KR20100121270A - Pellet boiler - Google Patents

Abstract

PURPOSE: A pellet combustion system, which minimizes the sludge sticking to the bottom part of a pellet oxidizer, is provided to increase thermal efficiency by supplying new pellet after discharging ash. CONSTITUTION: A pellet combustion system comprises a pellet feeder(110), a pellet oxidizer(120) and an exhaust pipe(140). The pellet oxidizer has a plurality of ventilation holes. The pellet provided from the pellet feeder is naturally ignited through ventilation holes with the natural blast. An oblique side(124) of the pellet oxidizer inclines to at 30~45 degree in order to make combustion flame spread out.

Description

Pellet Combustion System {PELLET BOILER}

The present invention relates to a pellet combustion system, and more particularly, to a pellet combustion system that is environmentally friendly and that little sludge occurs for all grades of pellets.

Recently, due to the problem of energy crisis due to oil depletion and global warming due to the increase of carbon emissions, interest in environment-friendly energy is increasing under the banner of low carbon green growth.

In particular, pellet fuel has been in the spotlight as a natural-friendly fuel, and a pellet combustion system using this as a fuel is frequently used.

Pellet is a heating fuel extruded into a small cylindrical shape by crushing, drying, and compressing wood by-products generated in sawmills into small particles such as sawdust.

Most pellets are standardized in sizes from 6mm to 8mm in diameter, making them easy to transport and use. Unlike other fuels, their low flammability does not require any special equipment or equipment during transportation.

In addition, a small amount of toxic gases such as carbon monoxide or dust occurs during combustion.

On the other hand, in the past, as a raw material for pellets, sawdust and large fat rice of a sawmill were used, but in recent years, it has been extended to waste wood including bark, residues of the food industry, and rice straw of farms, and to improve the combustion efficiency of pellets. Low quality pellets with the same raw materials are also produced.

In general, pellets are divided into 4 grades according to the foreign substances and urea components. The lower quality pellets generate a large amount of sludge (sand, glass, etc.) due to incomplete combustion.

Such sludge sticks to the bottom of the pellet burner and prevents the ash from falling to the bottom, thereby increasing the incomplete combustion of the pellet and causing thermal efficiency to fall or malfunction.

In addition, it is not easy to clean the pellet burner due to the sludge, and there is a problem that the user is reluctant to use the pellet combustion system.

The present invention is to solve the above problems, an object of the present invention is to provide a pellet combustion system that can reduce the amount of sludge generated due to incomplete combustion of the pellets.

It is also an object of the present invention to provide a pellet combustion system having a good combustion efficiency.

In order to achieve this object, a pellet combustion system according to an embodiment of the present invention has a pellet feeder for supplying pellets, and a plurality of blow holes are formed so that the pellets supplied from the pellet feeder are ignited by natural blowing, and the combustion is unstable. A pellet burner inclined at least 30 to 45 degrees to spread, and an exhaust pipe communicating with the pellet burner and into which the air introduced into the blower hole moves.

As described above, according to the exemplary embodiment of the present invention, as the air blowing hole is formed in the pellet combustion portion for the combustion of the pellets naturally, the area of the pellets in contact with the air increases, whereby the pellets Can burn completely.

Accordingly, the amount of sludge generated by the combustion of the pellets and sticking firmly to the bottom of the pellet combustion portion can be reduced, so that ash can be smoothly escaped and new pellets can be supplied, thereby improving thermal efficiency.

In addition, malfunction of the pellet combustion system due to incomplete combustion of the pellets can be prevented and cleaning is easy.

In addition, a plurality of blow holes of 3.5 mm or more and less than 20 mm are formed at intervals of 30 mm or more and less than 50 mm, and have an inclination of 30 degrees to 45 degrees, so that they can interact with the exhaust pipe to provide optimum pellet combustion conditions. Can be.

In addition, further comprising a heat inducing unit for inducing heat generated while the pellet is burned to the edge of the pellet burner, it is possible to increase the thermal efficiency of the pellet combustion system.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 is a schematic cross-sectional view of a pellet combustion system according to an embodiment of the present invention, Figures 2 and 3 is a view showing a pellet burner, Figure 4a and 4b are sludge generated after the combustion of the pellet, respectively It is a comparative photograph showing the prior art example which shows a sludge, and this invention.

1, the pellet combustion system 100 according to an embodiment of the present invention is a pellet feeder 110, pellet combustion unit 120, combustion chamber 130, exhaust pipe 140, hot water coil 150 , Blower 160. It is configured to include an air circulation box 170, and the recirculation 180.

The pellet feeder 110 is for supplying pellets (P) to the pellet burner 120 in the combustion chamber 130, the fuel storage 112, fuel transfer unit 114, the rotating unit 116 And it may be configured to include a power generator 118.

The fuel storage unit 112 is located on one side of the combustion chamber 130, a space for temporarily storing the pellets (P) is provided therein, the stored pellets (P) to the fuel transfer unit 114 Holes are formed in the lower portion to be discharged.

The fuel transfer unit 114 provides a passage through which the pellets P discharged from the fuel storage unit 112 are transferred to the pellet combustion unit 120.

The rotating unit 116 rotates in the fuel transfer unit 114 so that the pellets P discharged from the fuel storage unit 112 can be transferred to the pellet combustion unit 120.

The power generating unit 118 provides a driving force for the rotation of the rotating unit 116, the amount of pellet (P) is transferred by the rotating unit 116 can be adjusted according to the drive speed of the power generating unit 118. have.

The pellet burner 120 is located inside the combustion chamber 130, and the pellets P supplied from the pellet feeder 110 are loaded.

The pellet combustion unit 120 is preferably made of a plate shape so as to increase the area of the pellet P in contact with the air in order to increase the combustion efficiency of the pellet (P).

In particular, the pellet burner 120 may include a bottom surface 122 and an inclined side surface 124.

The loaded pellets P may be fired manually or automatically by an igniter (not shown) such as a burner.

At least one grate 122a is formed on the bottom surface 122 of the pellet burner 120, and ash A generated by burning the pellet P through the grate 122a is reloaded 180. Falls on.

The interval between the grate 122a is preferably such that the pellet (P) can not easily fall to the bottom, most of the diameter of the pellet (P) 6mm to 8mm, as shown in Figure 2, grate ( The spacing between 122a) is preferably 4.8 mm or more and less than 5.8 mm, preferably 3.5 mm to 9 mm, smaller than the diameter size of the pellets P, so that ash can be easily escaped when supplying new pellets.

As shown in FIG. 3, at least one blowing hole 124a is formed in the inclined side surface 124 of the pellet burner 120, and air is naturally supplied to the pellet P through the blowing hole 124a. do.

For this reason, air may be widely contacted with respect to the entire pellet P located in the pellet combustion unit 120 so that combustion of the pellet P may proceed as a whole.

That is, the air naturally introduced into the air inlet 132 of the combustion chamber 130 naturally flows into the pellet combustion unit 120 through the blower hole 124a, thereby contacting the air of the pellets P. The area is increased to allow complete combustion of the pellets P, whereby sludge may hardly be generated.

At this time, whether or not the blowing hole 124a, the size and the interval between the blowing hole (124a) (the degree of distribution of the blowing hole 124a in the pellet burner 120), how much the sludge according to the quality grade of the pellet (P) In order to determine whether the high-quality pellets (A) to low-quality pellets (D) based on 20 kg of pellets (P) classified into 4 grades, the amount of sludge generated under various conditions during 24 hours of combustion was measured.

TABLE 1

Quality grade of pellet If there is no ventilation hole If there is a ventilation hole Diameter (mm)
Thickness (mm) 1.1 and above 3.5 3.5 or more but less than 4.5 ~ 18.8 or more but less than 20 20 or more but less than 21.2 A grade - 20-30 - - ~ - - 30 to 40 - - ~ - - 40-50 - - ~ - - 30-60 - - ~ -  - Class B 200 g 20-30 50 g 20g ~ 30 to 40 40 g 10g ~ 40-50 40 g 10g ~ 30-60 50 g 20g ~ C grade 400 g 20-30 100 g 40 g ~ 30 to 40 80 g 20g ~ 40-50  80 g 20g ~ 30-60 100 g 40 g ~ Class D 600 g 20-30 150 g 60 g ~ 30 to 40 120 g 20g ~ 40-50 120 g 20g ~ 30-60 100 g 60 g ~

As can be seen from Table 1, regardless of the quality grade of the pellet (P), the distance between the blowing holes 124a is 30mm or more and less than 50mm, the diameter of the blowing holes 124a is 3.5mm or more and less than 4mm, preferably In the case of 3.5 or more and 20 mm or less (in case of industrial pellet combustion system, the pellet combustion unit is large), it was found that the amount of sludge generated was smaller than that of the case without the blower hole 124a.

In addition, in order to determine the relationship between the shape of the pellet burner 120 and the pellet combustion efficiency, the inclination of the inclined side 124 according to the grade of the pellets (P) is changed by burning 20 kg of pellets (P) for 24 hours. The amount of sludge was measured.

At this time, the interval between the blow holes 124a was set to 35 mm, and the pellet burner 120 having the diameter size of the blow holes 124 a set to 4 mm was used.

TABLE 2

Quality grade
Angle A grade Class B C grade Class D 25 degrees or more but less than 30 degrees - 20g 30 g 40 g 30 degrees or more but less than 45 degrees - 5 g 10g 15 g 45 degrees or more but less than 50 degrees - 20g 30 g 40 g

As shown in Table 2, the sludge generated when the inclination of the inclined side surface 124 with the central axis of the pellet burner 120 is greater than or equal to 30 degrees and less than 45 degrees regardless of the quality grade of the pellet (P) It can be seen that the amount of is the smallest.

As a result of the two experiments, the most optimal combustion condition is that the pellet combustion unit 120 has a plurality of blow holes 124a at intervals of 30 mm or more and less than 50 mm, and the diameter of the blow holes 124a is 3.5 mm or more and 4.5 mm. It can be seen that the angle of the inclined side surface 124 with the central axis of the pellet burner 120 is less than 30 degrees and less than 45 degrees.

Referring to FIGS. 4A and 4B, which are representative of the experimental results, as shown in FIG. 4A, the pellet burner 120 having the above conditions as shown in FIG. 4B may be compared to the case where the blower hole 124a is not formed. It can be seen that little sludge is generated in the experiment.

That is, due to the pellet burner 120 having the conditions as described above, it is possible to completely burn the pellets P, and thus, the amount of sludge generated is small, so that the bottom surface 122 of the pellet burner 120 is reduced. The sludge doesn't stick to it.

This is because ash (A) is easily removed and removed to the ash tray 180 through the grate 122a, the circulation of the pellets (P) and the ash (A) supplied to the pellet burner 120 may occur smoothly. Make sure

In addition, the pellet combustion system 100 has the optimal thermal efficiency by the smooth circulation, it is possible to prevent the malfunction of the pellet combustion system 100 due to incomplete combustion of the pellets (P), easy to clean the pellet burner ( 120) there is no need to replace the economically efficient advantage.

At this time, the exhaust pipe 140 serves to assist the ventilation hole 124a of the pellet combustion unit 120 and natural ventilation to occur.

Here, in order to determine how much sludge is generated according to the length of the exhaust pipe 140, the length of the exhaust pipe 140 is changed according to the grade of the pellets P to measure the amount of sludge generated when burning the pellet P 20 kg. It was. In the experiment, the distance between the blow holes 124a is 35 mm, the diameter of the blow holes 124a is 4 mm, and the angle of the inclination of the inclined side surface 124 with the central axis of the pellet burner 120 is 30 degrees. 120) was used.

[Table 3]

Quality grade
Length (m) A grade Class B C grade Class D 2 or more but less than 3 - 15 g 25 g 35 g 3 or more but less than 4 - - 5 g 10g 4 or more but less than 5 - - 10g 15 g

As a result of the experiment, the length of the exhaust pipe 140 is an optimum condition for the pellet (P) to be burned, that is, in communication with the blowing hole 124a of the pellet burner 120 inside the combustion chamber 130 In order to optimize the air contact time of the pellets and naturally discharge the smoke generated in the it can be seen that it is preferable that less than 4m.

The combustion chamber 130 may be further formed with an air inlet 132 for introducing air to one side. Air is introduced from the outside through the air inlet 132, and the amount of air introduced from the outside may be controlled by an air inlet control unit (not shown).

The hot water coil 150 may be disposed on an outer circumference of the combustion chamber 130 and warmed by heat generated in the combustion chamber 130 to be used as a boiler.

Blower 160 is located on one side of the air circulation box 170 disposed outside the combustion chamber 130 to naturally indirect the outside air to promote the combustion of the pellets (P) loaded on the pellet burner 120 Can be supplied by

That is, the air generated by the blower 160 is compressed and stored in the air circulation box 170 and is indirectly supplied to the pellet burner 120 through the air inlet 132 to supply the pellets and air. While increasing the contact time of the air blower 160 by the sudden operation of a large amount of air is not instantaneously supplied to the pellet burner 120, a large amount of air can be supplied sequentially, the air of The amount can be smoothly adjusted using the blowing control means (not shown).

With respect to the above-described contents, in order to determine how much sludge is generated depending on the presence or absence of the air circulation box 170, the amount of sludge generated during combustion of the pellet (P) 20kg according to the grade of the pellet (P) was measured.

In the experiment, the distance between the blow holes 124a is 35 mm, the diameter size of the blow holes 124a is less than 4 mm, and the angle of the inclination of the inclined side 124 with the central axis of the pellet burner 120 is 30 degrees, the exhaust pipe length. 4m pellet burner 120 was used.

[Table 4]

Quality grade
Air circulation box A grade Class B C grade Class D If not - - - - If present - Thermal efficiency control Thermal efficiency control Thermal efficiency control

As can be seen from Table 4, irrespective of the quality grade of the pellet (P), when there is an air circulation box 170, not only the amount of sludge is generated but also the thermal efficiency can be adjusted to control the size of the flame, etc. .

Here, since it is possible to completely burn through the blow hole 124a of the pellet burner 120, the blower 160 and the air circulation box 170 is preferably optional.

The ash tray 180 is provided in the lower portion of the combustion chamber 130 so as to easily collect ash A falling through the grate 122a of the pellet burner 120.

5A is a view schematically showing a pellet combustion system according to another embodiment of the present invention.

Hereinafter, the same or similar reference numerals are used for components of another embodiment that are the same as or similar to the components of one embodiment, and duplicate descriptions are omitted and only other components will be described in detail.

Referring to FIG. 5A, the pellet combustion system 100 according to another embodiment of the present invention further includes a heat induction part 190 and a heat induction part fixing bar 198a.

The heat induction part 190 is provided above the pellet combustion part 120 in the combustion chamber 130, and guides heat generated while the pellet P is burned to the edge of the combustion chamber 130. Therefore, most of the heat can be transferred to the hot water coil 150 provided in the outer circumference or the outer circumference of the combustion chamber 130, the length of time that the heat stays in the combustion chamber 130 of the pellet combustion system 100 It is possible to increase the thermal efficiency.

In this case, the heat induction part 190 is a hemispherical plate with a hole formed in the center, and may be composed of first, second and third induction parts 192, 194, and 196 having diameter sizes of 70 mm, 100 mm, and 150 mm, respectively. In combination with the induction part fixing bar 198a, the combustion chamber 130 may be disposed at an inner center.

In addition, in another embodiment of the present invention, as shown in FIG. 5B, a fixing wire 198b is installed at the center of the combustion chamber 130 to fix the wire 198b. Can also be installed in the air by.

Of course, in addition to the heat induction unit 190 may be any shape as long as it can induce heat generated by the combustion of the pellet (P) to the edge of the combustion chamber 130.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 is a schematic cross-sectional view of a pellet combustion system according to an embodiment of the present invention.

2 and 3 is a view showing a pellet burner.

4A and 4B are photographs showing experimental results, respectively.

5A is a schematic cross-sectional view of a pellet combustion system according to another embodiment of the present invention.

5B is a schematic cross-sectional view of a pellet combustion system according to another embodiment of the present invention.

Claims (8)

A pellet feeder for supplying pellets, a plurality of blow holes are formed so that the pellets supplied from the pellet feeder are ignited by natural blowing, and a pellet burner having an inclined side surface inclined at least 30 to 45 ㅀ to spread combustion flames; And an exhaust pipe communicating with the pellet burner and configured to naturally blow air introduced into the blower hole. The method of claim 1, And a heat induction part configured to guide heat generated while the pellet is burned to the edge of the combustion chamber, above the pellet burner. The method of claim 2, The heat induction part pellet combustion system comprising a plurality of hemispherical plate and the fixing bar is formed with a central fixing hole. The method of claim 1, Pellet combustion system, characterized in that the grate is installed on the bottom surface of the pellet burner at intervals of 3.5 mm to 9 mm. The method of claim 4, wherein The diameter of the blowing hole is pellet combustion system, characterized in that less than 20mm 3.5mm. The method of claim 5, Pellet combustion system, characterized in that the spacing between the blowing holes is 30mm or more and less than 50mm. The method of claim 6, The length of the exhaust pipe is pellet combustion system, characterized in that less than 4m. The method of claim 6, And an air circulation box in which air from a blower is circulated outside the combustion chamber to be supplied to the combustion chamber.

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