JP7158664B2 - Safety value calculator for heating units - Google Patents

Description

The present invention provides a joule heating unit having a heating tube consisting of an annular electrode and a cylindrical member to obtain a safe value as an indicator of whether or not an object to be heated can be heated without causing defective heating. It relates to a unit safety value calculator.

As a heating device, that is, a Joule heating unit, which electrically heats fluid food and drink by Joule heat as an object to be heated, as described in Patent Document 1, a plurality of annular electrodes are arranged between the electrodes. Some have a heater or heating tube consisting of a plurality of cylindrical members of insulative material coated with a heat-resistant material. This joule heating unit is formed, for example, by connecting four heating tubes, and electric power is supplied to the electrodes of the respective heating tubes from the power supply unit. As a joule heating unit, there is a type in which a stirring shaft having a stirring member is incorporated in a heating tube, as described in Patent Document 2.

The heating tube has predetermined system components such as inner diameter and inter-electrode length. adjusted.

Japanese Patent No. 5438709 Japanese Patent No. 2821087

A single Joule heating unit can heat a plurality of types of objects to be heated having different physical properties. When heating a certain type of heated object and then heating another type of heated object, the physical properties of the heated object are different and the processing conditions are also different. Processing conditions for the heated object are set. The object to be heated is processed under processing conditions based on empirical rules, and it is determined whether or not the heat processing has been properly performed. If the heat treatment is not performed properly due to scale or scorching on the inner wall of the heating tube or sparks on the object to be heated, change the treatment conditions to ensure proper electric heating. The heat treatment of the object to be heated is repeated until the heat treatment is performed. Depending on the type of object to be heated, not only the processing conditions are changed, but also the system elements such as the number of heating tubes constituting the joule heating unit are changed.

On the other hand, when designing and manufacturing a heating unit consisting of a plurality of heating tubes and a power supply unit, system elements are designed according to the type of object to be heated and processing conditions. A joule heating unit equipped with designed system elements is manufactured and used to heat an object to be heated, and it is confirmed whether or not a heating failure occurs.

However, actually heat-treating an object to be heated and determining processing conditions and system elements not only takes time, but also produces a large amount of food and drink that must be discarded. Therefore, if a safe value can be calculated as a guideline for determining the system elements of the Joule heating unit and the processing conditions of the object to be heated according to the physical properties of the object to be heated, the system elements and the processing conditions can be easily determined.

SUMMARY OF THE INVENTION An object of the present invention is to enable calculation of an index as a safe value indicating whether or not an object to be heated can be heat-treated without causing defective heating by a joule heating unit.

The safety value calculation device for a heating unit according to the present invention is a heating tube having a cylindrical member made of an insulating material and a plurality of annular electrodes provided on the cylindrical member, while conveying food as an object to be heated. A safety value calculation device for a heating unit that calculates a safety value when a joule heating unit is operated, comprising: a system element input unit for inputting system elements of the joule heating unit; A physical property input unit, a processing condition input unit for inputting processing conditions for an object to be heated by the Joule heating unit, and an index of whether or not heating failure will occur based on the system elements, the physical properties, and the processing conditions. It has a safe value calculator that calculates a certain safe value, and a display that displays the safe value calculated by the safe value calculator.

The safety value calculation device for a heating unit according to the present invention is a heating tube having a cylindrical member made of an insulating material and a plurality of annular electrodes provided on the cylindrical member, while conveying food as an object to be heated. A safety value calculation device for a heating unit that calculates a safety value when a joule heating unit is operated, comprising: a system element input unit for inputting system elements of the joule heating unit; A physical property input unit, a processing condition input unit for inputting processing conditions for an object to be heated by the Joule heating unit, and an index of whether or not heating failure will occur based on the system elements, the physical properties, and the processing conditions. a safe value calculator that calculates a certain safe value; and a display that displays the safe value calculated by the safe value calculator . including later temperature and flow rate.

Fig. 2 is a schematic diagram showing a joule heating unit; 2 is an enlarged cross-sectional view of the heating tube shown in FIG. 1; FIG. It is a partially-omission sectional view which shows the modification of a heating pipe. FIG. 2 is a block diagram showing a controller of the Joule heating unit 10 shown in FIG. 1; FIG. FIG. 3 is a block diagram showing a safety value calculator for a heating unit; 4 is an initial correction value table showing initial correction values obtained from the Reynolds number and the properties of the object to be heated; 5 is a final correction value table showing final correction values based on the inner diameter of the heating tube; It is a table|surface which shows an example of the safe value calculation result based on an input condition. FIG. 11 is a table showing another example of safety value calculation results based on input conditions; FIG. (A) to (D) are block diagrams showing changes in safety values and heating conditions.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. A Joule heating unit 10 shown in FIG. Into the hopper 13, liquid food such as juice, soup, jam, miso, etc. is put as the object W to be heated. The charged object W to be heated is supplied to the Joule heating unit 10 through the supply pipe 14 . The object to be heated W in the hopper 13 is supplied to the first-stage heating pipe 11 through the preheating section 16 by the pump 15 provided in the supply pipe 14 . The object W to be heated is supplied from the flow path of the heating tube 11 in the first stage to the flow path of the heating tube 11 in the fourth stage via the connecting tube 12 and is electrically heated to a predetermined temperature. The heated object W to be heated is transported to a post-process through the discharge pipe 17 . The post-process includes, for example, a holding process of holding the object W to be heated for a certain period of time, a cooling process of cooling the object W after passing through the holding process, and a filling process of filling the object W to be heated into a packaging container or the like. There is

Incidentally, as the preheating section 16, a Joule heating type tube may be used like the heating tube 11, and the object W to be heated may be preheated by a heat medium. Moreover, when the preheating unit 16 is not used, the object to be heated W in the hopper 13 is directly supplied to the heating pipe 11 in the first stage.

Each heating tube 11 consists of seven annular electrodes 21 and a cylindrical member 22 arranged between two adjacent electrodes 21, as shown in FIG. The electrode 21 is made of a conductive material such as titanium, and the cylindrical member 22 is made of an insulating material such as resin. Joints 23 and 24 are provided at both ends of the heating tube 11, respectively. A connection pipe 12 connects between the two heating pipes 11, a supply pipe 14 is connected to the joint 23 of the heating pipe 11 in the first stage, and a discharge pipe 17 is connected to the joint 24 of the heating pipe 11 in the fourth stage. Connected.

Two electrodes 21 arranged at both ends of each cylindrical member 22 form a pair, and high-frequency current is supplied from a power supply unit 25 so that the two electrodes 21 forming a pair have mutually opposite polarities. . When an electric current flows between the pair of two electrodes 21 via the object W to be heated, Joule heat is generated in the object W to be heated, and the object W is electrically heated by the Joule heat. The number of electrodes 21 constituting one heating tube 11 is not limited to seven as long as it is plural, and can be arbitrarily set according to the physical properties of the object W to be heated and the processing conditions such as the heating temperature. Similarly, the number of heating tubes 11 constituting one Joule heating unit 10 is not limited to four, and may be set to any number according to the flow rate of the material to be heated.

FIG. 3 shows a modification of the heating tube 11. As shown in FIG. This heating tube 11 has a stirring shaft 27 provided with a stirring member 26 . An electric motor 28 is attached to one joint 24 , one end of a stirring shaft 27 is connected to a main shaft (not shown) of the electric motor 28 , and the other end of the stirring shaft 27 is rotatably supported by the other joint 23 . It is Each stirring member 26 is arranged radially inside the electrode 21 . Each electrode 21 is connected to a power supply unit 25 similar to that shown in FIG. 2, but the power supply unit 25 is omitted in FIG. As described above, the heating tube 11 includes a type in which the stirring shaft 27 is incorporated as shown in FIG. 3 and a type in which the stirring shaft 27 is not provided as shown in FIG.

FIG. 4 is a block diagram showing the controller 30 of the joule heating unit 10 shown in FIG. The control device 30 has four power supply units 25 that supply power to the four heating tubes 11 and a control section 31 for controlling the pump 15 . Driving conditions for the power supply unit 25 and the pump 15 are input by an operator operating an input section provided on the operation panel 32 . The input value is lit up on the display section of the operation panel 32 . As shown in FIG. 1 , when the preheating section 16 is provided, the preheating section 16 is also controlled by the control section 31 . The control unit 31 has a microprocessor that calculates control signals, and a memory that stores control programs, map data, and the like.

The Joule heating unit 10 shown in FIG. 1 has four heating tubes 11, and the number N of the heating tubes 11 as system elements is four. As shown in FIG. 2, each heating tube 11 has an inner diameter D and a distance L between two paired electrodes 21, that is, an inter-electrode distance. Assuming that one section number P is formed from one cylindrical member 22 and one electrode 21 combined with one end face thereof, the heating tube 11 has six section numbers P. As shown in FIG.

The number N, the inner diameter D, the inter-electrode distance L, and the number of sections P described above are system components of the Joule heating unit 10, that is, system elements. As shown in FIG. 3, in the heating tube 11 provided with the stirring shaft 27, the diameter of the stirring shaft 27 is also one of the system elements. In order to appropriately heat the object W to be heated by the Joule heating unit 10 having such system elements, the characteristics, that is, the physical properties of the object W to be heated and the processing conditions of the object to be heated by the Joule heating unit 10 must be met. considered to be an important factor.

Food and drink as the object to be heated W includes food and drink that contain starch and gelatinize when heated, and food and drink that contain little or no starch and do not gelatinize when heated. Whether or not to gelatinize is an important factor as a physical property of the object W to be heated, that is, a physical property value. Furthermore, the viscosity μ (mPa·s) and the specific gravity M are also factors that indicate the physical properties of the object W to be heated.

On the other hand, the processing conditions for the object to be heated include the temperature T1 (° C.) of the object to be heated before heating, the temperature T2 (° C.) of the object to be heated after heating, and the flow rate Q (L/h). The temperature T1 before heating is the temperature of the object W to be heated at the inlet of the heating tube 11 in the first stage, and the temperature T2 after heating is the temperature of the object W to be heated flowing out of the heating tube 11 in the fourth stage, that is, the final stage. temperature. The flow rate Q (L/h) is set by the rotational speed of the pump 15 . A temperature difference .DELTA.T (.degree. C.) between the temperature T2 after heating and the temperature T1 before heating indicates the temperature raised by heating the object to be heated W by the four heating pipes 11, that is, the heating temperature.

When the object W to be heated is Joule-heated by the Joule heating unit 10, boiling or scale formation on the inner wall surface of the heating tube 11 may lead to scorching or sparking. If such a phenomenon occurs, it becomes a heating failure. An object to be heated that has been poorly heated, that is, food and drink cannot be commercialized. Furthermore, if the heating failure increases, the joule heating unit 10 may be damaged. It is considered that the power density Ed (kW/m ³ ) of the power flowing through the object W to be heated greatly affects the conditions for safe and appropriate heat treatment without causing defective heating. The power density Ed (kW/m ³ ) is given by E0 (kW) as the power supplied and S (m ² ) as the cross-sectional area calculated from the inner diameter D (m) of the heating tube 11. is calculated by the following formula [1] based on

Power density Ed=E0/(S×L×P×N) [1]
Further, the Reynolds number Re calculated from the physical property value indicating the physical properties of the object to be heated W and the inner diameter of the heating tube 11 is the flow velocity V of the object to be heated in the heating tube, the inner diameter D, the cross-sectional area S of the heating tube 11, the It is calculated by the following formula [2] from the viscosity μ (mPa·s) and the specific gravity M of the heated object.

Reynolds number Re=V[4·{S/(πD)}·M·1000/(μ/1000)]...[2]
As described above, on the inner wall surface of the heating tube 11, based on the correlation among the system elements constituting the joule heating unit 10, the physical properties of the object to be heated, and the processing conditions of the object W to be heated by the joule heating unit 10, A guideline or a safe value as an index was studied to enable appropriate heat treatment without causing defective heating such as scales or scorching. If such a safe value Sv is obtained, when the type of the object W to be heated by the joule heating unit 10 is changed, by changing the physical property values of the object W to be heated and the processing conditions, a safe value can be obtained. A value Sv is determined. If the obtained safe value Sv is an inappropriate value, proper heat treatment can be performed by changing the processing conditions so that the safe value becomes proper. As a result, a new object to be heated can be rapidly heat-treated without actually using the object to be heated and performing a trial heat treatment. Elimination of the need for the experimental heat treatment can prevent the generation of objects to be heated that are discarded due to poor heating.

On the other hand, when designing the joule heating unit 10, the system elements of the joule heating unit 10 are determined, and the values thereof, the physical property values corresponding to the type of the object to be heated W, and the processing conditions are input and calculated. Thus, it can be determined whether the system components of the Joule heating unit 10 are correct. The Joule heating unit 10 manufactured based on the determined design values can be commercialized only by heat-treating the object W to be heated for confirmation.

As a result of conducting heating tests on various objects to be heated using various joule heating units, an arithmetic expression for calculating a safe value for heat treatment by the joule heating unit 10 was found.

Experiments have shown that the safe value Sv basically depends on the power density Ed (kW/m ³ ) and is correlated with the logarithm of the power density Ed with a base of 1.6. In order to improve the accuracy of the safety value Sv, it is preferable to correct the safety value obtained from the power density using the Reynolds number Re and the initial correction value K1 obtained from the properties of the object W to be heated. Furthermore, in order to improve the accuracy of the safe value Sv, it is preferable to multiply the safe value after the initial correction by the final correction value K2 based on the inner diameter D of the heating tube 11. FIG.

Therefore, the safe value Sv is calculated by the following formula [3].

Safe value Sv = (log _1.6 Ed - K1) x K2 ... [3]
FIG. 5 is a block diagram showing the safety value calculator 40 of the joule heating unit 10. As shown in FIG. The safe value calculator 40 has a safe value calculator 41 that calculates a safe value Sv, and an input unit 42. The input unit 42 constitutes a system element input unit, a physical property input unit, and a processing condition input unit. As system elements, the number N, the inner diameter D, the inter-electrode distance L, and the number of sections P are input to the input unit 42 . As the physical property values, whether or not the object W to be heated is gelatinized, the viscosity μ, and the specific gravity M are input to the input unit 42 . As processing conditions, a flow rate Q (L/h), a temperature T1 (° C.) before heating, and a temperature T2 (° C.) after heating are input to the input unit 42 .

When these values are input, the safety value calculation unit 41 calculates the safety value Sv according to the formula [3], and the calculation result is displayed numerically on the display unit 43 . The formula for calculating the safety value is stored in memory 44 .

FIG. 6 is an initial correction value table showing the initial correction value K1 obtained from the Reynolds number Re and the physical properties of the object to be heated. FIG. 7 is a final correction value table showing the final correction value K2 based on the inner diameter D of the heating tube 11. As shown in FIG. Data corresponding to these correction value _tables are stored in the memory 44 in the form of map data, for example. do. Furthermore, the final safety value Sv is calculated by multiplying the initial corrected safety value by the final correction value K2.

The initial correction value K1 differs depending on whether or not the object W to be heated has the property of gelatinization. divided into two patterns. Pattern [1] is the case of the joule heating unit 10 having a heating tube 11 with a nominal diameter of 2S stirring or 3S stirring for an object to be heated to be gelatinized and a stirring shaft 27 provided. As shown in FIG. 7, the inner diameter of the heating tube 11 for 2S stirring is 0.0320 m, and the inner diameter of the heating tube 11 for 3S stirring is 0.0464 m. As the initial correction value in this case, a constant value of "-1.5" is set.

Patterns [2] to [5] are for Joule heating units 10 having heating tubes 11 other than 2S stirring or 3S stirring. When heating the gelatinized material while flowing it at a flow velocity V of less than 0.1 m/s, the initial correction value K1 is set to a constant value of "-8" regardless of the Reynolds number Re. be done. Furthermore, when the gelatinized material is heated while flowing at a flow rate V of 0.1 or more, the initial correction value K1 is set to a constant value of "-4" regardless of the Reynolds number Re. be.

When heating an object to be heated that does not gelatinize, as shown in patterns [4] and [5], regardless of the heating tube 11 and the flow velocity V, the Reynolds number Re is less than "2" or "2 , the initial correction value K1 is set. When the Reynolds number is less than "2", the initial correction value K1 is calculated by the following linear function [4].

y=a.Re+b...[4]
Constant a is 1/1.95 and constant b is -2.975/1.95.

When the Reynolds number Re is "2" or more, the initial correction value K1 is calculated by log ₁₀ Re.

As shown in FIG. 7, the final correction value K2 is set to "7" when the object to be heated is gelatinized when heated. On the other hand, when the object to be heated does not gelatinize, the final correction value K2 is set according to the inner diameter D of the heating tube 11, respectively. The symbols of the heating tube 11 shown corresponding to the inner diameter D are nominal diameters defined by JIS. As the joule heating unit 10, one having a heating tube 11 having an inner diameter D shown in FIG. 7 is used.

To calculate the safety value Sv described above, first, the value of log _1.6 power density Ed is calculated as shown in equation [3], and the initial correction value K1 is subtracted from this value. Next, the value after subtraction is multiplied by the final correction value K2 to calculate the safe value Sv.

The safety value calculation device 40 shown in FIG. 5 can be configured by a personal computer. Further, the data of the initial correction value K1 shown in FIG. 6 and the data of the final correction value K2 shown in FIG. 7 are stored in the memory of the controller 31 shown in FIG. The safe value Sv may be calculated by the control unit 31 based on (Equation [3]). In that case, the system elements of the Joule heating unit 10 are set in the control unit 31 as shown in FIG. Sv is required. If the obtained safe value Sv is a value that does not cause defective heating, the object W to be heated can be heat-treated based on the data stored in the memory of the control unit 31 .

On the other hand, as shown in FIG. 5, if the safe value Sv calculated by the safe value calculator 40 separated from the controller 30 of the joule heating unit 10 is a value that does not cause defective heating, the controller 30 Contains system element data. When the object W to be heated is heated using the joule heating unit 10, data of physical property values and processing conditions are also stored in the memory.

FIG. 8 is a table showing an example of safety value calculation results based on input conditions, and FIG. 9 is a table showing another example of safety value calculation results based on input conditions.

As shown in FIGS. 8 and 9, numerical values such as the number N of the heating tubes 11 and the inner diameter D of the heating tubes 11 are input as system elements through the system element input unit, and the processing conditions for the object to be heated are the flow rate Q , temperatures T1 and T2 are input by the processing condition input unit. Also, the specific gravity M indicating the physical properties of the object to be heated, whether gelatinization occurs or not, and the viscosity μ are input through the processing condition input unit.

The cross-sectional area S is calculated based on the inner diameter D of the heating tube 11 , and is calculated based on the diameter of the stirring shaft 27 and the inner diameter D in the heating tube 11 provided with the stirring shaft 27 . The flow velocity V is calculated based on the flow rate Q and the cross-sectional area S. The Reynolds number Re is calculated by Equation [2] based on the flow velocity V, the inner diameter D, etc., as described above. The power density Ed is calculated by the formula [1] mentioned above.

Once the power density Ed is found, log _1.6 Ed is calculated to find the base safe value. This value is corrected by the above equation [3] using the initial correction value K1 and the final correction value K2, and the final safe value Sv is calculated.

When the object to be heated shown in FIG. 8 is Joule-heated under the processing conditions shown in FIG. 8 by means of the heating tube 11 of the system elements shown in FIG. 43. When the object to be heated shown in FIG. 9 is Joule-heated under the processing conditions shown in FIG. 9 by means of the heating tube 11 of the system elements shown in FIG. 43.

As a result of experiments, if the safe value Sv obtained by using the formula [3] is less than "110", no scale or scorching occurs on the inner wall surface of the heating tube 11, and sparks do not occur. Proper heat treatment was performed. As shown in FIG. 8, when the object to be heated was treated by the joule heating unit 10 of the system element whose safe value Sv is less than "110", the optimum heat treatment could be performed without causing any heating failure. . On the other hand, when the safe value Sv was "113" or more, scale and scorching occurred, and proper heat treatment could not be performed. If the safe value is in the range of "110" or more and less than "113", scaling or boiling may occur, so it is necessary to carefully observe the heating situation. As shown in FIG. 9, when the object to be heated was treated by the joule heating unit 10 of the system element having a safe value Sv of "110" or more, the object to be heated could be appropriately heat-treated in a steady state. After a long period of continuous operation, the inner wall surface of the heating tube 11 was found to have traces of what seemed to be scales.

FIGS. 10A to 10D are block diagrams showing safe values Sv and changes in heating conditions. FIG. 10(A) shows a case where the safe value Sv is "105" and a calculation result of less than "110" is obtained. The object W could be heat-treated. FIG. 10B shows the case where the safe value Sv is "112" and is more than "110" and less than "113". , it is necessary to review the processing conditions.

FIG. 10C shows the case where the safety value Sv is "115". When the safety value Sv is "113" or more and less than "120", there is a high probability that an abnormal heating will occur. and recalculate the safe value Sv. When the safe value shown in FIG. 10(C) is reached, the rotation speed of the pump 15 is decreased to decrease the flow rate Q, or the preheating temperature is increased by the preheating unit 16 so that the inlet temperature of the Joule heating unit 10 By increasing , the safe value Sv can be lowered to an appropriate range.

FIG. 10(D) shows the case where the safety value Sv is "125", and heating cannot be performed when the safety value is "120" or more. Experimental results show that not only scales adhere and scorching occurs, but also the possibility of damaging the resin cylindrical member 22 is extremely high. In this case as well, the safe value Sv can be kept within the appropriate range by decreasing the flow rate Q by decreasing the rotation speed of the pump 15 or increasing the preheating temperature by the preheating unit 16 to increase the inlet temperature of the Joule heating unit 10. can be lowered to

FIG. 10 shows how to use the safety value Sv when the user heat-processes an object to be heated with specific physical properties using the already assembled Joule heating unit 10 . In this case, since the system elements and physical property values of the Joule heating unit 10 cannot be changed, only the processing conditions are changed and the safe value Sv is recalculated. However, if the number of heating tubes 11 constituting the joule heating unit 10 is increased in advance, and the heating tubes 11 that do not require heating are set as dummies so as not to supply electric power, joule heating can be performed in order to adjust the safety value. The number N of units 10 can also be increased. For example, as shown in FIG. 1, in a joule heating unit 10 having four heating tubes 11, power is supplied to only three heating tubes 11, and the remaining one heating tube 11 is a dummy, that is, is inactive. If the safety value calculated with the number N of 3 is "110" or more, the calculation can be performed again with N set to 4.

Further, the data of the initial correction value K1 shown in FIG. 6 and the data of the final correction value K2 shown in FIG. 7 are stored in the memory of the control unit 31 shown in FIG. The safety value Sv may be calculated by the control unit 31 based on this. In that case, if the safe value Sv is less than "110", the object W to be heated can be heat-treated as it is. However, the safety value may be obtained by the safety value calculation device 40 shown in FIG. If the obtained safe value is less than "110", the processing conditions and the like at that time may be input through the operation panel 32 of the control device 30 to operate the joule heating unit 10 .

When designing and manufacturing the joule heating unit 10 based on the specifications from the user, the system elements constituting the joule heating unit 10 are selected based on the physical properties of the object W to be heated and the processing conditions of the object to be heated. set. The safety value Sv is displayed on the display unit 43 when the safety value calculation device 40 calculates the safety value Sv from the set system elements, the physical property values and the processing conditions requested by the user. The joule heating unit 10 is manufactured so that the safe value Sv does not exceed "113", preferably less than "110". The joule heating unit 10 provided with system elements capable of obtaining this safe value Sv only heat-processes the object to be heated for confirmation, and does not require modification of the system elements. In this way, by using the safety value Sv even in the manufacturing stage, it was possible to manufacture the optimum joule heating unit 10 that does not cause defective heating in a short period of time.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, system elements, physical property values, and processing conditions are not limited to the above-described elements, and further system elements, physical property values, and processing conditions may be added. In addition, even if the safety value for proper heat treatment is changed by adding elements, etc., it is possible to safely heat without causing defective heating based on the safety value. It is possible to determine whether

10 Joule heating unit 11 Heating tube 15 Pump 16 Preheating unit 21 Electrode 22 Cylindrical member 23 Joint 24 Joint 25 Power supply unit 26 Stirring member 27 Stirring shaft 30 Control device 31 Control unit 32 Operation panel 40 Safe value calculator 41 Safe value calculator 42 Input unit 43 Display unit 44 Memory

Claims (6)

A safe value when operating a Joule heating unit that energizes and heats food as an object to be heated while conveying it to a cylindrical member made of an insulating material and a heating tube equipped with a plurality of annular electrodes provided on the cylindrical member. A safety value calculation device for a heating unit that calculates
a system element input unit for inputting system elements of the joule heating unit;
a physical property input unit for inputting the physical property of the object to be heated;
a processing condition input unit for inputting processing conditions of the object to be heated by the Joule heating unit;
a safe value calculation unit that calculates a safe value, which is an indicator of whether or not heating failure will occur, based on the system element, the physical properties, and the processing conditions;
a display unit for displaying the safety value calculated by the safety value calculation unit;has
The processing conditions include the temperature before heating the object to be heated, the temperature after heating, and the flow rate, Safety value calculator for heating units. The safety value calculation device for a heating unit according to claim 1,
The system elements include the inner diameter of the heating tube, the number of sections consisting of one cylindrical member and one electrode combined therewith, the inter-electrode distance between two paired electrodes, and the number of heating tubes. A safety value calculator for a heating unit, including . 3. The heating unit safety value calculation device according to claim 1 or 2,
The physical properties include the viscosity of the object to be heated and whether or not the object to be heated is gelatinized when heated. In the heating unit safety value calculation device according to any one of claims 1 to 3 ,
The safe value calculation unit calculates the safe value from a value obtained based on a logarithm of power density with a base of 1.6. The safety value calculation device for a heating unit according to claim 4 ,
The safety value calculation unit sets a constant value based on the inner diameter of the heating tube and the flow velocity of the heated material as an initial correction value for the heated material that gelatinizes when heated, and the heated material that does not gelatinize even when heated. For objects, the initial correction value is calculated according to the Reynolds number of the object to be heated, and the value obtained by subtracting the initial correction value from the value obtained based on the logarithmic value is set as the safety value. Calculation of the safety value of the heating unit Device. The safety value calculation device for a heating unit according to claim 5 ,
The safety value calculation unit determines a safety value obtained by multiplying the value obtained by subtracting the initial correction value by a final correction value corresponding to the inner diameter of the heating tube.

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