Drying equipment

Abstract

To provide a dryer capable of reducing frequency of abnormal stop and improving convenience of a user.SOLUTION: In a drying device 1, after starting combustion by a burner 50 with a supply amount of a fuel gas set to a first flow rate FR1, a control part 3 executes first determination steps S110-S119 for determining whether or not it is a first state where a supply air temperature rises up to a first temperature SH2 shorter than a first time T1. In the case of determining that it is the first state, the control part 3 changes the supply amount to a second flow rate FR2 smaller than the first flow rate FR1, and based on the degree of the supply air temperature dropping, executes second determination steps S120-S128 for determining whether or not it is blockage abnormality in which exhaustion of a mixed gas from a drying chamber 81 is abnormal. In the case of determining the blockage abnormality, the control part 3 executes at least one of a notification step S130 and a stop step S131.SELECTED DRAWING: Figure 3

Description

Technical Field

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[0001] The present invention relates to a drying device.

Background Art

[0002] Patent Document 1 discloses a gas clothes dryer which is an example of a conventional drying device. This gas clothes dryer includes a gas burner, a drum, a hot air duct, a fan, an exhaust port, a temperature detection sensor, and a control unit.

[0003] The gas burner takes in air and burns the fuel gas supplied from the outside to generate a high-temperature mixed gas in which combustion exhaust gas and air are mixed. The drum houses clothes. The hot air duct guides the mixed gas from the gas burner to the drum.

[0004] The fan supplies the mixed gas to the drum. A filter is provided on the drum side of the fan. The exhaust port discharges the mixed gas from the drum. The temperature detection sensor measures the supply air temperature of the mixed gas in the hot air duct. The control unit controls the gas burner and the fan and acquires the supply air temperature measured by the temperature detection sensor.

[0005] After starting the combustion by the gas burner, the control unit calculates the rising gradient of the supply air temperature within a certain time by a monitoring circuit. When this rising gradient exceeds the set value, it determines an abnormal clogging of the filter and drives an alarm circuit.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

[0008] However, in this case, it becomes easy to mistakenly judge that there is a blockage problem when there is none. As a result, it is difficult to reduce the frequency of abnormal shutdowns with this drying device, and it is difficult to improve user convenience.

[0009] This invention has been made in view of the above-mentioned conventional circumstances, and aims to solve the problem of providing a drying apparatus that can reduce the frequency of abnormal shutdowns and improve user convenience. [Means for solving the problem]

[0010] The drying apparatus of the present invention includes a fuel supply device that supplies fuel gas, A burner that takes in air and burns the fuel gas supplied from the fuel supply device to generate a high-temperature mixed gas of combustion exhaust and air, A drying chamber for containing the material to be dried, An air supply passage that guides the mixed gas from the burner to the drying chamber, A blower fan that supplies the mixed gas to the drying chamber, An exhaust passage for discharging the mixed gas from the drying chamber, A temperature measuring device for measuring the supply air temperature of the mixed gas within the supply air passage, A control unit that controls the fuel supply device, the burner, and the blower fan, and acquires the supply air temperature measured by the temperature measuring device, Equipped with, The control unit starts combustion by the burner with the fuel gas supply amount set to a first flow rate, and then performs a first determination step to determine whether or not the supply air temperature is in a first state where it rises to a first temperature in less than a first hour. If the control unit determines that the first state is present, it changes the supply amount to a second flow rate which is less than the first flow rate, and performs a second determination step to determine whether or not there is an abnormal blockage in the discharge of the mixed gas from the drying chamber, based on the degree to which the supply air temperature decreases. The control unit is configured to perform at least one of the following steps when it determines that there is an abnormal blockage: a notification step of notifying the abnormal blockage, and a stop step of stopping the fuel supply device and the burner.

[0011] In the drying apparatus of the present invention, the exhaust passage may become blocked, for example, due to clogging of the filter located on the drying chamber side of the exhaust passage, blockage of the exhaust duct located on the outdoor side of the exhaust passage by foreign matter, or strong wind blowing into the exhaust duct. In this case, a blockage abnormality occurs, resulting in abnormal discharge of the mixed gas from the drying chamber.

[0012] If the control unit determines in the first decision step that the first state is present, that is, if it determines that the intake air temperature is rising to a large extent, it does not immediately determine that there is an obstruction abnormality, but instead executes the second decision step.

[0013] Here, the control unit utilizes the fact that when the exhaust passage blockage rate increases, even a slight difference in the blockage rate results in a clear difference that causes the supply air temperature to decrease.

[0014] In other words, if the difference indicating whether or not there is an obstruction is not clear when the intake air temperature is rising, the control unit lowers the intake air temperature in the second judgment step by changing the fuel gas supply amount to a second flow rate that is less than the first flow rate. Then, the control unit determines whether or not there is an obstruction when the difference in the degree to which the intake air temperature decreases becomes clear.

[0015] As a result, the control unit can prevent it from mistakenly determining that there is no blockage when there is, or vice versa.

[0016] Therefore, the drying device of the present invention can reduce the frequency of abnormal stops and improve the convenience for users.

[0017] Furthermore, this drying device can suppress damage to the object to be dried by the high-temperature mixed gas through the second determination step executed by reducing the supply amount of fuel gas.

[0018] The control unit measures the rising gradient of the air supply temperature in the first determination step. When the rising gradient is greater than or equal to the abnormal determination value, it determines that there is a blockage abnormality, ends the first determination step, and without executing the second determination step, it is desirable to execute at least one of the notification step and the stop step.

[0019] In this case, when the air supply temperature rises excessively, the control unit determines that it is better not to continue combustion by the burner, so that at least one of the notification step and the stop step can be executed quickly. As a result, this drying device can suppress problems caused by blockage abnormalities.

[0020] The control unit measures the rising gradient of the air supply temperature in the first determination step. When the rising gradient is less than or equal to the normal determination value, it determines that there is no blockage abnormality, ends the first determination step, and it is desirable not to execute the second determination step.

[0021] In this case, it is possible to suppress reducing the gas supply amount in the second determination step even though there is no blockage abnormality, so the drying time is not likely to become long.

Advantages of the Invention

[0022] According to the drying device of the present invention, the frequency of abnormal stops can be reduced and the convenience for users can be improved.

Brief Description of the Drawings

[0023] [Figure 1] FIG. 1 is a schematic cross-sectional view of a clothes dryer according to an embodiment. [Figure 2]Figure 2 is a flowchart of the blockage abnormality detection program for the clothes dryer of the embodiment. [Figure 3] Figure 3 is a flowchart of the blockage abnormality detection program for the clothes dryer of the embodiment. [Figure 4] Figure 4 is a graph showing the change in supply air temperature after combustion by the burner has started, and it is a graph that explains the first decision step. [Figure 5] Figure 5 is a graph showing the change in intake air temperature after combustion by the burner has started, and it is a graph that explains the second decision step. [Modes for carrying out the invention]

[0024] The following describes embodiments of the present invention with reference to the drawings.

[0025] (Examples) As shown in Figure 1, the clothes dryer 1 of the embodiment is an example of a specific embodiment of the drying apparatus of the present invention. The clothes dryer 1 is a gas clothes dryer that dries clothes by burning fuel gas and using a high-temperature mixed gas obtained by mixing combustion exhaust and air. The clothes dryer 1 comprises a housing 8, a rotating drum 80, and a door 89.

[0026] In this embodiment, the side of the enclosure 8, which is roughly box-shaped, on which the door 89 is located is defined as the front side of the enclosure 8, and the side of the enclosure 8 opposite to the side on which the door 89 is located is defined as the rear side of the enclosure 8.

[0027] A clothing input opening 88 is provided on the front of the housing 8. The inner edge of a roughly annular ring plate 87 is joined to the edge of the clothing input opening 88 that is located inside the housing 8. A communication hole 87A is formed in the lower part of the ring plate 87.

[0028] A drum support shaft 80S is fixed to the rear wall of the housing 8, with the rotation axis X80 as its center. The rotation axis X80 extends horizontally in the front-to-back direction of the housing 8. The drum support shaft 80S protrudes toward the front of the housing 8.

[0029] The rotating drum 80 is housed inside the housing 8. The rotating drum 80 has a cylindrical portion 84 and a rear wall portion 82. The cylindrical portion 84 is cylindrical in shape with the rotation axis X80 as its center. The rear wall portion 82 is substantially disc-shaped and connects to the edge of the cylindrical portion 84 located on the rear side of the housing 8.

[0030] The rotating drum 80 forms a drying chamber 81 for accommodating clothing CL1 through its cylindrical portion 84 and back wall portion 82. Clothing CL1 is an example of the "item to be dried" in this invention. The back wall portion 82 is provided with a ventilation portion 83. The ventilation portion 83 consists of a plurality of holes and a filter 83F covering each hole.

[0031] The rotating drum 80 is rotatable around the rotation axis X80 because its rear wall portion 82 is rotatably supported by a drum support shaft 80S, and the end edge of the cylindrical portion 84 located on the front side of the housing 8 is rotatably supported by the outer peripheral edge of the ring plate 87.

[0032] The door 89 is supported on the front side of the housing 8 so as to be able to swing between a closed position and an open position. When the door 89 is in the closed position, it covers the clothes input opening 88 and closes the drying chamber 81. On the other hand, when the door 89 is in the open position, it moves away from the clothes input opening 88 and opens the drying chamber 81.

[0033] A motor 60 is provided below the rotating drum 80 within the housing 8. The motor 60 has a first drive shaft 61 and a second drive shaft 62 centered on a drive axis X60 parallel to the rotation axis X80. The first drive shaft 61 protrudes toward the front side of the housing 8. The second drive shaft 62 protrudes toward the rear side of the housing 8.

[0034] A first pulley 61P is fixed to the first drive shaft 61 so as to be able to rotate as an integral part of it. A first transmission belt 61B is wrapped around the first pulley 61P and the cylindrical portion 84 of the rotating drum 80.

[0035] When the motor 60 operates and generates driving force, the driving force is transmitted to the cylindrical section 84 via the first drive shaft 61, the first pulley 61P, and the first transmission belt 61B, causing the rotating drum 80 to rotate around the rotation axis X80. The rotation of the rotating drum 80 is performed to keep the clothes CL1 contained in the drying chamber 81 constantly moving without being stopped in a fixed position.

[0036] The clothes dryer 1 is equipped with an air intake port 71, an air intake passage 72, an exhaust port 75, an exhaust passage 76, a blower fan 78, a fuel supply device 53, and a burner 50.

[0037] The air intake port 71 is a series of holes drilled through the bottom wall of the housing 8. The air intake passage 72 is located on the front side and bottom wall side within the housing 8. An inlet 72A is formed in the air intake passage 72. The inlet 72A is located above and forward of the air intake port 71 within the housing 8 and is connected to the combustion chamber 50B of the burner 50, which will be described later. The air intake passage 72 extends upward from the inlet 72A, and its upper end is connected to the communication hole 87A of the ring plate 87.

[0038] The exhaust port 75 is a hole drilled through the upper wall of the housing 8, on the rear side of the housing 8 relative to the rotating drum 80. The exhaust passage 76 is provided between the rear wall portion 82 of the rotating drum 80 and the rear wall of the housing 8. An outlet 76A is formed in the exhaust passage 76. The outlet 76A opens widely forward within the housing 8, facing the ventilation portion 83 of the rear wall portion 82. The exhaust passage 76 extends upward from the outlet 76A, and its upper end is connected to the exhaust port 75.

[0039] An exhaust duct 75D is connected to the exhaust port 75. The exhaust duct 75D is connected to a through-hole formed in the exterior wall of the house where the clothes dryer 1 is installed.

[0040] The blower fan 78 is located within the exhaust passage 76. The blower fan 78 is fixed to a cylindrical fan support 78S, which is externally fitted to the drum support shaft 80S, so as to be able to rotate integrally with the blower fan 78, facing the ventilation portion 83 of the back wall portion 82. This allows the blower fan 78 to rotate around the rotation axis X80.

[0041] A second pulley 62P is fixed to the second drive shaft 62 of the motor 60 so as to be able to rotate together with it. A second transmission belt 62B is wrapped around the second pulley 62P and the fan support 78S.

[0042] When the motor 60 operates and generates driving force, the driving force is transmitted to the fan support 78S via the second drive shaft 62, the second pulley 62P, and the second transmission belt 62B, causing the blower fan 78 to rotate around the rotation axis X80.

[0043] The fuel supply device 53 and the burner 50 are located above the air intake port 71 and behind the air intake passage 72 inlet 72A.

[0044] The fuel supply device 53 supplies fuel gas to the burner 50 by injecting fuel gas supplied from a gas supply source (not shown) from a gas injection nozzle 51 toward the gas inlet 50A of the burner 50.

[0045] The burner 50 takes in air entering the housing 8 from the air intake port 71 and burns the fuel gas supplied from the fuel supply device 53 in the combustion chamber 50B, generating a high-temperature mixed gas of combustion exhaust and air.

[0046] With the burner 50 not ignited, the motor 60 operates and the blower fan 78 rotates, causing the air in the drying chamber 81 to be discharged to the outside of the housing 8 via the vent 83, exhaust passage 76, and exhaust port 75. This creates negative pressure inside the drying chamber 81, and the air entering the housing 8 from the air intake port 71 is supplied to the drying chamber 81 via the combustion chamber 50B, air intake passage 72, and communication hole 87A, circulates within the drying chamber 81, and is then discharged to the outside of the housing 8 via the vent 83, exhaust passage 76, and exhaust port 75.

[0047] In this state, when the burner 50 ignites and generates a high-temperature mixed gas, the air supply passage 72 guides the mixed gas from the combustion chamber 50B of the burner 50 to the drying chamber 81, and the blower fan 78 supplies the mixed gas to the drying chamber 81. The high-temperature mixed gas then circulates within the drying chamber 81 and absorbs moisture from the clothing CL1. After that, the exhaust passage 76 discharges the mixed gas from the drying chamber 81 to the outside of the housing 8.

[0048] The clothes dryer 1 is equipped with an air supply temperature sensor S1. The air supply temperature sensor S1 is an example of the "temperature measuring device" of the present invention. The air supply temperature sensor S1 is located near the communication hole 87A in the air supply passage 72. The air supply temperature sensor S1 measures the air supply temperature of the mixed gas in the air supply passage 72.

[0049] The clothes dryer 1 has a control unit 3. The control unit 3 is housed in a position below the door 89 on the front of the housing 8.

[0050] The control unit 3 is an electronic circuit unit composed of a CPU, ROM, RAM, and interface circuits (not shown). The ROM stores programs for executing various operations of the clothes dryer 1, such as drying. For example, the ROM stores the "blockage abnormality detection program" shown in Figures 2 and 3. The RAM is used as a storage area for temporarily recording data and signals used by the CPU when executing the above program, or as a working area for data processing.

[0051] The control unit 3 controls the motor 60 that drives the blower fan 78, the fuel supply device 53, the burner 50, etc., and acquires the supply air temperature measured by the supply air temperature sensor S1, and performs a drying operation to dry the clothes CL1 stored in the drying chamber 81.

[0052] As shown in Figure 1, the clothes dryer 1 has an input unit 3E and a display unit 3D. The input unit 3E and the display unit 3D are positioned below the door 89 on the front of the housing 8 so as to be exposed.

[0053] The input unit 3E has multiple buttons, including a power button, a start button to instruct the start of drying operations, and buttons for numerical input and selection of various modes. Various operations performed by the user on the input unit 3E are transmitted to the control unit 3 and reflected in the control of drying operations, etc.

[0054] The display unit 3D consists of multiple 7-segment LEDs, liquid crystal displays, interlocking LED lamps, etc., arranged in a row. The display unit 3D is controlled by the control unit 3 and displays various information and error messages regarding the operating status of the clothes dryer 1.

[0055] <Obstruction Abnormality Detection Program> In the clothes dryer 1 of the embodiment, the exhaust passage 76 may become blocked, for example, due to clogging of the filter 83F located on the drying chamber 81 side of the exhaust passage 76, blockage of foreign matter in the exhaust duct 75D located on the outdoor side of the exhaust passage 76, or strong wind blowing into the exhaust duct 75D. In this case, a blockage abnormality occurs, resulting in abnormal discharge of the mixed gas from the drying chamber 81.

[0056] When the user operates the input unit 3E to instruct the start of the drying operation, the control unit 3 starts the drying operation and executes the "blockage abnormality detection program" shown in Figures 2 and 3.

[0057] First, in step S101 shown in Figure 2, the control unit 3 activates the motor 60 to start the rotation of the drying drum 80 and the blower fan 78. In this embodiment, the rotation speed of the drying drum 80 is constant at a preset speed. The same applies to the blower fan 78.

[0058] Next, the control unit 3 moves to step S102 and starts supplying fuel gas by the fuel supply device 53 with the fuel gas supply amount set to the first flow rate FR1. The first flow rate FR1 is preset. Then, the control unit 3 ignites the burner 50 and starts combustion by the burner 50, and also starts timing with the timer.

[0059] As a result, the air intake passage 72 guides the mixed gas from the combustion chamber 50B of the burner 50 to the drying chamber 81, and the air intake temperature measured by the air intake temperature sensor S1 rises. The control unit 3 continuously acquires the air intake temperature measured by the air intake temperature sensor S1.

[0060] Next, the control unit 3 proceeds to step S110, starts the first decision step, and executes steps S111 to S115. Steps S111 to S115 are processes for measuring the upward gradient US1 of the supply air temperature.

[0061] As shown in Figure 4, in this embodiment, the rising gradient measurement start temperature SH1 and the rising gradient measurement end temperature SH2 (>SH1) are set in advance. The rising gradient measurement end temperature SH2 is an example of the "first temperature" of the present invention.

[0062] The start time ST1 for measuring the upward gradient when the supply air temperature rises to the starting temperature SH1, and the end time ST2 for measuring the upward gradient when the supply air temperature rises to the end temperature SH2, vary depending on the blockage rate of the exhaust passage 76.

[0063] The difference between the end time ST2 of the upward gradient measurement and the start time ST1 of the upward gradient measurement (L1 and L2, shown as an example in Figure 4) decreases as the blockage rate of the exhaust passage 76 increases.

[0064] Note that in Figure 4, for the sake of simplicity, the fluctuation patterns E1, N1, J1, and J2 are shown linearly as an example of a fluctuation pattern of supply air temperature; however, the actual fluctuation pattern of supply air temperature may not necessarily be linear.

[0065] When the control unit 3 proceeds to step S111 shown in Figure 2, it determines whether the supply air temperature has risen to the rising gradient measurement start temperature SH1, and repeats step S111 until it determines "Yes".

[0066] Then, if the control unit 3 answers "Yes" in step S111, it proceeds to step S112 and stores the rise gradient measurement start time ST1 when the supply air temperature rises to the rise gradient measurement start temperature SH1.

[0067] Next, the control unit 3 proceeds to step S113, where it determines whether the supply air temperature has risen to the rising gradient measurement end temperature SH2, and repeats step S113 until it determines "Yes".

[0068] Then, if the control unit 3 answers "Yes" in step S113, it proceeds to step S114 and stores the time ST2 when the rising gradient measurement is completed, which is when the supply air temperature has risen to the rising gradient measurement completion temperature SH2.

[0069] Next, the control unit 3 proceeds to step S115 and calculates the upward gradient US1 of the supply air temperature. The upward gradient US1 is the value obtained by dividing the difference between the upward gradient measurement end temperature SH2 and the upward gradient measurement start temperature SH1 by the difference between the upward gradient measurement end time ST2 and the upward gradient measurement start time ST1 (US1 = (SH2 - SH1) / (ST2 - ST1)). The upward gradient US1 is a positive value, and it becomes larger as the obstruction rate of the exhaust passage 76 increases.

[0070] Next, the control unit 3 proceeds to step S116 and determines whether the upward slope US1 is greater than or equal to the abnormality determination value G1.

[0071] The region on fluctuation pattern E1 shown by a solid line in Figure 4, and the region located to the left of fluctuation pattern E1 in Figure 4, are regions that should be clearly judged as having an obstruction abnormality. In this embodiment, the abnormality judgment value G1 is the upward slope US1 of fluctuation pattern E1 (US1 = (SH2 - SH1) / (ST2(E) - ST1(E))).

[0072] If the control unit 3 responds "Yes" in step S116 shown in Figure 2, it proceeds to step S128 shown in Figure 3. The processing from step S128 onward will be described later.

[0073] On the other hand, if the control unit 3 determines "No" in step S116 shown in Figure 2, it proceeds to step S117. The control unit 3 then determines whether the upward slope US1 is equal to or greater than the normal determination value G2.

[0074] The region on fluctuation pattern N1 shown by the dashed line in Figure 4, and the region located to the right of fluctuation pattern N1 in Figure 4, are clearly regions that should be judged as normal. In this embodiment, the normal judgment value G2 is the upward slope US1 of fluctuation pattern N1 (US1 = (SH2 - SH1) / (ST2(N) - ST1(N))).

[0075] If the control unit 3 responds "Yes" in step S117 shown in Figure 2, it proceeds to step S140 shown in Figure 3. The processing from step S140 onward will be described later.

[0076] On the other hand, if the control unit 3 determines "No" in step S117 shown in Figure 2, it proceeds to step S118. Then, the control unit 3 determines whether the timer is less than the first time T1.

[0077] As shown in Figure 4, in this embodiment, the first time T1 is preset to be later than the end time ST2(E) of the upward gradient measurement related to the variation pattern N1.

[0078] If the control unit 3 responds "No" in step S118 shown in Figure 2, it proceeds to step S140 shown in Figure 3. The processing from step S140 onward will be described later.

[0079] On the other hand, if the control unit 3 answers "Yes" in step S118 shown in Figure 2, it proceeds to step S119. The control unit 3 then determines that the supply air temperature has risen to the first state, which is the temperature at which the upward gradient measurement ends (an example of the "first temperature"), within the first time T1, and proceeds to step S120 shown in Figure 3.

[0080] In other words, the first state is a region located between the region that should be clearly judged as having an obstruction and the region that should be clearly judged as normal, and the fluctuation patterns J1 and J2 shown in Figure 4 are in that region.

[0081] When the control unit 3 moves from step S119 shown in Figure 2 to step S120 shown in Figure 3, it starts the second decision step.

[0082] Next, the control unit 3 proceeds to step S121, controls the fuel supply device 53, and changes the supply amount of fuel gas to a second flow rate FR2 that is less than the first flow rate FR1. The second flow rate FR2 is preset.

[0083] The second flow rate FR2 is set to a flow rate that is small enough for the intake air temperature to change from rising to falling, such as the fluctuation patterns J1 and J2 shown in FIG. 5. In this embodiment, the second flow rate FR2 is 50% or less of the first flow rate FR1.

[0084] Next, the control unit 3 executes steps S122 to S126. Steps S122 to S126 are processes for measuring the falling gradient DS1 of the intake air temperature.

[0085] As shown in FIG. 5, in this embodiment, the falling gradient measurement start temperature SH3 and the falling gradient measurement end temperature SH4 (<SH3) are preset. Also, in this embodiment, the falling gradient measurement start temperature SH3 is equal to the rising gradient measurement end temperature SH2. Note that the falling gradient measurement start temperature SH3 may be different from the rising gradient measurement end temperature SH2.

[0086] The falling gradient measurement start time ST3 when the intake air temperature drops to the falling gradient measurement start temperature SH3 and the falling gradient measurement end time ST4 when the intake air temperature drops to the falling gradient measurement end temperature SH4 change according to the blockage rate of the exhaust passage 76.

[0087] The difference between the falling gradient measurement end time ST4 and the falling gradient measurement start time ST3 (L3 and L4 shown as an example in FIG. 5) increases as the blockage rate of the exhaust passage 76 increases.

[0088] When the control unit 3 proceeds to step S122 shown in FIG. 3, it determines whether or not the intake air temperature has dropped to the falling gradient measurement start temperature SH3, and repeats step S122 until the result is "Yes".

[0089] Then, if the control unit 3 answers "Yes" in step S122, it proceeds to step S123 and stores the start time ST3 for measuring the downward gradient when the supply air temperature has dropped to the downward gradient measurement start temperature SH3.

[0090] Next, the control unit 3 proceeds to step S124, where it determines whether the supply air temperature has dropped to the downward gradient measurement end temperature SH4, and repeats step S124 until it determines "Yes".

[0091] Then, if the control unit 3 answers "Yes" in step S124, it proceeds to step S125 and stores the time ST4 when the downward gradient measurement is completed, which is when the supply air temperature has dropped to the downward gradient measurement completion temperature SH4.

[0092] Next, the control unit 3 proceeds to step S126 and calculates the downward slope DS1 of the supply air temperature. The downward slope DS1 is the value obtained by dividing the difference between the downward slope measurement end temperature SH4 and the downward slope measurement start temperature SH3 by the difference between the downward slope measurement end temperature SH4 and the downward slope measurement start temperature SH3 (DS1 = (SH4 - SH3) / (ST4 - ST3)). The downward slope DS1 is a negative value, and the value becomes closer to zero as the obstruction rate of the exhaust passage 76 increases.

[0093] Next, the control unit 3 proceeds to step S127 and determines whether the downward slope DS1 is greater than or equal to the abnormality determination value G3.

[0094] The region on the downward curve in the fluctuation pattern J1 shown in Figure 5, and the region located above that region, are areas that should be judged as having an obstruction abnormality. In this embodiment, the abnormality judgment value G3 is the downward slope DS1 of the range indicated by "L4" in the fluctuation pattern J1. (DS1=(SH4-SH3) / (ST4(E)-ST3(E))).

[0095] If the control unit 3 responds "No" in step S127 as shown in Figure 3, it proceeds to step S140. The processing from step S140 onward will be described later.

[0096] On the other hand, if the answer in step S127 is "Yes", the process proceeds to step S128.

[0097] When the system moves from step S116 shown in Figure 2, or from step S127 to step S128 shown in Figure 3, the control unit 3 determines that there is an obstruction abnormality.

[0098] Next, the control unit 3 proceeds to step S130, where it controls the display unit 3D to notify of the blockage abnormality. Step S130 is the notification step.

[0099] Next, the control unit 3 moves to step S131, where it controls the fuel supply device 53 to stop the supply of fuel gas and extinguish the burner 50. Step S131 is the stop step.

[0100] Next, the control unit 3 proceeds to step S131, and after confirming that the supply air temperature measured by the supply air temperature sensor S1 and the exhaust air temperature measured by the exhaust air temperature sensor (not shown) have decreased to a certain extent, it stops the motor 60, the drying drum 80 and the blower fan 78, and terminates this program. In this way, the control unit 3 abnormally terminates the drying operation.

[0101] Furthermore, as shown in Figure 4, the control unit 3 will also terminate the drying operation abnormally if the supply air temperature measured by the supply air temperature sensor S1 rises to the upper limit temperature Tmax, which is set in advance for safety reasons.

[0102] When the program transitions from step S117, step S118 shown in Figure 2, or from step S127 to step S140 shown in Figure 3, the control unit 3 determines that there is no blockage abnormality, terminates the program, and continues the drying operation.

[0103] <Effects and Effects> In the clothes dryer 1 of the embodiment, if the control unit 3 determines in the first determination steps S110 to S119 shown in Figure 2 that the first state is in place, that is, if it determines that the amount of increase in the supply air temperature is large, it does not immediately determine that there is an obstruction abnormality, but instead executes the second determination steps S120 to S128 shown in Figure 3.

[0104] Here, the control unit 3 takes advantage of the fact that when the blockage rate of the exhaust passage 76 increases, even a slight difference in the blockage rate results in a clear difference that causes the supply air temperature to decrease.

[0105] In other words, when the intake air temperature is rising and there is no clear difference indicating whether or not there is an obstruction, the control unit 3 lowers the intake air temperature in step S121 of the second judgment step by changing the fuel gas supply amount to a second flow rate FR2 which is less than the first flow rate FR1. Then, in steps S122 to S128, the control unit 3 determines whether or not there is an obstruction when there is a clear difference in the degree to which the intake air temperature decreases, for example, as shown in fluctuation patterns J1 and J2 in Figure 5.

[0106] As a result, the control unit 3 can prevent it from mistakenly determining that there is no blockage abnormality when there is, or from mistakenly determining that there is a blockage abnormality when there is no blockage abnormality.

[0107] Therefore, the clothes dryer 1 of the embodiment can reduce the frequency of abnormal shutdowns and improve user convenience.

[0108] Furthermore, this clothes dryer 1 can suppress damage to the clothes CL1 from high-temperature mixed gas by performing a second decision step S120-S128, which involves reducing the fuel gas supply from a first flow rate FR1 to a second flow rate FR2.

[0109] Furthermore, in this clothes dryer 1, the control unit 3 measures the upward gradient US1 of the supply air temperature in the first judgment steps S110 to S119 shown in Figure 2. If the upward gradient US1 is greater than or equal to the abnormality judgment value G1, it determines that there is a blockage abnormality and terminates the first judgment steps S110 to S119. As shown in Figure 3, it executes the notification step S130 and the stop step S131 without executing the second judgment steps S120 to S128. In this way, the control unit 3 can quickly execute the notification step S130 and the stop step S131 by determining that it is better not to continue combustion by the burner 50 when the supply air temperature rises excessively. As a result, this clothes dryer 1 can suppress malfunctions caused by blockage abnormalities.

[0110] Furthermore, in this clothes dryer 1, the control unit 3 measures the upward gradient US1 of the supply air temperature in the first judgment steps S110 to S119 shown in Figure 2. If the upward gradient US1 is less than or equal to the normal judgment value G2, it determines that there is no blockage abnormality and terminates the first judgment steps S110 to S119, and does not execute the second judgment steps S120 to S128 shown in Figure 3. This configuration prevents the reduction of the gas supply amount in the second judgment steps S120 to S128 even though there is no blockage abnormality, thus making it less likely for the drying time to become long.

[0111] Although the present invention has been described above with reference to examples, it goes without saying that the present invention is not limited to the above examples and can be applied with appropriate modifications without departing from its spirit.

[0112] In the embodiments, the drying apparatus of the present invention was embodied as a clothes dryer 1, but the present invention is not limited to this configuration. For example, the drying apparatus of the present invention may be an industrial drying apparatus for drying objects other than clothing, such as intermediate components in a manufacturing process.

[0113] In the embodiment, the control unit 3 executes notification step S130 and stop step S131 when it determines that there is an abnormal blockage, but the present invention is not limited to this configuration. For example, the present invention also includes configurations in which the control unit executes only the notification step or only the stop step.

[0114] In the embodiment, the supply air temperature sensor S1 is located near the communication hole 87A in the supply air passage 72, but the present invention is not limited to this configuration. For example, configurations in which the position of the supply air temperature sensor S1 in the embodiment is changed to be near the inlet 72A, or to an intermediate position between the communication hole 87A and the inlet 72A, are also included in the present invention.

[0115] In this embodiment, the control unit 3 determines whether or not there is an obstruction abnormality based on the downward slope DS1 in the second determination steps S120 to S128, but the present invention is not limited to this configuration. For example, the control unit may determine whether or not there is an obstruction abnormality based on the time required for the supply air temperature to drop to a threshold in the second determination step.

[0116] In the embodiment, the rising gradient measurement completion temperature SH2 is an example of the "first temperature" of the present invention, but the present invention is not limited to this configuration. For example, the first temperature may be set higher than the rising gradient measurement completion temperature SH2.

[0117] In the embodiment, the first time T1 is set to be later than the end time ST2(E) of the upward gradient measurement related to the variation pattern N1, but the present invention is not limited to this configuration. For example, the first time T1 may be set to be the same as the end time ST2(E) of the upward gradient measurement related to the variation pattern N1. [Industrial applicability]

[0118] The present invention can be used, for example, in drying devices such as clothes dryers. [Explanation of Symbols]

[0119] 1…Drying device (clothes dryer) 53…Fuel supply device 50... Burner CL1…Items to be dried (clothing) 81...Drying room 72... Air supply passage 78... Blower fan 76... Exhaust passage S1…Temperature measuring device (supply air temperature sensor) 3…Control Unit FR1…1st flow rate T1...1st hour SH2…First temperature (temperature at which the upward gradient measurement ends) S110~S119...First decision step FR2…Second flow rate S120~S128...Second decision step S130... Hochi Step S131... Stop step G1... Abnormality detection value G2...Normal detection value

Claims

1. A fuel supply device that supplies fuel gas, A burner that takes in air and burns the fuel gas supplied from the fuel supply device to generate a high-temperature mixed gas of combustion exhaust and air, A drying chamber for containing the material to be dried, An air supply passage that guides the mixed gas from the burner to the drying chamber, A blower fan that supplies the mixed gas to the drying chamber, An exhaust passage for discharging the mixed gas from the drying chamber, A temperature measuring device for measuring the supply air temperature of the mixed gas within the supply air passage, A control unit that controls the fuel supply device, the burner, and the blower fan, and acquires the supply air temperature measured by the temperature measuring device, Equipped with, The control unit starts combustion by the burner with the fuel gas supply amount set to a first flow rate, and then performs a first determination step to determine whether or not the supply air temperature is in a first state where it rises to a first temperature in less than a first hour. If the control unit determines that the first state is present, it changes the supply amount to a second flow rate which is less than the first flow rate, and performs a second determination step to determine whether or not there is an abnormal blockage in the discharge of the mixed gas from the drying chamber, based on the degree to which the supply air temperature decreases. The drying apparatus is characterized in that, when the control unit determines that there is an abnormal blockage, it performs at least one of the following: a notification step of notifying the abnormal blockage, and a stop step of stopping the fuel supply device and the burner.

2. The drying apparatus according to claim 1, wherein the control unit measures the upward gradient of the supply air temperature in the first determination step, and if the upward gradient is greater than or equal to an abnormality determination value, it determines that there is an abnormal blockage and terminates the first determination step, and without executing the second determination step, executes at least one of the notification step and the stop step.

3. The drying apparatus according to claim 1 or 2, wherein the control unit measures the upward gradient of the supply air temperature in the first determination step, and if the upward gradient is less than or equal to the normal determination value, it determines that there is no blockage abnormality and terminates the first determination step, and does not perform the second determination step.

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