A steam mop is a mop that uses steam to clean floors and carpets. Unlike a regular mop, which requires cleaning agents such as bleach or detergent, the steam mop uses the heat from the steam to disinfect the floors. A microfibre pad is often placed right underneath the steam jet to trap dirt. Most steam mops have a small water tank, and often provide dry steam.

How a steam mop works[link]

A steam mop works by heating up the water inside the reservoir to temperatures of about 120 degrees Celsius. Many steam mops have one jet of dry steam (but may have as many as 15 jets), moistening a microfiber pad placed underneath. The steam helps soak the pad and dirt is drawn off ground. Unlike regular mops though, steam mops do not leave a residue on the floor and often clean through the dirt. The intense heat of the steam can kill about 99 percent of the bacteria and household dust mites. Steam mops can disinfect floors, restore shine, kill dust mites, and remove some stains.

Some of the steam mops feature a two-sided, flip mop head that allows you to clean twice as much floor before changing the mop pad. One pad is soft for use on delicate flooring such as hardwoods and laminates. The other pad has built-in scrubbing strips that make cleaning tough, stuck-on messes easy.

Safety[link]

While steam mops have advantages, the heat from the steam and electricity are safety issues. Steam can burn skin quickly. There have been recalls of steam mops related to burn hazards. ^{[1] [2]}

References[link]

Steam phase eruption of Castle Geyser in Yellowstone Park A temperature-versus-entropy diagram for steam A Mollier enthalpy-versus-entropy diagram for steam

Steam is the technical term for water vapor, the gaseous phase of water, which is formed when water boils. In common language it is often used to refer to the visible mist of water droplets formed as this water vapor condenses in the presence of cooler air. At lower pressures, such as in the upper atmosphere or at the top of high mountains water boils at a lower temperature than the nominal 100 °C (212 °F) at standard temperature and pressure. If heated further it becomes superheated steam.

The enthalpy of vaporization is the energy required to turn water into the gaseous form when it increases in volume by 1,600 times at standard temperature and pressure; this change in volume can be converted into mechanical work by steam engines and steam turbines. Steam engines played a central role to the Industrial Revolution and modern steam turbines are used to generate electricity. If liquid water comes in contact with a very hot substance (such as lava, or molten metal) it can create a steam explosion. Steam explosions have been responsible for many foundry accidents and may also have been responsible for much of the damage to the plant in the Chernobyl accident.

Types of steam and conversion[link]

Water vapor that includes water droplets is described as wet steam. As wet steam is heated further, the droplets evaporate, and at a high enough temperature (which depends on the pressure) all of the water evaporates and the system is in vapor-liquid equilibrium.^[1]

Superheated steam is steam at a temperature higher than its boiling point for the pressure which only occurs where all the water has evaporated or has been removed from the system.^[2]

Steam tables contain thermodynamic data for water/steam and are often used by engineers and scientists in design and operation of equipment where thermodynamic cycles involving steam are used. Additionally, thermodynamic phase diagrams for water/steam, such as a temperature-entropy diagram or a Mollier diagram shown in this article, may be useful. Steam charts are also used for analysing thermodynamic cycles.

enthalpy-entropy (h-s) diagram for steam	pressure-enthalpy (p-h) diagram for steam	temperature-entropy (T-s) diagram for steam

Uses[link]

Agricultural[link]

In agriculture, steam is used for soil sterilization to avoid the use of harmful chemical agents and increase soil health.

Domestic[link]

Steam's capacity to transfer heat is also used in the home: for cooking vegetables, steam cleaning of fabric and carpets, and heating buildings. In each case, water is heated in a boiler, and the steam carries the energy to a target object. "Steam showers" are actually low-temperature mist-generators, and do not actually use steam.

Electricity generation (and cogeneration)[link]

About 90% of all electricity is generated using steam as the working fluid, nearly all by steam turbines.^[3]

In electric generation, steam is typically condensed at the end of its expansion cycle, and returned to the boiler for re-use. However in cogeneration, steam is piped into buildings through a district heating system to provide heat energy after its use in the electric generation cycle. The world's biggest steam generation system is the New York City steam system which pumps steam into 100,000 buildings in Manhattan from seven cogeneration plants.^[4]

Energy storage[link]

Fireless steam locomotive
Despite the resemblance to a boiler, note the lack of a chimney and also how the cylinders are at the cab end, not the chimney end.

In other industrial applications steam is used for energy storage, which is introduced and extracted by heat transfer, usually through pipes. Steam is a capacious reservoir for thermal energy because of water's high heat of vaporization.

Fireless steam locomotives were steam locomotives that operated from a supply of steam stored on-board in a large tank resembling a conventional locomotive's boiler. This tank was filled by process steam, as is available in many sorts of large factory, such as paper mills. The locomotive's propulsion used pistons and connecting rods, as for a typical steam locomotive. These locomotives were mostly used in places where there was a risk of fire from a boiler's firebox, but were also used in factories that simply had a plentiful supply of steam to spare.

Lifting gas[link]

Owing to its low molecular mass, steam is an effective lifting gas, providing approximately 60% as much lift as helium and twice as much as hot air. It is not flammable, unlike hydrogen, and is cheap and abundant, unlike helium. The required heat, however, leads to condensation problems and requires an insulated envelope. These factors have limited its use thus far to mostly demonstration projects.^[5]

Mechanical effort[link]

A steam engine and steam turbines use the expansion of steam to drive a piston or turbine to perform mechanical work. The ability to return condensed steam as water-liquid to the boiler at high pressure with relatively little expenditure of pumping power is important. Condensation of steam to water often occurs at the low-pressure end of a steam turbine, since this maximizes the energy efficiency, but such wet-steam conditions have to be limited to avoid excessive turbine blade erosion. Engineers use an idealised thermodynamic cycle, the Rankine cycle, to model the behavior of steam engines. Steam turbines are often used in the production of electricity.

Sterilization[link]

An autoclave, which uses steam under pressure, is used in microbiology laboratories and similar environments for sterilization.

Steam in piping[link]

Steam is used in piping for utility lines. It is also used in jacketing and tracing of piping to maintain the uniform temperature in pipelines and vessels.

Wood treatment[link]

Steam is used in the process of wood bending, killing insects and increasing plasticity.

Concrete treatment[link]

Steam is used to accentuate drying especially in prefabricates.

Cleaning[link]

Used in cleaning of fibers, sometimes prior to painting.

See also[link]

Look up steam in Wiktionary, the free dictionary.

Wikimedia Commons has media related to: Steam

Wikimedia Commons has media related to: Water vapor

• Electrification
• Food steamer or steam cooker
• Geyser—geothermally-generated steam
• IAPWS—an association that maintains international-standard correlations for the thermodynamic properties of steam, including IAPWS-IF97 (for use in industrial simulation and modelling) and IAPWS-95 (a general purpose and scientific correlation).
• Industrial Revolution
• Live steam
• Mass production
• Nuclear power—and power plants use steam to generate electricity
• Oxyhydrogen
• Psychrometrics—moist air/vapor mixtures, humidity and air conditioning
• Steam locomotive

References[link]

External links[link]

• Steam Tables & Charts by National Institute of Standards and Technology, NIST
• What Is Steam? (general article about the properties of water/steam)
• Steam Tracing
• Online steam properties calculator (Spirax Sarco)
• Free Steam Tables Online calculator based on IAPWS-IF97 (MegaWatSoft)
• Online Steam Tables Calculator based on IFC-67
• freesteam a free (GPL) library for calculation of steam properties using the IAPWS-IF97 standard.
• JSteam A Windows library and free calculator for the calculation of steam properties using the IAPWS-IF97-07 standards.
• JSteam Excel Add In An Excel add in for modelling and solving steam utility systems using the JSteam library.

This article may require cleanup to meet Wikipedia's quality standards. No cleanup reason has been specified. Please help improve this article if you can; the talk page may contain suggestions. (November 2009)

A mop in a bucket with its dryer

A mop (such as a floor mop) is a mass or bundle of coarse strings or yarn, etc., or a piece of cloth, sponge, or other absorbent material, attached to a pole or stick. It is used to soak up liquid, for cleaning floors and other surfaces, or to mop up dust, or for other cleaning purposes. The word (then spelled mappe) is attested in English as early as 1496, but new refinements and variations of mop designs have been introduced, from time to time. For example, American inventor Jacob Howe received U.S. patent #241 for a mop holder in 1837 ^[1] and African American inventor Thomas W. Stewart (U.S. patent #499,402) in 1893.^[2]

Types[link]

Classic yarn mop for wet use[link]

A classic round yarn mop for wet use

Mop, drying

In daily speech, the term "mop" has been used in reference to a yarn mop. The mop (eye) consists of thick lengths of yarn (about 25 cm / 10 in) or, in newer models, soft strands of water-absorbing fabric. A yarn mop is usually mounted on a long (about 1.5 m or 5-foot) handle with a threaded-screw end on which the mop can be fastened by turning it clockwise.

To clean a floor, the mop is soaked in a bucket of water, into which some cleaning solution has usually been added, and swept against the floor surface. Some buckets include a wringer to strain excess water from the mop, to control the amount of water transferred to the floor. Leaving excess (contaminated) water on the floor will result in a dirty residue.

Dry-mop, dust-mop[link]

Flat mop for dry or wet (pre-moisting) use. Open end yarn with microfiber. Velcro back.

A dry-mop or dust-mop is designed to pick up dry, loose contamination such as dust, earth and sand from the surface of the floor. It consists of yarn and/or microfiber and is used as a first step in cleaning a floor.

Professional dry mops consist of a flat sheet of micro fiber textile or sheets with a surface of looped yarn, usually about 15 cm wide, and comes in variable lengths (usually 30 – 100 cm).

The dry-mop can in many instances replace a broom and has the ability to hold a limited amount of dust or sand within itself. Ideally, it should be machine washed when it becomes saturated with dust. Another option is using a vacuum cleaner to suck surface dust away from the mop, however this is limited in its effectiveness.

Single-use dry-mops are also available and widely sold.

Wet-mop, moist-mop[link]

A wet mop or moist mop is, in professional cleaning, used as in the second step in the cleaning of a surface. The wet mop is swept over the surface to dissolve and absorb fat, mud and dried-in liquid contaminations. Professional wet-mops consist of a flat sheet of microfiber textile or a sheet with a surface of looped yarn (which might contain microfiber as well), usually about 15 cm wide, and come in various lengths (usually 30 – 100 cm).

• 

  Flat wet-mop (pre-moisting). Looped microfiber with velcro mounting on back.

• 

  Flat wet-mop (back view of previous mop).

• 

  Flat mop for dry or wet (pre-moisting) use. Open-end microfiber with looped yarn edges. Velcro back.

Mops for pre-moisting[link]

Manual pre-moisting of wet-mops in bucket.

Professional flat mops are made for pre-moisting. Mops are pre-impregnated with an ideal amount of water mixed with an appropriate amount detergent. This means that the cleaner does not need to bring any additional water on the cleaning trolley. This ideal amount is often recommended by the manufacturer in terms of weight percent of water per weight of the dry mop, for example "175% water per weight of the dry mop".

Mops for pre-moisting are flat sheets of (often microfiber) textile, usually about 15 cm wide, and comes in variable lengths (usually 30 – 100 cm). Mops for pre-moisting are fastening on a handle with a flat pad mount with the aid of velcro or a pouch on the mop, in which the pad on the handle fits.

Pre-moisting[link]

Pre-moisting can be done with a special washing machine or by hand by simply folding and packing the mops tight in a container and pouring the measured amount of water over them. The mops will then need about 5 – 10 minutes for the liquid to distribute evenly in their tissue before use.

Advantages[link]

• The cleaner does not have to have a bucket of water with him/her when sweeping the floor, but simply carries an appropriate number of mops. This means the weight of the equipment can often be kept lower.
• The risk of over-wetting the floor and leave pools which collect dust is eliminated if the wetting is ideal.

Hot mop[link]

The hot mop (or steam mop) follows a similar concept to a steam iron. After adding water, the water is heated to make it exude on top of a floor, which can then be cleaned without using a cleaning solvent. These can work best on surfaces where a regular mop would also be used, such as bare floors, hearths, and laminate.

Syntho-mop[link]

A syntho-mop such as the Scooba is not considered a mop, because even though it performs the same function as a traditional mop, the lack of hand operation makes it ineligible for status as a mop.^[3]

Handles and mounting[link]

Mop handles From left: Classic yarn mop handle made of aluminium (thread mount), unadjustable aluminium handle for velcro mop (50 cm), unadjustable aluminium handle for velcro mop (60 cm), scale included for reference.

A mop handle consists of a long piece of wood or aluminium tubing fitted with a specific mount for the mop. The handle can be attached for mounting a mop on it by means of:

• screwing (as with the classic yarn mop)
• velcro (as with many professional flat mops)
• pouch (as with many professional flat mops)
• clamp
• hanger (with strands doubled over the hanger)
• plastic claws (attached to the strands)

Detail of mop mounting piece (blue plastic) and mount

Velcro mop with mount

Traditional construction[link]

In her book “Maggie's Memories” Margaret Wadkin (late of Hickling, near Melton Mowbray) describes the use of a mop nail for constructing home made mops from old pieces of cloth during her village childhood in the early 20th century. "The mop nail was made by the blacksmith (if there are any still around, they will be antiques). This nail was several inches long with a point at the end and a flat head a couple or so inches wide., we would stand the nail on its flat head, cut pieces of old material into squares and push over the sharp end of the nail and when enough fix a piece of leather, then push the sharp point into the mop stale or handle. There was a knack of twisting these mops over the wrist to swish away surplus water, every woman could use one of these useful mops."^[4]

See also[link]

• Broom
• Bucket
• Floor buffer

References[link]

Wikimedia Commons has media related to: Mops