To determine sat steam temp using calculator

You can determine sat steam temp quickly using calculator. Not the actual value but close enough. Try the following steps.

1.) Square root of pressure in bar (g)

2.) Square root the result of (1) above

3.) Result (2) x 100

The value you will get maybe +- a few degree C. Salesman will find it useful bcos a few C difference is better than don’t know. Scientist will say it is rubbish. Engineer has a dilemma bcos he cannot bull shit. Therefore he modifies the procedure a bit to make it works better with +- one degree C difference. Try the procedures in the attached pic. Good luck.

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Sizing calculations for BFW pumps and Fans for a typical Biomass fired Boiler

Sample sizing calculations for BFW pumps and Fans for a typical Biomass fired Boiler generating steam of 50,000 Kg/hr at 67 kg/cm2 and 485 degC. (110,000 lb/hr at 950 PSI & 905 F).

Feed Water inlet at 105 C and Exhaust gas temp at 200 C.first calculate heat load and fuel consumption of the boiler.

Pressure and temp at 1. Superheater Outlet : 67 Kg/cm2 & 485 C

2. Steam Drum : 73 Kg/cm2 & Saturated

3. Feed Pump inlet : Water inlet at 105 C

From Steam tables,

Enthalpy of Superheated steam , Hsh = 809 Kcal/ kg = 1456 BTU/lb

Enthalpy of Drum water , Hdwat = 305 Kcal/kg = 549 BTU/lb

Enthalpy of inlet water , Hwat = 105 Kcal/kg = 189 BTU/lb

Assume 3% Blowdown from Boiler.

Total Heat Load of the Boiler = Total heat absorbed by water to convert to steam + heat absorbed to get superheated + Blow down losses

= 50000(809-305) + 50000 x 1.03 x (305-105)

= 35.5e06 Kcal/hr = 140.87e06 BTU/hr

Fuel consumption = Heat Load/ (HHV x Efficiency)

= 35.5e06/ (7278 x 0.8649)

= 5639 Kg/hr = 12428 Lb/hr of coal

From previous article on Combustion and efficiency,

Wet gases = 14.05 and Air = 13.12 kg / kg of coal

Therefore, Exhaust gases produced = Fuel consumption x UnitWetGas

= 5639 x 14.05

= 79,228 Kg/hr of wet gases

Combustion Air required = 5639 x 13.12

= 73,984 Kg/hr of combustion air

Feed Water required = 50,000 x 1.03 : 3% Blowdown

= 51,00 Kg/hr

Sizing Calculations :

Boiler feed Water Pumps :

Two pumps of 100 % capacity are required one for working and one for standby.

Each pump discharge capacity minimum= 51500 Kg/hr

= 51500/950 : 950 kg/m3 water density

= 53.8 m3/hr

Margin on discharge capacity : 15- 25 %.

Take 20% margin in this case.

So discharge capacity of each pump : 53.8 x 1.2

= 64.6 m3/hr =say 65 m3/hr

If Recirculation valves are not provided, you need to add min recirculation flow to the above figure, which may be about 6-10 m3/hr depending up on pump type and make.

Pump head required = Drum Pressure + Drum elevation + Piping Losses + Control Valve Loss + Other valve losses

= 75 Kg/cm2 + 2.0 + 2.0 +5.0 +2.0

= 86 Kg/cm2

= 86 x 10/0.95 mts of water head at 105C

= 905 mts of WC

Provide up to 5% margin on head. So final Pump head is 905 x 1.05 = 950 m of WC

So BFW pumps (2 nos) rating is 65 m3/hr at 950 m of WC with feed water at 105 C.

b) Sizing calculations of FD Fan :

Forced Draft Fan is required to pump in primary combustion Air into the Boiler furnace. Air from FD fan passes through Air Heater before entering furnace through Grate. Secondary Air Fan (SA fan) supplies secondary combustion air in to the furnace. Usually primary air is 70 -80 % of the total air and balance is supplied as secondary air through SA fan. Secondary air is supplied at a higher pressure to help fuel spreading on the grate called as pneumatic spreading.

Total combustion Air, Kg/hr = 73,984

= 73994/(1.17 x 3600) m3/s :Air density-1.17kg/m3

= 17.56 m3/s

Primary Air , 70% of total , m3/s = 0.7 x 17.56

= 12.3 m3/s

Take 20% margin on discharge capacity. So FD Fan flow is 1.2 x 12.3 = 14.76 m3/s

Head required = Draft loss across Air Heater + Grate + Ducting & others

= 75 mmWC + 75 + 50 mm : Approximate

= 200 mm WC (approximate)

Take 15-20 % margin on head. So FD fan head should be about 230 mm of WC.

Therefore, FD fan rating is 15 m3/s of air at 230 mm WC static head.

<span>Power requirements of FD Fan</span> :

Let us assume Fan efficiency as 75% and Motor Efficiency as 90%.

Power required for FD Fan, BHP = Flow x Head / (Efficiency x 75.8)

= 15 x 230 / (0.75 x 75.8)

= 60.7 HP

Motor HP required = 60.7 / 0.9 = 68 HP

Annual cost of operation assuming 7 cents per KWH and 7200 hrs of operation per annum. 0.74 is factor for converting HP to KW. Pl note that unit Electricity charges vary widely across different countries.

= 68 x 0.74 x 0.07 x 7200

= $ 25, 362 /-

c) Sizing calculations of SA Fan :

Secondary Air Fan (SA fan) supplies secondary combustion air in to the furnace.

Secondary Air , 30% of total , m3/s = 0.3 x 17.56

= 5.27 m3/s

Take 20% margin on discharge capacity. So SA Fan flow is 1.2 x 5.27 = 6.3 m3/s

SA fan static head is about 630 mm WC.

Therefore, SA fan rating is 6.3 m3/s of air at 650 mm WC static head.

Power requirements of SA Fan :

Let us assume Fan efficiency as 70% and Motor Efficiency as 90%.

Power required for FD Fan, BHP = Flow x Head / (Efficiency x 75.8)

= 6.3 x 650 / (0.7 x 75.8)

= 77.1 HP

Motor HP required = 77.1 / 0.9 = 86 HP

Annual cost of operation assuming 7 cents per KWH and 7200 hrs of operation per annum. 0.74 is factor for converting HP to KW. Pl note that unit Electricity charges vary widely across different countries.

= 86 x 0.74 x 0.07 x 7200

= $ 32,075 /-

d) Sizing calculations of ID Fan :

Induced draft fan or ID Fan is required to evacuate the exhaust gases from Boiler to atmosphere through Duct collectors and chimney. Usually ID should take care of draft loss across the Boiler from furnace to Air heater and then draft loss across Duct Collectors like ESP, Wet Scrubber or mechanical type Cyclone dust collectors .etc.

Total wet gases, Kg/hr = 79,228

Gas Density = 1.3265 Kg/Nm3

Therefore, gas flow in Nm3/hr = 79,228 / 1.3265

= 59227 Nm3/hr

= 16.6 Nm3/s

Gas flow at 150C in m3/s = 16.6 x (273+150)/273 = 25.7

ID Fan capacity taking 20% margin on flow = 25.7 x 1.2

= 30 m3/s

ID Fan static Head = Draft Loss in (Boiler + Duct + Dust collector)

= 150 + 50 + 50 mm WC : Approximate

= 250 mmWC

Taking 20% margin on head, ID Fan head = 250 * 1.2 = 300 mm WC

<span>Power requirements of ID Fan</span> :

Let us assume Fan efficiency as 75% and Motor Efficiency as 90%.

Power required for ID Fan, BHP = Flow x Head / (Efficiency x 75.8)

= 30 x 300 / (0.75 x 75.8)

= 158 HP

Motor HP required = 158 / 0.9 = 175 HP

Annual cost of operation assuming 7 cents per KWH and 7200 hrs of operation per annum. 0.74 is factor for converting HP to KW. Pl note that unit Electricity charges vary widely across different countries.

= 175 x 0.74 x 0.07 x 7200

= $ 65,268 /-

BFW pumps

BFW pumps

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Fault Listing for DDCC S320 for SAACKE Burner user with DDCC BMS

Fault Listing for DDCC S320

This fault has occurred for one of the following reasons:

F1 – Gas incorrect position

A drive positioning fault has occurred, which will cause a safety shutdown of the burner.

F2 -Oil incorrect position

During close position prove, when a drive stops at a position which is outside the close set position by more than five degrees.

F7 – Sec.air damper incorrect position

During purge position prove, when a drive stops at a position which is outside the close set position by more than five degrees

F9 – Prim.air damper incorrect position

During pre purge, ignition or post purge, when a drive moves from its set point.

F10 – Recirc.air damper incorrect position

During modulation, when a drive is not at its correct set point as defined by the commissioned fuel/air ratio for the selected profile.

F8 Variable speed incorrect position

A drive is defined as having moved from its set point if its positional error is more than 1o for 15s, or more than 5o for 1s.

SAACKE

DDCC

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Man killed, 11 others injured in steam boiler explosion

Danger awaits if safety has been neglected.

DAVAO CITY, Philippines – A man died while 11 workers were injured after a steam boiler exploded in a wood factory in Bunawan village in the city Monday afternoon.

An initial investigation conducted by SPO1 Mariano Operario, investigator of the Bunawan police station, identified the fatality as Austio Albelda, 41, resident of purok Leo, Lasang, Davao City.

Albelda worked as a laborer at Chaverson Wood Industry Corporation located at sitio Matarlo, Mahayag, Bunawan.

The injured victims, who were all brought to the Davao Medical Center for minor wounds, were identified as Guillen Jacaac, Echon Entino, Reil Cagaan, Gabriel Serrano, Amelia Ocaba, Elena Gregori, Rene dela Torre, Felipe Alonzo, Elizer Restauro, Jomel Pagalan and Sofronio Niño. All are workers of the said factory.

According to Operario’s report, the steam boiler exploded around 2:45 p.m. when its safety valve malfunctioned.

Albelda was declared dead on the spot.

Authorities are set to conduct further investigation on the incident. – Sun.Star

Taken from boilerexplosions.blogspot.com

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Please gave your opinion on how prevent this accident..

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