002.399.Idrija

Idrija Mercury Heritage Management Center, Bazoviška 2, SI-5280 Idrija

Public

Republic of Slovenia

/

Daily life

A three-phase mercury rectifier essentially consists of power (i.e. energetic part of the converter) and control (regulative) part. A closed glass bowl (“electronic tube”) is pear-shaped and has 8 semiconductor diodes on the bottom and the middle part. These are flat and regularly shaped with the exception of the smallest diode, which is curved and empty. Four diodes are equally large, three diodes in the central part are larger and higher, but one is significantly smaller. There are two cathodes, filled with mercury, completely at the bottom. There is no mercury in the others, but they are equipped with anodes. All the anodes, except the smallest one, have fused conductors (cathodes) at the end. The bowl is blackened, which is the result of mercury evaporation. On the upper third, the bowl is equipped with a metal clamp.

Length 57 cm, width 48 cm, height 65 cm.

Glass, mercury, steel, rope.

First half of the 20th century

Manufacturer information is not known.

Mercury rectifiers were used from 1902 to 1960 for converting AC to DC. They were helpful for large flows (thousands of amps) and high voltages (around 1000 volts). They were used to drive the electric tramways, galvanisation, electrolytic acquisition of elements etc. The rectifier contained several kilograms of mercury. The bowl with very low vapour pressure contains mercury, which starts to evaporate when connected to the electrical voltage, or is releasing electrons, which leads to ionisation or to valve ignition. Ionised gas molecules of Hg are involved in the transition of electric current inside the container. In the higher, colder parts of the bowl the mercury cools down, and then slides towards the middle part in the liquid form.

The three-phase mercury rectifier is being preserved, secured and presented as important mining heritage of Idrija with exceptional universal values. It is a part of the CUDHg Smelting Collection. Visitors can view it within the permanent museum display “From Ore to Mercury Drops” in the Hg Smelting Plant, which represents the characteristics and the versatile use of mercury in science, technology, medicine, culture and every day life. Within the exhibition the object is placed in the density segment and it represents the usefulness of mercury for technical devices.

Private use.

Hg Smelting Plant (From Ore to Mercury Drops), Arkova 50, SI-5280 Idrija

The three-phase mercury rectifier is well preserved. Additional interventions are not necessary. Security of the premise is taken care off.

good

Regular seasonal maintenance.

- CUDHg Inventory Book.

Mestni muzej Idrija

Miha Kosmač

17. 3. 2018

Never