Abstract:
An environmental protection liquid fuel generator, in which the fuel oil generator is a structure made from a receiving device, an esterification device, a first standing separation device, a compression distillation device, an acid-base neutralization device, a second standing separation device, and a decompression distillation device. A mixed proportion of a vegetable oil and an alkide (catalyzing enzyme) is placed into the fuel generator, and the esterification device is used to increase electron affinity and accelerate the reaction rate, thereby enabling the distillation of low polluting and low sulfur containing environmental protection fuel oil.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    (a) Field of the Invention 
         [0002]    The present invention provides an environmental protection liquid fuel generator, which places a mixed proportion of a vegetable oil and an alkide (catalyzing enzyme) into a fuel generator, and uses an esterification device to increase electron affinity and accelerate the reaction rate, thereby enabling distillation of low polluting and low sulfur containing environmental protection fuel oil. 
         [0003]    (b) Description of the Prior Art 
         [0004]    Rapid industrial development and the increase in use of vehicles have brought about the serious problems of air pollution, and has become an important issue that everyone needs to squarely face up to. The components of the exhaust gas emitted after fuel combustion pollute the air and affect human health, as well as causing adverse effects on the earth from gradual global warming. Referring to  FIG. 1 , which shows the ecological cycle of current oil material and includes a. planting, growing, and harvesting of crops; b. processing of crops to manufacture oil material; c. subpackaging and transporting of the oil material; d. fuel burning engines using the oil material; and e. mixing of the gas emission with air and light. Accordingly, air quality becomes progressively worse through the effects of this cyclic production, which impacts crop development and nourishment. Hence, the standards for material emissions into the air need to be lowered to achieve an improvement in air pollution. 
         [0005]    An essential factor in improving air pollution and emission standards is the lowering of the sulfur content in fuel oil, with an objective of implementing a plan to lower the sulfur content of petroleum products to 0.3%. However, there are limitations to lowering sulfur content, as well as limitations on the production capacity of low sulfur fuel oil and difficulties in purchase thereof. 
         [0006]    Nevertheless, there are two approaches that can be taken to resolve and improve the existing shortcomings and problems derived from using diesel oil, including using biological diesel oil (BIO Diesel) and dimethyl ether (DME). These two materials are both environmental protection materials obtained by extraction and purification, and can be used as a substitute for diesel oil, thereby reducing pollution problems produced by existing petroleum diesel oil. Furthermore, these two products were developed because of their environmental protection qualities. However, they are not the optimum substitutes and have the following shortcomings: BIO Diesel: 1. cold starting of a vehicle is poor; 2. excessive high speed operating horsepower, and poor high speed performance; and dimethyl ether (DME): 1. Unsafe—DME is a toxic gaseous fuel, which very easily results in gas leakage, bringing about intoxication; 2. high cost; 3. poor lubricity—during fuel injection the DME has no lubricity and thus requires the addition of a lubricating oil to increase the degree of lubrication of the fuel. Moreover, currently developed BIO Diesel oils still rely on the refinement of mineral diesel oil, and when using a BIO Diesel oil containing a high content of mineral diesel oil pollution problems similar to using petroleum diesel oil still exist. In addition, the same hidden pollution problems still exist because of the air pollution component sulfur contained in mineral diesel oil. 
         [0007]    Hence, in light of the shortage of energy resources and the problems of environment pollution brought about by using energy resources, the author of the present invention has attentively researched various methods to resolve such issues to finally develop an environmental protection liquid fuel generator. The environmental protection liquid fuel generator uses an alkide (catalyzing enzyme) and a vegetable oil, and adopts an esterification device of a fuel oil generator to increase electron affinity and accelerate the reaction rate to produce an environmental protection synthetic low sulfur fuel oil. Accordingly, the present invention achieves a fuel oil that is more environmentally friendly, as well as being efficient, safe, and of low cost. In addition, when used in combination with BIO Diesel oil, general top grade diesel oil or common diesel oil, the environmental protection synthetic low sulfur fuel oil has the ability to resolve or alleviate the problems of conventional high sulfur diesel oil. 
       SUMMARY OF THE INVENTION 
       [0008]    The primary objective of the present invention is to provide an environmental protection liquid fuel generator, wherein an embodiment of the liquid fuel generator comprises a receiving device, an esterification device, a first standing separation device, a compression distillation device, an acid-base neutralization device, a second standing separation device, and a decompression distillation device. 
         [0009]    A second objective of the present invention is to provide the environmental protection liquid fuel generator wherein a mixed proportion of a vegetable oil and an alkide is placed in an embodiment of the liquid fuel generator, and the esterification device is used to bring about a reaction and the distillation of low polluting and low sulfur containing environmental protection fuel oil. 
         [0010]    To enable a further understanding of said objectives and the technological methods of the invention herein, a brief description of the drawings is provided below followed by a detailed description of the preferred embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a schematic view of an ecological cycle of oil material of the prior art. 
           [0012]      FIG. 2  is a schematic view of a fuel oil generator for an environmental protection liquid fuel oil generator of the present invention. 
           [0013]      FIG. 3  is a schematic flow chart of material addition for an environmental protection liquid fuel oil generator of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0014]    Referring first to  FIG. 2 , which shows an environmental protection liquid fuel generator of the present invention that is a synthetic low sulfur fuel oil generator, wherein a fuel oil generator  1  is a structure comprising: a receiving device  10 , an esterification device  11 , a first standing separation device  12 , a compression distillation device  13 , an acid-base neutralization device  14 , a second standing separation device  15 , and a decompression distillation device  16 , The receiving device  10  is a feeder container, and the receiving device corresponds to the esterification device  11 . The esterification device  11  enables heating of the additives, which respectively corresponds to the receiving device  10  and the first standing separation device  12 . The first standing separation device  12  enables separation of ester oil and glycerine, which respectively corresponds to the esterification device  11  and the compression distillation device  13 . Moreover, the first standing separation device  12  is provided with a gas recovery conduit  120  to be corresponded to the esterification device  11 . The compression distillation device  13  enables removal of water content, which respectively corresponds to the first standing separation device  12  and the acid-base neutralization device  14 . The acid-base neutralization device  14  enables the addition of acetic acid to the material mixture, which respectively corresponds to the compression distillation device  13  and the second standing separation device  15 . The second standing separation device  15  enables separation of ester oil and water content, which respectively corresponds to the acid-base neutralization device  14  and the decompression distillation device  16 . The decompression distillation device  16  enables refinement of the environmental protection liquid fuel oil, with the refined fuel oil being extracted from an extraction outlet  160 . Accordingly, an environmental protection liquid fuel oil for use is extracted and purified by means of the fuel oil generator  1 . 
         [0015]    Referring next to  FIG. 2  and  FIG. 3 , which show the environmental protection liquid fuel generator of the present invention, wherein fuel oil with environmental protection characteristics produced by the fuel oil generator  1  forms a synthetic low sulfur biological diesel oil (BIO Diesel)  17 . The BIO Diesel oil  17  with low sulfur content is primarily formed by adding a mixed proportion of a vegetable oil and an alkide (catalyzing enzyme) to the fuel oil generator  1 , which extracts and purifies the BIO Diesel oil to reduce the amount of sulfur contained in the fuel oil and provide for different flash points. 
         [0016]    Accordingly, the mixed proportion of an alkide (catalyzing enzyme), which is a decane, an 11 alkane, or a 12 alkane, with a vegetable oil required a flash point between 45° C.˜70.5° C., and the sulfur content was below 2.3 ppm (parts per million). Hence, with a sulfur content below 2.3 ppm, it produces a gas that is close to being completely non-polluting. Moreover, after use, the discharged waste gas is environmentally friendly and non-polluting, and no black smoke is produced. 
         [0017]    Referring to the test results from a SGS Test Report, wherein proportion by weight of a vegetable oil and alkide (catalyzing enzyme) is 50%+50%, and the vegetable oil is: 
         [0018]    a. soybean oil with flash point: 45° C., and sulfur content: 0.22 ppm; 
         [0019]    Test Results: 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                 Test Item 
                 Unit 
                 Test Method 
                 Test Result 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                  1. Density at 15.5° C. 
                 g/ml 
                 ASTM D4052 
                 0.8496 
               
               
                  2. Flash point 
                 ° C. 
                 ASTM D93 
                 45.0 
               
               
                  3. Ignition point 
                 ° C. 
                 ASTM D92 
                 56 
               
               
                  4. Water content &amp; sediment 
                 Vol % 
                 ASTM D1796 
                 &lt;0.1 
               
               
                  5. Viscosity at 40° C. 
                 cSt 
                 ASTM D445 
                 4.538 
               
               
                  6. Ash mass content 
                 wt % 
                 ASTM D482 
                 &lt;0.01 
               
               
                  7. Sulfur content 
                 ppm 
                 ASTM D5453 
                 0.22 
               
               
                  8. Copper corrosiveness 
                 — 
                 ASTM D130 
                 1a 
               
               
                  9. Pour point 
                 ° C. 
                 ASTM D97 
                 −30 
               
               
                 10. Carbon residue 
                 wt % 
                 ASTM D4530 
                 0.18 
               
               
                 11. Gross heat of combustion 
                 Kcal/Kg 
                 ASTM D240 
                 10254 
               
               
                 12. Net heat of combustion 
                 Kcal/Kg 
                 ASTM D240 
                 9720 
               
               
                 13. Carbon content 
                 wt % 
                 ASTM D5291 
                 72.93 
               
               
                 14. Hydrogen content 
                 wt % 
                 ASTM D5291 
                 10.54 
               
               
                 15. Oxygen content 
                 wt % 
                 Element 
                 6.65 
               
               
                   
                   
                 analyzer 
               
               
                 16. Phosphorus content 
                 ppm 
                 Element 
                 Not detected 
               
               
                   
                   
                 analyzer 
                 (&lt;2) 
               
               
                   
               
               
                 1a: Light orange color, almost the same color as freshly polished copper strip 
               
             
          
         
       
     
         [0020]    b. cotton seed oil with flash point: 45° C., sulfur content: 1.1 ppm; 
         [0021]    Test Results: 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                 Test Item 
                 Unit 
                 Test Method 
                 Test Result 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                  1. Density at 15.5° C. 
                 g/ml 
                 ASTM D4052 
                 0.8492 
               
               
                  2. Flash point 
                 ° C. 
                 ASTM D93 
                 45.0 
               
               
                  3. Ignition point 
                 ° C. 
                 ASTM D92 
                 56 
               
               
                  4. Water content &amp; sediment 
                 Vol % 
                 ASTM D1796 
                 &lt;0.1 
               
               
                  5. Viscosity at 40° C. 
                 cSt 
                 ASTM D445 
                 4.492 
               
               
                  6. Ash mass content 
                 wt % 
                 ASTM D482 
                 &lt;0.01 
               
               
                  7. Sulfur content 
                 ppm 
                 ASTM D5453 
                 1.1 
               
               
                  8. Copper corrosiveness 
                 — 
                 ASTM D130 
                 1a 
               
               
                  9. Pour point 
                 ° C. 
                 ASTM D97 
                 −27 
               
               
                 10. Carbon residue 
                 wt % 
                 ASTM D4530 
                 0.21 
               
               
                 11. Gross heat of combustion 
                 Kcal/Kg 
                 ASTM D240 
                 10233 
               
               
                 12. Net heat of combustion 
                 Kcal/Kg 
                 ASTM D240 
                 9699 
               
               
                 13. Carbon content 
                 wt % 
                 ASTM D5291 
                 79.59 
               
               
                 14. Hydrogen content 
                 wt % 
                 ASTM D5291 
                 10.54 
               
               
                 15. Oxygen content 
                 wt % 
                 Element 
                 4.52 
               
               
                   
                   
                 analyzer 
               
               
                 16. Phosphorus content 
                 ppm 
                 Element 
                 Not detected 
               
               
                   
                   
                 analyzer 
                 (&lt;2) 
               
               
                   
               
               
                 1a: Light orange color, almost the same color as freshly polished copper strip 
               
             
          
         
       
     
         [0022]    c. rapeseed oil with flash point: 45° C., sulfur content: 2.3 ppm; 
         [0023]    Test Results: 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                 Test Item 
                 Unit 
                 Test Method 
                 Test Result 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                  1. Density at 15.5° C. 
                 g/ml 
                 ASTM D4052 
                 0.8477 
               
               
                  2. Flash point 
                 ° C. 
                 ASTM D93 
                 45.0 
               
               
                  3. Ignition point 
                 ° C. 
                 ASTM D92 
                 56 
               
               
                  4. Water content &amp; sediment 
                 Vol % 
                 ASTM D1796 
                 &lt;0.1 
               
               
                  5. Viscosity at 40° C. 
                 cSt 
                 ASTM D445 
                 4.614 
               
               
                  6. Ash mass content 
                 wt % 
                 ASTM D482 
                 &lt;0.01 
               
               
                  7. Sulfur content 
                 ppm 
                 ASTM D5453 
                 2.3 
               
               
                  8. Copper corrosiveness 
                 — 
                 ASTM D130 
                 1a 
               
               
                  9. Pour point 
                 ° C. 
                 ASTM D97 
                 −39 
               
               
                 10. Carbon residue 
                 wt % 
                 ASTM D4530 
                 0.21 
               
               
                 11. Gross heat of combustion 
                 Kcal/Kg 
                 ASTM D240 
                 10230 
               
               
                 12. Net heat of combustion 
                 Kcal/Kg 
                 ASTM D240 
                 9732 
               
               
                 13. Carbon content 
                 wt % 
                 ASTM D5291 
                 68.99 
               
               
                 14. Hydrogen content 
                 wt % 
                 ASTM D5291 
                 9.83 
               
               
                 15. Oxygen content 
                 wt % 
                 Element 
                 4.98 
               
               
                   
                   
                 analyzer 
               
               
                 16. Phosphorus content 
                 ppm 
                 Element 
                 Not detected 
               
               
                   
                   
                 analyzer 
                 (&lt;2) 
               
               
                   
               
               
                 1a: Light orange color, almost the same color as freshly polished copper strip 
               
             
          
         
       
     
         [0024]    d. palm oil with flash point: 45° C., sulfur content: 2.3 ppm. 
         [0025]    Test Results: 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                 Test Item 
                 Unit 
                 Test Method 
                 Test Result 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                  1. Density at 15.5° C. 
                 g/ml 
                 ASTM D4052 
                 0.8445 
               
               
                  2. Flash point 
                 ° C. 
                 ASTM D93 
                 45.0 
               
               
                  3. Ignition point 
                 ° C. 
                 ASTM D92 
                 56 
               
               
                  4. Water content &amp; sediment 
                 Vol % 
                 ASTM D1796 
                 &lt;0.1 
               
               
                  5. Viscosity at 40° C. 
                 cSt 
                 ASTM D445 
                 4.371 
               
               
                  6. Ash mass content 
                 wt % 
                 ASTM D482 
                 &lt;0.01 
               
               
                  7. Sulfur content 
                 ppm 
                 ASTM D5453 
                 1.1 
               
               
                  8. Copper corrosiveness 
                 — 
                 ASTM D130 
                 1a 
               
               
                  9. Pour point 
                 ° C. 
                 ASTM D97 
                 −15 
               
               
                 10. Carbon residue 
                 wt % 
                 ASTM D4530 
                 0.23 
               
               
                 11. Gross heat of combustion 
                 Kcal/Kg 
                 ASTM D240 
                 10276 
               
               
                 12. Net heat of combustion 
                 Kcal/Kg 
                 ASTM D240 
                 9739 
               
               
                 13. Carbon content 
                 wt % 
                 ASTM D5291 
                 78.64 
               
               
                 14. Hydrogen content 
                 wt % 
                 ASTM D5291 
                 10.59 
               
               
                 15. Oxygen content 
                 wt % 
                 Element 
                 3.95 
               
               
                   
                   
                 analyzer 
               
               
                 16. Phosphorus content 
                 ppm 
                 Element 
                 Not detected 
               
               
                   
                   
                 analyzer 
                 (&lt;2) 
               
               
                   
               
               
                 1a: Light orange color, almost the same color as freshly polished copper strip 
               
             
          
         
       
     
         [0026]    In the test results, when the flash point is at 45° C., the sulfur content is within 2.3 ppm, which clearly achieves a reduction in the discharge amount of sulfur. 
         [0027]    When the proportion by weight of a vegetable oil and alkide (catalyzing enzyme) is 75%+25%, the test results were as follows: 
         [0028]    Test Results: 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                 Test Item 
                 Unit 
                 Test Method 
                 Test Result 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                  1. Density at 15.5° C. 
                 g/ml 
                 ASTM D4052 
                 0.8834 
               
               
                  2. Flash point 
                 ° C. 
                 ASTM D93 
                 51.0 
               
               
                  3. Viscosity at 50° C. 
                 cSt 
                 ASTM D445 
                 8.210 
               
               
                  4. Viscosity at 70° C. 
                 cSt 
                 ASTM D445 
                 5.438 
               
               
                  5. Viscosity at 90° C. 
                 cSt 
                 ASTM D445 
                 4.044 
               
               
                  6. Viscosity at 100° C. 
                 cSt 
                 ASTM D445 
                 3.512 
               
               
                  7. Ash mass content 
                 wt % 
                 ASTM D482 
                 0.003 
               
               
                  8. Sulfur content 
                 ppm 
                 ASTM D5433 
                 2.2 
               
               
                  9. Pour point 
                 ° C. 
                 ASTM D97 
                 −27 
               
               
                 10. Gross heat of combustion 
                 Kcal/Kg 
                 ASTM D240 
                 9905 
               
               
                 11. Net heat of combustion 
                 Kcal/Kg 
                 ASTM D240 
                 9180 
               
               
                 12. Carbon content 
                 wt % 
                 Element 
                 72.50 
               
               
                   
                   
                 analyzer 
               
               
                 13. Hydrogen content 
                 wt % 
                 Element 
                 14.3 
               
               
                   
                   
                 analyzer 
               
               
                 14. Oxygen content 
                 wt % 
                 Element 
                 8.72 
               
               
                   
                   
                 analyzer 
               
               
                   
               
             
          
         
       
     
         [0029]    When the flash point is 51° C., the sulfur content is within 2.2 ppm. Hence, the values produced by different mixed proportions of the vegetable oil and alkide similarly achieve a sulfur content lower than 2.3 ppm. 
         [0030]    When the proportion by weight of a vegetable oil and alkide (catalyzing enzyme) is 60%+40%, the test results were as follows: 
         [0031]    Test Results: 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                 Test Item 
                 Unit 
                 Test Method 
                 Test Result 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                  1. Density at 15.5° C. 
                 g/ml 
                 ASTM D4052 
                 0.9502 
               
               
                  2. Flash point 
                 ° C. 
                 ASTM D93 
                 95.0 
               
               
                  3. Viscosity at 50° C. 
                 cSt 
                 ASTM D445 
                 7.137 
               
               
                  4. Viscosity at 70° C. 
                 cSt 
                 ASTM D445 
                 4.731 
               
               
                  5. Viscosity at 90° C. 
                 cSt 
                 ASTM D445 
                 3.368 
               
               
                  6. Viscosity at 100° C. 
                 cSt 
                 ASTM D445 
                 2.966 
               
               
                  7. Ash mass content 
                 wt % 
                 ASTM D482 
                 &lt;0.001 
               
               
                  8. Sulfur content 
                 ppm 
                 ASTM D2622 
                 0.006 
               
               
                  9. Pour point 
                 ° C. 
                 ASTM D97 
                 &lt;−45 
               
               
                 10. Gross heat of combustion 
                 Kcal/Kg 
                 ASTM D240 
                 9721 
               
               
                 11. Net heat of combustion 
                 Kcal/Kg 
                 ASTM D240 
                 9192 
               
               
                 12. Carbon content 
                 wt % 
                 Element 
                 81.67 
               
               
                   
                   
                 analyzer 
               
               
                 13. Hydrogen content 
                 wt % 
                 Element 
                 10.43 
               
               
                   
                   
                 analyzer 
               
               
                 14. Oxygen content 
                 wt % 
                 Element 
                 5.62 
               
               
                   
                   
                 analyzer 
               
               
                   
               
             
          
         
       
     
         [0032]    When the flash point is 95° C., the sulfur content is within 0.006 ppm. Accordingly, the higher the flash point, the lower the sulfur content produced. In addition, the discharged gas is non-polluting and no black smoke is produced. Hence, there is no production of acid rain to break down the atmospheric layer, thus, global warming can be slowed down to alleviate changes in the global climate system and the ecological environment. 
         [0033]    When the proportion by weight of a vegetable oil and an alkide (catalyzing enzyme) is 50%+50%, then the cetane number test results for the respective vegetable oils were: 
         [0034]    a. palm oil→45 
         [0035]    Test Results: 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Test Item 
                 Unit 
                 Test Method 
                 Test Result 
               
               
                   
                   
               
             
             
               
                   
                 Cetane number 
                 — 
                 ASTM D613 
                 45.0 
               
               
                   
                   
               
             
          
         
       
     
         [0036]    b. colza oil→43.4 
         [0037]    Test Results: 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Test Item 
                 Unit 
                 Test Method 
                 Test Result 
               
               
                   
                   
               
             
             
               
                   
                 Cetane number 
                 — 
                 ASTM D613 
                 43.4 
               
               
                   
                   
               
             
          
         
       
     
         [0038]    c. cotton seed oil→43.4 
         [0039]    Test Results: 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Test Item 
                 Unit 
                 Test Method 
                 Test Result 
               
               
                   
                   
               
             
             
               
                   
                 Cetane number 
                 — 
                 ASTM D613 
                 43.4 
               
               
                   
                   
               
             
          
         
       
     
         [0040]    d. soybean oil→43.7 
         [0041]    Test Results: 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Test Item 
                 Unit 
                 Test Method 
                 Test Result 
               
               
                   
                   
               
             
             
               
                   
                 Cetane number 
                 — 
                 ASTM D613 
                 43.7 
               
               
                   
                   
               
             
          
         
       
     
         [0042]    In the test results, the cetane numbers averaged between 43.4˜45, thus effectively improving the starting capability of diesel oil engines, decreasing the emission of NOX (nitrogen oxide), CO (carbon monoxide), and THC (Total Hydrocarbons), as well as reducing fuel consumption and combustion noise. 
         [0043]    Based on the test results as described above, the derived advantages of the present invention are as follows: 
         [0044]    1. Able to substantially decrease the emission of black smoke and discharge and dispersal of nitrides, as well as being fuel efficient. 
         [0045]    2. Combustion explosiveness is higher and stable. 
         [0046]    3. 100% compatible for direct use in existing diesel engines. 
         [0047]    4. No need to modify the engine system when mixed 50% with general diesel oil or common diesel oil, and improves engine efficiency. 
         [0048]    Furthermore, when the vegetable oil and the alkide (catalyzing enzyme) are proportionally mixed, the higher the flash point, the lower the sulfur content, achieving almost zero sulfur content. And when the flash point is slightly lower, the sulfur content is similarly within a safety range, again achieving almost zero sulfur content. The value of the flash point can be adjusted according to customer requirements to achieve a value within a preferred range. 
         [0049]    It is of course to be understood that the embodiments described herein are merely illustrative of the principles of the invention and that a wide variety of modifications thereto may be effected by persons skilled in the art without departing from the spirit and scope of the invention as set forth in the following claims.