US2976440A

US2976440A - Gas filled rectifier

Info

Publication number: US2976440A
Application number: US795717A
Authority: US
Inventors: Lamm Uno
Original assignee: ASEA AB
Current assignee: ABB Norden Holding AB
Priority date: 1958-03-03
Filing date: 1959-02-26
Publication date: 1961-03-21
Anticipated expiration: 1978-03-21

Description

Filed Feb. 26, 1959 INVENTOR. Unoilamm Patented Mar. 2 1,:1961

United States Patent Ofice GAS FILLED RECTIFIER Uno Lamm, Vasteras, Sweden, assignor to Allmanna Sveuska Elektriska Aktiebolaget, Vasteras, Sweden, a corporation of Sweden Filed Feb. 26, 1959, Ser. No. 795,717

Claims priority, application Sweden Mar. 3, 1958 8 Claims. (Cl. 313-19) The present invention refers to a gas filled rectifier with two or more anodes. Hitherto such gas filled rectifiers were made with the anodes arranged at the top of a vertical, substantially cylindrical tank. In most cases the anodes were then arranged symmetrically in relation to the mercury cathode in the bottom of the tank. When the number of anodes was comparatively low such rectifiers did not give any construction difliculties. If, on the other hand, the number of anodes is great, which often is the case in high voltage rectifiers where the anodes are also often arranged in great insulating domes, the diameter of the tank will be considerable, and this involves several drawbacks. One of these is that the rectifiers then demand a great deal of room. This is unfavourable especially if the plant consists of several rectifiers as this involves high costs for premises. Another drawback is the constructive difiiculties as the stresses, especially on the end of the rectifier tank, will be very great. Since pressure in the rectifier tank is very low, the ends could be pressed inwards by the outer pressure.

In order to reduce the dimensions of the gas filled rectifier and in order to overcome theproblems of structural strength, according to the invention, it is proposed to make the rectifiers in the form of a horizontally placed, substantially cylindrical tank'forming a common condensing chanrber for the anode units which are placed upon the upper part of the tank. By this construction of the rectifier tank its structural strength will be as favourable as possible. As the anode units are arranged on the shell of the tank, the diameter of the tank will be independent of the number of anodes and only the length of the tank will be dependent on said number of anodes, and as the anodes are arranged in domes outside the tank, the diameter, and therefore the volume, of this will be reduced to a minimum. The length of the tank can be limited further if the anode units are placed in two or more parallel rows in the longitudinal direction of the tank. According to the invention, a rectifier is obtained the dimensions of which, vertically and latitudinally, are substantially independent of the number of anodes. It is therefore possible to make effective use of the room where the rectifiers are placed.

In a rectifier according to the invention the placing of the cathode causes no difliculties. One or more mercury cathodes could be arranged opposite to the anodes on the shell of the tank, that is in the lower part of the shell of the tank. In order to lead condensed mercury back into the cathodes, sheets could be suitably arranged inside the tank.

An essential advantage of a rectifier according to the invention is that the cooling problem can be solved simply. Because of the small diameter of the tank it is usually not necessary to use liquid cooling medium, but fans could be arranged for air cooling of the rectifier tank and anode units. The cooling air could be led in such a way that separate air streams pass the rectifier tank and the anode units. This result could be obtained when the rectifier tank is surrounded by one casing and the anode units are arranged in another casing. 7

The invention is to be described with reference to the followin drawings which show two embodiments of the invention. Figures 1 and 2 show two dilferent elevational views of one of the embodiments and Figures 3 and 4, two different elevational views of the other.

In Figures 1 and 2, 1 is a horizontally placed, cylindrical tank which, on its lower part of the shell, has a cathode 2 and on the top ofthe shell, four anodes arranged in the domes 3 to 6. The rectifier tank 1 is surrounded by a casing 7 in which a fan s driven by a motor 9 is-arranged. In the bottom of the casing an inlet 10 is arranged for the cathodes 1 1.

From the figures it vwill be seen that the diameter of the rectifier tank may be comparatively small in spite of the fact that four anodes are arrangedon it. Therefore it is possible to make effective use of the space available 'for the rectifiers which form the plant. In this embodiment of the invention, no special cooling for the anodes has been considered necessary.

In the embodiment of the invention according to Figures 3 and 4, eight parallel working anodes arranged in domes 12 to 19 are arranged in two rows on the rectifier tank 20. This is provided with two

mercury cathodes

21, 22. In the same way as in Figure 1 the rectifier tank is surrounded by a casing 23. The anodes are surrounded by another casing 24 which is provided with a partition wall 25 in which a fan 26 driven by a motor 27 is arranged. Thereby it is possible to circulate cooling air in the casing, which cooling air passes first the anode units in one row and then the units in the other row, as the partition wall is not extended entirely to the opposite end of the casing 24. In the casing 24, openings 28, 29 may be arranged, which eventually could be provided with flaps by means of which the supply of fresh external air, and the disposal terials, in which case the resistors of the voltage dividers could be attached direct on the sides. In Figure 4, such an arrangement is indicated for the anode unit 14. In the figure are shown three terminals for

auxiliary electrodes

32, 33, 34, which are connected to the

resistors

35, 36 which are attached at the insulating side 30. The figure also shows a capacitor pile 37 which is connected to the voltage divider which consists of the

resistors

35 and 36. In the figure are also shown

capacitor piles

38, 39 and 40 for the

anodes

12, 16 and 18.

Instead of arranging the cooling of the anode units in the way shown in the Figures 3 and 4, other constructions may also be used. For example, it may be advantageous to lead the cooling air in the longitudinal direction of the anode units.

If gas-filled rectifiers according to the invention are used in a plant, they could be arranged either in a common room or they could be arranged outdoors, in which case I claim:

1. A gas-filled rectifier comprising the combination of at least two separate anode units and at least one mercury cathode and a metal tank forming a common condensing chamber for said anode units, said tank having a substantially cylindrical shell, the axis of said shell being horizontal, said anode units being situated on the upper part of said shell and being arranged in at least one row extending longitudinally of the tank, said mercury cathode being arranged on the lower part of said shell of the tank.

2. A gas-filled rectifier as claimed in claim 1, provided with sheets inside said tank, said sheets being adapted to lead condensed mercury back to said mercury cathode.

3. A gas-filled rectifier as claimed in claim 1, provided with a casing surrounding said tank, and means for passing a cooling medium between said tank and said casing.

4. A gas-filled rectifier as claimed in claim 1, provided with a casing surrounding the anode units, and means for passing a cooling medium between said casing and said units.

5. A gas-filled rectifier as claimed in claim 4, said casing having sides of electric insulating material.

6. A gas-filled rectifier as claimed in claim 5, said anode units being provided with auxiliary electrodes; voltage dividers for said auxiliary electrodes; said voltage dividers being arranged on said insulating side; said auxiliary electrodes being connected to taps on said voltage dividers.

7. A gas-filled rectifier as claimed in claim 5, provided with a roof supported by said insulating sides, the anodes of the rectifier being connected to said roof.

8. A gas-filled rectifier as claimed in claim 7, a conductor for the rectifier being connected directly to said roof; said conductor connecting the anodes and the DC. network.

References Cited in the file of this patent UNITED STATES PATENTS 1,587,932 Bagley June 8, 1926 1,751,423 Robinson Mar. 18, 1930 1,952,306 Bird Mar. 27, 1934