Silica gel Breather is cylindrical type container which is fitted to the conservator tank through a pipe line which is totally filled with silica gel crystals used for absorbing any moisture present in the air during breathing action of transformer due to expansion and contraction of transformer oil in the transformer. The size of Breather depends on the volume of transformer main tank as well as quantity of transformer oil in the transformer. A oil pot is connected under the breather. The details of silica gel Breather is shown in figure.
Fig. 1 ( Before moisture absorbed )
When the Silica gel breather is first installed, the crystals have a blue tint, and after a period of operation, the colour of the tinted crystals gradually changes to pink , this is an indication that the silica gel is becoming saturated and losing its absorbent properties. When there is a preponderance of pink crystals the silica gel should be changed or reactivated.
Fig. 2 ( after moisture absorbed )
Silicagel may be reactivated by heating in a thin pan at a temperature of 1500C to 2000C for two to three hours when the crystals should have regained their original blue tint. Before filling the container with silica gel, clean and dry all parts of the breather. Verify that the oil level in the oil cup is correct or not –correct. Finally ensure that the breather is not choked and is free for passage of air.
More details go to:-
 Multiple Choice Question (MCQ) of Electronics page-17:241. Which of the following statement is true? a) The saturation voltage VCF of silicon transistor is more than germanium transistor. b) The saturation voltage VCE for germanium transistor is more than silicon transistor. c) The saturation voltage VCE for silicon transistor is same as that for germanium. d) The saturation voltage VCE for silicon transistor is lower than germanium transistor. |
Multiple Choice Question (MCQ) of Electronics page-16:226. Which of the following statement is correct? a) Inner electrons are always present in the semiconductor. b) Bound electrons are always present in the semiconductor. c) Free electrons are always present in the semiconductor. d) Inner and bound electrons are always present in the semiconductor. |
Multiple Choice Question (MCQ) of Electronics page-15:211. The materials whose electrical conductivity is usually less than 1 × 106 mho/m are a) Semiconductors b) Conductors c) Insulators d) Alloys |
Multiple Choice Question (MCQ) of Electronics page-14:196. In which of the following device the base resistors are not added in the package but added externally? a) UJT b) CUJT c) PUT d) None of the above |
Multiple Choice Question (MCQ) of Electronics page-13:181. The conduction in JEFT is always by the a) Majority carriers b) Minority carriers c) Holes d) Electrons e) Holes and electrons simultaneously |