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Feed water characteristics

Besides feed water characteristics andproduct water quality, capital costs (CAPEX) and operating costs (OPEX), manpower, space avaUabihty, and future expansion requirements, and... [Pg.85]

Feed-water characteristics - Temperature >25°C, high amounts of organic and inorganic nutrients, large number of cells (> 10 colony-forming units per ml), and high SDI. [Pg.133]

The feed water characteristics are filled into the Feed Water section as shown in Figure 10.9. Ihe cations, anions and inerts are specified in different panels. WAVE also has a Quick-entry option to enter a desired NaCl concentration. In addition to ionic composition, the WAVE user is encouraged to input information on water solid content including NTU (Nephelometric Turbidity Unit), SDI (Silt Density Index) and TSS (Total Suspended Solids) as well as the organic content (in TOC or Total Organic Content). These are used to identify appropriate design guidelines for the user. [Pg.263]

Operating parameters of this German plant, on the basis of one cubic meter of raw gas, iaclude 0.139 m O2, 0.9 kg briquettes, 1.15 kg steam, 1.10 kg feed water, 0.016 kWh, and 1.30 kg gas Hquor produced. Gasifier output is 1850 m /h and gas yield is 1465 m /t dry, ash-free coal. The coal briquettes have a 19% moisture content, 7.8% ash content (dry basis), and ash melting poiat of 1270°C. Thermal efficiency of the gas production process is about 60%, limited by the quaHty and ash melting characteristics of the coal. Overall efficiency from raw coal to finished products is less than 50%. [Pg.159]

Using the example of Reference [6], assume a pump with characteristic curve and added temperature rise data as showm on Figure 3-59 is to handle boiler feed water at 220°F, with a system available NPSH = 18.8 feet. The v apor pressure of w ater at 220°F is 17.19 psia from steam tables and the SpGr = 0.957. Correcting the 18.8 feet NPSHa psia = 18.8 (l/[2.31/0.957)] = 7.79 psia at 220°F. [Pg.209]

BSI recommended water characteristics for shell boilers (FT boilers) up to 30 bar (435 psig) note that when copper alloys are present in the feed system, the pH should not exceed 9.2 if corrosion of these materials is to be avoided. [Pg.583]

In the table of recommended water characteristics for nonfired water tube boilers, BSI proposes that plants containing copper alloys in either the feed or condensate system should have a FW pH limited to 8.5 to 9.2. If the feed system is completely ferrous, the pH should be limited to 9.2 to 9.5. For plants utilizing the FW for spray attemperation or desuperheating, the pH should be controlled with volatile alkalis only. [Pg.589]

Table 12.13 (BS 2486 1997 table 5) Recommended water characteristics of feed water at economizer inlet for once-through boilers... Table 12.13 (BS 2486 1997 table 5) Recommended water characteristics of feed water at economizer inlet for once-through boilers...
Abstract This chapter discusses the characteristics of membrane concentrate, and the relevance that the concentrate has on the method of disposal. Membrane concentrate from a desalination plant can be regarded as a waste stream, as it is of little or no commercial benefit, and it must be managed and disposed of in an appropriate way. It is largely free from toxic components, and its composition is almost identical to that of the feed water but in a concentrated form. The concentration will depend on the type of desahnation technology that is used, and the extent to which fresh water is extracted from the brine. Based on the treatment processes that are used, a number of chemicals may also be present in the concentrate, albeit in relatively small quantities. [Pg.14]

PCA 16 (Belclene 161 series) are 35 to 50% active, low phosphorus content materials that have found application in very high stress cooling water formulations because of its excellent dispersion characteristics under high temperature conditions. (It is widely used in boiler feed-water formulations for the same reason.)... [Pg.159]

In Table 16.2 some of the typical characteristics of the various types of membranes and configurations are given. In MBR systems SW membrane modules are not used as the channels within the spiral are prone to clogging when the feed water has high suspended-solids concentrations. Tubular membrane systems are not common either as they tend to become very expensive due to the low area to volume ratio. Commercial MBR systems today are normally based on immersed FS configurations or H F/CT configurations. [Pg.370]

Fouling and scaling mechanisms are similar for spiral-wound NF and RO membranes. In general, NF feed water should meet the following characteristics to prevent fouling with suspended solids (refer to Table 7.1 for a more detailed description of spiral-wound RO feed water requirements) ... [Pg.344]

However, the usual tests for characterizing active carbon — such as the phenol number, the surface area (BET 2)> tl tannin index or the iodine index — are inadequate for evaluating the potential removal of the humic substances by the carbon. Moreover the resulting adsorption may differ according to the source and previous treatment of those substances and the characteristics of the feed water used. [Pg.403]

Once the pretreatment study had been completed, it will be possible to decide on the type of elements to be used in the reverse osmosis unit. If the SDI of the pretreated feed is 3.0 or less, then either the spiral wound or hollow fine fiber elements can be used. The choice will depend on economics (element price) and desalination characteristics (flux and rejection). If the pretreated feed SDI is more than 3.0, then the spiral wound element should be used. When the decision as to element type is made, then it is appropriate to forward a copy of the pretreated feed water analysis to reverse osmosis element manufacturers to obtain a prediction of product water quality, recommended type of element, total number of elements required, possible problems with sparingly soluble compounds in the feedwater, allowable recovery, and price and delivery. [Pg.286]

Characteristics of this membrane include 30 to 40% sodium chloride rejection, 85 to 90% magnesium sulfate rejection, 98% sucrose rejection, and 99% raffinose rejection. Water flux is 15 to 25 gfd at 35 to 50 psi, depending on feed-water composition. The effect of increasing salinity on salt rejection and water flux is similar to the behavior observed for NF-40 membrane as was illustrated in Figures 5.8 and 5.9. [Pg.332]

While most marked with the Ca(HCO )L, solution, it is significant that scaling occurs at all in such an evaporator system, where the total time of residence may be measured in milliseconds even if the residence time in the preheater is included, the feed water is in the apparatus for less than 10 seconds. It would appear that scale deposition from sea water is a function of local conditions of evaporation in a given apparatus and that reported delays in crystallization (I) are specific to the apparatus rather than to physical characteristic of scaling solutions. [Pg.68]

While size reduction or blockage of pores may be considered to increase the resistance of the membrane (Rm) to permeate flux, accumulation of materials in the cake and concentration-polarization layers (so-called polarised solids) presents additional resistances to permeation (denoted here as R c and Rep respectively). These resistances var) as a function of the composition and thickness of each layer, which in turn are determined by the feed water quality and the characteristics of mass transfer in the membrane module. In most instances encountered in water and wastewater treatment, it appears that the concentration-polarisation layer, if it is formed, contributes negligible resistance to permeate flux i.e. Rep << Rc and, therefore. Rep may be neglected (Mallevialle et al (1996)). While this is in reality not always the case (as shown in later sections of this chapter and in Chapter 7) for the filtration of... [Pg.178]

Within the overall system, every monoblock is assigned its own speciflc position and function. For each of the models described, the installations differ with regard to the number of monoblocks employed, their specific functions, dimensions, weight and energy capacity. These differences notwithstanding, the models may actually have the same steam output and use feed water of the same characteristics. [Pg.180]

Figure 2.27 Membrane flux characteristics of a spiral wound RO module for various feed waters. Source Film-Tec membrane catalogue. For non-pure water solutions the flux reaches a constant, steady state value at higher pressures. For optimal performance, the system should be run below the "critical flux" region, which is the mid-point of the curved part of the curve. Figure 2.27 Membrane flux characteristics of a spiral wound RO module for various feed waters. Source Film-Tec membrane catalogue. For non-pure water solutions the flux reaches a constant, steady state value at higher pressures. For optimal performance, the system should be run below the "critical flux" region, which is the mid-point of the curved part of the curve.
Trouble-free generation of steam requires water of high quality. The characteristics of boiler feed water and methods for its production are covered below in Section 12.4.3.3. This water is fed to the boiler(s) on demand. The simplest way to control the addition of water is from a level instrument in the steam drum. This iqrproach has a certain amount of inherent instability. When (cold) water is added to the drum in response to a demand from the level controller, some of the bubbles present in the liquid will collapse. Hie level will go down, and the controller will call for even more water. In the opposite case, when the level rises and the water flow is reduced, more bubbles will form and the level will increase, causing the controller to call for less water. The process itself is supplying positive feedback. [Pg.1172]

Design and neutronic characteristics of the reactor core ensure negative power, temperature, and void reactivity coefficients. As a result, self-limitation of the reactor power at the reactivity accidents and transients without scram takes place. Reactor self-control properties enable to change reactor power in the range of 20 - 100% of rated power (No) at a rate up to 0.5%No/s without control rods displacement and just for automatic control of feed water flow rate. [Pg.70]

The SulFerox sulfur-cake matrix tends to be quite compressible and reportedly lends itself well to filtration via plate-and-fiame filters or automated batch filter presses with recessed membranes for post-filtration sulfur-cake squeezing. It is claimed that only small amounts of wash water are needed to displace the residual process solution from the filtercake. Rotary drum vacuum filters were used in all early SulFerox applications, but variations in feed slurry characteristics due to differing inlet gas contaminants and required additive levels made their performance inconsistent. It is repotted that filtration by pressurized-feed filter presses has eliminated the problem of cake quality variation and has substantially reduced iron chelate losses (Anon., 1994). The sulfur filtercake from pressurized-feed filter presses is reported to contain 10 to 23 wt% moisture (Allen, 1995). [Pg.831]


See other pages where Feed water characteristics is mentioned: [Pg.36]    [Pg.6]    [Pg.996]    [Pg.319]    [Pg.36]    [Pg.6]    [Pg.996]    [Pg.319]    [Pg.80]    [Pg.207]    [Pg.207]    [Pg.435]    [Pg.224]    [Pg.446]    [Pg.372]    [Pg.1012]    [Pg.336]    [Pg.276]    [Pg.748]    [Pg.286]    [Pg.4492]    [Pg.160]    [Pg.375]    [Pg.85]    [Pg.134]    [Pg.228]   
See also in sourсe #XX -- [ Pg.150 ]




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