有关真空吸尘器方面的英语资料
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发布时间：2022-04-22 05:31
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时间：2023-10-21 06:24
简介
Technology
A vacuum's suction is caused by a difference in air pressure. A pump reces the pressure inside the tube. Atmospheric pressure then pushes the air through the carpet and into the tube, and so the st is literally pushed into the bag.
Tests have shown that vacuuming can kill 100% of young fleas and 96% of alt fleas.
使用的科技
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 al 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 st 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 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 proces 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 st 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.
The iRobot Roomba Discovery Robotic vacuum cleaner operates autonomously.
The iRobot Roomba Discovery Robotic vacuum cleaner operates autonomously.
* 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 st 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 instrial applications. With such a configuration, a vacuum "head" sits atop of an instrial 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.
结构
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") 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.
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