JP4669973B2 - Waste cooking oil combustion method and combustion apparatus - Google Patents

Description

  The present invention relates to a combustion method and a combustion apparatus for waste cooking oil. More specifically, the present invention relates to a combustion method and a combustion apparatus for waste edible oil that can burn waste edible oil in the same manner as A heavy oil and the like.

  Conventionally, cooking oil has been used for cooking, cooking, etc. in households, restaurants, food manufacturers, etc., and waste cooking oil generated from households, etc. due to its use has reached 400,000 to 500,000 tons per year. It is also said. Almost half of this waste edible oil comes from food manufacturers, etc., of which major ones are collected by collectors, about 70% of which is used for feed, the rest being solvent, industrial It is reused as a raw material.

  On the other hand, most of the waste cooking oil from households, restaurants, small-scale food manufacturers, etc., accounting for the other half, is discharged into sewage without any treatment. Therefore, environmental pollution by this waste cooking oil has occurred.

  As a countermeasure, some local governments have tried to promote the recovery of waste edible oil and re-synthesize biodiesel oil from waste edible oil, for example, to effectively use the energy of waste edible oil. ing. However, since the equipment is large and equipment costs are high, it has not been spread on a nationwide scale. It is also conceivable to use biodiesel oil mixed with light oil, but doing so will result in a light oil transaction tax and will not be economically viable.

  However, if the waste edible oil can be burned with a pressure spray burner in a boiler or absorption refrigerator similar to fuel oil such as A heavy oil, recovery of the waste edible oil is promoted and environmental pollution caused thereby is also eliminated. Expected.

  However, when waste cooking oil is burned by the conventional pressure spray burner 100 as shown in FIG. 5, a large amount of unburned matter is deposited and adhered to the heat transfer surface such as the furnace wall, thereby inhibiting heat transfer. At the same time, there is a problem that such unburned material needs to be frequently removed and cleaned.

A technique for premixing and burning a liquid main fuel and a certain amount of waste edible oil is proposed in Patent Document 1.
JP-A-11-223326

  This invention is made in view of the subject of this prior art, Comprising: A waste edible oil combustion method and combustion apparatus which can burn waste edible oil with a pressure spray type burner like A heavy oil are provided. It is an object.

  As a result of earnestly researching such problems, the present inventors have heated the temperature of waste edible oil to 90 ° C. to 110 ° C., and prevent cooling of the waste edible oil by combustion air in the wind box, The same spray particle size and particle size distribution as those of A heavy oil were obtained, and it was found that good combustion could be achieved with a pressure spray burner, and the present invention was completed.

That is, the combustion method of cooking oil of the present invention, a cooking oil Ri by the pressure atomizing type burner comprising a combustion method for burning as with A heavy oil, waste cooking oil to be supplied to the burner 1.8MPa A procedure for increasing the pressure to ~ 2.5 MPa , a procedure for raising the waste edible oil supplied to the burner to 90 ° C to 110 ° C, and a procedure for increasing the amount of the waste edible oil by a predetermined amount and supplying it to the spray nozzle And cooling the waste cooking oil supplied to the spray nozzle by combustion air while returning the increased amount of waste cooking oil to the supply side, and maintaining the waste cooking oil supplied to the spray nozzle at the temperature And a procedure for performing.

Furthermore, in the combustion method of waste edible oil of the present invention, it is preferable that the ratio of the waste edible oil returned to the supply side is three times or more of the waste edible oil to be sprayed.

On the other hand, the waste edible oil combustion apparatus of the present invention is a combustion apparatus that burns waste edible oil in the same manner as A heavy oil by a pressure spray burner, and the burner supplies the waste edible oil to the spray nozzle. When a heat insulating outer tube that maintains a portion of the cooking oil the temperature of the cooking oil to be supplied to the spray nozzle with return to the supply side, to prevent cooling by combustion air to 90 ° C. to 110 ° C. It is characterized by comprising.

  In the combustion apparatus for waste edible oil of the present invention, it is preferable to include a heater for raising the temperature of the waste edible oil to a predetermined temperature.

  ADVANTAGE OF THE INVENTION According to this invention, the waste cooking oil can be burned completely and the outstanding effect that the clean surface without the adhesion and accumulation of incomplete combustion products on the heat exchange surface, such as a combustion chamber, is acquired. This also opens the way for the waste edible oil to be used as a fuel similar to the heavy fuel oil A, and the excellent effect that the recovery and reuse of the waste edible oil is promoted to prevent environmental pollution due to the waste edible oil is obtained. .

  Hereinafter, although the present invention is explained based on an embodiment, referring to an accompanying drawing, the present invention is not limited only to this embodiment.

  FIG. 1 is a cross-sectional view of a main part of a combustion apparatus having a return-type pressure spray burner applied to a combustion method according to an embodiment of the present invention, and the surroundings of the combustion apparatus of an absorption refrigerator equipped with the combustion apparatus. The fuel system and the like are shown in FIG.

  As shown in FIGS. 1 and 2, the return-type pressure spray burner B mainly includes a waste edible oil supply unit 10 that supplies waste edible oil and an air supply unit 20 that supplies combustion air for waste edible oil. It is prepared as a part.

  The waste edible oil supply unit 10 includes an inner pipe (supply pipe, for example, an inner diameter of 5 mmφ) 11 that supplies the waste edible oil, and an outer pipe (return pipe, for example, an inner diameter of 10 mmφ) that returns a part of the supplied waste edible oil to the supply side. 12, a double pipe 10A is provided with a supply / discharge block 13 at a base end portion thereof, and a spray block 14 is provided at a tip end portion thereof. The spray block 14 is the same as the spray nozzle in which the drip-proof valve 14a and the spray nozzle 14b are combined, which is used in a known return-type pressure spray burner, and therefore detailed description of the configuration is omitted.

  Here, the ratio of the waste edible oil returned to the supply side is 30% or more of the waste edible oil supplied from the viewpoint of maintaining the sprayed waste edible oil at a predetermined temperature while preventing cooling by the combustion air. Is done. That is, it is 3 times or more of the waste edible oil to be sprayed and the predetermined temperature is secured.

  The distal end of the inner tube 11 is projected from the outer tube 12 by a predetermined length and is fitted to the spray block 14. The fitted inner tube 11 is communicated with a flow path (not shown) formed in the spray block 14, and at a position protruding from the outer tube 12 of the inner tube 11, that is, at the distal end portion of the outer tube 12, Although not shown in the figure, a sealing member, for example, a lid is provided as appropriate, and the sealing of the portion is achieved. Although not shown, a required number of return holes for returning part of the waste edible oil to the outer tube 12 is provided at a position of the inner tube 11 located at the tip of the outer tube 12. Since the waste edible oil supply unit 10 is configured as described above, the temperature of the waste edible oil in the supply pipe 11 is maintained at a predetermined temperature. That is, the return oil flowing through the return pipe 12 prevents the edible oil inside the supply pipe 11 from being cooled by the combustion air, thereby keeping its temperature.

  As shown in FIGS. 1 and 3, the supply / discharge block 13 includes a return portion 15 that returns waste edible oil from the base end side of the double pipe 10 </ b> A and a supply portion 16 that supplies waste edible oil in this order. It is set as the rectangular parallelepiped block body joined.

  The return portion 15 is formed with a fitting portion 15b in which the outer tube 12 is fitted to a surface 15a facing the double tube 10A, and a return port 15c is formed on one side surface to be joined to the supply portion 16. An inner tube insertion passage 15e is formed through the surface 15d. The return port 15c communicates with the outer tube 12 fitted to the fitting portion 15b via a communication passage 15f formed inside the return portion 15. As shown in FIG. 3, the base end portion 12 a of the outer tube 12 fitted into the fitting portion 15 b is formed in a tapered shape. Thereby, fitting of base end part 12a is made easily.

  The supply portion 16 is formed with a fitting portion 16b into which the inner tube 11 is fitted on a joint surface 16a with the return portion 15, and an opening 16c is formed on one side surface. The surface on which the supply port 16c is formed is preferably a surface different from the surface on which the return port 15c is formed from the viewpoint of avoiding complicated construction of the supply pipe FP and the return pipe RP. The supply port 16c communicates with the inner tube 11 fitted to the fitting portion 16b via a communication passage 16d formed inside the supply portion 16. As shown in FIG. 3, the base end portion 11a of the inner tube 11 fitted to the fitting portion 16b and the inner tube insertion passage 15e is formed to be thin with a reduced outer diameter. Note that the base end portion 11a is not necessarily formed thin.

  Specifically, the air supply unit 20 is a wind box on which the double pipe 10A is mounted.

  Next, a fuel system and a combustion air system to the combustion apparatus A having the return type pressure spray burner B configured as described above will be described with reference to FIG. FIG. 2 is a system diagram around the combustion device of the absorption refrigerator equipped with the combustion device A.

  The fuel system F is composed of a waste edible oil system LF.

  The waste cooking oil system LF includes a waste cooking oil supply pipe FP that supplies waste cooking oil to the combustion apparatus A, and a waste cooking oil return pipe that returns a part of the waste cooking oil supplied to the combustion apparatus A to the supply pipe FP. RP.

  As shown in FIG. 2, the waste edible oil supply pipe FP has an inlet stop valve 41, a strainer 42, an air separator 43, a spray pump (pressurizing and feeding means) 44, and a heating unit from the upstream side where the waste edible oil is supplied. The vessel 45, the first electromagnetic valve 46, and the second electromagnetic valve 47 are interposed in this order, and the front end thereof is fitted to the supply port 16c of the supply / discharge block 13 of the combustion apparatus A. A portion from the outlet of the heater 45 of the supply pipe FP to the supply / discharge block 13 is covered with a tape-like heating member to heat and keep the portion. The supply / discharge block 13 is also kept warm in the same manner.

  The spray pump 44 is, for example, a gear pump, and has the ability to increase the pressure of waste edible oil to a pressure sufficient to give a spray energy that can obtain a spray particle size equivalent to A heavy oil, for example, 1.8 MPa to 2.5 MPa. It is said.

  The heater 45 is an electric heater from the viewpoint of controllability and miniaturization, and the temperature of the waste edible oil is such that the spray particle size equivalent to that of A heavy oil can be obtained, for example, 85 ° C to 110 ° C, preferably 90 ° C. It has the ability to raise the temperature to ˜110 ° C. However, the heater 45 is not limited to an electric heater, and may be a steam heater as long as controllability and size reduction equivalent to those of the electric heater can be achieved.

  Further, the return pipe RP from the supply / discharge block 13 of the combustion apparatus A is returned between the strainer 42 and the air separator 43. That is, the tip of the return pipe RP is joined to the supply pipe FP between the strainer 42 and the air separator 43. The reason why the return pipe RP is returned to this position is to separate bubbles generated in the return pipe RP due to a pressure change in the return pipe RP by the air separator 43 and to heat newly supplied waste cooking oil. It is.

  As shown in FIG. 2, the return pipe RP includes a flow control motor-operated valve 51, a solenoid valve (hereinafter referred to as a return oil solenoid valve) 52, and a check valve 53 from the upstream side (supply / discharge block 13 side). A temperature switch 54 is provided on the upstream side of the flow control motor operated valve 51. The check valve 53 and the return oil solenoid valve 52 prevent the backflow of waste edible oil through the return pipe RP while the absorption refrigerator or the like is stopped.

  Further, the return pipe RP is provided with a bypass pipe 55 that bypasses the flow control electric valve 51 and the return oil solenoid valve 52. As shown in FIG. 2, the bypass pipe 55 is provided with an orifice 56 and an oil electromagnetic valve 57 so that the waste edible oil that can keep the temperature of the waste edible oil supplied to the oil supply unit 10 at the time of activation returns. Has been.

  The combustion air system FA includes a blower 71 and a damper (air flow control valve) 72.

  The fuel ignition system IG includes a spark plug 81.

  Therefore, in the absorption refrigerator having the combustion apparatus A having the return type pressure spray burner B having such a configuration, as shown in FIG. 2, the combustion air from the blower 71 of the combustion air system FA is used. The air is flow-controlled by the damper 72 and supplied to the wind box, supplied to the combustion section as combustion air via the diffuser 21, and used for burning waste cooking oil.

  The waste edible oil sprayed from the waste edible oil supply unit 10 of the return type pressure spray burner B is mixed with the combustion air and then ignited by the ignition plug 81 of the fuel ignition system IG to start combustion. The

  Specifically, the edible oil is ignited as follows. That is, when the waste edible oil is heated and reaches a predetermined temperature, that is, when a temperature at which the sprayed particle size of the waste edible oil can be set to a combustible particle size, the temperature switch 54 is activated to A combustion controller (not shown) starts a combustion operation.

  First, the waste edible oil is pressurized for a predetermined time by the spray pump 44, and the pressure of the waste edible oil becomes equal to or higher than the passage pressure of the drip-proof valve 14a, and the waste edible oil is sprayed from the spray nozzle 14b. Next, the sprayed waste cooking oil is directly ignited by the electric spark of the spark plug 81.

  After this ignition, the flow control motor operated valve 51 and the damper 72 are controlled according to the load.

  In this way, in the present embodiment, the waste edible oil is heated to 90 ° C. to 110 ° C. and supplied to the waste edible oil supply unit 10 for pressure spraying, so that it can be burned in the same manner as A heavy oil. . Therefore, waste edible oil can be used as an effective fuel source.

  Hereinafter, the present invention will be described more specifically by way of examples.

Reference Example The return type pressure spray burner B of this embodiment is used to spray heavy oil A at 25 ° C. (normal temperature) at an appropriate spray pressure (1.8 MPa), and the spray particle size and particle size distribution are measured. The results are shown in FIG. 4 as a reference example.

Example Spraying was performed in the same manner as in the Reference Example except that the supply to the return type pressure spray burner B was changed to waste cooking oil and the temperature was changed to 110 ° C., and the spray particle size and particle size distribution were measured. The results are also shown in FIG. 4 as an example.

Comparative Example Spraying was performed in the same manner as in the Example except that the temperature of the waste edible oil was set to 80 ° C., and the spray particle size and particle size distribution were measured. The results are also shown in FIG. 4 as a comparative example.

  FIG. 4 shows that the spray characteristics similar to those of the reference example are obtained in the example.

  The present invention can be applied to combustion of waste cooking oil using a pressure spray burner.

It is the schematic of the return type pressure spray type burner applied to the combustion method of the waste edible oil which concerns on one Embodiment of this invention. FIG. 2 is a system diagram around a combustion apparatus applied to the combustion method. It is sectional drawing of the supply / discharge block of the burner. It is a graph which shows the spraying characteristic of an Example, a comparative example, and a reference example. It is the schematic of the conventional return type pressure spray type burner.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Waste cooking oil supply part 10A Double pipe 11 Inner pipe, Supply pipe 12 Outer pipe, Return pipe 13 Supply / discharge block 14 Spray block 14a Drip-proof valve 14b Spray nozzle 20 Air supply part 43 Air separator 44 Heater 45 Spray pump (Pressure-feeding means)
54 Temperature switch 71 Blower 72 Damper (air flow control valve)
A Combustor B Return type pressure spray burner F Fuel system FA Combustion air system

Claims (5)

The cooking oil Ri by the pressure atomizing type burner comprising a combustion method for burning as with A heavy oil,
A procedure for increasing the pressure of waste cooking oil supplied to the burner to 1.8 MPa to 2.5 MPa ;
A procedure for raising the temperature of the edible cooking oil supplied to the burner to 90 ° C. to 110 ° C . ;
A procedure for increasing the amount of the waste cooking oil by a predetermined amount and supplying it to the spray nozzle;
Procedure for preventing cooling by combustion air of waste edible oil supplied to the spray nozzle while returning the increased amount of waste edible oil to the supply side, and maintaining the waste edible oil supplied to the spray nozzle at the temperature And a method for combusting waste cooking oil. The method for combusting waste edible oil according to claim 1, wherein the ratio of waste edible oil returned to the supply side is at least three times that of the waste edible oil to be sprayed. A combustion apparatus for burning waste cooking oil in the same manner as heavy oil A by a pressure spray burner,
Said burner, and a pipe for supplying the cooking oil to the spray nozzle, the temperature of the cooking oil to be supplied to the spray nozzle while back to the feed side part of the waste edible oil, the cooling by the combustion air A combustion apparatus for waste edible oil, comprising a heat insulation outer tube that prevents and maintains at 90 ° C. to 110 ° C. The combustion apparatus for waste edible oil according to claim 3 , further comprising a heater for raising the temperature of the edible edible oil to the temperature. A pressure atomizing burner to be applied to the combustion method according to claim 1 or 2, and the pipe for supplying the cooking oil to the spray nozzle, spray with return to the supply side of the portion of the waste edible oil A pressure spray burner comprising: a heat insulation outer tube that maintains a temperature of waste edible oil supplied to the nozzle at 90 ° C. to 110 ° C. while preventing cooling by combustion air .

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