JP6833197B2 - Joule heating device and Joule heating method - Google Patents

Description

The present invention relates to a Joule heating technique for energizing and heating while transporting a food material that gelatinizes when heated.

Continuous energization heating described in Patent Document 1 for energizing the food material while transporting the fluid food material to the flow path in the pipe to cook and heat the food material by Joule heat or to sterilize and heat the food material. An apparatus and a Joule heating apparatus described in Patent Document 2 have been developed. The continuous energization heating device for food materials includes a ring electrode type, an inner / outer electrode type, and a flat plate type. Patent Document 1 describes a ring electrode type and an inner / outer electrode type continuous energizing heating device, and Patent Document 2 describes a ring electrode type Joule heating device. Further, Patent Document 3 describes a flat plate type AC high electric field sterilizer.

The ring electrode type has a heating pipe formed by a plurality of annular electrodes and a plurality of cylindrical spacers made of an insulating material, and the annular electrodes adjacent to each other in the axial direction while flowing the food material through the food flow path in the heating pipe. A current is passed in the axial direction between the two, and the food material is energized and heated by Joule heat. In the ring electrode type, the resin cylindrical spacer forms a food flow path. The inner / outer electrode type has a heating pipe formed by a cylindrical outer electrode and a rod-shaped inner electrode arranged coaxially with the outer electrode inside the outer electrode, and is formed between the outer electrode and the inner electrode. While flowing the food material through the tubular food flow path, an electric current is passed between the outer electrode and the inner electrode in the radial direction, that is, the lateral direction, and the food material is energized and heated by Joule heat. Further, in the flat plate type, electrode plates are arranged on both sides of a resin plate-shaped spacer, and while the food material is passed through the food flow path formed by both electrode plates and the plate-shaped spacer, an electric current is applied between the opposing electrodes. The food material is energized and heated. Even in this flat plate type, the resin plate-shaped spacer forms a food flow path.

A device that heats the food material by Joule heat while flowing the food material through the food flow path in this way brings the food material into the food flow path as compared with the case where the food material is indirectly heated by hot water or steam. There is an advantage that the food material can be efficiently heated in a short time while flowing.

Japanese Unexamined Patent Publication No. 2001-169734 Japanese Unexamined Patent Publication No. 2015-156349 JP-A-2009-5583

Among foods, for example, custard cream is produced by heating a food material in which eggs, sugar, milk and the like are mixed. Flower paste is also produced by heating a food material that is a mixture of flour, cocoa and eggs and fats and oils. Such foods are mass-produced by heating to cooking temperature. When the food material after being heated to the cooking temperature is heated to the sterilization temperature, the food material is heated to a temperature higher than the cooking temperature.

Since custard cream and flower paste contain starch, the starch will gelatinize when heated to a cooking temperature of about 60 ° C. to 100 ° C. The gelatinization temperature differs depending on the content of starch contained in the food material and the like. When gelatinized, the viscosity becomes higher than before gelatinization.

For this reason, when a food material containing a large amount of starch, such as custard cream, which gelatinizes and becomes highly viscous when heated, is energized and heated using a heating pipe of a ring-shaped electrode, the tube wall on the inner peripheral surface of the heating pipe is heated. In the vicinity, the flow velocity of the food material is slower than in the vicinity of the center due to the influence of frictional resistance with the pipe wall. Therefore, the heating time of the food material near the tube wall is longer than that near the center, and the temperature of the food material near the tube wall becomes high. As a result, the food material near the tube wall is gelatinized first, and a hollow phenomenon occurs. When the hollow phenomenon occurs, the food material near the pipe wall is not extruded and adheres to the pipe wall to cause charring, and finally sparks occur in the heating pipe. In the ring type, a resin cylindrical spacer having a low thermal conductivity constitutes a food flow path, and the cylindrical spacer cannot be cooled.

In the Joule heating device described in Patent Document 2, a stirring shaft is provided inside the heating pipe, and the food material is stirred by the stirring blades provided on the stirring shaft. Since the pipe wall surface of the heating pipe is scraped off by the stirring blade, the food material is heated without stopping near the pipe wall surface. However, in the vicinity of the stirring blade and the stirring shaft, the flow velocity slows down along with the stirring blade and the stirring shaft as the viscosity of the food material increases, so that the food material adheres to the stirring blade and the stirring shaft and charring occurs. To do.

Since the flat plate type supplies a liquid food having a narrow food flow path and a low viscosity in a turbulent flow, it cannot be applied to heating a food material whose viscosity increases when heated. Moreover, the food material cannot be cooled by using a resin plate-shaped spacer as a cooling structure.

On the other hand, in the inner / outer electrode type Joule heating device provided with the cylindrical outer electrode and the rod-shaped inner electrode, a current flows between the inner electrode and the outer electrode in the radial direction, that is, in the direction across the direction in which the food material flows. Be swept away. Since the inner electrode is arranged inside the outer electrode on the outer peripheral surface of the rod-shaped inner electrode, the contact area with which the food material comes into contact is smaller than the inner peripheral surface of the cylindrical outer electrode. Therefore, the current density near the inner electrode is higher than that near the outer electrode. Further, the flow velocity of the food material in contact with the inner electrode and the outer electrode becomes slow due to frictional resistance. As a result, the food material near the inner side is burnt or sparked due to the influence of the current density and the flow velocity as compared with the food material near the outer electrode.

As described above, if the food material is burnt or sparked on the heating pipe, the gelatinized food material cannot be heated stably, and the food material is efficiently cooked and heated or sterilized and heated. You can't do it.

An object of the present invention is to stably and efficiently heat a food material that gelatinizes when heated.

Joule heating apparatus of the present invention, the food material to be gelatinized when heated to a Joule heating apparatus for energizing while transporting the food passage, and the outer electrode of cylindrical shape, arranged inside the outer electrode, wherein A rod-shaped inner electrode that has an energizing portion that faces the outer electrode in the radial direction and forms a food flow path through which the food material flows between the outer electrode, and power is supplied to the outer electrode and the inner electrode. An energizing unit that energizes the food material flowing through the food flow path in a direction that crosses the flow direction, a pipe that supplies a cooling liquid to the inner cooling flow path formed on the inner electrode, and an end portion of the energizing portion are provided. The food material in the vicinity of the inner electrode is cooled to a temperature lower than the gelatinization temperature, which has a tapered portion in which the distance between the energized portion and the outer electrode becomes longer toward the end face of the outer electrode. While heating the food material.

The Joule heating method of the present invention is a food formed between a cylindrical outer electrode and a rod-shaped inner electrode having a current-carrying portion that faces the outer electrode in the radial direction and arranged inside the outer electrode. A Joule heating method in which a food material that gelatinizes when heated is conveyed to the flow path and energized, and power is supplied to the outer electrode and the inner electrode to cross the flow direction to the food material flowing through the food flow path. When energized in the direction, the cooling liquid is supplied to the inner cooling flow path formed in the inner electrode, the cooling liquid is supplied to the outer cooling flow path formed in the outer electrode, and the food material in the vicinity of the inner electrode and The food material near the outer electrode is heated to a temperature lower than the gelatinization temperature, the food material near the center of the food flow path is heated to the gelatinization temperature, and the end portion of the energizing portion is the outer electrode. It has a tapered portion in which the distance between the energized portion and the outer electrode becomes longer toward the end face, and the current density flowing between the end face edge of the outer electrode and the inner electrode is lower than that of other portions. ..

The Joule heating device is an inner / outer electrode type that includes a cylindrical outer electrode and an inner electrode arranged inside the outer electrode, and a food flow path is formed between the outer electrode and the inner electrode. The inner peripheral surface of the outer electrode and the outer peripheral surface of the inner electrode face each other, the current-carrying area of the inner electrode is smaller than the current-carrying area of the outer electrode, and the area of the food material on the inner electrode side is the area on the outer electrode side. The current density is higher than that. When the current density is high, the temperature at which the food material is heated is higher than in the region where the current density is low, but by forming an inner cooling flow path in the inner electrode and supplying a coolant into the inner cooling flow path, the inner electrode The food material flowing in the vicinity is cooled to a temperature lower than that of the food material near the center of the food flow path. That is, the food material flowing through the food flow path is energized to heat the food material, and the food material near the inner electrode is cooled. As a result, the temperature at which the food material near the center in the cross section of the food flow path completes gelatinization first is reached, and the inner electrode is covered with the non-gelatinized food material. The non-gelatinized food material has a small frictional resistance with the inner electrode, the food material gelatinized in the central portion can be transported at a predetermined speed, and the food material can be heated stably and efficiently.

It is a vertical sectional view which shows the Joule heating apparatus. FIG. 1 is an enlarged cross-sectional view taken along the line AA in FIG. It is an enlarged sectional view of the outer electrode shown in FIG. It is the partially omitted enlarged sectional view of the inner electrode shown in FIG. FIG. 1 is an enlarged cross-sectional view of part B in FIG. 1, showing a coolant and a food material. It is a cross-sectional view of FIG. It is a cross-sectional view which conceptually shows the current density in the food material between the inner electrode and the outer electrode, and shows the same part as FIG. It is an enlarged sectional view which shows the entrance part of the food flow path among the inner electrode and the outer electrode. It is a block diagram which shows the control circuit of the Joule heating apparatus. It is a vertical cross-sectional view which shows the Joule heating apparatus which is a modification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The Joule heating device 10 shown in FIG. 1 can be used to energize a food material containing starch such as flower paste and gelatinized when heated from room temperature to a cooking temperature to heat it. The Joule heating device 10 has a cylindrical outer electrode 11, and the outer electrode 11 is made of a conductive material such as titanium. Spacers 13a and 13b made of an insulating material such as resin are abutted on both end surfaces of the outer electrode 11 via a seal packing 12. An inlet side lid member 14a made of an insulating material is abutted against the spacer 13a via a seal packing 15a, and an outlet side lid member 14b made of an insulating material is abutted against the spacer 13b via the seal packing 15b. Has been done. The heating pipes 16 that guide the food material are assembled by the spacers 13a and 13b and the lid members 14a and 14b arranged on both ends of the cylindrical outer electrode 11, and both ends of the heating pipe 16 are the lid members 14a and 14b. Is blocked by.

The lid member 14a on the inlet side is fixed to the fastening bracket 17a, the lid member 14b on the outlet side is fixed to the fastening bracket 17b, and both fastening brackets 17a and 17b have the same shape. Both fastening brackets 17a and 17b are fastened by four fastening rods 18. As shown in FIG. 2, the lower end portion of the fastening rod 18 penetrates the four corners of the fastening bracket 17a, and the fastening rod 18 penetrates the fastening bracket 17b. A nut 19a is screwed to the lower end of each fastening rod 18 in FIG. 1, and a nut 19b is screwed to the upper end. A fastening plate 21 to which the nut 19b is abutted is arranged at the upper end of the fastening rod 18, and a spring member 22 is mounted between the fastening plate 21 and the fastening bracket 17b. By adjusting the fastening amount of the nut 19b, the fastening force of the heating pipe 16 by the spring member 22 is adjusted.

Inside the outer electrode 11, a rod-shaped inner electrode 23 is arranged coaxially with the outer electrode 11, and the inner electrode 23 is formed of a conductive material such as titanium. The inner electrode 23 is longer than the heating pipe 16, and both ends of the inner electrode 23 penetrate the lid members 14a and 14b and project axially outward from the fastening brackets 17a and 17b. The lid members 14a and 14b are equipped with a sealing member (not shown) that seals between the inner electrode 23 and the lid members 14a and 14b. Nuts 24a and 24b for fixing the fastening brackets 17a and 17b to the inner electrode 23 are screwed to the protruding portion of the inner electrode 23.

A food flow path 25 through which the food material flows is formed between the heating pipe 16 and the inner electrode 23, and the food flow path 25 has a tubular shape. As described above, the heating pipe 16 has a tube-shaped food flow path 25 formed between the inner electrode 23 and the inner electrode 23, and the food flow path 25 is also formed between the inner electrode 23 and the outer electrode 11. There is. The lid member 14a is provided with a joint 26 on the inflow side, and the internal flow path of the joint 26 communicates with the food flow path 25. The lid member 14b is provided with a joint 27 on the outflow side, and the internal flow path of the joint 27 communicates with the food flow path 25. The inner diameters of the joints 26 and 27 on the inflow side and the outflow side are smaller than those of the food flow path 25, and the cross-sectional area of the portion of the lid members 14a and 14b through which the food material flows is larger than the cross-sectional area of the food flow path 25. It's getting smaller. Therefore, the flow velocity of the food material flowing from the joint 26 on the inflow side to the food flow path 25 via the lid member 14a becomes slow, and the flow velocity of the food material flowing out to the joint 27 on the outflow side through the lid member 14b becomes high. ..

A container 28 for accommodating food materials is arranged outside the Joule heating device 10, and the container 28 is connected to the joint 26 by a supply pipe 29. A pump 31 is provided in the supply pipe 29, and the food material in the container 28 is continuously conveyed and supplied to the food flow path 25 via the joint 26 by the pump 31. A discharge pipe 32 is connected to the joint 27, and the food material that has passed through the food flow path 25 is discharged to the outside of the Joule heating device 10 by the discharge pipe 32. The flow of the food material in the food flow path 25 is indicated by an arrow in FIG.

Feeding plugs 33a and 33b are attached to the inflow side end portion and the outflow side end portion of the outer electrode 11. On the other hand, power feeding plugs 34a and 34b are attached to the protruding ends on the inflow side and the protruding ends on the outflow side of the inner electrode 23. A power supply cable 35a is connected to the power supply plugs 33a and 33b of the outer electrode 11, a power supply cable 35b is connected to the power supply plugs 34a and 34b of the inner electrode 23, and the respective power supply cables 35a and 35b are connected to the power supply unit 36. To. A high frequency current of, for example, 20 kH is supplied from the energizing unit 36 to each power supply plug. Two feeding plugs 33a and 33b are attached to the outer electrodes 11, respectively, but only one of them may be used. Similarly, the inner electrode 23 is also provided with two feeding plugs 34a and 34b, but either one may be used.

When power is supplied from the energizing unit 36 to the outer electrode 11 and the inner electrode 23 while the food material is supplied to the food flow path 25, the food material flowing through the food flow path 25 is crossed in the flow direction. Current flows through. As a result, the food material is energized and heated as it flows between the outer electrode 11 and the inner electrode 23.

As shown in FIG. 3, the outer electrode 11 has an outer tube 37 and an inner tube 38 having a smaller diameter than the outer tube 37, and connecting rings 39a and 39b are provided at both ends of the outer tube 37. An outer cooling flow path 41 is formed inside in the axial direction. A coolant joint 42a on the inflow side is provided at the lower end of the outer electrode 11 in FIG. 3, and the internal flow path of the coolant joint 42a communicates with the outer cooling flow path 41. A coolant joint 42b on the outflow side is provided at the upper end of the outer electrode 11 in FIG. 3, and the internal flow path of the coolant joint 42b communicates with the outer cooling flow path 41. Therefore, the outer electrode 11 is cooled by the coolant flowing axially in the outer cooling flow path 41 from the coolant joint 42a toward the coolant joint 42a.

As shown in FIG. 4, the inner electrode 23 is formed of a hollow stepped bar, and an inner cooling flow path 43 is formed inside. The lower end of the inner electrode 23 in FIG. 4 is a coolant inflow portion 44a, and the upper end is a coolant outflow portion 44b. Therefore, the inner electrode 23 is cooled by the coolant flowing from the coolant inflow portion 44a toward the coolant outflow portion 44b.

The cooling liquid from the coolant tank 45 shown in FIG. 1 is circulated and supplied to the outer cooling flow path 41 and the inner cooling flow path 43. The coolant tank 45 is connected to the coolant inflow portion 44a of the inner electrode 23 by a pipe 46, and the coolant is supplied to the inner cooling flow path 43 from the inflow side of the food material. The coolant outflow portion 44b is connected to the coolant joint 42a of the outer electrode 11 by the circulation pipe 47, and the coolant that has passed through the inner cooling flow path 43 is supplied to the outer cooling flow path 41 from the inflow side of the food material. The coolant that has passed through the outer cooling flow path 41 is returned to the coolant tank 45 by the pipe 48. In this way, the cooling liquid in the cooling liquid tank 45 circulates in the continuously formed inner cooling flow path 43 and the outer cooling flow path 41. A heat exchanger (not shown) is incorporated in the coolant tank 45, and the coolant in the coolant tank 45 is held at a predetermined temperature and supplied to the Joule heating device 10 by a pump 49 provided in the pipe 46. To. However, as described above, the cooling liquid held at a predetermined temperature is supplied to the inner cooling flow path 43 and the outer cooling flow path 41 without circulating the cooling liquid in the coolant tank 45, and the outer cooling flow path is supplied. The coolant discharged from 41 may be discarded to the outside.

FIG. 1 shows a state in which no food material is supplied to the food flow path 25 and no coolant is supplied. 5 is an enlarged cross-sectional view of part B in FIG. 1, and FIG. 6 is a cross-sectional view of FIG. 5. In FIGS. 5 and 6, the coolant L and the food material W are shown.

The food material W contained in the container 28 is conveyed to the food flow path 25 between the outer electrode 11 and the inner electrode 23. On the other hand, the coolant L flows through the inner cooling flow path 43 formed inside the inner electrode 23 and the outer cooling flow path 41 formed inside the outer electrode 11.

FIG. 7 is a cross-sectional view conceptually showing the current density in the food material W between the inner electrode 23 and the outer electrode 11, and shows the same portion as in FIG.

As shown in FIG. 1, the Joule heating device 10 has a cylindrical outer electrode 11 and a rod-shaped inner electrode 23 arranged inside the cylindrical outer electrode 11, and is an inner / outer electrode type. In this type of Joule heating device 10, the energizing area of the outer peripheral surface of the inner electrode 23 is smaller than the energizing area of the inner peripheral surface of the outer electrode 11. Therefore, when a current flows through the food material W flowing in the food flow path 25 in a direction crossing the flow direction, the current density of the portion of the food material W in the region close to the inner electrode 23 becomes the outer side close to the outer electrode 11. It will be higher than the portion of the food material W in the region. The heating temperature of the food material W is higher in the region where the current density is high than in the region where the current density is low.

Therefore, when a food material containing a large amount of starch, such as custard cream, which is gelatinized and has a high viscosity when heated, is energized and heated by using an inner / outer electrode type Joule heating device 10 without cooling the inner electrode 23. Due to the frictional resistance between the food material and the inner electrode 23, the flow velocity in the vicinity of the inner electrode 23, that is, the portion on the inner peripheral surface side is slower than that in the radially outer portion, that is, the food material near the center. Therefore, the food material near the inner electrode 23 is charred or sparked due to the influence of the current density and the flow velocity.

On the other hand, as described above, when the cooling liquid is passed through the inner cooling flow path 43 inside the inner electrode 23 to cool the food material near the inner electrode, the food material is brought into the vicinity of the center of the food flow path 25. It can be cooled to a temperature lower than that of the food material, and the food material near the center can be gelatinized.

As shown in FIG. 4, the inner electrode 23 has an energizing portion 51 that faces the outer electrode 11 in the radial direction, and projecting portions 52a and 52b that project outward in the axial direction from both end faces of the outer electrode 11. doing. The protruding portions 52a and 52b have a smaller diameter than the energized portion 51 and are non-energized portions. Tapered portions 53a and 53b whose diameters gradually decrease toward the protruding portions 52a and 52b are provided at both ends of the energizing portion 51. The minimum diameter portions 54a and 54b of the tapered portions 53a and 53b are brought close to the inside of the end face of the outer electrode 11. When the minimum diameter portions 54a and 54b are positioned on the end faces of the outer electrode 11 in this way, the radial distance between the outer electrode 11 and the energized portion 51 of the inner electrode 23 becomes longer than the other portions. .. As a result, the distance between the minimum diameter portions 54a and 54b and the end face edges 55a and 55b of the outer electrode 11 is the longest than the other portions, and flows between the end face edges 55a and 55b and the inner electrode 23. The current value is smaller than the other parts.

FIG. 8 is an enlarged cross-sectional view showing an end portion of the outer electrode 11 on the food inflow side. In FIG. 8, the outer cooling flow path 41 and the inner cooling flow path 43 are not shown.

Since a large amount of current flows between the inner electrode 23 and the outer electrode 11 from the end face edge 55a of the outer electrode 11, the current density between the vicinity of the end face edge 55a and the inner electrode 23 is higher than that of the other parts. It is possible that it will be higher. On the other hand, when the tapered portion 53a of the inner electrode 23 is made to face the end face edge 55a in the radial direction, the current density flowing between the end face edge 55a and the inner electrode 23 can be made lower than other portions. As a result, the current density distributions of the inner electrode 23 and the outer electrode 11 in the axial direction can be made closer to each other more uniformly as a whole. This also applies to the end of the outer electrode 11 on the food outflow side. However, the outer diameter of the inner electrode 23 may be the same as a whole.

The Joule heating method for food materials by the Joule heating device 10 described above is executed as follows. A food material containing a large amount of starch, such as custard cream, which is heated to a cooking temperature and whose viscosity is higher than that before gelatinization, is contained in the container 28. The food material is supplied to the food flow path 25 in the heating pipe 16 by the pump 31, and the electric power supplied from the energizing unit 36 to the inner electrode 23 and the outer electrode 11 flows in the food material in the radial direction. The food material is energized and heated between the inner electrode 23 and the outer electrode 11 while going from the inlet to the outlet of the food flow path 25.

When power is supplied to the electrodes, as shown in FIG. 7, the current density of the food material W on the inner peripheral region side of the food flow path 25, that is, the inner region of the food material near the inner electrode 23, becomes the outer side. It is higher than the current density of the food material W on the outer region near the electrode 11, that is, on the outer peripheral surface side of the food flow path 25. However, since the inner electrode 23 and the outer electrode 11 are cooled by the coolant L, as shown in FIGS. 5 and 6, the food material Wi on the inner peripheral surface side and the food material Wo on the outer peripheral surface side are these. It is maintained at a temperature lower than that of the food materials Wa to Wc near the center of the space, that is, in the central region. In the food material near the center, the inner part in the radial direction is the highest, and the food material is gradually lowered toward the outer side in the radial direction. As shown in FIGS. 5 and 6, when the region near the center is divided into three regions for convenience as Wa to Wc, in these regions, the portion Wa in the radial direction to the portion outside in the radial direction. The heating temperature decreases toward Wc.

Therefore, in the food material flowing through the food flow path 25, the food materials Wa to Wc near the center are gelatinized first in a state where the food material Wi and the food material W are not gelatinized. As a result, the outer peripheral surface of the inner electrode 23 and the inner peripheral surface of the outer electrode 11 are covered with the non-gelatinized food materials Wi and Wo and flow through the food flow path 25. As a result, the food material W does not adhere to the electrodes, and the food material can be heated stably without causing charring or sparks.

The gelatinized food material is discharged to the outside from the joint 27 on the outflow side. As shown in FIG. 1, at the outflow end of the joint 27, a stirring portion 61 incorporating a stirring blade bent in a spiral shape is provided, and the food material flowing out from the joint 27 is stirred and discharged. It is guided to the hold portion (temperature holding portion) 62 by the pipe 32, and is held at the holding portion 62 for a predetermined time at the temperature after cooking. The food material held in the hold unit 62 for a predetermined time is cooled in the cooling unit 63 and supplied to a collection container (not shown).

As described above, the heating form of the food material W includes a form of heating to a cooking temperature at which the food material is gelatinized and a form of heating to a sterilization temperature higher than this after heating to the cooking temperature. .. When heating to the sterilization temperature, a sterilization heating device is connected to the discharge pipe 32, and the sterilized and heated food material is held at the holding temperature for a predetermined time and then cooled in the cooling unit. As the sterilization heating device, the Joule heating device 10 shown in FIG. 1 may be used.

The discharge pipe 32 is provided with a temperature sensor 65 for detecting the temperature of the food material discharged from the joint 27, and the voltage output from the energization unit 36 is controlled according to the detection temperature of the temperature sensor 65. Will be done. As a result, the cooking temperature, that is, the heating temperature of the food material is maintained at the set value. When a temperature sensor 66 for detecting the temperature of the coolant passing through the inner cooling flow path 43 is provided in the circulation pipe 47, the discharge flow rate of the coolant from the pump 49 can be controlled according to the temperature of the coolant. it can.

FIG. 9 is a block diagram showing a control circuit of the Joule heating device 10, and the control unit 67 includes a temperature sensor 65 for detecting the temperature of the food material and a temperature sensor 66 for detecting the temperature of the coolant. Detection signal is sent. The output voltage of the energizing unit 36 is adjusted based on the detection signal of the temperature sensor 65. Further, the discharge amount of the pump 49 is adjusted based on the detection signal of the temperature sensor 66.

FIG. 10 is a vertical cross-sectional view showing a Joule heating device 10 which is a modified example. In this Joule heating device 10, the piping 71 for supplying the cooling liquid to the outer cooling flow path 41 and the inner cooling flow path 43 are cooled. The piping 72 that supplies the liquid is a separate system. As shown in FIG. 10, the coolant in the coolant tank 45a is supplied to the cooling flow path 41 outside the pump 49a provided in the pipe 71. On the other hand, the coolant in the coolant tank 45b is supplied to the inner cooling flow path 43 from the pump 49b provided in the pipe 72. In this way, if the piping for supplying the cooling liquid is a separate system, the temperatures of the outer electrode 11 and the inner electrode 23 can be adjusted separately. The discharge amount of each of the pumps 49a and 49b is controlled by the control unit 67 based on the detection signal detected by the temperature sensors 66a and 66b for the temperature of the coolant.

Each of the above-mentioned Joule heating devices 10 has a form in which cooling flow paths are formed in both the outer electrode 11 and the inner electrode 23, but depending on the type of food material, a cooling flow path is provided only in the inner electrode 23 and is provided on the outer side. The electrode 11 may be in a form in which a cooling flow path is not provided. In FIG. 10, the container 28, the energizing unit 36, and the like shown in FIG. 1 are omitted.

As shown in FIG. 10, the cooling method of the Joule heating device 10 includes a form in which the inner cooling flow path 43 and the outer cooling flow path 41 are supplied with a cooling liquid by piping of different systems, and as shown in FIG. In addition, there is a form in which the cooling liquid is supplied by one continuous system of piping, and a form in which the cooling liquid is supplied only to the inner cooling flow path 43. As described above, the temperature control method for the food material includes a form in which the output voltage of the energizing unit 36 is adjusted, a form in which the flow velocity of the coolant, that is, a flow rate is adjusted, and a form in which both are adjusted. Each form can be appropriately selected depending on the type of food material.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist thereof. This Joule heating device can be applied to foods whose viscosity does not change with temperature, but is suitable for energization heating of food materials that gelatinize when heated.

10 Joule heating device 11 Outer electrodes 14a, 14b Lid member 16 Heating pipe 18 Fastening rod 23 Inner electrode 25 Food flow path 28 Container 29 Supply pipe 32 Discharge pipe 33a, 33b Power supply plug 34a, 34b Power supply plug 35a, 35b Power supply cable 36 Energization Unit 41 Outer cooling flow path 43 Inner cooling flow path 45, 45a, 45b Coolant tank 46 Piping 47 Circulation piping 48 Piping 49, 49a, 49b Pump 51 Energizing part 52a, 52b Protruding part 53a, 53b Tapered part 55a, 55a End face edge

Claims (6)

A Joule heating device that energizes food materials that gelatinize when heated while transporting them into the food flow path.
Cylindrical outer electrode and
A rod-shaped inner electrode that is arranged inside the outer electrode, has an energizing portion that faces the outer electrode in the radial direction, and forms a food flow path through which the food material flows between the outer electrode and the outer electrode.
An energizing unit that supplies electric power to the outer electrode and the inner electrode and energizes the food material flowing through the food flow path in a direction crossing the flow direction.
A pipe that supplies the cooling liquid to the inner cooling flow path formed in the inner electrode, and
A tapered portion provided at the end of the energizing portion and in which the distance between the energizing portion and the outer electrode becomes longer toward the end surface of the outer electrode.
A Joule heating device that heats a food material while cooling the food material in the vicinity of the inner electrode to a temperature lower than the gelatinization temperature. In Joule heating device according to claim 1, have a pipe for supplying cooling liquid to the outer cooling channel formed in the outer electrode, cool the food material in the vicinity of the outer electrode to a temperature below the gelatinization temperature A Joule heating device that heats food materials while heating. The Joule heating device according to claim 2 has a circulation pipe for supplying the cooling liquid flowing out from the inner cooling flow path to the outer cooling flow path, and the inner cooling flow path and the outer cooling flow path are continuous. Joule heating device as a flow path. In Joule heating apparatus according to claim 1, wherein the inner electrode, the front have a diameter of the protrusion than the conducting portion projecting axially outward of the end faces of the Kisotogawa electrode A Joule heating device in which the tapered portion has a smaller diameter toward the protruding portion. The Joule heating device according to any one of claims 1 to 4, wherein the tapered portions are provided at both ends of the current-carrying portion . When heated, the food flow path formed between the cylindrical outer electrode and the rod-shaped inner electrode having a current-carrying portion that faces the outer electrode in the radial direction and arranged inside the outer electrode is gelatinized. This is a Joule heating method that energizes the food material while transporting it.
Electric power is supplied to the outer electrode and the inner electrode to energize the food material flowing through the food flow path in a direction crossing the flow direction.
A cooling liquid is supplied to the inner cooling flow path formed in the inner electrode, and the cooling liquid is supplied.
A cooling liquid is supplied to the outer cooling flow path formed on the outer electrode, and the cooling liquid is supplied.
The food material near the inner electrode and the food material near the outer electrode are heated to a temperature lower than the gelatinization temperature, and the food material near the center of the food flow path is heated to the gelatinization temperature.
The end portion of the current-carrying portion has a tapered portion in which the distance between the current-carrying portion and the outer electrode becomes longer toward the end face of the outer electrode, and is between the end face edge of the outer electrode and the inner electrode. Joule heating method that lowers the current density flowing through the electrode than other parts.

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