ash disposal system

8/11/2019 Ash Disposal System

1/10

Q j Y i

European

Patent

Office

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Office

europeen

des

brevets

yi)

Publication

number: 0

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^ c u r tu r tMIM KAItlMI APPLICATION

Application

number:

80107837.9

@

|nt.

CI.3:

F

23 J

1/02

Date of

filing:

11.12.80

S)

Priority:

13.12.79 US

102722

Applicant:

COMBUSTION

ENGINEERING,INC.1000 Prospect Hill Road

_

, , ,.

Windsor,

Connecticut

06095IUS)

) Date

of

publication of

application

:

01.07.81

Bulletin

81/26

Inventor:

Cozza,

Anthony

James

17

Rockwell

Place

^

S? d

Contracting

States:

West

Hartford

Connecticut(US)

DE FR GB

SE

@

Inventor:

Singer,

Joseph Gerard

28

Burnwood

Drive

Bloomfield

Connecticut(US)

Representative:

Patentanwalte

Henkel-Kern-Feiler-Hanzel

Mohlstrasse

37

D-8000

Munchen

80(DE)

S

,

1

..........

uuni(,i

yCU

OOiapCI.

Apparatus

for

handling

ash

and

slag

produced

in

the

combustion of

coal

or

other

ash-bearing

fuel in

the furnace

(10)

of

a

steam

generator, including

an

ash

hopper

(14)

beneath

the furnace into

which

the ash

initially

falls.

A

pair

of

scraper

conveyors

(30,32) which

are submerged

in

water

are

located

below

the

ash

hopper

(14)

from

which

the ash is

continuously disposed

of. Water

nozzles

(40)

are

located

in

the

ash

hopper

(14)

for

cooling

and

moving

the

ash.


2/10


3/10

The

i n v e n t i o n

r e l a t e s

to

an a s h - d i s p o s a l

s y s t e m

f or a s h e s

d i s c h a r g e d

f ro m

a

c o a l - f i r e d

or

o t h e r

a s h - b e a r i n g

f u e l -

f i r e d

c o m b u s t i o n

c h a m b e r .

In

c o a l - f i r e d

s t e a m

g e n e r a t o r s ,

th e

ma n n e r

i n w h ic h t h e

ash

is

h a n d l e d a n d

d i s p o s e d

of is

an

i t e m

of

c o n s i d e r a b l e

i m p o r t a n c e .

The

e q u i p m e n t

fo r

h a n d l i n g

t h e . a s h ca n no t

o n l y

be

c o s t l y ,

b u t

i f

i t

r e q u i r e s

much

m a i n t e n a n c e ,

i t

can

a l s o

l e a d

to

u n t i m e l y

and

l e n g t h y

s h u t - d o w n s o f

t he e n t i r e

s t e a m

g e n e r a t o r .

T h e i n v e n t i o n

as

c l a i m e d

i s i n t e n d e d t o

p r o v i d e

a

r e m e d y

by p r o v i d i n g

an

a s h - h a n d l i n g or

a s h - d i s p o s a l

s y s t e m

f o r

th e

f u r n a c e s

of

s te a m

g e n e r a t o r s ,

i n c l u d i n g

a n

ash

h o p p e r

b e n e a t h

t h e f u r n a c e

i n t o

wh ic h

t h e

ash and

s l a g

i n i t i a l l y f a l l s . A p a i r of

s c r a p e r c o n ve y o r s

wh ic h are s u b -

me rg e d

i n w a t e r

a re

l o c a t e d b e l o w

the ash

h o p p e r

from

w h i c h

th e

ash

is

c o n t i n u o u s l y d i s p o s e d

o f .

Wa te r

n o z z l e s

a r e

l o c a t e d i n t h e a sh

h o p p e r

fo r

c o o l i n g

and moving

t h e a s h .

One

way

of

c a r r y i n g

out

t he i n v e n t i o n

is

d e s c r i b e d

i n d e -

t a i l b e l o w

w i t h

r e f e r e n c e

to

d r a w i n g s

wh i c h i l l u s t r a t e

o n l y

one s p e c i f i c

e m b o d i m e n t

i n w h i c h :

F i g u r e

1

is

a

c r o s s - s e c t i o n a l

s i d e

v ie w

of

th e

ash

h a n d l i n g

a p p a r a t u s

f o r

th e

f u r n a c e o f

a

s te a m

g e n e r a t o r ;

a n d

F i g u r e

2 is

a

v i e w t a k e n

on

l ine 2-2 of

F i g u r e

1 .

R e f e r r i n g

to

F i g u r e

1,

numera l 10

d e n o t e s

t h e f u r n a c e

b o t t o m

o p e n i n g

of

a

c o a l - f i r e d

s te a m

g e n e r a t o r ,

t h r o u g h

which

m o l t e n

ash

and

s l a g

a re d i s c h a r g e d .

A wa te r

s e a l

12

p e r m i t s

t h e r m a l

e x p a n s i o n of th e t o p - s u p p o r t e d f u r n a c e , w h i l e p r e v e n t i n g

e x p o s u r e

of t he i n t e r i o r of a sh

h o p p e r

14

to

th e

a t m o s p h e r e .


4/10

Ash

f a l l s

into the ash

hopper

(Figure

2),

s l i d i n g

down

the

a n g l e d

f lo o r

to

one

o f - t h e

openings

18,20.

These

openings

can

be

c losed

b y

gates

22 ,-24 when

n e c e s s a ry ,

as

l a t e r

descr ibed . This

hopper

m a y o r

may

not be

r e f r a c t o r y - l i n e d

and

may or may

not

be

w a t e r - c o o l e d .

The ash fa l ls through the openings 18, 20 into one or t h e

other

of

the

l o n g i t u d i n a l

tanks

26,

28. Each tank

conta ins

a

s c r a p e r

conveyor

30, 32,

the

upper

runs

of

which

a re s u b me rg e d ,

or

l o c a t e d

beneath

the

water

level maintained in

each tank.

The

upper

runs

o f

the

conveyors

carry

the c l inkers

to

the

end

o f t h e

tanks ,

where

t h e y

can

be

discharged

into

trucks

or

onto

mechanical

conveyors

(not

shown)

and

t r a n s p o r t e d

away.

A

p o r t io n

of

the

water

in

the

tanks

is

c o n -

s t a n t l y

removed and

re p le n i s h e d

to

maintain the

main

body

of

w a t e r

at

a te mp e ra tu re

not

exceeding

160F

( 7 1 C ) .

In normal

o p e r a t i o n ,

the

conveyors

are

in

c o n s ta n t

o p e r a -

t io n ,

continuously removing

ash.

When

one

of the

conveyors

need

r e p a i r ,

i t s

c o r re s p o n d in g

gate

valve,

for

example 22,

can

be

c l o s e d ,

so

all of the ash is

then

discharged

through

opening

20 into tank

28.

Tank

26

can

then

be drained so -t ha t the

conveyor

30,

or

o ther b roken

equipment, can

be

re p a i re d

without

n e c e s s i t a t i n g

shutdown

of the

s team

g e n e r a t o r .

If both

conveyors

need

some

minor

r e p a i r s s i m u l t a n e o u s l y ,

both

gate

valves 22 and 24

can

be closed. Water from the nozzles 40

can

then

be used.to

fi ll the ash

hopper

14

to

a

g i v e n l e v e l ,

and

t h e

ash

can

be

t e m p o r a r i l y

stored in

the

ash

hopper

for

a

s h o r t t ime

while

minor

r e p a i r

or

maintenance work is done

to

the

conveyors .

An

overf low

pipe

42

keeps

the water at

a

c o n s ta n t

level

during

th is

t y p e

of

o p e r a t i o n .

The

water

nozzles 40

provide

an

a d d i t i o n a l

fu n c t io n .

During

normal

o p e r a t i o n ,

they

d i r e c t

j e t s

or

sprays

of

water

onto the

f a l l i n g

ash, thus provid ing h y d r a u l i c f r a c t u r i n g and s l u i c i n g o f l a rg e a s h

p a r t i c l e s ,

p revent ing

the

openings

18 and 20

from

becoming clogged.

A l t e r n a t i v e l y ,

the

gates

can

be

kept

c losed ,

and

the ash

hopper

n o r -

mally

f i l l e d

with

water.

The

gates

could then

be

i n t e r m i t t e n t l y

opened

to

allow

d is c h a rg e

of the

a s h .

From

the

above,

i t

can

be

seen

tha t

in

normal

o p e r a t i o n ,

the

ash

is

c o n t i n u o u s l y

removed

by

both

of the

scraper

c o n v e y o rs .

Fa l l in g

ash

from

fur nace 10 st ri ke s sur fac e 16 of

the

ash

h o p p e r ,

p re v e n t in g

damage

to the

conveyors

30,

32. The

drop

from

the

a s h


5/10

hopper

bottom to

the

conveyors

is

r e l a t i v e l y

short

compared

to

t h e

he igh t

of

the

ash

hopper.

When

re p a i r

work is

required

on

one

of

the conveyors , the ash is removed by the other one. This is

accomplished

without

the

n e c e s s i ty

of

moving

the tank

and

conveyor

and

also

without

s h u t t in g

down

the steam

g e n e ra to r .

In

a d d i t i o n ,

minor maintenance

can

be done to

both

of

the

conveyors

while

t h e

ash

is

t e mp o ra r i ly

stored

in

the

ash

hopper

14.

Ce r ta in ly ,

t h e

length

of time

of this

o p e ra t io n

is l imited

by

the ash

s t o r a g e

c a p a c i ty

of

the

hopper

14.


6/10

1.

An


s y s t e m

f o r a s h e s

d i s c h a r g e d

from

a

c o a l - f i r e d

or

o t h e r

a s h - b e a r i n g

f u e l - f i r e d

c o m b u s t i o n

c h a m b e r

( 1 0 ) ,

i n c l u d i n g

an

ash

h o p p e r

(14)

p o s i t i o n e d

b e n e a t h

t h e

c o m b u s t i o n

c h a m b e r

(10)

i n t o w h i c h t h e

ash

f a l l s ,

s p r a y

n o z z l e s

(40)

f o r

d i r e c t i n g

w a t e r

j e t s

o n t o t h e

f a l l i n g

a s h ,

a p a i r

of

o p e n i n g s

( 1 8 , 2 0 )

in

o p p o s i t e

w a l l s of t h e a s h

h o p p e r

(14)

a d j a c e n t

to

t h e b o t t o m

t h e r e o f ,

a

p a i r

of

t a n k s

( 2 6 , 2 8 )

l o c a t e d b e n e a t h t he

ash

h o p p e r

( 1 4 ) ,

e a c h

b e i n g

b e n e a t h t h e r e s p e c t i v e ash h o p p e r o p e n i n g s ( 1 8 , 2 0 ) , m e a n s

f o r

m a i n t a i n i n g

a g iv e n

l e v e l o f

w a t e r

in e a c h t a n k

( 2 6 , 2 8 ) ,

and

c o n v e y o r

means

( 3 0 , 3 2 )

l o c a t e d

in e ac h t a n k b e n e a t h t h e

w a t e r

l e v e l f o r

r e m o v i n g

ash f rom the

t a n k s

( 2 6 , 2 8 ) .

2.

The


s y s t e m

of

Cla im

1,

i n c l u d i n g

a

p a i r

of

g a t e

v a l v e s

( 2 2 , 2 4 )

a s s o c i a t e d w it h t he

a s h - h o p p e r

o p e n i n g s

( 1 8 , 2 0 ) .

3.

The


s y s t e m

of Cla im

2,

i n c l u d i n g m e a n s

f o r

m a i n t a i n i n g

a

g i v e n

w a t e r

l e v e l i n

t h e

ash

h o p p e r

( 1 4 )

when

b o t h

g a t e v a l v e s

( 2 2 , 2 4 )

a r e

in t h e i r c l o s e d

p o s i t i o n s .

4.

The


s y s t e m

s e t

f o r t h i n C l a im

3 ,

i n c l u d i n g

w a t e r

s e a l

means

(12)

b e t w e e n

th e

c o m b u s t i o n

c h a m b e r

(10)

and

th e a s h

h o p p e r

( 1 4 ) ,

an d b e t w e e n t h e a s h

h o p p e r

(14)

a n d t h e t a n k s

( 2 6 , 2 8 ) ,

so

t h a t t h e

dry

a sh f i n e s

c a n n o t

e s c a p e

to

th e

a t m o s p h e r e ,

and

a t m o s p h e r i c

a i r

c a n n o t

e n t e r

t h e

c o m b u s t i o n

c h a m b e r

( 1 0 ) .


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ash disposal system

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