JP3962739B2 - Operation method of hot air storage - Google Patents

Description

  The present invention relates to a method for operating a hot-air storage, and more specifically, hot air is forcibly circulated in a storage unit disposed with a required space interposed in a heat insulating box to heat the tableware stored in the storage unit. The present invention relates to a method of operating a hot-air storage that performs disinfection and drying.

  The hot-air storage that disinfects and dries by applying hot air to the tableware is heated inside the heat insulation box, with a storage section through the required space, on a shelf arranged in multiple stages in the storage section, A basket containing tableware is placed. The space includes an upper space defined at the top of the top plate of the storage unit, a side space defined outside the side plates facing the width direction of the storage unit, and a blower outlet formed at the lower end of the side space. And a bottom space communicating with each other. The top plate is formed with a suction port communicating with the upper space, and a blower and a heater are disposed in the upper space.

  In the hot-air storage, by operating the blower, the air in the storage section sucked into the upper space through the suction port is heated by exchanging heat with the heater, and then the obtained hot air is caused to flow down to both side spaces. . Then, hot air blown out from the outlet of each side space into the bottom space is introduced into the storage portion and raised, and forcedly circulated back to the upper space from the suction port, whereby the tableware stored in the storage portion It is configured to disinfect and dry by heating.

  As described above, in the hot air storage where the hot air is forcibly circulated to disinfect and dry the tableware, to the blowing side of the air (hot air) heated by the heater, or to the heater of the air whose temperature has been lowered by heat exchange with the tableware A temperature sensor is arranged on either of the suction sides of the storage unit, and during the preset time, the heater is turned on and off based on the detected temperature detected by the temperature sensor, thereby the inside of the storage unit A heat-retaining operation is performed to keep the temperature at a preset temperature.

  In the hot-air storage, as described above, separately from the heat insulation operation control for keeping the inside of the storage unit at a set temperature, the protection operation control for stopping the operation of the storage when the temperature in the storage part exceeds a preset abnormal temperature. Is done. However, since any operation control is performed by detecting the temperature, for example, when the heater is disconnected or the storage door is open, the detected temperature does not rise easily, or the temperature detection unit (temperature sensor etc. When the temperature lower than the actual temperature is detected due to the failure of), the protection operation control does not work, and there is a problem that the operation is continued in a state where the sterilization and drying of the tableware cannot be sufficiently performed. In addition, in this case, since the heater is continuously energized (continuous ON state), it is pointed out that the heater deteriorates in a short period of time.

  The hot-air storage is provided with an operation panel that displays the actual temperature, set temperature, or set time in the storage unit. Conventionally, the temperature and time are displayed on the same display unit, and the operator Switches the display of temperature and time by operating the switch button. In other words, the operator needs to operate the switch button to grasp the operating status of the storage, and when changing the set temperature, operating time, etc., it is necessary to check what is currently displayed. For this reason, the work is complicated.

  The present invention has been proposed in view of the above-described problems inherent in the prior art described above, and has been proposed to suitably solve this problem. Hot air that can improve safety by detecting abnormal situations such as failures. An object is to provide a method of operating a formula storage.

In order to overcome the above-described problems and achieve the desired purpose suitably, the operation method of the hot-air storage according to the present invention is as follows.
An interior fan and the heater of the box, by forced circulation of heated air by the heater and the heat exchanger by the operation of the air blowing device, ON-OFF with a pre-Symbol heater for heating the dishes housed in the interior In a hot-air storage that controls and keeps the inside of the box at a set temperature,
The operation is stopped when the continuous energization time of the heater exceeds a preset abnormal continuation time.

In the operation method of the hot-air storage according to the present invention, the occurrence of an abnormal situation is detected by the continuous energization time of the heater and the operation is stopped, so that the safety of the hot-air storage is improved and the heater Unnecessary continuous operation can be prevented and the life of the heater can be extended. In addition, since the temperature and time are independently displayed separately on the operation panel, the operator can grasp the operation status of the hot-air storage without operating the switching button or the like.

  Next, the operation method of the hot-air storage according to the present invention will be described below with reference to the accompanying drawings by giving a preferred embodiment.

  FIG. 1 is a schematic view showing a hot-air storage according to an embodiment. The hot-air storage 10 includes a heat insulating box (box) 12 having a heat insulating structure in which glass wool is filled between an exterior and an interior. A storage portion 16 is arranged inside the inner wall and the required space 14 while being held. The storage portion 16 has a suction port 18 a formed at the center of the top plate 18. In addition, a plurality of shelves 20 are arranged in a plurality of stages at predetermined intervals in the vertical direction inside the storage unit 16, and a basket 22 that stores tableware (not shown) is placed on each shelf 20. It has become.

  The space 14 is defined as an upper space 14a defined in the upper part of the top plate of the storage unit 16 and a side which is defined outside the side plates 24 and 24 facing the width direction of the storage unit 16 and communicates with the upper space 14a. The space 14b, 14b and the bottom space 14c defined in the heat insulation box 12 and facing the lower side of the storage portion 16, and the bottom space 14c is formed at the lower end of the side spaces 14b, 14b. 26 and 26. The storage portion 16 communicates with the upper space 14a through the suction port 18a, communicates with the bottom space 14c, and further through a plurality of through holes (not shown) formed in the side plates 24 and 24. It communicates with the partial spaces 14b and 14b.

  A blower 28 is disposed in the upper space 14a, and a heater 30 is disposed in the upper space 14a adjacent to the blower 28. The blower 28 is set so as to suck the air in the storage portion into the upper space 14 a from the suction port 18 a of the storage portion 16 and blow the air toward the heater 30. Therefore, by operating the blower 28, the air sucked from the storage unit 16 side is heated by being brought into contact with the heater 30 to be hot air, and then flows into the both side spaces 14b and 14b. And this hot air is blown in in the accommodating part 16 from the through-hole of the said blower outlets 26 and 26 and the side plate 24, and it is comprised so that the tableware accommodated may be heated.

A first temperature sensor 32 is disposed in the vicinity of the suction port 18 a that is the suction side of the air that heated the tableware to the heater 30, and one of the blowout ports 26 that is the discharge side of the heated air from the heater 30. A second temperature sensor 34 is disposed in the vicinity (side space 14b), and based on the detected temperatures (suction side temperature, blowout side temperature) detected by both temperature sensors 32, 34, a control device (not shown) It is configured to perform control (energization control) for turning on and off the power to the heater 30. That is, the condition that the suction-side temperature detected by the first temperature sensor 32 exceeds the preset temperature T and the blow-out temperature detected by the second temperature sensor 34 is a predetermined temperature α from the preset temperature T. When _{one of} the conditions exceeding the upper limit set temperature T ₁ (= T + α), which is higher by (for example, 10 ° C.), is satisfied, the heater 30 is turned off (energization is stopped), and the first temperature sensor 32 When both the condition that the detected suction side temperature is lower than the set temperature T and the condition that the blowout temperature detected by the second temperature sensor 34 is lower than the upper limit set temperature T ₁ are satisfied, The heater 30 is set to be ON-controlled (energized). And the center temperature in a storage part is hold | maintained at the setting temperature T by carrying out ON-OFF control of the heater 30 in this way (refer FIG. 4). The upper limit set temperature T ₁ is set in a range in which the central temperature in the storage unit does not become higher than the set temperature T in the initial operation of the hot-air storage 10 described later.

  As shown in FIG. 2, the heat insulation box 12 is provided with double door heat insulation doors (doors) 36 and 36 for closing and opening the opening 12a. A magnet 38 is disposed at a predetermined position of one heat insulating door 36, and a reed switch 40 is provided on the box side corresponding to the magnet 38, so that the open / closed state of the door 36 can be detected. In the embodiment, the control device is set to perform the ON / OFF control of the heater 30 and the blower 28 based on the ON / OFF operation of the reed switch 40 as the detecting means. That is, when the magnet 38 is close to the reed switch 40 and the switch 40 is turned on by closing the heat insulating door 36, the heater 30 and the blower 28 are controlled to be ON, and the heat insulating door 36 is opened. Thus, when the magnet 38 is separated from the reed switch 40 and the switch 40 is turned off, the heater 30 and the blower 28 are turned on. In the embodiment, the other heat insulating door 36 on which the magnet 38 is not disposed is configured to be openable by opening the one heat insulating door 36.

  A cabinet 44 surrounding the motor 42 and the like of the blower 28 is disposed on the heat insulating box 12, and an operation panel 46 having operation switches and the like is disposed on the front surface of the cabinet 44. . The operation panel 46 is for performing an operation such as setting tableware heating conditions (set temperature, set time, etc.). As shown in FIG. 3, the operation switch 48, a temperature display unit 50, and a time display unit 52 are used. A temperature setting button 54, temperature change buttons 56, 56, a time setting button 58, time change buttons 60, 60, and the like are provided. The operation switch 48 is for starting an operation (heating operation) for heating the tableware by the hot-air storage 10, and by turning on the switch 48, the two temperature sensors 32, 34 described above are operated. A heat retention operation is performed in which the central temperature in the storage unit is maintained at the set temperature T based on the detected temperature.

  The temperature display unit 50 displays not only the set temperature T and the central temperature in the storage unit (the temperature detected by the first temperature sensor 32 or the second temperature sensor 34), but also status displays corresponding to various states. Is set to perform. As this status display, for example, a display indicating that the operation has been interrupted due to a power failure (FAL), a display indicating the delayed operation (AS), a display indicating that the heat insulation door 36 is open (dor), and the operation is completed. There is a display (End) or the like indicating that the The temperature display unit 50 always displays the value of the first temperature sensor 32, displays the set temperature T when the temperature setting button 54 is pressed, and operates the temperature change buttons 56 and 56 in this display state. By doing so, the set temperature T can be arbitrarily changed. In addition, when it will be in each said state in the hot-air storage 10, the said status display and temperature display are displayed alternately by several second intervals (for example, 1 second).

  The time display unit 52 displays a set time for heating the tableware at the set temperature T and the remaining time, and also displays an error display (Er1, Er2,...) Corresponding to various abnormal situations. Is set. The set time is counted by a counter (not shown) from the time when the central temperature in the storage section first reaches the set temperature T after the heating operation of the tableware is started (when the operation switch 48 is turned ON). Yes. The time display unit 52 always displays the set time and displays the remaining time after the counter starts counting. Note that when various abnormal situations occur, the error display and the time display are alternately displayed at intervals of several seconds (for example, 1 second).

  In the hot air storage 10, the abnormal operation control is performed to detect an abnormal situation and stop the operation. That is, an abnormal temperature sensor (not shown) (which can also be used as the first or second temperature sensor) is configured to stop the operation of the storage 10 when it detects a preset abnormal temperature. Further, when the continuous energization time (continuous ON time) of the heater 30 exceeds a preset abnormal continuation time, the operation of the storage 10 is set to be stopped. Here, in the initial operation from the start of the heating operation of the tableware until it reaches the set temperature T, it takes a long time for the central temperature in the storage section to reach the set temperature T. Therefore, the heater 30 continues during the initial operation. The first abnormality continuation time for determining occurrence of abnormality with respect to the energization time is set to be relatively long (for example, 2 hours). Further, in the heat insulation operation, the time required for the central temperature in the storage section to reach the set temperature T again after once decreasing from the set temperature T is short, so there is an abnormality in the continuous energization time of the heater 30 during the heat insulation operation. The second abnormality continuation time for determining occurrence is set to be relatively short (for example, 20 minutes).

  When the set temperature T is changed to a high temperature side during the heat insulation operation or when the heat insulating door 36 is opened, an abnormal continuation time serving as a reference for determining occurrence of an abnormality with respect to the continuous energization time of the heater 30 Is set to be changed from the second abnormal duration to the first abnormal duration. Further, when the occurrence of abnormality is detected based on the continuous energization time of the heater 30 and the operation of the hot-air storage 10 is stopped, the error display is displayed on the time display unit 52.

  In the hot-air storage 10, when one of the first temperature sensor 32 and the second temperature sensor 34 is stopped due to a failure or the like, the other temperature sensor that operates normally without stopping operation immediately. Based on the detected temperature, the heater 30 is controlled to be turned on and off to continue the operation. Further, at this time, an error is displayed on the time display unit 52, and when the heating operation for that time is completed, the next heating operation cannot be started, so that an abnormal situation is dealt with. Further, when both the temperature sensors 32 and 34 are stopped due to a failure or the like, the operation is set to stop immediately. In addition, the following table | surface shows the relationship of the operation | movement according to the state of the temperature sensors 32 and 34, the presence or absence of an error display, etc.

┏━━━━━┳━━━━━┳━━━━━━━━━━━━┳━━━━━━━┓
┃ First temperature ┃ Second temperature 運 転 Start operation 開始 Operation at that time ┃ Error display ┃
セ ン サ Sensor ┃ Sensor ┃ ┃ ┃ ┃
┣━━━━━╋━━━━━╋━━━━━━━━━━━━╋━━━━━━━┫
┃ Normal ┃ Normal ┃ Possible 継 続 Continue ┃ No ┃
┣━━━━━╋━━━━━╋━━━━━━━━━━━━╋━━━━━━━┫
┃ Normal ┃ Failure ┃ Impossible ┃ Continue ┃ Yes ┃
┣━━━━━╋━━━━━╋━━━━━━━━━━━━╋━━━━━━━┫
故障 Failure ┃ Normal ┃ Impossible ┃ Continue ┃ Yes ┃
┣━━━━━╋━━━━━╋━━━━━━━━━━━━╋━━━━━━━┫
┃ Failure ┃ Failure ┃ Impossible 停止 Stop ┃ Yes ┃
┗━━━━━┻━━━━━┻━━━━━━━━━━━━┻━━━━━━━┛

  In the hot-air storage 10, the exhaust duct (not shown) is opened when a predetermined time has elapsed after the count of the set time T is started, and the temperature sensors 32, 34 are set immediately before the operation is completed. Regardless of the detected temperature, the heater 30 is OFF-controlled, and the blower 28 cools down the heater 30 and the heater periphery.

(Effects of Example)
Next, the operation of the hot-air storage according to the embodiment configured as described above will be described in relation to the operation method.

  Before explaining the operation of the embodiment, the temperature provided on either the blow side of the air (hot air) heated by the heater or the suction side of the air whose temperature has been reduced by heat exchange with the tableware A conventional problem of ON-OFF control of the heater based on the detected temperature detected by the sensor will be briefly described.

  The temperature detected by the temperature sensor arranged on the blow-out side or the suction side is different from the central temperature in the storage section, and when the heater is controlled at the blow-out side temperature, the rise in the storage section temperature is delayed. There is. That is, if the heater is turned on and off so that the blowout side temperature becomes the set temperature, the central temperature in the storage portion is lower than the blowout side temperature in the initial stage of operation, so the temperature sensor detects the set temperature and the heater is turned off. Even when the center temperature has not reached the set temperature. And if the tableware in a storage part heats and the hot air which blown off will not be cooled by tableware, the temperature difference of the blowing side and the center part in a storage part will become small. However, as shown in FIG. 5 (a), the temperature difference gradually decreases, and it takes a long time until the central portion in the storage portion is finally held at the set temperature.

  Moreover, when controlling the said heater by suction side temperature, since the center temperature in a storage part becomes high and the blowing side temperature becomes still higher, there exists a possibility of deteriorating tableware. That is, if the heater is turned on and off so that the suction side temperature becomes the set temperature, the central temperature in the storage unit is higher than the suction side temperature in the initial stage of operation. The set temperature is not detected and the heater is turned on. And when the tableware in a storage part heats and the hot air which blows off is no longer cooled by tableware, the temperature difference of the suction side and the center part in a storage part will become small gradually. However, as shown in FIG. 5 (b), before the central portion in the storage portion is finally held at the set temperature, the central temperature becomes considerably higher than the set temperature, and the blowout side temperature is even higher than the central temperature. In particular, the tableware stored in the vicinity of the blowout side may be exposed to high temperatures and deteriorate.

  To explain in order from the start of the operation of the hot-air storage 10 according to the embodiment, the temperature change button 56, 56 is operated to display and set a desired set temperature T. Similarly, when the set time is displayed on the time display unit 52 by pressing the time setting button 58, the time setting buttons 60 and 60 are operated to display and set the desired set time. In this case, the set temperature T and the set time are separately displayed separately and are changed by the separate change buttons 56 and 60, so that the operator can be prevented from changing the temperature and time by mistake. Is done.

  Next, when the operation switch 48 is turned ON, the operation of the blower 28 is started and energization to the heater 30 is started, and the air in the storage unit 16 is moved upward by the blower 28 through the suction port 18a. The air is sucked into the space 14a and blown toward the heater 30, where it is heated by heat exchange to become hot air and then flows into the side spaces 14b and 14b. The hot air flowing into each side space 14b is blown into the storage portion from the outlet 26 and the through hole, and heats the stored tableware. Then, the air whose temperature has decreased due to heat exchange with the tableware is circulated so as to be sucked into the upper space 14a again through the suction port 18a (see FIG. 1).

The heater 30 is ON / OFF controlled based on the detected temperatures of the first temperature sensor 32 and the second temperature sensor 34, and the central temperature in the storage section is held at the set temperature T. In this case, since the tableware is cold at the initial operation, there is a large difference between the blowout side temperature detected by the second temperature sensor 34 and the central temperature in the storage section, and the blowout side temperature is set as in the conventional case. When the heater 30 is turned off when the temperature T is reached, it takes a long time for the central temperature in the storage section to reach the set temperature T as described above. However, in the hot-air storage 10 of the embodiment, the condition that the suction side temperature detected by the first temperature sensor 32 exceeds the set temperature T and the blowout side temperature detected by the second temperature sensor 34 are the upper limit set temperature. When any one of the conditions exceeding T ₁ is satisfied, the heater 30 is controlled to be OFF. That is, the heater 30 can be turned on until the second temperature sensor 34 detects the upper limit set temperature T ₁ that is higher than the set temperature T by the predetermined temperature α, so that the central temperature in the storage section reaches the set temperature T in the initial operation. Can be shortened (see FIG. 4). Moreover, since the upper limit set temperature T ₁ is set to a value at which the central temperature in the storage section does not rise above the set temperature T, it is prevented that the tableware is deteriorated by being exposed to high temperatures. Furthermore, after the central temperature in the storage section reaches the set temperature T, the heater 30 is controlled to be OFF by the first temperature sensor 34 that detects the suction side temperature detecting the set temperature T. Does not rise to the upper limit set temperature T ₁ .

  Further, during the above-described tableware heating operation, the operation panel 46 displays the central temperature in the storage unit and the set time or the remaining time at the same time, so that the operator can grasp the operation status without operating the switch button or the like. be able to. In addition, when each of the above states occurs or an abnormal situation occurs in the hot-air storage 10, the state display or error display is alternately displayed on the temperature display unit 50 or the time display unit 52 with the temperature display or the time display. Is displayed on the screen and can be noticed by the operator, so that the operator can quickly take action according to the situation.

(Operations associated with opening and closing of insulated doors)
In the hot-air storage 10, the ON / OFF control of the blower 28 and the heater 30 is performed according to the open / closed state of the heat insulating door 36 detected by the reed switch 40, so each case will be described.

  (1) When the heat insulating door 36 is opened at the start of operation (after the operation switch 48 is turned ON), the blower 28 and the heater 30 are not controlled to be turned on, and the tableware heating operation is not started. Then, on the condition that the reed switch 40 detects that the heat insulating door 36 is closed, the blower 28 and the heater 30 are controlled to be ON and the heating operation is started.

  (2) When the reed switch 40 detects that the heat insulating door 36 has been opened during the initial operation before the central temperature in the storage section reaches the set temperature T, the blower 28 and the heater 30 are controlled to be OFF. Then, the heating operation is restarted on the condition that the reed switch 40 detects that the heat insulating door 36 is closed.

  (3) If the reed switch 40 detects that the heat insulation door 36 is opened before the exhaust duct is opened during the heat insulation operation after the central temperature in the storage section reaches the set temperature T, the blower 28 and the heater 30 are detected. Is controlled OFF. At this time, the count of the set time is also stopped, but it is possible to select whether to hold the stopped value or to perform the count from the beginning after the central temperature in the storage portion reaches the set temperature T again after resetting and restarting the operation. . Then, on the condition that the reed switch 40 detects that the heat insulating door 36 is closed, the heating operation is restarted, and when the count value is held, the count is restarted from that value.

  (4) When the reed switch 40 detects that the heat insulation door 36 is opened after the exhaust duct is opened, the blower 28 and the heater 30 are controlled to be OFF, and the exhaust duct is also closed. At this time, the counting of the set time T is also stopped, but it is selected whether to hold the stopped value or to start counting after the central temperature in the storage section reaches the set temperature T again after resetting and restarting the operation. it can. Then, on the condition that the reed switch 40 detects that the heat insulating door 36 is closed, the heating operation is restarted, and when the count value is held, the count is restarted from that value, and the exhaust duct. Is released.

  (5) When the reed switch 40 detects that the heat insulating door 36 has been opened during the cool-down, the blower 28 is controlled to be OFF and the exhaust duct is also closed. In this case, even if the reed switch 40 detects that the heat insulating door 36 is closed again, the cool-down is not resumed.

  In addition, when the heat insulation door 36 is opened in the above (1) to (5), the temperature display section 50 displays that the heat insulation door 36 is opened and notifies the operator. Further, the ON control timing of the blower 28 and the heater 30 and the opening timing of the exhaust duct performed by closing the heat insulating door 36 are set after a slight delay after the heat insulating door 36 is closed. At this time, adverse effects on the motor and the like due to chattering of the reed switch 40 are prevented.

  As described above, when the heat insulating door 36 is opened during operation, the operation of the blower 28 is stopped, so that hot air can be prevented from being blown out from the opening 12a. When the heating operation is performed with the heat insulating door 36 opened, the heater 30 for increasing the central temperature in the storage section to the set temperature T becomes longer and consumes a lot of power, but the heat insulating door 36 is opened and closed. In this case, since both the blower 28 and the heater 30 are in the OFF state while the door 36 is open, useless heating is not performed and the power consumption can be reduced. Furthermore, since it is displayed on the temperature display unit 50 that the heat insulating door 36 is in an open state, for example, in a hot air storage cabinet of a type in which the heat insulating doors are arranged before and after the heat insulating box 12, Even if it cannot be confirmed that the heat insulation door is open, the tableware can be surely sterilized and dried without overlooking that the heat insulation door is open.

(Driving when an abnormal situation occurs)
Next, when one of the first temperature sensor 32 and the second temperature sensor 34 is stopped due to a failure during the heat insulation operation in which the central temperature in the storage unit is maintained at the set temperature T (the temperature is no longer detected). In the case), the ON / OFF control of the heater 30 is continuously performed based on the temperature detected by the other temperature sensors 34 and 32 that operate normally, and the corresponding error display is made on the time display unit 52. . Thereby, it is possible to prevent the tableware from being left without being disinfected and dried, and to make the operator aware of the failure. In addition, when one of the temperature sensors 32 and 34 is continued in the state of failure, the next operation cannot be started, so the operator overlooks the error display and operates. Even if it tries to make it, it cannot drive | operates and can know reliably that the failure has generate | occur | produced. If both the temperature sensors 32 and 34 fail to detect the temperature, the operation can be immediately stopped and an error can be displayed to notify the operator of the occurrence of the failure.

  During operation of the hot-air storage 10, when the central temperature inside the storage part rises greatly beyond the set temperature T for some reason and the abnormal temperature sensor detects an abnormal temperature, the operation of the hot-air storage 10 is performed. Is stopped and an appropriate error is displayed on the time display unit 52.

  Here, in the method of detecting an abnormal situation only based on a change in temperature, for example, when a failure (disconnection, etc.) occurs in the heater 30, an abnormality occurs in the temperature sensors 32 and 34 and the temperature is lower than the actual temperature. Abnormality in which the central temperature in the storage section does not reach the set temperature T, such as when the temperature is detected or when airtight leakage occurs due to an abnormality in the packing (not shown) provided in the heat insulating door 36 The occurrence of a situation cannot be detected. Therefore, in the embodiment, it is set so as to detect an abnormal situation also in accordance with the change in the continuous energization time of the heater 30 in addition to the detection by the change in temperature.

  That is, when the continuous energization time of the heater 30 exceeds the first abnormal continuation time during the initial operation from the start of the tableware heating operation until the set temperature T is reached, it is assumed that an abnormal situation has occurred and the hot air type The operation of the storage 10 is stopped and an error is displayed on the time display unit 52. Further, if the continuous energization time of the heater 30 exceeds the second abnormal continuation time during the heat insulation operation, it is assumed that an abnormal situation has occurred and the operation of the hot air storage 10 is stopped and the time display unit 52 Displays an error. Thereby, it is possible to detect the occurrence of an abnormal situation of the type described above that could not be detected only by a change in temperature, and the safety of the hot-air storage 10 is improved. Furthermore, since the heater 30 can be prevented from being continuously operated more than necessary, the life of the heater 30 can be extended.

  In addition, when the set temperature T is changed to a high temperature side during the heat insulation operation or when the heat insulating door 36 is opened, until the central temperature in the storage unit reaches the new set temperature T or the continuous set temperature T again. Since time is required, it is assumed that an abnormal situation has occurred when the continuous energization time of the heater 30 exceeds the first abnormal duration time, and the operation of the hot-air storage 10 is stopped and an error is displayed on the time display unit 52. Is done.

It is a vertical front view which shows schematic structure of the hot-air storage which concerns on the suitable Example of this invention. It is a principal part front view of the hot-air storage which concerns on an Example. It is a front view which shows the display panel of the hot-air storage which concerns on an Example. It is a graph which shows the relationship with the blowing side temperature, suction side temperature, and storage part center temperature of the hot-air storage which concerns on an Example. It is a graph which shows the relationship between the blowing side temperature which concerns on a prior art, and the center temperature in a storage part, and the suction side temperature and the center temperature in a storage part, respectively.

Explanation of symbols

12 Heat insulation box (box), 28 Blower, 30 heater, 36 Heat insulation door (door), 46 Control panel T Set temperature

Claims (5)

The box (12) is provided with a blower (28) and a heater (30), and the air heated by exchanging heat with the heater (30) by operating the blower (28) is forced to circulate inside. In the hot-air storage where the stored tableware is heated and the heater (30) is ON-OFF controlled to keep the inside of the box at a set temperature .
An operation method for a hot-air storage, wherein the operation is stopped when a continuous energization time of the heater (30) exceeds a preset abnormal continuation time. The heating operation start of the dishes, the first abnormality duration for continuous energization time of the heater (30) during the initial operation to reach a preset temperature (T), and once reached the set temperature (T) The operation method of the hot-air storage according to claim 1, which is set to be longer than the second abnormal continuation time with respect to the continuous energization time of the heater (30) during the heat-retaining operation to be held at the set temperature (T) later. When said set during maintenance operation temperature (T) was changed to the high temperature side, the abnormality duration to determine the continuous energization time to the pair to abnormality of the heater (30), first from the second abnormality duration The operation method of the hot-air storage according to claim 2, wherein the operation time is changed to an abnormal duration . During the maintenance operation, when opening the door (36) provided on the box body (12), the abnormality duration to determine the continuous energization time to the pair to abnormality of the heater (30), second The operation method of the hot-air storage according to claim 2 , wherein the abnormality duration is changed to the first abnormality duration . The operation method of the hot-air storage according to any one of claims 1 to 4, wherein the temperature and time are independently and separately displayed on the operation panel (46) provided in the box (12). .

Images