Abstract:
A cooler for cooling product pursuant to a distillation process, including a first substantially enclosed housing with an inlet proximate a first end for receiving product from a distillation unit, and an outlet proximate a second end for discharging cooled product, and a first auger substantially enclosed within the housing for driving the product from the inlet to the outlet, the auger having a helical blade circumscribing a perforated central hollow shaft for transmitting cooled gas into the housing to help cool product within the housing.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to processing carbon-based feedstock, and in particular to a cooler for cooling product after it exits a distillation chamber. 
         [0003]    2. Description of the Related Art 
         [0004]    Coal is an abundant natural resource capable of exploitation to produce large amounts of energy. Coal in its raw form, however, usually contains undesirable compositions in the form of a number of other chemical compositions or elements. One problem faced in the coal industry is that traditional means of extracting energy from coal have been the subject of concerns, due to possible adverse environmental consequences because of the undesirable compositions usually present in raw coal. For example, historically coal has been burned to create heat, such as to turn water into steam to power a turbine and generate electricity. This process generates large amounts of gaseous emissions containing small amounts of the undesirable compositions which harm the environment. As a result, the use of coal as an energy source can cause tension between the need for an economic way to produce energy on the one hand, and environmental concerns on the other. 
         [0005]    During a typical coal processing operation, coal and other carbon-based products are often subjected to distillation processes in order to extract various products therefrom. Typically, the distillation process involves heating a coal feedstock in the absence of oxygen as the feedstock is moved through the distillation chamber, leading to the conversion of the feedstock into useful product. 
         [0006]    When the product leaves the distillation chamber, it is typically very hot. Thus, the product must be cooled in order to further process or package the product. To accomplish this cooling, numerous techniques are used in the industry, each having shortcomings. For example, some coolers use glycol, or other cooling fluid, circulated through and enclosed in the fins of an auger that pulls the feedstock through the cooler. Such a cooler, however, is exceedingly expensive to manufacture and operate. In addition, some prior art coolers vibrate to move the feedstock through a cooling chamber while cool gas is blown in one end of the chamber. This type of cooler, however, is unsuited to many types of feedstock, however, because the air moving through the chamber combined with the agitation of the feedstock created too much dust. 
       SUMMARY OF THE INVENTION 
       [0007]    Briefly, the present invention provides a cooler for cooling product pursuant to a distillation process. The cooler includes a first substantially enclosed housing with an inlet proximate a first end for receiving product from a distillation unit, and an outlet proximate a second end for discharging cooled product, as well as a first auger substantially enclosed within the housing for driving the product from the inlet to the outlet, the auger having a helical blade circumscribing a perforated central hollow shaft for transmitting cooled gas into the housing to help cool product within the housing. 
         [0008]    In some embodiments, the cooler may include a first exhaust port attached to the housing to exhaust gases from within the housing to a location outside the housing. In addition, the housing may have hollow walls for circulating cooling fluid so that the housing acts as a heat exchanger to help cool product within the housing. 
         [0009]    In alternate embodiments, the cooler may further include a second substantially enclosed housing with an inlet proximate a first end for receiving product from the first substantially enclosed housing, and an outlet proximate a second end for discharging cooled product, and a second auger substantially enclosed within the second substantially enclosed housing for driving the product from the inlet to the outlet, the second auger having a helical blade circumscribing a perforated central hollow shaft for transmitting cooled gas into the second substantially enclosed housing to help cool the product within the housing. 
         [0010]    Furthermore, the cooler may include a second exhaust port attached to the second substantially enclosed housing to exhaust gases from within the second substantially enclosed housing to a location outside the second substantially enclosed housing. In addition, the second substantially enclosed housing can have hollow walls for circulating cooling fluid so that the second substantially enclosed housing acts as a heat exchanger to help cool product within the second substantially enclosed housing. 
         [0011]    Another embodiment of the invention provides an apparatus for cooling product. The apparatus includes first and second cooling chambers connected so that product can pass from the first cooling chamber to the second cooling chamber. In addition, the apparatus includes first and second augers, positioned within the first and second chambers, respectively, each auger having a helical blade for driving product through a respective cooling chamber, each helical blade surrounding a perforated hollow shaft that transmits cool gas into the respective chamber through the shaft. 
         [0012]    In some embodiments, the first and second cooling chambers can each have hollow walls through which coolant is passed so that the first and second cooling chambers act as heat exchangers, thereby helping to cool product within the first and second chambers. In addition, the apparatus can further include an exhaust port in each of the first and second chambers to permit gas to escape from the first and second chambers to a location outside of the first and second chambers. 
         [0013]    Yet another embodiment of the invention provides a process for cooling product after the product exits a distillation unit. The process includes the steps of inserting the product into a first chamber enclosed by a first cooler housing, driving the product through the first cooler housing with a first auger having a helical blade circumscribing a perforated hollow shaft, injecting cool gas into the first chamber through the perforated hollow shaft of the first auger to mix with the product in the first chamber, and discharging the cooled product from the first chamber. 
         [0014]    In some embodiments, the process may further include venting gas from within the first chamber in the first cooler housing through a first exhaust port attached to the first cooler housing, cooling the gas after it exits the first exhaust port, and recirculating the cooled gas back into the first chamber through the perforated hollow shaft of the first auger to mix with the product in the first chamber. In addition, the process may include circulating cooling fluid through walls of the first cooler housing so that the first cooler housing acts as a heat exchanger and helps to cool product in the first chamber of the first cooler housing. 
         [0015]    In certain embodiments, the process may include discharging the fluid from the walls of the first cooler housing, cooling the fluid, and recirculating the cooled fluid back through the walls of the first cooler housing so that the first cooler housing acts as a heat exchanger and helps to cool product in the first chamber of the first cooler housing. Furthermore, the process may include inserting the product into a second chamber enclosed by a second cooler housing, driving the product through the second cooler housing with a second auger having a helical blade circumscribing a perforated hollow shaft, injecting cool gas into the second chamber through the perforated hollow shaft of the second auger to mix with the product in the second chamber, and discharging the cooled product from the second chamber. 
         [0016]    In still further embodiments, the process may include the steps of venting gas from within the second chamber in the second cooler housing through a second exhaust port attached to the second cooler housing, cooling the gas after it exits the second exhaust port, and recirculating the cooled gas back into the second chamber through the perforated hollow shaft of the second auger to mix with the product in the second chamber, as well as circulating cooling fluid through walls of the second cooler housing so that the second cooler housing acts as a heat exchanger and helps to cool product in the second chamber of the second cooler housing. 
         [0017]    An alternative embodiment of the process contemplates discharging the fluid from the walls of the second cooler housing, cooling the fluid, and recirculating the cooled fluid back through the walls of the second cooler housing so that the second cooler housing acts as a heat exchanger and helps to cool product in the second chamber of the second cooler housing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1  is a side view of cooler assembly according to an embodiment of the present invention; 
           [0019]      FIG. 2  is a front view of a portion of the cooler assembly of  FIG. 1 ; 
           [0020]      FIG. 3  is a rear view of a portion of the cooler assembly of  FIG. 1 ; 
           [0021]      FIG. 4  is a side view of a cooler assembly according to an embodiment of the present invention and showing augers within the cooler assembly; 
           [0022]      FIG. 5  is an enlarged side view of a portion of the cooler assembly of  FIG. 4 ; 
           [0023]      FIG. 6A  is an enlarged side cross-sectional view of a portion of a cooler assembly according to an embodiment of the present invention; 
           [0024]      FIG. 6B  is an alternate enlarged side cross-sectional view of the portion of the cooler assembly of  FIG. 6A ; 
           [0025]      FIG. 7  is a side view of an auger according to an embodiment of the present invention; and 
           [0026]      FIG. 8  is a cross-sectional view of a portion of the cooler assembly of  FIG. 1  taken along the line  8 - 8  of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0027]    In  FIG. 1 , there is depicted a cooler assembly  10  according to an embodiment of the present invention, including first cooling portion  10   a , and a second cooling portion  10   b . The first cooling portion  10   a  includes a first housing  12  having a first exhaust port  14 , and the second cooling portion  10   b  includes a second housing  16  having a second exhaust port  20 . The first cooling portion  10   a  has an inlet  22  for receiving product from a distillation unit (not shown). The inlet  22  provides a passage for the product to enter a first cooling chamber  24  (best shown in  FIGS. 6A and 6B ). The first cooling portion  10   a  also has an outlet  26  for discharging the product after the product passes through the first cooling chamber  24 . Similarly, the second cooling portion  10   b  has an inlet  28  that can be connected to the outlet  26  of the first cooling portion  10   a , and that receives product from the first cooling chamber  24  into a second cooling chamber  29  (shown in  FIG. 4 ). The second cooling portion  10   b  further includes an outlet  30  for discharging product from the second cooling chamber  29 . Although the inlets  22 ,  28  and outlets  26 ,  30  are shown in the figures to be of particular shapes, it is to be understood that any shape opening can be used for the inlets and outlets of the cooler housings. 
         [0028]    Although the embodiment of  FIG. 1  shows a cooling assembly  10  having two separate cooling portions  10   a ,  10   b , this is simply one possible embodiment. The cooling assembly  10  may also be provided with a single cooling portion having a single housing and a single cooling chamber, or more than two cooling portions with more than two cooling chambers. In addition, in the embodiment shown in  FIG. 1 , the housings  12 ,  16  of the cooler assembly  10  are shown to be tilted at an angle so that the inlets  22 ,  28  are lower than the outlets  26 ,  30 . Although such an orientation can provide certain benefits to the cooler assembly, it is to be understood that the housings  12 ,  16  can be oriented at other angles.  FIGS. 2 and 3  show front and rear views, respectively, of the first cooling portion  10   a  and its associated components. 
         [0029]      FIG. 4  shows an alternate view of the cooler assembly  10 , including the first cooling portion  10   a  and the second cooling portion  10   b . The first cooling portion includes a first housing  12  that surrounds a first inner tube  32 . The first inner tube  32  encloses the first cooling chamber  24 , and an auger  34  extends across the length of the first cooling chamber  24 . Similarly, the second cooling portion includes the second housing  16 , which encloses a second inner tube  36 . The second inner tube  36  encloses the second cooling chamber  29 , and an auger  38  extends across the length of the second cooling chamber  29 . 
         [0030]    In practice, product is fed, by gravity or otherwise, into the inlet  22  of the first cooling portion  10   a , and passes through the first housing  12  into the first cooling chamber  24 . In the first cooling chamber  24 , the auger  34  turns, and the helical blades of the auger  34  transport the product from the inlet  22  to the outlet  26  at an opposite end of the first cooling portion  10   a . At the outlet  26 , the product exits the first cooling chamber  24 , and drops through the outlet  26  into the inlet  28  of the second cooling portion  10   b . The inlet  28  of the second cooling portion  10   b  guides the product through the second housing  16  and into the second cooling chamber  29 . In the second cooling chamber  29 , the auger  38  turns, and the helical blades of the auger  38  transport the product from the inlet  28  to the outlet  30  at an opposite end of the second cooling portion  10   b . At the outlet  30 , the product exits the second cooling chamber  29 . 
         [0031]      FIG. 5  shows an enlarged view of the outlet  26  of the first cooling portion  10   a  and the inlet  28  of the second cooling portion  10   b , to illustrate how the first cooling chamber  24  is connected to the second cooling chamber  29 . Specifically, as the auger  34  of the first cooling chamber  24  turns it drives product through the first cooling portion  10   a  in the direction of arrow A. As the product reaches the outlet  26  of the first cooling portion  10   a , it drops through the outlet  26  and into the inlet  28  of the second cooling portion  10   b  in the direction of arrow B. The inlet  28  of the second cooling portion  10   b  guides the product directly to the auger  38 , which turns to drive the product through the second cooling chamber  29  in the direction indicated by arrow C. 
         [0032]      FIGS. 6A and 6B  show an enlarged side cross-sectional view of the first cooling section  10   a , including some example components that perform cooling functions. As the product is driven through the first cooling section  10   a , there are at least two ways that the product is cooled. A first way is by means of cooling fluid inside the housing  12 , but outside the inner tube  32 . In the embodiment shown, this cooling fluid can be injected into the housing  12  via an inlet valve  40 . After circulating around the inner tube  32  to the opposite end of the housing  12 , the fluid can then be ejected from the housing  12  via an outlet valve  42 . The flow of cooling fluid around the inner tube  32  acts as a heat exchanger, with heat from the product being transferred to the fluid as it flows from the inlet valve  40  to the outlet valve  42 . 
         [0033]    After the fluid exits the housing  12  through the outlet valve  42 , it can be cooled and recirculated back into the inlet valve  40 , thereby creating a closed loop system. In this way, a constant flow of cooling fluid can be moved through the housing  12 , thereby continuously cooling the product in the cooling chamber  24 . In alternate embodiments, the fluid exiting the outlet valve  42  can be disposed of, and new cooling fluid can be injected into the housing  12  via the inlet valve  40 . Any appropriate cooling fluid can be used in the housing  12  to help cool the product, including water. 
         [0034]    The product can also be cooled by means of cool gas injected directly into the cooling chamber and mixed with the product. For example,  FIG. 7  shows the auger  34 , according to an embodiment of the invention, including gas injection holes  44 . In addition,  FIG. 8  shows a cross-sectional view of the first cooling section  10   a , including the auger  34  within the inner tube  34 , which includes a hollow shaft  46 . As the auger  34  rotates in the cooling chamber  24 , a cooling gas can be injected into the hollow shaft  46  of the auger  34  via an auger inlet valve  48  (shown in  FIG. 6B ). The cooling gas travels through the hollow shaft  46  along the length of the auger shaft, and exits the gas injection holes  44  into the cooling chamber  24 . When the cooling gas enters the cooling chamber  24 , it mixes with the product, thereby helping to cool the product. 
         [0035]    Also shown in  FIG. 8  is the exhaust port  14 . The exhaust port  14  extends through the housing  12  and attaches to the inner tube  32 . As the cooling gas enters the cooling chamber  24 , and begins to cool the product, exhaust gases are purged from the cooling chamber  24  through the exhaust port  14 . Accordingly, the exhaust port  14  provides a vent for the hot gases to escape as the cooling chamber  24  as the product cools. The exhaust port  14  may be sealingly attached to the inner tube  32  to prevent cooling liquid inside the housing  12  from entering the cooling chamber  24 . 
         [0036]    Simultaneous use of the different cooling techniques described herein provides advantages over known cooling methods because the dual cooling techniques act together to cool the product faster. It is to be understood, however, that either technique may be used individually without departing from the spirit and scope of the invention. In addition, any of the cooling techniques described herein could be combined with other known cooling techniques to decrease cooling times and increase the efficiency of the cooler assembly  10 . 
         [0037]    In addition, the specific cooling techniques described herein are described in relation to a single cooling section  10   a . Some embodiments of the invention, however, contemplate the use of both cooling techniques in more than one cooling section. For example, both techniques can be utilized in the second cooling section  10   b . In embodiments where both the first and second cooling sections  10   a  and  10   b  are used together, use of both cooling techniques provides substantial benefits and introduces greater efficiency to the cooler assembly  10  as a whole. 
         [0038]    Additional embodiments of the invention include a process for cooling product using the above-described cooler assembly. According to the process, product is inserted into the cooling chamber  24  of the first cooling section  10   a  through the inlet  22  thereof. Inside the first cooling chamber  24 , the product is driven by a first auger  34  that has a helical blade circumscribing a hollow shaft  46 . 
         [0039]    As the product is driven through the first cooling chamber  24  by the first auger  34 , cool gas can be injected into the cooling chamber  24  through perforations, or injection holes  44 , in the shaft. The cool gas can then mix with the product to help cool the product. As cool gas is injected into the cooling chamber  24 , hot gases can be vented from the cooling chamber through an exhaust port  14 . In some embodiments, the gas exiting the exhaust port can be captured and re-cooled, after which it can be recirculated back into the chamber. 
         [0040]    Also as the product is driven through the first cooling chamber  24 , cooling fluid can be circulated through the housing  12  surrounding the inner tube  32  that encloses the cooling chamber  24 . This cooling fluid can act as a heat exchanger, transferring heat from the product to the cooling fluid. Use of this cooling method along with the direct injection of cool gas within the cooling chamber  24  increases the efficiency of the cooler assembly  10  and decreases the cooling time of the product. After the cooling fluid has been circulated through the housing  12 , it can be cooled and recirculated back into the housing for further cooling. 
         [0041]    After the product is driven through the cooling chamber  24 , it is discharged from the cooling chamber  24  through the outlet  26  thereof. From there, in some embodiments, the product is fed into a second cooling chamber  29  through a second inlet  28 . Inside the second cooling chamber  29 , the product is driven by a second auger  38  that has a helical blade circumscribing a hollow shaft. 
         [0042]    As the product is driven through the second cooling chamber  29  by the second auger  38 , cool gas can be injected into the cooling chamber  29  through perforations, or injection holes, in the shaft. The cool gas can then mix with the product to help cool the product. As cool gas is injected into the cooling chamber  29 , hot gases can be vented from the cooling chamber through a second exhaust port  20 . In some embodiments, the gas exiting the second exhaust port  20  can be captured and re-cooled, after which it can be recirculated back into the chamber. 
         [0043]    Also as the product is driven through the second cooling chamber  29 , cooling fluid can be circulated through the second housing  16  surrounding the second inner tube  36  that encloses the second cooling chamber  29 . This cooling fluid can act as a heat exchanger, transferring heat from the product to the cooling fluid. Use of this cooling method along with the direct injection of cool gas within the second cooling chamber  29  increases the efficiency of the cooler assembly  10  and decreases the cooling time of the product. After the cooling fluid has been circulated through the second housing  16 , it can be cooled and recirculated back into the housing for further cooling. After the product is driven through the second cooling chamber  29 , it is discharged from the second cooling chamber  29  through the outlet  30  thereof. 
         [0044]    The invention has been sufficiently described so that a person with average knowledge in the matter may reproduce and obtain the results mentioned in the invention herein. Nonetheless, any skilled person in the field of technique, subject of the invention herein, may carry out modifications not described in the request herein, to apply these modifications to a determined structure, or in the manufacturing process of the same, requires the claimed matter in the following claims; such structures shall be covered within the scope of the invention. 
         [0045]    It should be noted and understood that there can be improvements and modifications made of the present invention described in detail above without departing from the spirit or scope of the invention as set forth in the accompanying claims.