JP7744673B2 - Flyer - Google Patents

Description

This disclosure relates to a commercial fryer that heats cooking oil in an oil tank and cooks food by placing it in the oil tank.

As disclosed in Patent Document 1, the fryer has an oil tank that contains cooking oil, a heating means such as a burner or pulse burner that heats the cooking oil, and a control means that controls the heating means. Before cooking, the control means controls the heating means to maintain a predetermined standby temperature (e.g., 160°C) (standby mode), and when food such as potatoes is added, controls the heating means so that the temperature of the cooking oil changes along a predetermined control line (cooking mode). In particular, the fryer in Patent Document 1 minimizes the amount of cooking oil stored in the oil tank and periodically replenishes cooking oil that has been absorbed by the food during cooking and reduced in volume.

Patent No. 5340962

In conventional fryers such as those described in Patent Document 1, if the cooking oil capacity is reduced, overshooting, in which a small amount of heat causes the cooking oil temperature to rise excessively above the target temperature, is more likely to occur in standby mode. On the other hand, because the overall heat capacity of the cooking oil is reduced, when food is added in cooking mode, undershooting, in which the cooking oil temperature drops suddenly due to the food and the heat of vaporization generated by heating the food, is more likely to occur.

The present disclosure therefore aims to provide a fryer that can effectively prevent overshoot in standby mode and undershoot in cooking mode, even when the volume of cooking oil is reduced.

In order to achieve the above object, the present disclosure provides an oil tank capable of accommodating cooking oil;
a temperature detection means for detecting the temperature of the cooking oil;
a heating means provided in the oil tank and turned on/off to heat the cooking oil;
a control means for controlling the heating means, the control means including a timer and a memory unit;
an operation means for inputting an instruction to the control means,
the control means executes a standby mode in which the control means controls ON/OFF of the heating means so that the temperature detected by the temperature detection means is in line with a predetermined standby temperature before cooking begins;
After cooking starts, the fryer executes a cooking mode in which the heating means is controlled to be turned on and off so that the detected temperature changes from the standby temperature at the start of cooking along a predetermined control line set by variables of the elapsed time from the start of cooking and a predetermined target temperature,
In the standby mode, the control means sets a first upper limit temperature at which the heating means is switched from ON to OFF to a temperature that is lower than the standby temperature by a predetermined temperature, and sets a first lower limit temperature at which the heating means is switched from OFF to ON to a temperature that is lower than the first upper limit temperature by a predetermined first temperature width;
In the cooking mode, the second upper limit temperature at which the heating means is switched from ON to OFF is set to a temperature that is a predetermined temperature higher than the control line, and the second lower limit temperature at which the heating means is switched from OFF to ON is set to a temperature that is equal to or higher than the control line and that is lower than the second upper limit temperature by a predetermined second temperature width that is wider than the first temperature width.

According to the present disclosure, in standby mode, the heating means is controlled to turn on/off within a first temperature range that is lower and smaller than the standby temperature, thereby effectively preventing overshoot even when the cooking oil is reduced in volume. Furthermore, in cooking mode, the heating means is controlled to turn on/off within a temperature range that is higher than the control line and larger than the first temperature range, thereby effectively preventing undershoot even when the cooking oil is reduced in volume.

FIG. FIG. 1 is a schematic diagram of a fryer. FIG. 2 is an explanatory diagram of an operation panel. 4A and 4B are explanatory diagrams of ON/OFF control in a standby mode and a cooking mode.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.
Fig. 1 is a perspective view showing an example of a fryer, and Fig. 2 is a schematic diagram of the fryer. This fryer 1 has a pair of left and right oil vats 3, 3 in the upper part of a vessel body 2. A pair of left and right pulse combustors 4, 4 serving as heating means is provided at the bottom of each oil vat 3. Each pulse combustor 4 has a combustion chamber 5 provided on the inner wall at the front of the oil vat 3 and a tail pipe 6 connected to the combustion chamber 5 and routed in a serpentine manner within the oil vat 3.
The oil tanks 3 and their combustion and exhaust systems have the same configuration on both sides, so the following description will mainly focus on the oil tank 3 on the left side of FIG.

The oil vat 3 has a first cooking section 7 and a second cooking section 8. The first cooking section 7 is formed above the pulse burner 4 and has a rectangular cylindrical shape with an opening area that does not change vertically. The second cooking section 8 is located above the first cooking section 7 and has an inverted tapered shape that widens in all directions as it moves upward from the top of the first cooking section 7. The cooking oil is stored in the area up to the top of the second cooking section 8. A basket 9 containing food to be cooked, such as potatoes, can be placed in the oil vat 3. A net 10 for receiving the basket 9 is provided above the pulse burners 4, 4.
A first oil surface temperature sensor 11 is provided near the upper end surface of the first cooking section 7. A second oil surface temperature sensor 12 is provided near the upper end surface of the second cooking section 8. A cooking temperature sensor 13 is provided in the oil vat 3 near the tail pipe 6 of the pulse burner 4. An electric heater 33 is provided on the outer peripheral surface of the lower part of the oil vat 3.

An oil booster tank 14 for storing cooking oil is provided at the top of the appliance body 2, behind the oil vat 3. An oil booster pipe 15, which is connected to the second cooking section 8 at the rear of the oil vat 3, is connected to the underside of the oil booster tank 14. An oil booster valve 16, which can be opened and closed manually, is provided on the oil booster pipe 15. An oil booster temperature sensor 17 is provided inside the oil booster tank 14 to detect the temperature of the cooking oil stored therein.
An overflow section 18 is provided on the front surface of the fuel tank 14. The overflow section 18 is formed by piping connected to the front surface of the fuel tank 14, a flow path formed in the vertical direction to the front surface of the fuel tank 14, etc. The upper end of the overflow section 18 is connected to and hangs down from an opening formed at the upper front surface of the fuel tank 14, and the lower end of the overflow section 18 is connected to the rear inner surface of the oil tank 3 via an outlet 19. Therefore, when the cooking oil in the fuel tank 14 exceeds the lower edge of the opening, the overflowing cooking oil flows from the outlet 19 along the rear inner surface of the oil tank 3 and into the oil tank 3.

An air chamber 20 is provided outside the front side of the oil tank 3. A mixing chamber (not shown) communicating with the combustion chamber 5 is provided within the air chamber 20. A gas conduit 21 equipped with a gas electromagnetic valve 22 is connected to the mixing chamber to supply fuel gas. An air supply pipe 23 is also connected to the mixing chamber. The air supply pipe 23 is connected to a fan 24 provided at the bottom of the vessel body 2 to supply combustion air.
The tail pipes 6, 6 of the pulse combustors 4, 4 are arranged in a serpentine shape below the oil tank 3 and then connected to exhaust pipes 25, 25 drawn out from the air chamber 20. These exhaust pipes 25, 25 have mufflers 26, 26 arranged at the rear of the vessel body 2. The mufflers 26, 26 are arranged facing upward while in contact with the rear surface of the fuel tank 14, allowing the exhaust gas from combustion to be discharged.
The fuel tank 14 and mufflers 26, 26 are covered by exhaust pipe covers 27 provided on the body 2. Protective covers 28 are provided on the front of the left and right exhaust pipe covers 27, 27. Basket hangers 29, 29 for suspending and supporting the baskets 9, 9 are fixed to the protective covers 28. The outlet 19 of the overflow section 18 is provided below the basket hangers 29.

A filtering tank 30 with a filter at the bottom is provided at the bottom of the vessel body 2. An oil drain pipe 31 is connected to the bottom of the oil vat 3, and cooking oil in the oil vat 3 can be drained through the oil drain pipe 31 into the filtering tank 30. The oil drain pipe 31 is provided with an oil drain valve 32 that can be opened manually.
A filtering pump 35 is provided at the bottom of the device body 2. The suction side of the filtering pump 35 is connected to the bottom of the filtering tank 30 via a suction pipe 36. The discharge side of the filtering pump 35 branches into a first fuel supply pipe 37 and a second fuel supply pipe 38. The first fuel supply pipe 37 is connected to the fuel supply pipe 15 upstream of the fuel supply valve 16. The first fuel supply pipe 37 is provided with a first fuel supply valve 39 that can be opened and closed manually.
The second fuel supply pipe 38 is connected to the lower part of the oil tank 3. The second fuel supply pipe 38 is provided with a second fuel supply valve 40 that can be opened and closed manually.

An oil top-up tank 45 using a 18L can is provided below the oil tank 3. The oil top-up tank 45 is placed on a stand 46 provided on the vessel body 2. The stand 46 is provided with a heat retention heater 47 for heating the oil top-up tank 45 and a tank temperature sensor 48 for detecting the temperature of the oil top-up tank 45.
The lower end of an oil addition pipe 49 is inserted into the oil addition tank 45. The upper end of the oil addition pipe 49 is connected to the oil tank 3 above the second cooking section 8. An oil addition pump 50 and an oil addition solenoid valve 51 are provided on the oil addition pipe 49 from the upstream side.

A fry controller 60 is provided on the upper front surface of the appliance body 2. The fry controller 60 has an operation panel 61. As shown in Fig. 3, the operation panel 61 is provided with a power switch 62, a plurality of cooking buttons 63, 63..., displays 64, 64 for the selected cooking mode and maintenance menu, etc., as well as a mode selection button 65 for selecting the cooking mode and rated amount indicator lamps 66A, 66B for displaying the rated amount. The rated amount indicator lamp 66A corresponds to the first rated amount, and the rated amount indicator lamp 66B corresponds to the second rated amount.
A burner controller 70 is provided at the bottom of the appliance body 2. The burner controller 70 includes a timer 71 and a memory unit 72, and controls the ON/OFF of the pulse combustor 4 according to the cooking mode instructed by the fry controller 60 to cook food such as potatoes. Detection signals from the first and second oil surface temperature sensors 11 and 12, the cooking temperature sensor 13, the oil top-up temperature sensor 17, the tank temperature sensor 48, etc. are input to the burner controller 70. Based on these detection signals and instructions from the operation panel 61, the burner controller 70 controls the pulse combustor 4, the gas solenoid valve 22, the fan 24, the electric heater 33, the filtering pump 35, the heat retention heater 47, the oil top-up pump 50, the oil top-up solenoid valve 51, etc.

In the fryer 1 configured as described above, the amount of food to be cooked at one time is defined as two types: a predetermined first rated amount and a larger second rated amount, and cooking is possible in a first cooking mode corresponding to the first rated amount and a second cooking mode corresponding to the second rated amount. The oil tank 14 is filled with cooking oil (additional oil amount).
When the cook turns on the power switch 62 on the operation panel 61, the burner controller 70 rotates the fan 24 for a predetermined time to supply air, and then intermittently burns the mixed gas in the combustion chamber 5, turning the pulse combustor 4 on and off. That is, the mixed gas is ignited in the combustion chamber 5, causing it to explode and burn within the combustion chamber 5. The pressure increase within the combustion chamber 5 caused by the combustion forcibly discharges the combustion exhaust into the tailpipe 6. Then, fuel gas and combustion air are drawn into the combustion chamber 5, which is now under negative pressure due to the discharge of the combustion exhaust. This on and off operation is repeated, heating the cooking oil stored in the oil tank 3.

Before cooking begins, the burner controller 70 monitors the detected temperature obtained from the cooking temperature sensor 13 and executes a standby mode in which the pulse burner 4 is controlled to be turned ON/OFF so that the detected temperature is maintained at a predetermined standby temperature Ts (e.g., 160°C).
However, in this standby mode, as shown in FIG. 4 , the first upper limit temperature Ts1 at which the pulse combustor 4 is switched from ON to OFF is set to a temperature (Ts − 1°C) 1°C lower than the standby temperature Ts indicated by the dotted line. Furthermore, the first lower limit temperature Ts2 at which the pulse combustor 4 is switched from OFF to ON is set to a temperature (Ts − 2°C) that is lower than the first upper limit temperature Ts1 by a first temperature width (here, 1°C). In other words, ON/OFF control is performed within a first temperature width that is lower than the standby temperature Ts. Therefore, in the standby mode, when the pulse combustor 4 is turned ON and the detected temperature shows an upward trend, the pulse combustor 4 is quickly turned OFF at a temperature lower than the standby temperature Ts, as indicated by the solid line. This prevents excessive temperature rise (overshoot). Furthermore, because the temperature width from OFF to ON of the pulse combustor 4 is small, the amount of heat imparted to the cooking oil is reduced, effectively preventing overshoot.

While the standby mode is being executed, the fry controller 60 notifies the user by outputting a message indicating that cooking is OK on the display unit 64 of the operation panel 61, for example.
The cook then selects either the first or second cooking mode using the mode selection button 65, places a basket containing the corresponding rated amount of food into the oil vat 3, and presses the cooking start button (here, the cooking button 63 on the far left).The burner controller 70 then heats and cooks the food using the cooking time and heat amount of the pulse combustor 4 that are preset corresponding to the rated amount.
The target temperature at the start of cooking is set as a standby temperature Ts, and a control line L (shown as a straight, dashed-dotted line in FIG. 4 ) corresponding to each cooking mode is stored in the memory unit 72 of the burner controller 70. The target temperature is set based on variables such as the time elapsed since the start of cooking and the target temperature, and the control line L changes linearly, curved, or stepwise. From cooking start time t1, the burner controller 70 controls the pulse combustor 4 to turn on and off so that the detected temperature is maintained along the control line L corresponding to the selected cooking mode.

However, in each cooking mode, as shown in Fig. 4, the second upper limit temperature T _L1 at which the pulse combustor 4 is switched from ON to OFF is set to a temperature 2°C higher than the control line L. Also, the second lower limit temperature T _L2 at which the pulse combustor 4 is switched from OFF to ON is set to a temperature on the control line L and lower by a second temperature width (here, 2°C) wider than the first temperature width. In other words, ON/OFF control is performed in a large temperature range that is equal to or higher than the standby temperature Ts and the control line L. Therefore, in the cooking mode, the temperature range in which the pulse combustor 4 is ON/OFF controlled shifts to a higher temperature range than in the standby mode. Therefore, as shown by the solid line, even if the detected temperature shows a downward trend due to the addition of food to be cooked, the pulse combustor 4 is turned ON in a quick response, thereby preventing an excessive temperature drop (undershoot).
When cooking time t2 is up, fry controller 60 sounds an alarm to notify the user that cooking is complete, and the cook then removes basket 9 from oil tank 3. If the cook wishes to continue cooking, he or she can simply add food to the frying pan and press the cooking start button, and the same control process will be repeated.

Meanwhile, during operation in each cooking mode, the burner controller 70 monitors the detected temperature obtained from the tank temperature sensor 48 and controls the heat retention heater 47 to turn on and off so that a predetermined heat retention temperature is maintained in the oil tank 45.
When the first and second oil surface temperature sensors 11, 12 detect a decrease in the amount of cooking oil required in any of the cooking modes, or when a predetermined number of cooking cycles is reached, the oil top-up pump 50 is driven to open the oil top-up electromagnetic valve 51. Then, the cooking oil liquefied in the oil top-up tank 45 is supplied directly to the oil vat 3 via the oil top-up pipe 49.

As described above, the fryer 1 of the above configuration includes an oil vat 3 capable of accommodating cooking oil, a cooking temperature sensor 13 (temperature detection means) that detects the temperature of the cooking oil, a pulse combustor 4 (heating means) that is provided in the oil vat 3 and operates on/off to heat the cooking oil, a burner controller 70 (control means) that includes a timer 71 and a memory unit 72 and controls the pulse combustor 4, and an operation panel 61 (operation means) that inputs instructions to the burner controller 70. Before cooking starts, the burner controller 70 executes a standby mode in which it controls the pulse combustor 4 to turn on/off so that the temperature detected by the cooking temperature sensor 13 follows a predetermined standby temperature Ts, and after cooking starts, it executes a cooking mode in which it controls the pulse combustor 4 to turn on/off so that the detected temperature transitions from the standby temperature Ts at the start of cooking along a predetermined control line L that is set based on variables including the elapsed time since the start of cooking and a predetermined target temperature.
In the standby mode, the burner controller 70 sets a first upper limit temperature Ts1 at which the pulse combustor 4 is switched from ON to OFF to a temperature lower than the standby temperature Ts by a predetermined temperature, and sets a first lower limit temperature Ts2 at which the pulse combustor 4 is switched from OFF to ON to a temperature lower than the first upper limit temperature Ts1 by a predetermined first temperature width. In the cooking mode, the burner controller 70 sets a second upper limit temperature T _L1 at which the pulse combustor 4 is switched from ON to OFF to a temperature higher than the control line L by a predetermined temperature width, and sets a second lower limit temperature T _L2 at which the pulse combustor 4 is switched from OFF to ON to a temperature equal to or higher than the control line L and lower by a predetermined second temperature width wider than the first temperature width.

With this configuration, in standby mode, the pulse burner 4 is turned on/off over a first temperature range that is lower and smaller than the standby temperature Ts, effectively preventing overshoot even in the first cooking mode when the amount of cooking oil is small. Furthermore, in cooking mode, the pulse burner 4 is turned on/off over a temperature range that is higher than the control line L and larger than the first temperature range, effectively preventing undershoot even in the first cooking mode when the amount of cooking oil is small.

The following describes a modified example.
The values of the first upper limit temperature, the first temperature range, and the first lower limit temperature in the standby mode are not limited to the above-described form and can be changed as appropriate.
The values of the second upper limit temperature, the second temperature range, and the second lower limit temperature in the cooking mode are not limited to the above-described embodiment and can be changed as appropriate. For example, in the above-described embodiment, the second lower limit temperature is set on a linear control line, but it may be set higher than the control line.
The control line is not limited to the linear shape described above, but may be curved, stepped, or a combination thereof.
In the above embodiment, the first and second cooking modes can be implemented, but the cooking mode may be a single mode, or three or more cooking modes may be implemented. In either case, the cooking mode setting of the present disclosure is possible.

The fryer is not limited to one having a fry controller and a burner controller separately provided therein, but may be one having a single controller having both the functions of a fry controller and a burner controller.
The heating means may be formed solely by a pulse combustor or solely by an electric heater. The heating means may also be formed solely by a gas burner provided outside the oil vat. Furthermore, the heating means may be formed by a combination other than the combination of a pulse combustor and an electric heater.
In the above embodiment, a pair of oil tanks are provided on the left and right sides, but the number of oil tanks may be one, or conversely, three or more.
The present disclosure is also applicable to a pressure fryer in which the opening of the oil tank is closed with a lid.

DESCRIPTION OF SYMBOLS 1. Fryer, 2. Vessel body, 3. Oil tank, 4. Pulse burner, 5. Combustion chamber, 6. Tail pipe, 7. First cooking section, 8. Second cooking section, 9. Basket, 11. First oil surface temperature sensor, 12. Second oil surface temperature sensor, 13. Cooking temperature sensor, 14. Oil booster tank, 15. Oil booster pipe, 16. Oil booster valve, 18. Overflow section, 22. Gas solenoid valve, 30. Filtering tank, 35. Filtering port pump, 37: first fuel supply pipe, 38: second fuel supply pipe, 39: first fuel supply valve, 40: second fuel supply valve, 60: fry controller, 61: operation panel, 62: power switch, 63: cooking button, 64: display unit, 65: mode selection button, 66A, 66B: rated amount indicator lamp, 70: burner controller, 71: timer, 72: memory unit, Ts: standby temperature, Ts1: first upper limit temperature, Ts2: first lower limit temperature, T _L1 : second upper limit temperature, T _L2 : second lower limit temperature, L: control line.

Claims (1)

an oil tank capable of storing cooking oil;
a temperature detection means for detecting the temperature of the cooking oil;
a heating means provided in the oil tank and turned on/off to heat the cooking oil;
a control means for controlling the heating means, the control means including a timer and a memory unit;
an operation means for inputting an instruction to the control means,
the control means executes a standby mode in which the control means controls ON/OFF of the heating means so that the temperature detected by the temperature detection means is in line with a predetermined standby temperature before cooking begins;
After cooking starts, the fryer executes a cooking mode in which the heating means is controlled to be turned on and off so that the detected temperature changes from the standby temperature at the start of cooking along a predetermined control line set by variables of the elapsed time from the start of cooking and a predetermined target temperature,
In the standby mode, the control means sets a first upper limit temperature at which the heating means is switched from ON to OFF to a temperature that is lower than the standby temperature by a predetermined temperature, and sets a first lower limit temperature at which the heating means is switched from OFF to ON to a temperature that is lower than the first upper limit temperature by a predetermined first temperature width;
In the cooking mode, a second upper limit temperature at which the heating means is switched from ON to OFF is set to a temperature that is a predetermined temperature higher than the control line, and a second lower limit temperature at which the heating means is switched from OFF to ON is set to a temperature that is equal to or higher than the control line and that is lower than the second upper limit temperature by a predetermined second temperature range that is wider than the first temperature range.