JP7699809B2 - Flyer - Google Patents

Description

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

As disclosed in Patent Document 1, the fryer has an oil tank for storing cooking oil, a heating means such as a burner or a pulse burner for heating the cooking oil, and a control means for controlling the heating means. When food to be cooked, such as potatoes, is placed in the oil tank, the control means controls the heating means to perform cooking.
The control means has a control line set in which the detected temperature of the cooking oil obtained from a temperature detection means such as a thermistor changes as a continuous line or an intermittent stepped line depending on the variables of the elapsed time from the start of cooking and the target temperature. This control line is determined based on a cooking temperature zone surrounded by an allowable upper limit temperature and an allowable lower limit temperature for each elapsed time preset for cooking the food to be cooked.
When cooking is started, the control means controls the heating means (for example, controls the pulse burner to turn on and off) so that the detected temperature of the cooking oil changes along a control line within the cooking temperature zone.

Patent No. 5340962

However, when using such a fryer to cook with a small amount of cooking oil, the heat capacity of the cooking oil is reduced accordingly, and the temperature tends to change more sensitively and with a larger range depending on the addition of food to be cooked, the heat of vaporization generated during cooking, the amount of heat provided by the heating means, etc.
In addition, the cooking temperature zone is set based on the value measured by inserting a thermometer into the center of the cooking oil in which the food is directly heated and cooked, i.e., the value is affected by the heat of vaporization of the food, while the detected temperature is the temperature detected by a thermistor or the like installed on the wall of the oil vat, which is less affected by the food, and varies depending on the detection position and detection environment. Therefore, it is inevitable that there will be a discrepancy between the cooking temperature zone and the detected temperature, and simply controlling the ON/OFF so that the detected temperature does not exceed the cooking temperature zone will result in a large discrepancy between the actual temperature and the cooking temperature zone.

In this case, when cooking food such as frozen potatoes at around -20°C, immediately after the food is added, the food will remove a large amount of the heat contained in the cooking oil, and heat of vaporization will be generated as the water contained in the food evaporates, making it easy for the temperature of the food to undershoot, falling well below the cooking temperature range.
However, if the control line is carelessly set to a high temperature in the early stages of cooking, making it easier for the heating means to turn on, even if the temperature around the food shows a rising trend, there will be a certain time lag until that situation is transmitted to the thermistor installed on the wall.As a result, there will be a period of time during which unnecessary heat is applied, and the food will be given excessive heat, which may result in a poor finish.

The present disclosure therefore aims to provide a fryer that can prevent the actual temperature of the food from deviating from the cooking temperature range and maintain the quality of the food even when cooking the food with a small amount of cooking oil.

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 is provided in the oil tank and turns on/off to heat the cooking oil;
A control means having a timer and a memory unit and controlling the heating means,
The storage unit stores a cooking temperature zone surrounded by an allowable upper limit temperature, which is set in advance so as not to overheat the food to be cooked and which changes in a curved manner with time showing a downward trend and then an upward trend , and an allowable lower limit temperature, which is set in advance so as not to underheat the food to be cooked and which changes in a curved manner with time showing a downward trend and then an upward trend, and which has a minimum temperature, and a predetermined control line, which is set based on the cooking temperature zone and is determined by variables of the time elapsed from the start of cooking and a predetermined target temperature,
The control means controls ON/OFF of the heating means so that the temperature detected by the temperature detection means changes along the control line,
The control line is characterized in that, at the beginning of cooking, it is set within a first control region below the allowable lower limit temperature, at the middle of cooking, it is set within a second control region within the cooking temperature zone and the lower half of the cooking temperature zone, and at the end of cooking, it is set within a third control region within the cooking temperature zone and the upper half of the cooking temperature zone.
In addition, the control line in the early stage of cooking may be entirely set within the first control region, and may also be partially set within the second control region at a later timing leading up to the middle stage of cooking.
Similarly, the control line for the end of cooking may be set entirely within the third control region, or may be set partially within the second control region.
Another aspect of the present disclosure is characterized in that, in the above configuration , the temperature of the control line in the first control region is set to a value that is lower than the allowable lower limit temperature and higher than the minimum temperature.
Another aspect of the present disclosure is characterized in that, in the above configuration, the control line in the second control region is set to approach the median between the upper and lower allowable temperatures over time when the lower allowable temperature exceeds the minimum temperature and shows an upward trend.

According to the present disclosure, even when cooking food with a small amount of cooking oil, the actual temperature of the food can be prevented from deviating from the cooking temperature range, and the cooked food can be maintained at a good quality.
According to another aspect of the present disclosure, in addition to the above effects , the temperature of the control line in the first control region is set to a value below the allowable lower limit temperature and above the minimum temperature, thereby preventing undershoot from occurring due to excessive heating by the heating means.
According to another aspect of the present disclosure, in addition to the above effects, when the allowable lower limit temperature exceeds the minimum temperature and shows an upward trend, the control line in the second control region approaches the median between the allowable upper limit temperature and the allowable lower limit temperature over time, thereby suppressing a sudden increase in the actual measured temperature.

FIG. FIG. 1 is a schematic diagram of a fryer. FIG. 2 is an explanatory diagram of an operation panel. FIG. 2 is an explanatory diagram of cooking temperature zones and control lines.

Hereinafter, an embodiment 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 is provided with 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.
Since the configurations of the oil tanks 3 and their combustion and exhaust systems are the same on the left and right sides, 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 is a square tube with an opening area that does not change in the vertical direction. The second cooking section 8 is located above the first cooking section 7, and is formed in an inverted taper shape that widens in all directions from the top end of the first cooking section 7 upwards. The top end of the second cooking section 8 serves as a storage section for cooking oil. 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 near the tail pipe 6 of the pulse combustor 4 in the oil vat 3. An electric heater 33 is provided on the outer circumferential 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 unit 2 behind the oil vat 3. An oil booster pipe 15 that is connected to the second cooking section 8 at the rear of the oil vat 3 is connected to the bottom of the oil booster tank 14. An oil booster valve 16 that can be opened and closed manually is provided on the oil booster pipe 15. An oil booster temperature sensor 17 for detecting the temperature of the cooking oil stored in the oil booster tank 14 is provided inside the oil booster tank 14.
An overflow section 18 is provided on the front surface of the fuel tank 14. The overflow section 18 is formed by a pipe 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 an opening formed in the upper front surface of the fuel tank 14 and hangs down, 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 overflowed cooking oil flows from the outlet 19 down along the rear inner surface of the oil tank 3 into the oil tank 3.

An air chamber 20 is provided on the outside of the front side of the oil tank 3. A mixing chamber (not shown) communicating with the combustion chamber 5 is provided inside the air chamber 20. A gas conduit 21 equipped with a gas solenoid 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, and are capable of discharging the combustion exhaust gas.
The fuel tank 14 and the mufflers 26, 26 are covered by an exhaust pipe cover 27 provided on the body 2. Protective covers 28 are provided on the front sides 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 having 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 to 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 is manually opened and closed.
The second oil supply pipe 38 is connected to the lower part of the oil tank 3. The second oil supply pipe 38 is provided with a second oil supply valve 40 that can be opened and closed manually.

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

A fry controller 60 is provided on the upper front surface of the device 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 a maintenance menu, etc., as well as a mode selection button 65 for selecting a cooking mode, and rated amount display lamps 66A, 66B for displaying the rated amount. The rated amount display lamp 66A corresponds to the first rated amount, and the rated amount display lamp 66B corresponds to the second rated amount.
A burner controller 70 is provided at the bottom of the device body 2. The burner controller 70 includes a timer 71 and a memory unit 72, and controls ON/OFF of the pulse burner 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 refill 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 burner 4, the gas solenoid valve 22, the fan 24, the electric heater 33, the filtering pump 35, the heat retention heater 47, the oil refill pump 50, the oil refill solenoid valve 51, etc.

In the fryer 1 configured as described above, the amount of food to be cooked at one time is set to two types, a first rated amount and a second rated amount that is larger than the first 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 cooking oil tank 14 is filled with cooking oil (refilled oil amount).
When a cook turns on the power switch 62 of 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 to turn the pulse combustor 4 on and off. That is, the mixed gas is ignited in the combustion chamber 5 to cause it to explode and burn in the combustion chamber 5, and the combustion exhaust is forcibly discharged to the tail pipe 6 due to the increase in pressure in the combustion chamber 5 caused by the combustion. Then, fuel gas and combustion air are sucked into the combustion chamber 5, which is placed under negative pressure due to the discharge of the combustion exhaust. This on and off operation is repeated to heat 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 (e.g., 160°C).
When the standby mode is being executed, the fry controller 60 notifies the user by, for example, outputting a display indicating that cooking is OK on the display unit 64 of the operation panel 61 .
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 to be cooked into the oil vat 3, and presses the cooking start button (here, the cooking button 63 on the left side).Then, the burner controller 70 heats and cooks the food to be cooked using the cooking time and heat amount of the pulse burner 4 that are preset corresponding to the respective rated amounts.

A cooking temperature zone V surrounded by an allowable upper limit temperature T1 and an allowable lower limit temperature T2 that change with time, as shown by the dashed line in Fig. 4, is set in the memory unit 72 of the burner controller 70. This cooking temperature zone V forms a curve that shows a downward trend and then an upward trend over time, and the allowable lower limit temperature T2 has a minimum temperature Tmin at the point where the downward and upward trends are reversed. Based on this cooking temperature zone V, the memory unit 72 sets, for each cooking mode, discontinuous control lines L1 to L3 (shown by solid lines) in which the target temperature at the start of cooking changes in a stepped manner depending on the variables of the elapsed time from the start of cooking and the target temperature.
However, in each cooking mode, the control line L1 at the beginning of cooking from cooking start time t0 to first elapsed time t1 is set within a first control region E1 below the allowable lower limit temperature T2 of the cooking temperature zone V. However, the control line L1 is set to be above the minimum temperature Tmin and to be within a second control region E2, part of which is in the lower half of the cooking temperature zone V immediately before the first elapsed time t1.
Next, the control lines L2, L2... in the middle of cooking from the first elapsed time t1 to the second elapsed time t2 are each set within the cooking temperature zone V and within the second control region E2 which is the lower half of the cooking temperature zone V. Note that the control line L2 after the allowable lower limit temperature T2 exceeds the minimum temperature Tmin and shows an upward trend is set so as to gradually approach the median Tmid between the allowable upper limit temperature T1 and the allowable lower limit temperature T2 as time passes.
Control line L3 for the end of cooking from second elapsed time t2 to third elapsed time t3 at which cooking ends is set within cooking temperature zone V and within third control region E3, which is the upper half of cooking temperature zone V. However, control line L3 is set such that a portion of it is within second control region E2 immediately before third elapsed time t3.

From cooking start time t0, the burner controller 70 controls the pulse combustor 4 to turn ON/OFF so that the detected temperature is maintained along the control lines L1, L2, and L3 corresponding to the selected cooking mode.
Therefore, in the early stage of cooking, ON/OFF control is performed based on the control line L1 in the first control region E1, so that excessive heat is not applied to the cooking oil, and overshooting can be suppressed. In this early stage of cooking, bubbles are generated from the food to be cooked, and the cooking oil is cooled by the heat of vaporization, so the temperature of the cooking oil is less likely to rise.
However, as cooking progresses, the number of generated bubbles decreases, and the temperature of the cooking oil tends to rise.
Therefore, during the middle of cooking, the control line L2 is set to the second control region E2 in the lower half of the cooking temperature zone V, thereby preventing the cooking oil from rising suddenly and preventing overshooting during the middle of cooking.

Then, at the end of cooking, the control line L3 is set to the third control region E3, which is the upper half of the cooking temperature zone V, so that the temperature of the cooking oil at the end of cooking can be close to the temperature at the start of cooking. This allows for a quick response to the heating of the next food item. At the end of cooking, the cooking of the food item has progressed considerably and there are fewer bubbles, so the effect of the heat of vaporization is small and the detected temperature is close to the actual temperature of the cooking oil around the food item. Therefore, even if the control line L3 is set to the third control region E3, which is the upper half of the cooking temperature zone V, there is little risk that the temperature of the cooking oil will suddenly exceed the cooking temperature zone V.
In this manner, the pulse burner 4 is turned on/off along each of the control lines L1 to L3, so that the actual cooking oil temperature (actual measured temperature) T changes within the cooking temperature zone V, as shown by the dotted line.
When the third elapsed time t3 is up, the fry controller 60 sounds an alarm to notify the completion of cooking, and the cook then removes the basket 9 from the oil tank 3. If the cook wishes to continue cooking, he or she can simply add food and press the cooking start button, and the same control process will be repeated.

On the other hand, 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 be turned ON/OFF so that a predetermined heat retention temperature is maintained in the top-up 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 times is reached, the oil top-up pump 50 is driven to open the oil top-up solenoid valve 51. Then, the cooking oil liquefied in the oil top-up tank 45 is directly supplied to the oil vat 3 via the oil top-up pipe 49.

Thus, the fryer 1 of the above embodiment includes an oil tank 3 capable of accommodating cooking oil, a cooking temperature sensor 13 (temperature detection means) for detecting the temperature of the cooking oil, a pulse burner 4 (heating means) provided in the oil tank 3 and turned on/off to heat the cooking oil, and a burner controller 70 (control means) equipped with a timer 71 and a memory unit 72 and for controlling the pulse burner 4. The memory unit 72 also stores a cooking temperature zone V consisting of an allowable upper limit temperature T1 and an allowable lower limit temperature T2 for each preset elapsed time, and predetermined control lines L1 to L3 that are set based on the cooking temperature zone V and are the variables of the elapsed time from the start of cooking and a predetermined target temperature. Furthermore, the burner controller 70 controls the pulse burner 4 to be turned on/off so that the temperature detected by the cooking temperature sensor 13 changes along the control lines L1 to L3.
The control lines L1 to L3 are set in a first control region E1 below the allowable lower limit temperature T2 at the beginning of cooking, in a second control region E2 within cooking temperature zone V and the lower half of cooking temperature zone V at the middle of cooking, and in a third control region E3 within cooking temperature zone V and the upper half of cooking temperature zone V at the end of cooking.
According to this configuration, even when cooking food with a small amount of cooking oil, the actual temperature T of the food can be prevented from deviating from the cooking temperature zone V, and the finished product of the food can be maintained at a good quality.

In particular, the allowable lower limit temperature T2 is defined as a curve that shows a downward trend and then an upward trend over time, and has a minimum temperature Tmin, and the temperature of the control line L1 in the first control region E1 is set to a value that is below the allowable lower limit temperature T2 and above the minimum temperature Tmin.
Therefore, it is possible to prevent the occurrence of undershoot caused by excessive heating by the pulse combustor 4 .
In addition, the control line L2 in the second control region E2 is set so that when the allowable lower limit temperature T2 exceeds the minimum temperature Tmin and shows an upward trend, it approaches the median Tmid between the allowable upper limit temperature T1 and the allowable lower limit temperature T2 over time.
Therefore, a sudden increase in the measured temperature T can be suppressed.

The following describes a modified example.
The cooking temperature zone and the control line are not limited to the above forms and can be changed as appropriate. For example, the cooking temperature zone may be linear, and the control line is not limited to the above form of an intermittent linear shape, but may be an intermittent curved shape, a continuous curved shape or a linear shape, etc. The lengths of the initial cooking stage, the middle cooking stage, and the final cooking stage are also not limited to the above forms.
In the above embodiment, a part of the control line at the beginning of cooking is set within the second control region, but the whole of the control line may be set within the first control region. Similarly, in the above embodiment, a part of the control line at the end of cooking is set within the second control region, but the whole of the control line may be set within the third control region.
In the above embodiment, the first and second cooking modes can be executed, but the cooking mode may be a single mode, or three or more cooking modes may be executed. In either case, the control line of the present disclosure can be set.

The fryer is not limited to one having a fry controller and a burner controller separately provided, 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 only of a pulse combustor or only of an electric heater. The heating means may be formed only of a gas burner provided outside the oil vat. Furthermore, the heating means may be formed of 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 oil tanks may be provided.
The present disclosure is also applicable to a pressure fryer in which the opening of the oil tank is closed with a lid.

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 pump, 37...first fuel supply pipe, 38...second fuel supply pipe, 39...first fuel supply valve Lube, 40: Second fuel supply valve, 60: Fry controller, 61: Operation panel, 62: Power switch, 63: Cooking button, 64: Display, 65: Mode selection button, 66A, 66B: Rated amount display lamp, 70: Burner controller, 71: Timer, 72: Memory unit, V: Cooking temperature range, T1: Upper limit temperature, T2: Lower limit temperature, Tmid: Median value, Tmin: Minimum temperature, L1-L3: Control lines, E1: First control area, E2: Second control area, E3: Third control area.

Claims (3)

an oil tank capable of storing cooking oil;
A temperature detection means for detecting the temperature of the cooking oil;
A heating means is provided in the oil tank and turns on/off to heat the cooking oil;
A control means having a timer and a memory unit and controlling the heating means,
The storage unit stores a cooking temperature zone surrounded by an allowable upper limit temperature, which is set in advance so as not to overheat the food to be cooked and which changes in a curved manner with time showing a downward trend and then an upward trend , and an allowable lower limit temperature, which is set in advance so as not to underheat the food to be cooked and which changes in a curved manner with time showing a downward trend and then an upward trend, and which has a minimum temperature, and a predetermined control line, which is set based on the cooking temperature zone and is determined by variables of the time elapsed from the start of cooking and a predetermined target temperature,
The control means controls ON/OFF of the heating means so that the temperature detected by the temperature detection means changes along the control line,
The control line is set in a first control region below the lower allowable temperature limit at the beginning of cooking, in a second control region within the cooking temperature zone and the lower half of the cooking temperature zone at the middle of cooking, and in a third control region within the cooking temperature zone and the upper half of the cooking temperature zone at the end of cooking. The fryer according to claim 1, characterized in that the temperature of the control line in the first control region is set to a value below the allowable lower limit temperature and above the minimum temperature. The fryer according to claim 2, characterized in that the control line in the second control region is set so that when the allowable lower limit temperature exceeds the minimum temperature and shows an upward trend, it approaches the median between the allowable upper limit temperature and the allowable lower limit temperature over time.

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