تصميم محطات مياة الشرب تحلية المياة RO plant
معادلات تصميم محطات المياة
تعرفنا فى عده مقالات متلاحقة عن كيفية تصميم محطات مياه التحلية بنظام التناضح العكسى ro واليوم نكمل هذه السلسة بشرح تصميم محطات مياة الشرب مع مثال عن تصميم محطة مياه شرب 100م/يوم وسنتعرف فى هذا المقال على
- تحديد كمية تدفق المياة بوحدات التناضح العكسى لأنتاج 100 متر
- قطر مواسير التوصيل
- حسابات حجم الفلتر الرملى
- حسابات حجم الفلتر القطنى
- حسابات عدد الممبرين والفيزل لوحده 100 متر
- حسابات اختيار مضخة التحضير الفلاشينج
- حسابات اختيار مضخة الغسيل الكيميائى
- الحسابات الكهربائية للمحطة
- حسابات حجم خزان الغسيل
- حسابات حجم خزان مياه التغذية
- حسابات كمية مياه الغسيل العكسى
- حسابات كمية المياة المرفوضة لوحده ro
- Examples from desing calculation to ro plant
Assume feed water TDS = 40000 ppm, so Osmotic pressure =30
:Selection for F.F.P
% (For sea water recovery (20:40
%so select 30
Recovery = Qp/Qf 0.3= 1000m3/d/ Qf Qf = 3000 m3/d
Q = A*V From curve η = 75% P = pghQ/ η
P= 1000*9.8*50*0.0347/0.75=22.68 kw
. Assume Head = 50 m
so we already make selection for F.F.P by deter P ,Q
(Head > ^P (S.F.)+ ^ P (C.F.) + Suction P of H.P.P. + losses + P (Sand filter
selection for pipeline
Assume water velocity V = 2 m/sec
Q = A*V , 0.0347 = 3.14/4*D²*2
D = 0.148 m D = 6 inch
Selection for Sand filter
Assume No. of S.F.= 2
V = 0.2 m/sec Q = 0.0347/2 =0.0174 m3/sec Q = A*V, 0.0174= D²/4 *# * 0.2/60 D = 2.5
selection for cartridge filatr
Flow per cart. 10″ =5 GPM= 5/4.4033 = 1.13 m3/h
Assume no. of C.F. = 2 filter Q1 = 125/2 = 62.5 m3/h=70m3/h
Q1 = no. of cartridge * qc, no. of cart. = 70/1.13 = 61.6 for cart.10
For 40 ” no. of cart. = 14 cart
-:Selection for R.O. membrane
Membrane product = 8 m3/ d No. of membranes = 1000/8 = 125 membrane No. of vessels = 125/6 = 20.8 =21 vessel + 3 vessel standby
Selection for flushing pump
Assume vessel need 8 m3/ h
Q = 8*24=192 m3/ hr
Selection for cleaning pump
Assume each vessel need 5.5 m3/h
Q = 5.5*24 = 132 m3/ hr
At case 500m3/ d -2
Q =A*V 70/3= D²*3.14*V/4
V = 23.3*4/3.14*2.8*2.8=3.78 m/ hr
At case 2x 500m3/ d Q =A*V , 140/3= D²*3.14*V/4 V = 4.6.6*4/3.14*2.8*2.8=7.5 m/ hr
Filtration rate between (10 :25 ) m3/m2.hr
Back Washe rate (20 : 40 ) m3/m2.hr
Air filtration rate (40 : 60 ) m3/m2.hr
Q=A*V = 240m3/hr
Retention time = Raw water tank volume /HPP (Q )m3/hr
To obtain the power for Pelton wheel
P1 (pelton) = Q*inlet P* 10.2 /367
(Consumed power = pump power (without pelton) – P1 (pelton
? How to calculate cleaning tank volume
No. of vessels to be cleaned = 8 vessel Volume of each vessel = 200 liter Empty so Min.
required tank volume = 2*200 =1600 lit
– The first 20 % of water is drained = 0.20*1600/10 = 320 liter
– The total capacity = 1600+320 =~2 m3 So for tank retention time with respect to pump 5*60/44 = 6.82 min
?How to calculate Raw water tank volume
2×146+2×70+10=442 m3/h Assume retention time = 1.5 hr , tank volume = 1.5×442 =663 m3 ~740 m3
How to calculate Backwash water tank volume
for 500 m/d unit
backwash rate = 25-35 m3/m2.h
Required water for back wash = 3.14*(2.8/2)*30 = 184.7m3/h
The time required for backwash = 15 min So the max.daily water required for backwash (3 filters) =184.7*15*3/60=138.5m3
For 1000 m3/d unit
backwash rate = 25-35 m3/m2.h
Required water for back wash = 3.14*(2.8/2)*30 = 184.7m3/h The time required for backwash = 15 min – So the max.daily water required for backwash(5 filters ) =184.7*15*5/60=230.8m3 Backwash tank volume = 231+138=369~400 m3
How to calculate Brine( reject) water tank volume
Reject water = brine water + Backwash water = (92.5*2 + 49*2) + (185) = 476 m3/h Retention time = 15 min Tank volume = 476/60*18=150m3
How to calculate flushing water tank volume
Say 5 min. for RO (500) &(1000) , 64*15/2/60+128*15*2/60=12+22+91(constant)=150m3
by eng/Ahmed Mahmoud
Operation Manager for sea water desalination plant 80000m3/d
شركة ماتيتو لمعالجة المياه
يمكنكم متابعته عبر يوتيوب https://youtu.be/BcIoNpJ0bhA
جزاه الله خيرا
التعليقات مغلقة.