DE2047661A1 - insulator - Google Patents

Description

Dr. F. Zumsteln sen. - Dr. E. Assmann Dr. R. Koenigsberger - Dlpl.-Phys. R. Holzbauer - Dr. F. Zumsteln Jun.

PATENT LAWYERS TELEPHONE: COLLECTIVE NO. 225341

TELEX 529979

TELEGRAMS: ZUMPAT CHECK ACCOUNT: MUNICH 91139

BANK ACCOUNT: BANK H. HOUSES

8 MUNICH S,

BRAUHAUSSTRASSE 4 / III

Case 45509-12

TOKYO ELECTRIC POWER CO., LTD., TOKYO / JAPAN TOKYO SHIBAURA ELECTRIC CO., LTD., KAWASAKI-SHI / JAPAN

insulator

The invention relates to an insulator for lines λ power transmission, in particular a-strengthened glass insulator with excellent creep resistance.

Insulators for power transmission lines do exist mainly made of porcelain, but also those made of glass are known. One of the known methods of manufacture Solidified glass insulators consists in the fact that a molten mixture, for example, of a glass mass with the chemical composition given in Table 1 and the physical properties given in Table 2 is formed into an insulating body of the desired shape,

1098U / 1963

and that the insulating body is then quenched by blowing air in order to generate compressive stress in it.

Table 1

sample SiO 2 Al 2 ° 3 Fe 2 ° 3 Well ₂ I.
O ^K 2 O HgO CaO BaO SO ₃ 5 A. 68. 0 4th .0 0 .5 10 .5 3 , 5 3.5 6.0 3.5 0. 5 B. 72. Q 2 .0 - 13th .5 1 .0 4.0 7.0 - 0.

Table 2

sample Expansion
coefficient
X ⁰ C- ¹ ) Transition
Point
( ⁰ C) Tg Flow
border
( ⁰ C) Tc Expansion
chungsp.
( ⁰ C) Ts Ts ² / * C
(° c ³ ) A. 92x10 ~ ⁷ 530 630 747 6100 χ 10 ⁷ B. 93 χ 10 ~ " ⁷ 520 620 731 5800 χ 10 ⁷

Aufler according to the aforementioned conventional quenching process (Glass treated according to this process is known as tempered or tempered glass), solidified glass objects can can also be made by placing a shaped article in a bath of molten potassium sulfate with is immersed at a temperature lower than that

10981 4/1953

Transition point of the glass. This replaces the sodium ion on the glass surface with a potassium ion. Further, a method is known in which a glass article is treated at temperatures of two or three hours, which lie between the transition point and the softening point of the article, and is formed in which on the surface a crystal layer so as to solidify the article. Although the following description is restricted to insulators made of tempered glass, it should be pointed out that the present invention can be applied to any type of said strengthened glass insulator.

Solidified glass insulators outperform porcelain insulators in terms of their physical-electrical properties, such as tensile strength, dielectric losses as a function of temperature, arc current as a function of time, dielectric strength in oil and with regard to properties in the event of thermal shock. Furthermore, the glass insulator is lighter than the porcelain insulator, namely its weight is only about 2/3 the weight of the latter. Tempered glass insulators have the advantage that if cracks occur in the insulator, they immediately spread over the entire body and it shatters into fine splinters. This phenomenon has not yet been observed with porcelain insulators. In the event of atmospheric discharges, the porcelain insulator retains its shape even though the body is broken, so that it often holds itself on a power transmission line. It is therefore difficult to determine from a distance whether a porcelain insulator is actually in such a condition If, on the other hand, a solidified glass insulator tears by a lightning strike, it immediately breaks into pieces and is thrown away, so that the detection of a destroyed insulator is made easier. With regard to the insulator monitoring, insulators made of tempered glass are extremely useful.

10981 A / 1953

insulator is also less expensive than the porcelain insulator.

While the tempered glass insulator in the aforementioned Way is superior to that made of porcelain, but it has a less satisfactory creep resistance than that latter. "Creep" here means a phenomenon in which the affected insulator surface is contaminated Place a red point of light appearing as a result of a leakage current, so that the surface is destroyed by erosion. This phenomenon is favored when the insulator surface is polluted by saline substances, so that it was previously difficult, for example in coastal areas, according to known Method to use insulators made of solidified glass.

It is therefore an object of the present invention to provide a strengthened glass insulator, its Creep resistance is equal to or better than that of porcelain insulators, without the excellent properties give up previously known insulators made of solidified glass. Furthermore, the glass insulator according to the invention should be inexpensive and, for example in coastal areas, should be of superior quality exhibit.

The strengthened glass insulator according to the invention is made from a glass mass which fulfills the following three conditions:
A) The proportions of the constituents of the glass mass are in the following range:

Wt%

SiO _{2 30-80}

Al ₂ O ₃ 0-40

CaO 0-40

MgO 0-40

BaO 0-20

Al ₂ O ₃ + CaO 1-69

1 0 9 8 1 U 1 9 5 3

Wt%

Al ₂ O ₃ + CaO + MgO + BaO 5-69

Na ₂ O 0-5

K ₂ O 0-10

Na ₂ O + K ₂ O 0-10

Li ₂ O 0-10

B ₃ O ₃ 0-40

ZnO 0-30

PbO 0-10

Fe ₂ O ₃ 0-5

B ₂ O ₃ + ZnO + PbO + Fe ₃ O ₃ "0 * ■ 60

+ Bi
PbO

Na ₂ O + K ₃ O + Li ₂ O + Ba ₃ O ₃ + ZnO

(B) The softening point is between 800 and 1200 ⁰ C; and

(C) The value of the ratio

^ Softening point ( C) J.

[mean linear expansion coefficient! I at temperatures from 100 to 300 C ₍ o _r -l

lies between 8000 χ 10 ⁷ and 30,000 χ 10 ⁷ ( ⁰ C ³ ).

The invention is explained in more detail below with reference to the accompanying drawing voltage. Show it: '

Fig. 1 is a partially sectioned view of a creep resistance test used solidified glad.solators;

Fig. 2 is a schematic representation of a creep strength tester;

3 shows a schematic representation of FIG. 5 during creep strength tests patterns of destruction or damage caused;

1098U / 1953

4 shows in a diagram using an example the extent of the destruction as a function of the physical properties of the insulating glass; and

FIG. 5 shows a diagram similar to FIG. 4 in a further example

The chemical constituents and the values of the physical properties of the glass composition according to the invention for production Solidified glass insulators whose creep resistance is equal to or higher than that of porcelain insulators are made of limited to the above-mentioned ranges for the following reasons.

If less than 30% SiO is added, the creep resistance is not improved regardless of the proportions of the other components. At more than 80% SiOp there are considerable difficulties in melting the resulting glass, since no homogeneous mass is obtained. The presence of AlpO. ,, CaO, MgO and BaO contributes to increasing the creep strength. However, if the AlpO ₃ content rises above 40%, it becomes difficult to melt the glass. _{If the AlpO 3} content is less than 15%, the glass quality is not good. With more than 40% CaO or MgO, the devitrification property of the glass increases considerably, so that the quality of the glass is not good. If more than 20% BaO is added, difficulties arise in melting the glass. If the proportion of AIPO ₃ and CaO together less than 1% or greater than 69%, or the content of AIPO _3, CaO, MgO and BaO is in total less than 5% or higher than 69%, so a decreased creep resistance is the result . The melting of the glass is promoted by adding Na-O, KpO or Li-O. However, if the content of any of these components exceeds the above range, the creep resistance and electrical properties are unduly deteriorated. It should be particularly noted that considerably more than 10% Na ₃ O and K ₂ O, the creep _"f

1098U / 1953

is worsened. If more than 40% B2 ° 3, the creep resistance and mechanical strength are deteriorated. When adding ZnO, PbO or Fe ^ O ₃ , melting of the glass is facilitated. However, if the content of any of these components increases beyond the above-mentioned range, the creep resistance decreases very sharply. If more than 60% BpO, ZnO, PbO and Fe ₂ O- together are used, the creep strength deteriorates. Does the total amount of Na fall _? 0, K ^ O, IrI ₂ O ₃ , B ₃ O ₃ , ZnO, PbO and Fe _? O less than 1%, it is difficult to melt the glass. If the aforementioned total content rises above 60%, the creep resistance decreases. For safety's sake may hinzuge- less than 1% As or Sb 0. O ₅ as a refining agent g

will give.

The values of the chemical components of an insulator glass have been given from the standpoint of required properties. It has been found, however, that an improvement in the creep resistance of glass insulators cannot be reliably achieved by simply limiting the components to be used in the above range, but that the creep resistance is largely influenced by the physical properties of the insulator. As has been seen from a number of experiments, there is a close relationship between the creep resistance of a glass insulator and the value of Ts / cC. Here, Ts and ^ C are the softening point ( ⁰ C) or the mean linear expansion coefficient of the insulator at temperatures between 100 and 300 ⁰ C. So that the creep strength of the solidified glass insulator is equal to or higher than that of porcelain insulators, the glass composition must be chosen so that the ratio Ts / $ C of the glass ^{exceeds a value of 8000 χ 10 (0} C). However, if the insulator is made of a glass composition in which the ratio of Ts / «C ^{rises above 30,000 χ ΙΟ 7} , it becomes difficult to melt and shape the glass, resulting in a deterioration in creep resistance. If the value of Ts / <C is within the above

1098U / 1953

mentioned range, but the softening point of the same is lower than 800 ° C., the creep resistance assumes an unsatisfactory value as in the case of known solidified glass insulators. A softening point above 1200 ⁰ C to give SchwJe culties in melting and forming of the glass.

It has also been found that the addition of further additives within the range mentioned below in addition to the above-mentioned ingredients promotes the creep resistance »

Content range (w _o -%)

^Zr0 2 0 - 10

TiO _{2 0-20}

BeO 0-25

ZrO ₂ + TiO ₂ + BeO 0.2-40

ZrO ₂ , TiO ₂ and BeO each contribute to increasing the creep strength. However, if the content of ZrO or TiO ₂ rises above 10 or 20%, difficulties arise in melting the resulting glass and it is very easily devitrified. At more than 25% BeO, the glass produced is no longer transparent. With less than a total of 0.2% ZrO_, TiO _? and BeO, an increase in creep resistance is prevented. If the total content rises above 40%, the glass becomes difficult to melt and the creep resistance drops.

_{Small amounts of F, P 2} ° 5> ^Bi 2 ° 3 'SrO, V ₂ O ₁ -, MoO ₃ , W0 _gf CdO or oxides can be used in any case to favor melting of the glass or to prevent its devitrification or to reduce its creep resistance rare earths are added. Furthermore, without impairing the creep

1098U / 1953

_ 9 -

strength small amounts of conventional glass coloring agents can be added, for example Fe, Mn, Co, Ni, Cr, Cu, U, Nd, Au, Ag, or oxides or sulfides thereof.

The invention is to be explained in more detail with the aid of the following examples. 4 and 5 are the glass components given in weight ratio.

example 1

Appropriate amounts of the following starting materials were used; Ä

Quartz sand, aluminum hydroxide, activated aluminum oxide, feldspar, iron oxide, boric acid, anhydrous soda, potassium carbonate, ^ Barium carbonate, lead oxide, zinc oxide, lithium carbonate, lepidolite, antimony oxide and arsenic acid.

In this way, the mixed Oxydzusammensetzungen used in the experiments shown in Table 3 · The starting materials were mixed and melted in a game at a temperature of 1500-1650 ⁰ C. A predetermined amount of uniformly melted and cleared glass was withdrawn. A required number of standard suspension insulators with a diameter of 25 cm were produced. Each glass insulator body was quenched uniformly to a Λ temperature that was slightly lower than the pour point of the glass, ie the temperature at which the deformation begins under its own weight. Compressed air at room temperature was blown onto the surface of the body to carry out the tempering, and the necessary metal parts were then attached to complete a solidified glass insulator. The creep resistance test was then carried out.

109814/1953

ORIGINAL INSPECTED

Fig. 1 shows the structure of a glass insulator subjected to the test. On the underside of a glass body 1 with a flat cap 2 and an upper projection 3, three round webs 4a, 4b and 4c are formed concentrically to the edge 5 of the cap 2. A metal cap 6 of the crevice type is attached over the upper projection 3 by means of an adhesive 7. At the center of the inner wall of the glass body 1, a recess 8 is provided, in which the upper half of a metal pin 9 is embedded. The glass body 1 and the metal pin 9 are connected to one another by a further adhesive 10. The upper part of the metal cap 6 and the lower end of the metal pin 9 are provided with split pin openings and 12, respectively.

To carry out the creep resistance test, part of the Dirty surface of the described insulator. The pollution material consisted of a mixture of 10 parts by weight of abrasive powder, one part by weight of carbon powder and 7 parts by weight synthetic glue. This mixture was on the flat cap 2 of the insulator 1 in the form of a Tape of 10 mm / unü 1 mm thickness applied so that it extended in a direction that connects the metal cap 6 and the metal pin 9 on the shortest path. Further was on the surface of a groove between the webs 4a and 4b or 4b and 4c on the inside of the cap 2, the was coated with a tape made of the pollution mixture, applied water-repellent silicone oil.

The insulator prepared in this way was tested for its creep resistance in a device, the working principle of which is shown schematically in FIG . According to FIG. 2 , a metal cap 22 of a test insulator 21 is connected by a split pin 25 to the metal pin 24 of a further insulator 23 and from the top wall of a sealed test chamber 28

1098U / 1953

ORIGINAL INSPECTED

suspended by a cord 27 of insulating material attached to the metal cap 26. The metal pin 30 of the Test insulator 21 is connected to one output terminal 32 of an external test transformer via a conductor 33. The other output terminal 34 of the transformer is grounded. The gap-type metal cap 22 of the trial insulator 21 is connected via a conductor 36 and a variable resistor 37 to an external pen oscilloscope 35, the end of a line connecting the oscilloscope 35 and the resistor 37 is grounded. Of the variable resistor 37 is used to adjust the size of the current flowing through the coil of the oscilloscope 35. The test insulator 21 is arranged in such a way that it can be sprayed with water at an angle from below by means of a spray nozzle 39 can, which is arranged at the bottom 38 of the test chamber 28.

The test was carried out in the following manner. An alternating voltage of 25 kV was applied to the test insulator 21 via the output terminal 32 of the transformer 31 is pressed. The sample isolator was moistened with tap water flowing through the spray nozzles 39 was sprayed in amounts corresponding to a rainfall of 5 mm per minute. During the trial isolator was held in this state, the electric leakage current was measured by means of the oscilloscope 35, which on the Surface of the sample insulator 21 occurred. Two hours after the start of the test, the test insulator 21 was removed from the test chamber 28 taken out. The measure of destruction was then determined with the naked eye the surface of the sample insulator 21 is observed.

3 shows 5 stages of destruction of the test insulator 21. In In picture I the insulator is only slightly damaged, which indicates that the creep resistance is completely satisfactory. In panel V the damage is most severe, indicating that the creep resistance is the lowest. The pictures II, III and IV show intermediate stages of damage between the

1098U / 1953

Figures I and V, which have been divided into three levels for the sake of simplicity. That means that the creep resistance gradually decreases in the series of three stages. As measured by these five levels, a porcelain insulator generally exhibits a damage according to pictures I or II, while a glass insulator of conventional type to the extent of image V is destroyed.

A large number of tempered glass insulators with different compositions and physical properties have been used Properties as listed in Table 3 were tested. The evaluation of the creep resistance was made accordingly the severity of the destruction according to FIG. 3 evaluated. The underlined test numbers identify control samples that were made of glass compositions which did not fully satisfy the above three conditions. How yourself from Table 3, are in the isolators according to the invention the measured values of creep resistance as for porcelain insulators according to Figures I or II of Fig. 3. On the other hand, the values correspond to the creep strength of insulators whose glass composition did not meet the three conditions, Figs. III, IV or V.

For comparison it should be mentioned that the breakdown voltage resp. Flashover voltage in oil from conventional insulators tempered glass is around 120 kV and that of porcelain insulators is around 158 kV. During the trials of the In Table 3, the breakdown voltage was also measured on typical samples. The results are also in the table listed. As can be seen from this table, the present invention can reduce the breakdown voltage in oil of an insulator made of tempered glass is increased to the breakdown voltage of a porcelain insulator or higher will.

109814/1953

Table 3

- 13 -

Test results

Attempt no. 1 2 I. 3 • 53 4th II 5 6th 7th 8th Chemical
Composition 750 SiO ₂ 74 57 59 760 < 54 59 57 55 50 Al ₂ O ₅ 11 18th 19th 95O < 22nd 13th 17th 22nd 19th Fe ₂ O, - - - _. - " _ I ^B 2 ° 3 - 11 - 5 5 3 4th Na ₂ O 4th - 1 1 - 1 1 K ₂ O 5 1 4th 2 . 3 5 2 MgO 3 2 3 4th 8th - 2 CaO 3 5 9 10 9 14th 14th BaO - 6th 5 2 3 2 - 5 Further - - - - - - - 1 Sb ₂ O ₅ 0.4 0.4 0.4 0.4 0.4 0.4 0.4 7th As ₂ O ₅ 0.2 0.2 0.2 0.2 0.2 0.2 0.2 5 Physical
Properties 1: 13th Expansion Sa-
coefficient dC (° C ~ ♦ 62 37 50 52 61 56 - Transitional
( ⁰ C) 650 670 690 690 690 680 - - Yield point 76O < 770 760 760 77O 760 0.4 Softening p . 977 968 933 915 914 910 0.2 Ts ² / * C χ 10 "" ⁷
( ⁰ C ³ ) 153OO 25300 17OOO 174OO 16100 I37OO 14800 Rating d.
Creep resistant I.
C.
I HIIMi I. II I. II 66 ' 660 760 876 11600 I.

1098U / 1963

Attempt no. ■ 9 10 11 12th 13th 14th 15th 16 7 I. 58 Chemical
Coll i
600 SiO ₂ 51 47 44 51 41 50 57 55 720 Al ₀ O, 17th 19th 23 15th 23 17th 15th 12th 807 20th 12th 12th 14th 14th 13th 3 14th 11200 Na ₂ O - - 1 - - 1 - 2 II K ₂ O 1 1 1 1 1 1 - 2 MgO 6th 11 4th 6th 8th 2 10 . 1 CaO 5 10 11 13th 13th 16 9 8th BaO - - 4th - - - 6th 6th Further - - - - - - - - Sb ₂ O ₅ 0 * 4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 As ₂ O ₅ 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Physical
properties Expansion no 38 49 52 52 52 54 58 Transitional 640 670 660 650 670 650 640 Yield point 760 760 760 750 750 750 740 Softening p.
Ts ( ⁶ C) 870 859 853 850 845 841 840 Ts / jpg 10 "" 19900 15000 14000 13900 13700 13100 12400 Rating d.
Creep resistant
speed
Punch through
spg. (kV; "I. I.
160 I. II
158 II II II
158

1098U / 1963

Attempt no. 12th 18th • 30th 12th 20th 21st 52 22nd 73 22nd 24 75 Chemi see
Composition 15th 720 730 730 ^! SiO ₂ 60 10 29 80 81 780 40 790 40 40 790 Al ₀ O, 7th 3 15th 1 - 935 40 940 41 - 930 B ₂ O ₃ 9 5 10 9 9 16800 10 12100 9 10 11500 Na ₂ O 5 10 3 5 5 III 5 I. 5 5 I. K ₂ O 3 20th 5 5 5 5 5 5 - MgO 5 7th 10 - - - - - CaO 6th - 20th - - - - 40 BaO 5 - 7th - - - - - Further - - - - - - - - Sb ₂ O ₅ 0.4 - - - - - - * As ₂ O ₅ 0.2 66 - - - - - - Physical
properties 700 ' Expansion = - 70 780 66 53 75 Transitional
( ⁰ C) 580 920 - 720 - Yield point
( ⁸ C) 690 12800 - 780 - Softening p.
Ts ( ⁰ C) 762 I. - 940 - ^ ⁰ C ³ * • 10900 - - 17500 - Rating d.
Creep strength III Ill I. III Punch through
spg. (kV) - 165 -

1098U / 1963

Attempt no. 40 26th 44 22nd 45 _ 28 70 40 71 _ 30th 64 31 59 30th 58 Chemical
Composition - 715 ... 675 10 675 660 10 660 SiO ₂ - 40 785 40 - 40 745 1 - 45 740 30th 760 1 750 Al ₂ O ₃ 9 1 • 855
16000 - Ill 10 855
10500 15th Ill 10 860
11600 10 840
11900 41 830
11800 Fe ₂ O ₃ 5 - I. - 2 I.
162 - 1 I. 2 I.
Ö65 _ III B ₂ O ₃ 5 9 9 15th 5 15th 40 5 Na ₂ O - 5 5 - ' - - - - κ ₂ ο 41 5 5 5 8th 5 5 8th ■ M ₆ O - 40 41 - 21st ~ - 5 CaO - - - 8th - 8th 8th - BaO - - - 20th - 15th 5 - Further - ■ - - - - - - - Sb ₂ O ₅ - - - - - As ₂ O ₅ _ φ * - - - - Physical
Characteristics:
Expansion «r
coefficient tU ⁰ ^ ¹ ) Transitional
( ⁰ C) - Yield point
<° c5 Ill Softening p.
Ts ( ⁰ C)
Ts ² ZcCx 10 ~ ⁷
( ⁰ C ⁵ ) Rating d.
Creep strength
Punch through
spg. (kV)

1098U / 1953

Attempt no. 33 J4 21st 60 12th 38 12th 6th 3 65 40 57 Chemi see 7th - 660 680 Composition 7th 2 760 750 SiO ₂ 30th 50 50 3 60 60 60 8th 830 60 860 Al ₂ O ₃ 10 10 10 10 7th 7th 7th 3 7th B ₂ O ₃ 15th 14th 12th 2 6th 7th ₂ 010Li ₂ O11 10600 13th I3OOO Na ₂ O 5 6th 8th 8th 3 3 III 3 I. K ₂ O 3 3 3 3 11 - - - - MgO 7th 7th 7th - 2 2 64 2 CaO 8th 5 5 8th 8th 660 8th BaO 5 VJl 5 3 3 760 3 Further - - - 70 - Li 840 Li ₂ O 3 Sb ₂ O ₅ 640 : Physical
properties 720 11000 ExpansionSy 51 63 66 785 74 II Transitional 680 670 650 635 158 Yield point
( ⁸ C) 760 740 720 8800 700 Softening p.
Ts ( ⁰ C) 815 800 780 III 750 Tä / (/ - Of 10 ~ - (C) 12700 10100 9200 7500 Rating d.
Creep strength I. III IV III Punch through
spg. (kV) - - - -

1088U / 1953

ORIGINAL INSPECTED

Attempt no. 41 42 - 45 44 Sl 46 47 48 Chemical - 17 - Assemble 5 SiO ₂ 60 50 - 45 44 44 50 50 50 Al ₂ O ₃ 7th 10 5 10 10 6th 15th 15th 13th Fe ₀ O ₂
<- j - 2 - - - - - - 5 B ₂ O ₃ 5 - 5 5 10 7th 6th Na ₂ O 5 ZnO 25 - - - - - - K ₂ O - 0.4 VJi VJl VJi 5 5 3 MgO 2 0.2 2 2 2 7th 7th 7th CaO 8th 5 5 5 10 10 10 BaO 5 - - - - - - Further Li ₂ O15 55 ZnO 50 ZnO 51 ZnO 55 PbO 5 PbOIO PbO11 Sb ₂ O ₅ 0.4 0.4 0.4 0.4 0.4 0.4 0.4 As ₂ O ₅ 0.2 690 0.2 0.2 0.2 0.2 0.2 0.2 Physical 780 properties Expansion,
koeff.c & V " ¹ ) 64 845 57 58 58 54 58 61 Transitional ( C) 640 I5OOO 670 660 650 670 650 650 Positive limit
( ⁰ C) 740 760 750 740 760 760 750 Softening p I. Ts (C) 855 - 845 825 810 860 850 840 rs / wx 10 " ( ⁰ C ³ ) 10900 125OO 11700 11400 I54OO I25OO 11500 Rating d. Creep strength IV I. III IV II II III Punch through - - - - - 158 -

1098U / 1963

ORIGINAL INSPECTED

Attempt no. Üä 50 55 ^ 2 53 56 55 8 ΐ III Chemical
To put together 10 - 40 < - SiO ₂ 50 6th 55 55 - 30th 5! Al ₂ O ₅ 13th 10 7th 10 0.5 15th 40 14th : Fe ₂ O ₃ - ■ 5 2 8th - 3 - 3 B ₂ O ₅ 4th 7th 3 7th 15th 3 15th - Na ₂ O - 2 · · 8th 2 3 16 1 - K ₂ O 1 3 4th 3 3 - - 30th MgO 7th 8th 5 8th 16 7th - - CaO 10 5 - 2 0.5 - 14th - BaO, - 5 0.4 5 7th 0.4 - 0.4 Further PbO 15 - 0.2 - - 0.2 - 0.2 Sb ₂ O ₅ 0.4 0.4 0.4 0.4 0.4 As ₂ O ₅ 0.2 0.2 52 0.2 0.2 53 0.2 80 Physical shot
Characteristics: 670 mm ExtensionS ^
coefficient <. (TC ~ ^x ) 68 52 760 54 43 - 80 - Transitional period
( ⁰ C) 610 670 850 660 650 705 Yield point
( ⁸ Ci 720 760 139OO 750 760 780 - Softening p.
Ts ( ⁰ C) 800 860 III 840 905 III 950 Ts ² / £ x 10 " ⁷
( ⁰ C ³ ) 9400 I43OO - I3OOO I9OOO - 11200 Rating d.
Kri echfesti gk IV I. IV II I. Breakthrough
spg. (kV) - - - - 161

1093U / 1953

Attempt no. 5 65 59 - 60 - 61 62 63 - 64 - Chemical
To compose. 35 2 SiO ₂ - 5 30th 30th 55 50 50, Al ₂ O ₃ 15th 20th 3 25th 25th 20th 17th 15th Pe ₂ O ₃ 5 6th 4th - - - - - B ₂ O ₃ - - 20th 1 - - 3 - Na ₂ O 30th 1 6th - - 5 5 5 j ^K 2 ° 5 1 - - - 5 5 10 MgO 5 - 1 10 10 5 5 4th CaO - - 1 25th 25th - 5 5 BaO 0.4 0.4 - 9 10 5 5 5 Further 0.2 0.2 - - - Li ₂ O 51 A ₂ O 5 L i ₂ 0 6 Sb ₂ O ₅ . 0.4 0.4 0.4 0.4 0.4 0.4 As ₂ O ₅ 70
I. 72 0.2 0.2 0.2 0.2 0.2 0.2 Physical
Characteristics: _ Expansion
coefficient £ (° c)
Transitional
( ⁰ C) - - 60
670 65
690 72 71
680 74
680 78
670 Yield point
( ⁹ C) III III 750 810 - 760 770 760 Softening sp
Ts ( ⁰ C)
O 7
φ- '/ Υ ν 1 C \ ~~'
IS / ¹ K / X IU
( ⁰ C ³ ) - - 860
I23OO 950
I39OO - 890
11200 880
IO3OO 850
9300 Rating d.
Creep strength II I. III I. I. III Punch through
spg. (kV) 159

1 098 U / 1 953

Attempt no 65 ϊ · 30th - 66 §1 - 0.4 _ 68 60 III 70 71 • 48 ». 72 Chemical
Assemble 10 0.2 15th 700 SiO ₂ 5 30th 30th 30th - 60 55 790 40 Al ₂ O ₅ 15th 10 9 55 5 - 14- 15- 910 - Fe _o 0 _z - 5 5 670 5 - - - I74OO 5 B ₂ O ₃ - 20th 21st 750 25th - 0.5 1 I. 20th Na ₂ O 10 - - 890 - 15th - - 5 K ₂ O - - - 14400 - 5 0.5 1 5 MgO nO2O
b0 10 - - III - 5 15th 10 - CaO 0.4 - - - 0.4- 5 10 - BaO
rZ
further {ρ 0.2 ZnO 25 ZnO 25
PbO 10 PbO 10 ZnO 25
PbO 10 0.2 5 7th
ZnO 1 ZnO 20
PbO 5 Sb ₂ O ₅ 0.4 0.4 0.4- 0.4 0.4 As ₂ O ₅ 54 0.2 0.2 4-0 0.2 0.2 0.2
! ■■ III JIIUII l ^ ¹ * Physical
properties 680 Expansion
koeff, - ( ⁰ C) 780 56 55 43 61 * Transitional
( ⁰ C) 910 670 660 - 700 670 Yield point I57OO 760 74-0 - 790 720 Softening p.
Ts ² / ^ x 10 ~ ⁷ I. 900 870 910 870 (° c ^J ) 14-500 13600 I93OO 12400 Rating d.
Creep resistance, I. IV I. II Breakthrough
spg. (JcV) «.

1098U / 1963

Attempt no 21st Currently 21st i 4th - - Chemical
Composition 8th - - SiO ₂ 39 30th 56 - 68
580 85
640 Al ₂ O ₃ - - 2 - 630 .700 Fe ₂ O ₃ 5 5 SnO 20 ZnO 20 ~. _n ^ _n
^D b0 5PbO 10 ^rüU -> ^u 690
7OOO 770
6900 B ₂ O ₃ 21st 25th 0.4 IV V Na ₂ O VJI 5 0.2 - - E ₂ O 5 VJl 65
600 MgO - - 650 CaO - - 700
7500 BaO
fs
another 13 III Sb ₂ O ₅ - As ₂ O ₅ Physical
properties
ExpansionSy
coefficient <X (° C ~ ^x )
Transitional Yield point
( ⁰ C) Softening p.
Ts ² / ocx 10 ~ ⁷
( ⁰ C ³ ) Rating d.
Creep strength Punch through
spg. (kV)

109814/1963

In the diagram of FIG. 4, the value Ts is plotted on the abscissa and the evaluation number for the creep strength is plotted on the ordinate. The experiments in Table 3 and other experiments not specified are entered in this diagram. The numbers in the diagram indicate the test number in Table 3. According to FIG. 4 should, in order to achieve the evaluation numerals I or II, be an insulator made of tempered glass made of a glass composition whose softening point between 800 and 1200 ⁰ C, and its relationship Ts ² / oC between 8000 χ 10 ⁷ and 30 000 χ 10 ⁷ ( ⁰ C ³ ) lies. The dashed lines in FIG. 4 show that, at a softening point in the range between 800 and 1200 ° C., the value of the creep strength rises higher when the fourth of Ts / o6 is increased over 8000 χ 10. Conversely, however, it falls if the value Ts ² / <£, 30,000 χ ΙΟ ⁷ exceeds.

Example 2

In addition to the starting materials of Example 1, titanium oxide, zirconia and beryllium oxide were used. the

Proportions "■) of all these materials were chosen so that the mixed oxide compositions of the experiments in Table 4 showed. Tempered glass insulators made from these mixtures were subjected to the same tests as in Example 1 and carried out in the same way. The results are shown in Table 4 similar to Table 3. The experiments numbered from 1 to 75 correspond to Table 4 those of the experiments also numbered from 1 to 75 in Table 3. It should be noted that the Creep strength of each group of the corresponding numbers in the tests of Table 4 is higher than that of the Table 3.

Fig. 5 is a graph showing the results of Example 2 in the same manner as Fig. 4 shows the results of Example Fig. 5 shows that in Ex the measured value of their creep strength passed as in Example 1.

1098U / 1953

Table 4

Test results

Attempt no. 1 2 3 4th 5 6th 7th 8th ¹ 50 Chemical
Coll. 14th SiO ₂ 73 55 59 54 55 57 55 5 Al ₂ O ₅ 11 18th 19th 20th 10 17th 20th 1 B ₂ O ₅ - 11 - 5 5 3 4th 7th Na ₂ O 4th - 1 1 - 1 1 5 κ ₂ ο 5 1 4th 2 3 5 2 8th MgO 3 2 3 4th 7-5 - 2 - CaO 3 5 9 7th 6th 14th 14th BaO - 6th 5 2 3 2 -

1 0981 kl 19 53

Port setting «

Attempt no. 1 2 3 4th 5 6th 7th 8th Co ₂ O ₃ 0.2 - - - - - - - NOK - 0.2 - - - - - -! Further
'Cr ₂ O ₃ 1 2 0.2 5
0.2 10 - Cu ₂ O - - - - 0.5 - - ZrO ₂ - - - - - 0.2 2 10 Sb ₂ O ₅ 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 As ₂ O ₅ 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Physical
Characteristics: Expansion
koeff ./ < ^o C} 63 40 53 51 53 61 54 64 Transitional
( ⁰ C) 650 670 750 700 700 690 680 660 Yield point
( ⁸ C) 760 < 770 760 < 760 760 770 760 760 Softening ρ .
Ts ( ⁰ C)
m 2 . f , _Λ -7
Ts // - χ 10 980 975 95O < 940 920 914 920 890 (° C ³ ) 15200 23800 17000 1 7300 16000 I37OO I57OO 12400 Rating d.

Creep strength

Durchschiagspg. (kV)

II

II

1098U / 19S3

Attempt no. BeO 9 10 11 12th 13th 14th 15th 16. I. Chemical more ^ To compose ZrO ₂ - SiO ₀ . Sb ₂ O ₅ 51 47 44 51 41 50 57 53 • Al ₂ O ₃ As ₂ O ₅ 17th 17th 21st 10 23 17th 15th 10 Fe ₂ O ₃ Physical - - - - - - - - I ^B 2 ° 3 Characteristics: 20th 12th 12th 14th 14th 13th 3 14; Na ₂ O Extension Sy - - 1 - ■ 1 - 2 K ₂ O coefficient £ (C7) 1 1 1 1 1 1 - 2 MgO Transitional 6th 11 4th 6th 8th 2 5 1 CaO (C) 5 10 8th 8th 13th 16 4th 3 j BaO Yield point - - 4th - - - 6th 5 ( ⁰ C) 0.2 2 VJl 10 0.1 0.1 - LfN Softening p. - - - - 0.1 - VJi LA Ts ( ⁰ C) - - - - - 0.1 5 - Ts ² / oC χ 10 " ⁷ 0.4 0.4 0.4 0.4 0.4 0.4 0.4 0.4 (° C ^J ) 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 I.
Rating d. Creep strength I punch spg. (kV) 38 50 52 55 52 54 56 60 640 680 670 670 670 650 680 650 760 770 770 770 750 750 790 770 870 865 860 870 845 841 890 850 I99OO 15000 14200 13800 I37OO 13100 14100 12000 * I. I. I. I. II II I. - 160 - 158 - - 158

1098U / 1953

Attempt no. BeO 17th 18th 19th Ill 20th 21st Ill - 22nd - 40 Ill - 24 - Chemical
Composition ■ more / pjn / 1 "9S 41 'SiO ₂ ZrO ₂ 50 30th 29 80 81 40 - 40; Al ₂ O ₃ Sb ₂ O ₅ 5 15th 15th 1 - 40 9 j ^Fe 2 ° 3 As ₂ O ₅ - - - - - - 5 - B ₂ O ₃ I physical
Characteristics:
Expansion *
coefficient - ^ cT ¹ ) 9 10 10 9 9 10 4.5 10 Na ₂ O Transitional
(C) 3 3 · 3 5 5 5 - 4th K ₂ O Yield point 1 5 5 4.5 4.5 4.5 - 5 MgO Softening p.
Ts ² AiCx 10 " ⁷
( ⁰ C ³ ) - 9 10 - - - - - CaO Rating d.
Creep strength 3 20th 20th - - - 40 BaO Punch through
spg. (kV) 5 7th 6th - - - 0.5 - 25th - - - 4.5 - - 1 - 1 1 - - 0.5 0.4 - - - - 0.5 - - 0.2 - 0.4 0.4 0.4 0.4 0.4 0.4 71 0.41 0.2 0.2 0.2 0.2 0.2 0.2 0.2 70 65 65 50 48 70 70 690 7OO 720 730 740 - 740 780 780 - 780 790 800 800 920
12100 930
I33OO - 940
I75OO - 950
12800 940
12500; I. I. I. I. I. -

OR / GINAL INSPECTED

Attempt no. BeO Sb ₂ O 25th 26th 27 28 29 30th mm 31 12th Chemical
Composition TiO ₀
another 2 As ₂ O ₅ IkI.'i ... SiO ₂ ZrO ₂ Physical
Characteristics: 40 40 40 40 40 45 30th 30th Al ₂ O ₃ ExpansionSy
coefficient ^ C ^ " ¹ ) - 1 - 10 10 10 10 10 Fe ₂ O ₃ Transitional
( ⁰ C) - - - 2 1 1 2 1 B ₂ O ₃ Yield point
(M 9 7th 7th 15th 15th 15th 40 41 Na ₂ O Softening p.
Ts ( ⁶ C) 4th Ui 5 - - - - - K ₂ O Ts ² / * Cx 10 "" ⁷ 5 5 5 5 5 5 3 3 MgO ( ⁰ C ³ ) - 40 41 - - - - .- CaO Rating d.
Creep strength 41 - - 6th 6th 6th 8th 8th BaO Breakthrough
spg. (kV) - - - 20th 21st 15th 5 5 - - - - - - - - - 2 2 - - - 1 1 - - - 2 2 2 1 1 0.4 0.4 0.4 0.4 0o4 0.4 0.4 0.4 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 - 68 45 46 70 71 65 56 55 720 . ₁₁ 680 _{r l} 680 670 670 - 790 - 750 - 750 770 760 860 860 870 840 835 - 16500 - IO5OO - 11600 I25OO 12600 III I. III I. III I. I. III //in 165 09 8 1 4 r 1 «J "fr-sJ * - noin

ZrO ₂ 1 33 52 50 - 29 - 12th 74 2047661 39 6th 3 40 Attempt no. -. BeO
Further
Li ₂ O 680 10 35 36 635 38 _ Chemical
Composition TiO ₂ 30th 760 14th 60 700 60 2 60 ; SiO ₂ Sb ₂ O ₅ 10 815 6th 50 60 7th 760 60 7th IA 7th Al ₀ O-,
^ 3 Physical
Characteristics: 15th I27OO 3 10 7th 6th 7800 7th 3 13th B ₂ O ₅ Extension S ₁ -
koef £ .G ( ^ö C) LfN I. 5 12th 7th 3 III 7th - 3 Na ₂ O Transitional
( ⁹ C) 3 _ 5 8th 3 11 3 3
11 - ■ ^K 2 ° Yield point;
( ⁰ C) 5 5 3 10 2 - - 2 i MgO Softening p. 8th 1 5 2 LfN 2 _- 5 CaO Ts ² // χ 10 " ⁷
( ⁰ C ³ ) LfN - 5 LfN 3 5 3 . BaO Rating d.
Creep strength 1 1 5 3 - 3 66 - Breakthrough
spg. (kV) - - 1 - 3 - 660 VJl VM 1 - 3 - 3
10 750 - 64 1 - - · - 830 670 - - 10400 740 III 58 800 67 70 65 680 10,000 650 640 660 760 III 720 720 750 860 780 785 840 I27OO 11500 8800 10800 I. I. III I. mm 158

1 O 9 8 1 A / 1 9 ß 3

Attempt no 41 42 43 44 44 46 47 48 Chemical
Composition 3 SiO ₂ 60 50 45 44 5 50 50 50 Al ₂ O ₃ 7th 5 5 5 - 13th 11 11 Fe ₂ O ₃
B ₂ O ₃ 5 5 5 5 5 10 7th 6th Na ₂ O 3 - - - 2 - - - K ₂ O - 5 5 5 3 3 3 3 MgO 2 2 2 2 - 7th 7th 7th CaO 8th 3 3 3 10 10 10 BaO 3 - - - - - -

1098U / 1963

Continuation,

Attempt no. 13th 42 43 44 45 46 47 48 Li ₂ O - - - - - - - - ZnO _ 25th 30th 31 35 - - - PbO 3 - - - 5 10 11 ^continue BeO - ■ - - - - - - - TiO ₂ VJl VJI 5 5 - - - ZrO ₂ 0.4 _ _ - 2 2 2 Sb ₂ O ₅ 0.2 0.4 0.4 0.4 0.4 0.4 0.4 0.4 As ₂ O ₅ 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Physical
properties 65 Expansion y 640 56 58 59 60 55 60 62 Transitional
( ⁵ C) 750 680 660 650 640 £ 60 640 640 Yield point 840 780 760 750 740 760 750 750 Softening p.
Ts ( ⁰ C) IO9OO 850 850 830 820 850 840 830 Ts ² Mx io ~ ⁷
( ⁰ C ³ ) . III 12800 I23OO 11600 11200 13000 11700 11100 Rating d.
Creep strength - I. I. III III I. I. III ¹ Punch through
spq. (kV) - - - - 158 - -

1098U / 1963

PbO 42 50 - 32 - 53 5 £ t L 7RR 1 8th Attempt no. ZrO ₂ 51 £ 2 55 40 Chemical
Put together zg, ^welter % o ₂ 50 55 55 46 5 SiO ₂ BeO 13th 10 55 55 0.5 - 30th 14th Al ₂ O ₅ Sb ₂ O ₅ - 5 10 10 - - 40 3 Fe ₀ O, As ₂ O ₅ 4th 7th 6th 8th 15th 15th - - B ₂ O ₅ Physical
properties - 2 7th 7th 3 3 15th - Na ₂ O ExpansionSy
coefficient X (° C) 1 3 2 2 3 3 1 30th K ₂ O Transitional
( ⁰ C) 7th 8th 3 3 16 16 - - MgO Yield point 10 5 8th 8th 0.5 - - - CaO Softening p.
Ts ( ⁰ C) - 5 4th 2 7th 7th 14th - BaO Ts ² / ocg io " ⁷ 15th - 5 5 - - - - Rating d.
Creep strength 0.15 0.2 - - - - - Punch through
spg. (kV) - - O0I5 - - 0.2 0.4 - - - 0.1 - 26th - 0.2 0.4 0 "4 - - 0.4 0.4 - 0.2 0.2 0.4 0.4 0.2 0.2 0.4 66 0.2 0.2 0.2 _ 68 52 43 43 - 610 670 52 54 650 80 720 760 670 660 760 - 7OO - 800 860 760 750 905 780 Ill 9400 14300 850 840 I9OOO - 950 - I. "■ III I. 139OO I3OOO I. Ill 11200 - - III III - I. - - 161

1098U / .1983

TiO ₂ 5 - £ 8 - - 33 - 60 61 - 2047661 63 64 Attempt no. ZrO ₂ 24 - - 59 - 62 Chemical
Composition more _π _
BeO - - 54 - 30th 30th - 50 50 SiO ₂ LiO ₂ 15th Ill 2 III 40 25th 5 Ill 17th 15th Al ₂ O ₅ Sb ₂ O ^ 5 5 3 - - 21st - - Fe ₂ O ₃ ^As 2 ° 5 - 20th 4th 1 - - 3 -. B ₂ O ₃ Physical
Characteristics: 30th 6th 10 - - - 5 5 Na ₂ O Expansion y
coefficient-U ^o c " ^x ) - 5 - - 4th 5 10 K ₂ O Transitional
( ⁰ C) 5 1 - 10 10 5 4th 3 MrO Yield point 11 1 1 25th 4th 6th 5 5 CaO Softening p.
Ta ( ⁰ C) _n
Ts ^Z / Xx ΙΟ ""'
(° C *> • - 1 9 10 - 5 5 BaO Rating d.
Creep strength - 11 - - 10 5 0.2 0.2 Punch through
spg. (kV) - 5 - - 10 0.2 - - 0.4 - 6th 0.2 21st - - - 0.2 - 20th - - - 5 6th 0.4 - 0.4 0.4 5 0.4 0.4 65 0.2 0.4 0.2 0.2 0.4 0.2 0.2 0.2 0.2 70 65 70 75 78 4-3 690 70 680 670 680 810 680 770 760 760 950
13900 770 880
10300 850
9300 870
17700 I. 890
11300 ' I. III I. • mm I. _. _ 159

1098U / 1963

Attempt no. BaO 65 66 30th 68 62 • 60 - 70 71 72 Chemical
Composition TiO ₂ 8.5 14th III SiO ₂ further ZrO ₂ 30th 30th 5 30th - 60 55 40 Al ₀ O _x
d 3 ZnO 9.5 9.5 21st 4.5 - 14th 15th - έ 3 PbO 5 5 - 5 - - - 5 B ₂ O ₃ Sb ₂ O ₅ 15th 20th - 25th - 0.5 1 20th Na ₂ O As ₅ O ₅ - - - - 15th - - 5 K ₂ O Physical
Characteristics: - - - - 5 0.5 1 5 MgO Expansion «·
koeff. ^ rc " ¹ ) 10 - - - 5 Λ5 10 - CaO ■ Transitional period
( ⁰ C) - ■ - - 1 5 10 - BaO Yield point - - - - - 5 7th - Softening p.
Ts ( ⁰ C)
Ts ² AjCx 10 ~ ⁷
( ⁰ C ³ ) - - 0.5 - - 0.2 0.2 - Rating d.
Creep strength 0.5 0.5 25th - - - - 1 Breakthrough
spg. TkV) - - 10 0.5 - - - - 20th 25th 0.4 25th 0.4 - 1 20th 10 10 0.2 10 0.2 - - 5 0.4 0.4 0.4 0.4 0.4 0.4 0.2 0.2 55 0.2 40 0.2 0.2 0.2 670 53 55 750 56 43 48 60 | 680 670 890
14400 660 700 700 670 780 760 III 740 790 790 720 910
I57OO 900
14800 870
13600 910
I93OO 910
I74OO 870
12600 I. I. IV I. I. II _ mm

1098U / 1963

Attempt no. TiO ₂ 21st 21st 21st Chemical ZnO Composition Further " -.
ZrOp SiO ₂ PbO 38 30th 56 Al ₀ O, Sb ₂ O ₅ - - 2 Fe ₂ O ₃ As ₂ O ₁ - VJl VJl - B ₂ O ₃ Physical 21st 25th - Na ₂ O properties 5 5 4th K ₂ O Expansion _T
coefficient: C ( ^o C ~ ^x ) 5 VJI 8th M _S 0 Transitional - - - CaO Yield point
(C) - - - BaO - - - Softening p.
Ts ( ⁰ C) 1 0.1 _ Ts ² A ₃ Cx 10 "" ⁷ 20th 20th - ( ⁰ C ³ ) - - 0.1 Rating d VJl 10 30th Creep strength 0.4 0.4 0.4 Breakthrough . 0.2 0.2 0.2 spg. (kV) 66 68 85 600 580 640 650 630 7OO 700 690 770 7400 7OOO 6900 III III IV - - -

Ίο 9TuTTaTT

If in the above description and the following claims proportions from zero to a certain Value are given, it should be understood that the lower limit is to be selected so that the desired effect is achieved. The lower limit can then be taken from the above examples.

1098 U / 1 953

Claims (2)

Claims 1. Solidified glass insulator, characterized by a glass composition, which meets the following three conditions: (A) the proportions of the constituents of the glass mass lie in the following areas: Wt%
..30 - 0-40 CaO 0-40 MgO 0-40 BaO Austria - 20th ■ -. + CaO. 1-69 ₅ + CaO + MgO + BaO 5-69 0-5 K ₂ O 0-10 Na ₂ O + K ₂ O 0-10 Li ₂ O 0-10 B ₂ O ₅ .... '. . 0-40 ZnO O-3O PbO 0-10 Fe ₀ O, 0-5 B ₀ O, + ZnO + PbO + Fe ₀ O, 0-60 2 3 d $ Na ₀ O + K ₀ O + Li ₀ O + B ₀ O, + ZnO + PbO + Fe ₀ O, dddd 2 d 0 1-60; 1098U / 1963 (B) the softening point is between 800 and 1200 ⁰ C; and (C) the value of the ratio L soft point ( ⁰ C) J / mean linear expansion coefficient,] [at temperatures between 100 and 300 ⁰ C (° C ~) J lies between 8000 χ 10 ⁷ and 30,000 χ 10 ⁷ ( ⁰ C ³ ). 2. Insulator according to claim 1, characterized in that the glass composition additionally includes the following components contains the following proportions: ZrO ₂
Ti0 ₂
BeO ZrO ₂ + TiO ₂ + BeO Weight -% 0 - 10 0 - 20th 0 - 25th 0.2 - 40. 1098U / 1983 Blank page