JP2006057921A - Combustion method and device for oil-water mixture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To sufficiently mix an oil with water at a prescribed mixture ratio by only a physical stir, and to excellently combust an oil-water mixture thereof regardless of the mixing of the water to reduce an exhaust amount of air pollutant. <P>SOLUTION: In this combustion method for the oil-water mixture for mixing the oil with water and combusting it, the oil and the water are supplied to a stirring tank 1 at a ratio of 8:2 to 4:6 by a high pressure pump 15, and are stirred in the stirring tank by a stirring means 3 to form emulsified mixed fuel, and the mixed fuel is heated to a temperature of 200-400°C and is sent to a nozzle 28 at a pressure of 10-30 MPa, and is combusted together with heated air. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an oil / water mixture combustion method and apparatus for mixing and burning oil and water.

  Fuel oil (general oil including heavy oil, light oil, kerosene, heavy oil, engine oil, hydraulic oil, gear oil, food oil and similar oils, and waste oil thereof) in general It has long been known that efficient combustion results can be obtained by emulsifying the mixed fuel after adding water to the oil, and more generally burning heavy oil. At that time, there are concerns about the generation of air pollutants (nitrogen oxides, sulfur oxides, carbon monoxide, carbon dioxide, etc.), but it is also known that the generation of these substances can be suppressed with water-added fuel. (Patent Document 1).

  However, in order to use a mixed fuel, multiple factors such as the water / oil mixing ratio of the mixed fuel, the subdivision state of the oil contained in the mixed fuel, the temperature of the mixed fuel, and the diffusion after injection of the mixed fuel are good We must keep a good condition. Conventionally, an example of emulsifying a water / oil mixed fuel by adding an emulsifier such as a surfactant in order to maintain a mixed state of water / oil is generally used (Patent Document 2 as an example). .

In order to obtain a mixed fuel by adding an emulsifier, it is necessary to stir and mix while supplying a certain amount of the emulsifier, and equipment for production is required, and the cost of the equipment and the emulsifier is reflected in the unit price of fuel. Becomes higher.
Japanese Patent No. 3236249 Japanese Patent No. 25595973

  A combustion apparatus for mixed fuel emulsified only by physical agitation without adding the above-mentioned emulsifier has a corresponding effect per se, but it is difficult to sufficiently emulsify, and the emulsified mixed fuel becomes water over time. It was easy to separate into oil and stable fuel supply was difficult.

  The present invention has been made in view of the above points. Oil and water are sufficiently mixed at a predetermined mixing ratio only by physical stirring, and supplied to a combustion nozzle while preventing oil-water separation of the oil-water mixture. Another object of the present invention is to provide a method and apparatus for burning an oil / water mixture that achieves good combustion regardless of the mixing of water so that the amount of air pollutants discharged is as small as possible.

  In order to achieve the above object, the method for combusting an oil / water mixture according to the present invention is an oil / water mixture combusting method for mixing and burning oil and water. The mixture is supplied to the agitation tank at a ratio of 4: 6 and mixed with the emulsification by stirring with the agitation means in the agitation tank. The mixed fuel is heated to a temperature of 200 to 400 ° C. at a pressure of 10 to 30 MPa and sent to the nozzle Burn with heated air.

  Further, the combustion apparatus for an oil / water mixture of the present invention generates a mixed fuel of oil and water by being provided in a stirring tank, a metering pump for feeding oil and water to the stirring tank, respectively, and rotatably provided in the stirring tank. Stirring means, a high-pressure pump for sending the mixed fuel in the stirring tank, a combustion chamber having a nozzle and an air introduction cylinder at one end, one end connected to the high-pressure pump, and an intermediate heating section wound around the peripheral wall of the combustion chamber A fuel supply pipe whose other end is connected to the nozzle, an air supply pipe whose one end is connected to the blower, the intermediate heating section is wound around the peripheral wall of the combustion chamber, and the other end is connected to the air outlet. The high-temperature and high-pressure mixed fuel is injected from the nozzle together with the high-temperature air from the air introduction cylinder into the combustion chamber and burned.

  In addition, a storage tank is attached to the lower part of the stirring tank, and the stirring means supports three turbine-type stirring blades having a disk and a large number of blades extending in the axial direction from the peripheral edge thereof, and supports these stirring blades. The rotating blade has a rotating shaft, and the upper two stirring blades are disposed in the stirring tank, and a plurality of elongated plates are disposed between the two stirring blades, and one stirring blade is stored. It is arrange | positioned in a tank and it can be made to send mixed fuel from a storage tank with a high pressure pump.

In the practice of the present invention, combustion becomes unstable when the temperature of the mixed fuel is 200 ° C. or lower, and there is no change in efficiency even when the temperature is 400 ° C. or higher.
When the pressure is 10 MPa or less, the fuel is not atomized sufficiently and unstable combustion occurs. When the pressure is 30 MPa or more, a problem in mechanical strength occurs.

According to the present invention, water having a predetermined mixing ratio is mixed into the mixed fuel, so that air pollutants in the exhaust gas after combustion of the mixed fuel can be reduced to a very small amount.
Oil and water are mixed only by physical agitation, and can be stably injected and burned from the nozzle while preventing separation of oil and water, without requiring an emulsifier such as a surfactant. The mixed fuel can be burned.

In addition, since the mixed fuel is injected from the nozzle in a high temperature and high pressure state, and heated air is injected from the periphery of the injected fuel, the mixed fuel can be further subdivided and ignited in a high temperature state to perform combustion close to complete combustion. it can.

  An embodiment of an oil / water mixture combustion apparatus according to the present invention will be described with reference to FIGS.

  Reference numeral 1 denotes a cylindrical stirring tank, and oil and water are fed to the stirring tank 1 at a predetermined ratio by metering pumps P1 and P2. A storage tank 2 having a larger capacity than this is provided below the stirring tank 1 as necessary. These metering pumps P1, P2 perform, for example, mechanical interlocking or electrical control in order to make the ratio of the discharge amounts constant.

  Stirring means 3 is provided inside the stirring tank 1 and the storage tank 2. The stirring means 3 is preferably provided with three stirring blades 4 a, 4 b, 4 c and is supported coaxially by the rotating shaft 5. Each of the stirring blades 4a, 4b, 4c has a circular disk 6 and a large number of blades 7 and has a turbine blade shape. Each blade 7 extends bi-directionally (in the drawing) in the axial direction from the peripheral edge of the disk 6 or one of them, and is formed into a polygonal shape such as a substantially trapezoid, a rectangle, or a triangle as viewed from the radial direction.

Two upper stirring blades 4 a and 4 b (reference numeral 4 is used to show the whole) are disposed in the stirring tank 1, and an elongated plate 8 is provided between the stirring blades 4. Another one stirring blade 4 c is arranged in the storage tank 2. A drive motor 9 that rotationally drives the shaft 5 is provided in the upper part of the stirring tank 1, and the lower end of the rotary shaft 5 is rotatably supported by a foot bearing 10.
The uppermost stirring blade 4a is for lowering the mixed fuel downward, and has a structure suitable for such an action.
The second stirring blade 4b enhances the mixing effect and acts to push into the narrow hole H. Due to the narrow hole H, the mixed fuel is mixed with the stirring blade 4b for a relatively long time. The lowermost stirring blade 4c stirs so that oil and water are not separated.

  In the cylindrical stirring tank 1, oil and water are stirred and physically mixed while receiving a shearing force by the stirring blade 4, and are efficiently emulsified to produce a mixed fuel. Then, the mixed fuel is transferred to the storage tank 2 and supplied to a combustion chamber described later while the supply amount is adjusted. By adjusting the volume of the stirring tank 1 to the amount of consumption, generation | occurrence | production of the floating oil which occurs with time can be suppressed. As shown in FIG. 6, the stirring blade 4 has 3 to 8 blades 7 and preferably rotates at about 900 to 1200 times / minute. The stirring by the blades can also prevent the fuel from gelling.

  A discharge pipe 11 is provided below the storage tank 2, and a discharge pipe 12, an ignition oil pipe 13, and a drain pipe 14 are connected to the discharge pipe 11. A high pressure pump 15 is provided in the delivery pipe 12, and the mixed fuel sent from the lower part of the storage tank 2 through the discharge pipe 11 and the delivery pipe 12 is delivered by the high pressure pump 15. Reference numerals 16 to 18 are valve levers for opening and closing each pipe, and 19 is a filter.

  When the combustion chamber is ignited, the associated valve is closed by the valve lever 16 and the valve of the oil pipe 13 is opened by the valve lever 17. Is sent out by the high-pressure pump 15. When the combustion chamber reaches a sufficient combustion temperature after ignition, the valve of the ignition oil pipe 13 is closed by the valve lever 17, the valve of the discharge pipe 11 is opened by the valve lever 16, and the mixed fuel from the storage tank 2 passes through the pipe 11. , 12 through a high-pressure pump 15.

  An air introduction cylinder 22 is provided in the opening 21 in the ignition cylinder portion 20 a at one end of the combustion chamber 20. One end of the heat-resistant air supply pipe 23 is connected to the blower 24, the intermediate heating part 25 is coiled and embedded in the peripheral wall of the combustion cylinder part 20 b of the combustion chamber 20, and the other end is connected to the air introduction cylinder 22. Has been. As a specific example, the peripheral wall of the combustion chamber is formed of, for example, a double-structured combustion cylinder, and the intermediate heating unit 25 is wound around the inner wall in a coil shape and covered with the outer wall.

  The secondary air blown from the blower 24 is heated to a high temperature by the transfer heat such as radiant heat from the combustion cylinder portion 20b of the combustion chamber 20 in the coil-shaped intermediate heating portion 25 of the supply pipe 23, and a vortex generator is generated in the combustion chamber. The fuel 27 is ejected as a vortex by the nozzle 27 and is injected from the nozzle 28 disposed in the front. The amount of secondary air is adjusted by a damper attached to the blower 24.

  A nozzle 28 for injecting fuel is disposed at the center of the tip of the air introduction tube 22. Both ends of the fuel supply pipe 29 are connected to the nozzle 28 and the high-pressure pump 15, respectively. The intermediate heating unit 30 is wound around the peripheral wall of the combustion chamber 20 in the same manner as the intermediate heating unit 25 of the air supply pipe. ing. The mixed fuel fed from the high-pressure pump 15 is heated by the heat transferred from the combustion cylinder portion 20b of the combustion chamber 20 in the coiled intermediate heating portion 30, and is injected from the nozzle 28 into the combustion chamber at a high temperature and high pressure.

  31 is a pilot burner for ignition. In the combustion chamber 20, prior to the combustion of the mixed fuel, propane gas, mineral oil or the like is ignited by the spark plug in the pilot burner 31, and the flame is injected into the combustion chamber. On the other hand, by the operation of the valve lever 17, ignition oil, for example, A heavy oil is supplied from the high pressure pump 15 to the nozzle 28, injected from the nozzle 28, and ignited by the flame from the pilot burner 31.

  When the combustion chamber reaches a high temperature due to the ignition oil, the operation of the valve levers 16 and 17 switches the supply of the ignition oil from the high pressure pump 15 to the supply of the mixed fuel, and the mixed fuel is supplied from the nozzle 28 to the combustion chamber. 20 is injected into the combustion chamber 20 and begins to burn in the combustion chamber 20. At that time, the mixed fuel that has been brought to a high pressure and high temperature by the high pressure pump 15 and the intermediate heating section is instantaneously discharged from the nozzle 28 to the atmosphere, so that it becomes a vigorous jet, which facilitates mixing with the air and enables good combustion. When the inside of the combustion chamber 20 becomes sufficiently high in temperature, combustion of the mixed fuel becomes steady, and the pilot burner 31 is no longer needed. It is preferable to replace the fuel ejection amount with a nozzle having a different nozzle size rather than changing the rotational speed of the high-pressure pump 15.

  Reference numeral 32 denotes a heat load appropriately attached to the end portion of the combustion chamber 20. For example, the boiler 32 can be a hot water heater or a steam generator. Exhaust gas from the combustion chamber passes through the heat load 32 and is then discharged to the outside through an exhaust pipe (not shown). The heat load 32 may be attached to the peripheral wall of the combustion chamber instead of the end portion of the combustion chamber as shown.

Next, an embodiment of an oil-water mixture combustion method according to the present invention will be described.
Oil and water are supplied to the stirring tank 1 at a ratio of 8: 2 to 4: 6 by the metering pumps 1 and 2. In the agitation tank 1, the oil and water are physically or mechanically agitated by the agitation means 3 and emulsified to produce a mixed fuel. The mixed fuel is transferred to the storage tank 2 and delivered to the high-pressure pump 15 while the emulsified state is maintained by the stirring blade 4.

  Next, the mixed fuel is supplied to the nozzle 28 through the fuel supply pipe 29 by the high pressure pump 15 at a delivery pressure of 10 to 30 MPa. Further, the mixed fuel is heated to 200 to 400 ° C. by the heat transferred from the combustion chamber 20 in the intermediate heating portion 30 of the fuel supply pipe 29 wound around the peripheral wall of the combustion chamber 20. In the experiment, good results were obtained in the temperature range of 350 to 380 ° C.

  On the other hand, the air fed from the blower 24 passes through the air supply pipe 23, is heated to the same temperature as the mixed fuel by the heat transferred from the combustion chamber 20 in the intermediate heating section 25, and is introduced into the air introduction cylinder 22. The The air introduced into the air introduction cylinder 22 is swirled by the swirl generator 27 and ejected from the nozzle 28 and is ejected into the combustion chamber while entraining the mixed fuel, thereby promoting the combustion of the mixed fuel.

Waste oil and water were agitated and mixed in the agitation tank 1 to produce a mixed fuel, discharged at high pressure by the high-pressure pump 15, and the high-temperature and high-pressure mixed fuel was combusted in the combustion chamber 20 by the nozzle 28. The ratio of waste oil to water was changed to waste oil 3: water 7, waste oil 5: water 5, waste oil 7: water 3, waste oil 10: water 0, and mixed fuel was produced and burned. The results are shown in Table 1.
Table 1

  As shown in Table 1, in waste oil 3: water 7, waste oil 5: water 5, waste oil 7: water 3, nitrogen oxides and sulfur dioxide are within the standard values of the Air Pollution Control Law. These values are plotted as shown in FIG. 7, and the ratio of waste oil to water is considered to be good when the range of 8: 2 to 4: 6 is obtained. That is, when the amount of waste oil exceeds 80%, the amount of nitrogen oxides and sulfur dioxide increases and it is difficult to suppress the generation of air pollutants. In addition, when the mixing ratio is 3: 7, that is, when the amount of waste oil is 30%, the flame state becomes unstable, and there is no flame problem with heavy fuel oil A, and the combustion state varies depending on the type of oil. Considering these circumstances, the lower limit of the oil is set to 40% or more, and a favorable combustion can be performed by setting the mixing ratio to 4: 6. Also, if the amount of waste oil exceeds 70%, the amount of nitrogen oxides or sulfur dioxide tends to increase. Therefore, it is preferable to reduce the amount of waste oil to 70% or less, and oil other than waste oil contains a relatively small amount of air pollutants than waste oil. Since it contains, it is preferable that the mixing ratio of oil and water shall be 7: 3-4: 6.

Further, carbon monoxide and carbon dioxide are almost completely different from each other even when the mixing ratio of waste oil is 30 to 70%, which is almost 100%.
The internal pressure of the fuel supply pipe 29 was good when it was 20 MPa, but substantially the same result was obtained even when it was changed from 10 to 30 MPa.

  As can be seen from Table 1, it is confirmed that the temperature is about 1000 to 1400 ° C. at a position 1 m away from the nozzle. The flame temperature is physically lowered by mixing water with that of the waste oil at 100%, but exceeds 1000 ° C., and it can be said that it is sufficient to determine the intended use. While the combustion chamber was operating, the smell of combustion gas was sensibly confirmed in the surroundings, but no off-flavor was perceived. This result is presumed that the water portion of the oil / water mixed fuel in the fuel supply pipe behaves as supercritical water at high temperature (200 to 400 ° C.) and high pressure (10 to 30 MPa).

The schematic diagram which shows one Embodiment of the combustion apparatus of this invention. The detailed front view which shows the combustion chamber part of FIG. The detailed front view which shows the stirring tank part of FIG. The figure which follows the BB line of FIG. The figure which shows the stirring means of FIG. The expansion perspective view of the stirring blade of FIG. The graph which shows the combustion result by the combustion method of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Stirring tank 2 ... Storage tank 3 ... Stirring means 4a, 4b, 4c ... Stirring blade 5 ... Rotating shaft 6 ... Disk 7 ... Blade 8 ... Plate 11 ... discharge pipe 12 ... delivery pipe 13 ... ignition oil pipe 14 ... drain pipe 15 ... high pressure pumps 16, 17, 18 ... valve lever 20 ... combustion chamber 21 ... Opening 22 ... Air introduction tube 23 ... Air supply pipe 24 ... Blower 25, 30 ... Intermediate heating part 27 ... Swirl generator 28 ... Nozzle 29 ... Fuel supply pipe

Claims (3)

In the combustion method of an oil / water mixture for mixing oil and water for combustion, oil and water are respectively supplied to a stirring tank at a ratio of 8: 2 to 4: 6 by a metering pump and stirred in the stirring tank. Combustion of an oil-water mixture characterized in that the mixed fuel is agitated and emulsified by means, and the mixed fuel is heated to a temperature of 200 to 400 ° C. at a pressure of 10 to 30 MPa, sent to a nozzle, and combusted with the heated air. Method. An agitation tank, a metering pump that supplies oil and water to the agitation tank, an agitation means that is rotatably provided in the agitation tank and generates a mixed fuel of oil and water, and a mixed fuel in the agitation tank is sent out A high-pressure pump, a combustion chamber having a nozzle and an air introduction cylinder at one end, a fuel supply in which one end is connected to the high-pressure pump, an intermediate heating unit is wound around the peripheral wall of the combustion chamber, and the other end is connected to the nozzle A pipe, one end connected to the blower, an intermediate heating unit wound around the peripheral wall of the combustion chamber, and the other end connected to the air outlet, and a high-temperature high-pressure mixed fuel from the nozzle to the air introduction cylinder An oil / water mixture combustion apparatus for injecting and combusting together with high-temperature air from a combustion chamber. A storage tank is attached to the lower part of the agitation tank, and the agitation means supports and rotates three turbine-type agitation blades having a disk and a large number of blades extending in the axial direction from the periphery thereof. The upper two stirring blades are disposed in the stirring tank, and a plurality of elongated plates are disposed between the two stirring blades. One stirring blade is a storage tank. The oil / water mixture combustion apparatus according to claim 2, wherein the mixed fuel is sent out from the storage tank by a high-pressure pump.

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