Gas holder


A gas holder or gasholder, also known as a gasometer, is a large container in which natural gas or town gas is stored near atmospheric pressure at ambient temperatures. The volume of the container follows the quantity of stored gas, with pressure coming from the weight of a movable cap. Typical volumes for large gas holders are about, with structures.
Gas holders now tend to be used for balancing purposes to ensure that gas pipes can be operated within a safe range of pressures, rather than for actually storing gas for later use.

Etymology

devised the first gas holder, which he called a gazomètre, to assist his work in pneumatic chemistry. It enabled him to weigh the gas in a pneumatic trough with the precision he required. He published his Traité Élémentaire de Chimie in 1789. James Watt Junior collaborated with Thomas Beddoes in constructing the pneumatic apparatus, a short-lived piece of medical equipment that incorporated a gazomètre. Watt then adapted the gazomètre for coal gas storage.
The anglicisation "gasometer" was adopted by William Murdoch, the inventor of gas lighting, in 1782, as the name for his gas holders. Murdoch's associates objected that his "gasometer" was not a meter but a container, but the name was retained and came into general use. Gas holders were marked as gasometers on the large-scale maps issued by the British Ordnance Survey and the term came to be used to label gas works, even though there may be several gas holders at any one gas works. However, the term "gasometer" is still discouraged for use in technical circles, where "gas holder" is preferred.
The spelling "gas holder" is used by the BBC, among other institutions, but the variant "gasholder" is more commonly used.

History

Before the mid-20th century coal gas was produced in retorts by heating coal in the absence of air, the process being known as coal gasification. Coal gas was first used for municipal lighting, the gas being passed through wooden or metal pipes from the retort to the lantern. The first public piped gas supply was to thirteen gas lamps installed along the length of Pall Mall, London, in 1807. The credit for this installation goes to the German inventor and entrepreneur Frederick Albert Winsor. Digging up streets to lay pipes required easements, and this delayed both further installation of street lighting and the installation of gas for domestic illumination, heating and cooking.
Many people experimented with coal distillation to produce a flammable gas, including Jean Tardin, Clayton, Jean-Pierre Minckelers, Leuven and Pickel. William Murdoch was successful. He joined Boulton and Watt at the Soho manufactory in Birmingham in 1777, and in 1792 he built a retort to heat coal to produce the gas that illuminated his home and office in Redruth. His system lacked a storage method until James Watt Junior adapted a Lavoisier gazomètre for this purpose. A gasometer was incorporated into the first small gasworks built for the Soho manufactory in 1798.
William Murdoch and his pupil Samuel Clegg went on to install retorts in individual factories and other workplaces. The earliest was in 1805, at Lee & Phillips, Salford Twist Mill, where eight gas holders were installed. This was shortly followed by one in Sowerby Bridge, constructed by Clegg for Henry Lodge.
The first independent commercial gas works were built by the Gas Light and Coke Company in Great Peter Street, Westminster, in 1812, with wooden pipes laid to gas lights on Westminster Bridge on New Year's Eve in 1813. Public gas lights were seen as a means to reduce crime and until the 1840s they were regulated by police authorities.
Because of safety concerns expressed by the Royal Society, the size of gas holders was limited to and they were enclosed in gasometer houses. In fact any small leak from an enclosed gas holder created a potentially explosive build-up of air and gas within the enclosing house, presenting a far greater danger than the original leak did; putting houses around gas holders was discontinued in the UK. In the United States, however, where gas needed to be protected from much more extreme weather, gasometer houses continued to be built and were architecturally decorative.
The telescopic gas holder was first invented in 1824. The cup and dip seal was patented by Hutchinson in 1833, and the first working example was built in Leeds. Gas holders were then built all around the UK in great numbers starting in the 1850s. The first were the two-lift column-supported type; later ones had four lifts and were frame-guided, and they could be retrofitted with an additional flying lift. The large gas holders at Kings Cross, London, were built in the 1860s.
William Gadd of Gadd & Mason in Manchester invented the spirally guided gas holder in 1890. Instead of external columns or guide frames, his design operated with spiral rails. The first commercial design was built in Northwich, Cheshire, in the same year. By the end of the 19th century most towns in Britain had their own gas works and gas holders.
The years between the two world wars were marked by improvements in storage, especially the waterless gas holder, and in distribution, with the advent of steel pipes to convey gas at up to as feeder mains to the traditional cast iron pipes. Municipal gas works became superfluous in the later 20th century, but gas holders and production plants were still in use in steel works in 2016.

Function

A gas holder provides storage for purified, metered gas. It acts as a buffer, removing the need for continuous gas production. The weight of the gas holder lift controlled the pressure of the gas in the mains and provided back pressure for the gas-making plant.
They are the only storage method that keeps gas at district pressure.

Types

There are two basic types of gas holder: the water-sealed and the rigid waterless.
The water-sealed gas holder consists of a tank of water that rises and falls to take the gas. A watered gas holder consisted of two parts: a deep tank of water used to provide a seal, and a closed vessel that rises above the water as the gas volume increased.
Rigid waterless gas holders were a very early design that neither expanded or contracted. There are modern versions of the waterless gas holder, e.g. oil-sealed, grease-sealed and "dry seal" types. They consist of a fixed cylinder capped by a moving piston.

Water-sealed gas holders

The earliest Boulton and Watt gas holders had a single lift. The tank was above ground and was lined with wood; the lift was guided by tripods and cables. Pulleys and weights were supplied to regulate the gas pressure. Brick tanks were introduced in 1818, when a gas holder could have a capacity of. The engineer John Malam devised a tank with a central rod-and-tube guide system.
Telescoping holders fall into two subcategories. The earlier of the telescoping variety were column-guided variations and were built starting in 1824. To guide the telescoping walls, or "lifts", they have an external frame, visible at a fixed height at all times. A refinement was the guide frame gas holder, where the heavy columns were replaced by a lighter and more extensive framework. Vertical girders were intersected by horizontal girders and cross-braced. This could be bolted onto an underground or above-ground tank. The Cutler patented guide frame dispensed with the horizontal girders, using diagonal triangulated framing instead. Cable-guided gas holders, invented by Pease in 1880, had a limited use, but were useful on unstable ground where the rigid systems could buckle and jam the lift.
Spiral-guided gas holders were built in the UK from 1890 until 1983. These have no frame, and each lift is guided by the one below, rotating as it goes up as dictated by helical runners.
Both telescoping types use the manometric property of water to provide a seal. The whole tank floats in a circular or annular water reservoir, held up by the roughly constant pressure of a varying volume of gas, the pressure determined by the weight of the structure, and the water providing the seal for the gas within the moving walls. Besides storing the gas, the tank's design serves to establish the pressure of the gas system. With telescoping tanks, the innermost tank has an approximately lip around the outside of the bottom edge, called a cup, which picks up water as it rises above the reservoir water level. This immediately engages a downward lip on the inner rim of the next outer lift, called a dip or grip, and as this grip sinks into the cup, it preserves the water seal as the inner tank continues to rise until the grip grounds on the cup, whereupon further injection of gas will start to raise that lift as well. Holders were built with as many as four lifts. An extra flying lift could be retrofitted into column or frame gas holders. This was an additional inner tank that extended above the standards, when the infrastructure would support the extra shear forces and weight. Though not exclusively, spiral guides were used.

Dry-seal-type gas holder

Dry-seal gas holders have a static cylindrical shell, within which a piston rises and falls. As it moves, a grease seal, tar/oil seal or a sealing membrane which is rolled out and in from the piston keeps the gas from escaping. The MAN type was introduced in 1915: it was polygonal and used a tar/oil seal. The Klonne dry seal gas holder was circular and used a grease seal. The dry-seal Wiggins gasholder was patented in 1952: it used a flexible curtain that was suspended from the piston. The largest low-pressure gas holder built was the Klonne gas holder built in 1938 in Gelsenkirchen. It was high and in diameter, which gave it a capacity of. There was a MAN type, built in 1934 in Chicago with a capacity of.

By location

Europe

In the past, holder stations would have an operator living on site controlling their movement. However, with the process control systems now used on these sites, such an operator is obsolete. The tallest gasometer in Europe is tall and is located in Oberhausen.
The pollution associated with gasworks and gas storage makes the land difficult to reclaim for other purposes, but some gas holders, such as the Vienna Gasometers, have been converted into other uses such as living space and a shopping mall and historical archives for the city. Many sites, however, were never used for the production of 'town gas', so the land contamination is relatively low.
A gasworks in South Lotts, Dublin, Ireland, was converted into apartments.
The gas holder in Amsterdam has hosted the Awakenings techno parties.