flyer

Abstract

To form a substantially uniform electric field between an upper conveyor 10 and a lower conveyor 20.SOLUTION: A fryer includes; an upper conveyor 10 and a lower conveyor 20 which are arranged at two vertical stages in an oil tank 31; and a power unit 32 for applying a voltage V to the upper conveyor 10. The power unit 32 allows a lower surface side of a conductive conveyor net 12 of the upper conveyor 10 to be an electrode for forming an electric field, so as to form an electric field with an upper surface of a conductive conveyor net 22 of the lower conveyor 20.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This invention relates to a continuous fryer equipped with two net conveyors, one above the other. [Background technology]

[0002] In commercial fryers, applying an electric field to the oil used for frying or to the food being fried is said to have the effect of preventing the oil from deteriorating and improving the taste of processed foods.

[0003] Therefore, in order to apply such technology to continuous fryers, it has been proposed to place flat electrodes for applying voltage in the gap between the left and right sides of two upper and lower net conveyors installed in an oil tank and the inner surface of each side wall of the oil tank (Patent Document 1), or to place frame-shaped electrodes for applying voltage inside each of the upper and lower net conveyors, parallel to each conveyor net (Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Utility Model Registration No. 3165708

[0005] [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-95695 Summary of the Invention [Problem to be solved by the invention]

[0006] In the former case of the prior art, the electric field in the oil is concentrated between the electrode for applying voltage and the side edges of the upper and lower net conveyors, while in the latter case, it is concentrated between the electrode for applying voltage and the conveyor net of each net conveyor. As a result, in either case, the necessary electric field is hardly formed between the upper and lower net conveyors through which the workpieces are transported, and sufficient effect cannot be expected. In addition, the electrodes installed in the oil tank themselves may get in the way during cleaning work or may hinder the flow of oil in the oil tank.

[0007] Therefore, in view of the problems of the prior art, the object of this invention is to provide a flyer that can apply voltage directly to the upper conveyor, thereby eliminating the need for an electrode for applying voltage and forming a substantially uniform electric field between the upper and lower net conveyors on which the workpieces are transported. [Means for solving the problem]

[0008] To achieve this object, the present invention is configured to include an oil tank, an upper conveyor and a lower conveyor installed in two tiers, one above the other, within the oil tank, and a power supply unit that applies voltage to the upper conveyor. The upper and lower conveyors are net conveyors each having an endless conductive conveyor net, and the power supply unit uses the underside of the conveyor net of the upper conveyor as an electrode for forming an electric field, forming an electric field between the upper surface of the conveyor net of the lower conveyor, while the lower conveyor and the oil tank are grounded together with the housing of the power supply unit.

[0010] The upper and lower conveyors may be arranged so that the lower and upper surfaces of the respective conveyor nets face each other vertically. [Effects of the Invention]

[0011] With this configuration, by applying a voltage to the upper conveyor, the power supply unit can form a nearly uniform electric field in the oil between the lower surface of the conveyor net of the upper conveyor and the upper surface of the conveyor net of the lower conveyor, which face each other above and below, i.e., between the upper and lower net conveyors through which the workpieces are transported, and can be expected to have a good electric field application effect on both the oil for frying and the workpieces being fried.In addition, because the lower surface of the conveyor net of the upper conveyor can be used as an electrode for applying a voltage and forming an electric field, there is no need to install any other special electrodes in the oil tank, and there is no risk of inconvenience caused by installing electrodes in the oil tank.

[0012] The upper conveyor can be easily insulated from the lower conveyor and the oil tank it is installed in by installing it on the frame of the lower conveyor via an insulating support material. The support material can be formed in any shape, such as a long material that is continuous in the front-to-rear direction of the upper and lower conveyors, or a block material with multiple pieces dispersed in the same direction, as long as it allows the frame of the upper conveyor to be installed on the frame of the lower conveyor via the support material.

[0013] The upper conveyor combined with the lifting mechanism can be lifted higher by the lifting mechanism as needed, which is convenient for cleaning work, etc. The insulating lifting tool can maintain insulation between the upper conveyor and the lifting mechanism regardless of the lifting height of the upper conveyor.

[0014] If the drive motor for the upper conveyor is insulated from the upper conveyor and mounted on the frame of the upper conveyor, there is no risk of the insulation of the upper conveyor being impaired even if the casing of the drive motor itself is grounded for safety. In this case, the drive motor can be connected to the shaft for the drive sprocket of the upper conveyor via an insulating coupling, for example, to complete the insulation from the upper conveyor. [Brief explanation of the drawings]

[0015] [Figure 1] Overall configuration schematic vertical cross-sectional view [Figure 2]Schematic cross-sectional view of Figure 1 taken along line XX [Figure 3] Overall configuration schematic side view [Figure 4] Operation explanation diagram [Figure 5] An explanatory diagram equivalent to FIG. 2 showing a comparative example DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the invention will be described with reference to the drawings.

[0017] The fryer comprises an oil tank 31, an upper conveyor 10, a lower conveyor 20, and a power supply 32 (Figs. 1 and 2). The upper conveyor 10 and the lower conveyor 20 are installed in two levels, one above the other, inside the oil tank 31, and the power supply 32 can apply a voltage V to the upper conveyor 10 via an output cable 32a.

[0018] The oil tank 31 is a long box-shaped container, and the oil F for frying stored therein can be heated to a predetermined temperature by a heat source such as a burner or heater (not shown). The bottom of the oil tank 31 has a gently sloping upward slope 31a at the front.

[0019] The upper conveyor 10 is a net conveyor configured by incorporating an endless conductive conveyor net 12, for example made of metal, between left and right frames 11, 11 so that it can circulate. The front of the upper conveyor 10 is formed obliquely upward following the slope 31a at the front of the oil tank 31, and the conveyor net 12 is wound around a plurality of rollers 13, 13... on front and rear shafts 13a, 13a between the frames 11, 11. Note that a guide roller (not shown) is provided in the middle of the upper conveyor 10.

[0020] The shaft 13a of the rollers 13, 13... at the front of the upper conveyor 10 is connected to a drive sprocket 13c via a drive chain 13b, and the shaft 13d of the drive sprocket 13c is connected to the output shaft 14a of a drive motor 14 via an insulating coupling 14b. The drive motor 14 is mounted on the frames 11, 11 of the upper conveyor 10, insulated from the upper conveyor 10 via a bracket (not shown). The drive motor 14 is a variable-speed motor controlled by a control device (not shown), and can drive the upper conveyor 10 in the direction of arrow K1 in Figure 1. The casing of the drive motor 14 is grounded for safety.

[0021] The lower conveyor 20 is a net conveyor configured by incorporating an endless conductive conveyor net 22 made of, for example, metal between left and right frames 21, 21 so as to be able to circulate. The front part of the lower conveyor 20 is formed obliquely upward following the slope 31a at the front part of the oil vat 31 and protrudes to the front end of the oil vat 31, and the conveyor net 22 is wound around a plurality of rollers 23, 23... on front and rear shafts 23a, 23a between the frames 21, 21. Note that a guide roller (not shown) is provided in the middle part of the lower conveyor 20.

[0022] The shafts 23a of the rollers 23, 23... at the front of the lower conveyor 20 are connected via drive chains 23b to sprockets 24b on the output shaft 24a of a drive motor 24, which is mounted on the frames 21, 21 of the lower conveyor 20 via brackets (not shown). The drive motor 24 is a variable-speed motor controlled by a control device (not shown), and can drive the lower conveyor 20 in the direction of arrow K2 in Figure 1. The rear of the lower conveyor 20 extends along the bottom of the oil tank 31, beyond the rear end of the upper conveyor 10.

[0023] The frames 21, 21 of the lower conveyor 20 are installed on the bottom surface of the oil tank 31. The frames 11, 11 of the upper conveyor 10 are installed on the frames 21, 21 of the lower conveyor 20 via insulating supports 25, 25 on the left and right, and the entire upper conveyor 10, except for the drive motor 14, is insulated from the oil tank 31 and the lower conveyor 20.

[0024] The upper conveyor 10 and the lower conveyor 20 transport the workpieces W, W... that are placed at the rear of the oil vat 31 via their respective upper and lower surfaces while they remain submerged in the heated oil F in the oil vat 31, and can be fried before they reach the front end of the oil vat 31. The workpieces W, W... are continuously placed onto the conveyor net 22 of the lower conveyor 20 at the rear of the oil vat 31 (in the direction of arrow K in Figure 1), and are discharged to the front of the oil vat 31 via the upward inclined portion of the lower conveyor 20 at the front end of the oil vat 31. However, in Figure 1, the frames 11, 21 of the upper conveyor 10 and the lower conveyor 20 are not shown.

[0025] The upper conveyor 10 is suspended so as to be able to rise and fall via a lifting mechanism 40 (FIGS. 2 and 3). However, in FIG. 3, the frames 11, 21 and drive motors 14, 24 of the upper conveyor 10 and the lower conveyor 20 are not shown.

[0026] The lifting mechanism 40 is composed of front, rear, left, and right wires 42, 42... that suspend the upper conveyor 10 via insulating suspenders 41. The upper end of each wire 42 is wound around a hoist drum 43, and each pair of front and rear hoist drums 43, 43... is fixed to a common drive shaft 43a. The front and rear drive shafts 43a, 43a are arranged to cross the upper conveyor 10 via frame frames 44, 44 with legs 44a, 44a erected on the left and right side edges of the oil vat 31, and can be rotated forward and backward synchronously via a common variable speed motor (not shown).

[0027] Therefore, the upper conveyor 10 can be lifted up above the left and right support materials 25, 25 while maintaining a horizontal position by simultaneously rotating the hoist drums 43, 43... forward and backward via the drive shafts 43a, 43a to wind up and lower the front, rear, left and right wires 42, 42..., and can then be lowered onto the support materials 25, 25. Furthermore, if the lifting mechanism 40 is used to integrally connect the frames 11, 11 of the upper conveyor 10 to the support materials 25, 25 via, for example, an engagement bracket (not shown), the upper conveyor 10 and the lower conveyor 20 can be lifted up and down all at once, which can be conveniently used when cleaning the upper conveyor 10, the lower conveyor 20 and the oil tank 31, respectively.

[0028] The output cable 32a of the power supply unit 32 is connected to the frame 11 of the upper conveyor 10 (FIG. 2). However, regardless of the illustration, the output cable 32a has a sufficient slack length to accommodate the lifting and lowering operation of the upper conveyor 10, and may be configured to be able to disconnect from the upper conveyor 10 via a connector (not shown) as necessary.

[0029] The output specifications of power supply device 32 are preferably within the following ranges, for example: positive or negative DC output, or AC output with a frequency of 20 kHz or less, including commercial frequencies, with a voltage V of approximately 0.2 to 20 kV. Furthermore, power supply device 32 is preferably equipped with a current limiting circuit that limits the output current to, for example, 5 mA or less, or a current monitoring circuit that instantly shuts off the output current when the output current increases by, for example, 5 mA or more, to prevent electric shock accidents to workers.

[0030] The fryer operates the upper and lower conveyors 10 and 20 at the same speed to continuously fry the workpieces W, W.... When a voltage V is applied to the upper conveyor 10 by the power supply 32, a nearly uniform electric field is formed between the underside of the conveyor net 12 of the upper conveyor 10 and the upper side of the conveyor net 22 of the lower conveyor 20, i.e., in the oil F through which the workpieces W, W... are transported (curve (1) in Figure 4). The horizontal axis of Figure 4 indicates the widthwise position of the upper and lower conveyors 10 and 20 in Figure 2, while the vertical axis indicates the relative strength of the electric field between the conveyor nets 12 and 22. The upper conveyor 10 is insulated from the lower conveyor 20, oil tank 31, and lifting mechanism 40. The lower conveyor 20 and oil tank 31 are grounded, along with the casing of the drive motor 14 and the housing of the power supply 32.

[0031] Incidentally, curves (2) and (3) in Figure 4 represent comparative data for a case in which electrodes P for applying voltage are arranged in the oil tank 31 according to Figures 5(A) and 5(B), respectively. In Figure 5(A), flat electrodes P, P are arranged between the left and right sides of the uninsulated upper and lower conveyors 10 and 20 and the inner surface of each side wall of the oil tank 31, via insulating supports 25, 25. A voltage V of the same polarity is applied to each electrode P via output cables 32a, 32a from a power supply 32. In Figure 5(B), flat electrodes P are arranged in an insulated manner inside the conveyor net 22 of the lower conveyor 20, and a voltage V is applied to the electrode P via output cable 32a from the power supply 32. Note that the power supply 32 is not shown in Figures 5(A) and 5(B).

[0032] With the configuration of Figure 5(A), the electric field between the conveyor nets 12 and 22 is extremely concentrated at the left and right side edges of the upper conveyor 10 and the lower conveyor 20 (curve (2) in Figure 4). With the configuration of Figure 5(B), the electric field is uniformly distributed across the width of the upper conveyor 10 and the lower conveyor 20 (curve (3) in Figure 4), but its strength is only about one-fifth of that of the present invention, as shown by curve (1) in the same figure. However, in Figure 4, the absolute value of the electric field strength depends on the voltage V from the power supply 32, so voltage V can be set appropriately as needed.

[0033] The approximate specifications of the upper conveyor 10 and the lower conveyor 20 when curves (1) to (3) in Figure 4 were obtained are as follows: the width of the upper and lower conveyor nets 12 and 22 is 600 mm, the distance between their upper and lower sides is 40 mm, and the distance between the lower side of the conveyor net 12 and the upper side of the conveyor net 22 is 55 mm. Also, each electrode P in Figure 5(A) is a SUS430 plate with a vertical width of 15 mm, a front-to-back length of 700 mm, and a thickness of 1 mm, and the electrode P in Figure 5(B) is a SUS430 plate with a width length of 590 mm, a front-to-back length of 400 mm, and a thickness of 1 mm, and is a distance of 8 mm from the upper side of the conveyor net 22.

[0034] In the above description, the upper conveyor 10 is insulated from the lower conveyor 20, oil tank 31, and lifting mechanism 40 via insulating support materials 25, 25, suspenders 41, 41... in order to apply voltage V from the power supply 32 to operate the conveyor net 12 as an electrode for generating an electric field, and further, in order to ground the casing of the drive motor 14 to enhance safety, the drive motor 14 is insulated and mounted on the frames 11, 11, and an insulating coupling 14b is introduced. Therefore, the specific insulating support structure of the upper conveyor 10 may be further modified as desired as long as the same operating function can be achieved. [Industrial Applicability]

[0035] The present invention can be widely and suitably applied to large and small commercial fryers for food processing that are equipped with upper and lower two-tier net conveyors. [Explanation of symbols]

[0036] V...Voltage 10...Upper conveyor 12...Conveyor net 20...Lower conveyor 22...Conveyor net 31...Oil tank 32...Power supply device Patent applicant: Asahi Sosetsu Co., Ltd.

Claims

1. A fryer comprising an oil tank, an upper conveyor and a lower conveyor installed in two tiers, one above the other, within the oil tank, and a power supply unit that applies voltage to the upper conveyor, wherein the upper and lower conveyors are net conveyors each having an endless conductive conveyor net, and the power supply unit uses the underside of the conveyor net of the upper conveyor as an electrode for forming an electric field, forming an electric field between the lower conveyor and the upper surface of the conveyor net of the lower conveyor, while the lower conveyor and the oil tank are grounded together with the housing of the power supply unit.

2. 2. The flyer according to claim 1, wherein the upper and lower conveyors have upper and lower surfaces of the conveyor nets facing each other.

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