close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2090328

код для вставки
Aug» 1.7, 1937.
H. o. HALDEN
FURNACE
Filed Aug. 8, 1935
2,090,328
’
Patented Aug. 17, 1937
2,090,328
UNITED STATES PATENT OFFICE
2,090,328
FURNACE
Herbert O. Halden, Kansas City, Mo., assignor to
Riley Stoker Corporation, Worcester, Mass., a
corporation of Massachusetts
Application August 8, 1935, Serial No. 35,337
Z Claims.
This invention relates to furnaces, and more
particularly to the construction and operation of
plants having two separate furnaces adapted to
burn two different fuels.
5
'I‘he embodiment illustrated in Fig. 1 comprises
a steam-generating furnace III of suitable con
struction having a steam boiler II associated
therewith. The boiler II is of a well-known
In many establishments there is available a
water tube type having transverse drums, in-
limited quantity of waste material, such as wood
refuse, which has an appreciable heating value.
'I'his material must be burned and the heat there
cluding a lower rear water drum I2 and an upperk
from utilized. »At the same time it may be neces
10 sary to burn another fuel, such as coal, for the
generation of steam. While it is possible in
some cases to burn both fuels in a single furnace,
it is often difficult to design a furnace which will
operate satisfactory and eiiiciently under such
15 conditions. On the other hand, if two furnaces
are utilized, it is undesirable for many reasons
and particularly from the economic viewpoint to
provide a separate steam boiler and a separate
stack for each. A difficult problem is therefore
20 presented as to how the heat from the fuel can
best be recovered and the necessary draft for
both furnaces obtained. Further problems are
presented in avoiding heat losses caused by eX
cess air in the refuse-burning furnace, and in so
g5 constructing this furnace as to facilitate the in
troduction of fuel.
It is accordingly one object of the invention
to provi-de a simple and eiiicient apparatus for
burning two different fuels and recovering the
30 heat therefrom.
It is a further object of the invention to com
bine a refuse-burning furnace with a steam
generating furnace fired with a different fuel,
and to obtain efficient combustion of both fuels,
35 adequate recovery of heat, and a long life for the
apparatus required.
It is a further object of the invention to com
bine a refuse-burning furnace with a steam
generating furnace fired with a different fuel, to
40 make possible the introduction of the refuse into
its furnace in a simple manner, and to maintain
a high over-all eñ‘iciency.
vWith these and other objects in view, as will be
appar-ent to those skilled in the art, the invention
45 resides in the combination of parts set forth in
the specification and covered by the claims ap
pended hereto.
'
Referring to the drawing illustrating one em
bodiment of the invention, and in which like
50 reference numerals indicate like parts,
Fig. 1 is a somewhat diagrammatic view show
ing a refuse-burning furnace in section and an
I
(o1. 11o-2s)
associated steam-generating furnace in elevation;
and
55 Fig. 2 is a fragmentary View of a modification.
5
front water drum I4. It will be understood that
the drums are connected by tubes (not shown)
which form the boiler heating surfaces.
The furnace I0 is ñred with any suitable fuel, 10
and for this purpose I have shown a pulverizer
I5 provided with the usual regulatable feeding
mechanism I6 and arranged to supply pulverized
coal and primary air through a pipe I'I to a
burner vI8 mounted on the furnace wall. The 15
secondary air necessary for complete combustion
of the fuel is supplied by means of a forced
draft fan 20 connected to the burner I3 by a
duct 2 I. This duct may be provided with damp
ers 22 to control the rate of air flow. The furnace
Iû is provided with the usual outlet duct 24 for
the escape of the gaseous products of combustion
after they travel past the boiler heating surfaces.
This duct 24 may lead to a stack (not shown),
and a damper 25 may be provided in the duct to
control the rate of gas flow.
A separate furnace or incinerator 2'I is pro
vided for the burning of waste material, such as
wood refuse, and this incinerator is preferably
open at the top to facilitate the introduction of ‘
the fuel. This construction is made possible by
utilizing a down-draft grate of the water cooled
type, and for this purpose I preferably utilize a
row of horizontally spaced water tubes 28 which
extend across the furnace between a lower header 35
29 and an upper header 30. The lower header is
connected to the boiler drum I2 by means of a
pipe 32, and the upper header is connected to the
boiler drum I4 by means of a pipe 33. The grate y
is thus connected into the circulation of the boiler he.
I I. The iiow of water through the grate may be
accelerated by providing the tubes 28 with steeply
sloping portions 34 located Within the furnace
and exposed to contact with the burning fuel.
A door 35 is preferably located in the furnace wall 45
just above the tubes 28.
A second grate 3'I extends across the furnace
beneath the tubes 28 to catch fuel which may
drop through between the tubes. The grate 31
may be of the ordinary up-draft type, and a door 50
38 is preferably provided'in the furnace wall just
above this grate.
The space 39 below the grate
3'I is utilized as an ash pit, and a door 40 is pro
vided in the furnace wall to facilitate removal of 55
2
2,090,328
the ashes, and to supply air for combustion of the
fuel on the grate 31.
In order to provide sufficient draft to burn the
refuse in the incinerator 21 and withdraw the
doors 35 and 38. Water circulates through the
tubes 28 to protect them from overheating.
Since there is no substantial absorption of heat
gaseous products of combustion therefrom, I pro
from the gaseous products of combustion in the
furnace space 43, and since there is no heat
vide a duct 42 which connects the combustion
space 43 between the grates 28 and 31 with the
the fan. 20, these gases may be at a very high
inlet of the fan ‘20. This duct is provided with
an inlet 44 through which comparatively cool air
10 may be admitted to mix with the gases before they
enter the fan.
absorption apparatus between the grate 28 and
temperature, say 2500 degrees Fahrenheit, which
is much too high for any ordinary fan to With
stand.
The suction of the fan, however, causes 10
In this way the fan is protected „comparatively cool air to enter through the in
from high temperature gases which might cause
let 44 and mix with the gases, thus reducing their
damage thereto, and sufficient air is provided to
support the combustion of the pulverized coal.
I preferably control the ratio between the quan
tity of gaseous products withdrawn from the fur
temperature to a value considered safe, say 600
degrees Fahrenheit, while at the same time pre
steam boiler furnace I0.
nace 21 and the quantity of air mixed with these
maintain this temperature substantially constant ,
products. By varying this ratio, it is possible to
control the temperature of the mixture and pre
20 vent it from exceeding a predetermined maxi
mum. In the preferred construction illustrated,
a damper 46 is mounted in the air inlet 44, and
this damper is actuated by means of an automatic
regulator 41 connected to the damper by a rod 48.
The regulator 41 is controlled by a temperature
responsive device 5D mounted in the duct 2I and
connected tothe regulator by a tube 5I . The reg
ulator 41 and control device 5B may be of any
suitable construction, apparatus of this type be
ing well-known and in common use in many arts.
It will be apparent that the temperature of the
gaseous mixture could be controlled by other
means, such as a damper located at the outlet
from the combustion chamber 43. However, such
' a damper would be exposed to very high temper
atures, Whereas the damper 46 is located in a
stream of comparatively cool air.
The operation of the invention will now be ap
parent from the above disclosure. Coal is deliv
40 ered to the pulverizer I5 at a controlled rate by
v the feeder I 6, and the pulverized coal and pri
mary air pass through the pipe I1 to the burner
i8. Secondary air is supplied through the duct
2l by the fan 20, and the coal burns in suspen
45 sion in the furnace IG, the .gaseous products of
combustion fiowing past the heating surfaces of
the boiler I I and generating steam.
The gases
escape through the outlet duct 24, and the damp
er 25 is preferably controlled either manually or
50 automatically to maintain a pressure in the fur
nace IB slightly below atmospheric pressure, thus
protecting the furnace Walls from overheating
without allowing excessive air infiltration. The
supply of coal and air is varied in accordance with
55 the demand for, steam, the variation in coal sup
' ply being effected by adjustment of the feeder
IG, and the variation in air supply being effected
by adjustment of the dampers 22 or by changing
the speed of the fan 20.
`Waste materiaL'such as wood-refuse, is depos
60
lted in the incinerator 21 through the open top
thereof and is supported on the water tubes 28.
Such particles as fall through between the water
tubes will be supported by the lower grate 31.
65 The deposit of the refuse maybe made whenever
convenient, and need bear no definite relation
ship to the demand for steam from the boiler I I.
The fan 2B will maintain a sub-atmospheric pres
sure in the combustion space 43, drawing air
70 downwardly between the water tubes 28 and up
wardly through the grate 31 to support combus
tion of the refuse. Ash will fall through the
grate 31 into the ash pit 39 and can be removed
through the door 4B. The fire can be poked or
75 otherwisemanipulated if necessary through the
heating the <air forcoinbustion of fuel in thev 15
The regulator 41 will
by adjusting the damper 46 automatically to ad
mit more or less air whenever the temperature
'20
tends to rise or fall.
The combustion rates in the incinerator 21 and
furnace I0 will be maintained in a substantially
constant ratio, and the mixture flowing in the
duct 2l will contain a substantially constant per
centage of air, so long as sufficient refuse is sup
25
plied >to the incinerator 21 to prevent the tem
perature of the mixture from dropping below the
value for which the regulator 41 is adjusted. If
excess air is present in the combustion chamber
43, it will lower the temperature of the gases 30
escaping therefrom, and the regulator will par
tially close the damper 46, thus maintaining the
temperature of the mixture and the proportion of
air therein substantially constant. The heat lib
erated by combustion of the refuse will be utilized
for generation of steam in the boiler I I. In case
no refuse is being burned, the fan 2D will handle
air only, and it will be necessary to reduce the
air flow in proportion to the coal feed to main
tain the desired fuel-air ratio for the furnace I0.
Under these conditions the fan 20 may draw its
air supply through the incinerator 21, or the
damper 46 may be disconnected from the regu
lator 41 and placed in a Wide open position to
admit air through the inlet 44.
In the modification illustrated in Fig. 2, means
is provided to admit air through the inlet 44 if
required for the combustion of the pulverized
fuel, irrespective of the position of the automatic
regulator 41. For this purpose, the damper 46 is 50
replaced by an unbalanced damper 60 which tends
to open upon a decrease in pressure in the duct
42. This damper is Aprovided with an arm 6I to
which a weight 62 is adjustably secured. lThe
arm 6I is connected to the regulator 41 by means 55
of a flexible cable 64. The weight 62 and asso
ciated parts normally maintain the cable 64 taut,
but if the» air requirements are such as to cause
an excessive suction in the duct 42, the damper
will open to admit more air, and the cable will 60
slacken.
'
It will be apparent from the above description
that I have provided apparatus for burning two
fuels which represent a considerable advance in
the art. Ample draft is available for both the 65
incinerator and the steam boiler furnace, and
the apparatus is comparatively simple and inex
pensive. rI‘he fan is automatically protected from
over-heating. ' The waste material can beeasily
and conveniently deposited in the incinerator, and 70
the heat from this fuel will be efficiently recov
ered. 4If excess air enters the incinerator, it will
not 'affect the over-al1 efficiency of the installa
tion, since such air will be utilized to support
combustion of »the coal,
2,090,328
Having thus described my invention, what I
claim as new and desire to secure by Letters Pat
ent is:
_
1. Fuel burning apparatus comprising a. fur
nace, means to supply fuel to the furnace for
combustion therein, a steam boiler associated With
the furnace, a rotary fan arranged to supply air
at a pressure above atmospheric to the furnace
to support the combustion of the fuel, means to
10 supply air to the fan, an incinerator, a grate in
the incinerator to support fuel thereon, and means
to conduct the gaseous products of combustion
directly from the incinerator and mix them with
3
nace, means to supply fuel to the furnace for
combustion therein, a steam boiler associated with
the furnace, a rotary fan arranged to supply air
at a pressure above atmospheric to the furnace
to support the combustion of the fuel, means to
supply air to the fan, an incinerator, a grate in
the incinerator to support fuel thereon, means to
conduct the gaseous products of combustion di
rectly from the incinerator and mix them With
the air supplied to the fan without the interven 10
tion of heat absorption apparatus between the
grate and the fan, thereby reducing the temper
ature of said gaseous products of combustion and
the air supplied to the fan without the inter- i preheating the air before they enter the fan, and
vention of heat absorption apparatus between the
grate and the fan, thereby reducing the temper
ature of said gaseous products of combustion and
preheating the air before they enter the fan.
2. Fuel burning apparatus comprising a fur
means to control the ratio between the volume of 15
said gaseous products of combustion and the vol
urne of the air supplied to the fan in accordance
with the temperature of the mixture.
`
HERBERT O'. HALDEN.
Документ
Категория
Без категории
Просмотров
0
Размер файла
426 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа