Calderas de Lecho Fluidizado - T&E Calderas y...

Calderas de Lecho Fluidizado

http://www.calderasyenergia.com/

Calderas de Lecho Fluidizado

TIPO

- ACUATUBULARES PARA VAPOR

- HÍBRIDAS PARA VAPOR

- ACUATUBULARES PARA AGUA CALIENTE

- HÍBRIDAS PARA AGUA CALIENTE

- PARA FLUIDO TÉRMICO

COMBUSTIBLES

- CARBÓN

- RESIDUOS DE PALMA

- CACARILLA DE ARROZ

- DESPERDICIOS DE MADERA


Caldera Acuatubular

Background

• German design• Developed by Dr. Heinrich

Vorkauf in 1944• Robust and distinc design

natural circulation boiler• Built to the ASME 1 approved by

Depnaker• Performance Values- Steam rating: from 0.4 to 290 t/h- Steam Pressure: from 8 to 136 bar- Steam temperature: to 535°C- Hot Water Boiler: to 174MW


Desempeño

•Steam rating: from 0.4 to 290 t/h

•Steam Pressure: from 8 to 136 bar

•Steam temperature: to 535°C

•Hot Water Boiler: to 174MW

Potente

Confiable

Caldera Acuatubular


Design Principle

1.Unheated return tubes

2.Header

3.Mixture tubes

4.Riser tubes/evaporator

5.Overflow tubes

6.Unheated steam drum

7.Unheated down comers

Caldera Acuatubular


Advantages1. High water circulation an quick

start up2. High steam Purity3. High efficiency4. Reduce response time with

varying steam demand5. Low pressure variations at turn

down6. Low water side pressure loss7. Self supporting construction8. Small foot Print9. Simple erection with few site

welds

Caldera Acuatubular

Construction1. Tube cage with all welded or separately

supported heating surfaces is self-supported by downcomers in the corners of the boiler (2, 7).

2. No complicated connections between boiler and cold frame.

3. The compact tube system will be manufactured in the workshop under good conditions and sharp quality surveillance.

4. Eckrohr-Boilers can be cut longitudinally or cross wise into several stable pieces for transportation.

Caldera Acuatubular


Simulation10 t/hr 26 barg, Boiler with Fluidized bed Combustor

Assembly of water tube boiler in factory

Caldera Acuatubular


Factory assembled boiler delivered to site

Boiler pressure part installation

Caldera Acuatubular


Lecho Fluidizado BurbujeanteBFB – Blubling Fludized Bed

El mejor sistema de combustión para calderas entre 4 y 100 t/h que usan

carbón como combustible.

Combustión


Cámara de Combustión de Lecho Fluidizado Burbujeante


Main features– Fluid bed consisting of

350 mm layer of silica sand

– Sand of size between 0.5 to 1.5 mm used

– High pressure forced draft fan used for fluidization

Combustor del lecho



Main features– Special construction

stainless steel nozzles – Fluid bed maintained at 700

to 900 °C during operation

Boquillas de aire de acero inox

View of Fluidized bed combustor



Main features

– Sand is fluidized by passing air through nozzles located at bottom of the bed.

– Fuel fed by over-bed screw feeder

– Fluid bed maintained at 700 to 900 °C during operation

Boquillas de aire de acero inox



Advantage of Fluidized Bed Boiler

• Cheaper coal fines used as fuel thus costing about 50 % less. Size of coal required is 100 % below 15 mm.

• 100 % capacity of the boiler can be obtained with nearly all types of coals. No capacity reduction for lower heating value.

Ventajas de las calderas deLecho Fluidizado



• The capacity of boiler is specified at the working pressure with feed water at 30 °C.

Not on F&A 100 °C basis.




• Large external furnace with large volume causes complete combustion of volatile matter. No fouling of boiler due to tar.

• Low Furnace temperature. Causes no fouling of refractory




• Fuel flexibility. Fluid bed furnace can burn a variety of fuels without reduction of boiler output

• Materials like sludge and waste can be incinerated along with the coal




• The combustor can be started immediately after up to 4 hours shut down without any pre heating as the sand bed retains heat

• Very quick turndown is possible and thus very quick load response.



Advantage of Fluidized Bed Boiler The best attributes

• Produces very low NOx and Sox emissions

• Very reliable as the only moving part is the fans which are outside the hot zone

• Higher combustion efficiency (95-99%)



Expected emissions for fluidized bed combustor

• Test parameter • result • limit • Units

• Dust particulate

• bag house filter

• Ventury scrubber

• ESP

• 50

• 100

• 100

• 50 • mg/Nm3

• Nitrogen oxides

• 30 • 300 • mg/Nm3

• Sulphur • 150 • 300 • mg/Nm

Emisiones de las calderas deLecho Fluidizado


Limitations of various dust collector systems

• Cyclone separators - 350 mg/Nm3

• Ventury scrubber - 150 mg/nm3

• Electro static Precipitator - 100 mg/nm3

• Bag filter - 50 mg/Nm3

Control de emisiones calderas Lecho Fluidizado


BOILER SYSTEM• Water tube boiler

• In – bed tube assembly

• Fluidized bed combustor

• Forced draft fans

• Induced draft fans

• Feed water pumps

• Controls

• Cyclone separator

• Ventury scrubber

• Bag Filter

• Chimney

• Deaerator

• Fuel feeding and storage

system

• Feed water Plant

• Ash disposal system

• Economize

• Super Heater

Sistema de generación de vapor


Fluidized bed boiler schematic diagram


Fluidized bed combustor

Stainless steel air nozzles

Fluid bed cooling tube bundle construction

Coal Screw feeder

Belt conveyor for feeding coal to hopper

Dust collection system including cyclone separator and scrubber

Ventury scrubber

Ash removal systemsManual ash lever

Ash removal systemAutomatic ash screw

Control panel

Control panel - Touch screen with mimic diagram

Control panel – Display of Boiler parameters

Control panel - Daily log sheet

Control panel – Graph of Boiler parameters

Furnace draft control

Fluidized bed temperature control

40 t/hr 45 barg rice husk fired boiler

Bubbling fluidized bed boiler

• Uses low furnace gas velocity of 2.5 m/s

• Furnace height is normally 5

meters

• Easy to control due to in-bed tube

bundle

• Suitable for boiler of capacity

below 100 t/hr. There are more

than 200 bubbling fluidized bed

boilers using coal in Indonesia.

• Low Forced draft fan pressure(800

mm Wg) and power consumption

BFB vs CFB


Circulating fluidized bed boiler

• Operates at higher furnace Gas velocity of 7 m/s. This carries most of the bed solids upwards with the gas.

• Solids separated from gas in a refractory lined cyclone separator and returned to the fluid bed.

• Gives higher combustion efficiency

BFB vs CFB


Circulating fluidized bed boiler Disadvantages• Needs very tall furnace to get adequate

residence time for carbon. Normal furnace height is 15 meters

• Needs very high Forced draft fan pressure of nearly 2000 mm Wg. This means very high power consumption

• Used for boilers above 100 t/hr capacity• The boiler is difficult to control due to

unstable bed temperature. Needs very sophisticated control

• The hot cyclone is refractory lined and needs lot of maintenance causing plant shut down

• The Chinese CFB of 20 – 50 t/hr capacity has shown lot of operation problems in Indonesia and customers have shut down most of these boilers

• Operates at higher furnace Gas velocity of 7 m/s. This carries most of the bed solids upwards with the gas.

• Solids separated from gas in a refractory lined cyclone separator and returned to the fluid bed.

• Gives higher combustion efficiency

BFB vs CFB


Problems of Bad Fluidized Bed Boiler

• Frequent erosion of Bed tubes• Fluidizing nozzles of wrong design

– Air nozzle of 150 mm dia. with large size holes– Large distance between nozzles

• Bed temperature is higher than 1000 °C since the in-bed cooling tubes are not adequate

• Unable to achieve 100 % load• Pressure part made in China• Difficult to change in bed tubes

Problemas de calderas deficientes de

Lecho Fluidizado


In – Bed tubes in Hamada Boiler

Hamada air nozzle Basuki air nozzle

Hamada air nozzle New After use

www.calderasyenergia.com

Ing. Daniel de los Rí[email protected](57) 3214493924

FIN DE PRESENTACION Calderas de Lecho Fluidizado

http://www.calderascolombia.com/

mailto:[email protected]


Calderas de Lecho Fluidizado - T&E Calderas y...

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