KR101049715B1 - A hot air fan - Google Patents

Abstract

The present invention relates to a hot air fan for heating by heating and supplying external cold air, and particularly relates to a hot air fan having a complete combustion of oil as a fuel and improving combustion efficiency.

To this end, an embodiment of the present invention includes a combustion chamber and a heating chamber formed at a lower portion, a main body having a fan at one side of the heating chamber, and a hot air outlet at the opposite side thereof, and the combustion chamber inside the heating chamber. A communication unit configured to communicate with each other and to be drawn out to the outside, a burner having a discharge part fixed to the side wall of the combustion chamber and discharged from the mixed gas in which oil and primary air are discharged to protrude into the combustion chamber, and around the discharge unit. A ignition device, a duct pipe protruding from the discharge portion, a red light tube provided in the interior of the duct pipe through a fixing means, in contact with the flame generated from the discharge portion, and in contact therewith, and a lower portion of the discharge portion side. It is provided to communicate with the outside through the lower plate of the combustion chamber, and includes an auxiliary duct to adjust the opening and closing degree through the flow rate adjusting means.

Boiler, red tube, complete combustion

Description

Hot air fan {hot-air supplier}

The present invention relates to a hot air fan for heating by heating and supplying external cold air, and particularly relates to a hot air fan having a complete combustion of oil as a fuel and improving combustion efficiency.

A hot fan is a device that supplies air for heating by heating air with combustion heat obtained by burning a fuel. At this time, the fuel used is operated by using solid fuel such as coal or using more efficient oil.

These fuels, such as petroleum, have a limited amount of resources, and as their production decreases, their costs increase and the operating costs of the boilers increase, putting economic burdens on users.

Petroleum fuel, which is mainly used to obtain high combustion heat, prevents the combustion of the gas which is burned by soot if it is not completely burned, resulting in poor combustion efficiency and shortening the life of the hot air fan. In addition, due to incomplete combustion, a large amount of harmful gases including carbon monoxide harmful to the human body is emitted, causing pollution to the environment.

This disadvantage of incomplete combustion is more severe when using a fuel that is difficult to completely burn, for example bio-oil (bio-oil).

Bio-oil is obtained from animals or plants such as waste cooking oil and palm oil as a combustion fuel that replaces petroleum, and can be obtained inexpensively from foods that are buried and disposed of. However, when such a bio-oil is used for combustion, foreign matters are easily included in the purification process, and the bio-oil itself also has a technical problem that is difficult to obtain complete combustion because its properties are easily changed due to oxidation. In addition, the bio oil has a high viscosity, difficult combustion conditions, and if not completely burned, a large amount of soot is generated to block the passage of the boiler combustion chamber and the exhaust gas to reduce the overall efficiency.

Therefore, it is urgent to develop a hot air blower that completely burns various fuels, including conventional petroleum raw materials and recycled biofuels that are difficult to burn completely.

The present invention has been made to solve the above-described problems, the embodiment of the present invention has the object of making the complete combustion of oil in the combustion chamber of the hot air blower.

More specifically, the oil is burned under high temperature conditions, and the flame is formed to have a long length to achieve complete combustion by increasing the combustion space.

In addition, the purpose of the flow of the additional air for the complete combustion in the combustion chamber to control the flow rate according to the combustion process quickly.

In addition, the purpose of the combustion of the oil is divided into two stages by the additional mixing of air for complete combustion.

In addition, even if bio-oil which is difficult to burn completely, it has the purpose of enabling complete combustion.

In addition, it has the purpose of quickly discharging the mixed gas burned in the combustion chamber in order to form a long flame.

It also has the purpose of allowing the mixing of the added air and combustion gases to take place effectively.

In order to solve the above problems, the present invention includes a combustion chamber and a heat generating chamber formed on the upper side, the main body is provided with a fan on one side of the heat generating chamber and the hot air outlet on the opposite side of the heat generating chamber, A communication unit configured to communicate with the combustion chamber to be drawn out to the outside, a burner having a discharge part fixed to the combustion chamber and discharged to discharge a mixed gas mixed with oil and primary air, protruding into the combustion chamber; An ignition device provided around the discharge part, a duct tube protruding from the discharge part, a red heat tube provided in the interior of the duct pipe through fixing means, in contact with and glowing with the flame generated from the discharge part; The lower part of the discharge part side is provided to communicate with the outside through the lower plate of the combustion chamber, and includes an auxiliary duct for adjusting the opening and closing degree through the inflow amount adjusting means. It presents a yeolpunggi characterized in that.

In addition, the glowing tube has an inner diameter larger than the outer diameter of the discharge portion, the inner end is provided to be spaced apart to the outside of the discharge portion, the secondary air required for combustion between the circumference of the discharge portion and the inner end of the glowing tube. It is proposed a hot air blower, characterized in that the secondary air inlet space is introduced to the front of the discharge portion is formed in the center.

In addition, the auxiliary duct presents a hot air fan, characterized in that the secondary air is provided to be biased to the side around the duct tube so that the secondary air can be introduced while causing the vortex.

In addition, the fixing means is a hot air blower, characterized in that the ribs formed by the air flow path around the inner tube of the duct tube by interconnecting the inner side of the tube.

In addition, the inflow rate adjusting means presents a hot air blower, characterized in that the damper for adjusting the flow rate of the secondary air by adjusting the angle of the opening and closing plate by the drive of the motor.

In addition, the oil suggests a hot air blower, characterized in that the vegetable oil or animal oil.

In addition, the cross-sectional area of the glowing tube, the hot air blower is characterized in that it gradually becomes narrower toward the flame discharge port from the discharge portion, so that the discharge speed of the combustion gas increases.

In addition, the end of the glowing tube presents a hot air blower characterized in that the jaw is further formed to protrude inward to form a vortex.

According to the hot air blower according to the embodiment of the present invention as described above, the heated red tube heats the mixed gas flowing from the discharge portion of the burner to be ignited early, and in addition to the length of the red tube, inflow of the secondary air As a result, the total length of the flame in which the combustion occurs in the mixed gas is further increased, thereby securing time for the oil to be burned, and since the primary combustion gas is burned at a high temperature by the red tube, complete combustion occurs. Therefore, the efficiency of the hot air blows up and the generation of soot by incomplete combustion is suppressed.

On the other hand, as the secondary duct is provided with more secondary air, the oil can supply enough oxygen to completely burn the oil, and the secondary air prevents overheating of the discharge part and the red tube, thereby increasing the life of the product. Has an effect.

In addition, the damper provided in the auxiliary duct is closed at the initial start of the hot air blower, and when the flame is stable, the secondary air is supplied to have the above-described effect, thereby enabling the optimum operation of the boiler.

In addition, the auxiliary duct is formed to be biased, and as the secondary air forms a vortex, the discharge speed of the primary air and the secondary air passing through the air flow path can be increased, thereby making the flame in the combustion chamber longer. It has an effect that can effectively cool the overheat of the discharge portion and the red tube.

On the other hand, even when the bio oil is used as a configuration for the complete combustion, the complete combustion is possible has the effect of using an environmentally friendly fuel.

On the other hand, if the cross-sectional area of the glowing tube is formed to gradually decrease, the discharge rate of the primary combustion gas is increased to form a longer flame has the effect that complete combustion is better.

In addition, when the jaw is further formed at the inner end of the red tube, vortices are generated in the primary combustion gas passing through the discharge port, and are easily mixed with the secondary air passing through the air passage to effectively complete combustion in the secondary combustion gas. Has an effect.

Due to the complete combustion of the oil, the combustion efficiency is increased to enable the operation of an effective hot air blower with less oil, and the exhaust gas due to the complete combustion has an environmentally friendly effect due to less concern for environmental pollution.

Hereinafter, with reference to the preferred embodiment of the accompanying drawings, it will be described in detail the function, composition and operation of the present invention hot air.

In the drawings, the solid arrows indicate the flow of secondary air, and the dashed arrows indicate the flow of the mixed gas.

1 is a block diagram of a hot air fan according to an embodiment of the present invention, Figure 2 is a side cross-sectional view showing the main portion of the main body employed in the hot air fan shown in Figure 1, Figure 3 is an enlarged side cross-sectional view of B of FIG. However, reference numeral 2 is a storage tank containing oil.

The hot air blower 100 according to a preferred embodiment of the present invention includes a combustion chamber 11 and a heat generating chamber 12 formed at the lower and upper portions thereof, and a fan 121 is provided at one side of the heat generating chamber 12 and the hot air at the opposite side thereof. A main body 1 having a discharge port 122, a communication 123 provided to be communicated with the combustion chamber 11 in the heat generating chamber 12 and withdrawn to the outside, and a side wall of the combustion chamber 11. A burner 13 having a fixed and discharged portion 131 through which the mixed gas mixed with oil and primary air is discharged protrudes into the combustion chamber 11, and an ignition provided around the discharge portion 131. Means 132, the duct pipe 14 protruding from the discharge portion 131, and through the fixing means 151 inside the duct pipe 14 is generated from the discharge portion 131 The glowing tube 15 is in contact with the flame is glowing and the lower portion of the discharge portion 131 side passes through the lower plate 111 of the combustion chamber 11 to communicate with the outside. There is provided, and with a secondary duct 16 which is opened and closed degree is adjusted by the flow rate adjusting means (161).

At this time, the oil is produced through a refiner (3) in which the oil is refined, and an atomizer (4) for atomizing the purified oil by various methods such as heating and evaporation. In addition, the primary air mixed with the oil supplied to the burner 13 is introduced into the burner 13 by an air supply 5 composed of a conventional blower.

On the other hand, the burner 13 provided in the combustion chamber 11 mixes atomized oil and primary air to generate a mixed gas in an easy ignition state, and introduces the ignition means 132 into the combustion chamber 11. To ignite the mixed gas. Thereafter, the complexed mixed gas stays in the combustion chamber 11 for a sufficient time to complete combustion.

After combustion is performed, as shown in FIG. 2, after passing through the heat generating chamber along the communication 123 provided on the upper side, the fan is exhausted to the outside of the hot air fan 100, and a fan provided at one side of the heat generating chamber 12. After raising the temperature of the air forcibly passing through the heat generating chamber 12 by the 121, the air space is discharged to the hot air outlet 122 provided on the opposite side of the heat generating chamber 12 to discharge an indoor space such as a botanical garden or a plastic house. It is warming.

Additional configuration of the hot air fan 100 having such a configuration is as follows.

The additional construction described below assumes that the oil is recycled bio oil. First, the refiner 3 removes foreign substances such as debris and impurities contained in bio-oil consisting of vegetable oil such as waste cooking oil, palm oil, soybean oil, or animal oil obtained from subcutaneous fat or fish of an animal.

To this end, the purifier 3 is formed of a plurality of filter layers to sequentially remove residues in the bio oil by size, a cyclone method or a sediment which removes foreign matter collected at the center of rotation and removes suspended matters during rotation by stirring. The bio-oil can be purified by using or combining any of the precipitation methods in which the foreign matter is settled and then removed. In addition to this, various purification methods for chemically and physically removing impurities such as organic matter included in bio oil which are generally discarded may be dedicated.

In addition to the refiner 3, additives of bio oils generally used, such as emulsifiers such as surfactants for lowering the high viscosity of bio oils, or catalysts such as oxidation catalysts for promoting combustion and facilitate combustion. Additive mixer (not shown) for mixing the may be more rough.

On the other hand, the atomizer 4 is to spread the bio oil into small particles in the air so that it can be easily burned by increasing the surface area of the bio oil and increasing the contact surface with the air.

To this end, the atomizer 4 may be a method of forcibly atomizing by spraying bio oil at high pressure in a nozzle (not shown) with a small diameter or a method of inducing natural vaporization by heating to a high temperature.

In this case, when the bio oil recycles the foreign material contained in the raw material itself, such as waste cooking oil, the nozzle may be blocked by the fine foreign matter remaining after the purifier 3, so that the latter is atomized by natural vaporization by heating the bio oil. The manner is preferred. That is, the atomizer 4 wraps a heating wire having high electrical resistance in the passage through which the bio oil is distributed, connects a power source to increase the temperature of the bio oil, and vaporizes the vaporized bio oil obtained by evaporation from the heated bio oil in a liquid state. It is separated from the phosphorus biofuel and introduced into the burner (13). At this time, the liquid and gas separation may be used a gas-liquid separator (not shown) using a conventional cyclone principle.

On the other hand, the vaporization of the bio-oil may be made inexpensively by utilizing the communication 123 discharged after the mixed gas is burned. That is, it is possible to reduce the consumption of power consumed in the heating wire by recovering the waste heat exiting the combustion chamber 11 and recycling the vaporized bio-oil in the atomizer 4.

For this purpose, the pipe from which the bio oil is discharged from the refiner is connected to the atomizer after passing through a heat exchanger for communication and heat exchange, and the atomizer can be configured to vaporize the bio oil with less power by further heating the already heated bio oil with a heating wire. Can be.

With such a configuration further, if the combustion chamber and the heating chamber described above are provided in the hot air fan using the bio oil, complete combustion of the bio oil is possible.

On the other hand, the burner 13 provided on the side wall of the combustion chamber 11 generates a mixed gas in which the vaporized oil and the primary air delivered from the air supply 5 are mixed, and then the combustion chamber 11 through the discharge part 131. It flows inside.

At this time, the burner 13 is provided with a fluid pump (not shown) to introduce the mixed gas into the combustion chamber 11 while maintaining a constant pressure, the ignition means 132 for the initial ignition around the discharge portion 131 ) Is further provided. This ignition means 132 has a conventional configuration for generating an arc to ignite the mixed gas.

One end is connected to the discharge part 131 to the discharge part 131 of the burner 13 to completely burn the oil desired by the present invention, and the other end is an open flame through which the primary combustion gas from which the mixed gas is combusted is discharged. Cylindrical duct pipe 14 having a discharge port 153 formed therein, and a red heat pipe for guiding the primary combustion gas, which is spaced apart from the discharge part 131, to the flame discharge port 153 inside the duct pipe 14. 15 is provided.

At this time, one end of the duct pipe 14 surrounds the periphery of the discharge part 131 so that the discharge part 131 protrudes therein, and the other end has a cylindrical shape which opens the combustion chamber 11 toward the inside.

In addition, the glowing tube 15 is formed in a cylindrical shape along the cylindrical inner surface of the duct pipe 14, so as not to be in direct contact with the discharge portion 131 protruding into the duct pipe 14, The inner end 156 is positioned to be spaced apart from the outside of the discharge part 131.

As a result, the secondary air inflow space S for introducing secondary air, which will be described later, required for combustion, to the center front of the discharge part 131, between the circumference of the discharge part 131 and the inner end circumference of the glowing tube 15. ) Is formed.

In addition, the inner diameter L2 of the discharge portion 131 side of the red heat pipe 15 is larger than the outer diameter L1 of the discharge portion 131, so that the mixed gas flowing in the discharge portion 131 is smoothly glowing. It is preferable to allow the inside of the pipe 15 to be guided, and to allow the secondary air described later to mix well with the mixed gas.

At this time, the inner space of the glowing tube 15 is a space through which the first combustion gas first ignited by the ignition means 132 combusts and passes through during the initial startup of the hot air blower 100. Thereafter, the primary combustion gas exits the flame discharge port 153 and is mixed with secondary air passing through the air passage described later in the combustion chamber 11 to become secondary combustion gas which is further combusted.

On the other hand, the lower part of the discharge portion 131 side of the duct pipe 14 is provided to communicate with the outside through the lower plate of the combustion chamber, the auxiliary duct 16 is adjusted through the inflow amount adjusting means 161 is adjusted Included.

At this time, the secondary duct 16 is in communication with the outside is connected to the air supply (5) is to be a passage through which the secondary air required to complete combustion into the combustion chamber.

In addition, the inlet of the auxiliary duct 16 of the inner duct pipe 14 provided with the discharge part 131 is directed toward the protruding side surface 131b of the discharge part 131 provided inside the duct pipe 14. It is formed on the outer circumferential surface.

On the other hand, the glowing tube 15 is fixed through the inner wall and the fixing means 151 of the duct pipe 14, the fixing means 151 is the inner side of the duct pipe 14 and the outer side of the glowing tube 15 Interconnected ribs form an air passage 154 through which secondary air passes around the glowing tube 15.

As a result, the secondary air flowing into the auxiliary duct 16 surrounds the discharge part 131 of the burner 13, and then a part of the secondary air passes through the secondary air inflow space S and is further mixed with the mixed gas, thereby allowing the red light tube 15 to flow. It is introduced into the interior of the remaining through the air flow path 154 and exits to the flame discharge port (153).

At this time, the inflow amount adjusting means 161 provided in the auxiliary duct 16 is composed of a damper 161 for adjusting the inflow amount of the secondary air by adjusting the angle of the opening and closing plate 161b by the driving of the motor 161a, It is desirable to be able to automatically adjust the amount of secondary air for complete combustion in accordance with the manual operation or the amount of mixed gas discharged from the burner 110.

In addition, the auxiliary duct 16, as shown in Figure 4, may be formed to be laterally circumferentially around the duct pipe 14 so that the secondary air to form a vortex inside the duct pipe (14). .

That is, as the auxiliary duct 16 is not connected to the center of the duct pipe 14 having a cylindrical cross section, the secondary air is rapidly rotated along the side of the discharge portion 131, and further the red heat pipe 15 Rotates along the inner wall or the outer wall of the glowing tube 15 in the interior and the air flow path 154 of the exit to the flame discharge port 153, so that the introduced secondary air can move smoothly inside the duct pipe 14 It is.

On the other hand, Figure 5 is a side cross-sectional view showing the main portion of the combustion chamber and the burner employed in the hot air according to another embodiment of the present invention.

The cross-sectional area of the glowing tube 15 may be gradually narrower from the discharge portion 131 to the flame discharge port 153 so that the discharge speed of the primary combustion gas in the glowing tube 15 is increased. That is, the red heat pipe 15 is gradually narrowed away from the discharge portion 131, so that the discharge speed of the primary combustion gas increases.

That is, as the cross sectional area of the glowing tube 15 gradually decreases, the mixed gas and the secondary air introduced from the discharge part 131 and the auxiliary duct 16 pass through a small cross sectional area, and thus the discharge speed from the flame discharge port 153 is reduced. It becomes faster and can have the length of the flame formed by secondary combustion gas long enough, and it becomes possible to ensure the long flame for complete combustion.

Further, at the end of the glowing tube 15 near the flame discharge port 153, a jaw 155 protruding toward the center of the glowing tube 15 is further formed, and turbulence occurs in the primary combustion gas, and the flame discharge port 153 is formed. You can make it pass.

As a result, the primary combustion gas and the secondary air are easily mixed in front of the flame discharge port 153, so that further combustion is likely to occur.

Hereinafter, the operation of the hot air fan according to the embodiment of the present invention will be described with reference to FIGS. 2 to 6.

The atomized oil and primary air in the burner 13 are mixed to form a mixed gas, and the mixed gas g injected from the discharge part 131 at the initial startup of the hot air blower 100 is ignited by the ignition means 132. To become the primary combustion gas G1 inside the glowing tube 15.

After the stable ignition is confirmed, the secondary air A2 is introduced by opening the auxiliary duct 16 so that the secondary air A2 wraps around the discharge part 131 and the discharge part 131 is primary combustion. To prevent overheating from the gas (G1), while the mixed gas (g) and the secondary air (A2) is mixed, the combustion point of the primary combustion gas (G1) is moved to the middle portion of the red tube (15).

During this process, the glowing tube 15 in contact with the primary combustion gas G1 is heated to a high temperature, thereby heating the mixed gas g introduced from the discharge part 131 to a high temperature so that combustion occurs more easily. That is, while increasing the temperature of the mixed gas (g) flowing into the combustion chamber 11 in the discharge portion 131 to advance the combustion time, while increasing the combustion temperature inside the red tube 15 to complete combustion will be.

In addition, when the glowing tube 15 is heated, the combustion point of the primary combustion gas G1 moves near the discharge portion 131 in the middle of the glowing tube 15, and the overheating of the discharge portion 131 is performed by the secondary air. (A2) acts as a refrigerant and is prevented.

On the other hand, the secondary air (A2) bypassed through the air flow path 154 quickly exits to the flame discharge port 153 by forming a vortex to prevent overheating of the red heat pipe 15 and at the same time, the flame discharge port 153 It is mixed with the primary combustion gas (G1) exiting the) to further supply additional oxygen to help the combustion of the secondary combustion gas (G2).

At this time, in addition to the length of the red heat pipe 15, the total length of the flame (F) in which combustion occurs in the mixed gas (g) by the inlet of the secondary air (A2) is further longer, the complete combustion of the oil can be made.

In addition, when the cross section of the glowing tube 15 is gradually formed, since the discharge speed of the primary combustion gas G1 is further increased, the length of the flame formed by the secondary combustion gas G2 becomes longer. When the jaw 155 is formed at the end of the pipe 15, there is a slight decrease in the discharge rate, but as the mixing of the primary combustion gas G1 and the secondary air A2 is made smoothly, more complete combustion is achieved. .

In addition, the soot generated in the primary combustion gas (G1) can escape to the flame discharge port 153 without sticking to the inside of the red heat pipe 15, thereby increasing the decomposition holding period of the combustion chamber 11 for convenient management. It will be lost.

Subsequently, after the combustion is completed, the gas is discharged into the communication 123 inside the heating chamber 12 connected to the combustion chamber 11, and the fan 121 is provided on the side of the communication 123 heated by the burned gas. Outside cold air is heated while passing through the communication 123 to heat the above-described indoor space.

1 is a block diagram of a hot air fan according to an embodiment of the present invention.

Figure 2 is a side cross-sectional view showing the main portion of the main body employed in the hot air fan shown in FIG.

3 is an enlarged side cross-sectional view of B of FIG. 2;

4 is a front sectional view taken along line AA ′ of FIG. 2.

Figure 5 is a side cross-sectional view showing the main portion of the combustion chamber and the burner employed in the hot air according to another embodiment of the present invention.

6 is a state diagram showing the use of the combustion chamber and the burner shown in FIG.

Explanation of symbols on the main parts of the drawings

100: hot air fan 1: body 11: combustion chamber

12: heat generating chamber 121: fan 122: hot air discharge outlet

123: communication 13: burner 131: discharge part

132 ignition device 14 duct 15 heat tube

151: fixing means 152: inner diameter 153: flame discharge outlet

154: air flow path 155: jaw 156: inner end

16: auxiliary duct 161: flow rate control means, damper 2: storage tank

3: purifier 4: atomizer 5: air supplier

g: Mixed gas A2: Secondary air G1: Primary combustion gas

G2: Secondary combustion gas F: Flame

Claims (8)

The main body 1 includes a combustion chamber 11 and a heat generating chamber 12 formed at an upper portion thereof, and a fan 121 is provided at one side of the heat generating chamber 12 and a hot air outlet 122 is provided at the opposite side. )Wow, A communication 123 provided in communication with the combustion chamber 11 in the heat generating chamber 12 and withdrawn to the outside; A burner 13 fixed to the side wall of the combustion chamber 11 and having a discharge portion 131 protruding into the combustion chamber 11 to discharge the mixed gas mixed with oil and primary air; Ignition means 132 provided around the discharge portion 131, A duct pipe 14 protruding from the discharge part 131, A red light tube 15 provided through the fixing means 151 in the duct pipe 14 so that the flame generated from the discharge portion 131 is in contact with and glowing; In the lower portion of the discharge portion 131 side of the duct 14 is provided to communicate with the outside through the lower plate 111 of the combustion chamber 11, the opening and closing degree is adjusted through the inflow amount adjusting means 161 Hot air fan comprising a secondary duct (16). The method of claim 1, The glowing tube 15 has an inner diameter 152 larger than the outer diameter 131a of the discharge portion 131, and the inner end 156 of the glowing tube 15 moves to the outside of the discharge portion 131. Spaced apart, Between the circumference of the discharge portion 131 and the inner end 156 of the glowing tube 15, the secondary air inflow space (S) for introducing secondary air required for combustion to the front center of the discharge portion (131) Hot air fan characterized in that is formed. The method of claim 1 or 2, wherein the auxiliary duct 16, Hot air blower characterized in that the secondary air is provided to be laterally circumferentially around the duct pipe (14) to be introduced while causing the vortex. The method of claim 1 or 2, wherein the fixing means 151, And a rib forming an air passage (154) around the glowing tube (15) by interconnecting the inner side of the duct tube (14) and the outer side of the glowing tube (15). According to claim 1, The inflow rate adjusting means 161, Hot air blower, characterized in that made of a damper for adjusting the flow rate of the secondary air by adjusting the angle of the opening and closing plate (161b) by the drive of the motor (161a). In claim 1, The oil fan is characterized in that the vegetable oil or animal oil. In claim 1, The cross-sectional area of the heat pipe (15), characterized in that the hot air fan is gradually narrowed away from the discharge portion (131), so that the discharge speed of the combustion gas increases. 8. The method of claim 7, End of the heat pipe 15 is a hot air fan, characterized in that the jaw (155) is further formed to protrude inward to form a vortex.

Images