Design calculation sheet and type selection of 200 m3 / h ro + mixed bed process

1) Raw water pool

The design residence time of raw water tank shall not be less than 1 hour, and the effective volume shall not be less than 300m3

2) Raw water pump

The raw water pump shall meet the two process conditions of five media filters running at the same time and four filters running and the other filter washing. When five filters are running at the same time, the inflow flow is 270t / h, when four filters are running and the other filter washing, the inflow flow is 350t / H.

The raw water pump has a flow rate of 270-350t / h, a head of 38-36m and a power of 55kW. Two pumps, one for use and one for standby, are selected in the system.

3) Steam water mixing heater

One steam water mixing heater is selected in the system, and the heating water volume is 270-350t / h.

The specification of heat exchanger is φ 425, the specification of water inlet and outlet is DN300, and the specification of steam inlet is dn400.

a. Steam consumption:

Basic conditions: steam property is superheated steam, the maximum water temperature difference between inlet and outlet is 25 ℃, steam temperature: 170 ℃, steam pressure not more than 0.8MPa, steam enthalpy: 2726.5kj/kg, steam specific volume: 0.2403m3/kg, water specific heat: 4.18kj/kg. ℃.

350t / h water heating at 25 ℃, heat exchange required: q = 350 × one hundred and three × four point one eight × 25=3.65 × 107KJ/h

Amount of heating steam required: g = q ÷ two thousand seven hundred and twenty-six ÷ 1000=10.35t/h

The steam loss coefficient along the way is 10%, and the actual gas demand is 13.4t/h.

Steam volume required per hour: 13.4t/h × 0.2403m3/Kg × 1000=3224m3/h

b. Selection of steam pipeline:

The flow rate of steam pipe is 62-73m / s, and the main steam inlet pipe shall be: φ one hundred and thirty-three × 4。

4) PAC dosing device

The design dosage of coagulant dosing device for purified river water is 3ppm, the operation water inflow of the front system is 270t / h, and the water inflow is 350t / h when a filter is washing.

The dosage of PAC during operation is 270t / h × 3PPm ÷ 1000=0.81kg/h。

When a filter is washing, PAC dosage is 350t / h × 3PPm ÷ 1000=1.05kg/h。

When the concentration of the prepared reagent is 10%, the actual dosing amount of the metering pump is 8.1l/h in operation, and the dosing amount is 10.5l/h when a filter is washing.

Two pumps and one box type dosing device and one metering pump for use and one for standby are selected.

The mixing tank is prepared once every 48 hours, one liquid medicine mixing tank with effective volume of 0.4m3, equipped with metering pump c726, flow rate: 15.1l/h, head: 6.9bar, motor power: 44w, the dosing pump adopts automatic dosing, and the dosing amount is automatically adjusted according to the inflow flow signal.

5) Bactericide dosing device

Sodium hypochlorite is used in the bactericide dosing device. The designed effective chlorine dosing amount of the dosing device is 1ppm. The water inflow of the front system is 270t / h. When a filter is washing, the water inflow is 350t / h.

During operation, the dosage of sodium hypochlorite is 270t / h × 1PPm ÷ 1000 = 0.27kg/h (available chlorine).

When a filter is washing, the dosage of sodium hypochlorite is 350t / h × 1PPm ÷ 1000 = 0.35kg/h (available chlorine).

The effective chlorine concentration is 4%, the actual dosing amount of the metering pump is 6.75l/h in operation, and the actual dosing amount of the metering pump is 8.75l/h when a filter is washing.

The matching mixing tank is prepared once every 48 hours, one liquid medicine mixing tank with an effective volume of 0.4m3, two metering pumps b126, flow rate: 9.5l/h, head: 6.9bar, motor power: 29w.

6) Tubular mixer

The design flow rate of tubular mixer is 270-400t / h, and the design flow rate is 1.0-1.5m/s.

The mixer is selected as φ three hundred and twenty-five × The number of mixing sections of the mixer is three.

7) Multi media filter

Design flow rate: 8-10m / h, selected specification: 1 φ 3024, single unit design water yield: 56-70t / h.

Five sets of multi-media filters are prepared in the system and operated at the same time for backwashing respectively.

A. calculation of operation cycle of multi-media filter:

Sewage interception capacity: 0.75kg/m3 filter material (filling height of single filter material: 1200mm, volume of single filter material: 8.4m3)

5 mg / L for influent and 0.5 mg / L for effluent.

Filtration cycle of single filter: 1000 × 0.75Kg/m3 × 8.4m3 ÷( 5mg/L-0.5mg/L) ÷ 56t / h = 25 hours.

B. calculation of forward washing water consumption of multi-media filter (the forward washing water uses the former stage water)

The washing intensity of single filter is 70t / h (the washing flow rate is 10m / h), and the washing time is 10min

Water consumption of primary washing of filter: 70 × ten ÷ 60 = 11.66 tons

The water consumption rate of the filter is 11.6 tons ÷( twenty-five × 56)=0.8%

C. calculation of backwashing water consumption of multi-media filter (concentrated water for backwashing water)

The washing intensity of single filter is 302t / h (the backwashing flow rate is 43.2m/h), and the backwashing time is 10min

Primary backwashing water consumption of filter: 302 × ten ÷ 60 = 50.3t (RO concentrated water for backwashing water)

D. compressed air consumption of multi-media filter gas backwashing:

The gas backwashing intensity of the multi-media filter is 20L / m2. S, the filter cross-sectional area is 7m2, and the backwashing gas volume is 7 × twenty × three point six ÷ 60=8.4m3/min。

8) Activated carbon filter

Design flow rate: 8-10m / h, selected specification: 1 φ 3024, single unit design water yield: 56-70t / h.

Five sets of activated carbon filters are prepared in the system and operated at the same time for backwashing respectively.

A calculation of forward washing water consumption of activated carbon filter

The forward washing intensity of single filter is 70t / h (the forward washing flow rate is 10m / h), the forward washing time is 10min, and the backwashing and forward washing are carried out every 48 hours.

Water consumption of primary washing of filter: 70 × ten ÷ 60 = 11.66 tons

The water consumption rate of the filter is 11.6 tons ÷( forty-eight × 56)=0.4%

B calculation of backwashing water consumption of activated carbon filter

The washing intensity of single filter is 202T / h (the backwashing flow rate is 28.8m/h), and the backwashing time is 10min

Primary backwashing water consumption of filter: 202 × ten ÷ 60 = 33.7t (RO concentrated water for backwashing water)

9) Thickener

The concentrated water tank shall meet the water consumption of single filter backwashing at one time.

Through the above calculation, the single multi-media filter backwash water consumption is 50.3 tons, activated carbon filter backwash water consumption is 33.7 tons.

Actual volume of concentration tank: 100m3

10) Filter backwash pump

The backwashing water pump shall meet the backwashing flow rate of single filter: kqw200 / 250-30 / 4, flow rate: 320t / h, head: 21m, motor power: 30.0kw, one backwashing water pump is set in the system.

11) Reverse osmosis inlet pipe mixer

The influent flow of RO is 270t / h, the design flow rate is 1-1.5m/h, and the mixer specification is as follows: Φ three hundred and twenty-five × one thousand and four hundred

12) Non oxidizing bactericide dosing device

The design dosage of non oxidizing bactericide for RO influent is 150ppm, and the influent quantity of RO is 270t / h.

The dosage of non oxidizing bactericide is 270t / h × 150PPm ÷ 1000=40.5kg/h。

The dosing device with one pump and one box is selected to sterilize the reverse osmosis system regularly.

According to the 5-day storage capacity of the dosing tank, there is a liquid medicine mixing tank with an effective volume of 0.2m3, equipped with gm0050 metering pump, flow rate: 50L / h, head: 10bar, motor power: 0.25kw.

13) Scale inhibitor dosing device

The maximum LSI of RO concentrated water side is 1.9. According to the calculation of American PWT calculation software, the dosage of scale inhibitor Titan ASD 200 is 3.5ppm, and the water inflow of RO is 270t / h.

The dosage of scale inhibitor is 270t / h × 3.5PPm ÷ 1000=0.945kg/h。

The concentration of the prepared reagent is 10%, and the actual dosage of the metering pump is 9.45l/h.

Two pumps and two boxes of dosing device and one metering pump for use and one for standby are selected.

The mixing tank is prepared once every 48 hours. There are 2 mixing tanks with effective volume of 0.5m3. It is equipped with metering pump c726 with flow rate of 17L / h, head of 6.9bar and motor power of 44w. The dosing amount of the metering pump is automatically added according to the reverse osmosis inflow flow.

14) Security filter

Two security filters are used in the system at the same time. The water yield of a single filter is 135t / h. The large flux filter element produced by Beijing Hezhong, a Sino British joint venture, is selected. The water yield of a single filter element is 45-70t / h. three large flux filter elements are selected for a single filter. The specification of the security filter is Φ 410, with 3 filter elements in it, with the specification of: φ one hundred and fifty point four × 1016.

15) High pressure pump

The reverse osmosis membrane components of hydergy company (or Dow company) are used. The water yield of single set of reverse osmosis is 100t / h, the working pressure is 1.11-1.31mpa, and the high-pressure pump model is pwt100-65-315s, q = 135t / h, H = 140m,

N=90KW。

Two sets are selected in the system and run at the same time.

16) Reverse osmosis unit

17) Reverse osmosis cleaning system

The membrane shell 80s-300-6b of a single set of reverse osmosis device is made of 18 pieces, arranged in 2:1. The reverse osmosis cleaning is carried out by stages and sections. The cleaning water pipe is DN 125, which is calculated according to the length of 30m.

a. Cleaning water pump:

The cleaning flow rate of single module shell is 8-12T / h, and the cleaning flow rate of one section is 144t / h

Cleaning water pump: kqwh125-160, flow: 150t / h, H = 33m, n = 22KW.

b. Liquid medicine filter:

The liquid medicine filter is: φ 410, with 5um large capacity filter element, the specification is: φ one hundred and fifty point four × 1016, a total of 3, single water yield: 45-70t / h.

c. Pipe cleaning:

The chemical cleaning pipeline adopts DN 125, and the design flow rate is 3.26m/s.

d. Selection of cleaning water tank:

Volume of single membrane shell: 0.1884m3, total volume of the first stage membrane shell of single reverse osmosis: V1 = 0.1884 × 12=2.26m3

Volume of liquid medicine filter: V2 = 0.15m3

Cleaning pipeline volume: V3 = 0.38m3

Total volume: v = V1 + V2 + V3 = 2.79m3

The required cleaning water tank is 1.2V = 3.34m3, and 5M3 cleaning water tank is actually selected

e. Electric heating system:

Heating water mass: M = 3340kg, raw water temperature: T2 = 25 ℃, cleaning solution temperature: T1 = 35 ℃, medium specific heat: C = 1kcal / kg ℃, thermal work equivalent: 860, heating time of each box of solution: T = 2 hours.

Heat exchange required for each tank: q = m (t2-t1) × C=33400kcal

The required power of electric heater: P = q / 860t = 19.4kw, the actual electric heater n = 20kW, a total of 1 set.

18) Ro flushing water pump

The cleaning flow rate of single module shell is 8-12T / h, and the cleaning flow rate of one section is 144t / h

Cleaning water pump: kqwh125-160, flow: 150t / h, H = 33m, n = 22KW.

19) Carbon remover

The carbon dioxide content in the effluent of reverse osmosis unit is about 20mg / L, and the water inflow of carbon remover is not less than 202T / h φ One set of 2200 carbon dioxide remover, the designed water yield of a single set is 202T / h, the designed drenching density is 50-60l / m2. H, and the designed effluent carbon dioxide content is 3mg / L.

When the design water temperature is 25 ℃, the water temperature is 25 ℃ φ The layer height of more than 50 hollow spheres: 2000mm.

20) Intermediate pool

The design residence time of the intermediate pool is 20min, and the actual selection of the intermediate pool is 75m3

The middle pool is of steel concrete structure.

21) intermediate water pump

The designed lifting capacity of the intermediate water pump is 202T / h, and two pumps are selected in the system, one for use and one for standby.

The specification of the middle water pump is kqwh150-315, the flow rate is 210t / h, the lift is 31m, and the motor power is 30kW

22) mixed ion exchanger

Basic conditions:

Salt content of RO effluent: 2.5ppm, equivalent to the salt content of RO effluent Σ A (total positive)= Σ K (total anion) = 0.032mg-n / L, the carbon dioxide content in the outlet water of the carbon remover is 3mg / L, equivalent to 0.068mg-n / L bicarbonate ion, and the total anion content in the actual mixed bed inlet water Σ K (total negative) = 0.1mg-n / L.

Diameter of mixed ion exchanger: φ There are two 2500 sets in total, one for use and one for standby. The design flow rate is 42m / h, and the water yield of single set is 202T / h.

Cation resin: 001 × 7MB

Loading height of cation resin: 500mm

Working exchange capacity of cation resin: 500mg-n / L.

Select anion resin: 201 × 7MB

Filling height of anion resin: 1000mm

Working exchange capacity of anion resin: 250mg-n / L.

Quantity of cation resin loaded in single unit: 2.45m3

Quantity of anion resin filled in single set: 4.9m3

Consumption of cation resin acid: 75kg (100% HCl) / M ³ Cation exchange resin

Alkali consumption of anion resin: 70kg (100% NaOH) / M ³ Anion resin

A. Mixed bed cycle:

T positive = t negative = 4.9 × two hundred and fifty ÷ zero point one ÷ 202 = 60 (hours)

B. acid base metering tank of mixed bed:

30% acid consumption for primary regeneration of cation resin in mixed bed

two point two five × seventy-five ÷ 30%=563Kg

Vr=750 ÷ 149 = 489 L (density of 30% hydrochloric acid is 1.149g/cm3)

C mixed bed acid metering tank: 1.2 × VR = 600 L

The actual mixed bed acid metering tank is 1100 liters

D. 30% alkali consumption for primary regeneration of anion resin in mixed bed:

four point nine × seventy ÷ 30%=1143Kg

Vr=1400 ÷ 1.37 = 834 L (30% lye density is 1.37 g / cm3)

E mixed bed alkali metering tank: 1.2 × VR = 1002 liters

The actual selection of mixed bed alkali metering tank is 1100 liters

Reclaimed water consumption of mixed bed

The reclaimed water consumption of mixed bed is calculated as 8 times of resin volume, and the one-time reclaimed water consumption of single bed is 59m3

Actual water consumption of mixed bed: 59 ÷ sixty ÷ 202 = 0.5% (1% in process)

Water production cycle of mixed bed: 60 hours

Water yield of mixed bed: 202T / h

23) desalination tank

The desalting tank is designed according to 3-hour storage capacity, with an effective volume of 600m3.

24) desalted water pump

Two sets of desalted water pumps are used in the system, one for use and one for standby, model: kqwh150-400, flow rate: 200t / h, H = 50m,

N=45KW。

25) calculation of flow rate of acid-base ejector

a. Outlet flow of mixed bed acid (alkali) ejector: QA = 4.9 × 5 = 22.5t/h (cross section area of mixed bed is 4.9m2, acid-base regeneration flow rate is 5m / h)

Hydrochloric acid concentration at ejector outlet: 2.5-5%

Alkali concentration at ejector outlet: 2-5%

Dilution water (pressure desalted water) flow Q = 22.5 ×( 1-5%) × 2=21.4t/h

Hnp2518 acid-base injector was selected.

26) regeneration pump

The regeneration pump shall meet the pressure water flow when the cation and anion resins of the mixed bed are regenerated at the same time.

Mixed bed regeneration flow Q = 21.4 × 2=42.8t/h

The pressure of regeneration pump shall be greater than 0.3MPa, and the regeneration pump shall be kqwh80-160, q = 50t / h, H = 32m, n = 7.5kW. Two sets, one for use and one for standby, shall be selected in the system.

27) acid storage tank

The acid storage tank shall meet the 15 day acid storage capacity of the system,

Two mixed ion exchangers are selected, one for use and one for standby, and the operation cycle is 60 hours (the operation cycle is about 2.5 days)

The consumption of 30% acid for each cycle regeneration of cation resin in mixed bed is 0.489m3

Acid consumption of the system in 15 days: 15 × zero point four eight nine ÷ 2.5=2.94m3

The actual acid storage tank: v = 10m3, which can meet 50 days of acid storage.

28) alkali storage tank

The alkali storage tank shall meet the 15 day alkali storage capacity of the system.

Two mixed ion exchangers are selected, one for use and one for standby, and the operation cycle is 60 hours (about 2.5 days)

1.02m3 of 30% lye is used for each cycle regeneration of anion resin in mixed bed

Alkali consumption of the system in 15 days: 15 × one point zero two ÷ 2.5=6.12m3

The actual selection of alkali storage tank v = 10m3 can meet the 24-day alkali storage.

29) acid unloading pump

The acid unloading capacity of the acid unloading pump is calculated by filling one storage tank in 0.75 hours

Acid unloading pump: 50fsb-20l, flow: 15t / h, lift: 20m, motor power: 3.0kw

30) alkali discharge pump

The acid unloading capacity of alkali unloading is calculated by filling the alkali storage tank in 0.75 hours

Alkali discharge pump: 50fsb-20l, flow: 15t / h, lift: 20m, motor power: 3.0kw

31) acid mist absorber

The acid mist absorber adopts alkali bubbling type, and one set is set in the system to absorb acid mist in acid metering tank and acid storage tank Φ five hundred × 800。

32) acid base neutralization tank

The drainage of the system is divided into acid-base wastewater and neutral wastewater. The neutral wastewater in the system mainly comes from the backwashing and washing drainage of the filter. The neutral wastewater is collected by the trench and discharged into the drainage pipe network of the plant. The acid-base wastewater is collected by the trench and discharged into the neutralization tank.

The capacity of acid-base neutralization tank is determined according to the discharge amount of acid-base wastewater from one-time regeneration of mixed bed. The discharge amount of acid-base wastewater from one-time regeneration of mixed bed is calculated as 8 times of resin volume. The resin loading amount of single mixed bed is 7.35m3, and the amount of acid-base wastewater from one-time regeneration is 59m3. The actual effective volume of neutralization tank is 90m3, the depth of neutralization tank is 3M, the effective water depth is 2m, and the area of neutralization tank is 45m2.

33) neutralization tank circulating pump

The circulating pump of neutralization tank is calculated by circulating acid and alkali waste liquid once every 1.5 hours. The circulating pump of neutralization tank is 80yw40-15-4, with flow rate of 48T / h, head of 13m, motor power of 4kw. Two sets are selected in the system, one for use and one for standby.

34) ammonia dosing system

The ammonia dosage of the desalted water is 1ppm, the water supply of the desalted water is 200t / h, the ammonia dosage is 0.2kg/h, the ammonia concentration is 1-5% (the dosing concentration is 1%), the metering pump is gm0025, the flow is 25L / h, the lift is 1.0MPa, and the motor power is 0.25kw. Two sets are used in the system, one for use and one for standby, and the frequency conversion dosing is adopted

Two ammonia dosing metering tanks are selected in the system, each with a volume of 0.5m3, according to the 24-hour drug storage capacity.

35) resin trap

There is one resin trapper on the outlet pipe of each mixed bed, with a filtration accuracy of 0.2mm, two sets in total

36) compressed air volume for process and capacity of air storage tank

a. Gas consumption of mixed bed:

The resin mixed gas consumption of the mixed bed is 2.5-3m3/m2.min, the cross-sectional area of the mixed bed is 4.9m2, the gas mixing time is 2min, the inlet pressure is reduced to 0.15Mpa, and the working pressure is 0.8MPa.

Gas consumption of resin mixing in single mixed bed: 3 × 4.9 = 14.7m3/min, 2min at a time, 0.15Mpa compressed air at a time, 29.4m3.

b. Gas consumption of multi-media filter:

The amount of compressed air for multi-media filter gas backwashing is 8.4m3/min, 5min at a time, and the amount of compressed air of 0.15Mpa at a time is 21m3.

C. Gas consumption of neutralization tank:

The gas stirring intensity is 5M3 / m2. H, and the neutralization tank area is 45m2

Gas consumption of neutralization tank: 45 × five ÷ 60 = 3.75m3/min (gas source pressure 0.15Mpa)

D selection of air storage tank:

Each gas equipment in the system is separated, the maximum instantaneous gas consumption of the system is 14.7m3/min, the compressed air volume of 0.15Mpa at a time is 29.4m3 (equivalent to 8.16m3 compressed air of 0.8MPa), the capacity of compressed air storage tank is required to meet the maximum instantaneous gas supply of the system: one set of air storage tank with 10m3 capacity is selected, and the design pressure is 0.8MPa.

F selection of air inlet pipeline:

The air inlet pipeline of air storage tank shall meet the air demand of neutralization tank gas mixing: 0.15Mpa compressed air 3.75m3/min is required for neutralization tank gas mixing, which is equivalent to 0.8MPa compressed air 1.04m3/min.

The specification of air inlet pipe of air storage tank is DN50, and the air supply of air storage tank needs to be reduced to 0.15Mpa.