Plumbing is any system that conveys fluids for a wide range of applications. Plumbing uses pipes, plumbing fixtures and other apparatuses to convey fluids. Heating and cooling, waste removal, potable water delivery are among the most common uses for plumbing, but it is not limited to these applications; the word derives from the Latin for lead, plumbum, as the first effective pipes used in the Roman era were lead pipes. In the developed world, plumbing infrastructure is critical to public sanitation. Boilermakers and pipefitters are not plumbers, although they work with piping as part of their trade, but their work can include some plumbing. Plumbing originated during ancient civilizations such as the Greek, Persian and Chinese cities as they developed public baths and needed to provide potable water and wastewater removal, for larger numbers of people. Standardized earthen plumbing pipes with broad flanges making use of asphalt for preventing leakages appeared in the urban settlements of the Indus Valley Civilization by 2700 BC.
The Romans used lead pipe inscriptions to prevent water theft. The word "plumber" dates from the Roman Empire; the Latin for lead is plumbum. Roman roofs used lead in conduits and drain pipes and some were covered with lead. Lead was used for piping and for making baths. Plumbing reached its early apex in ancient Rome, which saw the introduction of expansive systems of aqueducts, tile wastewater removal, widespread use of lead pipes. With the Fall of Rome both water supply and sanitation stagnated—or regressed—for well over 1,000 years. Improvement was slow, with little effective progress made until the growth of modern densely populated cities in the 1800s. During this period, public health authorities began pressing for better waste disposal systems to be installed, to prevent or control epidemics of disease. Earlier, the waste disposal system had consisted of collecting waste and dumping it on the ground or into a river; the development of separate, underground water and sewage systems eliminated open sewage ditches and cesspools.
Most large cities today pipe solid wastes to sewage treatment plants in order to separate and purify the water, before emptying into streams or other bodies of water. For potable water use, galvanized iron piping was commonplace in the United States from the late 1800s until around 1960. After that period, copper piping took over, first soft copper with flared fittings with rigid copper tubing utilizing soldered fittings; the use of lead for potable water declined after World War II because of increased awareness of the dangers of lead poisoning. At this time, copper piping was introduced as a safer alternative to lead pipes; the major categories of plumbing systems or subsystems are: potable cold and hot tap water supply plumbing drainage venting sewage systems and septic systems with or without hot water heat recycling and graywater recovery and treatment systems Rainwater and subsurface water drainage fuel gas piping hydronics, i.e. heating and cooling systems utilizing water to transport thermal energy, as in district heating systems, like for example the New York City steam system.
A water pipe is a pipe or tube made of plastic or metal, that carries pressurized and treated fresh water to a building, as well as inside the building. For many centuries, lead was the favoured material for water pipes, because its malleability made it practical to work into the desired shape; this was a source of lead-related health problems in the years before the health hazards of ingesting lead were understood. Lead water pipes were still used in the early 20th century, remain in many households. In addition, lead-tin alloy solder was used to join copper pipes, but modern practice uses tin-antimony alloy solder instead, in order to eliminate lead hazards. Despite the Romans' common use of lead pipes, their aqueducts poisoned people. Unlike other parts of the world where lead pipes cause poisoning, the Roman water had so much calcium in it that a layer of plaque prevented the water contacting the lead itself. What causes confusion is the large amount of evidence of widespread lead poisoning amongst those who would have had easy access to piped water.
This was an unfortunate result of lead being used in cookware and as an additive to processed food and drink, for example as a preservative in wine. Roman lead pipe inscriptions provided information on the owner to prevent water theft. Wooden pipes were elsewhere during the 16th and 17th centuries; the pipes were hollowed-out logs, which were tapered at the end with a small hole in which the water would pass through. The multiple pipes were sealed together with hot animal fat, they were used in Philadelphia and Montreal in the 1800s, built-up wooden tubes were used in the USA during the 20th century. These pipes, used in place of corrugated iron or reinforced concrete pipes, were made of sections cut from short lengths of wood. Locking of adjacent rings with hardwood dowel pins produced a flexible structure. About 100,000 feet of these wooden pipes were installed during WW2 in drainage culverts, storm sewers and conduits, under highways and at army camps, naval stations and ordnance plants. Cast iron and ductile iron pipe was long a lower-cost alternative to copper, before the advent of durable plastic materials but special non-conductive fittings must be used where transitions are to be made to other metallic pipes, except for terminal fittin
Paper is a thin material produced by pressing together moist fibres of cellulose pulp derived from wood, rags or grasses, drying them into flexible sheets. It is a versatile material with many uses, including writing, packaging, decorating, a number of industrial and construction processes. Papers are essential in non-legal documentation; the pulp papermaking process is said to have been developed in China during the early 2nd century CE as early as the year 105 CE, by the Han court eunuch Cai Lun, although the earliest archaeological fragments of paper derive from the 2nd century BCE in China. The modern pulp and paper industry is global, with China leading its production and the United States right behind it; the oldest known archaeological fragments of the immediate precursor to modern paper date to the 2nd century BCE in China. The pulp paper-making process is ascribed to a 2nd-century CE Han court eunuch. In the 13th century, the knowledge and uses of paper spread from China through the Middle East to medieval Europe, where the first water powered paper mills were built.
Because paper was introduced to the West through the city of Baghdad, it was first called bagdatikos. In the 19th century, industrialization reduced the cost of manufacturing paper. In 1844, the Canadian inventor Charles Fenerty and the German F. G. Keller independently developed processes for pulping wood fibres. Before the industrialisation of paper production the most common fibre source was recycled fibres from used textiles, called rags; the rags were from hemp and cotton. A process for removing printing inks from recycled paper was invented by German jurist Justus Claproth in 1774. Today this method is called deinking, it was not until the introduction of wood pulp in 1843 that paper production was not dependent on recycled materials from ragpickers. The word "paper" is etymologically derived from Latin papyrus, which comes from the Greek πάπυρος, the word for the Cyperus papyrus plant. Papyrus is a thick, paper-like material produced from the pith of the Cyperus papyrus plant, used in ancient Egypt and other Mediterranean cultures for writing before the introduction of paper into the Middle East and Europe.
Although the word paper is etymologically derived from papyrus, the two are produced differently and the development of the first is distinct from the development of the second. Papyrus is a lamination of natural plant fibres, while paper is manufactured from fibres whose properties have been changed by maceration. To make pulp from wood, a chemical pulping process separates lignin from cellulose fibres; this is accomplished by dissolving lignin in a cooking liquor, so that it may be washed from the cellulose. Paper made from chemical pulps are known as wood-free papers–not to be confused with tree-free paper; the pulp can be bleached to produce white paper, but this consumes 5% of the fibres. There are three main chemical pulping processes: the sulfite process dates back to the 1840s and it was the dominant method extent before the second world war; the kraft process, invented in the 1870s and first used in the 1890s, is now the most practiced strategy, one of its advantages is the chemical reaction with lignin, that produces heat, which can be used to run a generator.
Most pulping operations using the kraft process are net contributors to the electricity grid or use the electricity to run an adjacent paper mill. Another advantage is that this process reuses all inorganic chemical reagents. Soda pulping is another specialty process used to pulp straws and hardwoods with high silicate content. There are two major mechanical pulps: groundwood pulp. In the TMP process, wood is chipped and fed into steam heated refiners, where the chips are squeezed and converted to fibres between two steel discs. In the groundwood process, debarked logs are fed into grinders where they are pressed against rotating stones to be made into fibres. Mechanical pulping does not remove the lignin, so the yield is high, >95%, however it causes the paper thus produced to turn yellow and become brittle over time. Mechanical pulps have rather short fibres. Although large amounts of electrical energy are required to produce mechanical pulp, it costs less than the chemical kind. Paper recycling processes can use mechanically produced pulp.
Most recycled paper contains a proportion of virgin fibre for the sake of quality. There are three main classifications of recycled fibre:. Mill broke or internal mill waste – This incorporates any substandard or grade-change paper made within the paper mill itself, which goes back into the manufacturing system to be re-pulped back into paper; such out-of-specification paper is not sold and is therefore not classified as genuine reclaimed recycled fibre, however most paper mills have been reusing their own waste fibre for many years, long before recycling became popular. Preconsumer waste – This is offcut and processing waste, such as guillotine trims and envelope blank waste.
The Wonderful Wizard of Oz
The Wonderful Wizard of Oz is an American children's novel written by author L. Frank Baum and illustrated by W. W. Denslow published by the George M. Hill Company in Chicago on May 17, 1900, it has since seen several reprints, most under the title The Wizard of Oz, the title of the popular 1902 Broadway musical adaptation as well as the iconic 1939 musical film adaptation. The story chronicles the adventures of a young farm girl named Dorothy in the magical Land of Oz, after she and her pet dog Toto, are swept away from their Kansas home by a cyclone; the book is one of the best-known stories in American literature and has been translated. The Library of Congress has declared it "America's greatest and best-loved homegrown fairytale." Its groundbreaking success and the success of the Broadway musical adapted from the novel led Baum to write thirteen additional Oz books that serve as official sequels to the first story. Baum dedicated the book "to my good friend & comrade, My Wife," Maud Gage Baum.
In January 1901, George M. Hill Company completed printing the first edition, a total of 10,000 copies, which sold out, it sold three million copies by the time it entered the public domain in 1956. The book was published by George M. Hill Company; the first edition had a printing of 10,000 copies and was sold in advance of the publication date of September 1, 1900. On May 17, 1900, the first copy came off the press; the public saw it for the first time at a book fair at the Palmer House in Chicago, July 5–20. Its copyright was registered on August 1. By October 1900, it had sold out and the second edition of 15,000 copies was nearly depleted. In a letter to his brother, Baum wrote that the book's publisher, George M. Hill, predicted a sale of about 250,000 copies. In spite of this favorable conjecture, Hill did not predict that the book would be phenomenally successful, he agreed to publish the book only when the manager of the Chicago Grand Opera House, Fred R. Hamlin, committed to making it into a musical stage play to publicize the novel.
The play The Wizard of Oz debuted on June 16, 1902. It was revised to suit adult preferences and was crafted as a "musical extravaganza," with the costumes modeled after Denslow's drawings. Hill's publishing company became bankrupt in 1901, so Baum and Denslow agreed to have the Indianapolis-based Bobbs-Merrill Company resume publishing the novel. Baum's son, Harry Neal, told the Chicago Tribune in 1944 that Baum told his children "whimsical stories before they became material for his books." Harry called his father the "swellest man I knew," a man, able to give a decent reason as to why black birds cooked in a pie could afterwards get out and sing. By 1938, more than one million copies of the book had been printed. Less than two decades in 1956, the sales of it had grown to three million copies in print. Dorothy is a young girl who lives with her Aunt Em, Uncle Henry, dog, Toto, on a farm on the Kansas prairie. One day and Toto are caught up in a cyclone that deposits them and the farmhouse into Munchkin Country in the magical Land of Oz.
The falling house has killed the Wicked Witch of the evil ruler of the Munchkins. The Good Witch of the North arrives with three grateful Munchkins and gives Dorothy the magical silver shoes that once belonged to the Wicked Witch; the Good Witch tells Dorothy that the only way she can return home is to follow the yellow brick road to the Emerald City and ask the great and powerful Wizard of Oz to help her. As Dorothy embarks on her journey, the Good Witch of the North kisses her on the forehead, giving her magical protection from harm. On her way down the yellow brick road, Dorothy attends a banquet held by a Munchkin named Boq; the next day, she frees a Scarecrow from the pole on which he is hanging, applies oil from a can to the rusted joints of a Tin Woodman, meets a Cowardly Lion. The Scarecrow wants a brain, the Tin Woodman wants a heart, the Cowardly Lion wants courage, so Dorothy encourages them to journey with her and Toto to the Emerald City to ask for help from the Wizard. After several adventures, the travelers arrive at the Emerald City and meet the Guardian of the Gates, who asks them to wear green tinted spectacles to keep their eyes from being blinded by the city's brilliance.
Each one is called to see the Wizard. He appears to Dorothy as a giant head, to the Scarecrow as a lovely lady, to the Tin Woodman as a terrible beast, to the Cowardly Lion as a ball of fire, he agrees to help them all. The Guardian warns them that no one has managed to defeat the witch; the Wicked Witch of the West sees the travelers approaching with her one telescopic eye. She sends a pack of wolves to tear them to pieces, she sends wild crows to peck their eyes out. She summons a swarm of black bees to sting them, but they are killed while trying to sting the Tin Woodman while the Scarecrow's straw hides the others, she sends a dozen of her Winkie slaves to attack them, but the Cowardly Lion stands firm to repel them. She uses the power of her Golden Cap to send the Winged Monkeys to capture Dorothy and the Cowardly Lion, unstuff the Scarecrow, dent the Tin Woodman. Dorothy is forced to become the witch's personal slave, while the witch schemes to steal her silver shoes; the witch tricks Dorothy out of one of her silver shoes.
Angered, she is shocked to see her melt away. The Winkies rejoice at being freed from her tyranny and help restuff the Scarec
Litterfall, plant litter, leaf litter, tree litter, soil litter, or duff, is dead plant material that have fallen to the ground. This detritus or dead organic material and its constituent nutrients are added to the top layer of soil known as the litter layer or O horizon. Litter has occupied the attention of ecologists at length for the reasons that it is an instrumental factor in ecosystem dynamics, it is indicative of ecological productivity, may be useful in predicting regional nutrient cycling and soil fertility. Litterfall is characterized as fresh and recognizable plant debris; this can be anything from leaves, needles, bark, seeds/nuts, logs, or reproductive organs. Items larger than 2 cm diameter are referred to as coarse litter, while anything smaller is referred to as fine litter or litter; the type of litterfall is most directly affected by ecosystem type. For example, leaf tissues account for about 70 percent of litterfall in forests, but woody litter tends to increase with forest age.
In grasslands, there is little aboveground perennial tissue so the annual litterfall is low and quite nearly equal to the net primary production. In soil science, soil litter is classified in three layers, which form on the surface of the O Horizon; these are the L, F, H layers: The litter layer is quite variable in its thickness, decomposition rate and nutrient content and is affected in part by seasonality, plant species, soil fertility and latitude. The most extreme variability of litterfall is seen as a function of seasonality. In tropical environments, the largest amount of debris falls in the latter part of dry seasons and early during wet season; as a result of this variability due to seasons, the decomposition rate for any given area will be variable. Latitude has a strong effect on litterfall rates and thickness. Litterfall declines with increasing latitude. In tropical rainforests, there is a thin litter layer due to the rapid decomposition, while in boreal forests, the rate of decomposition is slower and leads to the accumulation of a thick litter layer known as a mor.
Net primary production works inversely to this trend, suggesting that the accumulation of organic matter is a result of decomposition rate. Surface detritus facilitates the infiltration of rainwater into lower soil layers. Soil litter protects soil aggregates from raindrop impact, preventing the release of clay and silt particles from plugging soil pores. Releasing clay and silt particles reduces the capacity for soil to absorb water and increases cross surface flow, accelerating soil erosion. In addition soil litter reduces wind erosion by preventing soil from losing moisture and providing cover preventing soil transportation. Organic matter accumulation helps protect soils from wildfire damage. Soil litter can be removed depending on intensity and severity of wildfires and season. Regions with high frequency wildfires have reduced vegetation density and reduced soil litter accumulation. Climate influences the depth of plant litter. Humid tropical and sub-tropical climates have reduced organic matter layers and horizons due to year round decomposition and high vegetation density and growth.
In temperate and cold climates, litter tends to accuculate and decompose slower due to a shorter growing season. Net primary production and litterfall are intimately connected. In every terrestrial ecosystem, the largest fraction of all net primary production is lost to herbivores and litterfall. Due to their interconnectedness, global patterns of litterfall are similar to global patterns of net primary productivity. Litter provides habitat for a variety of organisms. Certain plants are specially adapted for thriving in the litter layers. For example, bluebell shoots puncture the layer to emerge in spring; some plants with rhizomes, such as common wood sorrel do well in this habitat. Many organisms that live on the forest floor are decomposers, such as fungi. Organisms whose diet consists of plant detritus, such as earthworms, are termed detritivores; the community of decomposers in the litter layer includes bacteria, nematodes, tardigrades, cryptostigmata, insect larvae, oribatid mites and millipedes.
Their consumption of the litterfall results in the breakdown of simple carbon compounds into carbon dioxide and water, releases inorganic ions into the soil where the surrounding plants can reabsorb the nutrients that were shed as litterfall. In this way, litterfall becomes an important part of the nutrient cycle that sustains forest environments; as litter decomposes, nutrients are released into the environment. The portion of the litter, not decomposable is known as humus. Litter aids in soil moisture retention by cooling the ground surface and holding moisture in decaying organic matter; the flora and fauna working to decompose soil litter aid in soil respiration. A litter layer of decomposing biomass provides a continuous energy source for macro- and micro-organisms. Numerous reptiles, amphibians and some mammals rely on litter for shelter and forage. Amphibians such as salamanders and caecilians inhabit the damp microclimate underneath fallen leaves for part or all of their life cycle. Thi
A funnel is the smokestack or chimney on a ship used to expel boiler steam and smoke or engine exhaust. They are commonly referred to as stacks; the primary purpose of a ship's funnel is to lift the exhaust gases clear of the deck, in order not to foul the ship's structure or decks, to avoid impairing the ability of the crew to carry out their duties. In steam ships the funnels served to help induce a convection draught through the boilers. Since the introduction of steam-power to ships in the 19th century, the funnel has been a distinctive feature of the silhouette of a vessel, used for recognition purposes; the required funnel cross-sectional area is determined by the volume of exhaust gases produced by the propulsion plant. This area is too great for a single funnel. Early steam vessels needed multiple funnels, but as efficiency increased new machinery needed fewer funnels. Merchant shipping companies were quick to recognise the publicity value of distinctive funnels, both in terms of shape, number of funnels, the colours they were painted.
In an era when ship hulls were uniformly painted black and superstructures were white the funnel was one of the few parts of the ship that a company could use to differentiate its ships from those of its competitors. Each company would have their own "house colours", which were used in publicity material as well as for recognition, making funnel colours an early form of trademark; some companies became so associated with their funnel colours that their nickname became a de facto company name. For example, the shipping line registered as'Alfred Holt & Company' was more known as the Blue Funnel Line; the Southampton, Isle of Wight and South of England Royal Mail Steam Packet Company has traded under the name Red Funnel for most of its 150+ year history. Other colours such as the red with black stripes of the Cunard Line and the all buff colour of P&O remain icons of their respective lines and have remained in use for over a century through many changes of corporate ownership. Sometimes the shape of the funnel is used as distinguishing feature rather than just the colour.
Cunard fitted ships of its Saxonia class with streamlined round tops to the funnels. Intended as an aerodynamic aid to keep exhaust clear of the deck the modification had little practical effect but was retained because it made the four ships of the class recognisable and gave Cunard a suitable modern image. There was a trend for'designer funnels' on liners in the 1960s as fashion and aerodynamic advances combined to offer designers more options that the traditional cylindrical smokestack; the Italian Line fitted the liners Michelangelo and Raffaello with funnels topped by flat discs supported on exposed diagonal bracing while P&O's Oriana and Canberra had tall, thin funnels with aerofoil cross sections. In the late 19th and the first half of the 20th century the number of funnels became associated with speed and reliability. For this reason a number of the great liners carried additional false funnels that they did not need. Examples included the White Star Line's RMS Titanic, Hamburg America Line's SS Imperator, the French Line's SS Normandie.
In most cases there was only a single false funnel placed as the aftermost of the funnels. The false funnels did have more uses than aiding aesthetics however - a stoker who survived the sinking of the Titanic escaped the boiler room by ascending the false funnel, the aft funnel of Normandie housed the passengers' dog kennels, Disney Cruise Line's Disney Magic's forward funnel plays host to a teens-only club. For example, the RMS Queen Elizabeth 2 was built with distinctive wind-scoops at the base of her funnel; when fitted with new diesel engines in 1987, which had a different exhaust requirement to the old boilers, the new funnel was built to the same silhouette as the old one, in order to retain this distinctive recognition feature. A key part of the deception practiced by ships carrying out commerce raiding during both the First World War and Second World War was to disguise their ship's outline, this included using false funnels or by changing the height or diameter of the actual funnel.
A mack is a combined stack and mast. Although they can reduce top-weight, they have not gained universal popularity due to the problem of exhaust gases corroding electrical aerials and equipment
A liquid is a nearly incompressible fluid that conforms to the shape of its container but retains a constant volume independent of pressure. As such, it is one of the four fundamental states of matter, is the only state with a definite volume but no fixed shape. A liquid is made up of tiny vibrating particles of matter, such as atoms, held together by intermolecular bonds. Water is, by far, the most common liquid on Earth. Like a gas, a liquid is able to take the shape of a container. Most liquids resist compression. Unlike a gas, a liquid does not disperse to fill every space of a container, maintains a constant density. A distinctive property of the liquid state is surface tension; the density of a liquid is close to that of a solid, much higher than in a gas. Therefore and solid are both termed condensed matter. On the other hand, as liquids and gases share the ability to flow, they are both called fluids. Although liquid water is abundant on Earth, this state of matter is the least common in the known universe, because liquids require a narrow temperature/pressure range to exist.
Most known matter in the universe is in gaseous form as interstellar clouds or in plasma from within stars. Liquid is one of the four primary states of matter, with the others being solid and plasma. A liquid is a fluid. Unlike a solid, the molecules in a liquid have a much greater freedom to move; the forces that bind the molecules together in a solid are only temporary in a liquid, allowing a liquid to flow while a solid remains rigid. A liquid, like a gas, displays the properties of a fluid. A liquid can flow, assume the shape of a container, and, if placed in a sealed container, will distribute applied pressure evenly to every surface in the container. If liquid is placed in a bag, it can be squeezed into any shape. Unlike a gas, a liquid is nearly incompressible, meaning that it occupies nearly a constant volume over a wide range of pressures; these properties make a liquid suitable for applications such as hydraulics. Liquid particles are bound but not rigidly, they are able to move around one another resulting in a limited degree of particle mobility.
As the temperature increases, the increased vibrations of the molecules causes distances between the molecules to increase. When a liquid reaches its boiling point, the cohesive forces that bind the molecules together break, the liquid changes to its gaseous state. If the temperature is decreased, the distances between the molecules become smaller; when the liquid reaches its freezing point the molecules will lock into a specific order, called crystallizing, the bonds between them become more rigid, changing the liquid into its solid state. Only two elements are liquid at standard conditions for temperature and pressure: mercury and bromine. Four more elements have melting points above room temperature: francium, caesium and rubidium. Metal alloys that are liquid at room temperature include NaK, a sodium-potassium metal alloy, galinstan, a fusible alloy liquid, some amalgams. Pure substances that are liquid under normal conditions include water and many other organic solvents. Liquid water is of vital importance in biology.
Inorganic liquids include water, inorganic nonaqueous solvents and many acids. Important everyday liquids include aqueous solutions like household bleach, other mixtures of different substances such as mineral oil and gasoline, emulsions like vinaigrette or mayonnaise, suspensions like blood, colloids like paint and milk. Many gases can be liquefied by cooling, producing liquids such as liquid oxygen, liquid nitrogen, liquid hydrogen and liquid helium. Not all gases can be liquified at atmospheric pressure, however. Carbon dioxide, for example, can only be liquified at pressures above 5.1 atm. Some materials cannot be classified within the classical three states of matter. Examples include liquid crystals, used in LCD displays, biological membranes. Liquids have a variety of uses, as lubricants and coolants. In hydraulic systems, liquid is used to transmit power. In tribology, liquids are studied for their properties as lubricants. Lubricants such as oil are chosen for viscosity and flow characteristics that are suitable throughout the operating temperature range of the component.
Oils are used in engines, gear boxes and hydraulic systems for their good lubrication properties. Many liquids are used as solvents, to dissolve other solids. Solutions are found in a wide variety of applications, including paints and adhesives. Naphtha and acetone are used in industry to clean oil and tar from parts and machinery. Body fluids are water based solutions. Surfactants are found in soaps and detergents. Solvents like alcohol are used as antimicrobials, they are found in cosmetics and liquid dye lasers. They are used in processes such as the extraction of vegetable oil. Liquids tend to have better thermal conductivity than gases, the ability to flow makes a liquid suitable for removing excess heat from mechanical components; the heat can be removed by channeling the liquid through a heat exchanger, such as a radiator, or the heat can be removed with the liquid durin
A separatory funnel known as a separation funnel, separating funnel, or colloquially sep funnel, is a piece of laboratory glassware used in liquid-liquid extractions to separate the components of a mixture into two immiscible solvent phases of different densities. One of the phases will be aqueous, the other a lipophilic organic solvent such as ether, MTBE, chloroform, or ethyl acetate. All of these solvents form a clear delineation between the two liquids; the more dense liquid the aqueous phase unless the organic phase is halogenated and can be drained out through a valve away from the less dense liquid, which remains in the separatory funnel. A separating funnel takes the shape of a cone with a hemispherical end, it has a stopper at the stopcock, at the bottom. Separating funnels used in laboratories are made from borosilicate glass and their stopcocks are made from glass or PTFE. Typical sizes are between 30 mL and 3 L. In industrial chemistry they can be much larger and for much larger volumes centrifuges are used.
The sloping sides are designed to facilitate the identification of the layers. The stopcock-controlled outlet is designed to drain the liquid out of the funnel. On top of the funnel there is a standard taper joint which fits with a ground glass or Teflon stopper. To use a separatory funnel, the two phases and the mixture to be separated in solution are added through the top with the stopcock at the bottom closed; the funnel is closed and shaken by inverting the funnel multiple times. The funnel is inverted and the tap opened to release excess vapor pressure; the separating funnel is set aside to allow for the complete separation of the phases. The top and the bottom tap are opened and the lower phase is released by gravitation; the top must be opened while releasing the lower phase to allow pressure equalization between the inside of the funnel and the atmosphere. When the bottom layer has been removed, the stopcock is closed and the upper layer is poured out through the top into another container.
The separatory funnel runs on the concept of "like dissolves like", with different solutes being preferentially soluble in certain solvents. While a separatory funnel is being shaken, the two solvents mix and share a large surface area, which allows each solute to migrate to the solvent in which it is more soluble; the solvents do not form a unified solution together. When the funnel is allowed to sit after being shaken, the liquids form distinct physical layers, with the less dense liquid floating and more dense sinking. A mixture of solutes is thus separated into two physically separate solutions, each enriched in different solutes; the bottom layer is drained out the top layer can be retained in the separatory funnel for further extractions with additional batches of solvent or drained out into a separate vessel for other uses. If it is desired to retain the bottom layer in the separatory funnel for further extractions, both layers are taken out separately, the former bottom layer is returned to the separatory funnel.
Each independent solution can be extracted again with additional batches of solvent, used for other physical or chemical processes. If the goal was to separate a soluble material from mixture, the solution containing that desired product can sometimes be evaporated to leave behind the purified solute. For this reason, it is a practical benefit to use volatile solvents for extracting the desired material from the mixture. One of the drawbacks of using a separatory funnel is emulsions can form and can take a long time to separate once formed, they are formed while liquids are being mixed in the separatory funnel. This can occur. If an emulsion is formed, one technique used to separate the liquids is to swirl the solution in the separatory funnel. If the emulsion is not separated by this process, a small amount of saturated saline solution is added. Research is being done on alternative, more efficient techniques utilizing stir bars to decrease or eliminate the chance of emulsification, thus decreasing the amount of waiting time.
The largest risk when using a separatory funnel is that of pressure build-up. Pressure accumulates during mixing if a gas evolving physical change occurs; this problem can be handled by opening the stopper at the top of the funnel while mixing. This should be done with the top of the funnel pointed away from the body. Decantation is a process of pouring off the top layer of liquid from a bottom layer of liquid or solid Decanter centrifuge Dropping funnels are similar in shape and design, may be used as separatory funnels, they have standard taper ground glass joints at the stem. Partition coefficient is a measure of the distribution of an analyte between the two phases in a separation