WO2008130064A1

WO2008130064A1 - Emulsion fuel manufacturing apparatus using heavy oil and waste oil

Info

Publication number: WO2008130064A1
Application number: PCT/KR2007/001924
Authority: WO
Inventors: Jung-Su Lee
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-04-18
Filing date: 2007-04-20
Publication date: 2008-10-30
Anticipated expiration: 2009-10-18
Also published as: KR20080093812A

Abstract

Disclosed is an emulsion fuel manufacturing apparatus using heavy oil and waste oil, comprising a fuel oil tank for supplying fuel oil, a water tank for supplying water, a mixer for mixing the fuel oil from the fuel oil tank and the water from the water tank, a stirrer for mixing a resultant mixture from the mixer again, and an emulsifier for emulsifying a mixture from the stirrer. The emulsion fuel manufacturing apparatus according to the present invention can manufacture emulsion fuel by mixing heavy oil and waste oil, which is relatively cheap in comparison with gasoline or kerosene, and water. The emulsion fuel manufacturing apparatus can reduce the emission of smoke, resulting in the inhibition of environmental pollution, increase the consumption efficiency of heavy oil by reducing the usage of heavy oil by about 15% through the use of emulsion fuel, exhibiting the same calories generated by fuel manufactured from heavy oil alone, and can use waste oil from cooling oil and lubricating oil, which is used for a variety of machinery.

Description

[DESCRIPTION]

[invention Title]

EMULSION FUEL MANUFACTURING APPARATUS USING HEAVY OIL AND WASTE OIL

[Technical Field]

The present invention relates to an emulsion fuel manufacturing apparatus using heavy oil and waste oil, and more particularly to an emulsion fuel manufacturing apparatus using heavy oil and waste oil (hereinafter referred as "fuel oil") which is capable of increasing heat efficiency and reducing the emission of smoke by adding water to fuel oil at a predetermined ratio.

[Background Art]

Generally, petroleum is refined in a petroleum refinery through a distillation method, in which crude oil is heated to a first predetermined temperature and is then cooled down to a second predetermined temperature, so that lubricating oil, fuel oil, gasoline, kerosene, naphtha and petroleum gas are obtained in turn as products from a high temperature to a low temperature.

Out of the products, fuel oil is about 30 to 50% of the volume of crude oil, and it is classified into A fuel oil, B fuel oil, and C fuel oil based on viscosity. These can be further classified into a plurality of groups based on viscosity, sulfur content, and pour point.

A fuel oil is generally used as fuel in the ceramic industry, metal refineries, and small diesel engines, B fuel oil is generally used as fuel for large diesel engines, and C fuel oil is used as fuel for large-scale boilers, large-scale diesel engines and the steel industry.

C fuel oil is generally called Bunker C oil (also referred to as B-C oil, its short name) , and it is in a solid state and hardly burns at all at a low temperature because it has high viscosity. Accordingly, it is used as furnace fuel in combustion engines of ships, oil-burning power plants, large-scale industry boilers, and iron works.

Such B-C oil (hereinafter, referred to as heavy oil) is relatively cheap in comparison with gasoline and kerosene but has disadvantages in that it has low heat efficiency and causes environmental pollution because it emits smoke containing large amounts of SOx, NOx and dust .

Accordingly, there is a need to study methods of increasing the consumption efficiency of heavy oil, which constitutes a large fragment of crude oil, and of decreasing air pollution by reducing the emission of smoke which is generated when it is used as fuel.

[Disclosure]

[Technical Problem] Accordingly, the present invention has been devised in consideration of the aforementioned problems and conditions, and it is an object of the present invention to provide an emulsion fuel manufacturing apparatus using heavy oil and waste oil for manufacturing emulsion fuel, in which heavy oil and water are stably mixed in order to increase consumption efficiency of heavy oil and inhibit the emission of smoke for the purpose of reducing environmental pollution.

It is a further object of the present invention to provide an emulsion fuel manufacturing apparatus using heavy oil and waste oil, which is capable of recycling waste oil from cooking oil and lubricating oil, which is generally used for machinery.

[Technical Solution] In order to achieve the above described advantageous effects and objects, in accordance with the present invention, there is provided an emulsion fuel manufacturing apparatus using heavy oil and waste oil, comprising a fuel oil tank for supplying fuel oil, a water tank for supplying water, a mixer for mixing the fuel oil from the fuel oil tank and the water from the water tank, a stirrer for mixing again the mixture from the mixer, and an emulsifier for emulsifying the mixture from the stirrer.

The emulsion fuel manufacturing apparatus may further comprise a storage tank for storing emulsion fuel discharged from the emulsifier.

The mixer may comprise a first vessel, the vessel having a first and a second introduction hole, for receiving the fuel oil and the water from the fuel oil tank and the water tank, respectively, a first discharge hole for discharging the mixture to the mixer, a first space which can be filled with the fuel oil and the water, and a first heating means; a first impeller installed in the first space; and a first motor for providing the first impeller with rotational driving force.

The first heating means may comprise a first steam introduction hole and a first steam discharge hole provided at the top end portion and a bottom end portion of a wall of the first vessel, and a first heating pipe arranged along an inner surface of the wall of the first vessel and being disposed between the first steam introduction hole and the first steam discharge hole.

The first vessel may further include a first temperature gauge, which measures the inner temperature of the first vessel, therein for controlling the first heating means, which heats the fuel oil and the water.

The mixer may mix the fuel oil and the water by receiving the fuel oil and the water from the fuel oil tank and the water tank, respectively, at a mixing ratio of 70 weight%:30weight %.

The stirrer may comprise a second vessel having a third introduction hole for receiving the mixture of the fuel oil and the water from the mixture, a second discharge hole for discharging the resultant mixture to the emulsifier, a second space to be filled with the mixture, and a second heating means,- a second impeller installed in the second space; and a second motor for providing the second impeller with rotational driving force.

The second vessel may further include a second temperature gauge, which measures the inner temperature of the second vessel, therein for controlling the second heating means which serves to heat the fuel oil and the water.

The emulsifier may comprise a hollow pipe, which is arranged in a horizontal direction, has a predetermined length, and is hollow; a rotational shaft installed parallel to the back-and-forth direction of flow of the mixture; a driven pulley connected to an end of the rotational shaft; a driving pulley for transferring driving force to the driven pulley via a belt, and a third motor having a shaft connected to the driving pulley.

The hollow pipe may comprise a first guide part, in which depressions are formed on an inner surface of a front portion of the hollow pipe at regular intervals, a protrusion part, in which first protrusions and first depressions are alternately arranged at regular intervals, a second guide part, whose inner diameter increases, the protrusion part and the second guide part being formed at a back portion of the hollow pipe, a fourth introduction hole, through which the mixture from the stirrer is introduced, and a third discharge hole for discharging emulsified fuel.

The emulsifier may comprise a middle portion of the hollow pipe, between the front portion and the back portion, and the middle portion may have through holes.

The rotational shaft may have a plurality of third impellers, which freely rotate in the first guide part, and a plurality of fourth impellers, which rotate in the second guide part and have a plurality of protrusions in a manner such that side surfaces of the second protrusions are in close contact with side surfaces of the protrusions . In the emulsion fuel manufacturing apparatus, a third pipe connected between the mixer and the stirrer may be provided with a valve for controlling the flow of the mixture, a fourth pipe connected between the second discharge hole of the stirrer and a fourth introduction hole of the emulsifier may be provided with a pump for circulating the mixture, and a sixth pipe may branch off a fifth pipe connected between a third discharge hole of the emulsifier and a storage tank by a three-way valve, and may be connected to a return hole of the stirrer, in which emulsion fuel from the emulsifier is circulated between the stirrer and the emulsifier by manipulating the valve provided to the third pipe and the three-way pipe.

[Advantageous Effects]

According to the present invention, it is possible to prepare emulsion fuel which can be used as fuel by mixing heavy oil, which is relatively cheap in comparison with gasoline and kerosene, with water. As a result, it is possible to reduce environmental pollution by inhibiting the emission of smoke. It is also possible to decrease the usage of heavy oil by 15% while still generating the same number of calories of energy.

Still further, since it is possible to use waste oil from lubricating oil and cooling oil as well as to use heavy oil when preparing emulsion oil, the present invention has the advantage of recycling waste oil.

[Description of Drawings]

FIG. 1 is a schematic block diagram illustrating an emulsion fuel manufacturing apparatus using fuel oil according to one embodiment of the present invention;

FIG. 2 is a cross-sectional view illustrating a mixer according to one embodiment of the present invention;

FIG. 3 is a cross-sectional view illustrating a stirrer according to one embodiment of the present invention; FIG. 4 is a cross-sectional view illustrating an emulsifier according to one embodiment of the present invention;

FIG. 5 is a partial perspective view illustrating a pivotal shaft and a hollow pipe, which constitute the emulsifier according to one embodiment of the present invention; and

FIG. 6 is a plan view illustrating an impeller applied to the mixer and the stirrer according to one embodiment of the present invention.

[Best Mode] Hereinafter, an emulsion fuel manufacturing apparatus using heavy oil and waste oil according to one embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic block diagram illustrating an emulsion fuel manufacturing apparatus using fuel oil according to one embodiment of the present invention, FIG. 2 is a cross-sectional view illustrating a mixer according to one embodiment of the present invention, FIG. 3 is a cross-sectional view illustrating a stirrer according to one embodiment of the present invention, FIG. 4 is a cross- sectional view illustrating an emulsifier according to one embodiment of the present invention, FIG. 5 is a partial perspective view illustrating a pivotal shaft and a hollow pipe, which constitute the emulsifier according to one embodiment of the present invention, and FIG. 6 is a plan view illustrating an impeller applied to the mixer and the stirrer according to one embodiment of the present invention.

With reference to FIG. 1 through FIG. 6, the emulsion fuel manufacturing apparatus using heavy oil and waste oil comprises a fuel oil tank 100 for supplying fuel oil 1, a water tank 200 for supplying water 2, a mixer 30 for mixing the fuel oil 1 supplied in the fuel oil tank 100 with water

2 supplied in the water tank 200, a stirrer 300 for stirring a liquid mixture of the fuel oil 1 and the water

2, an emulsifier 500 for emulsifying the liquid mixture by breaking up the liquid mixture, and a storage tank 600 for storing emulsion fuel output from the emulsifier 500.

The elements of the emulsion fuel manufacturing apparatus according to the embodiment of the present invention will be described in detail below.

The fuel oil tank 100 has a predetermined volume and is filled with the fuel oil 1. The fuel oil tank 100 includes a heater (not shown) inside it, so that it can keep the fuel oil 1 therein warm, at about 85°C .

The reason for keeping the fuel oil 1 warm is to lower the viscosity of the fuel oil. That is, fuel oil 1 at a high temperature has high fluidity due to its low viscosity, so that it can be smoothly introduced into the mixer 300.

The water tank 200 is filled with the water 2 and also has a heater (not shown) therein, so that the temperature of the water 2 in the water tank 200 can be maintained at about 85^°C . This has also been devised to increase the fluidity of the water 2. The water 2 in the water tank 200 is mixed with a small amount of emulsifying agent .

The emulsifying agent serves to enable the water 2 and the fuel oil 1 to be easily mixed.

The fuel oil tank 100 and the water tank 200 further include respective temperature gauges (not shown) therein, so that the heaters in the tanks 100 and 200 are preferably controlled to start at a low temperature and stop at a high temperature .

The fuel oil 1 and the water 2, heated to a predetermined temperature, are introduced into the mixer 300.

In this instance, a first pipe 110, connected between the fuel oil tank 100 and the mixer 300, is equipped with a first flowmeter 112, and a second pipe 120, connected between the water tank 200 and the mixer 300, is equipped with a second flowmeter 122.

The mixer 300 primarily mixes the fuel oil 1 and the water 2 containing the emulsifying agent, introduced through the first pipe 110 and the second pipe 120, respectively, at a mixing ratio of 70 weight% to 30 weight% . The mixer 300 has a first space 312 having a first volume therein, a first heating means 320 installed along the inner surface of a first vessel 310 having the cylinder shape, and a first impeller 318 having two layers of cross- shaped blades in a lower center portion of the first space 312. The first impeller 318 is rotated by a first shaft 314 coupled to a coupling unit 360 using driving power from a first motor 330 installed at a lower part of the first vessel 310. The first vessel 310 is supported by a first support member 370.

The first heating means 320 includes a first steam introduction hole 322 and a first steam emission hole 324, provided in an exposed manner at the top and the bottom, respectively, of the wall of the first vessel 310. The first steam introduction hole 322 and the first steam emission hole 324 are connected to respective ends of a first heating pipe 326 on the inner surface of the wall of the first vessel 310. Hot steam is introduced through the first steam introduction hole 322, and is circulated along a hot steam pipe 326 arranged along the inner surface of the wall of the first vessel 310 in the coil form, thereby indirectly heating the fuel oil 1 and the water 2 stored in the first space 312 in the first vessel 310 so that they can be maintained at about 85^°C. Since the first temperature gauge 340 is installed in the first vessel 310, the mixer 300 is controlled in a manner such that the introduction of steam is stopped when the temperature of the fuel oil 1 and the water 2 in the first vessel 312 is higher than 85^°C, and such that the introduction of steam is resumed when the temperature of the fuel oil 1 and the water 2 in the first vessel 312 is lower than 85°C.

The mixer 300 mixes the fuel oil 1 and the water 2 by- circulating the fuel oil 1 and the water 2 containing the emulsifying agent up and down in the first vessel 310 by driving the first motor 330 after the fuel oil 1 and the water 2 are introduced into the first vessel 310 through a first introduction hole 302a and a second introduction hole

302b provided at a top end portion of the first vessel 310.

The liquid mixture primarily mixed in the mixer 300 is discharged through the first discharge hole 304, introduced into the stirrer 400 through a third pipe 130 and a third introduction hole 402 provided to the stirrer 400, and is then mixed again. The stirrer 400 has the same configuration as the mixer 300, and enhances the emulsification efficiency of the liquid mixture and heats the liquid mixture to about 85^°C.

That is, the stirrer 400 has a second space 412 having a predetermined volume and provided in a second vessel 410 having the cylinder shape, a second heating means 420 installed along the inner surface of the second vessel 410, and a second impeller 418 having two layers of cross-shaped blades. The second impeller 418 is rotated by a second shaft 414 coupled to a coupling unit 460 using driving power generated by a second motor 430 installed at a lower part of the second vessel 410. The second heating means 420 includes a second steam introduction hole 422 and a second steam discharge hole 424 provided in an exposed manner at the top and the bottom of the wall of the second vessel 410. The second steam introduction hole 422 and the second steam discharge hole 424 are connected to respective ends of a second heating pipe 426 provided on the inner surface of the wall of the second vessel 410. Hot steam is introduced through the second steam introduction hole 422, and is circulated through the second heating pipe 426, arranged along the inner surface of the wall of the second vessel 410 in a coil shape, thereby indirectly heating the liquid mixture in the second vessel 410 to maintain it at 85^°C.

The second vessel 410 also has a second temperature gauge 440 therein, and the second temperature gauge 440 performs the same function as the first temperature gauge 340 in the mixer 300.

After the liquid mixture, mixed by the mixer 300, is introduced through a third introduction hole 402 provided in the top end portion of the second vessel 410, the second impeller 418, provided in the top end portion of the second shaft 414, is rotated by the second motor 430 to circulate the liquid mixture up and down and mix it again in the second vessel 410.

The liquid mixture mixed by the stirrer 400 is introduced into the emulsifier 500 through a fourth pipe 140 connected to a second discharge hole 404 of the stirrer 400 and a fourth introduction hole 502 provided to the emulsifier 500. The mixture is finely pulverized and emulsified, so that the fuel oil 1 and the water 2 can be more strongly bonded. The mixture in the stirrer 400 is forcibly introduced into the emulsifier 500 by a pump 142 connected to the fourth pipe 140.

The emulsifier 500 comprises a hollow pipe 510 arranged in a horizontal direction and having a predetermined length, a rotational shaft 520 installed in the hollow pipe 510 and oriented in the back and forth direction of the flow of the liquid mixture, a driven pulley 530 connected to an end of the rotational shaft 512, a driving pulley 534 for transferring driving force to the driven pulley 530 via a belt 532, and a third motor 536 having a shaft connected to the driving pulley 534.

In the hollow pipe 510, a first guide part 514, the inner diameter of which increases in order, is installed on the inner surface of the hollow pipe at regular intervals at the front part thereof. A protrusion part 516 in which first protrusions 516a and first depressions 516b, oriented toward the central axis, are alternately arranged at regular intervals, is provided on the inner surface of the back part of the hollow pipe 510. Further, a second guide part518 having inner diameter which increases in order is provided at the back part of the hollow pipe 510. Further, a plurality of third impellers 522 is arranged at a front part 512a of the rotational shaft 520, and blades of the third impellers 522 are installed in a manner such that they can be freely rotated in the first guide part 514. Still further, a fourth impeller 524, having a surface on which second protrusions 524a are formed, is arranged at a back part 512b of the rotational shaft 520 in a manner such that the second protrusions 524a can be rotated in the second guide part 518.

The fourth impeller 524 is rotated in the state in which the side surfaces of the second protrusions 524a, arranged at regular intervals, are in close contact with the surfaces of the first protrusions 516a of the protrusion part 516. At this time, it is preferred that the second protrusions 524a of the fourth impeller 524 be larger than the size of the first depression 516a, so that the liquid mixture flows through the small gap between the second protrusions 514a and the first depressions 516. The second protrusions 524a and the rotational shaft 520 are preferably separately manufactured and are then combined by an additional combining method.

In a middle portion of the hollow pipe 510, between the front part 512a, in which the third impeller 522 is installed, and the back part 512b, in which the fourth impeller 524 is installed, through holes 512c, through which elements in the front part 512a and in the back part 512b can communicate with each other, are formed. The number of through holes 512c is preferably six.

Thanks to the above-described structure, the liquid mixture introduced into the front part of the hollow 512 through the fourth introduction hole 502 of the hollow pipe 510 is mixed again by the third impeller 522 as the rotational shaft 520 is rotated, flows into the back part of the hollow 512 through the through holes 512c, and flows through the gap between the first protrusions 516a and the second protrusions 524a when the contact of the first protrusions 516a and the second protrusions 524 becomes loose while the fourth impeller 524 is rotated. Through the above-described procedure, emulsification of the liquid mixture is promoted, and the emulsified liquid, which is the emulsion fuel, is discharged through the third discharge hole 504.

The emulsion oil discharged from the third discharge hole 504 is in the state of being capable of being used as fuel, and is discharged outside through a discharge hole 156 of a fifth pipe 150, or is introduced into the storage tank 600.

The third pipe 130 is provided with a valve 132 for controlling the flow of the liquid mixture from the mixer 300 to the stirrer 400, and a sixth pipe 160 branches off the fifth pipe 150 of the emulsifier 500 for feedback to the stirrer 400. The branching portion of the fifth pipe 150 is provided with a three-way valve 152.

Thanks to this construction, if the valve 132 is closed, and the three-way valve 152 is manipulated in a manner such that the fifth valve 150, which transfers the emulsion oil to the storage tank 600, is closed and the sixth pipe 160 is opened, the emulsion oil passing out the front part and the back part of the hollow 512 of the emulsifier 500 due to the operation of the pipe 142 is introduced into the stirrer 400 through a return hole 450 of the stirrer 400. This returned emulsion oil can undergo the stirring process and the emulsification process many times, so that the emulsification of the fuel oil is enhanced.

After this repetition of the stirring process and the emulsification process continues for 5 minutes, the fifth pipe 150 is opened and the sixth pipe 160 is closed, so that the emulsion oil from the emulsifier can flow outside or into the storage tank 600.

With reference to FIG. 1 through FIG. 5, the operation procedure of the emulsion fuel manufacturing apparatus using heavy oil and waste oil according to one embodiment of the present invention will be described. First, the fuel oil tank 100 is filled with the fuel oil 1, and then the fuel oil is heated to about 85^°C. The water tank 200 is filled with the water 2, a small amount of emulsifying agent is added to the water 2, and then the water 2 with the emulsifying agent is heated to about 85^°C .

The heated fuel oil 1 and water 2 containing the emulsifying agent are introduced into the mixer 300 at a mixing ratio of 70 weight%:30 weight% . The fuel oil 1 and the water 2 are mixed in the first space 312 of the mixer 300 by the rotation of the first impeller 318, and are then introduced into the stirrer 400 through the first discharge hole 304, maintaining the temperature thereof at 85^°C.

At this time, the mixing ratio is important because the emulsion oil may or may not burn or may be difficult to burn if the relative amount of the water 2 is greater than that of the fuel oil, while the fuel efficiency is low if the relative amount of the water 2 is less than that of the fuel oil.

The stirrer 400 mixes the liquid mixture of the fuel oil 1 and the water 2 again.

The liquid mixture, mixed in the stirrer 400, is then introduced into the emulsifier 500, so that it is finely pulverized and emulsified. Through the emulsification procedure, the fuel oil 1 and the water 2 are more strongly bonded. At this time, the valve 132 provided to the third pipe 130 is closed, and the three-way valve 152 is manipulated in a manner such that the fifth pipe 150, directed to the storage tank 600, is closed, and the sixth pipe 160 is opened, so that the mixture of the fuel oil 1 and the water 2 circulates between the emulsifier 500 and the stirrer 400 for at least five minutes. Thanks to this circulation, emulsification efficiency is enhanced and the produced emulsion oil may exhibit an excellent emulsion property.

After the circulation procedure, the fifth pipe 150 is opened and the sixth pipe 160 is closed, so that the produced emulsion oil passing out the emulsifier 500 is introduced into the storage tank 600.

In the above, the method for producing emulsion oil using fuel oil, such as heavy oil and waste oil, and water is described. In a typical waste oil recycling process, the waste oil must undergo a complicated refinery process in the case in which waste oil from lubricating oil used in a variety of machinery and from cooling oil contains a large amount of moisture. However, even if the waste oil contains a large amount of moisture, the waste oil can be recycled using the emulsion fuel manufacturing apparatus according to the present invention after undergoing only a simple filtration process, in which the waste oil is filtered using a filter to remove impurities. That is, after the removal of impurities, the content of moisture in the waste oil is measured and then a suitable amount of water is added to the waste oil, so that the waste oil can be used to produce emulsion fuel.

Although the present invention has been explained above with reference to the preferred embodiment, the scope of the present invention is not limited to the above- described embodiments, but encompasses substantial equivalents thereof, and furthermore, those skilled in the art will appreciate that various modifications are possible, without departing from the scope and spirit of the invention.

[industrial Applicability]

The present invention relates to an emulsion fuel manufacturing apparatus that uses heavy oil and waste oil, and more particularly to an emulsion fuel manufacturing apparatus that uses heavy oil and waste oil (fuel oil) , which is capable of increasing the heating efficiency of fuel oil by adding water to fuel oil during the production of emulsion fuel, and inhibiting the emission of smoke.

Claims

[CLAIMS]

[Claim 1]

An emulsion fuel manufacturing apparatus using heavy- oil and waste oil, comprising: a fuel oil tank for supplying fuel oil; a water tank for supplying water; a mixer for mixing the fuel oil from the fuel oil tank and the water from the water tank; a stirrer for mixing a resultant mixture from the mixer again; and an emulsifier for emulsifying a mixture from the stirrer.

[Claim2]

The emulsion fuel manufacturing apparatus according to claim 1, further comprising a storage tank for storing emulsion fuel discharged from the emulsifier.

[Claim3]

The emulsion fuel manufacturing apparatus according to claim 1, wherein the mixer comprises: a first vessel having a first and a second introduction hole for receiving the fuel oil and the water from the fuel oil tank and the water tank, respectively, a first discharge hole for discharging the mixture to the mixer, a first space which can be filled with the fuel oil and the water, and a first heating means; any one selected from the group consisting of PP, PE, Pyrex and PMMA.

[Claim4] The emulsion fuel manufacturing apparatus according to claim 3, wherein the first heating means comprises a first steam introduction hole and a first steam discharge hole provided at a top end portion and a bottom end portion of a wall of the first vessel, and a first heating pipe arranged along an inner surface of the wall of the first vessel and disposed between the first steam introduction hole and the first steam discharge hole.

[Claim5]

The emulsion fuel manufacturing apparatus according to claim 3, wherein the first vessel further includes a first temperature gauge, which measures an inner temperature of the first vessel, therein for controlling the first heating means, which heats the fuel oil and the water.

[Claimό]

The emulsion fuel manufacturing apparatus according to claim 5, wherein the mixer mixes the fuel oil and the water by receiving the fuel oil and the water from the fuel oil tank and the water tank, respectively, at a mixing ratio of 70 weight % : 30 weight %.

[Claim7]

The emulsion fuel manufacturing apparatus according to claim 1, wherein the stirrer comprises: a second vessel having a third introduction hole for receiving the mixture of the fuel oil and the water from the mixture, a second discharge hole for discharging a resultant mixture to the emulsifier, a second space to be filled with the mixture, and a second heating means; a second impeller installed in the second space; and a second motor for providing the second impeller with rotational driving force.

[Claim8] The emulsion fuel manufacturing apparatus according to claim 7, wherein the second vessel further includes a second temperature gauge, which measures an inner temperature of the second vessel, therein for controlling the second heating means, which serves to heat the fuel oil and the water.

[Claim9]

The emulsion fuel manufacturing apparatus according to claim 1, wherein the emulsifier comprises: a hollow pipe, which is arranged in a horizontal direction, has a predetermined length, and is hollow; a rotational shaft, installed parallel to a back-and-forth direction of flow of the mixture; a driven pulley connected to an end of the rotational shaft; a driving pulley for transferring driving force to the driven pulley via a belt, and a third motor having a shaft connected to the driving pulley.

[Claim 10]

The emulsion fuel manufacturing apparatus according to claim 9, wherein the hollow pipe comprises: a first guide part, in which depressions are formed on an inner surface of a front portion of the hollow pipe at regular intervals, a protrusion part, in which first protrusions and first depressions are alternately arranged at regular intervals, a second guide part, whose inner diameter increases, the protrusion part and the second guide part being formed at a back portion of the hollow pipe, a fourth introduction hole, through which the mixture from the stirrer is introduced, and a third discharge hole for discharging emulsified fuel.

[Claim ll] The emulsion fuel manufacturing apparatus according to claim 10, wherein the emulsifier comprises: a middle portion of the hollow pipe, between the front portion and the back portion, has through holes.

[Claim 12] The emulsion fuel manufacturing apparatus according to claim 10, wherein the rotational shaft has a plurality of third impellers which freely rotate in the first guide part, and a plurality of fourth impellers which rotate in the second guide part and have a plurality of protrusions in a manner such that side surfaces of the second protrusions are in close contact with side surfaces of the protrusions .

[Claim 13] The emulsion fuel manufacturing apparatus according to claim 1, wherein a third pipe, connected between the mixer and the stirrer, is provided with a valve for controlling flow of the mixture, a fourth pipe connected between the second discharge hole of the stirrer and a fourth introduction hole of the emulsifier is provided with a pump for circulating the mixture, and a sixth pipe branches off a fifth pipe, connected between a third discharge hole of the emulsifier and a storage tank by a three-way valve, and is connected to a return hole of the stirrer, in which emulsion fuel from the emulsifier is circulated between the stirrer and the emulsifier by manipulating the valve provided to the third pipe and the three-way pipe.