Patent Publication Number: US-6702568-B1

Title: Method of burning emulsion fuel oil

Description:
RELATED U.S. APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     REFERENCE TO MICROFICHE APPENDIX 
     Not applicable. 
     FIELD OF THE INVENTION 
     The present invention pertains to methods of burning emulsion fuel oil. More specifically, the present invention is directed to a burning method of water-in-fuel oil emulsion, which is advantageous in terms of excellent combustion efficiency and fuel saving effect, by selectively burning only a portion having excellent emulsification state and high heat efficiency among emulsion fuel oil comprising a fuel oil additive composition mixed with water, while the emulsification state of the fuel oil is maintained at a desired level, by means of a circulating system including a stirrer and a vertical heating bath connected thereto. 
     BACKGROUND OF THE INVENTION 
     With the expectation of future petroleum shortages, there have been proposed various methods for increasing heat efficiency by improvement of boilers or other fuel treating devices, and modification of oil. In addition, there are provided methods for increasing combustion efficiency and decreasing emission of pollutants, in particular, air pollutants, by using combustion enhancers or passing fuel oil through a magnetic field. However, such methods have limited effect on heat efficiency and prevention of air pollution. 
     Further, modified oil obtained by adding a fuel oil modifying composition consisting mainly of siloxane to fuel oil is increased in combustion efficiency and prevents air pollution, but is low in fuel saving effect. 
     BRIEF SUMMARY OF THE INVENTION 
     Therefore, it is an object of the present invention to alleviate problems encountered in the prior art and to provide a method of burning emulsion fuel oil having advantages of excellent combustion efficiency and high fuel saving effect, by stirring the emulsion fuel oil comprising a fuel oil additive composition mixed with a predetermined amount of water by means of a stirrer capable of cutting the fuel oil to fine particles, to obtain emulsion fuel oil having uniformly cut particles, among which emulsion fuel oil having the most preferable emulsification state is selectively burned while the oil emulsification state is continuously maintained at a desired level. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 schematically shows a layout of a circulating system used in a burning method of an emulsion fuel oil according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Based on the present invention, a fuel oil additive composition is mixed with a predetermined amount of water by means of a stirrer, to obtain emulsion fuel oil of excellent emulsification state, among which emulsion fuel oil of better emulsification state is selectively burned while the emulsion fuel oil is continuously maintained at a desired emulsification state by use of a circulating system comprising a vertical heating bath connected to the stirrer. Thus, the present method has the advantages of increased combustion efficiency and fuel saving effect. 
     As for a preparation of the fuel oil additive composition of the present invention, 300 parts by weight of fine coal powders, 50 parts by weight of a saturated magnesium chloride solution, 100 parts by weight of soda and 500 parts by weight of sea water are mixed together and homogenized, followed by passing the homogenized liquid mixture through a catalyst tower packed with uranium ore maintained at 90-95° C. for 10 minutes. 
     Then, the liquid mixture passed through the catalyst tower is filled to be half of the coke height in a retort having a packed coke bed, in which bunker C oil is filled in the same amount as the filled liquid mixture according to a volume ratio. The liquid mixture and oil filled in the retort are heated at 95-100° C. until most salt water (85% or more) is evaporated, to obtain a colloidal liquid remainder. 
     2-4 vol % of the colloidal liquid remainder is added to 96-98 vol % of a mixed oil comprising light oil and bunker C oil at a volume ratio of 1:4 with stirring, thereby preparing the fuel oil additive composition. 
     As such, salt water (liquid mixture) has a specific gravity of 1 or higher, while bunker C oil has a specific gravity of less than 1. Thus, such water and oil components define boundary therebetween. A heterogeneous two-liquid phase is simultaneously in contact with cokes in the retort, and heated under normal atmosphere. 
     The colloidal liquid remainder is composed mainly of bunker C oil, water and carbon particles, with a very small amount of an inorganic material contained in tar-salt water. In such colloidal liquid remainder, magnesium chloride and soda are dissolved in water, and water, bunker C oil particles as well as other component particles are tightly adsorbed around fine carbon particles having high adsorptivity. Hence, phase-separation does not occur and the remainder is present in a colloidal state. 
     As the used carbon materials, black charcoal for a coal lamp may be used, but porous cokes are most preferable in view of large surface area, high strength, low breakage, easy separation from liquid phase after treatment, and easy workability. 
     Thusly obtained additive composition is mixed with 40-50 wt % of water and stirred by use of a stirrer A shown in FIG. 1, thereby preparing the emulsion fuel oil. 
     According to the burning method of the emulsion fuel oil having excellent combustion efficiency and fuel saving effect, the fuel oil composition is mixed with 40-50 wt % of water and sufficiently stirred by use of the stirrer A of FIG. 1, to obtain the emulsion fuel oil, which is then burned under the most effective combustion state. For that, while the fuel oil fed into a cylindrical vertical heating bath B is stabilized at 70-80° C. for a long time, emulsion fuel oil obtained from a middle layer of the vertical heating bath is burned. 
     Referring to FIG. 1, there is shown a circulating system comprising the stirrer A and the vertical heating bath B. In the stirrer A, a rotating shaft A 3  which is connected to a motor A 2  above a top portion of a funnel-shaped body A 1  is connected to a rotating bearing A 5  formed at a center portion of a horizontal bottom portion A 4  of the body A 1 , and rotated. On the vertical rotating shaft A 3  of a position passing through a small-diameter lower part A 6  of the body A 1 , there is positioned a propeller A 7  comprising four slantingly bent blades A 7 ′, under which another propeller A 8  comprising four blades A 8 ′ fixed horizontally to the rotating shaft A 3  is disposed. At one side of the upper portion of the body A 1 , an inlet pipe A 9  and a pump A 9 ′ for feeding the fuel oil additive composition and water into the stirrer are provided. At the opposite side thereof, an inlet pipe A 10  of heterogeneous emulsion fuel oil flowing from a vertical heating bath B is disposed, below which an outlet pipe A 11  of the emulsion fuel oil is provided. A pump A 14  is mounted to the outlet pipe. Further, a first water surface sensor A 12  and a second water surface sensor A 13  are attached to inner wall face of the body A 1 . 
     In the stirrer, the propeller has very sharp blades and is rotated at 3,600 rpm. The lower part of the body A 1  is designed to have a small-diameter, with the aim of fast rotation due to reduced rotation resistance, and of decreasing a motor load. The sharp blade functions to produce many fine particles per unit time at a fast rotation rate. 
     When the propeller A 7  is rotated in the stirrer body A 1  together with the rotating shaft A 3 , the liquid mixture therein is rotated according to arrows represented in the drawing. The lower propeller A 8  comprises horizontally very sharp blades A 8 ′ with no blade angle, and functions to cut the stirred mixture led towards a center portion A 5  of the small-diameter lower part under high pressure while being rapidly rotated. Such a stirrer has various functions of uniformly mixing at least two materials, reducing the homogeneous mixture to a particle size of 2 μm, and homogenizing the particle size. Thereby, the emulsion fuel oil has excellent burning function. 
     The emulsion fuel oil, which is sufficiently stirred and finely cut by means of the stirrer A, is fed into the vertical heating bath B comprising an external cylinder B 1  and an internal cylinder B 2 . Water is charged at a space between the cylinders, and a heating unit B 3  is positioned at a bottom portion of the external cylinder B 1 . At one side of a lower inner face of the internal cylinder B 2 , a certain pipe extended from the outlet pipe A 11  of the stirrer A is perforated through the external cylinder B 1 , to form an inlet B 4 . At the opposite side thereof, an outlet B 5  is formed and extended to a pipeline B 5 ′ that is circulated to the stirrer A. Another outlet B 6  is formed at one side of a middle inner wall of the internal cylinder B 2  and is extended to a pipeline B 6 ′ connected to a boiler C. Also, a further outlet B 7  is formed at one side of an upper inner wall of the internal cylinder B 2  and is extended to a pipeline B 7 ′ circulated to the stirrer A. Sensors B 8  and B 9  sensing oil surface are attached to positions higher than the outlet B 7 . The member numbers B 10  and B 11  are assigned to pumps. 
     When the pump A 14  is operated by a control box B 12 , the emulsion fuel oil flows in the internal cylinder through the inlet B 4 . When the oil surface reaches the sensor B 8 , the operation of the pump A 14  is stopped and concurrently the pump B 10  and the pump B 11  are operated, whereby the emulsion fuel oil positioned at the middle layer of the internal cylinder is fed to the boiler C through the outlet B 6  and the pump B 10 . Also, the pump B 11  functions to introduce heterogeneous emulsion oil of the upper and the lower layers flowing from the outlet B 5  and the outlet B 7  into the stirrer A. When oil surface of the vertical heating bath is gradually decreased and reaches the sensor B 9 , operation of the pump B 11  is stopped and the pump A 14  is again operated, whereby the emulsion fuel oil is fed to the vertical heating bath B. After oil surface of the stirrer A reaches the sensor A 13 , the pump A 9 ′ is operated and a mixture of the fuel oil additive composition and water is stirred by a first stirrer (not shown) and thusly stirred emulsion fuel oil is introduced into the stirrer A through the pipe A 9 . When the oil surface reaches the sensor A 12 , the operation of the pump A 9 ′ is stopped. 
     The emulsion fuel oil filled in the internal cylinder B 2  of the vertical heating bath B is not obviously divided to upper, middle and lower-layer oil. In the lower-layer portion, a water-content is relatively high, while an oil-content is relatively high in the upper-layer portion. In the middle layer portion, a content ratio of oil to water is similar to a mixing ratio of a fuel oil additive composition and water. Such division is provided for convenience. Particularly, homogeneous emulsion fuel oil of the middle layer portion, which is excellent in emulsification state, is burned, thereby achieving superior heat efficiency and fuel saving effect. 
     As for the burning method of the present invention, the fuel oil additive composition having excellent emulsification function is mixed with 40-50 wt % of water, to give the emulsion fuel oil, which is emulsified by use of the stirrer capable of being rapidly rotated at 3600 rpm and uniformly cutting fine particles of 2 μm. Thusly emulsified fuel oil is fed into the cylindrical vertical heating bath B maintained at 70-80° C., whereby only the middle layer portion of the 3-layer emulsion fuel oil is selectively burned. Meanwhile, the upper and lower layer portions are further circulated to the stirrer A, stirred together with emulsion fuel oil newly fed from the pipe A 9 , and again circulated to the heating bath B. While the emulsion fuel oil is repeatedly stirred and circulated, it is burned. 
     In other words, through the present method, the emulsion fuel oil of excellent emulsification state is obtained, which comprises the fuel oil additive composition having excellent emulsification function mixed with water by means of the high functional circulating system. Then, while the emulsification state of such fuel oil is maintained as it is, only a portion having excellent emulsification state is selectively burned, whereby combustion efficiency and fuel saving effect are maximized. 
     With the aim of confirming the effect of the present invention, 55 wt % of fuel oil additive composition was mixed with 45 wt % of water and burned, by use of the circulating system comprising a stirrer A and a vertical heating bath B. The above experiment was performed for 6 months. As a result, fuel oil savings amounted to 23-25% in terms of fuel cost, exclusive of costs required for preparation of fuel oil additive composition, for preparation of emulsion fuel oil and for operation of stirrer A and vertical heating bath B and burning of the fuel oil. 
     As described above, according to the method of the present invention, the fuel oil additive composition is mixed with water, to obtain the emulsion fuel oil which is superior in its homogeneity and has very fine particles using the stirrer. In addition, emulsion fuel oil of excellent emulsification state is selectively burned while emulsification state of the fuel oil is maintained at a desired level, thereby achieving excellent combustion efficiency and fuel saving effect. 
     The present invention has been described in an illustrative manner, and it is to be understood that the terminology used is intended to be in the nature of description rather than of limitation. Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, it is to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.