JPS6059612A - Method of heating enameled wire baking furnace - 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] [Technical Field of the Invention] The present invention relates to a method for increasing the temperature of an enameled wire baking furnace, and in particular,
The method of raising the temperature of the hot air circulation type enamelled wire baking furnace is closely related.

[Technical Background of the Invention] A hot air circulation type enamelled wire burning furnace has been known for producing insulated wires for use in electric motors, etc. by baking insulating paint on copper wires, aluminum wires, etc. There is. In this baking furnace, as shown in Fig. 1, a wire 4 runs from a wire entrance 2 of a wire running path 1 in the direction of a dose of 1 part: 1, and the wire is coated in advance. ) The solvent evaporation of the varnish (for example, ester-based, or formalin-based resin) is
Combustion gas (for example, butane) 9 supplied from a gas damper (switch) 5 is combusted to a high temperature by a burner 9a 1, combusted by a catalyst 6, and a blower 7 blows the high-temperature gas to a gas circulation path including a travel path 1. There are four shield rings inside in the direction of the arrows in the figure.

In this furnace, the air 8 supply pan (therefore,
In addition to the gas damper 5 which adjusts the supply plate of the gas 9 supplied according to the amount of air, dampers are provided at various locations. That is, the exhaust damper 10 provided at the upper part of the furnace body adjusts the amount of exhaust gas exhausted from the furnace body.

A pressure chamber damper 11 forms a pressure chamber and seals hot air from the furnace body. The damper 13 is a bypass damper that sends hot air directly to the upper part of the evaporation zone EZ. Further, 14 is a branch damper that separates hot air into the hardening zone CZ and the evaporation zone EZ, which changes the air volume in the hardening zone and the evaporation zone, which affects the baking degree of the baking line.

By adjusting the opening degrees of these dampers 5.10.11.13.14, the optimum temperature distribution is given to the evaporation zone IEZ and the hardening zone CZ, and the degree of C adhesion of the varnish applied to the wire is determined. can do.

In order to measure such temperature distribution, temperature detection points consisting of humidity sensors such as thermocouples are provided at various locations in the furnace body. That is, measurement point 16 before the hot air is divided into the hardening zone and evaporation (IX-), measurement point 17 at the confluence of the hot air blowing from the furnace body and the cold air from the damper 11, measurement point 18 in the middle of the hardening zone, and evaporation. Measurement point 19 is on the upper part of the band, and measurement point 20 is on the lower part of the evaporation part.

In general, one furnace burns various types of wires with wire diameters of 0.6 and 2 wires. For example 10
As many as 70 sets of electric wires are fired (-J) at the same time, but they are naturally influenced by the furnace in the corner, and the steady supply of gas also varies depending on the wire diameter and the type of varnish.

Under these circumstances, the work of setting the temperature distribution of the furnace during temperature rise consumes valuable time to ensure reproducibility.

That is, the temperature rise of the furnace is particularly as shown in FIG.
Fixing the air damper 10 and the pressure chamber damper 11,
The gas damper 5 was controlled so that the representative furnace temperature (temperature at the measurement point 1G) inside the furnace body reached a set temperature X at which the varnish could be baked.

When such a temperature increase is performed, air leakage ff1 (including the intake amount of outside air) from the pressure chamber section (11) and the line inlet section 2 occurs due to changes in the draft accompanying the temperature rise inside the furnace. changes slightly. Furthermore, in order to prevent hot air from escaping as much as possible from the viewpoint of energy conservation, if the pressure chamber damper 11 is opened to increase the pressure effect, or the exhaust damper 10 is left slightly closed, the above-mentioned draft change can be avoided. Circulating air inside the furnace blows out from the wire inlet 2, staining the varnish applicator (not shown) located directly below, which causes bongs and wire breaks, and has a serious impact on quality and workability. In order to prevent this, the pressure chamber damper 11 and the exhaust damper 10 are set so that the opening degrees are adjusted to the safety side, which causes energy loss and a prolonged temperature raising operation.

[Objective of the Invention] The present invention has been made to solve the above-mentioned problems of the conventional technology. Sometimes it reduces energy loss.

There is a document C that attempts to provide a heating method for a hot air circulation type enamelled wire burning furnace that can shorten the heating time.

[Preferred Embodiments of the Invention] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

First, in this embodiment, each damper 5.10 shown in FIG.
．． 11, I3.14 is very good, (system chipping motor M5, MIOlMl ], M]3, its opening degree is adjusted by M14, and point 16.17.18.19.20
A humidity sensor, such as a thermocouple, is installed in the Each Stellar Pink motor receives an input signal (shown as a solid line) and generates an output signal (shown as a dotted line). Each temperature sensor also generates an output signal. These signals are A/D converted by the I10 controller 1-roller 25 and sent to the C
PU26 (Heuret I-Patsu Card Co., Ltd. tl P 1
000M series), and the signals calculated and controlled there are again D/A converted by the controller 25 and applied to the stepping motors of each damper.

Next, a method of organically PID controlling such a damper to raise the temperature of the furnace will be described.

As shown in FIG. 2(b), the opening degree of the gas damper 5 is
PT so that the representative furnace temperature (temperature at measurement point 16) in the furnace body becomes the set temperature Y (for example, 460°C) that allows varnish application.
D is controlled. For this control, the temperature at the measurement point 16 is input to the CPU 26 and compared with the set temperature Y, and an output signal drives the stepping motor M5 to adjust the opening degree of the damper 5 in accordance with the result. An example thereof is shown by curve 5 in FIG. 2(b). In addition, the set temperature mentioned in 2.2.
6 is automatically set.

The opening degree of the exhaust damper 10 is PID-controlled according to the opening degree of the gas damper 5 so that an amount of exhaust gas corresponding to the amount of gas combustion sent into the furnace body by the burner 9a is exhausted. For this control, the CPtJ26 calculates the combustion amount of gas being sent into the furnace by the burner 9a from the gas damper opening, and the CPU 26 controls the exhaust gas to exhaust the amount of exhaust gas corresponding to the gas combustion amount. The opening degree of the damper 10 is calculated, and the result is output as a control signal for the stepping motor MIO, which drives the damper 10 and adjusts its opening degree. An example of this is shown by curve 10 in FIG. 2(b). In addition, the relationship between the opening degree of the gas damper, the amount of gas burned, and the exhaust damper and the exhaust ■ should be measured in advance.
CPU 2 (store the relational expression in i).

The opening degree of the pressure chamber damper 11 varies from the opening degree at normal temperature to the opening degree at temperatures A and f as the representative furnace ρ increases, and varies from 1 to rough 1- in response to or in proportion to the furnace temperature. Adjust to the optimal value to suppress. As mentioned above, while the gas damper 5 is almost fully open (100%), the exhaust damper JO is at a constant opening as shown in the double series, so the trough 1 condition is also constant.
The opening degree of the pressure chamber damper is controlled according to the furnace temperature, and the opening degree of the pressure chamber damper is controlled according to the furnace temperature until the gas damper 5 starts to close and the furnace temperature reaches a set value Y. An example of this is shown by curve 11 in FIG. 2(b). Note that since the amount of trough 1 differs depending on the furnace structure, pressure chamber configuration, and finished state, the relationship between the furnace temperature and the pressure chamber damper opening degree is actually measured and the relational expression is calculated by the CPU.
26 to be memorized. In this case, since the trough effect in the pressure chamber is greater when the temperature rises than at room temperature, it is preferable to control the pressure chamber damper in a direction that weakens the pressure effect when the temperature rises from room temperature. .

Further, the opening degrees of the other dampers, that is, the bypass damper 13 and the branch damper 14 may be fixed;
I) TD control can also be performed by correlating with the opening degree of the damper 5.10.11 mentioned above or the furnace temperature.

Gas damper 5, exhaust damper 10, pressure chamber damper 1
By controlling 1 as described above, each damper acts organically as shown in FIG. 2(b), the heating time is significantly shortened, and energy loss is reduced. According to experiments, the heating time is 30% shorter than the conventional heating time shown in Figure 2 (,).
% time is reduced.

[Effects of the Invention] As is clear from the above examples, hot air according to the present invention!
#By using a separate method for the annular enamelled wire baking furnace, the gas damper, exhaust damper, and pressure chamber damper are organically controlled, reducing energy loss during temperature rise and making temperature rise work easier. Can be shortened.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a hot air circulation type enameled wire baking furnace used in the present invention and its control system, and FIGS. 2(a) and (b) are graphs showing the conventional temperature raising method and the present invention, respectively. 1......Travel path 4...Electric wire 6...Catalyst 7...Blower 9a... Burner 5... Gas damper 10... Exhaust damper 11... Pressure chamber damper agent Patent attorney Moritani - Figure 1 Figure 2

Claims (1)

[Claims] A running path for electric wires formed in a furnace body, a burner for burning combustion gas, and a solvent evaporated portion of varnish applied to the electric wires in advance is burned at a high temperature by the burner. a catalyst, a blower that circulates the high-temperature gas thus formed into a gas circulation path including the travel path, a gas damper that adjusts the supply amount of the combustion gas, and an amount that adjusts the amount of exhaust gas exhausted from the furnace body. When raising the temperature of a hot air circulation type enameled wire baking furnace that is equipped with an exhaust damper and a pressure chamber damper that seals hot air from the furnace body, the opening degree of the gas damper is set to a temperature that is representative of the furnace temperature inside the furnace body and allows varnish baking. When the temperature is controlled to reach a set temperature, the opening degree of the exhaust damper is adjusted according to the opening degree of the gas damper to exhaust the amount of gas corresponding to the gas combustion claw sent into the furnace body by the burner. The opening degree of the pressure chamber damper is controlled as follows, and the opening degree of the pressure chamber damper is adjusted as the furnace temperature increases. 1. A method for increasing the temperature of a hot air circulation type enameled wire baking furnace, characterized in that the temperature is controlled between the opening degree and the temperature in accordance with the furnace temperature.