The terms acid egg and montejus (or monte-jus) are sometimes used interchangeably to refer to a device with no moving parts formerly used instead of a pump in order to transfer difficult liquids.Carl Schaschke (2014) ''Dictionary of Chemical Engineering'' (Oxford University Press) p 245D. H. Killeffer (1924) ''Industrial and Engineering Chemistry'' Vol. 16, No. 8 pp 785–8 “Tools of the Chemical Engineer” The principle is that a strong vessel containing the liquid is pressurized with gas or steam, forcing the liquid into a pipe (usually vertical upwards) thereby causing flow. When the liquid has been transferred, the

pressure Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country a ...

is released and more liquid is put in via

gravity In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the str ...

. It is thus cyclic in operation. The same principle has been used to lift water and called an ''air displacement pump'' or ''intermittent gas-lift pump'', and has been applied to pumping

oil An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) & lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturate ...

up from the formation.R. J. Forbes & D. R. O'Beirne (1957) ''The Technical Development of the Royal Dutch/Shell: 1890-1940'' p233 Its use has largely been superseded by modern pumps, but it is still used sometimes for special tasks.

Acid Egg

This was specifically devised to deal with the highly corrosive sulfuric acid, but was extended to other corrosive substances. It was traditionally made of

ceramic A ceramic is any of the various hard, brittle, heat-resistant and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcelai ...

(to be corrosion resistant) and spherical in shape (to withstand the pressure) thus giving its name.''Miriam-Webster Dictionary'' A cylindrical version (with hemispherical ends) was described by Swindin, being 3 feet in diameter and 6 feet long, holding 40 cubic feet of acid.Swindin, N., (1922) ''Pumps in Chemical Engineering'' (Benn, London) pp 48–9 In principle, the vessel is part filled with liquid, which is then expelled by pumping in compressed air. The liquid outlet is via a pipe from the top going down almost to the bottom of the vessel. When the acid egg is emptied, connections to the compressor and the delivery pipe are closed by valves, the air pressure is vented and the vessel refilled with acid. The cycle can then start again.

Montejus

A French invention used in

sugar production The sugar industry subsumes the production, processing and marketing of sugars (mostly sucrose and fructose). Globally, most sugar is extracted from sugar cane (~80% predominantly in the tropics) and sugar beet (~ 20%, mostly in temperate climate ...

to move the partially processed sugar liquid up a pipe to the next stage of purification. Hence the name “monte-jus” or “raise juice”. Unlike the acid egg, it traditionally consists of a vertical cylindrical vessel made of steel, with a pipe from the bottom turned upwards, and it is pressurized by steam.

Scientific American ''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many famous scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it. In print since 1845, it i ...

, April 24, 1869 pp 261–2, “Beet Root Sugar part V”

References

{{reflist Pumps Chemical equipment Chemical industry History of sugar