JP6012094B2 - Continuous current interrupting device and arc horn device - Google Patents

Description

  The present invention relates to a continuity interruption device and an arc horn device.

  An arc horn is attached to an insulator device that stretches an electric wire on a steel tower or the like in order to prevent the insulator from being damaged by a flash of lightning or the like and the subsequent continuation arc or the electric wire from being blown out. That is, the arc horn protects the electric wire and the insulator by moving the starting point of the follower arc to a place other than the electric wire and separating the follower arc from the insulator.

  The arc horn is generally disposed on the ground side and the wire side of the insulator device. However, if the arc horn is disposed between the arc horn disposed on the ground side and the arc horn disposed on the wire side, The circuit breaker operates due to the continuation of the current, resulting in a stop accident (power failure) and an instantaneous voltage drop, which hinders power supply. Therefore, a continuity interrupting device that interrupts the continuity has been attached to the arc horn for some time (see, for example, Patent Document 1).

  The continuity interrupting device is configured, for example, by attaching an insulating cylinder to the tip of the ground-side arc horn, and when the arc horn flashes during lightning strikes through the insulating cylinder, the arc By injecting high-pressure gas generated in the insulating cylinder by heat, the follow-up flow is blocked in the insulating cylinder.

JP 2010-34084 A

  By the way, in the continuous current interrupting device described in Patent Document 1, the inner diameter dimension of the insulating cylinder is made different between the arc horn side and the outlet side. By making it larger than the inner diameter dimension on the horn side (back side), the current density in the insulating cylinder during the wake arc generation was reduced, and the blocking performance was improved by suppressing the blockage of the gas flow. .

  However, the continuity interruption device of Patent Document 1 still has room for improvement, such as taking time for interruption of the continuity while performing a water-containing treatment effective in improving the interruption performance.

  Accordingly, the present invention has been made to solve the above-described problems, and can interrupt the continuation in a short time, and can cause a stop accident (power failure) or instantaneous voltage drop due to the continuation. It is an object of the present invention to provide a continuity blocking device and an arc horn device that can be further suppressed.

  In order to solve the above-mentioned problem, the continuity blocking device of the present invention is a continuity blocking device provided with an insulating cylinder 2 in which an electrode distal end portion 11a is inserted and fixed on the base end side, and the insulating tube The body 2 has a through-hole 3 having an electrode-side small-diameter portion 7 and an outlet-side large-diameter portion 8 that is connected to the distal end side of the electrode-side small diameter portion 7 and opens to the distal end surface 9 of the insulating cylinder 2. The inner diameter d2 of the outlet-side large-diameter portion 8 is equal to or less than the appropriate expansion diameter dc that can appropriately expand the gas flow generated in the through-hole 3 by the wake arc, and the appropriate expansion diameter dc. It is characterized by being set to an average value dm or more with the inner diameter dimension d1 of the electrode-side small diameter portion 7.

  Specifically, the ratio of the inner diameter dimension d2 of the outlet-side large-diameter portion 8 to the appropriate expansion diameter dc is set to 0.6 to 1.0.

Moreover, after calculating the pressure of the electrode side small diameter part 7 at the time of the wake arc generation of the through-hole 3, the appropriate expansion diameter dc is calculated using the inner diameter dimension d2 of the outlet side large diameter part 8 as a temporary value.
(A) A procedure for inputting the calculated pressure into Equation 1 and calculating an inner diameter d2 of the outlet-side large-diameter portion 8;
(B) The pressure of the electrode-side small-diameter portion 7 at the time of occurrence of a wake arc in the through-hole 3 is calculated with the inner-diameter size d1 of the electrode-side small-diameter portion 7 being constant and the inner-diameter size d2 of the outlet-side large-diameter portion 8 being calculated. And the procedure to
The inner diameter dimension d2 of the outlet-side large-diameter portion 8 obtained by repeating until the pressure value of the electrode-side small-diameter portion 7 converges is characterized.
(Ae: sectional area of the outlet side large diameter part, A: sectional area of the electrode side small diameter part, Pd: pressure at the outlet side large diameter part, P0: pressure at the electrode side small diameter part, γ: specific heat ratio)

  Further, the arc horn device 10 includes the continuity interruption device 1.

  According to the continuity interrupting device of the present invention, the inner diameter dimension of the outlet-side large-diameter portion is equal to or less than the appropriate expansion diameter capable of appropriately expanding the gas flow generated in the through hole by the wake arc, and the appropriate expansion diameter. Since the inner diameter dimension of the outlet side large diameter portion is set to an optimum value for gas discharge, the blockage of the gas flow can be reliably eliminated . In addition, since the gas flow rate can be improved, the continuity can be interrupted in a shorter time. Specifically, if the ratio of the inner diameter dimension of the outlet-side large-diameter portion to the appropriate expansion diameter is 0.6 to 1.0, a through-hole shape suitable for blocking the continuity can be obtained.

  In addition, by providing the above-mentioned continuity interruption device in the arc horn device, the continuity generated in the arc horn can be interrupted, and the occurrence of a stop accident (power failure) or instantaneous voltage drop due to the continuity can be suppressed. Can do.

It is sectional drawing which shows the continuous flow interruption | blocking apparatus of this invention. It is a simplification figure which shows the attachment state to the insulator apparatus of a continuity interruption apparatus. It is sectional drawing which shows the subsequent flow interruption | blocking apparatus of different embodiment.

  Next, an embodiment of a continuity blocking device of the present invention will be described in detail based on the drawings. FIG. 1 shows a cross-sectional view of a main part of a continuity interrupting device 1 according to the present invention. The continuity interrupting device 1 includes an insulating cylinder 2. Further, as shown in FIG. 2, the insulating cylindrical body 2 is attached to the ground side arc horn 11 of the arc horn apparatus 10 including a ground side arc horn 11 and a line side arc horn 12.

  As shown in FIG. 1, the insulative cylinder 2 has a through hole 3 including a screw hole 4 on the base end side, a small diameter portion 5 on the intermediate portion, and a large diameter portion 6 on the distal end side. Then, by screwing the screw portion of the tip portion (electrode tip portion) 11 a of the ground side arc horn 11 into the screw hole 4, the electrode tip portion 11 a is inserted and fixed to the base end portion side of the insulating cylinder 2. Will be.

  In the state in which the electrode tip portion 11 a is connected, the small diameter portion 5 of the through hole 3 is configured with the electrode side small diameter portion 7 in which the tip edge portion of the electrode tip portion 11 a has a protruding shape, and the large diameter of the through hole 3. An outlet-side large-diameter portion 8 that is connected to the electrode-side small-diameter portion 7 and opens at the distal end surface 9 of the insulating cylinder 2 is formed in the portion 6.

  For example, polyamide resin such as nylon 6 is used for the insulating cylinder 2, and when the arc horn flashes during the lightning strike through the insulating cylinder 2, the inner wall of the insulating cylinder 2 is caused by arc heat. The high pressure gas generated by the ablation is jetted from the outlet side large diameter portion 8 to the outside, so that the continuity is blocked in the insulating cylinder 2.

  The present invention is characterized in that the inner diameter dimension d2 of the outlet-side large-diameter portion 8 is set to an optimum value for improving the blocking performance. Specifically, the inner diameter d2 of the outlet-side large-diameter portion 8 is determined based on an appropriate expansion diameter dc that can appropriately expand the gas flow of the high-pressure gas generated in the through-hole 3 by the continuous arc. There is a feature. Note that proper expansion refers to a phenomenon in which the pressure at the outlet becomes equal to the atmospheric pressure in the vicinity of the outlet. Hereinafter, a method for determining the inner diameter d2 of the outlet-side large-diameter portion 8 will be described in detail.

  In determining the inner diameter d2 of the outlet-side large-diameter portion 8, first, an assumed through hole shape is determined. At this time, the inner diameter dimension d1 of the electrode-side small diameter portion 7, the length dimension L1 of the electrode-side small diameter section 7, and the length dimension L2 of the outlet-side large diameter section 8 are actual dimensions, and the outlet-side large diameter section 8 is used. Only the inner diameter dimension d2 is assumed. As the assumed value of the inner diameter dimension d2 of the outlet side large diameter portion 8, for example, a value 1.5 times the inner diameter dimension d1 of the electrode side small diameter section 7 is used.

  Next, the pressure of the electrode-side small-diameter portion 7 when the continuation arc is generated in the insulating cylindrical body 2 having the assumed through hole shape is calculated (estimated) by CFD (Computational Fluid Dynamics) analysis. Specifically, CFD analysis is performed using the assumed hole shape, arc power at the time of wake arc generation, arc power addition position, gas property value, material specific gravity, etc. as input conditions, The pressure of the electrode-side small diameter portion 7 when the gas pressure at the boundary between the diameter portion 8 and the outside becomes atmospheric pressure (about 0.1 MPa) is calculated.

  Thereafter, (a) the calculated pressure of the electrode-side small-diameter portion 7 is input to Equation 1, which is a design equation of the Laval nozzle, and the inner diameter dimension d2 of the outlet-side large-diameter portion 8 is calculated. Note that γ in Equation 1 is a specific heat ratio, and a value calculated from Equation 2 based on the steady specific heat and mass density obtained by thermal fluid analysis is used. Pd is atmospheric pressure. Further, the inner diameter d2 of the outlet-side large-diameter portion 8 is obtained by converting the large-diameter cross-sectional area Ae of Formula 1 into a diameter.

(Ae: sectional area of the outlet side large diameter part, A: sectional area of the electrode side small diameter part, Pd: pressure at the outlet side large diameter part, P0: pressure at the electrode side small diameter part, γ: specific heat ratio)

(Γ: specific heat ratio, P: gas pressure, Cp: steady specific heat, ρ: gas density, T: gas temperature)

  Next, (b) a through hole shape in which the inner diameter dimension d2 of the outlet-side large-diameter portion 8 is the calculated value of the above equation 1 while the inner-diameter dimension d1 of the electrode-side small-diameter section 7 is kept constant, the same conditions as above CFD analysis is performed to calculate (estimate) the pressure of the electrode-side small diameter portion 7.

  Then, the above procedures (a) and (b) are repeated until the pressure of the electrode-side small diameter portion 7 converges (until the calculated pressure value and the pressure value calculated immediately before are substantially equal). The inner diameter dimension d2 of the outlet-side large diameter portion 8 is the appropriate expansion diameter dc, and this proper expansion diameter dc is adopted as the inner diameter dimension d2 of the outlet-side large diameter portion 8.

  In addition, in the insulating cylindrical body 2 of the present invention, in the ones shown in Tables 1 to 4, the shape of the through hole causes a step in the connecting portion between the electrode side small diameter portion 7 and the outlet side large diameter portion 8. Each of the electrode side small diameter portion 7 and the outlet side large diameter portion 8 is linear without changing its diameter from the start end to the end end. That is, it does not have a taper part, but it is set as the form which connected the holes from which diameters mutually differ in alignment with an axis. Therefore, the shape is greatly different from that of an actual Laval nozzle, and the volume of the outlet-side large diameter portion 8 is also made larger than that of the actual Laval nozzle.

  Therefore, in order to make the volume substantially the same as the actual Laval nozzle, the average value dm of the appropriate expansion diameter dc and the inner diameter dimension d1 of the electrode-side small diameter section 7 is adopted as the inner diameter dimension d2 of the outlet-side large diameter section 8. Yes. That is, in the present invention, the inner diameter d2 of the outlet-side large-diameter portion 8 is set in the range from the appropriate expansion diameter dc to the average value dm.

[Example]
Hereinafter, the inner diameter dimension d1 of the electrode side small diameter portion 7 is 6 mm, the length dimension L1 of the electrode side small diameter portion 7 is 134 mm, the length dimension L2 of the outlet side large diameter portion 8 is 166 mm, the electrode small diameter portion 7 and the outlet side large diameter. The calculation procedure of the appropriate expansion diameter dc of the through-hole 3 in which the length L of the interruption portion composed of the portion 8 is 300 mm, and the short-circuit current interruption test result at the inner diameter dimension d2 set based on the appropriate expansion diameter dc Will be described in detail.

  First, an assumed through hole shape is set based on the above numerical values. Except for the inner diameter d2 of the outlet side large diameter portion 8, the inner diameter dimension d1 of the electrode side small diameter portion 7, the length dimension L1 of the electrode side small diameter portion 7, and the length dimension L2 of the outlet side large diameter portion 8 are actually Use dimensions. In addition, a value (6 × 1.5 = 9 mm) that is 1.5 times the inner diameter dimension d1 of the electrode-side small diameter portion 7 was used as a provisional value of the inner diameter dimension d2 of the outlet-side large diameter section 8.

Next, the assumed hole shape set above, 10 MW as the arc power, the outlet side large diameter portion 8 as the arc power addition position, the air physical property value as the gas physical property value, and the specific gravity of 6 nylon as the material specific gravity 1 .14 g / cm ³ , specific heat ratio γ of 1.2 as input conditions, the internal state of through-hole 3 at the time of wake arc generation was analyzed by CFD analysis, and the pressure at electrode-side small diameter portion 7 was calculated. Note that the arc power of 10 MW assumes a continuation in the power system, specifically, assumes 10 kA applied.

  Then, the procedure of said (a) and (b) was performed until the pressure of the electrode side small diameter part 7 converged, and 19 mm was obtained as an appropriate expansion diameter dc by inputting the pressure into Formula 1.

  Further, in order to make the volume of the outlet side large diameter portion 8 substantially the same as the actual Laval nozzle, the average value dm ((19 + 6) / 2 = the appropriate expansion diameter dc and the inner diameter dimension d1 of the electrode side small diameter portion 7). 12.5 → 13 mm).

  Table 1 shows that in the above-described through-hole 3, the short-circuit current interruption of the inner diameter d2 of the outlet-side large-diameter portion 8 with the appropriate expansion diameter dc (No, 3) and the average value dm (No, 2) The test results are shown. For comparison, the inner diameter dimension d2 of the outlet-side large-diameter portion 8 is assumed to be an assumed value used in the above calculation (No, 1), and the outlet at the initial stage (before convergence) of calculating the appropriate expansion diameter dc The one using the inner diameter d2 of the side large diameter portion 8 (No, 4) is also shown.

  The test conditions are a single-phase direct test, the test frequency is 50 Hz, the test voltage is 69.7 kV, the test current is 5, 10 kA (DC component is zero), and the energization time is 0.08 seconds ( 4 Hz), the transient recovery voltage was a peak value of 138 kV, the rate of increase was 0.75 kV / μs, and the arcing method was blown arc with a copper wire having a diameter of 0.2 mm.

  As shown in Table 1, in No. 3 using the appropriate expansion diameter dc as the inner diameter dimension d2, the interruption was successful in 5 cycles at 0.5 k at 5 kA and 1.5 cycles at 10 kA, and arc transfer at 10 kA. It can be said that the blocking performance is improved as compared with No, 1 and No, 4 which cause Further, in No, 2 using the average value dm as the inner diameter dimension d2, both 5 kA and 10 kA succeeded in shutting down in 0.5 cycles, and the shutting performance is greatly improved compared to No1 and No4. I can say that. The arc transition indicates a state where the arc moves outside the through hole 3 due to the action of interrupting the continuity, and the interruption failure indicates a state where the continuity cannot be interrupted in the through hole 3.

  Next, a short circuit current interruption test result when the interruption portion length dimension L is 225 mm will be described.

  The above method is followed except that the blocking portion length L is 225 mm, the length L1 of the electrode side small diameter portion 7 is 101 mm, and the length L2 of the outlet side large diameter portion 8 is 124 mm. In Table 2, No. 7 indicates that the inner diameter dimension d2 is the appropriate expansion diameter dc, and No. 6 indicates that the inner diameter dimension d2 is the average value dm. In addition, No. 5 has an inner diameter dimension d2 as an assumed value, and No. 8 has an inner diameter dimension d2 as an inner diameter dimension before convergence.

  As shown in Table 2, No. 7 with the inner diameter d2 being the appropriate expansion diameter dc was successfully interrupted in 5 cycles for 1 cycle at 5 kA and 3 cycles at 10 kA, and No, 5 in which arc transfer occurred at 10 kA. Or, it can be said that the blocking performance is improved as compared with No. 8, which has failed to block at 10 kA. Moreover, in No.6 which made the inside diameter dimension d2 the average value dm, both 5kA and 10kA succeeded in interruption | blocking in 0.5 cycle, and interruption | blocking performance improved remarkably compared with No.5 and No.8. It can be said that.

  Thus, it can be seen that the blocking performance can be improved by determining the inner diameter dimension d2 of the outlet-side large-diameter portion 8 based on the design formula of the Laval nozzle. In No, 2, No, 3, No. 6, No. 7, and No. 7 in which the inner diameter dimension d2 is set based on the appropriate expansion diameter dc, the ratio (d2 / dc) of the inner diameter dimension d2 to the appropriate expansion diameter dc is about 0. It can be seen that the inner diameter d2 of No. 2, No. 6 and No. 6 with particularly good results is about 0.6 to about 0.7. The reason why No, 2 and No, 6 were particularly good is that the step formed in the connecting portion between the electrode side small diameter portion 7 and the outlet side large diameter portion 8 is No. 3, 3 or No, 7. This is considered to be because the turbulence caused by the difference in level was suppressed. The ratio (d1 / d2) of the inner diameter dimension d1 of the electrode-side small diameter section 7 to the inner diameter dimension d2 of the outlet-side large diameter section 8 is about 0 for No, 2, No, 3, No, 6, No, 7. 3 to about 0.5, and in No, 2, No, 3, about 0.4 to about 0.5.

  Next, a short-circuit current interruption test result when the inner diameter dimension d1 of the electrode-side small diameter portion 7 is 8 mm will be described.

  The inner diameter dimension d2 is determined in accordance with the above method except that the inner diameter dimension d1 of the electrode side small diameter portion 7 is set to 8 mm. In Table 3, No, 11 and No, 16 are those in which the inner diameter dimension d2 is the appropriate expansion diameter dc, and No, 10, and No, 14 are those in which the inner diameter dimension d2 is the average value dm. Further, No, 9 and No, 13 are assumed to have an inner diameter dimension d2, and No, 12, and No, 17 are inner diameter dimensions d2 to be an inner diameter dimension before convergence.

  As shown in Table 3, it can be said that generally good results have been obtained when the appropriate expansion diameter dc or less (the ratio in Table 3 and the internal diameter d2 / appropriate expansion diameter dc is 1 or less). In No, 10, the blocking at 10 kA failed, but the blocking at 1.5 k was successful at 5 kA, and 2 cycles were required to block 5 kA. It can be said that the shut-off performance is improved as compared with that. In No. 16, both 5 kA and 10 kA have failed to be cut off, but since 10 kA is a failure due to arc transfer, it can be estimated that the transfer path can be blocked if it can be obstructed.

  In the case where the inner diameter dimension d1 of the electrode-side small-diameter portion 7 is 8 mm and the blocking portion length dimension L is 225 mm (No, 13 to No, 17), between the appropriate expansion diameter dc and the average value dm No. 15 is provided, but it can be seen that No. 15 shows the best result. The inner diameter d2 of No. 15 is about 0.8 times the appropriate expansion diameter dc. In view of this result, the inner diameter dimension d2 of the outlet-side large diameter portion 8 with respect to the appropriate expansion diameter dc A good result can be obtained by setting the ratio (d2 / dc) to about 0.6 to about 1.0, and a better result can be obtained by setting the ratio (d2 / dc) to about 0.6 to about 0.8. Is done. Further, the ratio (d1 / d2) of the inner diameter dimension d1 of the electrode-side small diameter section 7 to the inner diameter dimension d2 of the outlet-side large diameter section 8 is about 0.3 to about 0.5, No, 11, No, It can be seen that good results were obtained with No. 14 and No. 15.

  Next, Table 4 shows the short-circuit current interruption test results when the inner diameter d1 of the electrode-side small diameter portion 7 is 16 mm.

  The inner diameter dimension d2 is determined according to the above method except that the inner diameter dimension d1 of the electrode side small diameter portion 7 is set to 16 mm. In Table 4, No. 20 indicates that the inner diameter dimension d2 is the appropriate expansion diameter dc, and No. 19 indicates that the inner diameter dimension d2 is the average value dm. Further, No. 18 has an inner diameter dimension d2 as an assumed value, and No, 21 has an inner diameter dimension d2 as an inner diameter dimension before convergence.

  As shown in Table 4, it can be said that generally good results have been obtained for those having an appropriate expansion diameter dc or less (ratio, inner diameter dimension d2 / appropriate expansion diameter dc is 1 or less in Table 4). In particular, in No, 20, where the inner diameter dimension d2 is the appropriate expansion diameter dc, only 10 kA is blocked, and it can be said that the blocking performance is improved.

  Next, when the shape of the through hole 3 is approximated to a Laval nozzle shape as shown in FIG. 3, specifically, the electrode side small diameter portion 7 side end portion of the outlet side large diameter portion 8 is the electrode side small diameter portion. 7, the opening on the distal end surface 9 side of the outlet-side large-diameter portion 8 is set to an appropriate expansion diameter dc, and the two points are connected by a straight line so as to be tapered toward the distal end surface 9. The result of the short-circuit current interruption test in the case of having been performed will be described.

  In the CFD analysis, the inner diameter dimension d2 is determined according to the above method except that the model shape of the through hole 3 is changed from a stepped shape to a tapered shape. In Table 5, No, 22, No, and 23 all have an inner diameter d2 of an appropriate expansion diameter dc.

  As shown in Table 5, it can be seen that a good result can be obtained by forming the through hole 3 in the shape of a Laval nozzle and setting the inner diameter dimension d2 to an appropriate expansion diameter dc. If the through hole shape is approximated to the Laval nozzle shape, the gas flow rate can be improved as compared with the case where the through hole shape is a stepped shape.

  As described above, in the continuity interrupting device 1 according to the present invention, the inner diameter d2 of the outlet-side large-diameter portion 8 is determined based on the design formula of the Laval nozzle, that is, the outlet-side large The inner diameter dimension d2 of the diameter portion 8 is equal to or smaller than the appropriate expansion diameter dc capable of appropriately expanding the gas flow generated in the through-hole 3 by the follower arc, and the appropriate expansion diameter dc and the inner diameter dimension of the electrode-side small diameter portion 7 are. Since the average value dm of d1 is not less than the average value dm, that is, the inner diameter dimension d2 of the outlet-side large-diameter portion 8 is an optimum value for gas discharge, the blockage of the gas flow can be eliminated. In addition, since the gas flow rate can be improved, the continuity can be interrupted in a shorter time.

  In particular, by setting the ratio of the inner diameter dimension d2 of the outlet-side large-diameter portion 8 to the appropriate expansion diameter dc to be about 0.6 to about 1.0, the continuity interruption device 1 having good interruption performance can be obtained. it can. Therefore, if the continuity interruption device 1 of the present invention is attached to the arc horn device 10, the continuity interruption can be realized in a shorter time.

  Although specific embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. For example, in the above embodiment, the continuity interruption device 1 is provided on the ground side arc horn 11, but it may be provided on the line side arc horn 12, or the continuity interruption device 1 may be provided on both arc horns. Also good. The through hole shape may be a Laval nozzle shape.

  1 .... Continuous current blocking device, 2 .... Insulating cylinder, 3 .... Through hole, 7 .... Electrode side small diameter part, 8 .... Exit side large diameter part, 11a ... Electrode tip part, d1, ... electrode Inner diameter of the small diameter part on the side, d2 .. Inner diameter of the large diameter part on the outlet side, dc ..Appropriate expansion diameter, dm.

Claims (4)

  A continuity blocking device provided with an insulating cylinder (2) into which an electrode tip (11a) is inserted and fixed on the base end side, wherein the insulating cylinder (2) includes an electrode-side small diameter portion (7). ) And an outlet-side large-diameter portion (8) connected to the distal end side of the electrode-side small-diameter portion (7) and opening at the distal end surface (9) of the insulating cylinder (2) (3) Is established, and the inner diameter dimension (d2) of the outlet-side large-diameter portion (8) has an appropriate expansion diameter (dc) capable of appropriately expanding the gas flow generated in the through-hole (3) by the continuation arc. A continuity interrupting device characterized by being equal to or greater than an average value (dm) of the appropriate expansion diameter (dc) and the inner diameter dimension (d1) of the electrode-side small diameter portion (7).   2. The continuity cutoff according to claim 1, wherein a ratio of an inner diameter dimension (d2) of the outlet-side large-diameter portion (8) to the appropriate expansion diameter (dc) is 0.6 to 1.0. apparatus. The appropriate expansion diameter (dc) is a value between the outlet-side large-diameter portion and the outside when the wake arc is generated in the through-hole (3), where the inner-diameter dimension (d2) of the outlet-side large-diameter portion (8) is a temporary value . After calculating the pressure of the electrode side small diameter portion (7) when the gas pressure at the boundary is atmospheric pressure,
(A) A procedure for inputting the calculated pressure into Equation 1 and calculating an inner diameter dimension (d2) of the outlet-side large-diameter portion (8);
(B) When a follow-up arc is generated in the through hole (3) with the inner diameter dimension (d1) of the electrode-side small diameter section (7) being constant and the inner diameter dimension (d2) of the outlet-side large diameter section (8) being calculated. Calculating the pressure of the electrode side small diameter portion (7) of
The continuation according to claim 1 or 2, wherein the inner diameter dimension (d2) of the outlet-side large-diameter portion (8) obtained by repeating until the pressure value of the electrode-side small-diameter portion (7) converges. Flow breaker.
  An arc horn device comprising the continuity blocking device according to any one of claims 1 to 3.