I teamed up with Marshall and qx for a quick trip into Belgium, for another look into the Premetro since neither of them had been before.
Naturally we skimped on accomodation but this little rooftop and the weather accomodated us beautifully.
The following day, totally by surprise, we chanced upon a Mecury Arc Fucking Rectifier. I've been waiting to see one of these suckers in the flesh for years, back since I heard there was one in Tennyson Powerstation. I never saw the ones in teeps but then years later sitting on top of a silo in Montreal I heard a story of a local one employed for the railway whick resparked the flame. Again years passed without finding one but finally, when I'd almost given up hope one just popped up out of nowhere.
Great but what the fuck is so special about a stumpy glass octopus full of liquid mercury and what does it do? Enter wikipedia:
A mercury arc valve (mercury vapor rectifier) is a type of electrical rectifier which converts alternating current into direct current. Rectifiers of this type were used in electric motor power supplies for industry, in electric railways, streetcars and electric locomotives. They were also utilized in static inverter stations and as rectifiers for high-voltage direct current power transmission.
The mercury arc rectifier was invented by Peter Cooper Hewitt in 1902 and further developed throughout the 1920s and 1930s by researchers in both Europe and North America. Before the advent of solid-state devices, mercury arc rectifiers were one of the more efficient rectifiers. Mercury arc rectifiers or "converters" were used for charging storage batteries and in arc lighting systems where they were found to be more efficient than rotary converters.
One type of mercury vapor electric rectifier consists of an evacuated glass bulb, with a pool of liquid mercury sitting in the bottom as the cathode.[2] Over it curves the glass bulb, which condenses mercury evaporated in the course of operation of the device. The glass envelope has one or more arms with graphite rods as anodes. Their number depends on the application. If direct current is to be produced from single-phase alternating current, then two anodes are used, each connected to the outer ends of a centre-tapped transformer secondary winding. During operation, the arc transfers to the anodes at the highest positive potential (with respect to the cathode). Design of the arms and envelope is intended to prevent an arc from forming between the anodes; such a condition is called "backfire" and is a critical factor in the design of mercury arc rectifiers.
Glass envelope rectifiers can produce hundreds of kilowatts of direct-current power in a single unit. A 6-phase rectifier rated 150 amperes has a glass envelope approximately 600 mm (24 inches) high by 300 mm (12 inches) outside diameter. These rectifiers will contain several pounds of liquid mercury. The large size of the envelope is required due to the low thermal conductivity of glass. Mercury vapor in the upper part of the envelope must give up heat through the glass envelope to condense and return to the cathode pool.
If that doesn't have you all worked up into a sweat, here's what they look like working:
source: [ame]http://en.wikipedia.org/wiki/Mercury_arc_valve[/ame]
Moist.
Naturally we skimped on accomodation but this little rooftop and the weather accomodated us beautifully.
The following day, totally by surprise, we chanced upon a Mecury Arc Fucking Rectifier. I've been waiting to see one of these suckers in the flesh for years, back since I heard there was one in Tennyson Powerstation. I never saw the ones in teeps but then years later sitting on top of a silo in Montreal I heard a story of a local one employed for the railway whick resparked the flame. Again years passed without finding one but finally, when I'd almost given up hope one just popped up out of nowhere.
Great but what the fuck is so special about a stumpy glass octopus full of liquid mercury and what does it do? Enter wikipedia:
A mercury arc valve (mercury vapor rectifier) is a type of electrical rectifier which converts alternating current into direct current. Rectifiers of this type were used in electric motor power supplies for industry, in electric railways, streetcars and electric locomotives. They were also utilized in static inverter stations and as rectifiers for high-voltage direct current power transmission.
The mercury arc rectifier was invented by Peter Cooper Hewitt in 1902 and further developed throughout the 1920s and 1930s by researchers in both Europe and North America. Before the advent of solid-state devices, mercury arc rectifiers were one of the more efficient rectifiers. Mercury arc rectifiers or "converters" were used for charging storage batteries and in arc lighting systems where they were found to be more efficient than rotary converters.
One type of mercury vapor electric rectifier consists of an evacuated glass bulb, with a pool of liquid mercury sitting in the bottom as the cathode.[2] Over it curves the glass bulb, which condenses mercury evaporated in the course of operation of the device. The glass envelope has one or more arms with graphite rods as anodes. Their number depends on the application. If direct current is to be produced from single-phase alternating current, then two anodes are used, each connected to the outer ends of a centre-tapped transformer secondary winding. During operation, the arc transfers to the anodes at the highest positive potential (with respect to the cathode). Design of the arms and envelope is intended to prevent an arc from forming between the anodes; such a condition is called "backfire" and is a critical factor in the design of mercury arc rectifiers.
Glass envelope rectifiers can produce hundreds of kilowatts of direct-current power in a single unit. A 6-phase rectifier rated 150 amperes has a glass envelope approximately 600 mm (24 inches) high by 300 mm (12 inches) outside diameter. These rectifiers will contain several pounds of liquid mercury. The large size of the envelope is required due to the low thermal conductivity of glass. Mercury vapor in the upper part of the envelope must give up heat through the glass envelope to condense and return to the cathode pool.
If that doesn't have you all worked up into a sweat, here's what they look like working:
source: [ame]http://en.wikipedia.org/wiki/Mercury_arc_valve[/ame]
Moist.
