Utilities in a Process House

Electrical

UNITS FORMULA

1 KVA

0.7 X AMP

1 KVA

1.1 X KW

1 AMP

1.67 X KW

1 AMP

1.4 X KVA

1 KW

0.6 X AMP

1 KW

0.9 X KVA

1 KW

0.73 X HP

1 HP

1.37 X KW

 

POWER CABLES

NYY

N – Copper Conductor

 

Y – PVC Insulation

 

Y – PVC Oversheath

NYRGbY

RGb – Round Steel Wire Armoured

NYFGbY

FGb – Flat Steel Wire Armoured

NYA

A – Sloid Copper Conductors

NYAF

AF – Flexible Copper Conductors

NYM

M – House Installations

BCC

Bare Copper Conductors

  

 

CABLES CURRENT CAPACITY

SIZE in Sq MM

CURRENT

OUTER DIA

4C X 1.5

18 A

12.5

4C X 2.5

25 A

14

4C X 4

34 A

15.5

4C X 6

44 A

17

4C X 10

60 A

18.5

4C X 16

80 A

23

4C X 25

105 A

27

4C X 35

130 A

29.5

4C X 50

160 A

30.5

4C X 70

200 A

34

4C X 95

245 A

39

4C X 120

285 A

42

4C X 150

325 A

47

4C X 185

370 A

51.5

4C X 240

435 A

58.5

4C X 300

460 A

65

PT100 SENSORS

After 100 Ohms, 1Ohm = 2.6 deg C, 200 Ohms = 260 deg C

1 deg C = 100 ++0.385 Ohm

2 deg = 100 + 0.77 Ohm

Resistance at T temp deg C = 100 + (T*0.385) Ohms

Steam

STEAM

 

Pressure

Temp

Total Heat

Steam Pipe Capacity in Kg/Hr  (Velocity- 25 m/Sec)

 

 Kg/Cm2

Deg C

Kcal/Kg

1/2″

1″

11/2″

2″

3″

4″

1

99

639

12

48

100

193

445

730

2

120

646

19

70

162

295

656

1215

3

133

651

26

100

225

425

910

1580

4

143

654

30

115

270

450

1080

1980

5

151

656

36

135

308

548

1265

2110

6

158

658

43

162

370

658

1520

2530

7

164

660

49

190

450

785

1750

3025

8

170

661

54

205

465

810

1870

3240

9

175

662

60

228

514

900

2038

3533

10

179

663

66

257

562

990

2205

3825

12

187

665

75

300

651

1183

2663

4513

14

  

85

331

740

1375

3120

5200

Deg C to Deg F Conversion                                                                

Deg F = 1.8 X DegC + 32                                                                                                                                                                                            

Deg C = (deg F -32) / 1.8                                                                                                                                                                                           

Average Fuel Requirement is 65 lts / Ton of Steam                                                                                                                                                                                                         

Steam Wastage                                                                                    

3 mm hole at a Pr. Of 6 Kg / cm2 will waste 18 Kgs of steam / hour                                                                                                                                                      

Calorific Value                                                                                     

Heavy Oil   9766 Kcal / ltr                                                                                                                                                                                            

IDO   9270 Kcal / ltr                                                                                                                                                                     

Solar  9063 Kcal / ltr                                                                                                                                                                                                    

Total Heat to be Removed / added from any Substance  in Kcal =                                                                                                                                                       

    Specific Heat of Substance X Weight in Kgs X  t             

        t = t2 – t1                                                                                                              

For water, as Sp. Wt is 1, Kcal =   Weight  X    t X 1 Kcal

Pipe Size Calculation

STEAM PIPE SIZE CALCULATION

 

Dia of Pipe required ( mts) =

    

1.15 X Sq rt {( Flow rate Kg/hr X Sp. Volume m3/Kg) / (Velocity m/sec X 3600)}

 
       

FLOW

PRESSURE

SP.VOLUME

VELOCITY

REQUIRED

REQUIRED

 

Kg/hr

Kg/cm2

m3/Kg

m/sec

PIPE DIA mts

PIPE DIA Inch

 

2925

1

1.725

25

0.268

10.53

 

2925

2

0.902

25

0.193

7.62

 

2925

3

0.617

25

0.160

6.30

 

2925

4

0.471

25

0.140

5.50

 

2925

5

0.382

25

0.126

4.96

 

2925

6

0.321

25

0.115

4.54

 

2925

7

0.278

25

0.107

4.23

 

2925

8

0.245

25

0.101

3.97

 

2925

9

0.219

25

0.095

3.75

 

2925

10

0.198

25

0.091

3.57

 

Note: Specific Volume is taken from Steam Tables for that particular Pressure

 

WATER PIPE SIZE CALCULATION

 

Dia of Pipe required (mts) =

    

Sq. Rt {(Flow Rate in m3/hr X 4 / (3.14 X Velocity in m/sec X 3600)}

 

FLOW

Velocity

REQUIRED

REQUIRED

   

m3/hr

m/sec

PIPE DIA mts

PIPE DIA Inch

   

200

2

0.188

7.41

   
       

Flow Rate in m3/hr =

     

SQ{Pipe Dia in mtr X Sq. Rt (3.14 X Velocity in m/sec X 3600)/4)}

 

PIPE DIA

PIPE DIA

VELOCITY

 

FLOW

  

inches

mtr

m/sec

 

m3/hr

  

2

0.0508

1.5

3.31

10.94

  

Note:

      

Velocity, if there is gravity flow = 1 m/sec

   

Velocity, if there is pump discharge flow = 2 m/sec

   

Velocity, if there is pump suction flow = 1.5 m/sec

   

COMPRESSED AIR PIPE SIZE CALCULATION

 

Dia of Pipe required (mts) =

    

Sq. Rt {(Flow Rate in m3/hr X 4 / (3.14 X Velocity in m/sec X 3600)}

 

Flow rate in m3/hr = (FAD in CFM / 35.31) X 60) / Compression Ratio

 

Compression Ratio = (Gauge Pressure + Atmosp. Pressure)/ Atmosp. Pressure

       

FAD

GAUGE PR

COMPRES.

FLOW

Velocity

REQUIRED

REQUIRED

CFM

Kg/cm2

RATIO

m3/hr

m/sec

PIPE DIA mts

PIPE DIA Inch

53

7

7.91

11.39

6

0.026

1.02

       

Note:

      

Velocity of Compressed Air (average- for calculation) = 6 m/sec

  

Thermal Oil Heaters

 

EFFICIENCY                                                                                                                                      

Efficiency    =    100 –  Losses                                                                                                                                                                                                                             

Losses                                                                                                                                                                                                                                                         

Stack Loss  (%) =          0.56   ( Stack Temperature C  – Ambient Temperature C )

                                                                                                                              CO 2 %                                                                                                                            

Loss Due to Radiation & Conduction =  1  to 2 %    ( Difficult to calculate)

H2 & Moisture Loss   =  Applicable if calculated based on GCV and not when

                                                based on  NCV and hence not required                                                                                                                                                                                                                                                              

Efficiency    =  100  –  (Stack Loss in %  +  2 %)                                                                                                                                                                                                                                                                          

 

OUTPUT ASSESSMENT                                                                                                                                  

Total Thermal Output = Thermal Oil Flow Rate  X  Sp. Gravity of Oil at that Temp.  X

                                              Sp. Heat of Thermal Oil  X  ( t2 – t1)

If Thermal Oil Heater Out put capacity is 2 million Kcal, and Oil Flow rate is 120 m3 / hr

Then, 2 mil Kcal/ hr =  120,000 X 0.7 X 0.7 X (t2-t1)                                                                                                                                                                                                                                                                     

And so, t2-t1 (delta t )  =             2,000,000              =   34 deg C                                                                                                                                  

                                              120,000 X 0.7 X 0.7

Air Compressor Details

Most air compressors deliver 4 to 5 cfm per hp at 100 psig discharge pressure. 

• Every 10 degrees Fahrenheit change in inlet air temperature affects the efficiency about 1%. Colder temperature increases and warmer temperature decreases efficiency. 

• Power cost for 1 hp for 3 shifts, 7 days a week (8,760 hours) at 10 cents/kWh = about $750/year. 

• A 50 hp compressor rejects approximately 126,000 Btu per hour. Approximately 119,000 Btu/hr of this is recoverable. 

• Size control air receiver located after compressor for about 1 gallon capacity per cfm of compressor capacity. 

• Size storage air receiver for about 2-4 gallon capacity per cfm of compressor capacity. This results in an effective demand side control management system. 

• Total pressure drop across all compressed air system components, including piping, should not exceed 15 psi.

Waste Water Treatment – Biological

A biological wastewater treatment plant’s goal is to provide an optimum environment for the microbial population. The primary environmental factors include:

Dissolved Oxygen (DO): Critical to the maintenance of efficient aerobic conditions a minimum DO of 2 mg/L is recommended in all areas of an aeration basin or treatment process.

Nutrients: Macro nutrients nitrogen and phosphorus must be present in sufficient quantities to support biological growth. The recommended BOD:N:P ratio of 100:5: 1 (based on influent loadings) is the minimum to support good treatment.

pH: Influent to the biological treatment should be maintained at a pH of 6.8-8.2 at all times during the treatment process. Nitrification is optimized at a pH of 7.6-8.2 and should be closely monitored.

Temperature: Biological growth occurs at operating temperatures of 45°F [7.2°C] to 140°F [60°C] with optimum growth rate at 70°F [21.1°C] to 90°F [32.2°C].