JP2019070482A - Hot air generation device and dryer - Google Patents

Abstract

To provide a hot air generation device which can introduce outer air into an outer air supply passage uniformly.SOLUTION: A hot air generation device includes: a mixing chamber; a combustion furnace 5 for generating hot air by a burner to supply the hot air to the mixing chamber; an outer air supply passage R2 communicating with the mixing chamber and extending in a predetermined direction; and an outer air introduction passage R3 for introducing outer air W2 and supplying the outer air to the outer air supply passage R2. The outer air W2 introduced into the outer air introduction passage R3 flows through the outer air supply passage R2 in the predetermined direction and flows into the mixing chamber to be mixed with the hot air and generate mixed air. The outer air introduction passage R3 has a spiral shape in which a cross sectional area gradually reduces from the upstream side to the downstream side.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a hot air generator and a dryer provided with the same.

  Conventionally, a drier for drying a material to be dried such as cereals, vegetables and fresh okara has been proposed (see, for example, Patent Document 1). As such a dryer, a mixture obtained by mixing the hot air generated by igniting the burner with the combustion furnace and the outside air guided to the outer periphery of the combustion furnace is sent as a drying gas to the drying chamber, It has been proposed to dry the material to be dried.

  FIG. 6 shows a conventional hot air generator 102 used in such a dryer. In the hot air generating apparatus 102, an outer air supply passage R2 having a circular vertical cross section is provided on the outer periphery of the combustion furnace 105, and a plurality of inlets 100 are provided on the rear surface of the combustion furnace 105. The outside air W1 is introduced into the outside air supply path R2 from the inlet 100, flows into the mixing chamber R1, and is mixed with the hot air W2 from the combustion furnace 105 to generate a mixture W3.

Patent document 1: JP-A-2002-350057

  The conventional hot air generator 102 shown in FIG. 6 has a problem that the air volume of the outside air W1 flowing through the outside air supply path R2 is not uniform in the circumferential direction. That is, in the portion of the outside air supply passage R2 exposed to the outside through the introduction hole 100 and the portion where the rear end is closed by the rear surface of the combustion furnace 105, the amount of air flowing through the outside air supply passage R2 is There was a variation.

  An object of this invention is to provide the hot-air generator which can introduce | transduce external air uniformly into an external air supply route, and a dryer provided with the same.

  Another object of the present invention is to provide a hot air generator capable of easily controlling the temperature inside the combustion furnace and a dryer provided with the same.

  The hot air generating apparatus according to the present invention includes a mixing chamber, a combustion furnace for generating hot air by a burner and supplying the same to the mixing chamber, an outside air supply passage communicating with the mixing chamber and extending in a predetermined direction, and introducing the outside air. Outside air introduced to the outside air supply path, the outside air introduced into the outside air introduction path flows through the outside air supply path in the predetermined direction, flows into the mixing chamber, and mixes with the hot air It is characterized in that the air-fuel mixture is generated, and the outside air introduction path is in a spiral shape whose cross-sectional area gradually decreases as going from the upstream side to the downstream side.

  Further, the hot air generating apparatus according to the present invention further comprises a control unit for controlling the burner, and a temperature sensor for detecting an internal temperature of the combustion furnace, wherein the burner includes a first fuel injection nozzle, And, when the internal temperature of the combustion furnace measured by the temperature sensor rises to a first temperature, the control unit keeps the first fuel injection nozzle turned on while the second fuel is on. The control unit may turn on the second fuel injection nozzle when the injection nozzle is turned off and the internal temperature of the combustion furnace measured by the temperature sensor falls to a second temperature lower than the first temperature. I assume.

  According to the hot air generating apparatus of the present invention, since the outside air introducing passage has a spiral shape whose cross-sectional area gradually decreases as going from the upstream side to the downstream side, the outside air passing through the outside air introducing passage becomes a free vortex and the pressure is constant. Continue to accelerate as you go downstream. Therefore, even if there is only one connection port from which the outside air flows into the outside air supply path from the outside air introduction path, the outside air uniformly spreads over the entire circumference of the outside air supply path and flows toward the mixing chamber without deviation in the outside air supply path. .

  In addition, when the internal temperature of the combustion furnace rises to a first temperature, the control unit turns off the second fuel injection nozzle while the first fuel injection nozzle is turned on, and the internal temperature of the combustion furnace is Since the second fuel injection nozzle is turned on when the temperature drops to a second temperature lower than 1 temperature, the internal temperature of the combustion furnace is lower than that when all the fuel injection nozzles are turned off when the first temperature is reached. It can prevent falling too much. Further, since the temperature control inside the combustion furnace is performed only by the on / off control of the fuel injection nozzle, the configuration relating to the temperature control inside the combustion furnace can be simplified. Furthermore, since the internal temperature of the combustion furnace is prevented from rising more than necessary, fuel efficiency can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic front view of the dryer which concerns on embodiment of this invention. The longitudinal cross-sectional view of the hot-air generator with which the dryer shown in FIG. 1 is provided. III-III sectional view taken on the line of FIG. FIG. 2 is a block diagram showing a configuration of a dryer shown in FIG. The flowchart which shows the control processing performed in the dryer shown in FIG. It is a figure which shows the conventional hot-air generator, Comprising: (a) is a longitudinal cross-sectional view, (b) is a rear view.

  Hereinafter, a dryer according to an embodiment of the present invention will be described with reference to the attached drawings. As shown in FIG. 1, the dryer 1 of the present embodiment includes a hot air generator 2 for generating a drying gas, a drying oven 3 connected to the hot air generator 2, and a duct 4 extending from the drying oven 3. And an induction fan (not shown) provided in the duct 4, the drying gas generated by the hot air generator 2 is drawn into the drying furnace 3 by the induction fan, and the material to be dried (not shown) is It is configured to dry.

  As shown in FIGS. 2 and 3, the hot air generating device 2 is mounted on a cylindrical combustion furnace 5 extending in the front-rear direction (predetermined direction) D1, a frame 6 accommodating the combustion furnace 5, and the frame 6 The mixing chamber R 1 is provided in front of the combustion furnace 5. Inside the combustion furnace 5, a combustion chamber 51 extending in the front-rear direction D1 is provided. A hot air outlet 52 is provided in front of the combustion chamber 51 (the front end of the combustion furnace 5), and the combustion chamber 52 is in communication with the mixing chamber R1 via the hot air outlet 52. A burner insertion port 53 is provided at the rear of the combustion chamber 51, and the burner 9 (FIG. 4) is inserted and attached thereto. When the burner 9 is ignited, a hot air (combustion gas) W1 is generated, and thus the hot air W1 generated in the combustion furnace 5 is blown out from the combustion chamber 51 to the mixing chamber R1 via the hot air outlet 52.

  On the outer periphery of the combustion furnace 5, an external air supply passage R2 having an annular vertical cross section is provided. A vortex-like outside air introduction passage R3 is formed in the ventilation box 7, and one end (inner end) of the outside air introduction passage R3 communicates with the rear portion of the outside air supply passage R2. The outside air W2 is introduced into the outside air introduction passage R3 by the action of the induction fan, and the outside air W2 introduced in this manner flows into the mixing chamber R1 through the outside air supply passage R2 and mixes with the hot air W1 generated in the combustion furnace 5. As a result, a mixture gas W3 as a drying gas is obtained. By mixing the high-temperature hot air W1 generated by the combustion furnace 5 with the ambient air W2 at room temperature as described above, it is possible to generate the mixture gas W3 at a temperature suitable for drying the material to be dried.

  The outside air introduction path R3 will be described in detail. The outside air introduction passage R3 is located on the outer periphery of the outside air supply passage R2 and has a spiral shape whose cross-sectional area gradually decreases as it goes from the upstream side to the downstream side, and the distance from the spiral center axis C gradually decreases as it goes downstream. Further, the swirl center axis C of the outside air introduction passage R3 extends in the front-rear direction D1. As described above, by adopting a spiral shape in which the cross-sectional area gradually decreases toward the downstream side, the outside air passing through the outside air introduction passage R3 becomes a free vortex, and the pressure remains constant and accelerates toward the downstream side.

  Further, the outside air flowing in a swirling manner along the outside air introduction passage R3 flows into the outside air supply passage R2 along the inner surface of the outside air supply passage R2. Therefore, even if there is one connection port P from which the outside air flows from the outside air introduction passage R3 into the outside air supply passage R2, the outside air uniformly spreads over the entire circumferential direction of the outside air supply passage R2 having an annular cross section, and the inside of the outside air supply passage R2 Flow toward the mixing chamber R1 without bias.

  The drier 1 further includes an adjusting tool 8, and the adjusting tool 8 includes a baffle plate 81 provided in the mixing chamber R 1 opposite to the hot air outlet 52 and a pipe member 82 as an operation part fixed to the baffle plate 81. And. The rear end of the tube member 82 is fixed to the baffle plate 81, and the front end of the tube member 82 extends outward of the mixing chamber R1 (frame 6). Therefore, the operator holds the front end portion of the tube member 82 to move the entire adjustment tool 8 in the front-rear direction D1, and manually adjusts the gap (gap G) between the baffle plate 81 and the combustion furnace 5 The pressure in the combustion chamber 51 can be adjusted by adjusting the gap G. In addition, the lid member 83 is detachably attached to the front opening 82a of the tube member 82, and the operator can visually observe the inside of the combustion chamber 51 via the tube member 82 by removing the lid member 83. it can.

  Thus, the mixture W3 generated in the mixing chamber R1 is attracted to the drying chamber (not shown) of the drying furnace 3 by the action of the above-described attraction fan (not shown), and to the outside through the duct 4 The material to be dried in the drying chamber is dried as the mixture W3 is discharged and passes through the drying chamber.

  As described above, according to the dryer 1 according to the present embodiment, the outside air is introduced into the outside air supply passage R2 via the spiral outside air introduction passage R3, so that the outside air can be uniformly taken into the air supply passage R2. It is possible to suppress the occurrence of uneven drying.

  Referring to FIG. 4, the hot air generator 2 is further provided with a control unit 10 for controlling the burner 9 and an internal temperature of the combustion furnace 5 installed in the combustion furnace 5 (ie, a temperature of the hot air W2 / combustion chamber 51 A temperature sensor 11 for detecting the room temperature of The burner 9 has first and second nozzles (fuel injection nozzles) 91 and 92, and the control unit 10 performs on / off control of the second nozzle 92 based on the temperature detected by the temperature sensor 11, and determines the temperature of the hot air W2 Maintain within the temperature range of

  The control control which the control part 10 performs is demonstrated with reference to the flow chat of FIG. The control process shown in FIG. 5 is started when the ignition command of the burner 9 is received by the operation of the operation switch (not shown). When the control process starts, first, the burner 9 is ignited (S1). At this time, the first and second nozzles 91 and 92 are both turned on to inject fuel.

  When the internal temperature of the combustion furnace 5 rises to the first temperature (S3: YES), the second nozzle 92 is turned off (S5), and the combustion is continued only with the first nozzle 91. Then, the internal temperature of the combustion furnace 5 starts to fall gradually. Then, when the internal temperature of the combustion furnace 5 falls to the second temperature lower than the first temperature (S7: YES), the second nozzle 92 is turned on again (S9), and the first and second nozzles 91, 92 are turned on. The combustion using both sides is restarted, and it returns to S3.

  Thereby, the internal temperature of the combustion furnace 5 is maintained in the predetermined temperature range between the first temperature and the second temperature. Thus, in the present embodiment, the internal temperature management of the combustion furnace 5 is performed only by the on / off control of the second nozzle 92, and the first nozzle 91 is maintained in the on state regardless of the internal temperature of the combustion furnace 5. Ru. Therefore, it is possible to prevent the internal temperature of the combustion furnace 5 from being excessively lowered, as compared with the control in which all the nozzles are turned off when the internal temperature of the combustion furnace 5 reaches the first temperature. That is, when all the nozzles are turned off, the internal temperature of the combustion furnace 5 continues to fall during this time because it has a certain time until it actually fires even if it is turned on again when the temperature drops to the second temperature. Become. In this respect, in the present embodiment, since the first nozzle 91 is continuously turned on without turning off even when the first temperature is reached, the decrease rate of the internal temperature of the combustion furnace 5 is relatively slow. The internal temperature of the combustion furnace 5 can be prevented from falling excessively, and drying of the material to be dried can be performed uniformly.

  As mentioned above, although the dryer concerning the embodiment of the present invention was explained with reference to an attached drawing, the present invention is not limited to this embodiment, various modification and correction are possible without departing from the scope of the present invention It is.

  For example, although the burner 9 includes the two nozzles 91 and 92 in the above embodiment, the number of nozzles provided in the burner 9 is not limited to two, and may be three or more. In this case, the number of nozzles to be always on may be one or plural, and the number of nozzles on / off controlled by the internal temperature of the combustion furnace 5 is also plural even if one. It is sufficient to keep the on state for at least one nozzle, and perform on / off control based on the detected temperature for the remaining one or more nozzles.

DESCRIPTION OF SYMBOLS 1 dryer 3 drying furnace 4 duct 5 combustion furnace 51 combustion chamber 52 hot air blower outlet R1 mixing chamber R2 outside air supply passage R3 outside air introduction passage W1 hot air W2 outside air W3 mixture (gas for drying)

Claims (5)

With a mixing chamber,
A combustion furnace for generating hot air by a burner and supplying it to the mixing chamber;
An external air supply passage communicating with the mixing chamber and extending in a predetermined direction;
An outside air introduction path for introducing outside air and supplying it to the outside air supply path;
Hot air generated by the combustion furnace is supplied to the mixing chamber through a hot air outlet of the combustion furnace,
The outside air introduced into the outside air introduction passage flows in the outside air supply passage in the predetermined direction, flows into the mixing chamber, and is mixed with the hot air to generate an air-fuel mixture,
The hot air generator according to claim 1, wherein the outside air introduction path has a spiral shape whose cross-sectional area gradually decreases as it goes from the upstream side to the downstream side.   The hot air generator according to claim 1, wherein a spiral central axis of the spiral external air introduction path is parallel to the predetermined direction. The outside air supply passage is provided on the outer periphery of the combustion furnace and has an annular longitudinal cross section,
The hot air generating device according to claim 1, wherein the outside air introduction path is provided on an outer periphery of the outside air supply path. A control unit for controlling the burner;
And a temperature sensor for detecting the internal temperature of the combustion furnace,
The burner has a first fuel injection nozzle and a second fuel injection nozzle,
When the internal temperature of the combustion furnace measured by the temperature sensor rises to a first temperature, the control unit turns off the second fuel injection nozzle while keeping the first fuel injection nozzle on,
The control unit turns on the second fuel injection nozzle when the internal temperature of the combustion furnace measured by the temperature sensor falls to a second temperature lower than the first temperature. The hot-air generator in any one of -3. A hot air generator for generating a drying gas;
And a drying chamber for drying the material to be dried by the drying gas from the hot air generator.
The hot air generator is a hot air generator according to any one of claims 1 to 4,
The dryer is characterized in that the mixture is supplied to the drying chamber as the drying gas.

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