Clean and dirty

As mentioned earlier, the system curve with the clean and dirty filters should coincide within the sweet zone of the pump on its curve. (Figure 8-20 and Figure 8-21). 

Remove protective clothing in a changing area provided with wash basin, and lockers for clean and dirty clothing. 

Building areas within the same room (with no physical partitions) having different requirements for air cleanliness ( clean and dirty areas) located on the same level (Fig. 7.107d). 

To control air and contaminant movement between zones, different construction, process-related, and ventilation techniques are used. Clean and dirty areas can be separated using solid walls, curtains, or partitions (Fig. 7.109(2). Ventilation techniques used to separate zones include... 

Ganapathy, V, Nomograph Relates Clean and Dirty Heat Transfer Coefficients, Fouling Factor, Heating/Piping/Air Conditioning, Jan. (1979) p. 127. 

This type of blade is well suited to streamline flow conditions and is used extensively on ventilating, air conditioning, and clean and dirty process gas streams. The backward blade does not catch dirt easily. The outstanding and important characteristic is the nonoverloading horsepower. This is the only commonly used blade style with this feature. It is important in process control and eliminates the need for oversized motors or other drivers. Speed of operation is high, which allows direct or belt connection to the driver. Certain streamlined blade designs provide the same basic characteristics with more efficient and quieter operation. The usual... 

As a filter element collects dust, the air resistance through it will rise, to a point where the system air flow is impaired. Users need to have an objective indication of this limit, and all filters except those on small package units should be fitted with manometers (see Figure 2 7.2). On installation, marks should be set to indicate clean and dirty resistance pressure levels. 

In summary, therefore, the KS suspension test differs from the RW and CM tests in that it is a capacity test, it reports the data as a pass or fail and not as a numerical cipher, i.e. not as a coefficient, and it uses a range of microorganisms. It combines an individual feature ofthe RW and CM tests in that it can report on disinfectant activity under both clean and dirty conditions. 

Tew, T. (1987). A comparison of small animal responses to clean and dirty trzps.Journal of Zoology (London) 212,361-364. 

A senes of dirty-water trials was carried out with levels of inlet contamination ranging from 408 ppm to 13.98% oil. It was not possible to achieve 40 ppm in every case, resulting predominantly from the reject rate not being high enough because in some cases the volume of oil in the feed exceeded the reject rate. Typical results for both the clean- and dirty-water trials are shown in Table 1 and Fig. 8. 

Vortex meters are being employed increasingly because of their accuracy, range, precision and relative insensitivity to fluid properties. They can be used for gases, saturated and superheated steam, low viscosity clean and dirty liquids, and cryogenic fluids 6 . They are not recommended for use when Re < 104. 

Recovery of a certain fraction is the ratio between the masses of any fraction in the suitable product and in the original material. The recovery shows which part of useful particles contained in the feed gets into a suitable product. The coarse and fine fraction recoveries are expressed by yc = mcCc/m0C0, yf = mfFf/m0F0, respectively. Cleanness and dirtiness characterize quality of the separated products. In contrast, fraction recovery characterizes the separation efficiency. In particular if the original product is composed only of particles having cut size, its fraction recovery is 50%. 

Fouling factors must be obtained experimentally by determining the values of U for both clean and dirty conditions in the heat exchanger. The fouling factor is thus defined as... 

Careful attention must be given to material flow patterns for clean and dirty equipment to prevent cross contamination. In larger facilities, the equipment wash room may be a separate room proximate to the preparations area with defined flows for materials and personnel. Ideally, materials should move through the facility in a unidirectional fashion, with no cross over of any kind. 

Figure 4. Classification of chert into very clean, clean, and dirty on the basis of relative amounts of Al and Ti.

Site environmental conditions may be particularly bad, e.g. deserts where sand storms are frequent offshore where rain storms are frequent and long lasting. The more filtering that is required, the more will be the pressure lost across the filters, both during clean and dirty operation. This pressure drop causes a loss of power output from the machine. 

The Rideal Walker and Chick Martin tests have been replaced by the Kelsey-Sykes test which assesses the disinfectant at its in use concentration under both clean and dirty conditions. There is a considerable amount of preparation involved and the tests are probably best carried out in specialist laboratories. 

It should be noted that the convention in the European bond markets is to quote the clean price and then calculate the accrued interest to obtain the dirty price. However, we want to emphasize that the answer is the same regardless of the order in which clean and dirty prices are calculated. ... 

Separate clean and dirty lockers should be provided for each operator. 

Some high-risk facihties require air locks, changing rooms equipped with showers with clean and dirty sides, or special equipment to decontaminate materials entering or leaving the facihty. The doors to the air locks should be separated by at least 7 feet to prevent both doors from being open simultaneously... 

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