Fryer

Abstract

The invention provides a fryer capable of preventing oxidative deterioration of frying oil even in repeated use of the frying oil. The fryer is provided with an upper oil groove for frying cooking, a lower oil groove forcibly cooled by a water cooling jacket, a standby tank for storing frying oil discharged from the lower oil groove, and a return flow path for injecting the frying oil in the standby tank into the lower oil groove. The upper part of the standby tank is provided with a filter for removing oil residue from the frying oil, a bottom plate in the standby tank is inclined towards the deepest part of a storage part of the frying oil, a dip tube communicated with the return flow path is arranged in the storage part, and the front end of the dip tube is separated from the bottom plate of the standby tank.

Description

Technical Field

[0001] This invention relates to a fryer for cooking fried foods, and more particularly to a fryer in which a heater for heating frying oil is provided in the middle of the depth direction of the oil tank. Background Technology

[0002] Conventionally, deep fryers of this type are known to be configured such that a heater is disposed in the middle of the oil tank storing frying oil in the depth direction, an upper oil tank above the heater is used as a high-temperature section and the food is cooked in the upper oil tank, and a lower oil tank below the heater is used as a low-temperature section, so that the water and oil residue generated in the oil during the cooking of the food are collected by settling in the lower oil tank.

[0003] In particular, Patent Document 1 discloses a deep fryer equipped with a water-cooling jacket that covers the entire lower oil tank from the outside, forcibly cooling the lower oil tank. In this deep fryer, due to the cooling effect of the water-cooling jacket, the oil temperature in the lower oil tank is suppressed to below 60 degrees Celsius. Therefore, when moisture released from the food in the high-temperature upper oil tank settles into the lower oil tank due to its difference in specific gravity with the frying oil, this moisture does not vaporize but remains in the lower oil tank. Thus, it is possible to suppress oil splashing caused by boiling of the frying oil, promote the settling of oil residue relative to the lower oil tank, and reduce oil stains in the kitchen. Furthermore, since the vaporization of moisture in the oil tank can be prevented as much as possible, the deterioration of the frying oil accompanied by oxidation can be effectively prevented, thereby extending the oil replacement cycle.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 5901624 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In most commercial deep fryers designed for continuous, high-volume frying, an oil recovery tank is installed at the bottom of the oil tank within the casing to facilitate cleaning of the oil tank and reuse of the frying oil. For example, after a day's cooking operations, the empty oil tank can be cleaned by draining all the frying oil into the oil recovery tank. Then, after cleaning, the frying oil in the oil recovery tank is returned to the oil tank, allowing for repeated frying and cooking.

[0009] Regarding this point, in the fryer disclosed in Patent Document 1, as mentioned above, the moisture emanating from the food is not vaporized but is easily retained in the lower oil tank. Therefore, a large amount of moisture remains in the frying oil discharged from the oil tank into the oil recovery tank. Thus, when all the frying oil in the oil recovery tank is returned to the oil tank after the cleaning operation is completed, the moisture captured in the frying oil also returns to the oil tank. During the process of injecting frying oil from the oil recovery tank into the oil tank, the frying oil is stirred. Therefore, when the frying oil in the oil tank is heated again from this state, the moisture mixed in with the frying oil will vaporize, potentially accelerating the deterioration of the frying oil.

[0010] In addition, to increase the number of times the frying oil can be reused, it is passed through a filter when discharged from the oil tank to the oil recovery tank to remove oil residue. When filtering out the fine oil residue floating in the frying oil, the filter mesh needs to be fine enough. However, if the mesh is too fine, the frying oil will take longer to pass through the filter, requiring a corresponding increase in cleaning time. Furthermore, there is still a possibility that moisture contained in the frying oil may not be removed by the filter and may be stirred into the frying oil in the oil recovery tank.

[0011] Solution for solving the problem

[0012] The present invention was made in view of such a problem, and its object is to provide a deep fryer that can prevent moisture from returning to the oil tank and capture it in a spare tank even when a large amount of moisture released from the food during frying or cooking is contained in the frying oil without vaporization, thereby preventing the frying oil from oxidizing and deteriorating during repeated use.

[0013] That is, the present invention is a deep fryer that uses a heater to heat the frying oil accumulated in an oil tank and to fry food ingredients placed in the oil tank. It comprises: an upper oil tank equipped with the heater for frying food ingredients; a lower oil tank continuously arranged below the upper oil tank, having a discharge port at its deepest point to discharge oil residue generated in the oil tank along with the frying oil, and having multiple inclined bottom plates inclined towards the discharge port; a water-cooling jacket surrounding the lower oil tank and filled with cooling water to forcibly cool the frying oil in the lower oil tank; a discharge valve for opening and closing a discharge flow path connected to the discharge port; a spare tank for storing the frying oil flowing down from the oil tank through the discharge valve; and a return flow path having an oil pump for injecting the frying oil from the spare tank into the lower oil tank. Furthermore, the spare tank has a filter at the top to remove oil residue from the frying oil flowing into the spare tank, and the bottom plate inside the spare tank is inclined toward the deepest part of the frying oil accumulation section. A suction pipe communicating with the return flow path is disposed in the accumulation section, and the front end of the suction pipe is disposed separately from the bottom plate of the spare tank.

[0014] Invention Effects

[0015] According to the present invention, the bottom plate of the spare tank is inclined towards the deepest accumulation section. Therefore, when frying oil is discharged from the oil tank into the spare tank, the moisture contained in the frying oil gradually accumulates in the accumulation section within the spare tank. Furthermore, the tip of the suction pipe for returning the frying oil from the spare tank to the oil tank is disposed separately from the bottom plate in the accumulation section. Therefore, when the oil pump is driven to draw frying oil from the spare tank, a portion of the frying oil will not return to the oil tank but will remain in the spare tank. Thus, the moisture contained in the frying oil in the spare tank, while accumulating in the accumulation section, will not be drawn away by the suction pipe and will remain in the accumulation section.

[0016] That is, if the frying oil containing moisture is temporarily drained from the oil tank into a spare tank and then injected back into the oil tank from the spare tank, the moisture contained in the frying oil can be captured in the spare tank, so that even if the frying oil is used repeatedly, the deterioration of the frying oil caused by oxidation can be prevented as much as possible. Attached Figure Description

[0017] Figure 1 This is a schematic cross-sectional view illustrating an example of an embodiment of the fryer using the present invention.

[0018] Figure 2 This is a block diagram illustrating the control system of an fryer according to an embodiment.

[0019] Figure 3 This is a front view of the spare tank of the fryer shown in the embodiment.

[0020] Figure 4 This is a side view of the spare tank of the fryer according to an embodiment.

[0021] Figure 5 This is a top view of the spare tank of the fryer according to an embodiment. Detailed Implementation

[0022] The fryer of the present invention will now be described in detail with reference to the accompanying drawings.

[0023] Figure 1 An example of a commercial fryer using the present invention is shown. This fryer 1 is a self-standing type fryer used in the kitchens of restaurants, etc., and is capable of frying and cooking by adding about 18 liters of frying oil 10 to the oil tank.

[0024] The fryer 1 includes an oil tank 2 for storing frying oil, a housing 3 supporting the oil tank 2, a spare tank 4 housed below the oil tank 2 within the housing 3, and a discharge passage 5 for discharging frying oil from the oil tank 2 to the spare tank 4. A discharge valve 6 is provided in the discharge passage 5, configured such that opening the discharge valve 6 allows the frying oil in the oil tank 2 to flow towards the spare tank 4 by its own weight.

[0025] Furthermore, a mesh filter 7 is installed midway along the path from the discharge flow path 5 to the spare tank 4, whereby oil residue is captured as the oil flowing into the spare tank 4 passes through the filter 7. The mesh size of the filter can be 20-50 mesh, more preferably 30-40 mesh. While this also depends on the wire diameter of the metal wire forming the filter, for example, a 50 mesh has a mesh size of approximately 0.279 mm, allowing fine particles of oil residue to pass through. The reason for using a larger mesh size in the filter 7 to capture only larger oil residue is that a larger flow rate of the oil 10 passing through the filter 7 per unit time is set, thereby quickly discharging the oil 10 from the oil tank 2 into the spare tank 4. Details regarding the spare tank 4 will be described later.

[0026] The oil tank 2 is configured to include an upper oil tank 2a for frying and cooking, and a lower oil tank 2b continuously arranged below the upper oil tank 2a. A heater 8 for heating frying oil is provided in the upper oil tank 2a, which can heat the frying oil to any temperature by energizing the heater 8. On the other hand, the lower oil tank 2b has a discharge port connected to the discharge flow path 5 at its deepest part. A plurality of inclined base plates 20 are arranged around the discharge port, tilting towards it, and these inclined base plates 20 are connected to form the base plate of the oil tank 2. In the illustrated example, four inclined base plates 20 are arranged around the discharge port, so that the base plate of the oil tank 2 is in the shape of an inverted square pyramid.

[0027] Furthermore, the upper oil tank 2a is surrounded by a heat insulation member 21, while a water-cooled jacket 22 filled with cooling water is provided around the lower oil tank 2b. Therefore, when the heater 8 is energized, the frying oil 10 in the upper oil tank 2a, where the heater 8 is located and which is covered by the heat insulation member 21, is heated to a high temperature (e.g., 180°C). Meanwhile, the frying oil 10 in the lower oil tank 2b is forcibly cooled by the water-cooled jacket 22, and its temperature is maintained at a low temperature below 100°C (e.g., 60°C). It should be noted that, although not illustrated, the water-cooled jacket 22 is connected to a cooling water supply pipe and a discharge pipe, allowing the cooling water that has heated up due to the cooling of the lower oil tank 2b to be discharged to the outside, and new, low-temperature cooling water to be supplied.

[0028] The frying and cooking of the ingredients takes place in the upper oil tank 2a, where the frying oil is heated by the heater 8. Meanwhile, moisture and oil residue released from the ingredients into the frying oil during frying and cooking settle from the upper oil tank 2a to the lower oil tank 2b. As mentioned earlier, the frying oil 10 in the lower oil tank 2b is maintained at a low temperature below 100°C, so the moisture reaching the lower oil tank 2b does not vaporize but settles to the vicinity of the inclined bottom plate 20. Furthermore, the temperature of the frying oil 10 in the lower oil tank 2b is significantly lower than that in the upper oil tank 2a, so the frying oil does not convection from the lower oil tank 2b to the upper oil tank 2a, and the oil residue settling in the lower oil tank 2b does not rise to the upper oil tank 2a but accumulates on the plurality of inclined bottom plates 20.

[0029] On the other hand, a return flow path 40 is provided between the spare tank 4 and the oil tank 2, which can appropriately inject the frying oil 10 present in the spare tank 4 into the oil tank 2 by driving the oil injection pump 41. The return flow path 40 is connected to the oil tank 2 below the heater 8, and more specifically, it is connected to the boundary between the upper oil tank 2a and the lower oil tank 2b above the upper end of the inclined bottom plate 20 of the lower oil tank 2b.

[0030] Figure 2 This is a block diagram showing the control system of the fryer 1. The fryer 1 includes a power supply unit 11 that is powered by an AC power source, and a control unit 12 with a built-in microprocessor that receives power from the power supply unit 11 to control the operation of the oil pump 41, the heater 8, and the discharge valve 6. In addition, a temperature sensor 13 that measures the temperature of the frying oil 10 in the upper oil tank 2a is connected to the control unit 12. The control unit 12 refers to the output signal of the temperature sensor 13 at predetermined intervals and, according to a pre-stored program, instructs the power supply unit 11 to supply power to the heater 8 to maintain the frying oil 10 in the upper oil tank 2a at a predetermined temperature (e.g., 180°C).

[0031] The control unit 12 is connected to an operation panel 14, which serves as a user interface. The operation panel 14 is equipped with an UP button 15 and a DOWN button 16 for inputting cooking temperature, and a display unit 17 that shows the current temperature of the frying oil 10 in the upper oil tank 2a and the cooking temperature set using the UP button 15 and the DOWN button 16.

[0032] Additionally, the operation panel 14 includes a pump button 18 that indicates the discharge of all the frying oil 10 in the oil tank 2 into the spare tank 4. On the other hand, it also includes an oil filling button 19 that fills the empty oil tank 2 with the frying oil 10 from the spare tank 4. The pump button 18 is operated, for example, when the oil tank 2 is emptied and cleaning is desired. When this button 18 is operated, the discharge valve 6 is opened, and all the frying oil 10 in the oil tank 2 is discharged into the spare tank 4. The oil filling button 19 is operated when the frying oil 10 in the spare tank 4 is moved to the empty oil tank 2. When this button 19 is operated, the oil pump 41 is activated, and approximately all the frying oil 10 in the spare tank 4 is injected into the oil tank 2, filling it completely.

[0033] Furthermore, when replacing the used frying oil 10 in the oil tank 2 with new oil, after draining the used frying oil 10 into the spare tank 4 by operating the extraction button 18, the frying oil in the spare tank 4 is replaced with new frying oil, and then the oil tank 2 is filled with new frying oil 10 by operating the oil filling button 19. Thus, the user can easily perform the frying oil 10 replacement operation without lifting the heavy container containing the frying oil 10.

[0034] The control panel 14 is equipped with an oil residue discharge button 30, which discharges oil residue accumulated in the lower oil tank 2b to the outside of the oil tank 2 during frying and cooking in the oil tank 2. When the user operates the oil residue discharge button 30, the control unit 12 opens the discharge valve 6 for a predetermined time, and a predetermined amount (e.g., about 4 liters) of frying oil 10 in the lower oil tank 2b is discharged toward the spare tank 4. Simultaneously, the control unit 12 activates the oil injection pump 41 to inject frying oil 10 from the spare tank 4 into the oil tank 2.

[0035] Figures 3 to 5 This is a diagram showing the details of the spare tank 4.

[0036] The spare tank 4 is rectangular in shape with casters 42 on the bottom and a handle 43 on the front, allowing it to be easily pulled out from under the housing 3 when filled with a large amount of frying oil. The capacity of the spare tank 4 is set to be greater than the total amount of frying oil 10 in the oil tank 2, and in this embodiment, it is set to approximately 26 liters. The aforementioned filter 7 is provided at the upper center of the spare tank 4. The frying oil 10 discharged from the oil tank 2 passes through the filter 7 and flows into the spare tank 4, where the filter 7 collects oil residue. The filter 7 is provided with a handle 70, allowing the filter 7 to be removed from the spare tank 4 for disposal of the collected oil residue.

[0037] The bottom plate inside the spare tank 4 is configured to include: as follows Figure 3 As shown in the front view, the bottom plate 44a slopes to the left of the spare tank 4, as... Figure 4 The bottom plate 44b, as shown in the side view, slopes towards the front of the spare tank 4, and as shown in the side view... Figure 5 As shown in the top view, a horizontal base plate 44c is disposed at the left end of the front side of the spare tank 4. The base plate 44c is the deepest part of the spare tank 4 and functions as the initial accumulation point for the frying oil 10 in the spare tank 4, and is then accumulated to the final accumulation point 45. That is, when the amount of frying oil 10 in the spare tank 4 decreases, the frying oil 10 flows on the base plates 44a and 44b and accumulates in the accumulation point 45.

[0038] A suction pipe 46 communicating with the return flow path 40 is inserted inside the spare tank 4. This suction pipe 46 is disposed in the accumulation section 45, and its front end is separately disposed from the bottom plate 44c of the spare tank 4, thus ensuring that even when the oil pump 41 is activated, the frying oil in the spare tank 4 is not completely sucked up, leaving only a small amount of frying oil remaining in the accumulation section. Furthermore, the suction pipe 46 is detachable from the spare tank 4 and can be removed when the spare tank 4 is pulled out of the housing 3.

[0039] Furthermore, in the spare tank 4, when the oil residue discharge button 30 is operated, there is always a certain amount of frying oil 10 injected into the lower oil tank 2b, and this frying oil 10 exists in the accumulation section 45. Therefore, the capacity of the spare tank 4 is set to be greater than the capacity of the oil tank 2.

[0040] As already explained, when the extraction button 18 or the oil residue discharge button 30 is operated, the frying oil 10 in the oil tank 2 is discharged into the spare tank 4. At this time, the oil residue accumulated in the inclined bottom plate 20 in the lower oil tank 2b is discharged from the oil tank 2 together with the frying oil 10. Larger oil residue mixed with the discharged frying oil 10 is captured by the filter 7, but fine oil residue and moisture are not captured by the filter 7 and flow into the spare tank 4 as mixed with the frying oil 10.

[0041] Fine oil residue and moisture mixed in with the frying oil settle on the bottom plate of the spare tank 4 as the frying oil 10 is stored in the spare tank 4. For example, when the user presses the extraction button 18 on the operation panel 14 at the end of the day, the frying oil 10 is discharged from the oil tank 2 into the spare tank 4, and at the same time the oil pump 41 is driven for a specified time to clean the oil tank 2 using the frying oil circulating from the spare tank 4 to the oil tank 2. If the frying oil 10 discharged into the spare tank 4 is kept in the spare tank 4 in this state until the next morning, then at the start of the next day's business, fine oil residue and moisture settle on the bottom plate of the spare tank 4. At this time, the oil residue accumulates on the bottom plates 44a, 44b, and 44c of the spare tank, but because the bottom plates 44a and 44b are inclined, the moisture with a specific gravity greater than the frying oil flows on the bottom plates 44a and 44b and accumulates on the bottom plate 44c, which is the deepest part of the spare tank 4.

[0042] At the start of the next day's business, the user can press the oil filling button 19 on the operation panel 14 to return the frying oil 10 in the spare tank 4 to the oil tank 2. At this time, when the oil filling pump 41 is activated, the frying oil in the spare tank 4 is drawn out by the suction pipe 46 of the accumulation section 45 into the return flow path 40, and then injected into the oil tank 2 via the return flow path 40.

[0043] On the other hand, the tip of the suction pipe 46, used to return the frying oil 10 from the spare tank 4 to the oil tank 2, is separated from the bottom plate 44c, and a predetermined distance (e.g., 5 mm) is provided between the suction pipe 46 and the bottom plate 44c. Therefore, when the oil pump 41 is driven to draw frying oil 10 from the spare tank 4, at least a portion of the frying oil 10 present in the accumulation section 45 will not return to the oil tank 2 but will remain in the spare tank 4. Thus, the moisture contained in the frying oil 10 in the spare tank 4, while accumulating in the accumulation section 45, will not be drawn by the suction pipe 46 and will remain in the accumulation section 45.

[0044] That is, in the fryer 1 of this embodiment, if the frying oil 10 containing water is temporarily discharged from the oil tank 2 to the spare tank 4, and the frying oil 10 is injected from the spare tank 4 into the oil tank 2 after a certain time interval, the water contained in the frying oil 10 remains in the storage part of the spare tank 4, so that only the frying oil with the water removed can be injected from the spare tank 4 into the oil tank 2.

[0045] In particular, the fryer 1 of this embodiment utilizes a water-cooling jacket 22 to surround the lower oil tank 2b, thereby creating a structure that prevents the moisture released from the food into the frying oil 10 during frying from vaporizing and easily traps it in the lower oil tank 2b. Consequently, the frying oil discharged from the oil tank into the reserve tank contains a large amount of moisture. Therefore, if the moisture contained in the frying oil 10 can be retained in the accumulation section of the reserve tank 4 as described above, and only the frying oil with the moisture removed is injected from the reserve tank 4 into the oil tank 2, the moisture released from the food can be prevented from vaporizing in the oil tank 2 and actively collected in the reserve tank 4. As a result, the vaporization of moisture in the oil tank can be prevented and the deterioration of the frying oil due to oxidation can be prevented as much as possible, thereby extending the lifespan of the frying oil and reducing the cost of frying.

[0046] In addition, regarding the fine oil residue accumulated on the bottom plates 44a, 44b, and 44c of the spare tank 4, since the front end of the suction pipe is separated from the bottom plate 44c, these fine oil residues will not be injected into the oil tank along with the frying oil.

[0047] As explained above, according to the fryer 1 of the present invention, by temporarily draining the frying oil 10 used for frying cooking in the oil tank 2 into the spare tank 4 and then re-injecting it from the spare tank 4 into the oil tank 2, the moisture that has seeped into the frying oil 10 during frying cooking can be removed into the spare tank 4, thereby preventing the oxidative deterioration of the frying oil 10 during frying cooking as much as possible, extending the lifespan of the frying oil 10 until it needs to be replaced, and thus reducing the cost of frying cooking.

Claims

1. A deep fryer (1) that uses a heater (8) to heat frying oil (10) stored in an oil tank (2) and to fry food placed in the oil tank (2), the deep fryer (1) being characterized in that, The fryer (1) comprises: The upper oil tank (2a) is equipped with the heater (8) and is used for frying and cooking food. The lower oil tank (2b) is continuously arranged below the upper oil tank (2a) and has an outlet at its deepest part to discharge the oil residue generated in the oil tank (2) together with the frying oil (10), and has a plurality of inclined bottom plates (20) inclined toward the outlet. A water-cooling jacket (22) is provided around the lower oil tank (2b) and filled with cooling water to forcibly cool the frying oil in the lower oil tank (2b); Discharge valve (6), which opens and closes the discharge flow path (5) connected to the discharge outlet; The spare tank (4) stores the frying oil (10) flowing from the oil tank (2) through the discharge valve (6); and The return flow path (40) has an oil injection pump (41) and injects the frying oil (10) in the spare tank (4) into the lower oil tank (2b). The spare tank (4) has a filter (7) at the top to remove oil residue from the frying oil (10) flowing into the spare tank (4), and the bottom plate (44a, 44b) inside the spare tank (4) is inclined toward the deepest part of the frying oil accumulation section (45). A draw tube (46) communicating with the return flow path (40) is disposed in the storage section (45), and the front end of the draw tube (46) is disposed separately from the bottom plate (44c) of the spare tank (4).

2. The fryer according to claim 1, characterized in that, The spare tank (4) has casters (42) that allow it to be pulled out freely from under the oil tank (2), and the suction pipe (46) is removable from the spare tank (4).

3. The fryer according to claim 1, characterized in that, The filter (7) can be easily installed and removed from the spare tank (4).

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