- Hot water extraction
The Hot Water Extraction (HWE) method, is a method used in chemistry for extraction and for "
steam cleaning" (e.g.carpet s. as listed by theIICRC to be the primary method for cleaning carpets. Residential, and Commercial). The pressurised hotwater extraction (PHWE) process uses a combination of high waterpressure for agitation, and hot water to increase reaction rate."Steam Cleaning"
Though commonly called "Steam Cleaning", no actual steam is involved in the HWE cleaning process, apart from steam that may escape incidentally from hot water. When the cleaning solution comes in contact with the carpet/rug, it is anywhere between 120-250 degrees Fahrenheit, according to the heat available from the cleaning unit. For instance, in a modern
truck -mounted carpet cleaning machine, water can be heated to 300+ degrees (F), but after passing through high pressure steel braided hose and severalmanifold s, the water loses much of itsheat .The typical cleaning method involves a preconditioning of the soiled surface with an alkaline (7 or above on the
pH Scale ) agent, followed by light agitation with a groomingbrush and appropriate dwell time. Next, thesurface is passed over several times with a cleaning tool (either manual or automatic) to thoroughly rinse out the preconditioner and, using an acetic acid solution, lower thepH of the fibres to a neutral state. Finally, the surface is dried sufficiently to avoid any possibility of saturation. Inexperienced carpet cleaning companies sometimes over-wet carpeting, which can lead tomold and recurringstain s.References
* Pressurized Hot Water Extraction Coupled On-line with LC-GC: Determination of Polyaromatic
Hydrocarbon s inSediment , Anal. Chem., 72 (14), 3070 -3076, 2000.ee also
*
Cold water extraction
*Solubility
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