JP2002017568A - Heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the yield of fluid food and drink. SOLUTION: The fluid food and drink fed into a hopper 11 passes through a pipe in a heating unit 12 by a pump 14, and the food and drink is heated by joule heat by energizing to an electrode provided at the pipe. Corresponding to the temperature of the food and drink having passed through the unit 12, whether heating operation is in a starting state, a restarting state or a steady state is judged and a heating mode is set to a quickly heating mode or a PID control mode. The quantity of the food and drink in a housing tank 16 is detected by a level sensor 34 and the food and drink is heated by an energizing condition corresponding to a housing quantity to the electrode from a power supplying part 32 in accordance with a signal from this sensor 34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating apparatus for heating food and drink having fluidity.

[0002]

2. Description of the Related Art For heating low-viscosity foods and drinks such as juices and soups, and high-viscosity foods and drinks such as highly viscous pasty foods such as pudding and jelly, for example, a heating method is used. As disclosed in Japanese Unexamined Patent Publication No. Hei 7-39320 and Japanese Unexamined Patent Publication No. Hei 7-250760, a technique has been developed in which a food or beverage itself is energized and heated by Joule heat.

[0003] In the case of heating a food having fluidity by Joule heat, the food is heated while flowing the food through the heating pipe using a heating pipe having electrodes arranged at predetermined intervals. In order to continuously supply food and drink into the heating pipe, the food and drink are taken out of the hopper by the pump and fed into the heating pipe.

In order to set food to a desired temperature in a heating pipe, the temperature of the food is detected, and feedback control is performed so as to change the voltage value in accordance with the detected temperature. The relationship between the temperature and the control operation includes P which is a combination of the proportional operation, the integral operation, and the differential operation.
PID control for performing an ID operation is employed.

[0005] On the other hand, depending on the type of food and drink, the food and drink after being heated by the heating pipe is carried into the storage tank, and is automatically filled into the product packaging material such as a container or a bag from the storage tank. There are cases. In this case, the packaging material filled with food and drink is transported by the transport device to a later process such as a packaging process.

[0006]

However, if the processing in the step after heating by the heating pipe including the step of filling food and drink into the packaging material is not performed smoothly, or if a problem or trouble occurs, the It is necessary to stop the heating operation, and restart the heating operation after troubles and defects are avoided.

When the heating operation is restarted or when the heating operation is started, that is, when the heating operation is started, the food may be discharged from the heating pipe without being heated to a predetermined temperature. The reason for this is that the heating temperature control by the PID control described above is set based on a state where the heating operation condition is in a steady state, so that a predetermined energizing time is not secured at the time of starting or restarting the heating operation. In some cases, the fuel is discharged from the heating pipe without being heated to the set temperature.

For this reason, the temperature of the food or drink after heating must be measured, and the food or drink not heated to a predetermined temperature must be discarded. Thus, not only at the start of the heating operation, that is, at the start of the start of the heating device, such as at the start of the first work in the morning, the heating operation is performed under the condition that the heating device is operating. Frequent stoppages and frequent restart operations increase the amount of food and beverage that must be discarded, reducing the yield of heated products.

[0009] Further, if the filling operation of the packaging material such as a container or bag for packaging is not performed from the storage tank at a predetermined timing, the heated food and drink in the storage tank for a relatively long time. Will stay. Depending on the type of food and drink, if the time spent in the storage tank after heating exceeds about 15 minutes, it may not be possible to commercialize the product. Since the roughness is not obtained, the yield of the heated product is reduced.

[0010] An object of the present invention is to improve the product yield by enabling food and drink to be heated to a desired temperature in a short time even at the start and restart of the heating operation.

Another object of the present invention is to improve the product yield by preventing food and drink from staying in the storage tank for a long time by changing the heating condition according to the amount of food and drink in the storage tank. is there.

[0012]

SUMMARY OF THE INVENTION A heating device according to the present invention is a heating device for heating a food or drink having fluidity as an object to be heated by Joule heat, and is provided with electrodes and guides the object to be heated. A pipe, a temperature sensor for detecting the temperature of the object to be heated, a power supply unit for supplying power to the electrode, and a heating operation in a start-up state or a restart state based on a signal from the temperature sensor. Operating state determining means for determining whether the operating state is in a steady state, and when the operating state determining means determines that the operating state is in the startup state or the restart state, the power supply unit is controlled in a rapid heating mode, Control means for controlling the power supply unit in the PID control mode when it is determined that the state is the state.

[0013] The heating device of the present invention is a heating device for heating a food or beverage having fluidity as an object to be heated by Joule heat, wherein the tube is provided with electrodes and guides the object to be heated. A storage tank for storing a predetermined amount of the object to be heated after completion of the heating by the passage, a level sensor for detecting an amount of the object to be heated in the storage tank, a power supply unit for supplying power to the electrodes, Storage means for storing the relationship between the flow rate of the object to be heated flowing inside and the energizing conditions supplied to the electrodes; and reading the energizing conditions from the storage means based on a signal from the level sensor. Control means for sending a control signal to the power supply unit so as to supply power to the electrodes. The energization conditions are set in a plurality of steps or steplessly in accordance with a signal from the level sensor.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a view showing a heating device according to an embodiment of the present invention. The heating device heats the food and the hopper 11 for accommodating the fluid food or drink to be heated. And a heating unit 12. Hopper 1
The object to be heated in 1 is supplied into the heating unit 12 by a pump 14 provided in a flow path 13 connecting the discharge port of the hopper 11 and the inflow port of the heating unit 12. The heating unit 12 is arranged to be inclined in the vertical direction, the lower side is an inflow port, the upper side is an outflow port, and the food and drink after the heat treatment are accommodated by a guide pipe 15 provided at the upper end of the heating unit 12. It is supplied to the tank 16.

The storage tank 16 stores a predetermined amount of food and drink, and discharges the food from a discharge nozzle 17 provided at the lower end. The guide pipe 15 is provided with a flow path switching valve 18. The flow path switching valve 18 opens and closes the flow path to supply the food heated by the heating unit 12 to the storage tank 16, and a disposal position. It operates to a disposal position where food and drink are discharged from the mouth 19.

A transfer device 22 for transferring the container 21 is disposed below the discharge nozzle 17. The transfer device 22 mounted on the upstream side of the transfer device 22 and transferred to a position directly below the storage tank 16 discharges the container 21. A predetermined amount of food and drink is injected from the nozzle 17.

A lid mounting device (not shown) is provided on the downstream side of the transport device 22 or in the next step of the transport device 22, and a lid is mounted on the container 21 into which a predetermined amount of food is poured. Become. In addition, container of food is stored in container 2
Instead of 1, another packaging material such as a bag may be used, and the food may be injected therein.

FIG. 2A is a partially cutaway perspective view showing a part of the heating unit 12 in an enlarged scale, and a heating pipe 24 is incorporated in a tubular reinforcing member 23. .
The conduit 24 is formed by alternately attaching cylindrical spacers 25 made of an insulating material such as resin and ring-shaped electrodes 26 so that food and drink are guided and conveyed in the conduit 24. The two electrodes 26 adjacent to each other in the direction in which the food flows are mutually electrode pairs.

The shape of the spacer 25 may be a rectangular cylinder, or a cylinder having a circular inner peripheral surface and a rectangular outer peripheral surface may be used. The shape also corresponds to the cross-sectional shape of the spacer 25. A seal material 27 is incorporated between the spacer 25 and the electrode 26 to prevent food and drink from leaking out of the conduit 24.

As disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 7-39320, each ring-shaped electrode 26 is provided with a cavity or flow path for cooling liquid circulation, and the electrode 2 is formed by the cooling liquid.
6 may be cooled.

FIG. 2B is a partially cutaway perspective view showing an enlarged part of a modification of the heating unit 12. In this case, the pipe 24 has a rectangular cross section, and the flow in the pipe 24 is changed. The path is surrounded by four wall surfaces, and is entirely formed of an insulating material such as a synthetic resin. A pair of plate-like electrodes 26 are formed on the mutually facing inner wall surfaces of the conduit 24.
Are arranged, and a plurality of pairs of electrodes 26 are arranged at predetermined intervals in the direction in which the food flows.

FIG. 3 is a sectional view showing the entirety of the conduit 24 incorporated in the reinforcing member 23 of the heating unit 12, and the conduit 24 has the shape shown in FIG. This conduit 24 has six cylindrical spacers 25 and seven ring-shaped electrodes 26, and joints 28 a, 2 at both ends.
8b is attached.

The joint 28a is on the inflow side of the pipe 24, and the joint 28b is on the outflow side, and the food or the food to be heated flows in the pipe 24 in the direction indicated by the arrow. Although the conduit 24 is arranged inclined as described above, it is shown in FIG. 3 as being horizontal for convenience.
However, the pipeline 24 may be arranged in the vertical direction or the horizontal direction. Further, the heating unit 12 may be formed by connecting a plurality of pairs of pipes 24.

FIG. 4 is a block diagram showing a control circuit for controlling the operation of the heating device shown in FIG. 1. Power is supplied from a control unit 31 as control means to supply power to each electrode 26. A control signal is sent to the unit 32. The power supply unit 32 includes a DC generation unit that converts a commercial power supply into a DC current, a high-frequency generation unit that generates a high-frequency current from the DC current, a high-frequency transformer, and the like. Further, the operation of the pump 14 and the operation of the flow path switching valve 18 are controlled by a control signal from the control unit 31.

A temperature sensor 33 is provided in the duct of the heating unit 12, and a level sensor 34 for detecting the amount of food and drink supplied to the inside of the storage tank 16 is provided. A flow rate sensor 35 is provided at a predetermined position such as the pump 14 and the flow path 13 to detect the flow rate of the food flowing through the inside. Detection signals from the temperature sensor 33, the level sensor 34, and the flow rate sensor 35 are sent to the control unit 31.

The control unit 31 has an operation status judging section 36. The operation status judging section 36 determines, based on a signal from the temperature sensor 33, whether the heating operation is in a start-up state, a restart state, or a steady state. Determine if it is in the state. When it is determined that the heating operation is in the start-up state or the restart state, the rapid heating mode is set, and the power supply to the power supply unit 32 is controlled in the rapid heating mode, and it is determined that the heating operation is in the steady state. PI
The D control mode is set, and the energization control for the power supply unit 32 is performed in the PID control mode.

FIG. 5 is a diagram showing the control conditions of the rapid heating mode and the PID control mode, in which the temperature of the food after heating, that is, the output temperature detected by the temperature sensor 33 is lower than the steady state temperature Ta. Is set to the rapid heating mode, and when the temperature is lower than the steady state temperature Ta, the PID control mode is set.

In FIG. 5, the two-dot chain line A indicates the power supply control to the electrodes from the start-up or restart of the heating operation.
It shows a change in the temperature of food and drink when ID control is performed,
One-dot chain line M ₁ indicates the temperature variation in the case of the rapid heating mode, the solid line M ₂ shows the temperature change in the case of the PID control mode if it exceeds the steady state temperature Ta by rapid heating mode.

In the PID mode, if there is a difference between the set temperature Tb and the output temperature based on a signal from the temperature sensor 33, the voltage is controlled in proportion to the difference. In the proportional operation, the proportional deviation e and the output m are given by m = K ·
e + m ₀ , where K is a proportional gain,
m ₀ is the manipulated variable when the deviation is zero, and the reciprocal of the proportional gain when m and m ₀ are expressed as a percentage of the entire output change range is called a proportional band and is expressed in%. In the illustrated heating device, the proportional gain K is set so that the proportional band becomes 70%, and the voltage to the electrodes is controlled in a range of about 70%.

If the heating temperature is controlled only by PID control without performing rapid heating, the deviation in the steady state must be within a predetermined range in consideration of the heat capacity of food and drink. It takes tb time to reach Tb. On the other hand, when the heating temperature is equal to or lower than Ta, as indicated by the dashed line,
As rapid heating mode M _1, as well as higher than the case of PID control the supply voltage and so as not to change its voltage can be heated at a very early time ta than the time tb until the steady state temperature Ta . When it exceeds this steady state temperature Ta, is set PID control mode M ₂ by a signal from the operation status determination section 36, food will be temperature controlled as shown by the solid line M ₂ in FIG.

As described above, the rapid heating mode M ₁ and the PID
By combining the control mode M _2, the launch and during re-startup of the heating operation, a short time it is possible to set the steady state, the after a steady state maintaining the set temperature Tb with high precision Food and drink can be heated.

The heated food and drink is injected from the storage tank 16 into the container 21. If the operation of injecting the food into the container 21 is performed smoothly, the level of the food and drink in the storage tank 16 becomes higher. Although the level is maintained substantially constant, the level in the storage tank 16 fluctuates when processing is not smoothly performed in the transport device 22 or a process downstream thereof, or when a trouble or failure occurs. Will be.

Therefore, the amount of food and drink in the storage tank 16 is detected by the level sensor 34, and the discharge amount of the pump 14 is controlled based on the detection result so that the level in the storage tank 16 becomes the reference level. I do. When the discharge amount of the pump 14 is changed, when food or drink is to be heated, it is necessary to change a control pattern such as a voltage applied to the electrode 26 and a proportional gain K for PID control.

Therefore, the storage means provided in the control unit 31, that is, a memory 37 such as a ROM, stores an arithmetic expression relating to the correspondence between the discharge amount of the pump 14, that is, the flow rate of food and drink in the heating unit 12, and the energizing condition to the electrodes. Alternatively, map data is stored. Thereby, based on the detection signal from the level sensor 34,
The discharge amount of the pump 14 and energization conditions for the electrode 26 are set.

The discharge amount and the energizing condition may be set in a plurality of steps according to the level, or may be changed steplessly, that is, continuously.

When the food or drink to be heated is, for example, fruit juice, the set temperature Ta is about 40 ° C.
, And the steady temperature Tb is set to about 50 ° C.

FIG. 6 is a flowchart showing a control procedure of the heating device. In step S1, a detection signal from the temperature sensor 33 is read to determine whether or not the heating device is in a steady state. That is, it is determined whether the temperature of the food and drink discharged from the heating unit 12 is equal to or lower than the steady state temperature Ta.

When it is determined that the vehicle is not in the steady state, the rapid heating mode is executed in step S2,
When the food and drink are heated as shown by the dashed-dotted line M ₁ and it is determined that
Control mode is executed, is heated as shown by the solid line M ₂ in FIG.

In step S4, it is determined whether or not the food discharged from the heating unit 12 has reached the set temperature Tb. When the temperature has not reached the set temperature Tb, step S5 is executed. Is executed. In step S5, the control unit 3
From 1, a control signal is sent to the flow path switching valve 18 so that the flow path switching valve 18 is at the disposal position for opening the waste port 19, and in step S 6, a control signal is sent so that the flow path switching valve 18 is at the supply position. Sent. Therefore, if the food or beverage that has flowed out of the heating unit 12 does not reach the predetermined temperature, the food or beverage will be discarded. However, since the food has the rapid heating mode, the amount to be discarded is small. Thus, the yield of the heated product can be improved.

In step S7, the signal from the level sensor 34 is fetched and the amount of food and drink stored in the storage tank 16 is detected to determine whether the storage tank 16 is full, that is, whether or not the storage tank 16 has exceeded a predetermined level. The operation of the heating device is stopped in step S8 when the predetermined level is exceeded.

On the other hand, if it is determined that the level is within the adjustment range, step S9 is executed, and the energization condition is adjusted according to the flow rate of food and drink from the pump 14. As a result, even when the filling operation into the container 21 or the transporting operation after the filling operation is not performed at a constant speed and the discharge amount from the storage tank 16 fluctuates, the heating operation is performed by the heating unit 12. The food and beverage conveyed later into the storage tank 16 can always be discharged after staying in the storage tank 16 for a substantially constant time, and the heating quality of the food and beverage can be improved.

Further, if food or drink stays in the storage tank 16 for a predetermined time or more after heating, it is necessary to discard the food or drink. However, since the amount of such disposal can be reduced, It is possible to improve the product yield.

The present invention is not limited to the above-described embodiment, and it goes without saying that various changes can be made without departing from the scope of the present invention.

For example, although a plurality of pairs of electrodes 26 are provided in the pipe 24 shown in the figure, a heating unit may be formed by connecting pipes provided with a pair of electrodes.

[0046]

According to the present invention, the food or beverage after the heating process can be reliably heated to a predetermined temperature when the heating device is started up or restarted. Product yield can be improved.

Since the flow rate by the pump and the energizing conditions are changed according to the amount of food and drink in the storage tank,
Even if the food and drink are not discharged from the storage tank at a predetermined timing, the food and drink in the storage tank can be discharged within a predetermined time, and the product yield can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a heating device according to an embodiment of the present invention.

2A is a partially cutaway perspective view showing a part of the heating unit shown in FIG. 1 in an enlarged manner, and FIG. 2B is a partially cutaway perspective view showing a modification of the heating unit. It is.

FIG. 3 is a cross-sectional view showing a pipeline incorporated in the heating unit.

FIG. 4 is a block diagram showing a control circuit for controlling the operation of the heating device shown in FIG.

FIG. 5 is a characteristic diagram showing control conditions in a rapid heating mode and a PID control mode.

FIG. 6 is a flowchart showing a control procedure of the heating device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Hopper 12 Heating unit 14 Pump 16 Storage tank 17 Discharge nozzle 18 Flow path switching valve 19 Waste port 21 Container 22 Conveyor 24 Pipe line 26 Electrode 31 Control unit 32 Power supply part 33 Temperature sensor 34 Level sensor 35 Flow rate sensor 36 Operation situation Discriminator 37 Memory Ta Steady state temperature Tb Set temperature

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K058 AA41 AA87 AA88 BA11 CA12 CA23 CA45 CA46 CA58 CB12 CB22 CB26 CE02 CE13 CE17 CE29 FA02 FA05 FA08 FA13 GA06 4B054 AA05 AB11 AC20 BA10 BA18 BB12 BC06 CB04 CH04 CH02 CH05 CH02 CH16

Claims (3)

[Claims] 1. A heating device for heating a food or drink having fluidity as an object to be heated by Joule heat, comprising a pipe provided with electrodes and guiding the object to be heated, and a temperature of the object to be heated. A temperature sensor to be detected; a power supply unit for supplying power to the electrode; and determining whether the heating operation is in a start-up state, a restart state, or a steady state based on a signal from the temperature sensor. An operation status determination unit, when the operation status determination unit determines that the power supply unit is in the start-up state or the restart state, the power supply unit is controlled in the rapid heating mode; And control means for controlling the PID in a PID control mode. 2. A heating apparatus for heating a food or drink having fluidity as an object to be heated by Joule heat, comprising a pipe provided with an electrode and guiding the object to be heated, and after completion of heating by the pipe. A storage tank that stores a predetermined amount of the object to be heated, a level sensor that detects an amount of the object to be heated in the storage tank, a power supply unit that supplies power to the electrode, and a heated object that flows through the pipe. A storage unit for storing a relationship between a flow rate of an object and an energizing condition to be supplied to the electrode; and an energizing condition read from the storage unit based on a signal from the level sensor, and power is supplied to the electrode based on the read energizing condition. A control unit for sending a control signal to the power supply unit to supply the power. 3. The heating apparatus according to claim 2, wherein said energization condition is set in a plurality of steps or in a stepless manner in accordance with a signal from said level sensor.