Archive for January, 2011

The Development of the Diesel Engine

The most outstanding feature of the diesel engine is its efficiency. By compressing air rather than using an air-fuel mixture, the diesel engine isn’t limited by the preignition problems that affect high-compression spark-ignition engines. Thus, higher compression ratios may be achieved with diesel engines than with the spark-ignition type; equally, higher theoretical cycle efficiencies, when compared with the latter, can often be realized.

It ought to be noted that for a given compression ratio the theoretical efficiency of the spark-ignition engine is more than that of the compression-ignition engine; however, in practice it is possible to operate compression-ignition engines at compression ratios high enough to produce efficiencies greater than those attainable with spark-ignition systems. In addition, diesel engines don’t rely on throttling the intake mixture to control power. Therefore the idling and reduced-power efficiency of the diesel is far superior to that of the spark-ignition engine.

The principal drawback of diesel engines is the emission of air pollutants. These engines typically discharge high levels of particulate matter (soot), reactive nitrogen compounds (commonly designated NOx), and odour, compared with spark-ignition engines. Consequently, in the small-engine category, consumer purchase is low.

A diesel engine is started by driving it from some external power source until conditions have been established by which the engine can run by its own power. The easiest starting method is to admit air from a high-pressure source, about 1.7 to nearly 2.4 megapascals, to each of the cylinders in turn on their normal firing stroke. The compressed air becomes heated sufficiently to ignite the fuel.

Other starting methods include auxiliary equipment and include releasing blasts of compressed air to an air-activated motor geared to rotate a large engine’s flywheel; supplying electric current to an electric starting motor, similarly geared to the engine flywheel; and applying a small gasoline engine geared to the engine flywheel. The selection of the most suitable starting method depends on the physical size of the engine to be started, the type of the connected load, and whether or not the load is able to be disconnected on starting.

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Which method of carpet cleaning gets the best results?

carpet cleaning brisbaneCarpet is such a valuable addition to any Brisbane home, but just like all fibre products, the beauty and life of a carpet mainly depends on proper cleaning and maintenance.

Generally, proper carpet care involves regular vacuuming and cleaning using these techniques: shampooing, foam cleaning, dry cleaning, bonnet cleaning, and steam cleaning, or hot water extraction.

Now, the question is, which one of these techniques deliver the best results? Most carpet manufacturers, including professional carpeting and cleaning organisations, are unanimous with their answers.

They state that steam cleaning or hot water extraction is the most thorough way to clean even the grummiest carpet. Steam cleaning is the most common technique used by professionals. In fact the Australian Standard even states that other methods are only interim cleaning methods and that hot water extraction is the primary method.

Steam cleaning uses a hot water cleaning solution that is sprayed on the carpet via a high pressure jet spray. A truck-mounted or portable machine is then used to thoroughly extract the solution (together with the dissolved dirt). However, note that the truck-mounted equipment is more powerful than the portable one and should be used where possible.

Steam cleaning also consists of a number of phases – from pre-vacuuming to eliminate the dry soils in the carpet before wetting and turning to mud, treating stains and spots (if any), pre-spraying with a cleaning solution, agitation (hand or machine operated) of the cleaning solution into the carpet, hot water extraction, rinsing with a neutralising aid, and speed drying.

But why is it considered the best? Because only steam cleaning does the following:

  • The high amount of heat it uses kills bacteria, molds, fungus, and dust mites, making it the most hygienic process to clean carpets.
  • It doesn’t leave any residue if done correctly, making your carpet soft, fresh and clean.
  • It is the only method that has the vacuuming process used the entire time which means more “nasties” are removed from your carpet.

As we all know, carpets are very expensive – so you want them to always be in great condition and to last as long as possible.
Highly recommended by professionals, steam carpet cleaning is the best way for you to maintain your valuable investment in soft floor coverings.
Now that we know the best method for keeping your carpets clean the question most asked is how long will my carpets take to dry after cleaning?

The time frame for carpets to be totally dry depends on several things, such as the level of soiling and the cleaning method used. Generally, it can be anywhere from 30 minutes to 12 hours. The Australian Standard states that up to 24 hours is acceptable.

If you use steam cleaning or hot water extraction by a professional, drying should take 2 hours to 12 hours. Take into consideration the following factors to determine how long it will take for your carpet to dry, and what you can do to make it dry much faster.

The type of fibre- This is by far the most important thing. Wool carpets take a lot longer to dry then synthetics. Wool carpets are about 30 % absorbent compared to the few percent range for synthetics.

Thickness and Weight of the Carpet – The thicker the carpet, the longer time it will need to dry.

Exposure to Air – If your room doesn’t have windows, or if the windows are shut, to create ventilation, evaporation will be lessened. Turn on the fan in your room to improve air circulation, making your carpet dry faster. During warmer months, turn on the air conditioner instead.

The Humidity and Weather conditions- Obviously the higher the humidity the longer it will take for carpets to dry. Is it a hot fine day or a cold wet day for example?

Now, if you really need your carpet to dry at a much faster rate, opt for professional carpet cleaners that offer speed drying services on top of state of the art equipment and years of experience.

Carpet Cleaning Brisbane specialise in carpet cleaning Brisbane as well as other associated services. Carpet Cleaning Brisbane are highly trained, professional Brisbane carpet cleaners.