Page 317 - Fundamentals of Water Treatment Unit Processes : Physical, Chemical, and Biological

272 Fundamentals of Water Treatment Unit Processes: Physical, Chemical, and Biological

TABLE 10.10
Jet-Mix Installations
Flow Power=Unit Total Power Power=Unit of Flow
No.
Plant Place State (mgd) (mL=day) Units (hp) (kw) (hp) (kw) (hp=mgd) (kw=mL day)
Royer Nesbit Cucamonga CA 4.5 17 1 1 1 1 1 0.22 0.04
Waterman Fairfield CA 15 57 1 3 2 3 2 0.20 0.04
Southeast Salt Lake City UT 20 76 1 3 2 3 2 0.15 0.03
UTE Grand Junction CO 35 132 1 3 2 3 2 0.09 0.02
Wemlinger Aurora CO 40 151 1 5 4 5 4 0.13 0.02
Otay San Diego CA 40 151 1 5 4 5 4 0.13 0.02
Bollman Contra Costa CA 80 303 1 10 7 10 7 0.13 0.02
Anstay Hill Adelaide Aus. 85 322 1 10 7 10 7 0.12 0.02
Santa Teresa Santa Clara CA 100 379 2 8 6 15 11 0.15 0.03
Val Vista Phoenix AZ 140 530 1 15 11 15 11 0.11 0.02
Jordan Valley Salt Lake City UT 190 719 1 30 22 30 22 0.16 0.03
Henry Mills MWD-S.Ca. CA 330 1249 3 50 37 150 112 0.45 0.09
Average 0.17 0.03

Source: Adapted from Kawamura, S., Aqua—J. Int. Water Assoc., 49(6), 309, 2000.
Note: For installations where the number of units exceeds one, the assumption is that the flow is separated into the number of streams that equal
the number of jet-mixing units.

10.4.3.1.2 Nozzles
TABLE 10.11
A variety of nozzles are available for a wide range of indus-
Components in Design of Jet-Mixing System trial purposes (see, for example, Catalog 70 from Spraying
Design Component Systems Co., 2010), which may serve in a jet-mixing system.
Numerous ‘‘full-jet’’ types with different capacities are avail-
Raw-Water Coagulant
Pipeline Jet Pipeline Nozzles Feed able with conical spray cone angles, 0 u 1208. Another
type suitable for jet mixing has a flat spray pattern with angles
Diameter Metering Number Point of feed
of coverage, 0 u 1208 (Spraying Systems Co. VeeJett
pump
nozzles, catalog 70, pp. C3–C11). The nozzles are available
Flow Flow and head Flow and head Orientation
in different materials including stainless steel and may be
of flow
screwed into a manifold. Flow vs. pressure data are given
Flow variation Total flow Flow—each Feed velocity
for each nozzle. Data from one of the nozzles, i.e., H-15,
Velocity of water Diameter Diameter Flow
capacity size #15280, (158 angle and 28.0 gpm at 40 psi
Pressure at jet Appurtenances Velocity of core Pump selection
reference pressure), with orifice diameter given as ‘‘0.391’’
Valves- Orientation
were plotted and are shown in Figure 10.22, with scales in
actuated
Valves-control Upstream or both SI and U.S. customary units (see Spraying Systems Co.
downstream Catalog 70, p. B27 for nozzle shape and pp. B28–29 for data).
Flow meter Radial from The same data were used in the spreadsheet, Table CD10.12.
peripheral The ‘‘nominal’’ operating range shown is intended to show the
Pressure gage Radial from center expected limits of operation. The data, plotted on log–log
Spray angle scales, show a straight-line relationship giving the coeffi-
Diffusion plate cients, C(SI) ¼ 0.927 (C(US) ¼ 0.943) and n(SI) ¼ 0.510
(or not) (n(US) ¼ 0.505); flow may be calculated from the standard
orifice equation, i.e.,

specific aspects of design, with most seen in Figure 10.21. The p ffiffiffiffiffi n
Q ¼ CA( jet) 2gh (10:42)
items in each category indicate decisions and calculations that
should be considered in jet-mixer design. Example 10.9 pro-
vides an algorithm for incorporating most of the considerations where
listed in Table 10.11. The location of the alum feed is one of the C is the discharge coefficient (dimensionless)
2
considerations that could be perplexing. The alum feed point A(jet) is the area of orifice or nozzle (m )
seen in Figure 10.21 is logical in that the neat alum is mixed with n is the exponent (dimensionless)
the jet flow just prior to its dispersion into the raw-water flow. h is the head of water applied to orifice (m)