Vacuum cleaner
From Wikipedia, the free encyclopedia
A vacuum cleaner (in colloquial British English also hoover[1]) is a device that uses an air pump to create a partial vacuum to suck up dust and dirt, usually from floors. Most homes with carpeted floors in developed countries possess a vacuum cleaner for cleaning. The dirt is collected by a filtering system or a cyclone for later disposal.
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[edit] History of the Vacuum Cleaner
[edit] Ives W. McGaffney
The first manually-powered cleaner using vacuum principles was the "Whirlwind", invented in Chicago in 1868 by Ives W. McGaffney. The machine was lightweight and compact, but was difficult to operate because of the need to turn a hand crank at the same time as pushing it across the floor. McGaffney obtained a patent for his device on June 5, 1869, and enlisted the help of The American Carpet Cleaning Co. of Boston to market it to the public. It was sold for $25, a high price in those days. It is hard to determine how successful the Whirlwind was, as most of them were sold in Chicago and Boston, and it is likely that many were lost in the Great Chicago Fire of 1871. Only two are known to have survived, one of which can be found in the Hoover Historical Center.
McGaffney was but one of many 19th-century inventors in the United States and Europe who devised manual vacuum cleaners. The first patent for an electrically driven "carpet sweeper and dust gatherer" was granted to Corinne Dufour of Savannah, Georgia in December 1900.
[edit] H. Cecil Booth
The first powered cleaner employing a vacuum was patented and produced by Hubert Cecil Booth in 1901. He noticed a device used in trains that blew dust off the chairs, and thought it would be much more useful to have one that sucked dust. He tested the idea by laying a handkerchief on the seat of a dinner chair, putting his mouth to the handkerchief, and then trying to suck up as much dust as he could onto the handkerchief. Upon seeing the dust and dirt collected on the underside of the handkerchief he realized the idea could work. Booth created a large device, known as Puffing Billy, driven first by an oil engine, and later by an electric motor. It was drawn by horses and parked outside the building to be cleaned.
Booth started the British Vacuum Cleaner Company and refined his invention over the next several decades. Though his "Goblin" model lost out to competition from Hoover in the household vacuum market, his company successfully turned its focus to the industrial market, building ever-larger models for factories and warehouses. Booth's company lives on today as a unit of pneumatic tube system maker Quirepace Ltd.
[edit] Nilfisk
In 1910 P.A. Fisker patented a vacuum cleaner using a name based on the company’s telegram address - Nilfisk. It was the first electric vacuum cleaner in Europe. His design weighed just 17.5 kg and could be operated by a single person. The company Fisker and Nielsen was formed just a few years before. Today the Nilfisk vacuums are delivered by Nilfisk-Advance.
[edit] Walter Griffiths
In 1905 "Griffith's Improved Vacuum Apparatus for Removing Dust from Carpets" was another manually operated cleaner, patented by Walter Griffiths Manufacturer, Birmingham, England. It was portable, easy to store, and powered by "any one person (such as the ordinary domestic servant)", who would have the task of compressing a bellows-like contraption to suck up dust through a removable, flexible pipe, to which a variety of shaped nozzles could be attached. This was arguably the first domestic vacuum-cleaning device to resemble the modern vacuum cleaner.
[edit] David T. Kenney
Nine patents granted to the New Jersey inventor David T. Kenney between 1903 and 1913 established the foundation for the American vacuum cleaner industry. Membership in the Vacuum Cleaner Manufacturers' Association, formed in 1919, was limited to licensees under his patents.
[edit] James Murray Spangler
In 1907, James Murray Spangler, a janitor in Canton, Ohio invented an electric vacuum cleaner from a fan, a box, and a pillowcase. Crucially, in addition to suction, Spangler's design incorporated a rotating brush to loosen debris. Lacking the funds to produce his design himself, he sold the patent to W.H.Hoover.
[edit] Hoover
Spangler patented his rotating-brush design in 1908, and eventually sold the idea to his cousin's husband, W.H. Hoover. Hoover was looking for a new product to sell, as the leather goods produced by his 'Hoover Harness and Leather Goods' company were becoming obsolete, due to the invention of the automobile. In the United States, Hoover remains one of the leading manufacturers of household goods, including cleaners; and Hoover became very wealthy from the invention. Indeed, in Britain the colloquial term for a vacuum cleaner is a "hoover," and one "hoovers" one's carpets. Initially called 'The Electric Suction Sweeper Company', their first produced vacuum was the 1908 'Model O', which sold for $60.
Hoover is also notable for an unusual vacuum cleaner, the Hoover Constellation, which is a canister type but lacks wheels. Instead, the vacuum cleaner floats on its exhaust, operating as a hovercraft. Introduced in 1952, they are collectible, and are easily identified by the spherical shape of the canister. They tended to be loud, had poor cleaning power, and could not float over carpets. But they remain an interesting machine; restored, they work well in homes with lots of hardwood floors.
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In 1959 an updated Constellation with a stationary handle replaced the previous model and was made until 1980. These Constellations route all of the exhaust under the vacuum using a different airfoil. The updated design is quiet even by modern standards, particularly on carpet as it muffles the sound. These models float on carpet or bare floor - although on hard flooring, the exhaust air tends to scatter any fluff or debris around.
Hoover has now re-released an updated version of this later model Constellation in the US (model # S3341 in Pearl White and # S3345 in stainless steel). Changes include a HEPA filtration bag, a 12 amp motor, a suction turbine powered rotating brush floor head, and a redesigned version of the handle, which tended to break.
The 5.2 amp motor on older US units provides respectable suction but they all lack a motorized brush head. Therefore they generally work better on hard floors or short pile rugs. Old units take Hoover type J paper bags but the slightly smaller type S allergen filtration bags can be easily trimmed to fit the retaining notches on the old vacuums. Replacement motors are still available from Hoover US for some models.
Hoover made another hovering vacuum cleaner model called the Celebrity in the late sixties or early seventies. It has a flattened "flying saucer" shape. Hoover added wheels to it make it a conventional canister model after a brief run as a hovering vacuum. It uses type H bags.
[edit] Post-World War II
For many years after their introduction, vacuum cleaners remained a luxury item; but after World War II they became common among the middle classes. They tend to be more common in Western countries because, in some parts of the world, wall-to-wall carpeting is uncommon and homes have tile or hardwood floors, which are easily swept, wiped, or mopped.
Vacuum cleaners working on the cyclone principle became popular in the 1990s, although some companies (notably Filter Queen and Regina) have been making vacuum cleaners with cyclonic action since 1928. In 1959 Amway patented the first 'bagless' cyclonic vacuum, called the CMS 1000. Modern cyclonic cleaners were adapted from industrial cyclonic separators by British designer James Dyson in 1985. He launched his cyclone cleaner first in Japan in the 1980s at a cost of about US$1,800 and later the Dyson DC01 upright in the UK in 1995 for £200. It was expected that people would not buy a vacuum cleaner at twice the price of a normal cleaner, but it later became the most popular cleaner in the UK.
Cyclonic cleaners do not use bags: instead, the dust collects in a detachable, cylindrical collection vessel. Air and dust are blown at high speed into the collection vessel at a direction tangential to the vessel wall, creating a vortex. The dust particles and other debris move to the outside of the vessel by centrifugal force, where they fall because of gravity, and clean air from the center of the vortex is expelled from the machine after passing through a number of successively finer filters at the top of the container. The first filter is intended to trap particles which could damage the subsequent filters that remove fine dust particles. The filters must regularly be cleaned or replaced to ensure that the machine continues to perform efficiently. Since Dyson, several other companies have introduced cyclone models, including Hoover, and the cheapest model is no more expensive than a conventional cleaner.
In early 2000 several companies developed robotic "vacuum" cleaners. Some examples are Roomba, Robomaxx, Trilobite and FloorBot. These machines propel themselves in patterns across a floor, cleaning surface dust and debris into their dustbin. They usually can navigate around furniture and find their recharging stations. Most robotic "vacuum" cleaners are designed for home use, although there are more capable models for operation in offices, hotels, hospitals, etc. Some such as the Roomba are equipped with an impeller motor to create an actual vacuum.[2][3] By the end of 2003 about 570,000 units were sold worldwide.[citation needed]
In 2004 a British company released Airider, a hovering vacuum cleaner that floats on a cushion of air. It is claimed to be light weight and easier to maneuver (compared to using wheels), although it is not the first vacuum cleaner to do this - the Hoover Constellation predated it by at least 35 years.
There is a recorded example of a 1930s Electrolux vacuum cleaner surviving in use for over 70 years, finally breaking in 2008.[4]
[edit] How it works
A vacuum's suction is caused by a difference in air pressure. A pump reduces the pressure inside the tube. Atmospheric pressure then pushes the air through the carpet and into the tube, and so the dust is literally pushed into the bag.
Tests have shown that vacuuming can kill 100% of young fleas and 96% of adult fleas.[5]
[edit] Configurations
Vacuum cleaner configurations:
- Upright vacuum cleaners take the form of a cleaning head, onto which a handle and bag are attached. Upright designs usually employ a rotating brush-roll, which removes dirt through a combination of sweeping and vibration. There are two types of upright vacuums; dirty-fan/direct air, or clean-fan/indirect air.
The older of the two designs, dirty-fan cleaners have a large impellor (fan) mounted close to the suction opening, through which the dirt passes directly, before being blown into a bag. The motor is often cooled by a separate cooling fan. Due to their large-bladed fans, and comparatively-short air-paths, dirty-air cleaners create a very efficient airflow from a low amount of power, and make great carpet cleaners. Their 'above-floor' cleaning power is less efficient, since the airflow is lost when it passes through a long hose.
Clean-fan uprights have their motor mounted after the bag. Dust is removed from the airstream by the bag, and usually a filter, before it passes through the fan. The fans are smaller, and are usually a combination of several moving and stationary turbines working in sequence to boost power. The motor is cooled by the airstream passing through it. Clean-air vacuums are good for both carpet and above-floor cleaning, since their suction does not significantly diminish over the distance of a hose, as it does in dirty-fan cleaners. However, their air-paths are much less efficient, and can require more than twice as much power than dirty-fan cleaners to achieve the same results.
The most common upright vacuum cleaners use a drive-belt powered by the suction motor to rotate the brush-roll. However, a less common design of dual motor upright, often found in commercial vacuum cleaners, is available. In these cleaners, the suction is provided via a large motor, while the brush-roll is powered by a separate, smaller motor, which does not create any suction. The brush-roll motor can sometimes be switched off, so hard floors can be cleaned without the brush-roll scattering the dirt. It may also have an automatic cut-out feature, which shuts the motor off if the brush-roll becomes jammed, protecting it from damage.
- Canister (or cylinder) designs have the motor and bag in a separate canister unit (usually mounted on wheels) connected to the vacuum head by a flexible hose. Although upright units have been tested as more effective (mainly because of the beaters), the lighter, more maneuverable heads of canister models are popular. Some upmarket canister models have "power heads", which contain the same sort of mechanical beaters as in upright units, although such beaters are driven by a separate electric motor.
- Wet vacs or wet/dry vacuums—a specialized form of the canister vacuum—can be used to clean up wet or liquid spills. They commonly can accommodate both wet and dry soilage; some are also equipped with a switch or exhaust port for reversing the airflow, a useful function for everything from clearing a clogged hose to blowing dust into a corner for easy collection.
- Back-pack vacs are commonly used for commercial cleaning: they allow the user to move rapidly about a large area. They are essentially canister vacuum cleaners, except that straps are used to carry the canister unit on the user's back.
- Built-in or central vacuum cleaners move the suction motor and bag to a central location in the building and provide vacuum inlets at strategic places throughout the building: only the hose and pickup head need be carried from room to room; and the hose is commonly 8 m (25 ft) long, allowing a large range of movement without changing vacuum inlets. Plastic piping connects the vacuum outlets to the central unit. The vacuum head may either be unpowered or have beaters operated by an electric motor or air-driven motor. The dirt bag in a central vacuum system is usually so large that emptying or changing needs to be done less often, perhaps once per year. The central unit usually stays in "stand-by", and is turned on by a switch on the handle of the hose, or the unit powers up when the hose is plugged into the wall inlet. Such a unit also produces greater suction than common vacuum cleaners, because a larger fan and more powerful motor can be used when they are not required to be portable. Another benefit of a central vacuum system is that unlike a standard vacuum cleaner, which blows some of the dirt collected back into the room being cleaned (no matter how efficient its filtration), a central vacuum removes all the dirt collected to the central unit. Since this central unit is usually located outside the living area, no dust is recirculated back into the room being cleaned. In addition, because of the remote location of the motor unit, there is less noise in the room being cleaned than with a standard vacuum cleaner.
- Robotic vacuum cleaners move autonomously, usually in a mostly chaotic pattern ('random bounce'). Some come back to a docking station to charge their batteries, and a few are able to empty their dust containers into the dock as well.
- Small hand-held vacuum cleaners, either battery-operated or mains powered, are also popular for cleaning up smaller spills.
- Drum vacuums are used in industrial applications. With such a configuration, a vacuum "head" sits atop of an industrial drum, using it as the waste or recovery container. Electric and Compressed Air powered models are common. Compressed air vacuums utilize the venturi effect.
Most vacuum cleaners are supplied with various specialized attachments, tools, brushes and extension wands to allow them to reach otherwise inaccessible places or to be used for cleaning a variety of surfaces.
[edit] Exhaust Filtration
Vacuums by their nature cause dust to become airborne, by exhausting air that is not completely filtered. This can cause health problems since the operator ends up inhaling this dust. There are several methods manufactures are using to solve this problem. Some methods may be combined together in a single vacuum. Typically the filter is positioned so that the incoming air passes through it before it reaches the motor.
- Bag: The bag is the typical method to capture the debris vacuumed up. It involves a paper or fabric bag that allow air to pass though but attempts to trap all dust and debris in the bag.
- Cyclonic separation: Bagless vacuum cleaners tend to employ this method. It causes intake air to be cycled or spun so fast that the dust is forced out of the air and falls into a storage bin. The operation is similar to that of a centrifuge.
- Water Filtration: First seen commercially in the 1920s in the form of the Newcombe Separator (Later to become the Rexair Rainbow), water filtration vacuum cleaners use water as a filter. It forces the intake air to pass through water before it is exhausted. The idea behind this is that wet dust cannot be airborne. They filter out any debris that is water soluble and are considered very effective, but they require the water to be dumped and the machine rinsed out after every use.
- Ultra Fine Air filter: This method is used as a secondary filter after the air has passed thought the rest of the machine. It is meant to remove any remaining dust that could harm the operator.
[edit] Vacuum cleaner specifications
The performance of a vacuum cleaner can be measured by several parameters:
- airflow, in cubic feet per minute (CFM or ft³/min) or litres per second (l/s)
- air speed, in miles per hour (mph) or metres per second (m/s)
- suction, vacuum, or water lift, in inches of water or pascals (Pa)
The suction is the maximum pressure difference that the pump can create. For example, a typical domestic model has a suction of about negative 20 kPa. This means that it can lower the pressure inside the hose from normal atmospheric pressure (about 100 kPa) by 20 kPa. The higher the suction rating, the more powerful the cleaner. One inch of water is equivalent to about 249 Pa; hence, the typical suction is 80 inches (2,000 mm) of water.
The power consumption of a cleaner, in Watts, is often the only figure stated. Many North American vacuum manufacturers only give the current in amperes (e.g. "12 amps"[1]) and the consumer is left to multiply that by the line voltage of 120 volts to get the power ratings in Watts. The power does not indicate the effectiveness of the cleaner, only how much electricity it consumes. The amount of this power that is converted into airflow at the end of the cleaning hose is sometimes stated, and is measured in air watts: the units are simply watts; "air" is used to clarify that this is output power, not input electrical power. This is calculated using the formula:
| cleaning power (air watts) | = airflow (CFM) × suction (inches of water) / 8.5 |
| = airflow (m³/s) × suction (Pa) |
Air watts measured at the vacuum's motor can differ by as much as 50% (depending on the type of vacuum) from the air watts measured at the end of the hose. This is most noted in Central Vacuums.
Some smaller vacuum cleaners are light-weight, portable, and rechargeable, instead of using AC power.
[edit] Electric mop
Some vacuum cleaners include an electric mop in the same machine: for a dry and a later wet clean.
[edit] See also
[edit] Footnotes
- ^ In Britain Hoover has become so associated with vacuum cleaners as to become a genericized trademark. The word "hoover" (without initial capitalization) is often used as a generic term for "vacuum cleaner". Hoover is also used as a verb, as in "I've just hoovered the carpet".
- ^ Roomba diagnostic tests procedure. Accessed 2008-01-17.
- ^ Jack Perdue. Reassembling my Roomba. March 21, 2006. Accessed 2007-06-24.
- ^ "Vacuum cleaner lasts for 70 years", BBC News, 2008-01-27. Retrieved on 2008-01-28.
- ^ Cat Fleas' Journey Into The Vacuum Is A 'One-way Trip'
[edit] References
- The origin of the vacuum cleaner - H. Cecil Booth, Transactions of the Newcomen Society, 1934–1935, Volume 15.
- "Mr Booth's answer wasn't so dusty", Chichester Today
- Vacuum Cleaners - Energy Use - MTP
[edit] External links
