Vacuum cleaner and Washing machine
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A vacuum cleaner (colloquially in the UK, Hoover after one of the
major brands) is a device that uses an air pump to create a partial
vacuum to suck up dust and dirt, usually from carpeted floors. Most
homes with carpeted floors in developed countries possess a domestic
vacuum cleaner for cleaning. The dirt is collected by a filtering
system or a cyclone for later disposal.Vacuum cleaner
configurations:Upright vacuum cleaners have the pump mounted directly above the
suction intake, with the bag mounted on the handle, which rises to
about waist height. Upright designs usually employ mechanical
beaters, often rotating brushes, to help disturb dust to be vacuumed
up; these beaters are usually driven by a belt attached to the
vacuum motor. |
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 up market
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 un-powered 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.
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
electric, are also popular for cleaning up smaller spills.
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.
The first hand-powered cleaner using vacuum principles may have been
the "Whirlwind", invented in Chicago in 1865.
The first powered cleaner employing a vacuum was patented by H.
Cecil Booth, a British engineer, 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 it and sucking hard. Upon seeing the dust and dirt
collected on the underside of the handkerchief he realized the idea
could work. Booth worked to create a device operating on such
principles, and patented such a machine in Britain: the large
device, known as the Puffing Billy, was drawn by horses and parked
outside the building to be cleaned; suction was then provided by an
internal-combustion engine burning petrol (gasoline). Booth never
achieved great success with his invention.
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.
A washing machine
A washing machine is a machine designed to clean laundry, i.e.
clothing and other household textiles such as towels and sheets. The
term is generally applied only to machines that use water as the
primary cleaning solution, as opposed to dry cleaning (which uses
alternative cleaning fluids, and is generally performed by
specialist businesses) or even ultrasonic cleaners.
The first British patent under the category of Washing and Wringing
Machines was issued in 1691. A drawing of an early washing machine
appeared in the January 1752 issue of "The Gentlemen's Magazine," an
English publication. In 1782 Henry Sidgier was issued a British
patent for a rotating drum washer.
The first United States Patent titled "Clothes Washing" was granted
to Nathaniel Briggs of New Hampshire in 1797. However, there is no
drawing or description of the patent so whether it was for a washing
machine or something else related to washing, remains a mystery.
The electric washing machine was first mass produced in 1906. It is
not known who first "invented the electric" washer. A.J. Fisher has
been incorrectly credited with the invention of the electric washer.
The US patent office shows at least one patent issued before Mr.
Fisher's for a washing machine with an electric motor. The first
automatic washer was introduced by Bendix in 1937.
Contemporary washing machines are available in two main
configurations: "top loading" and "front loading". The "top loading"
design, most popular in the United States, Australia and some parts
of Europe, places the clothes in a vertically-mounted cylinder, with
a propeller-like agitator in the center of the bottom of the
cylinder. "Top loading" machines in Asia use impellers instead of
agitators. Impellers are similar to agitators except that they don't
have the center post extending up in the middle of the wash tub
basket. Clothes are loaded through the top of the machine, which is
covered with a hinged door. The "front loading" design, most popular
in Europe and the Middle East, instead mounts the cylinder
horizontally. Loading is through a glass door at the front of the
machine. The cylinder is also called the drum. Agitation is supplied
by the back-and-forth rotation of the cylinder, and by gravity. The
clothes are lifted up by paddles in the drum and then dropped. This
motion flexes the weave of the fabric and forces water and detergent
solution through the clothes load. Although more infrequent, there
is also a variant of the horizontal axis design that is loaded from
the top, through a small door in the circumference of the drum.
These machines usually have a shorter cylinder and are therefore
smaller.
All washing machines work by using three different sources of
energy. They use mechanical energy, thermal energy, and chemical
action. Mechanical energy is imparted to the clothes load by the
rotation of the agitator in "top loaders", or by the tumbling action
of the drum in "front loaders". Thermal energy is supplied by the
temperature of the wash bath. Many "front loading" machines have
electrical heating elements to heat the wash bath to near boiling.
Chemical action is supplied by the detergent and other laundry
chemicals. "Front loaders" use special detergents that are designed
to release different chemical ingredients at different temperatures.
This is so that different type of stains and soils will be cleaned
from the clothes as the wash water is heated up by the electrical
heater. "Front loaders" also need to use low sudsing detergents
because the tumbling action of the drum folds air into the clothes
load that can cause over sudsing.
Tests comparing front-loading and top-loading machines have shown
that, in general, front-loaders wash clothes more thoroughly, cause
less wear, and use less water and energy than top-loaders. As a
result of using less water, they require less detergent to be used,
or conversely, they can use the same amount of detergent with less
water, which increases detergent concentration and increases the
amount of chemical action. They also allow a dryer to be more easily
mounted directly above the washer. Top-loaders do have the advantage
in that they complete a washing cycle much faster, tend to cost less
for the same capacity machine, and allow clothes to be removed at
intermediate stages of the cycle (for instance, if some clothes
within a wash are not to be spun). They also tend to be easier to
load and unload, since reaching into the tub does not require
stooping the way a front-loader requires. The top-loader's spin
cycle between washing and rinsing allows an extremely simple passive
fabric softener dispenser, which must be accomplished by a
solenoid-operated valve on a front-loader. Another advantage to the
top-loading design is the reliance on gravity to contain the water,
rather than potentially trouble-prone or short-lived front door
seals. In the late 1990s, the British inventor James Dyson launched
a type of washing machine with two cylinders rotating in opposite
directions; which, it is claimed, reduces the wash time and produces
cleaner results.
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