JP6660796B2 - Flyer - Google Patents

Description

  The present invention relates to a fryer for cooking food by heating cooking oil stored in an oil tank.

For example, the pressure fryer has an oil tank that can be opened on the upper surface and stores cooking oil, a heating means such as a pulse combustor that heats the cooking oil in the oil tank, and a lid that can open and close the opening of the oil tank, By heating the cooking oil with a heating means in a state where the oil tank is closed by the lid, it is possible to cook food under pressure (for example, see Patent Document 1).
Such a pressure fryer is installed in a kitchen such as a restaurant or a fast food store. When a main power button on an operation panel provided on the front is turned on, the heating means is operated to solidify cooking oil in the oil tank. A standby temperature (for example, 120 ° C.) sufficient for liquefying the oil and lower than the cooking temperature is maintained. Thus, when cooking is performed using the selected cooking menu, the cooking oil can be quickly heated to the set cooking temperature and the food can be heated and cooked.

JP 2011-244942 A

In such a pressure fryer, when the oil tank is closed by the lid, the state of the oil tank is difficult to understand. For this reason, for example, there is a risk that the user may press the main power button without opening and checking the lid, even though the water is in the state after the oil tank has been washed. In this case, cooking cannot be performed just by turning the water into hot water, so that it takes time to discharge water and store cooking oil again, resulting in a large loss of time before the start of cooking.
On the other hand, if a new configuration is added for judging oil / water in the oil tank, the cost is increased, and the use in a severe environment may cause an increase in failures.

  Therefore, the present invention provides a fryer that can detect whether cooking oil or water is being charged in an oil tank using an existing configuration without adding a new configuration, without loss of time. It was intended.

Means for Solving the Problems To achieve the above object, an invention according to claim 1 includes an oil tank that stores cooking oil, heating means for heating the cooking oil in the oil tank, temperature detection means for detecting the temperature of the cooking oil, and heating. A controller that controls the means and performs oil / water determination control to determine whether the liquid in the oil tank is cooking oil or water based on the temperature detected from the temperature detection means,
When water is contained in the oil tank and heated by the heating means, the controller increases the detected temperature from a predetermined first temperature in a temperature zone lower than the boiling temperature of water to a second temperature higher than the boiling temperature. In the oil-water determination control, the controller operates the heating means until the detected temperature reaches the second temperature from the first temperature. When the temperature reaches the second temperature from the first temperature within the determination reference time, while determining the liquid in the oil tank as cooking oil,
If the detected temperature does not reach the second temperature from the first temperature within the determination reference time, the heating by the heating means is continued, and the detected temperature is set within a predetermined time after reaching the second temperature. When the temperature reaches a third temperature higher than the second temperature, the liquid in the oil tank is determined to be cooking oil, and when the detected temperature does not reach the third temperature within a predetermined time, The liquid in the oil tank is determined to be water.
According to a second aspect of the present invention, in the configuration of the first aspect, the second temperature is a temperature lower than the boiling temperature of water, the third temperature is a temperature higher than the boiling temperature, and the heating is performed within a predetermined time. Is performed at a lower capacity than the heating from the first temperature to the second temperature.
According to a third aspect of the present invention, in the configuration of the first or second aspect, the minimum time is the amount of water when water is contained in the oil tank, the gas input and the gas supply when the heating means is a pulse combustor. By changing one or more parameters among the pressure, the gas type, and the ambient temperature of the installation location of the oil tank, each time required for the detected temperature to rise from the first temperature to the second temperature is verified in advance. , Which is the shortest time among the verified times.

According to the first aspect of the present invention, it is determined whether or not the detected temperature rises from the first temperature to the second temperature within a determination reference time shorter than the shortest time assumed when the oil tank is filled with water. The determination of the oil and water is performed, so that if the temperature reaches the second temperature within the determination reference time, it can be determined that the oil is cooking oil, and the subsequent determination of the oil and water is unnecessary, and time wasted can be reduced. . Further, even if it is not determined that the cooking oil is the cooking oil in the first determination, the oil-water determination is performed by monitoring the arrival at the third temperature within a predetermined time thereafter, so that a more reliable determination can be made.
According to the second aspect of the invention, in addition to the effect of the first aspect, the oil / water determination is performed at the second and third temperatures set at the boiling temperature of water, so that cooking is performed in the first determination. Except for the case where oil is determined, oil can be reliably determined to be cooking oil or water. Further, since the capacity of the heating means is limited, boiling can be prevented even if water is charged in the oil tank.
According to the third aspect of the invention, in addition to the effect of the first or second aspect, the determination reference time is set from the shortest time verified in advance, so that the determination reference time for reliably determining the oil and water is set. It becomes possible.

It is a perspective view of a pressure fryer. It is a top view of a pressure fryer. It is a center longitudinal cross-sectional view of a pressure fryer (a lid main body is an upper limit position). FIG. 4 is an explanatory diagram showing a positional relationship between an oil level and first and second temperature sensors. It is a flowchart of oil-water determination control and heat retention / temperature control. It is a graph which shows the temperature change of oil and water by heating.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 are explanatory views showing a pressure fryer which is an example of a fryer. FIG. 1 is a perspective view, FIG. 2 is a plan view, and FIG. 3 is a central longitudinal sectional view. The pressure fryer 1 has a plan view at the center of a rectangular box-shaped housing 2 composed of a frame 3 serving as a framework and a panel (not shown) stretched outside the frame 3 (only the upper panel 4 is shown in FIG. 2). A rectangular oil tank 5 is installed with its upper end opening 6 projecting upward from the upper panel 4 so that the cooking oil contained in the oil tank 5 can be heated by a pulse combustor 7 as a heating means. It is. The upper panel 4 is provided with a lid 8 that can open and close the opening 6 of the oil tank 5. 9, 9,... Are casters provided at four corners on the lower surface of the housing 2.

  The pulse combustor 7 is provided on the inner surface on the front side of the oil tank 5 and burns a mixed gas of fuel gas and combustion air, and the combustion exhaust gas from the combustion chamber 10 is discharged to the inner surface of the oil tank 5. And a tail pipe 11 that circulates along it. The combustion chamber 10 is connected to a mixing chamber 13 in an air chamber 12 provided on the front outer surface of the oil tank 5. The mixing chamber 13 is connected to a combustion air from a fan 14 in the housing 2 via a pipe. Is supplied, and fuel gas is supplied from a gas conduit 16 provided with a blinker 15 having a solenoid valve.

  The downstream side of the tail pipe 11 is connected to left and right exhaust pipes 17 via an air chamber 12, and further guided into a rising portion 19 installed behind the housing 2 via a decoupler 18 and the like, so as to emit combustion exhaust gas. Can be discharged from the exhaust pipe 20. The rising portion 19 and the upper part of the oil tank 5 are connected by two steam discharge pipes 21 and 22. One of the steam discharge pipes 21 is provided with a constant pressure valve 23 and the pressure in the oil tank 5 during cooking is equal to or higher than a predetermined value. When the pressure increases, the pressure in the oil tank 5 is kept constant by releasing the pressure into the rising portion 19. The other steam discharge pipe 22 is provided with an opening valve 24 and releases the pressure in the oil tank 5 to the rising portion 19 by opening the opening valve 24 immediately before the end of the cooking, thereby reducing the pressure in the oil tank 5 to normal pressure. Lower. The rising section 19 has an oil separator for separating oil and the like from the steam introduced therein, and discharges the steam from which the oil has been separated from the exhaust port 25 on the upper surface.

On the other hand, an oil tank 27 connected to the bottom of the oil tank 5 by an oil drain pipe 26 is provided below the oil tank 5 in the housing 2, and the cooking oil filtered by a filter 28 provided in the oil tank 27 is returned by a pump 29. By returning the oil into the oil tank 5 via the pipe 30, the filtering of the cooking oil is possible.
Reference numeral 31 denotes a burner controller provided on the lower side of the side surface of the housing 2. The burner controller 31 is connected to an electromagnetic valve of the blinker 15 and a first temperature sensor 34 provided in the oil tank 5. 1 Based on the temperature detection signal from the temperature sensor 34, the electromagnetic valve of the blinker 15 is opened and closed so that the oil temperature in the oil tank 5 is maintained at the cooking temperature (for example, 180 ° C. to 182 ° C.). ON / OFF control for intermittently combusting the air-fuel mixture at the step (a). In addition, an operation panel 33 having operation buttons, a display unit, and the like is provided on the front upper portion of the housing 2, and a fly controller 32 that sets a cooking mode, a warming mode, a cooking temperature, and the like and inputs an instruction to the burner controller 31 is provided. Have been.

As shown in FIG. 4, the first temperature sensor 34 has a thermistor 36 directed rearward in the oil tank 5 around an axis of a cylindrical body 35 that penetrates the oil tank 5 from the front and projects the tip into the oil tank 5. Here, the thermistor 36 is installed so as to be positioned lower than the uppermost surface height L of the tail pipe 11 (the minimum required oil level).
Further, in the oil tank 5, a second temperature sensor 37, which also has a cylindrical body 38 and a thermistor 39, is installed so that the thermistor 39 is located above the uppermost surface height L of the tail pipe 11. . The temperature detection signal of the second temperature sensor 37 is also input to the burner controller 31.

  The lid 8 has a rectangular cylindrical arm 40 and an aluminum lid main body 41 connected to the arm 40 and fitted to the opening 6 of the oil tank 5. At the center in the longitudinal direction of the arm 40, a handle shaft 42 having a cross-shaped handle 43 at the upper end is screwed, and the center of the upper surface of the lid main body 41 is connected to the lower end of the handle shaft 42. Here, the rear end of the arm 40 is rotatably connected by a left-right rotation shaft 44 provided at the rear of the oil tank 5, so that the lid 8 is moved from the folded position shown by the solid line in FIG. As shown in the figure, the up-and-down operation can be performed up to a standing position rotated 87 ° rearward, which is regulated by a stopper (not shown) provided on the rear side of the rotating shaft 44. A torsion coil spring 44a is provided on the rotating shaft 44 to urge the arm 40 to the upright side. The upright position is a position slightly inclined forward from 90 ° in the vertical direction, but the center of gravity G of the lid 8 is located behind the axis O1 of the rotating shaft 44, that is, the axis O1 of the rotating shaft 44. It is set so as to be located behind the vertical virtual line S passing through. Therefore, the upright position of the lid 8 is maintained even when the lid 8 is tilted forward at 87 °.

Then, by rotating the handle 43 at the lying position of the lid 8, the handle shaft 42 is screwed to open the lid body 41 to close the opening 6 of the oil tank 5 and to open upward from the opening 6. Position can be moved up and down. On the back surface of the lid main body 41, a packing 45 that contacts the opening 6 at the closed position is provided over the entire circumference.
On the other hand, at the front end of the arm 40, a pair of left and right triangular operation plates 46, 46 provided with a gripping bar 47 on the lower end and a lock bar 48 on the inner side around a connecting shaft 49 provided in the arm 40. It is connected to be able to swing back and forth. A pair of left and right locking plates 50, 50 capable of locking the lock rod 48 when the oil tank 5 is closed by the lid body 41 are provided on the front surface of the oil tank 5.

In the pressure fryer 1 configured as described above, when performing pressure cooking, the lid 8 is closed in a state where the oil tank 5 is filled with cooking oil and food is stored. That is, when the arm 40 is rotated toward the front while holding the gripping bar 47 from the front side of the housing 2 and swinging the operation plate 46 outward, the lid body 41 also follows and rotates forward, and the opening of the oil tank 5 is opened. 6 move above. At this time, the lid 8 in the upright position is inclined forward from 90 ° as described above, and the grip bar 47 is provided at the front end of the operation plate 46 protruding forward from the arm 40. The person can easily hold the grip bar 47 and close the lid 8 without leaning over the oil tank 5 greatly.
Thereafter, when the operation plate 46 is pushed inward, the lock rod 48 is locked to the locking plates 50, 50, and the lid 8 is held at the lying position where the oil tank 5 is closed.
From here, when the handle 43 is rotated clockwise and the handle shaft 42 is screwed downward, the lid body 41 in a horizontal position moves downward in parallel, so that the entire periphery of the packing 45 is simultaneously brought into contact with the opening 6 and pressed, and the oil tank is pressed. 5 is sealed.

  When the operation switch on the operation panel 33 is turned on after the oil tank 5 is closed in this way, the burner controller 31 intermittently operates the pulse combustor 7 based on the detected temperature obtained from the first temperature sensor 34, and Is maintained at a predetermined standby temperature (for example, 120 ° C.), and oil / water determination is performed together with the heat / temperature control to determine whether cooking oil or water is charged in the oil tank 5. Execute control. Hereinafter, the heat retention / temperature control and the oil / water determination control will be described with reference to the flowchart of FIG.

When the operation switch is turned on, first, in S1, it is determined whether or not the detected temperature T exceeds 220 ° F (about 104 ° C). If the temperature exceeds 220 ° F., it means that the boiling temperature of water has been exceeded. Therefore, in S2, it is determined that cooking oil has been supplied, the oil / water determination control is terminated, and the heat retention / temperature adjustment control is performed. Do.
The heat retention / temperature control is performed by continuously burning the pulse combustor 7 until the detected temperature obtained from the first temperature sensor 34 reaches 250 ° F. (about 120 ° C.). Is intermittently burned (combustion of the pulse combustor 7 for 10 seconds and repetition of stoppage for 30 seconds) to maintain 250 ° F. (about 120 ° C.). The specific combustion operation of the pulse combustor 7 is such that the mixed gas is ignited by an ignition plug 51 (FIG. 3) provided in the combustion chamber 10 and explosively combusted in the combustion chamber 10. The operation of forcibly discharging the combustion exhaust gas to the tail pipe 11 due to the increase in the internal pressure and repeating the operation of sucking the fuel gas and the combustion air into the combustion chamber 10 which becomes a negative pressure due to the discharge of the combustion exhaust gas. .

On the other hand, if the detected temperature T is lower than 220 ° F. in S1, it is determined in S3 whether the detected temperature T exceeds 175 ° F. (about 79 ° C.). If the temperature exceeds 175 ° F., the detected temperature T is increased by continuously burning the pulse combustor 7 in S4. If it does not exceed 175 ° F, it is determined in S5 whether or not the detected temperature T is 135 ° F (about 57 ° C) or more. If it is below 135 ° F, the intermittent combustion is performed in S6. Let it start.
If it is determined in step S5 that the detected temperature T is equal to or higher than 135 ° F., or if it is confirmed that the detected temperature T has reached 135 ° F. due to intermittent combustion in step S6, a pulse is generated in step S7. The detected temperature T is raised by switching the combustor 7 to continuous combustion.

  Next, if it is determined in S8 that the detected temperature T has reached the first temperature of 175 ° F., a first timer of 80 seconds serving as a determination reference time in S9 (T1 in FIG. 6). Start. This determination reference time is one of the amount of water when the water is stored in the oil tank 5, the gas input to the pulse combustor 7, the gas supply pressure, the gas type, and the ambient temperature of the installation location of the pressure fryer 1. By changing a plurality of parameters, the time required for the detected temperature T to rise in the temperature range from 175 ° F to 195 ° F, which is higher than the liquefaction temperature of the solid oil used as cooking oil, is verified in advance. The time is set as a time shorter than the shortest time among the verified times, and is stored in a storage unit (not shown) of the burner controller 31 in advance.

Next, before the first timer T1 reaches 80 seconds in the determination of S10 (NO in this determination), the detected temperature T has reached the second temperature of 195 ° F. (about 91 ° C.) in the determination of S11. If this is confirmed (position O1 in FIG. 6), it is determined in S2 that cooking oil has been supplied, the oil / water determination control is terminated, and heat keeping / temperature control is performed.
Here, if the detected temperature T does not reach 195 ° F. (NO in S11) and T1 reaches 80 seconds (YES in S10, position W1 in FIG. 6), it is determined that water has been introduced. The procedure of S7 to S11 is a preliminary determination.
If water is determined in the preliminary determination, continuous combustion is continued, and it is determined in S12 whether or not the detected temperature T has reached 195 ° F., which is a temperature lower than boiling. The determination in S12 is also made after the execution of the continuous combustion in S4.

When the arrival at 195 ° F. is confirmed in S12, the second timer (T2 in FIG. 6) for 780 seconds (13 minutes) is started in S13 to switch the pulse combustor 7 to intermittent combustion.
Thereafter, during the counting by the second timer T2, when it is confirmed by the determination in S14 that the detected temperature T has reached 220 ° F., which is the over-boiling temperature (position O2 in FIG. 6), cooking oil is supplied in S2. When the determination is made that the oil-water determination control has been performed, the oil-water determination control is terminated, and the heat retention / temperature control is performed. On the other hand, if T2 reaches 780 seconds in the determination in S15 without the detected temperature T reaching 220 ° F. (position W2 in FIG. 6), it is determined in S16 that water has been charged, and the fly controller 32 The operation lamp blinks and an abnormal buzzer sounds, and an abnormal display such as “Mizkenshutsu” is displayed on the display of the operation panel 33 to notify the user. At the same time, the combustion of the pulse combustor 7 is stopped. The procedure of S12 to S16 is the main determination.

Then, when the cooking menu is selected during the heat retention / temperature control in S2 determined as cooking oil, the burner controller 31 determines the oil temperature in the oil tank 5 based on the detected temperature obtained from the first temperature sensor 34. ON / OFF control is performed so as to maintain the cooking temperature at a cooking temperature (for example, 180 ° C. to 182 ° C.).
On the other hand, the burner controller 31 obtains the temperature from the second temperature sensor 37 as a monitoring period from when the detected temperature obtained from the first temperature sensor 34 exceeds the cooking temperature (for example, 121 ° C.) to when the operation switch is turned off. The detected temperature is also acquired, and the abnormal heating is detected. Here, the difference between the detected temperatures of the first temperature sensor 34 and the second temperature sensor 37 is monitored, and when the temperature difference exceeds 40 ° C. for a predetermined time (for example, 1 second) or more, the temperature becomes empty. It is determined that a firing abnormality has occurred.

This occurs when the oil level in the oil tank 5 drops below the normal oil level L1 shown in FIG. 4 and drops below the same oil level L2 as the thermistor 39 of the second temperature sensor 37. Since the temperature detected by the thermistor 39 is reduced by being exposed to a region such as water vapor having no heat, the temperature difference between the temperature detected by the thermistor 36 of the first temperature sensor 34 located in the cooking oil is monitored. When the temperature difference has reached a predetermined temperature, it is determined that the oil level has dropped (the occurrence of idle heating).
When the burner abnormality is detected in this manner, the burner controller 31 stops the operation of the pulse combustor 7 and then rotates the fan 14 for a predetermined time (for example, 5 seconds). Then, the fly controller 32 displays an error on the display section of the operation panel 33, notifies the buzzer or an abnormal sound by an electronic sound, and stops the combustion of the pulse combustor 7.

  Thus, according to the pressure fryer 1 of the above-described embodiment, in the oil-water determination control, the burner controller 31 operates the pulse combustor 7 so that the detected temperature T from the first temperature sensor 34 is higher than the boiling temperature of water. Heat until the temperature reaches a low 195 ° F. When the detected temperature T reaches 195 ° F., the pulse combustor 7 is intermittently burned to reduce the capacity, and the heating is continued, and the detected temperature T is reduced to 195 ° F. When the temperature reaches 220 ° F higher than the boiling temperature within the second timer T2 from the arrival, the liquid in the oil tank 5 is determined to be cooking oil, and the detected temperature T does not reach 220 ° F within the second timer T2. By determining that the liquid in the oil tank 5 is water, it is possible to determine whether cooking oil or water is being charged into the oil tank 5 using an existing configuration without adding a new configuration. Easy to detect with Can be. In addition, since the capacity of the pulse combustor 7 is limited at the time of oil / water determination, boiling can be prevented even if water is charged into the oil tank 5.

In particular, here, when the burner controller 31 determines that the liquid in the oil tank 5 is water by the oil-water determination control, the burner controller 31 notifies the buzzer or the operation panel 33 of the notification means. It is possible to notify early that there is no oil, and it is possible to reduce the time loss until the state where cooking is possible.
Further, when the liquid in the oil tank 5 is determined to be water in the oil / water determination control, the operation of the pulse combustor 7 is stopped, so that useless energy consumption can be suppressed.

Further, before this determination, the temperature rise tendency until the detected temperature T reaches 195 ° F. from 175 ° F. is monitored, and when the detected temperature T reaches 195 ° F. within the first timer T1. Determines that cooking oil has been charged and ends the oil / water determination control. If the detected temperature T has not reached 195 ° F. within the first timer T1, it is determined that water has been charged. Since the determination is made and the final determination is made thereafter, when cooking oil is supplied, it is possible to eliminate the time loss associated with the oil-water determination and to heat the cooking oil to a temperature at which cooking can be performed early. Can be.
In particular, in the preliminary determination, the determination of oil or water is made based on whether the detected temperature T rises from 175 ° F. to 195 ° F. within a determination reference time (first timer T1) shorter than the shortest time assumed for water. Therefore, when the temperature reaches 195 ° F. within the determination reference time, it can be reliably determined that the cooking oil has been obtained, and subsequent determination is unnecessary, and time can be wasted.
Since the temperature zone in which the preliminary determination is performed is higher than the liquefaction temperature of the solid oil, the preliminary determination can be performed without reducing the detection accuracy even when the solid oil is used.

On the other hand, in this determination, the second temperature is set to 195 ° F. lower than the boiling temperature of water and the third temperature is set to 220 ° F. higher than the boiling temperature, and the heating in the second timer T2 is performed at 175 ° F. 195 ° F (intermittent combustion) than heating (intermittent combustion), so that it is possible to reliably determine whether cooking oil or water is used except when it is determined to be cooking oil in the preliminary determination. Is out.
In the preliminary determination, the shortest time for determining the first timer T1 is determined by the amount of water when the water is contained in the oil tank 5, the gas input of the pulse combustor 7, the gas supply pressure, the gas type, and the pressure fryer. By changing one or more parameters of the ambient temperature of the installation location of No. 1, each time required for the detected temperature T to rise from 175 ° F. to 195 ° F. is verified in advance, and the time of each verified time is verified. Since the first timer T1 is set to a shorter time as the shortest time, oil / water can be reliably determined.

The specific time of the first timer in the preliminary determination and the specific time of the second timer in the final determination are not limited to the above-described embodiments, but may be changed as appropriate in accordance with the configuration of the oil tank and the mode of the heating means (gas burner, electric heater, etc.). It is possible. Therefore, the capacity limitation in the second timer is not limited to the intermittent combustion, of course, and is not limited to the intermittent combustion, but may be appropriately selected such as reducing the heating power in continuous combustion or reducing the number of burners burned. No problem.
Further, the first to third temperatures are not limited to the temperatures in the above embodiment, but can be changed as appropriate.
Further, other configurations of the pressure fryer can be changed as appropriate. For example, a temperature sensor other than the thermistor can be used as the temperature sensor. Also, even if the pressure fryers are not a single oil tank but are arranged side by side on the left and right, the oil / water determination control can be executed individually by using the temperature sensors installed for each oil tank. Further, the present invention is applicable to a fryer without a lid.

  1. pressure fryer, 2. housing, 3. frame, 4. top panel, 5. oil tank, 6. opening, 7. pulse burner, 8. lid, 10. combustion chamber , 11 · · tail pipe, 31 · · burner controller, 32 · · fly controller, 33 · · · operation panel, 34 · · · first temperature sensor, 35 · 38 · · · cylinder, 36, 39 · · thermistor, 37 · -2nd temperature sensor, 40-Arm, 41-Lid body, 42-Handle axis, 43-Handle, 44-Rotation axis, 46-Operation plate. 50 ... locking plate.

Claims (3)

An oil tank containing cooking oil,
Heating means for heating the cooking oil in the oil tank,
Temperature detection means for detecting the temperature of the cooking oil,
A controller that controls the heating means and performs oil / water determination control to determine whether the liquid in the oil tank is cooking oil or water based on the temperature detected from the temperature detection means,
The controller may further include, when water is contained in the oil tank and heated by the heating means, the detection may be performed from a predetermined first temperature in a temperature zone lower than a boiling temperature of water to a second temperature higher than the predetermined temperature. Preliminarily set a judgment reference time shorter than the shortest time required for the temperature to rise,
In the oil / water determination control, the controller operates the heating unit until the detected temperature reaches the second temperature from the first temperature, and the controller detects the first temperature within the determination reference time. When the second temperature is reached from the temperature of the above, while the liquid in the oil tank is determined as cooking oil,
If the detected temperature has not reached the second temperature from the first temperature within the determination reference time, the heating by the heating means is continued and a predetermined time after the second temperature is reached. If the detected temperature reaches a third temperature higher than the second temperature within the time, it is determined that the liquid in the oil tank is cooking oil, and the detected temperature is within the predetermined time within the predetermined time. 3. The fryer according to claim 3, wherein the liquid in the oil tank is determined to be water if the temperature of the oil tank has not been reached.   The second temperature is a temperature lower than the boiling temperature of water, the third temperature is a temperature higher than the boiling temperature, and heating within the predetermined time is performed by changing the second temperature from the first temperature to the second temperature. The fryer according to claim 1, wherein the heating is performed at a lower capacity than the heating up to the temperature.   The shortest time is the amount of water when water is contained in the oil tank, the gas input when the heating means is a pulse combustor, the gas supply pressure, the gas type, and the ambient temperature of the installation location of the oil tank. By changing one or a plurality of parameters, and previously verifying each time required for the detected temperature to rise from the first temperature to the second temperature, and the shortest time among the verified times. The flyer according to claim 1 or 2, wherein

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