  is a drawing one embodiment of a heat exchanger; and 
           [0011]      FIG. 2  is a drawing of one embodiment of a heat exchanger inside a tank. 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    While the present invention may be embodied in many different forms, a number of illustrative embodiments are described herein with the understanding that the present disclosure is to be considered as providing examples of the principles of the invention and such examples are not intended to limit the invention to preferred embodiments described herein and/or illustrated herein 
         [0013]    Reference will now be made to  FIGS. 1 and 2 , a more detailed description of the heat exchanger process. Each component will be described in detail, followed by an overview of the heat exchanger process. 
         [0014]    The largest component of heat exchanger  1 , for example, is heat transfer tube  10 . In this example, heat transfer tube  10  (e.g., may be multiple tubes) is constructed of stainless steel (e.g., provides corrosion resistance for caustic fluids); however, it is known to use any similar non-corrosive material, such as steel, or copper. The heat transfer tube  10  can be constructed of varying sizes, mainly dependent on the flange size of the tank that it is inserted into. The heat transfer tube  10  may be configured to include one or more bends, depending, in part on the tank flange size. 
         [0015]    Attached to the heat transfer tubes  10  is heat exchanger flange  20 . In this example, heat exchange flange  20  is constructed of the same material as the heat exchanger tubes (e.g., stainless steel); however, it is known to use any similar non-corrosive material, such as steel, or copper. The heat exchange flange  20  is attached to or formed integral with the heat transfer tube  10 . In this example, the heat exchange flange  20  is welded to the heat transfer tube  10 . However, one of ordinary skill in the art would connect the flange  20  to the tube  10  in any safe and secure manner. In this example, the heat exchange flange  20  includes a plurality of through holes having a smaller diameter, for example, than an opening in the tank flange  60  described below. The through holes are configured to allow the heating fluid (e.g., hot glycol) to circulate to the heat transfer tubes  10 . 
         [0016]    Pipes  30 A and  30 B are attached to an opposite side of the heat exchanger flange  20  as the heat transfer tube  10 . 
         [0017]    The pipes  30 A and  30 B are attached to or formed integral with a surface of the heat exchanger flange  20 . In this example, the pipes  30 A and  30 B are welded to the surface. Quick connect couplers  40 A and  40 B are attached to an end of the pipes  30 A and  30 B that is away from the surface of the heat exchanger flange  20 . In this example, the quick connect couplers  40 A and  40 B are hydraulic quick connect couplers and are screwed on to the end of the pipes  30 A and  30 B. The quick connect couplers  40 A and  40 B are arranged between the pipes  30 A and  30 B and hoses  50 A and  50 B. The quick connect couplers  40 A and  40 B are configured to connect the hoses  50 A and  50 B to the pipes  30 A and  30 B in order to transfer a heated fluid (e.g., hot glycol) to the heat exchanger  1 . The hoses  50 A and  50 B can be constructed of various dimensions and can be connected to other hoses or a heater with quick connect couplers, such as the type described above. 
         [0018]    Tank flange  60  is attached to or formed integral with a surface of tank  1  (e.g., drum), as shown in  FIG. 2 . In this example, the tank flange  60  is welded to the tank  1 . The tank flange  60  may be configured of varying dimensions, preferably having a diameter approximately the same as that of the heat exchanger flange  20 . In this example, the tank flange  60  has approximately the same diameter as the heat exchanger flange  20 . An opening (through hole) is formed in the tank flange and is configured to accommodate the passage of the heat transfer tubes  10  into the tank  1 . In this example, the opening is approximately four-inches in diameter. However, one of ordinary skill in the art would utilize varying sizes that are appropriate. 
         [0019]    The tank flange  60  may include a pipe having the same diameter as the opening formed in the tank flange  60  and extending from the tank flange  60  into the tank  1 . In this example, a bolt pattern formed on the tank flange  60  is designed to match a bolt pattern formed on the heat transfer flange  20  so that the tank flange  60  can be fixed to the heat transfer flange such that the heat transfer tubes  10  extend through the pipe of tank flange  60  and into the tank  1 . 
         [0020]    In this example, hot glycol travels through the hose  50 A, which is connected to the quick connect coupler  40 A and then flows into the drum through a first opening in the flanges  20 ,  60  to an inside of the heat transfer tube  10  arranged inside the drum. The glycol continuously flows inside the heat transfer tube  10  (e.g., generally u-shaped in this example) and exits the drum through a second opening in the flanges  20 ,  60  to the quick connect coupler  40 B and then exits the heat exchanger through the hose  50 B. 
         [0021]    The process can be reversed so that either coupler can be a used as an intake or exit for the hot glycol. The hot glycol can be pumped through the heat exchanger continuously or intermittently as required. 
         [0022]    Although an embodiment of the instant invention has been described above and illustrated in the accompanying drawing in order to be more clearly understood, the above description is made by way of example and not as a limitation to the scope of the instant invention. It is contemplated that various modifications apparent to one of ordinary skill in the art could be made without departing from the scope of the invention which is to be determined by the following claims.