WO2002071808A1

WO2002071808A1 - Heating and melting device for packaged solid lubricant and control method for the device

Info

Publication number: WO2002071808A1
Application number: PCT/JP2002/001954
Authority: WO
Inventors: Toyoji Ikeda; Eiichi Yoshida; Seiichi Sagara; Yoshihiro Shoji
Original assignee: Fuji Electric Co.,Ltd.; Fuji Oil Co.,Ltd.
Priority date: 2001-03-05
Filing date: 2002-03-04
Publication date: 2002-09-12
Also published as: JPWO2002071808A1; JP3797667B2

Abstract

A heating and melting device for packaged solid lubricant, comprising a side surface heating means for heating at least a part of the side surface of a metal container and a bottom surface heating means for heating the bottom surface thereof, wherein the bottom surface heating means is of the IH (Electromagnetic Inductance Heating) type; a method of controlling the temperature of a heating and melting device for packaged solid lubricant, comprising the step of substantially stopping a heating output after the solid lubricant coming into contact with the inner surface of the metal container heated by the heating means is melted to such a degree, by a heating from the side surface heating means, that a continuous molten phase is formed in an area ranging from the side surface bottom part to the side surface upper part of the metal container; whereby, by utilizing the features of IH, the entire portion of the packaged solid lubricant can be molten safely, cleanly, and very rapidly (approx. 20 minutes depending on the type of solid lubricant) with a simple operation and, since the overheating of the molten lubricant can be suppressed, the quality and taste of the lubricant are not impaired.

Description

Technical Field Apparatus for heating and melting solid oils and fats in cans and control method thereof

The present invention relates to an apparatus for heating and melting solid oils and fats in cans and a method for controlling the temperature thereof. Background art

Conventionally, animal and vegetable oils such as coconut oil, palm oil, and lard, and their hardened oils, extremely hardened oils, and oils and fats that are mainly solid at room temperature, such as margarine, shortening, and chocolate, are stored in metal cans such as cans. It is widely stored, transported, and distributed in containers, but in many cases, its use requires melting by heating and melting to make it easy to handle. As the heating and melting method, there is a merit that there is no problem of overheating deterioration of oils and fats because the heating temperature does not exceed 10 o ° c in the case of the force S, which is a method using a water bath, etc. However, a direct fire such as a gas stove is usually used as a heat source for hot water so there is a danger of fire, and there is also a risk that water from the hot water may enter the oils and fats during handling. In addition, there is a method using a steam room, but in that case, the equipment becomes large-scale. In some cases, a hot air chamber is used, but there is a problem in that power costs increase.

Furthermore, these conventional heating and melting methods usually require about 3 to 4 hours to completely melt the contents, which is not only inconvenient in terms of workability, but also except in the case of a hot air chamber. Because the temperature control is so rough, the actual situation is that after melting, heating is continued more than necessary and wasteful energy is consumed. This is especially true for small or one dozen cans. The problem was with users who used the quantity, such as restaurants, fast food stores, fried food stores, and the like.

On the other hand, as a means for heating an iron-based container, high frequency current is applied to a heating coil placed close to the container to induce eddy currents in the container, and the container is heated by Joule heat. ) It has been known. This electromagnetic induction heating heats the container itself, so it can be heated at a high speed, shortening the work time, and has high thermal efficiency, high safety and cleanliness, easy control and easy operation, etc. It has the advantages of:

The heating coil for electromagnetic induction heating includes a cylindrical coil having a spirally wound winding and a spiral coil having a disk wound. Cylindrical coils are used, for example, for heating coffee cans in canned beverage vending machines. However, this cylindrical coil requires the container to be heated in and out in the axial direction of the heating coil. There is a problem that loading and unloading the container is burdensome. By the way, the weight of a dough can with food is close to 2 O kg. In addition, it is difficult for cans with a rectangular cross section to even out heat generated by the conductive current, especially at the corners of the can.

On the other hand, spiral coils are disc-shaped and open on the sides, so they do not hinder the loading and unloading of containers, and are used in electromagnetic cookers that cook food by heating the pan bottom. . This spiral coil is also suitable for heating a can. As in an electromagnetic cooker, the can can be easily heated by placing the can above a horizontally installed heating coil.

However, when a method of inductively heating the bottom of the can using a spiral coil was actually tried, it was found that the can expands as the heating progresses and bursts when heating is continued. found.

The present invention provides a rapid and efficient heating and melting method without deterioration of the contents. It is an object of the present invention to obtain a heating and melting apparatus for solid oils and fats in cans, which is capable of: Disclosure of the invention

The inventors repeated heating experiments and worked to determine the cause of the above-mentioned expansion of the can. As a result, the following phenomena were found. Honkiaki is based on that knowledge.

In other words, when the bottom of a can filled with solid fats and oils is heated, the solidified material starts to melt from the bottom due to heat transfer from this bottom, but the volume of the molten layer at the bottom increases due to body expansion of the fats and oils at that time. . In addition, among the components of air and solids contained as air bubbles in solid fats and oils, components having relatively low boiling points expand as gas and expand further. However, the upper part of the solid fat is still solidified, and the upper part of the molten layer is sealed with a so-called plug. As a result, the expanded fats and oils have nowhere to go and cause the can to expand and eventually burst. Therefore, the inventors thought that the fats and oils and gases expanded during the melting process were allowed to escape upward, and by taking the following measures, the cans could be prevented from expanding.

That is, as a result of intensive studies in view of the above problems, the present inventors have started the development of a compact heating and melting apparatus for one dough can that employs electric heating means, It has been found that by properly controlling the installation position and the heating means, the solid fats and oils in the can can be efficiently heated and melted, and the present invention has been completed. That is, the present invention has a side surface heating means for heating at least a part of the side surface of the metal can and a bottom surface heating means for heating the bottom surface, and the bottom surface heating means is IH. The solid fats and oils in a can that is heated and melted by the cans and the solid fats and oils in contact with the inner surface of the metal can heated by the heating means. The main point of the method is to control the temperature of the heating and melting device for solid fats and oils in cans that stops the heating output after the products have melted to the extent that they form a continuous molten phase from the bottom to the top of the side.

As the heating means, an electric heater, IH, etc. can be adopted.However, in the case of using IH, due to the heating efficiency of IH, the metal can is made of a magnetic plate such as a tin can as represented by a can. Are preferred. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a longitudinal sectional view of a solidified substance melting device in a can showing a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a canned solidified material melting apparatus according to a second embodiment of the present invention.

FIG. 3 is a plan view of FIG.

FIG. 4 is a left front view of FIG.

FIG. 5 is a control block diagram of the device of FIG.

FIG. 6 is a perspective view of a canned solidified material melting apparatus according to a third embodiment of the present invention.

FIG. 7 is a vertical sectional view of a tester used for determining a preset value in the present invention.

FIG. 8 is a top view showing the position of the resistance temperature detector in FIG.

FIG. 9 is a graph showing the results measured by the tester of FIG. FIG. 10 is a longitudinal sectional view schematically showing a state of melting of a material to be melted when the apparatus of the present invention is used. BEST MODE FOR CARRYING OUT THE INVENTION

The following is an example of melting solid fats and oils contained in a can using the apparatus of the present invention. The present invention will be described as follows. FIG. 1 shows a first embodiment of the present invention. 6 is a spiral-shaped induction heating coil for a bottom surface as a means for heating the bottom surface, 5 is a spiral-shaped induction heating coil for a side surface as a heating means for the side surface, 4 is a magnetically transparent dough can mounting plate (bottom plate), 3 Is a plate (side plate) made of a magnetically permeable material. A small vertical hole is provided near the center of 4 and a sensor for detecting the surface temperature of the can (bottom temperature sensor) is insulated from the plate. 8) has been fixed. Similarly, a sensor (surface temperature sensor) 7 for detecting the surface temperature of the side surface of the can is fixed to the side plate 3. The bottom and side heating means 5 and 6 are connected to a high frequency generator 9 of 20 to 25 kHz so that high frequency energy generated by the high frequency generator 9 can be supplied. Reference numeral 10 denotes an energization control unit for separately controlling electric conduction to the side-surface induction heating coil 5 and the bottom-surface induction heating coil 6, and an operation panel (not shown) is provided at an upper part of the housing 11. .

The operation panel has operation buttons for presetting heating temperature, heating time, heating temperature by side heating means, heating time, and heat retention temperature and heat retention time according to the type of fat and oil. In addition to the display means, means for instructing the start of heating is provided. The preset data can be stored in a semiconductor nonvolatile memory installed in the device.

Open the dough can 1 containing about 18 L of extremely hardened rapeseed oil as the solid fat 2 on the dough can mounting plate (bottom plate) and place it. Then call the preset data for extremely hardened rapeseed oil from the operation panel. After presetting and instructing to start heating, first, 5 KW of electric power (high frequency) is supplied to the side surface heating means 5. The electric power supplied to the side heating means 5 is PID controlled in accordance with the surface temperature of the side canister detected by the temperature sensor 8 for the side surface. After reaching the preset temperature) After the solid oils and fats in contact with the inner surface of the dough heated by the heating means 5 are melted to such an extent that a continuous molten phase is formed from the bottom to the top of the side, the side heating means 5 Stop supplying power to the power supply and switch to supplying power to bottom surface heating means 6. The stop timing is determined by the preset value, and the value can be as short as about 1 minute. In addition, it is possible to supply power to both heating means 5 and 6 at the same time, or to continue supplying weak power without stopping the power supply to the side heating means 5, but as described above, due to the circuit design, It is convenient to switch the electric power from the side heating means 5 to the bottom heating means 6. When the continuous molten phase is formed, the heated and melted bottom of the bottom surface flows to the upper part along the side of the continuous molten phase, so that even if the heating of the side surface is stopped, the continuous molten phase remains in the molten state. Will be maintained.

The power supplied to the bottom surface heating means 6 is PID controlled by the detection value of the bottom surface temperature sensor 8, and the surface temperature of the bottom surface of the can is maintained at a preset value.

After the heated and melted fat on the bottom surface flows to the upper part, the unheated solid fat is near its heated surface on its bottom surface due to its own weight. (A difference in specific gravity occurs), so that efficient heating can be performed. That is, since the unheated solid oil is always present near the heating surface, the thermal energy supplied to the bottom of the dough can be efficiently conducted to the object to be heated, and the energy loss due to unnecessary radiant heat is suppressed. Good thermal efficiency.

If the heating by the side heating means 5 is not performed at all, or if a continuous molten phase is not formed even after the heating, the fats and oils near the bottom surface are overheated, and the quality of the fats and oils (including the deterioration of flavor) is brought about. In severe cases, there is no place for the expanded fats and oils to go out and the dough can rupture (joint breaks). There is also. On the other hand, if the heating is continued by the side surface heating means 5 even after the continuous molten phase is formed, the temperature of the oil or fat in excess of the oil or fat in contact with the side surface of the dough can, which is a heating element, has already been melted. The rise causes a decrease in thermal efficiency and deterioration of oil and fat quality. If heating by the side heating means 5 is to be continued, it should be minimized.

Surprisingly, the side heating means 5 does not need to be installed so as to heat the entire periphery of the side surface of the metal can, and the object can be achieved by providing at least one part as described above. . In the case of a can with a rectangular cross section, such as a can, it is sufficient to heat one side for a short time, which reduces the number of heating coils and the capacity of the high-frequency power supply. Also, if the heating coil on the side is small, it will not be necessary to put the can in and out. Shortly after the formation of the continuous molten phase on the side surface, the convection of the molten phase inside the can becomes active, and the solid phase melts while being in a thermal steady state between the solid phase and the molten phase. In order to maintain such a steady state, it is important to set the amount of electric power to be supplied to the bottom surface heating means, which will be described later.

After the whole is melted, the electric power supplied to the bottom surface heating means 6 is reduced, and the state is shifted to a warm state. However, if the melting does not need to be done so quickly, it is possible to make a transition to a warm state without waiting for the whole to completely melt, and to completely dissolve. The heat retention temperature and the heat retention time are determined according to the preset values as described above. The preset value (temperature) is set to a temperature that is higher than the melting point of the material to be melted, does not impair workability, and does not deteriorate quality.

In addition, in order to prevent empty cooking, there is a circuit that cuts off the power supply to the heating means 5 and 6 when the temperature exceeds the heating upper limit (180 ° C) based on the detection values of the temperature sensors 7 and 8. . Next, a second embodiment of the present invention will be described with reference to FIGS. Note that, in FIG. 1 and each figure, components denoted by the same reference numerals have approximately the same functions, and redundant description may be omitted.

2 is a longitudinal sectional view of the melting apparatus, FIG. 3 is a plan view of FIG. 2, and FIG. 4 is a left front view of FIG. 2 to 4, the main body 11 is made of a stainless steel plate, and is formed in an L-shaped box shape including a horizontal portion 11a and a vertical portion 11b. The horizontal portion 11a serves as a platform for the can 1, and the can 1 is supported as shown so that the side surface of the can 1 contacts the vertical portion 11b. Horizontal part 1 The part on which the 1a dough can 1 is placed is formed of a ceramic plate (bottom plate) 4 with a thickness of several mm, and is a spiral-shaped bottom guide with a diameter of about 300 mm close to the back surface. A heating coil 6 is arranged. The portion of the vertical portion 11b that contacts the can 1 is also formed of a similar ceramic plate (side plate) 3, and a similar side-surface induction heating coil 5 is arranged near the back surface thereof. The level of the main body 11 is adjusted by a jack 11c.

A pair of left and right guide members 21 for guiding the can 1 to the illustrated position is provided on the upper surface of the horizontal portion 11a. The guide member 21 is also made of a stainless steel plate, and the space at the inlet side (left side in FIG. 3) is widened so as to avoid the influence of the induction heating coil 6 for the bottom surface, and the end at the back side (right side in FIG. 3). The distance between them is determined by the width of the can 1 and this end is abutted on a vertical ceramic plate 3. With the guide member 21, the can 1 is placed on the end of the placing stand 11 a as shown by a chain line in FIGS. 2 and 3, and is slid and pushed in until it hits the vertical part 11. Thus, the left and right positions of the can 1 are shifted by the guide member 21 and positioned.

Here, the horizontal part 11a of the main body is divided into two parts so that it can be separated vertically, and an induction heating inverter (IH impeller) that supplies a high-frequency current of 20 to 25kHz to the heating coils 5 and 6 in the lower box body High frequency generator 9 such as It is included with the energization control unit 10 (see Fig. 5). In the drawing, the horizontal portion 11a has the upper and lower portions integrally stacked, but the lower portion can be separated and placed separately. On the other hand, the upper surface of the main body vertical portion 11b is formed obliquely, and an operation panel 12 composed of a touch key is disposed in this portion.

FIG. 5 shows a control block diagram of the above device. As shown in FIG. 5, at the center of the ceramic plates 3 and 4, temperature sensors 7 and 8 each consisting of a thermistor for detecting the temperature of the side surface and the bottom surface of the can 1 are mounted by embedding, and the detection signals are provided. It is input to the power supply control unit 10 composed of CPU. From the operation panel 12, control data according to the type of the contents of the can 1 is set and input to the energization control unit 10, and the energization control unit 10 heats according to a predetermined program based on the control data. Control the energization of coils 5 and 6 separately. Reference numeral 13 denotes a contactor for switching the energization between the side-surface induction heating coil 5 and the bottom surface induction heating coil 6. The operation method in the second embodiment shown in FIGS. 2 to 5 is the same as that in the first embodiment shown in FIG. 1, and thus detailed description is omitted, but also in the second embodiment. First, electric power is supplied to the induction heating coil 5 for the side surface, and the dough 1 heated by the induction heating coil 5 for the side surface solid oils and fats in contact with the inner surface form a continuous molten phase from the bottom to the upper side. After melting to the extent, the power supplied to the side induction heating coil 5 is stopped and switched to the power supply to the bottom induction heating coil 6 to dissolve the solid fats and oils. Although the apparatus shown in FIGS. 2 to 5 is of a single-unit type, as shown in FIG. 6, it is also possible to adopt a configuration in which a plurality of units are arranged side by side in a row. Also, the above-described energization control based on the control block diagram shown in FIG. 5 is, of course, an example, and it is possible to perform more complicated automated control, particularly for the twin machine shown in FIG. Or manually switch between induction heating coil 5 for the side and induction heating coil 6 for the bottom for small-scale users Such a simple specification can also be configured.

Finally, the temperature control and preset values of the present invention and the manner of melting of the material to be melted when the apparatus of the present invention is used will be described in detail using a test machine.

Figures 7 and 8 show the test machine. 3 1 to 3 5 are thermometers (resistance temperature detectors). As shown in the figure, 3 1 is the upper part of the center of the can, 3 2 is the center of the can, 3 3 is the bottom of the center of the can, and 3 4 is the can of the can. The middle corner (non-heated side), 35 can measure the temperature of the grease in the middle of the heated side. Reference numeral 36 denotes a temperature converter for converting the resistance values of the thermometers 31 to 35 into temperature, and the measured temperature is output from the printer 38 via the CPU 37. Figure 9 (graph) shows the results of using this tester to determine the steady state by varying the amount of power and time applied to the bottom and side heating means. FIG. 10 schematically shows the state of melting of the material to be melted at that time. FIG. 9 is a graph when extremely hardened oil is used as the material to be melted.

First, when power is supplied to the induction heating coil 5 for the side (this time is the starting point of the graph: 0 0: 0 0), the heating of the side of the canister is started and the vicinity of the side is rapidly (approximately 1 minute). The fat melts above 150 ° C (as indicated by the thermometer 35 in the graph). At this point, the solid fat melts to the extent that a continuous molten phase is formed from the bottom to the top of the side (state 1), and a part of the melt flows to the top of the solid fat by thermal expansion (state 2). .

Therefore, the power supply is stopped, and the power supply is switched to the bottom induction heating coil 6. Since the purpose of side heating is to form the continuous molten phase as quickly as possible, the temperature of the continuous molten phase is usually 150 to Select a preset value for side heating so that the temperature is as high as about 200 and the time is short (about 1 minute).

Once the states 1 and 2 are formed, the melt that has been heated and melted at the bottom The melted material flows upward through the side surface, and after a while, a continuous molten phase is formed on all sides of the can (State 3), and the solid fat sinks down due to its large specific gravity, and is always near the heated surface. The heat energy supplied to the bottom of the can can be efficiently conducted to the object to be heated and consumed as melting energy for melting fats and oils (solid phase). Soon, the convection of the molten phase inside the can becomes active (state 4), and the solid phase and the molten phase become in a thermal steady state (in the graph, there is a flat portion near 100 ° C). It can be understood from its appearance).

However, the steady state depends on the amount of energy input and the melting rate of the solid phase, and the melting rate (surface area of the remaining solid phase, thermal conductivity, viscosity of the liquid phase, temperature difference from the melting phase, etc.). If more than the specified amount of melting per unit time is applied, the steady state is liable to collapse, and only the melting phase temperature rises rapidly, causing quality deterioration. The steady-state temperature is set at a temperature close to the upper limit where the steady-state is maintained and the quality (including flavor) does not cause any deterioration according to the type of fat.

In this experiment, in the case of extremely hardened rapeseed oil (melting point 61.5 ° C), the temperature in the steady state was set at 100 ° C. In this way, the preset value (temperature) of the bottom surface heating means is set so that the inside of the can becomes a steady state temperature. The preset value (time) should be set by correcting the outside temperature based on the time required for the entire amount of the material to be melted. If rapid thawing is not required, the transition to the warm state can be made earlier. Industrial applicability

As described above, according to the apparatus and the melting method of the present invention, taking advantage of the features of IH, it is extremely quick (with about 20 minutes depending on the type of solid fats and oils) by safe, clean and simple operation. Melting the entire solid fats and oils in cans In addition, since overheating of the molten fat is suppressed, the quality and flavor of the fat and oil are not impaired.

Claims

The scope of the claims

1. It has side heating means for heating at least a part of the side surface of the metal can and bottom heating means for heating the bottom, and the bottom heating means is IH (electromagnetic induction heating). A heating and melting device for solid fats and oils in cans.

2. The apparatus for heating and melting solid fats and oils contained in a can according to claim 1, wherein the metal can is a single can.

3. The heating power is substantially reduced after the heating by the side heating means is completed until the solid fats and oils in contact with the inner surface of the metal can heated by the heating means are melted to the extent that a continuous molten phase is formed from the bottom to the top of the side. 2. The method for controlling the temperature of a heating and melting apparatus for solid oils and fats in cans according to claim 1, wherein the temperature is stopped.

4. The apparatus for heating and melting solid fats and oils in cans according to claim 1, wherein the side heating means is IH.

5. In a melting device for solid fats and oils in a can which heats and melts solid fats and oils filled in a rectangular cross-section can made of a magnetic plate, a table for supporting the cans and a table for supporting the cans A spiral bottom heating coil disposed so as to face the bottom surface of the can, and a spiral side heating coil also disposed so as to face the side surface of the can. An apparatus for heating and melting solid oils in cans, comprising: a high-frequency power supply for energizing the coil; and energization control means for separately controlling energization of the bottom surface heating coil and the side surface heating coil.