JP2011214767A - Turning combustion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a turning combustion device capable of effectively using biomass fuel such as chaff and rice straw while maintaining a favorable combustion state.SOLUTION: The turning combustion device comprises: a combustion cylinder 1 forming a combustion chamber 2 extended vertically and having a closed upper end; an upward turning air current generation mechanism 4 provided at the lower side of the combustion cylinder 1; and a flame radiation mechanism 5 radiating combustion flame downwardly from the upper end to the inside of the combustion chamber 2. The turning combustion device forms: an upward turning air current layer (a) where combustion air supplied to the inside of the combustion chamber 2 via the upward turning air current generation mechanism 4 is made to turn and ascend along the inner peripheral face of the combustion chamber 2; and a downward turning air current layer b which is surrounded by the upward turning air current layer (a) since the upward turning air current layer (a) is inverted on the upper end 3 face within the combustion chamber 2 and is made to turn and descend. While the chaff supplied to the lower part of the combustion chamber 2 is made to turn by the upward turning air current layer (a) and the downward turning air current layer b, the chaff is ignited by the combustion flame d of the flame radiation mechanism 5 and continuously burned.

Description

  The present invention relates to a swirl combustion apparatus that burns strip-shaped biomass fuel such as rice husk, shredded rice straw or large sawdust on a swirling airflow.

  Japanese Patent Application Laid-Open No. 2005-300022 discloses a combustion apparatus that burns solid fuel such as woody biomass and intends complete combustion by generating a swirling flow of combustion air in a furnace tube. Further, a biomass combustion apparatus that supplies biomass fuel and combustion air into a furnace and performs co-firing with an auxiliary burner is described in Japanese Patent Application Laid-Open No. 2007-212119 and Utility Model Registration No. 3142548, respectively. In addition, the eruption part of the gun type burner is surrounded by a combustion cylinder, and a spiral airflow is generated in the combustion cylinder to efficiently burn even if the fuel used is vegetable waste oil such as petroleum waste oil or edible oil. The concept to be introduced is introduced in Japanese Patent Application Laid-Open No. 2009-74784.

JP 2005-300022 A JP 2007-212119 A Utility Model Registration No. 3142548 JP 2009-74784 A

  Rice husks and rice straw are produced in large quantities as by-products of rice farming, but these are extremely important to promote effective use as biomass fuel together with large sawdust that is produced in large quantities during sawing in order to promote a low-carbon environment and control global warming. It is. However, rice husks, rice straw, and the like generate a large amount of smoke during the period from ignition to a stable combustion state and during fire extinguishing. In addition, it cannot be said to be a fuel that is very convenient because it requires a considerable amount of heat and time to ignite at the start of combustion, and this has led to the widespread use of heating devices and water heaters that use biomass fuel as a heat source. The situation is not progressing.

  On the other hand, in the preparation process in rice farming, the drying of rice straw and the rice husk are generally performed in parallel, so that the rice husks generated in the rice hulling process are directly used as fuel for drying the rice bran. If it can be used, it is very useful for the self-contained effective use of by-products generated in the preparation process, together with the effect of saving fossil fuels such as kerosene and gas.

  However, in order to promote the spread of biomass combustion equipment such as rice husks and rice straw, currently used combustion equipment such as kerosene and gas is automatically controlled. It is important to have the convenience that even if it is used, it can be operated automatically and does not require troublesome operations.

  Accordingly, the present invention provides an upward swirling airflow layer in which combustion air supplied into a combustion chamber extending in the vertical direction swirls and rises along the inner peripheral surface of the combustion chamber, and this upward swirling airflow layer is formed at the upper end surface of the combustion chamber. A descending swirl airflow layer is formed that is reversed and surrounded by the ascending swirl airflow layer, and the biomass fuel supplied to the lower part of the combustion chamber is ignited and burned while being swirled by the ascending swirl airflow layer and the descending swirl airflow layer Is to provide a swirl combustion device that can easily and effectively use biomass fuels such as rice husks and rice straw while maintaining a good combustion state regardless of increase or decrease in the amount of fuel supplied. It is the purpose.

  The swirl combustion apparatus of the present invention that achieves the above object is a swirl combustion apparatus that burns strip-shaped biomass fuel such as rice husk, shredded rice straw or large sawdust on a swirling airflow, and extends in the vertical direction. Combustion cylinder formed with a combustion chamber closed at the upper end, an ascending swirl airflow generation mechanism provided at the lower portion of the combustion cylinder, and a flame emission mechanism that radiates a combustion flame downward from the upper end into the combustion chamber, The combustion air supplied to the combustion chamber via the updraft generation mechanism swirls and rises along the inner peripheral surface of the combustion chamber, and the upturning swirl layer is inverted at the upper end surface of the combustion chamber. Forming a downward swirling airflow layer surrounded by the ascending swirl airflow layer, and lowering the biomass fuel supplied to the lower part of the combustion chamber by the upturning swirl airflow layer and the descending swirl airflow layer. It is characterized in that to sustain ignition to burn with a combustion flame.

  In the present invention, the ascending air flow generation mechanism provided at the lower portion of the combustion cylinder is composed of a high-pressure air injection nozzle that supplies combustion air and an annular guide wing body that surrounds the periphery and generates an outflow air current as an upward swirling airflow. The biofuel supply port is provided so as to be introduced toward the upward swirling airflow layer in the vicinity of the upper portion of the annular guide blade body, and the lower end of the combustion cylinder is exhausted from the combustion chamber. It is preferable that the road is formed. In addition, it is preferable that the supply path of the biomass fuel supplied to the lower part of the combustion chamber is provided with a pulverization mechanism for grinding the biomass fuel by the supply pressure.

  According to the swirl combustion device of the present invention, the combustion air supplied into the combustion chamber extending in the vertical direction swirls and rises along the inner peripheral surface of the combustion chamber, and the ascending swirl airflow layer burns. A downward swirling airflow layer is formed that is reversed at the upper end surface of the chamber and surrounded by the rising swirl airflow layer and descends, and the biomass fuel supplied to the lower part of the combustion chamber is swirled by the ascending swirl airflow layer and the downturning swirl airflow layer By igniting while maintaining combustion, it is possible to easily and effectively use biomass fuels such as rice husks and rice straw while maintaining a good combustion state regardless of increase or decrease in the amount of fuel supplied. In the swirl combustion apparatus of the present invention, the combustion cylinder can be reduced in size by multilayering the swirl airflow in the combustion cylinder, and combustion is achieved by forming a swirl airflow layer along the inner peripheral surface of the combustion cylinder. By suppressing the temperature rise of the tube, it can be effectively used as a safe continuous use heat source for a paddy drying device or an agricultural facility.

It is sectional drawing of the swirl combustion apparatus which concerns on one embodiment of this invention. It is sectional drawing which shows a combustion aspect same as the above. It is a perspective view same as the above. It is sectional drawing of an updraft production | generation part. It is a perspective view same as the above. It is a perspective view which shows a fuel supply part partially broken. It is sectional drawing same as the above.

  In the drawings, a swirl combustion apparatus according to the present invention is illustrated which burns rice husks. Reference numeral 1 denotes a combustion cylinder which forms a cylindrical combustion chamber 2 extending in the vertical direction, and an upper end 3 of the combustion chamber 2 forms a closed surface. An upward swirling airflow generating mechanism 4 is provided at the lower portion of the combustion cylinder 2, and a flame that radiates a combustion flame downward from the upper end of the combustion chamber 2 to the upper end 3 that forms a closed surface of the combustion chamber 2. A radiation mechanism 5 is provided. It is desirable to install the combustion cylinder 1 substantially along the vertical direction, that is, the direction of gravity.

  The ascending air flow generation mechanism 4 provided at the lower part of the combustion cylinder 1 is composed of a high-pressure air jet nozzle 6 for supplying combustion air and an annular guide blade body 7 surrounding the periphery thereof to generate the jet air flow as an ascending swirl air flow. The fuel husk supply port 8 is provided in a tangential direction with respect to the cylindrical combustion chamber 2 so as to be introduced toward the flow direction of the rising swirl airflow layer at a position near the upper side of the annular guide blade body 7. . The lower end of the combustion cylinder 1 forms an exhaust passage 9 for discharging combustion exhaust from the combustion chamber 2, and an exhaust duct is connected to the exhaust passage 9, and exhaust gas that is hot air is used as a heat source. In such a case, an appropriate duct is connected (both not shown). The heat source can be used for drying other firewood and heating for agricultural production facilities.

  The annular guide wing body 7 constituting the updraft generating mechanism 4 is provided with a curved swirling airflow generating blade 11 on the inner peripheral surface of the cylindrical portion 10, and swirling airflow jets between adjacent swirling airflow generating blades 11. An outlet 12 is provided. The high-pressure air jet nozzle 6 for supplying combustion air has a nozzle port 13 at the center of the annular guide blade body 7, and the high-pressure air jetted from the nozzle port 13 blows against the curved swirl airflow generating blade 11. A descending swirl airflow layer that is generated in an ascending swirl airflow layer a along the inner peripheral surface of the combustion chamber 2 and rises in the combustion chamber 2, hits the upper end 3, reverses and is surrounded by the ascending swirl airflow layer a and descends. b reaches the position of the annular guide vane body 7, and again joins the ascending swirl airflow layer a to repeat the action of the descending swirl airflow layer b reversed from the upper end in the combustion chamber 2. The air flows through the exhaust passage 9 through the exhaust passage 9.

  For this reason, the rice husk c supplied from the fuel husk supply port 8 to the lower part of the combustion chamber 2 rises while turning in the combustion chamber 2 along the upward swirling airflow layer a, and the upper end of the combustion chamber 2 After reaching the above, it descends while swirling on the descending swirl airflow layer b, but further acts to repeat the ascending swirl and the descending swirl. Since the pressure in the lower part of the combustion chamber 2 is increased by the generation of the rising swirl airflow layer a as described above, a phenomenon in which air flows backward from the rice husk supply port 8 opened at that position causes a flame to blow out. There is a risk of hindering the supply of rice husk c. Therefore, in the illustrated embodiment, the rice husk supply port 8 is provided with a high-pressure air blowing pipe 8a for blowing the rice husk c so as to supply the rice husk c with the blowing of the high-pressure air e.

  The combustion cylinder 1 has a burner 14 attached to the upper end 3 of the combustion cylinder 1, and the flame emission mechanism 5 for radiating the combustion flame d downward from the upper end into the combustion chamber 2. Is located at the upper end in the combustion chamber 2 and is ignited in the chaff c rotating as described above by the combustion flame d ejected downward from the flame port 15 in the combustion chamber 2. After the combustion chamber 2 reaches a high temperature at which combustion is continued, the ascending and descending swirls are repeated to burn the rice husk c and the combustion flame is generated up to the position of the annular guide blade body 7. Even if the combustion of the burner 14 is stopped, the combustion state of only the chaff c is maintained. Accordingly, the operation time of the flame radiation mechanism 5 is short, and a liquid or gaseous fluid fuel that is easy to control is used as the fuel.

  In order to burn the rice husk c well in the combustion chamber 2 while being swirled, it is preferable that the rice husk c is appropriately pulverized and has a uniform shape. Therefore, the fuel supply passage 16 following the rice husk supply port 8 is provided with a crushing mechanism 17 for grinding the rice husk c by supply pressure. The crushing mechanism 17 for crushing the rice husk c is composed of a squeeze conveyor 18 for moving the husk c in one direction and a grinder 19 facing the moving end with an interval. The grinding machine 19 is made of a hard material having a large number of small protrusions 20 on the surface facing the screw conveyor 18. 21 is a rice husk hopper.

DESCRIPTION OF SYMBOLS 1 Combustion cylinder 2 Combustion chamber 3 Upper end of combustion chamber 4 Ascending swirl airflow generation mechanism 5 Flame emission mechanism 6 High-pressure air ejection nozzle 7 Annular guide wing body 8 Rice husk supply port 8a High-pressure air blowing pipe 9 Exhaust passage 10 Cylindrical portion 11 Swirling airflow generation Blade 12 Swirl air jet 13 Nozzle port 14 Burner 15 Flame port 16 Supply path 17 Crushing mechanism 18 Squee conveyor 19 Grinding machine 20 Small protrusion 21 Rice husk hopper a Ascending swirl air flow layer b Down swirl air flow layer c Rice husk d Combustion flame e High-pressure air

Claims (4)

A swirl combustion device for burning a strip-shaped biomass fuel such as rice husk, shredded rice straw or large sawdust on a swirling airflow,
A combustion cylinder which forms a combustion chamber extending vertically and whose upper end is closed;
An ascending swirl airflow generating mechanism provided at a lower portion of the combustion cylinder;
A flame radiating mechanism for radiating a combustion flame downward from the upper end of the combustion chamber;
The combustion air supplied to the combustion chamber through the updraft generation mechanism swirls and rises along the inner peripheral surface of the combustion chamber, and the upturning airflow is inverted at the upper end surface of the combustion chamber. Forming a descending swirl air flow layer surrounded by the up swirl air flow layer and swirling down,
A swirl combustion apparatus characterized in that a biomass fuel supplied to a lower part of the combustion chamber is swung by an ascending swirl airflow layer and a descending swirl airflow layer while being ignited by a combustion flame of the flame radiation mechanism and sustaining combustion.   The ascending air flow generation mechanism provided at the lower part of the combustion cylinder is composed of a high-pressure air injection nozzle that supplies combustion air and an annular guide wing body that surrounds the periphery of the nozzle and generates an upward swirling air current. The swirl combustion apparatus according to claim 1, wherein the mouth is provided so as to be introduced toward a flow direction of the ascending swirl airflow layer at a position near the upper portion of the annular guide blade body.   The swirl combustion apparatus according to claim 1 or 2, wherein the lower end of the combustion cylinder forms an exhaust passage for discharging combustion exhaust from the combustion chamber.   The swirl combustion apparatus according to claim 1, 2, or 3, wherein a supply path for biomass fuel supplied to a lower part of the combustion chamber is provided with a pulverizing mechanism for grinding the biomass fuel by supply pressure.

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