Water Spray Design Calculation for Vertical Vessel Cylindrical Flat or Conical Top
N Number of ring
L Must not exceed 12' or 3.7 m as per NFPA 15
Data
h 0.5 m
D 4.8 m
H 4.06 m
Distance from tear seam to first ring
1 m 1 Number of Ring
L 3.7 m
N 1
2 Design area of the top (At)
At 18.87 m2
3 Total water required for the top (Qt)
Water densities for top 0.25 gpm/ft2 0.61 m3/hr/m2
Qt 11.55 m3/hr
4 Design area for the shell rings (As)
As 55.8 m2
5 Water required for the shell rings (Qs)
Water densities for shell 0.25 gpm/ft2 0.61 m3/hr/m2
Qs1 34.13 m3/hr
6 Design area for the bottom (Ab)
Ab 18.09 m2
7 Water demand for bottom (Qb)
Water densities for bottom 0.25 gpm/ft2 0.61 m3/hr/m2 each ring. For tanks with appendages or obstruction, design area may differ.
Qb 11.07 m3/hr 8 Water required for appendages (Qa)
Aa 0 m2
Water densities for appendages 0.25 gpm/ft2 0.61 m3/hr/m2
Qa 0 m3/hr
9 Design area of legs or support (Al)
w 0 m
h 0 m
l 0 m
Al 0 m2
10 Water required for each leg (Ql)
Water densities of leg or support 0.25 gpm/ft2 0.61 m3/hr/m2
Ql 0 m3/hr
11 Total water required (Qtot)
Qtot 56.75 m3/hr
Top Ring 1 Bottom Leg
12 Probable nozzle pressure (bar)
3.5 3.5 3.5 -
13 Distance nozzle to nozzle (m) 2.1 1.2 1.95
Distance from nozzle to tank (m)
0.2 0.6 0.6
Tank diameter (m) 4.8 4.8 4.8
Nozzle quantity (unit) 8 16 10
Capacity each nozzle (m3/hr) 1.44 2.13 1.11
Capacity each nozzle (L/min) 24 36 18
Nozzle angle used 120 160 180
Coverage 1.36 3 4
Status Not oke Ok Ok
14 Orifice size 16
Capacity each nozzle (L/min) 26.41 36
K-factor 10.0 17.3
Pressure (bar) 7 4.2
Coverage (m) 0.68
1.2 m
0.6 m
3 m
Water Spray Design Calculation for Vertical Vessel Cylindrical Flat or Conical Top
Must not exceed 12' or 3.7 m as per NFPA 15
Note
Trial and error
see graphic. It is a function of axial distance and spray angle To check the overlap. Ovelap shall be not to big
See graphic See graphic See graphic
As per NFPA 15 9-3.3 operating pressure at the hydraulically most remote nozzle shall be not less than 50 psi (3.5 bar). Static pressure maintained on the system prior to system actuation shall be maintained at a pressure no less than 50 psi (3.5 bar)
For outdoor application, the surface of the nozzle should be located no more than 2 ft (0.6 m) from the surface of tank
Conversion 0.0254 m
20 30 40
20% 24 36 48
30% 26 39 52
40% 28 42 56
50% 30 45 60
60% 32 48 64
70% 34 51 68
80% 36 54 72
90% 38 57 76
100% 40 60 80
0.51 0.76 1.02
20% 0.61 0.91 1.22
30% 0.66 0.99 1.32
40% 0.71 1.07 1.42
50% 0.76 1.14 1.52
60% 0.81 1.22 1.63
70% 0.86 1.30 1.73
80% 0.91 1.37 1.83
90% 0.97 1.45 1.93
100% 1.02 1.52 2.03
Tounge type nozzle - shell
Distance from nozzle to nozzle 1.2 m 0.6
Distance from nozzle to tank 0.6 m
Tank diameter 4.8 m
Nozzle quantity 16 unit
3 Capacity each nozzle 2.13 m3/hr
36 L/min
Nozzle angle 160
Pressure
Coverage 3.00 m
oke
Orifice size No 16
K-factor 17.3
Pressure 4.2 bar
60 72 78 84 90 96 102 108 114 120 1.52 1.83 1.98 2.13 2.29 2.44 2.59 2.74 2.90 3.05
1.2 m
m
m