JPS62186183A - Method of bringing primary and secondary product of fibers under predetermined dred state - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for detecting an end point in high frequency drying when primary and secondary fiber products such as rolled cheese, introduced yarn, and textiles are dried to a predetermined moisture content. It is related to.

2. Description of the Related Art Conventionally, Japanese Patent Publication No. 59-53392 is known as a technique for drying fibers such as thread-wound cheese to a predetermined dry state.

This technique involves storing the dyed and dehydrated material to be dried (rolled cheese) in a pressure vessel and sealing it, then reducing the pressure in the pressure vessel and heating the material to be dried. The condensate generated from the dried material flows into a measuring container with a water level gauge and is stored there. When the water level reaches a specified level, a water level detector acts to cut off the flow into the measuring container and drain only the specified amount. The counting operation is repeated to measure the amount of evaporated moisture of the material to be dried, thereby bringing the material to a predetermined dry state.

Problems to be Solved by the Invention However, the conventional technology has the following problems.

Evaporated moisture adheres to the can wall (inner surface of the pressure vessel) and piping, making it impossible to measure accurately and causing variations in the predetermined drying state, resulting in poor measurement accuracy.

Furthermore, since it is necessary to calculate the amount of evaporated water by knowing the initial weight, it is necessary to measure the weight of the dried material after dehydration, which requires extra work.

The present invention was developed with the aim of solving the various problems mentioned above.

Means for Solving the Problem Between Points and Points The method of the present invention for bringing secondary products to a predetermined drying state for textiles is as shown in FIGS. 1 to 3, by high-frequency drying After inserting the material to be dried 1 between the positive and negative electrode plates 3a and 3b provided in the drying chamber A,
The object to be dried 1 is dried by dielectric heating by applying high frequency, and the current value of the high frequency anode current that decreases as the drying state is detected. When the current value reaches a preset current value, the high frequency power source is turned on. It was designed to be cut and then dried.

Example Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

First, the configuration of an embodiment of an apparatus for carrying out the present invention will be described.

As shown in FIGS. 1 and 2, the apparatus for carrying out the present invention has positive and negative electrode plates 3a and 3b spaced apart from each other, and allows the material to be dried 1 to be inserted between the +'J NM treatment 3a and 3b. A depressurizing means B for reducing the pressure inside the drying chamber A is located outside the drying chamber.

+'+jJ Note 111 The heating means C applies the same frequency to the material 1 to be dried 1:1 in the drying chamber A to heat the material 1 to be dried from the inside.

The drying chamber A is equipped with an opening/closing door 2 that seals the interior of the chamber, and is also provided with a cart 4 on which the material to be dried I is placed and inserted between the electrode plates 3a and 3b. In the embodiment of the present invention, as shown in FIG. 2, a negative electrode plate 3b is placed on a trolley 4, and the material to be dried l is placed on it, so that the negative electrode plate 3b is placed below the positive electrode plate 3a provided in the drying chamber A. The negative electrode plate 3b and the electrode plate 3b may be connected to each other.

The pressure reducing means B is connected to a vacuum pump 5 that reduces the pressure inside the drying chamber A through an automatic valve 6, and is connected to the drying chamber A.
A pressure regulator 9 is provided to control the internal pressure.

Note that an automatic drainage valve 7 is installed at a lower position of the drying chamber A to discharge condensate generated by heating and evaporating the material 1 to be dried.

The heating means C includes a high frequency oscillator lO provided outside the drying chamber A and a coaxial 11 provided in the high frequency oscillator.
The material to be dried is connected to the electrodes 12a and 12b through the side surfaces of the drying chamber A, and further to the electrode plates 3a and 3b attached to the top and bottom or left and right sides of the material to be dried 1 inserted into the drying chamber A.
It is designed to heat the mold.

Next, the configuration of an embodiment of a circuit implementing the present invention will be described.

As shown in FIG. 3, the circuit implementing the present invention includes a power supply circuit, a rectifier circuit E, a filter circuit F, an oscillation circuit G, a tuning circuit H, a load circuit J, and an operation circuit. , a high-frequency oscillator 10 with a contact point, and a current meter L (for example, a current sensor, a volt sensor, etc.) are wired so that high-frequency waves can be applied to the object 1 to be dried.

When the power is turned on, the voltage is boosted to generally 10-1:2 KV by the external voltage transformer 14, then rectified by the rectifier circuit E, and supplied to the anode of the oscillation tube 15 to provide high voltage. Then, the oscillation circuit G generates oscillation, and the tuning circuit G1 oscillates.
The device is configured so that the object to be dried 1 can be dielectrically heated by applying a high frequency (generally 3 to 30 MHz) to the load (the object to be dried) in synchronization with the load.

Next, its effect will be explained.

As shown in FIGS. 1 and 2, the material to be dried 1 such as thread-wound cheese, Sohikari, textiles, etc. (here, thread-wound cheese is taken as an example) is placed on a trolley 4 and carried into the drying chamber A, and the electrode plate 3a , 3b, close the door 2, and seal the drying chamber A.

Next, the vacuum pump 5 of the pressure reducing means is operated to reduce the pressure inside the drying chamber A.

Next, when the power is turned on and the electromagnetic contactor Msl shown in Fig. 3 is excited to energize the filament transformer, the setting pointer of the ammeter with contacts of the high frequency oscillator is set to a predetermined value (the predetermined value is the value of the material to be dried). (current value at which the desired moisture content is reached)
Set to .

Then, the electromagnetic contactor M s 2 is excited, and the aforementioned rectifier circuit E, filter circuit F, oscillation circuit G, and tuning circuit I are activated to apply a frequency of 5 to the load (the object to be dried). The material to be dried I is dielectrically heated between the positive and negative electrode plates 3a and 3b.The material to be dried 1 is heated from within by dielectric heating to evaporate moisture.

Here, during this dielectric heating? The amount of heat generated per unit volume is expressed by the following equation.

P = 5/9・E ・tanδ−f −(V/d)x
lo (IJ/Cm) (1) In this equation, ε: dielectric constant of material, f: frequency (II
z/s), tan δ/dielectric constant of material, ■: voltage between electrodes, d: electrode plate spacing, ε/tan δ, dielectric loss.

Here, in the case of the present invention, since f, V, and d are kept constant, when the moisture in the material to be dried 1 evaporates and dries, the dielectric loss (ε・tanδ
) becomes smaller, and as the dielectric loss becomes smaller, the anode current of the high frequency oscillator 1o also decreases.

As it dries, the anode current J decreases, and when it reaches the set value of the contact current 31L of the high frequency oscillator mentioned above, the magnetic contactor Ms2 shown in No. 31J is deenergized, the high frequency power is turned off, and the drying Application of high frequency to object 1 is stopped and drying is completed.

Then, the automatic valve 8 is operated to feed air into the drying chamber A, the door 2 is opened, and the material to be dried 1 is taken out, completing one process.

In addition, in the embodiment of the present invention, a method of drying under reduced pressure has been described, but depending on the object to be dried, drying may be performed under atmospheric pressure, and the pressure is not limited to the pressure inside the drying chamber.

In addition, in the present invention, a method for drying primary and secondary fiber products such as thread-rolled cheese, Sohikari, and textiles has been described. It can also be used in drying technology for wood such as boards.

As described above, according to the present invention, the following effects are achieved.In high-frequency drying of an object to be dried, the object to be dried is inserted between positive and negative electrode plates provided in a drying chamber, and then high frequency is applied to dry the object. The object to be dried is dried by heating, and the current value of the high-frequency anode current, which decreases as the drying state increases, is detected. When the current value reaches the preset setting value, the high-frequency power is turned off.
Since the drying process is completed, the dry state (moisture content state) of the material to be dried can be detected by the current value. Accurate measurements can be made regardless of

Furthermore, even if the amount of evaporated water before drying is not known, the dielectric loss decreases as the drying state progresses, and the high-frequency anode current decreases accordingly. Since the power is turned off, there is no need to calculate the amount of evaporated water or measure the weight after dehydration as in conventional methods, and the drying can be completed at the specified drying state, saving labor. can be expected.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of an apparatus implementing the present invention, and FIG. 2 is a schematic front view of FIG. 1 with the door open. FIG. 3 shows a basic circuit diagram for implementing the present invention. In these figures, A: drying chamber, B: decompression means, C: heating means, and D. Power supply circuit, E: rectifier circuit, F: filter circuit. G: Oscillation circuit, H: Tuning circuit, J: Load circuit, N: Operation circuit, L: Ammeter with contact, l: Object to be dried, 2: Door, 3a
: Positive electrode plate, 3b: Negative electrode plate, 4° trolley, 5. Vacuum pump, 6, 7, 8: Automatic valve, 9: Pressure regulator, 10.
High frequency oscillator, 11/coaxial.

Claims (1)

[Claims] In high-frequency drying of an object to be dried, the object to be dried is inserted between positive and negative electrode plates provided in a drying chamber, and then high frequency is applied to perform dielectric heating to dry the object to be dried, and the temperature decreases as the drying state increases. Detects the current value of high frequency anode current,
When a preset current value is reached, the high frequency power is turned off and the drying process is completed.
A method for bringing secondary products to a specified drying state.