Filter characteristics

The softened seawater is fed with dry or slaked lime (dolime) to a reactor. After precipitation in the reactor, a flocculating agent is added and the slurry is pumped to a thickener where the precipitate settles. The spent seawater overflows the thickener and is returned to the sea. A portion of the thickener underflow is recirculated to the reactor to seed crystal growth and improve settling and filtering characteristics of the precipitate. The remainder of the thickener underflow is pumped to a countercurrent washing system. In this system the slurry is washed with freshwater to remove the soluble salts. The washed slurry is vacuum-filtered to produce a filter cake that contains about 50% Mg(OH)2. Typical dimensions for equipment used in the seawater process may be found in the Hterature (75). 

Slurry-settling characteristics Slurry-filtering characteristics... 

From the viewpoint of accommodation to the filter-supporting structure, some cloths cannot be used, even though the filtering characteristics are excellent. For rotary drum filters, for example, the cloth is pressed onto the drum by the caulking method, which uses cords that pass over the drum. In this case, the closely woven cloths manufactured from monofilament polyethylene or polypropylene fiber are less desirable than more flexible cloths of polyfilament fibers or staple cloths. 

The CFPP was developed in 1965-66 to predict the low-temperature filterability performance of diesel fuels. This method is commonly used throughout the world to quickly determine low-temperature fuel filterability characteristics. In more recent... 

Data collected for each run included acid analysis using inductively coupled plasma (ICF) to determine cation concentration and titration to determine H concentration. Filtering characteristics were determined using solid and filtrate yield rates, as well as back pressures during the filtration cycle. The filter cake was characterized by moisture content and composition. Solid samples were analyzed with scanning electron microscopy (SEM) to determine changes in particle shape and size under various process conditions, and X-ray diffraction (XRD) was used to determine the solids composition. 

Figure 3.7. Unit-step responses of an instrument (a) and of a high-frequency filter (b) in the same frequency range 1 - no filter 2 - with a filter 3 - ideal filter characteristic 4 - approximation by a second order Butterworth filter.

Especially in the case of low bit-rates (implying that a lot of quantization noise is introduced), the filter characteristics of the analysis and synthesis filters as determined by the prototype window / windowing function are a key factor for the performance of a coding system. 

Other window functions than the sine window have been proposed as well (see [Bosi et al., 1996b, Fielder et al., 1996]). Using Kaiser-Bessel-Derived window functions, a filter characteristic exhibiting better side-lobe suppression is possible. This is explained in [Fielder et al., 1996],... 

Houtgast, 1977] Houtgast, T. (1977). Auditory-filter characteristics derived from direct-masking data and pulsation-threshold data with rippled-noise masker. J. Acoust. Soc. Am., 62 409 115. 

Considering the similarity of the curves presented in Figures 12 and 13 and the fact that octocrylene has filtering characteristics (which are very different from MBC both in wavelength and in extinction capacity) it is obvious that the... 

Atypical HMX batch process starts with a reactor that contains acetic acid. The proper amounts of hexamine in glacial acetic acid, ammonium nitrate in nitric acid, and acetic anhydride are added in stages. The HMX slurry is transferred to the aging tanks, held for 30 min at 44°C, and pumped to a simmer tank where sufficient dilution liquor is added to reduce the concentration to 80 percent acetic acid. After dilution the temperature is raised to 110°C, to decompose undesirable by-products and to improve the filtering characteristics of the HMX. 

Temperature Requirements of a Process. The temperature of filtration may affect the viscosity of the fluid, the corrosion rate of the housing, and filter medium compatibHity. Elevated temperatures tend to accelerate corrosion and may weaken the gaskets and seals of filter housings. In general, the viscosity of fluids decreases with increasing temperature. EHtration of highly viscous fluids maybe conducted at elevated temperature (8). For example, pharmaceutical products containing oil or a Hpid emulsion as a dmg carrier may require filtration at elevated temperature to enhance filterability characteristics. 

The normal method of separation is filtration. The division between dissolved and particulate thus becomes a function of pore size and filtering characteristics of the particular filter chosen. The pore size... 

A distinction is made between technical and methodological calibration. Technical calibration is based on process technology modules (dosage unit, thermostat) and on modules of the technique of measurement (filter characteristics of photometer). Methodological calibration is employed in the analytical method. It is the aim of methodological calibration that the data obtained have narrow tolerance limits of scatter around a target value. A prerequisite for this that the technical calibration is accurate within prescribed tolerance limits. 

Chicago Sanitary District (14) reported an effluent suspended solids of 6-8 mg/L and a BOD of 3.5-5 mg/L when applying a good quality (suspended solids = 20-25 mg/L and BOD 15-20 mg/L) activated sludge effluent to a 23- tm screen. Removal efficiencies as recommended for secondary effluents are presented in Table 3(10). The efficiency of a microstrainer is determined by the hydraulic and solids loadings as well as by the filtering characteristics of the influent. Microstrainers will not remove colloidal material or small (micron-size) algae. Microstrainers are also adversely affected by fluctuations in influent composition and quality. 

Figure 4.4 Similar to the sliding polynomial smoothing (Savitzky Golay filter, the coefficients for 2nd order fit to a parabola) is the effect of Bromba Ziegler filters [Bromba and Ziegler, (1983c), coefficients fit to a triangle upper figure]. Both have bad low pass filter characteristics, as shown in the lower figure with the Fourier transforms of filters through 21 points each.

TABLE 48—11. Drug Disposition during Dialysis Depends on Filter Characteristics... 

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