16 ECOTHERM Steam Solutions

Feed Water Tanks & Deaerators

DescriptionThe feedwater deaerating plant, consisting of the feedwater tank and the deaerator, removes dissolved gases such as oxygen, carbon dioxide and other non-condensable gases from boiler feedwater and makeup water.For the operation of steam boilers with high thermal load on the heating surfaces boiler feedwater must be treated and conditioned.The boiler feedwater must be free of hardening constituents in order to prevent the formation of scale on the boiler heating surfaces. The presence of dissolved oxygen and carbon dioxide causes severe corrosion of metal boiler parts. The feedwater deaerating plant is custom designed for each application and meets essential thermo dynamic requirements to achieve optimal performance.

FunctionThe make-up water and return condensate enters the deaerator that is fitted with a series of tray compartments to provide maximum spilling. Heating steam is fed into the deaerator from below. The make-up water and return con-densate are deaerated and flow directly into the feedwater tank, which is flanged to the deaerator. The feedwater tank, which is heated by means of a steam injector, heats up the feedwater to 105°C. The solubility of gases in water can be described by Henry Dalton‘s law of absorption which states that gas solubility in a solution decreases as the gas partial pressure above the solution decreases. This means that the gas solubility in a solution decreases as the temperature of the solution rises and approaches saturation temperature.The make-up water and return condensate is distributed over the series of trays and comes in direct contact with the heating steam. This process reduces the solubility of oxygen and carbon dioxide and removes these gases from the feedwater. The released gases work their way to the top of the vessel where they are vented from the deaerator via the vent line.A temperature-controlled heating system for warming up a cold feedwater tank is provided. Due to the fact that the feedwater temperature is above 100°C enough net positive suction head (NPSH) is required to ensure that the weight of the column of water in the line exerts enough pressure at the feed water pump suction to prevent the formation of steam bubbles and therefore the water from cavitating. Therefore a support construction is required.

Benefits:• Sizes from 200 to 20,000 litres

• Pressureless or pressurized

• Materials: mild steel, stainless steel AISI 304 / 316

• Completely preassembled unit

• All valves, pumps, instruments are

custom-designed according to

steam boiler system

Find technical specifications on pages 60 - 61.

Products: Feed Water Tanks

FLASH STEAM HEATRECOVERY (OPTIONAL)

DISCHARGING AIRAND OXYGEN TOVENT out of building

VENT PIPE OUTOF BUILDING

OVERFLOW TO DRAIN

FEED WATERRETURN (OPTIONAL)

FEED WATER TANK

BOILERFEEDWATER

DRAIN

PRE-HEATINGTEMPERATUREREGULATION

DEGASIFICATIONPRESSUREREGULATION

LEVELCONTROL

CONDENSATE RETURN

PRESSURE REDUCING STATION(OPTIONAL)

DRAIN

OPERATING PRESSURE

MAKE-UP WATER

0.2 - 0.3 bar (105°C)

SAMPLEWATER

CONDENSATE RETURN FROM STEAMBOILER

PRESSURIZED FEED WATER TANK

TITS TS

1

2

3

4 5 6

7

8

9

10

11

12

13

14

1516

17

8

17ECOTHERM Steam Solutions

1 FeedWaterTank:preparing feed water for steam boilers, collecting condensate, adding chemicals, pre-heating of feed water.

2 PressurizedDeaerator:removing oxygen and other gases, injection for fresh softened water, pressure control

3 LevelControl:to keep a constant water level in the tank a level control system is required. Also protection against low and high water is installed.

4 Drain:for draining of the tank5 Boilerfeedwater:feed water supply connection to

feed water pumps and boilers6 Samplewater:connection to feed water sample

cooler. Water quality needs to be checked daily7 Pre-heating of feed water to protect the boiler

against too high temperature differences and heat tensions, feed water needs to be pre-heated by steam injection.

8 Condensatereturn:collecting the condensate from different consumers, e. g. steam pipe draining points, heat exchangers, laundry machines.

9 Pressure reducing station to provide exact needed pressure for pre-heating and degasification, steam pressure can be adjusted by pressure reducing station

10 Degasificationpressureregulationfor removal of different gases from the feed water, a steam injection in deaerator is necessary. This injection should keep a constant tank pressure of about 0.3 bar(g) for optimal degasification

11 Discharging air and oxygen vent (out of building) removing port of waste gases. also a vapour heat exchanger (flash steam) can be installed on this port. (17)

12 Safety valve high pressure protection valve opens when pressure increases.

13 Feedwaterreturn(optional):in big boiler systems a 3-way valve control for feeding of steam boilers is proposed. In case of low load feed water will be returned to feed tank.

14 Vacuumbreaker:protection against negative pressure

15 Overflow:protection against high water16 Manhole/handhole:will be provided for easy

inspection and cleaning17 FlashSteam(Vapour):heat exchanger uses the

“waste energy” to heat up make-up water before entering the deaerator

Products: Feed Water Tanks

L2N10 N9

N11

N16

N6

N17

N5 N3N4N1N12N18

N7

N7

N2N13

L1L

H D

60 ECOTHERM Steam Solutions

Feed Water Tanks

Sizing in accordance to customer requirementsSubject to change without change

Type ESWB 1 2 3 4 6 8 10 15 20Volume [m3] 1 2 3 4 6 8 10 16 20D [mm] 800 1,100 1,200 1,350 1,500 1,550 1,650 2,100 2,200L [mm] 1,500 1,750 2,250 2,500 3,000 4,000 4,000 4,000 5,000L1 [mm] 1,900 2,200 2,900 3,100 3,600 4,600 5,000 5,100 6,200L2 [mm] 800 1,200 1,200 1,300 1,500 2,000 2,100 2,000 2,500H [mm] 1,100 1,500 1,600 1,750 1,900 2,000 2,000 2,500 2,600Inspection Flange DN 200, PN 6 400, PN 6 500, PN 6Pressure sensor N2 G if required ½Safety valve N3 DN sizing in accordance with required heating capacityVacuum breaker N4 DN sizing in accordance with required heating capacityDeaerator dome N5 DN 250 350 350 450 550 550 650 800 1000Overflow N6 DN sizing in accordance with flowrateWater level N7 DN 15 15 15 15 15 15 15 15 15Feedwater N9 DN 32 40 50 65 80 100 100 150 150Drain N10 DN 25 25 32 32 32 40 40 50 50Heating steam inlet N11 DN sizing in accordance with required heating capacityStand-by N12 DN 40 40 50 50 50 80 80 80 80Thermometer N13 G 1/2Thermostat N16 G sizing in accordance with required mechanical heating-up controllerHeating steam inlet N17 DN sizing in accordance with required heating capacitycondensate N18 DN 25 40 40 50 50 65 65 80 80

Technical Specifications

Material: Mild Steel (P235GH) Stainless Steel (AISI 304 / 316 / DUPLEX)Function: preparation of feed water for steam boiler Pre-heating, deaeration, chemical adding, condensate recoveryDesign: Horizontal Feed Water tank pressureless without deaerator (smaller plants) Horizontal Feed Water tank pressurized with vertical trickling deaerator (bigger plants)Conditions: Max. operating pressure 0.5 bars, test pressure 2 bars Max. operating temperature 120°CFlange Standards: acc. to DIN-EN 1092-1, PN6 / 16 / 40Standards: The product fully complies with the requirements of the European Pressure Directive 97 / 23 / EC and carries the CE mark when so required.Certification: acc. to EN 10204 certifiable as standard and certificates are available on request. Note: All certification / inspection requirements must be stated at the time of order replacement

D

H

N1

N2

N3

N5

N4

61ECOTHERM Steam Solutions

Type EDD 250 350 450 550 650 800 1000Deaerator Capacity [m3/h] 0.5-1.6 1.7-3.0 3.1-5.0 5.1-8.0 8.1-11.0 11.1-15.0 15.1-20.0D [mm] 250 350 450 550 650 800 1000H [mm] 1150 1250 1300 1300 1800 1800 2000Gas vent N1 DN 15 20 25 32 32 40 50Condensate inlet N2 DN 25 40 40 65 80 100 125Make-up water inlet N3 DN 15 20 25 32 40 40 50Pressure gauge connection N4 G 1/2Sensing line N5 G 1/2

Technical Specifications

Material: Stainless Steel (AISI 316 / DUPLEX)Function: preparation of feed water for steam boiler Deaeration of fresh water and condensate, removal of gases.Design: Pressurized vertical trickling deaeratorConditions: Max. operating pressure 0.5 bars, test pressure 2 bars Max. operating temperature 120°CFlange Standards: acc. to DIN-EN 1092-1, PN6 / 16 / 40Standards: The product fully complies with the requirements of the European Pressure Equipment Directive 97 / 23 / EC and carries the CE mark when so required.Certification: acc. to EN 10204 certifiable as standard and certificates are available on request. Note: All certification / inspection requirements must be stated at the time of order replacement

Deaerators

Sizing in accordance to customer requirementsSubject to change without change