WO2016014004A1

WO2016014004A1 - A continuous granular fuel burner

Info

Publication number: WO2016014004A1
Application number: PCT/TR2015/050042
Authority: WO
Inventors: Muhsin KAHYAOĞLU
Original assignee: Kahyaoğlu Maki̇na Tarim Madenci̇li̇k İnşaat Mühendi̇sli̇k Taahhüt Sanayi̇ Ve Ti̇caret Li̇mi̇ted Şi̇rketi̇
Priority date: 2014-07-23
Filing date: 2015-07-22
Publication date: 2016-01-28

Abstract

The invention is a burning system (8) which provides a continuous burning of all granular fossil fuels or biofuels with high efficiency and automatically without damaging the environment and without the need of an operator intervention to open the combustion chamber cover during the time of operation and which provides discharging of the ash and slag, the combustion residues, to the outside of the combustion housing again automatically and continuously. It comprises a rotary grate (1) which is made of suitable grate material, comprises protrusions suitable for carrying the fuel thereon, and rotates around its own axis at an intended angle degree and intended direction with the power that it receives from a drive element or the human power. The burning system (8) provides the different fuels to be burnt in one furnace housing (11) simultaneously. Thereby, it increases the energy efficiency and protects the environment.

Description

A Continuous Granular Fuel Burner

TECHNICAL FIELD

The invention relates to the burners which will provide continuous burning of all granular fossil fuels or biofuels.

The invention especially relates to the burners which will provide continuous burning of all granular fossil fuels or biofuels without the need of an operator intervention to open the combustion chamber cover during the time of operation.

PRIOR ART Today, the energy gap is continuously increasing due to the rising competition, growing environmental awareness, the demand of comfort by many more people in addition to the production need increasing in accordance with the increasing population. Said energy demand causes political and economic crisis between the countries. Continuous burning of the fuels obtained from any type of organic waste to be utilized as fuel in addition to the granular fossil fuels in the same machine more ecologically and efficiently without experiencing a mechanical problem will provide a significant advantage in this field.

A diverse range of burners are used for burning the fuels in the prior art. The object of the burners is to obtain maximum energy from the fossil fuels or similar fuels, thus to provide an efficient burning. One of these burners used for the preceding object is the burner type called stoker burners.

The stoker burners are the systems generally fed with the Archimedean screw. Said burners are usually formed of suitable material having a trapezoid structure in the form of one-piece or sectional grates by being arranged in order. Such type of burners has been known since 1920s and is still being commonly used. Besides, circular stoker burners are available as well. Such type of burners are manufactured and used in a manner to be fed from the bottom in low capacities and from the top in high capacities. In such type of burners, the fuel again being in a stock tank is supplied to the fixed, circular and hollow combustion housing from the bottom with an Archimedean screw in low capacities. Likewise, combustion air is supplied to the holes in said combustion pit with pressure from the bottom. In higher capacities, on the other hand, the fuel is supplied to a rotary combustion pit from the edge and top of the combustion pit. The combustion air enters into the combustion chamber through the gaps of the grate in the combustion pit due to the low pressure generated by combustion gases drawn by means of a draught inducer. Slag crusher apparatus is incorporated into some of these models. Ash and slag, the combustion residues, are discharged through the hole in the middle of the rotary grate.

Apart from the aforementioned types, stoker burner types such as sliding grate burners, chain- driven burners, discharge burners and fluidized-bed burners are also available. Said burners comprise some advantages and drawbacks over one another. The types of such burners are chosen in accordance with the need.

Variable demands of energy cannot be supplied from the same burners efficiently in the existing systems. If a burner having a trapezoidal combustion pit with screw is designed for a 300 kg/hour capacity, a fuel supply with +- 10% fluctuation is allowed in said burner. Otherwise, some parts of the grate are left empty and significant changes occur in the amount of the combustion air. This situation reduces the temperature of the combustion chamber and damages the combustion regime and causes significant loss of efficiency.

In fact, in all the furnaces manufactured with the existing technology, it is a great ability to burn the fuels with different energy levels at the same grate base even if with small fluctuations. Especially, burning of the lignite having variable chemical properties in the grate assembly of the existing burners is quite difficult. In burners with a fixed grate, as the grates through which the combustion air exits are frequently closed, air entry occurs insufficiently. The combustion regime is damaged due to the accumulation of ash and slag on the grate. Due to said problems in such type of furnaces, for such burners combustion efficiency at a rate of 60-65% is mentioned commonly in the literature.

In burners with a moving grate, on the other hand, as lignites with low ash fusion point are used, the fused ash is stuck on the moving surfaces of the grate, thus causing the grates to be stuck and the burner to be damaged and nonfunctional. Today, burning of the lignite with high calorific value but low ash fusion point and the lignite with low calorific value but high ash fusion point in the existing fixed or moving grate surfaces at the same furnace requires a substantial capability. This is because the rapid formation of slag in the fuel with low ash fusion temperature interrupts the flow of the fuel and exit of the combustion air, thus damaging the combustion regime. However, the same furnace can burn the low-calorie fuel with high ash fusion point efficiently.

Some applications are encountered during the patent search regarding the burning systems. One of them is the patent application No. TR2001/02889. In the application No. TR2001/02889 a furnace which can burn any type of granular fuel with a thickness of 0-18 mm and has an ash discharge system is disclosed. Said invention provides economic heat production with fuels which can be easily and cheaply supplied in any small- and medium-scale industrial plants, greenhouses and animal houses requiring heat. Another application regarding the burning systems is the application No. TR2011/10356. In said application a boiler which provides burning of fine coal and bio-granules together and separately is disclosed. It is disclosed that the invention can be used in the public and industrial energy systems which require burning of the fine coal and bio-granules without the formation of slag in the boiler room systems. However, the system developed for burning without the formation of slag in said invention does not provide completely effective burning of the fuel. Furthermore, incorporating a rotary grate into the system additionally is not possible. Therefore, a change cannot be made in the system and the fuel cannot be burnt in a desired manner in areas where burning much more fuel effectively is desired. To conclude, improvements are being made regarding the burning systems, therefore; new embodiments which will eliminate the aforementioned disadvantages and offer solution to the existing systems are needed.

OBJECTS OF THE INVENTION

The present invention relates to the burning systems which meet the aforementioned requirements, eliminate all the disadvantages and offer some additional advantages.

The object of the invention is to produce grate parts which are made of suitable grate material, comprise protrusions suitable for carrying the fuel thereon, are formed of one or multiple part/s according to the size thereof, comprise grooves suitable for discharging the combustion air at the flanks thereof, and form a ring with an intended diameter when mounted. Thereby, it is aimed to burn the fuel by moving the same on the grate parts efficiently.

One object of the invention is to form a hollow cylinder at a desired length by arranging side by side the grate parts whose one row forms a ring with a certain thickness. Thereby, it is aimed to convey the combustion air through the cylinder and the fuel from outside the cylinder.

Another object of the invention is to produce connection plates which are disposed on the hollow cylinder, wherein the grate parts can form a ring by being attached to the lugs thereon. Thereby, it is aimed to provide a desired number of grate parts to be mounted on the system.

Another object of the invention is to form a tube on which said plates having lugs are mounted. Thereby, it is aimed to form air inlet holes between the plates having lugs mounted on said tube where the combustion air is taken down to the grate. Thereby, it is aimed to provide an effective and efficient burning.

Another object of the invention is produce the air inlet hole formed between the plates having lugs in a structure suitable for allowing the sufficient amount of air to pass therethrough so as to burn the fuel carried by the grate section between the two plates having lugs. Thereby, it is aimed to provide an effective and efficient burning. Another object of the invention is to increase the number of the grates arranged circularly and to increase combustion surface of the grate, thus the fuel burning capacity of the burner. Thereby, it is aimed to burn the fuel at a desired level and efficiently. Thereby, it is aimed to provide modularity of the system. Another object of the invention is to present a cylindrical embodiment which will provide the combustion air to be transferred into the furnace in a leak-proof manner upon entering into the tube and comprise two openings divided preferably into two by an inner plate and suitable for the discharge of the combustion air through the end sections thereof. Thereby, it is aimed to provide an effective and efficient burning. Another object of the invention is to use a slag crusher which provides the crushing of the ash and slag remaining after the fuel is completely burnt on the rotary grate in order both to prevent said ash and slag from being stuck to the grate parts and to facilitate discharging of the same to the outside of the combustion housing by means of the ash discharge spiral. Thereby, it is aimed to crush the slags in a desired manner and to provide an effective burning. Another object of the invention is to provide discharging of the ash and slag remaining after the fuel is burnt to the outside of the combustion housing by means of the ash discharge spiral. Thereby, it is aimed to provide an effective burning by cleaning the ashes continuously.

Another object of the invention is to provide the production of the burning system with a single rotary grate according to the energy need or with two rotary grates which are placed symmetrically and rotate reversely to each other upon supplying the fuel to the fuel tank from the middle point. Thus, it is aimed to use a desired number of rotary grates in the burning system preferably. Thereby, it is aimed to provide burning at a desired level and efficiency.

Another object of the invention is to produce a burning system which provides a continuous burning of all granular fossil fuels or biofuels with high efficiency and automatically without damaging the environment and without the need of an operator intervention to open the combustion chamber cover during the time of operation and which provides discharging of the ash and slag, the combustion residues, to the outside of the combustion housing again automatically and continuously. Thereby, it is aimed to present an effective and efficient burning system.

Another object of the invention is to produce an automatic burning system and to minimize the cost and labor. Thereby, it is aimed to increase the quality.

Another object of the invention is to increase the quality by producing a fully automatic burning system. Thereby, it is aimed to increase the energy efficiency and to reduce the carbon emission.

To achieve the preceding objects, the invention is a burning system which provides a continuous burning of all granular fossil fuels or biofuels with high efficiency and automatically without damaging the environment and without the need of an operator intervention to open the combustion chamber cover during the time of operation; provides discharging of the ash and slag, the combustion residues, to the outside of the combustion housing again automatically and continuously; comprises a furnace housing which provides loading of the fuel on the rotary grate and an air guide which transfers the combustion air into the rotary grate at desired flow rates and forms multiple flow rates, wherein it comprises a rotary grate which is made of suitable grate material, comprises protrusions suitable for carrying the fuel thereon, is formed of one or multiple part/s according to the size thereof, comprises grooves suitable for discharging the combustion air at the flanks thereof, forms a ring with an intended diameter when mounted, rotates around its own axis at an intended angle degree and intended direction with the power that it receives from a drive element or the human power, is used in a desired number in the burning system and provides the adjustment of the combustion degree of the fuel and the burning of the fuel by moving the same thereon; an air inlet duct which provides the transfer of the combustion air into rotary grates and conveys the combustion air to the rotary grates in a desired amount and manner thanks to the air inlet holes thereon; a connection plate which is disposed on the air inlet duct and provides the rotary grates to be connected to the burning system; an air conveying duct which provides the combustion air coming from the air conveying tube to be taken down to the combustion section of the grate from at least two different points thanks to the two air outlet holes disposed at the ends thereof; and an air outlet duct which provides the combustion air transferred through the air inlet duct required for burning of the fuel in the burning system to be transferred to the rotary grate inside the furnace housing in a leak-proof manner.

A burning system, wherein it comprises a circular plate which provides the rotary grate parts to form a cylindrical structure closed from the two sides and provides said cylindrical grate to rotate.

A burning system, wherein it comprises a slag crusher which provides the crushing of the ash and slag remaining after the fuel is completely burnt on the rotary grate in order both to prevent said ash and slag from being stuck to the grate parts and to facilitate discharging of the same to the outside of the combustion housing by means of the ash discharge spiral.

BRIEF DESCRIPTION OF THE FIGURES

The present invention should be evaluated with the figures described below to ensure the best understanding of the embodiment and advantages together with the additional elements of the invention.

Figure-1 is the general view of the burner having a single rotary grate. Figure-2 is the detailed view of the burner having a single rotary grate. Figure-3 is the general view of the burner having double rotary grates. PART NUMBERS

1 . Rotary grate

2. Connection plate

3. Air inlet duct

4. Circular plate

5. Air conveying duct

6. Air outlet duct

7. Slag crusher

8. Burning system

9. Fuel spiral

10. Ash discharge spiral

1 1 . Furnace housing

12. Air guide

12.1 Double chambers

12.2 Inner plate

13. Fuel tank

DETAILED DESCRIPTION OF THE INVENTION

In this detailed description, preferred embodiments of the burning system (8), which provides efficient and automatic burning of multiple fuels having different energy levels simultaneously, are described only for a better understanding of the subject without any limiting effect.

General Structure of the System

The general view of the burner system (8) having a single rotary grate (1 ) is given in Figure 1 . The burning system (8) is a burner which provides multiple fuels therein to be burnt simultaneously, efficiently and automatically. The burning system (8) is a system which provides a continuous burning of all granular fossil fuels or biofuels with high efficiency and automatically without damaging the environment and without the need of an operator intervention to open the combustion chamber cover during the time of operation and which provides discharging of the ash and slag, the combustion residues, to the outside of the combustion housing again automatically and continuously.

Referring again to Figure 1 , the rotary grate (1 ) is seen. The rotary grate (1 ) can be defined as a structure on which the fuel is burnt by moving. The rotary grate (1 ) can be described as a grate part which is made of suitable grate material, comprises protrusions suitable for carrying the fuel thereon, is formed of one or multiple part/s according to the size thereof, comprises grooves suitable for discharging the combustion air at the flanks thereof, and forms a ring with an intended diameter when mounted. A structure in the form of a hollow cylinder is formed at a desired length by arranging side by side said rotary grates (1 ) whose one row forms a ring with a certain thickness.

The connection plates (2) are used in order to form the aforementioned cylindrical structure. The connection plates (2) are the structures which the grates formed of circular rotary grate (1 ) parts can be mounted. In a preferred embodiment of the system, the connection plate (2) is a metal plate end section of which has a T-shaped lug. It is also possible to form various types of connection plates (2). Said connection plates (2) are mounted on the air inlet duct (3). The air inlet duct (3) provides the transfer of the combustion air down to the rotary grates (1 ). In a preferred embodiment of the system, the air inlet duct (3) is cylindrical and made of metal. The air inlet holes are disposed between the connection plates (2) mounted on the air inlet duct (3) where the combustion air is throw down to the rotary grate (1 ). Said air inlet hole has a structure suitable for allowing the sufficient amount of air to pass therethrough so as to burn the fuel carried by the rotary grate (1 ) section between the two plates (2). Again the circular plate (4) seen in Figure 1 provides the rotary grate (1 ) parts to form a cylinder closed from the two sides and provides said cylindrical grate to rotate. Thanks to the circular plate (4), a desired number of rotary grate (1 ) parts are fixed on the air inlet duct (3) after being arranged by means of the connection plate (2). The circular structure formed of said rotary grates (1 ) stands horizontally. The number of these rotary grates (1 ) arranged circularly is increased, thereby the combustion surface of the grate and the fuel burning capacity of the burner are also increased. A desired number of rotary grates (1 ) can be mounted side by side. The burning system (8) can also be produced with two rotary grates (1 ) which are placed symmetrically and rotate reversely to each other upon supplying the fuel to the fuel tank from the middle point. Such an embodiment is seen in Figure 3. Again the furnace housing (1 1 ) seen in same figure made of a suitable material is a housing which provides loading on the rotary grate (1 ) and in which the conveyor spirals providing the discharge of the ashes to the outside of the furnace are mounted. Said housing, in a preferred embodiment of the system, is formed of an opening through which the rotary grate (1 ) and the slag crusher (7) can enter; two metal walls formed of two successive parts at the front and two side walls interconnecting these walls, which are parallel to each other.

The detailed view of the burner having a single rotary grate (1 ) is given in Figure 2. The air conveying duct (5) seen in said figure is a structure which provides the discharge of the combustion air from the two different points and comprises an air guide (12) at the end thereof. The air guide (12) inner volume has a structure with double chambers (12.1 ) divided into two by at least one inner plate (12.2) In a preferred embodiment of the system, the air conveying duct (5) is cylindrical and made of metal. The air guide (12) disposed at the end of the air conveying duct (5) provides the combustion air to be transferred down to the rotary grate (1 ) in different flow rates. In the preferred embodiment of the system, the air conveying duct (5) is in the form of a valve operating automatically and transfers air down to the rotary grate (1 ) in two different flow rates. By means of the air conveying duct (5), the combustion air is transferred with higher pressure to the section of the rotary grate (1 ) where loading of the coal is performed and combustion is just started and with lower pressure to the section in the ash discharge direction where the combustion is partially completed.

On the other hand, the air outlet duct (6) again seen in Figure 2 provides the combustion air to be transferred into the furnace housing (1 1 ) in a leak-proof manner. In a preferred embodiment of the system, it has a cylindrical structure comprising two openings divided into two by an inner plate and suitable for the discharge of the combustion air through the end section thereof. Said air outlet opening formed of two sections at the end of the air outlet duct (6) divides the combustion air into two and transfers the same down to the rotary grate (1 ) through the holes between the connection plate (2) mounted on the air inlet duct (3). Referring again to Figure 2, the slag crusher (7) is seen. The slag crusher (7) provides the crushing of the ash and slag remaining after the fuel is completely burnt on the rotary grate (1 ) in order both to prevent said ash and slag from being stuck to the grate parts and to facilitate discharging of the same to the outside of the furnace housing (1 1 ) by means of the ash discharge spiral (10).The slag crusher (7) rotates in a reverse manner to the rotation direction of the rotary grate (1 ) and provides the combustion residues to be cut into small pieces and to be carried and discharged to the outside of the furnace by the ash discharge spiral (10). The slag crusher (7), in the preferred embodiment of the system, is a metal structure with one piece or multiple pieces which comprises hard protrusions thereon, is circular, and through the middle of which the spline shaft is fitted. If desired, slag crushers (7) can be designed in quite various shapes. Referring again to Figure 2, the fuel spiral (9) is seen. The fuel spiral (9) provides the fuel put into the fuel tank (13) to be conveyed into the burning system (8). Said fuel tank (13) is the area where the fuel to be burnt is loaded and/or stocked in the burning system (8). Likewise, the ash discharge spiral (10) provides the ash and slag, the combustion residues, to be discharged to the outside of the burning system (8). The general view of the burner system (8) having double rotary grates (1 ) is given in Figure 3. The structure seen in this figure is the same as the burning system (8) having a single rotary grate (1 ) attempted to be described in the previous lines apart from several differences. The double rotary grates (1 ) increase the combustion rate and degree of the fuel and provide the fuel to be burnt more effectively in the needed areas. As seen, the rotary grate (1 ) can be used so as to be two or more in number. Such use provides an option to the user of the burning system (8). Thereby, the end user can determine the combustion rate of the fuel by him/herself. Operation Mode of the System

The fuel is first transferred from the fuel tank (13) outside the burning system (8) into the furnace housing (1 1 ) by means of an Archimedean screw and then from the lower level of the horizontal middle point of the rotary grate (1 ) to between the grate surface and furnace housing (1 1 ). When the fuel is filled to the upper level of the rotary grate (1 ), it is ignited.

Subsequent to the ignition of the fuel, the rotary grate (1 ) starts to rotate slowly in a reverse manner to the fuel filling direction. Said rotation is controlled manually or electronically in connection with the fuel amount received. The combustion fan is activated simultaneously and transfers the combustion air to the section where the combustion operation of the grate takes place, by means of the rotary grate (1 ), connection plate (2) and air inlet duct (3).

Such controlled transfer of the combustion air is sufficient for cooling the grate and prevents the excess air amount from being increased unnecessarily. With the rotation of the rotary grate (1 ), the fuel continues to burn on the rotary grate (1 ) and is moved toward the ash discharge direction simultaneously. In a preferred embodiment of the system, burning of the fuel on the rotary grate (1 ) is completed at 120 degrees rotation distance of the rotary grate (1 ). The fuel which is burnt completely is poured through the rotary grate (1 ), crushed by the slag crusher (7) and discharged to the outside of the burning system (8) by means of the ash discharge spiral (10). Thereby, the combustion process ends.

As a result, a system which provides a continuous burning of all granular fossil fuels or biofuels with high efficiency and automatically without damaging the environment and without the need of an operator intervention to open the combustion chamber cover during the time of operation and which provides discharging of the ash and slag, the combustion residues, to the outside of the combustion housing again automatically and continuously is produced.

Attempted to be described above as the burning system (8) whichoperates in a fully automatic manner providesa cost-effective and problem-free burning process to the end user. . Thereby, labor and cost are reduced in the burning process and the quality is increased as a result of an efficient burning. The increased quality increases the energy efficiency as well. With the increase in energy efficiency, carbon emission is reduced, thereby; the environment is protected.

Claims

1 . A burning system (8) which provides a continuous burning of all granular fossil fuels or biofuels with high efficiency and automatically without damaging the environment and without the need of an operator intervention to open the combustion chamber cover during the time of operation; provides discharging of the ash and slag, the combustion residues, to the outside of the combustion housing again automatically and continuously; comprises a furnace housing (1 1 ) which provides loading of the fuel on the rotary grate (1 ) and comprises equipment providing the discharge of the ashes formed after burning to the outside of the furnace; an air guide (12) which transfers the combustion air into the rotary grate (1 ) at desired flow rates and forms multiple flow rates, characterized in comprising;

- a rotary grate (1 ) which rotates around its own axis at an intended angle degree and intended direction with the power that it receives from a drive element or the human power, is used in a desired number in said burning system (8) and provides the adjustment of the combustion degree of the fuel and the burning of the fuel by moving the same thereon;

- an air inlet duct (3) which provides the transfer of the combustion air into said rotary grates (1 ) and conveys the combustion air to the rotary grates (1 ) in a desired amount and manner thanks to the air inlet holes thereon;

- a connection plate (2) which is disposed on said air inlet duct (3) and provides said rotary grates (1 ) to be connected to said burning system (8);

an air conveying duct (5) which provides the combustion air exiting from the burning system (8) after the burning process to be discharged to the atmosphere from at least two different points thanks to the apparatus disposed thereon and guiding the air;

- and an air outlet duct (6) which provides the combustion air transferred through the air inlet duct (3) required for burning of the fuel in the burning system (8) to be transferred to said rotary grate (1 ) inside the furnace housing (1 1 ) in a leak-proof manner.

2. The burning system (8) as in Claim 1 , characterized in comprising a circular plate (4) which provides said rotary grate (1 ) parts to form a cylindrical structure closed from the two sides and provides said cylindrical grate to rotate.

3. The burning system (8) as in Claim 1 , characterized in comprising a slag crusher (7) which provides the crushing of the ash and slag remaining after the fuel is completely burnt on said rotary grate (1 ) in order both to prevent said ash and slag from being stuck to the grate parts and to facilitate discharging of the same to the outside of the furnace housing (1 1 ) by means of the ash discharge spiral (10).

4. The burning system (8) as in Claim 1 , characterized in comprising an air guide (12) the inner volume of which has a structure with double chambers (12.1 ) divided into two by at least one inner plate (12.2).