Note: Descriptions are shown in the official language in which they were submitted.
1 i553~6
.
¦ Fluid Injectors
This invention concer,ns improvements in or
, relating.to fluid injectors.
, According to the invention there is provided a
fluid injector comprising an injection device, and means
for connecting said fluid injector to fluid delivery and
; return lines, said injection device b~ing capable of being
, removed from an operating po~ition and relative to said
eonnecting means whilst said connecting means is connected
, to the fluid delivery and return lines~ said fluid inJector
being such as to provide for flow between the fluid
delivery and return lines through said connec'ting means
,~ when said injection device is removed whils~.iso~lating
. the fluid delivery and return lines from said injection
device uyon such removal.
_ 15 The invention may be appli'ed to various fluid
injectors. One such injector has a tip shut off facility
and is mechanically,atomised and has a change-over-valve
' which connects~'to a fluid delivery and return circuit as
,~ featured in.our United Kingdom patents Nos. 1,233~317 and
1,~31,631.
Another fluid injector to which the invention
~ ' may bo applied is one of the pressure jet typo which i.s
,I mechnnically atomi.sed and incorporatcs a flui.d atomi~er
at the discharso end and an operatiIlg valve which connects
;~ 25 to a fluid delivery and return circuit.
~3
1 155386
-- 2 --
I A third fluid injector is a multi-fluid injector
¦ with a tip shut off faeility whieh is atomised by a seeond
¦ fluid and includes a means to seleet diseharge of
either fluid or a mixture of the fluids and ineludes a
I ehange-over valve which eonnects to a fluid delivery
¦ and return eircuit. Such an injector is featured in our
United Kingdom patent No. 1,~97,271.
In a fluid injector construeted in aeeordanee
with one preferred embodiment of the invention, interloeking
male and female terminals are arranged so that it is
not possible to eondition the injector for discharge
¦ until the tip valve or the fluid atomiser whichever the
case may be has been inset to the position at which discharge
ean be safely permitted. Conversely, the interloeking
device is arranged so that the tip valve or fluid atomiser
may not be retracted from the position of proper diseharge
without ~irst isolatin$ the fluid supply. In these fluid
injeetors whieh utilize a seeond fluid sueh as the pressure
jettype whieh although meehanieally atomised is both purged
and cooled by a seeond fluid and the multi-fluid
injector having a tip shut off facility which relies
on a~second fluid to assist atomisation as well as for
purging and cooling, then the second fluid is also ported
¦ ~ through the interlocking device so that upon retraction
; 25 of the tip valve or fluid atomiser the supply of second
fluid is also isolated.
In eireumstances whereby the tip valve or fluid
atomiser may be accidentally or unintentionally retracted
; with the change-over valve or operating valve positioned
3 to condition the tip valve or fluid atomiser for fluid
diseharge, the interloeking deviee will operate to isolate
the fluid delivery and return eireuit as well as the
seeond fluid circuit before the tip valve or fluid atomi~er
is retracted from the range of positions at w~ich discharge
¦ 35 ean be permitted.
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1 ~53~6
- 3-
External means may be provided so that in the
evcnt the tip valve or fluid atomiser is accidentally
retracted when conditioned to discharge~ then the change-
over valve or opcrating valve may be automatically
; 5 positioned a~ if to condition the injector for non-discharge.
¦ In order that the invention may ~e well understood
there will now be described some preferred embodiments
thereof~ given by way of example, reference being had to
the accompanying drawings, in which:
Figures lA and lB together comprise a side elevation,
! partly sectioned, of a first fluid injector in an inset
¦ operating position but conditioned for non-discharge;
~ Figures 2A and 2B together comprise a sectioned
.¦ plan view along line II-II of Figure 1;
I 15 Figure 3 is a view corresponding to Figures lA and lB
: showing the same fluid injector not only in an inset
operating position but also conditioned for discharge;
~ Figure 4 is a scrap plan view sectioned along
i line IV-IV of Figure 3;
Figure 5 is a view corresponding to Figures lA and lB
but showing the same fluid injector in a non-operating
position;
Figure 6 is a scrap plan view sectioned along
line VI-VI of Figure 5;
. ' 25 Figure 7 is an end view taken on line VIII-VIII
¦ of Figure 1 but with the change-over valve of the fluid
injector removed;
Figure 8 is a scrap sectioned plan view of a simil.-r
injector to that shown in the preceding figures but with an
3 alternative mechanical interlocking terminal;
Figures 9A, 9B and 9C together comprise a side
elevation, partly sectioned, of a second fluid injector
in a non-operating position;
Figures 10~ and lOB together comprise a sec.tionod
:1 35 plan view a].ong line X-X of Figure 9;
'1
1 155386
- 4
Figure 11 is an end view taken on line XI~XI of
Figure 9 but with the change-over valve of the fluid
injector removed;
Figures 12A and 12B together comprise a side
5 elevation, partly sectioned, of a third fluid injector
in a non-operating position;
Figures 13~ and 13B together comprise a sectioned
plan view along line XIII-XIII of Figure 12;
Figure 14 is a part sectioned plan view showing
10 modified male and female terminals for each of the
first and second fluid injectors when the injector is in
a non-operating position;
Figure 15 is a scrap view corresponding to Figure
15 but showing the male and female terminals interconnected;
15 and
Figure 16 is a scrap sectioned plan view showing a
male bridge mated with the female terminal of the first
or second fluid injector.
In the various figures, like references indicate
20 like parts.
Each of the fluid injectors to be described is
r primari]y intended for incorporation in an oil fuel
burner suitab]e for use in a fossil fired burner. Such
burners are arranged in the furnace walls of the boiler
' 25 for firing the boiler's fuel. Oil fuel is used as the
-~ prime fuel for firing burners, or as a secondary fuel for
igniting coal when that is the primary fuel, or in
¦ combinati~n with gas as an alternative primary fuel. The
j boiler would generate steam, and have land, marine or
30 other industrial applications.
; The fluid injector 1 shown in Figures 1 to 7 has
a considerable desree of similarity to that disclosed in
our United Kingdom patents Nos. 1~231,631 and 1~233~317
in that it includes an injection device 2 at its forward
35 cnd nnd a chanse-over valve 3 at its rearward end, both
I
.~
1 ~553~S
-- 5 --
i of which ~rc essentially constructed and operate in a
Z like manncr to their counterparts in those patents. Aq
such~ the injection device and change-over valve will
only bc described herein so far as it may be necessary
5 for the present injector to be understood, and attention
is directed to our aforementioned patents for a full
and complete disclosure which is herein incorporated
by reference.
Thus, the injection device 2 includes an
10 atomiser assembly ~ in which the fluid is mechanically
atomised during discharge supported in the forward
end of the injector barrel 5 which would normally be
suitably mounted in the wall of the boiler with its forward
end in an operating position inset from the boiler interior.
15 A tip valve 6 of the injection device i/s mounted for axial
sliding movement and is acted upon by a spring 7 the bias
!¦ Or which is sufficient to urge the tip valve forwardly
to close a discharge passage 8 in the atomiser a~sembly
when there iq no fluid supply to the injection device.
Normally~ fluid is continuously supplied to
the injection device 2 whenever the fluid injector is
conditioned to discharge the fluid or is shut-down. It
is a particular feature of the injector that when conditioned
for non-discharge, fluid is continuously circulated through
it to cool the forward region thereof and obviate the need
for the injector to be retracted away from the boiler interior.
, ._
Again, because of the continuous circulation, fuel cracking
and blockage in the injector is obviated, and there is no
necessity for cleaning between discharge operations.
,~ 30 When fluid is supplied to the injection device
2~ the position of the tip valve 6 is hydraulically
controlled by a pressure differential derived from the
supply flow to, and return flow from, the tip valve in
conjunction w~th the rolative areas thereof acted upon by
such flows. For that purpose, a contral tube 9 is mounted
I
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1 1~53~6
-- 5A --
within the barrel 5 to define an annular duct 10 between
itself and the barrel.
In a non-discharge condition of the injection
devicc 2, hot fluid under pressure from an external
oil fuel delivery line of an oil fuel delivery and return
circuit is caused to flow through a central duct within
the central tube 9 to and through the tip valve 6 and
into a chamber 4a in the atomiser assembly 4 ~rom which
the fluid will pass generally radially outwardly to
return through the annular duct 10 eventually to return
to an external oil fuel return line of the same circuit.
Such a flow has the result that the tip valve is urged
forwardly to close off the discharge passage 8 in the atomiser
assembly. The chamber 4a is behind the discharge passage
and its communication with the central tube and the
annular duct is not affected by the closure of the discharse
passage so ~hl:t even thouyh the lnjeotion
~' /
. _' ' ' /
:
. ~
~'
~ .
1 15538G
6 --
¦ device is conditioned for non-discharge, fluid can
continuously circulate within the central tube and
i barrel 5 past tho tip valve, a~ shown in Figure 2 in
which the blocked arrow~ ~lenote the Yupply flow and
the open arrows the return flow.
In a discharge condition of the injection
device 2, the direction of fluid flow just described
is reversed, as shown in Figure 4, so that the
supply flow is along the annular duct lO to the
injection device and the return flow from the
l injection device iQ through the central tube 9. ~he
;¦ reversed flow results in the tip valve 6 being urged
rearwardly to open the discharge passage 8 and so
effect fluid dischar$e therethrough, as illustrated.
The reversal of fluid flow within the central
tube 9 and the annular duct lO within the barrel 5 to
bring about the discharge and non-discharge conditions
, of the in~ection device 2 ig under the control of the
I change-over valve 3. ~he change-over valve might more
aptly be termed A flow reversing or flow diverting
valve since its valve spool 47 is, as will be later
described, linearly movable between positions in one
of which to divert fluid supplied from the oil supply
line along one flow path into the central tube and
to provide a return path from the annular duct back
~_ to the oil return line~ and in the other one of
which to divert fluid supplied from th~ oil supply
line along what wa~ the return path into the annular
duct and to provide a return path fro~n the central tube
(which previously served as ~aid one flow path) back
to the oil return line.
; From tlle above, it will be seell that the
change-over valve 3 i~, like t~e corre~ponding component
in tbe flui~ injector of our aforomentionod patcnt~,
~¦ 3~ oporable (in dependence on the position of its valve
,~
.~ .
11S53~5
-- 7 --
¦ spool 47) to condition the injector or fluid discharge
¦ or non-discharge, that conditioning being directly
¦ brougllt about by a reversible fluid pressure
differential the mode of which i~ ~etermined by the
i 5 direction of the fluid flow within the injector as
1 controlled by the change-over valve. ~loreover~ when
,I conditioning the fluid injector for non-discharge,
'¦ the change-over valve pe,rmits a continuous circulation
! of fluid within the injector from the oil supply back
i 10 to the oil return line when the injector iB
I coupled into a mains supply of fuel oil.
The present illjector of Figures 1 to 7 differs
, ~rom that of our aforementioned patents in that its
t change-over valve 3 is not located axially in line with
i; 15 the injector barrel 5. Xather, the change-over valve
is displaced downwardly of the barrel, although with
its longitudinal axis still parallel with that of the
barrel, and there is provided a fluid coupling device
~¦ 11 between the ehange-over valve and the rearward end
20 of the barrel.
,:
q T~e function of the fluid coupling device 11
¦ is to enable the barrel 5 with the central tube 9
¦ ~ therein to be retracted from the boiler wall to permit
~¦ inspection, servicing or replacing of the components
of the injection device 2 without disturbing the
~i mounting of the change-over ~alve 3 and the oil supply
a~d return line coupled thereto.
i The fluid coupling device 11 is sueh that
the oil ~upply and return line are automatically
30 isolated from the unit comprisins the injector barrel 5
l and the central tube 9 unless the barrel is fully inset
;~ to the correet operating position in the boiler wall
15 at which fluid disch~rge iB safely permissible.
~1 ~e~rnction of the bnrrel from the fully inset position
i I .
1 1~538~
.
-- 8 --
automatically causes the fluid coupling de~ice to
¦ discolmect the oil supply and return lines from
¦ the barrel ~nd central tube lmit. Accordingly, even
¦ though the change-over valve 3 mny be positioned to
condition the fluid injector for discharge, until the
barrel has been fully inset to the correct operating
po-~ition discharge will not take place. Indeed, should
at that time the change-~ver valve be positioned to
I condition the injector for non-discharge but to accept
a continuous circulation of fluid through itself, i.e.
through thff central tube and the annular duct 10 in
j the barrel, the continuous circulation will not take
¦ place either. In other words, the fluid coupling device
I will override the change-over valve with respect to
¦ 15 permitting flow to the barrel and central tube unit in
all positions of the barrel except the fully inset
~j operating one. When, and only when, the barrel i9 in
that position can the change-over valve function to
c~use either disch~rge from the injector or th~ injcctor
to have a non~discharge condition with continuous
circu]ation. It follows that if the barrcl was acciden-
tally or unintentionally withdrawn with the change-over
valve positioned to condition the injector for discharge,
i ' the fluid coupling device would function to fail safe
the injector. Normally, of course, the change-over
~~ valve would be positioned to condition the injector
for non-discharge before the barrel was withdrawn. It
should be mentioned that there is some degree of latitude
available in that there is a limited range of positions
of the barrel at which fluid discharge can be snfely
permitted, and the fluid coupling device will not
function to isolate the fluid supply and return lines
until the rearward limit of that po~tional range i~
. reached.
¦ 35 ~escribing now the mounting of the barr~l 5,
1 ~ 553~5
!
it is hous~d in a carrier tube 12 which carries at
¦ its forward end a flame stabiliser 13. The carrier
¦ tube is slidably supported in a centre carriage 14
i which may form part of a burner plate which, in turn,
! 5 forms part of the boiler wall 15, or which, as shown,
I may be a separate component bolted at 16 to the boiler
j wall. In any event, the centre carriage is made fast
j with the boiler wall~ and the carrier tube is fi~ed
in any desired position with respect to the boiler
j 10 wall by means of locating bolts carried by the centre
l carriage, one such bolt being referenced }7. The
¦ fully inset position of the barrel at which discharge
can be safely permitted is shown in Figures 2 and
4.
T~le fiuid coupling device 11 comprises a
pair of female and male terminals 19 and 20, respectively.
The female terminal i9 made fast with the carrier tube
12 and hence i8 prevented from movement since the carrier
tube i8 fixed to the boiler wall 15. The change-over
valve 3 is built on to the fixed female terminal. The
¦ male t'erminal i8 made fast with the barrel 5 and hence
is movable with it and with respect to the female-
' ' ' terminal. Carri'ed-by each terminal are two valve~
~ ' which are self-actuated to a closure position and
; 25 which are paired with the correspondin~ valves of'thé ''
other terminal such that when the terminals are
' separated upon the barrel being withdrawn, the valves
will au'tomatically move to a closed position with
re~pect to their own terminal. ~onversely, when the
! 30 barrel is fully inset and the terminals are engaged with one another, the paired valves will automatically
urge one another to an open position w~th respect to
r¦ their own terminal. It i~'that closing and opening
~l of the paired valves which isolates and commt~ica~es~
¦ ~5 respectivaly, th~ fluid 4upply and return lines
l .
.
1 1~53~;
-- 1 o
I through the change-ovor valve with respect to the
¦ barrel and central tube unit. l`he self-closure
valve~ are denotcd by reference~ 21 to 24.
~he male terminal 20 comprises a terminal
! 5 block 25 ~hich is affixed to the barrel 5 by means of
~ a collar26a welded thereto and screwed into the block.
j The valves 21, 22 are biased by springs 26 towards
'~ their seats 21a~ 22a in male collars 27 which are
- affixed to and project from the terminal block. A
duct 28 in the terminal block communicates the valve
-¦ 22 with the barrel annular duct 10, and a second duct
! 29 in the terminal block connects the other valve 21
with the interior of the central tube 9.
The female terminal 19 includes a terminal
plate 30 to which the housing 31 of the chan~e-over
valve 3 is made i~ltegral as by bolting at 32. Suitably
made fast with the terminal plate is a connecting
i block 33 having fast with its upper surface a pair o~
;, terminal blocks 34, 34a which have female collars 35
, 20 a press fit in the terminal plate. The terminal blocks
34, 34a are mounted on opposite sides of the carrier
~ tube 12 and are welded to it by which they together
,~1 with the terminal plate and the connecting block are
: made fast with the carrier tube. It is envisaged that
the pair of terminal block~, terminal plate and
~-~ connecting block could be a one-piece casting.
The female collars 35 are sized and arranged
~ to receivo the respective male collars 27 and maXe a
'1 seal therewith as by sealing rings 36. The valves
23, 2~ are mounted one in each of the terminal block~
3l~, 34a in chambers 37, 37a therein, each of which
communicates with the interior of the respective
female collar. Springs 38-bias these self-closure
I valvos toward their respective soat~ 23a, 24a in tho
¦ 35 chambers 37, 37a, the op~osite ends of which are
1 1553~6
1 1
¦ c108 ed by plugs 39.
I A duct 40 extends throu~h the terminal
block 3 , the connecting block 35 ~nd the terminal
plate 30 to interconnect the chamber 37 with a central
chamber 41 in the change-ovcr valve 3. A duct 41a
exten~s through the other terminal block 34a, the
connecting block and the terminal plate to înterconnect
the chamber 37a with a r~dially outer chamber 42 in the
change-ovcr valve.
The male terminal 20 is movable with respect
to thc fixed female terminal 19 to withdraw and inset
the barrel 5 by means of a handwheel 43 which is pinned
¦ at 4~ to a spindle 45 in turn journalled for rotation
¦ in the terminal block 25 but ~ade axially fast therein.
¦ 15 The forward end 46 of the spindle 45 projects from the
3 terminal block 25 and i9 screwthreaded to engage in a
¦ threaded bore 46a in the terminal plate 30 of the female
,¦ terminal 19. Thus~ rotation of the handwheel will screw
the spindle into or out of the terminal plate and cause
20 the terminal block 25 (together with the barrel and
~1 central tube unit) to move towards or away from the
rl terminal plate. The terminal block 25 is axially
~ guided during such movement by the sliding engagement
"¦ " of its male collars 27 with the female collars 35 of
25 the terminal blocks 34, 34a.
When the barrel 5 is fully inset in the boiler
`i wall 15 and hence is positioned as shown in ~igure 2,
the male collars 27 are fully en~aged in the female
collars 35. In moving to that position, the paired
¦ 30 valves 21, 23 and 22, 24 engage and urge each other
¦ against the bias of their respective springs 26, 38 out
of sealing contact with their respective seats 21a, 23a,
`¦ 22a, 24a . Thereby~ a firqt fluid flow patll in the
femnle terminAl 19 from the central chamber 41 in the
35 cha2lge-over valve 3 romprising the duct 40 nn<l the
1 15538~
- 12 _
j chamber 37 is communicated through the paired open
I valves 23~ 21 with the duct 29 in the male terminal 20
¦ and hence with the central tube 9. At the same time,
~¦ A second flow path in th0 female terminal from the
3 5 radially outer chamber 42 of the change-ovQr valve
'I comprising the duct 41a and the chamber 37a is
j communicated through the paired open valves 24~ 22
with the duct 28 in the ~ale terminal and hence with
the annular duct lO in the barrel 5.
When the spool 47 of the change-over valve 3
i9 positioned as shown in Figure 1, an inlet port 48
of the change-over valve which is permanently connected
to the oil supply line communicates with the
central chamber 41, and an outlet port 49 of the change-
15 over valve which is permanently connected to the oil
, return line communicate~ with the radially outer
! chamber.
Detailing more the structure of the chunge-
¦ over valve 3~ the spool 47 has lands 5O~ 51 slidable
within bushings 52, 53 mounted in the housing 31. The
central chamber 41 is defined w~thin the bushing 52,
and the radially outer chamber 42 between that bushing
and the terminal plate 3O. The spool is selectively
linearly movable into fluid discharge and non-discharg¢
25 positions by any suitable means, that illustrated
~- being a double acting pneumatic pi~ton/cylinder unit
54 whose cylinder i~ bolted at 55 to the rear end of
~ the bushing 53.
¦ Thereby, the positioning of the valve spool 47
shown in Figure 1 will cause, when the terminal~ 19, 20
. are engaged, fluid to flow from the fluid supply
line through the inlet port 48 and a radial hole 56
. in the bu~hing 52 into the central chamber 41~ From
there, the fluid flows through the first flow path in
35 the female terminal to and through the opened valve pair
I
!¦
1 15~38¢
- 13 -
¦ 23, 21 into the duct 29 in the male terminal and
¦ finally into the central tube 9, as indicated by the
blocked arrows in FigurQs 1 and 2. At the same time~
fluid can return through the barrel annular duct 20
via the duct 28 in the male terminal and the opened
valve pair 22, 24 into the second flow path in the
¦ male terminal and thence into the radially outer
chamber 42 of the change-over valve. From there,
the return fluid will flow through an axially
extending passage 57 in the bushing 52 into a chamber
¦ 58 between the bushings and along a passage 59 between
the bushing 53 and the valve spool to exit ahead of
~j the land 51 via a radial hole 60 in the same bushing
! into the outlet port 49 to return to the oil return
line. The return flow is denoted by the open arrows
~¦ in Figures 1 and 2.
Accordln~ly~ the flow dire¢tion ~ithin the
fluid in~ector is such that the injection device will
,~ be conditioned for non-discharge whilst at the same time
~ 20 fluid will circulate continuously from the oil supply
'~ line through the change-over valve 3 and the inter-
~,
connected female and male terminals 19, 20 to the
¦ central tube 9 and return from the annular duct 20 via
' those terminals to the change-over valve and thence to
, 25 the oil return line.
. ~~ At the same time, an alternative flow path is
, provided from the oil s~pply to the return line
directly through the valve spool 47 of the change-over
valve 3 by means of the inlet port 48, hole 56, central
cham~er 41, an axial passage 61 and radial holes 62 in
the spool, and radial holes 63 in the bushing 53 which
communicate with the outlet port 49, as indicated by the
open arrows in Figure 1.
j That direct flow path through the change-over
I 35 valve enables an additional circulation of fluid to be
i
1 1~53~6
introduccd into tho injector in its non-di~chArge
condition, as ln the injector of our aforementioned
~ patcnt~.
¦ An adjustment mechanism is provided whereby
dependent on the adjusted position of a back stop cover
64 screwed on to a sleeve 65 projecting rearwardly
from an cnd plate 66 of the air cylinder and within
which the valve spool ~7 is slidably supported, a back
~ stop 67 attached to the end of the valve spool may be
i 10 located so that a land 68 on the bushing 53 interferes
with fluid flowing from the radial holes 62 in the spool
to provide a selective range of fluid flows circulating
within the spool which may be preset at any desired
fluid flo~r within the constraints of the geometry of
th¢ change-over valve and the energy available for
p~ping fluid. Alternatively, the adjustment mechanism
may be omittecl so that fluid circulating through the
~¦ valve spool is fixed for given external pressure~
operatlng in the oil supply and return lineq.
The described direct fluid flow path through
the change-over valve spool 47 has another purpose,
and a particularly important one, in the present
injector, as will appear.
' When it is wished to inspect or service the
injection device 2, the handwheel 43 i8 rotated to
_.
urge the male terminal 20 rearwardly and so withdraw
I the barrel 5 inside the carrier tube 12. The new
r¦ position of the then "broken" fluid couplins d~vice 11
`~ is as shown in ~igures 5 and 6 with the change-over
.1 30 valve 3 rcmaining, of course, in the snme non discharge
position as before.
When the male terminal 20 is Yo ~ithdrawn, the
~ paired val~es 21, 23 and 22, 24 are free to clo~e again~t
j thoir respective seats under the bias of their spring~
1~ ~5 26 and 3a~ and so seal off the flow lines in the ma
~ ~,
1 15538G
5 -
i
I terminal and the female terminal 19. Thus, fluid
¦ ls seal.ed within the barrel and central tube unit.
I More imrJortantly, the valves in the female ter~inal
seal off the described first and second flow paths
! 5 therein at the terminal blocks 34, 34a, so that fluid
¦ cannot discharge from the female terminal even though
the change-over valve 3 continues to communicate the
oil supply line therewit~.
¦ The external conduit flow lines coupling the
1 10 change-over valve 3 with the oil mains line and
¦ constituting the oil supply and return lines can be
of considerable length. ~hen the male terminal 20 is
. retracted, fluid can continue to circulate from the
! ~ oil supply baclc to the return line directly through the
described alternative flow path through the valve spool
. l~7 oP the change-over valve, as indicated by the arrows
~¦ in Figure 5. Thus, the oil i~ kept in a liquid state~
and when the barrel 5 is replaced in the carrier tube
12 and in~,et again to the eorrect operating position
i~ 20 to open again the valve pairs 21, 23 and 22, 24, fluid
is able to flow without any appreciable delay from the
7 oil supply line to circulate within the central tube
9 and barrel annular duct 10 back to the return li~e
' to cool the injection device 2.
. 25 There are ~hort dead legs of fluid within
. the first and second flow paths in the female ter~inal
j 19 when the male terminal 20 is retracted, but the-q,e
~1 are kept liquid by heat eonduction through contact
.¦ with the heated oil circulating directly through the
;j 30 change-over valve.
¦ The direct flow path through the change-over
j valve from the oil supply to the return line whe~
`J the change-over valve is conditio~ling the in~ector for
~i non-dischargP i~ present, as said, in the injector of
our aroreLentloned patents~ but only for th- p~rpo~o Or
1 1553
,,
¦ enabling additional fluid to be circulated within
! the in~ctor. Since th~ change-o~er valve WAS built in
to the rcar end of the barrol~ it had to be withdrawn
with the barrol, and the supply flow needed to be shut
5 off at that time. Accordingly, there was no reason to
suppose that the direct fluid flow path could ~erve the
present purpose, and it was only when we introduced the
fluid coupling device 11 into the injector that we
¦ realised, unexpectedly, the extra function ~hich that
flow path could serve and the beneficial effect which
-¦ resulted.
¦ Without that direct flow path, there could
I exist dead legR of oil within the lengthy conduits of
the oil supply and return lines which would tend to
solidify dependin~ on the "down time" of the injector
for maintenance and which would take some timo after
inRet of the barrel to liquefy durins which time the
" in~ector device, in being starved of circulating fluid,
could become overheated and damaged.
When the barrel 5 is fully insét in the boiler
~ wall 15 and the injector is to be conditioned for fluid
; discharge, the change-over valve spool 47 is moved to
the position shown in Fi$ure 3. Thereby~ fluid will
flow from the oil supply line through the inlet port 48
~; 25 of the change-over valve and via the radial hole 56
~ into a passage 68 behind the spool land 50 and thence
through the chamber 58 in the reverse direction through
the passage 57 to emerge in the radially outer chamber
42. From there, the fluid flows upwardly in the duct
30 41a in the female terminal 19 to pass via the opened
valve pair 24, 22 to the duct 28 of the male terminal
~ 20 and thence into the barrel annular duct 10. ~he
] supply flow of fluid is indicated by the solid arrowY
in Fisure~ 3 and 4.
Fluid ean ret~lrn irom the ccntr~l tube 9
. I .
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1 ~553~
- 17 -
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i through the duct 29 in the male terminal 20 and via
the opencd valvc pair 21, 23 into the duct 40 in the
female terminal 19 to pass downwardly into the centr~l
chamber 4~ of the change-over valve 3 and through the
passage 61 in the spool 47 to flow via the radial
holes 62 through the hole 60 in the bushing 53 back
into the outlet port 1~9 to be returned into the oil
return line. The return flow is denoted by the open
arrows in Figures 3 and 4.
l 10 The described flow direction i8 such as to
;l condition the tip valve 6 to open so that fluid will
-I discharge through the discharge pa~sage 8 as shown in
,~ Figure 4.
As described~ there is a spill back of fluid
from the injection device 2 along the central tube 9
in that not all the fluid which i~ supplied to the
injection device i8 discharged. An additional adju~t-
ment is provided whereby dependent upon the position of
adjustment nuts 69 on the rear end of the valve spool
' 20 47, a land 70 on the bushing 53 is allowed to interfere
!; with fluid spilling back from the radial holes 62 via
the bushing hole 60 into the outlet port 49, with the
re~ult that the proportion of fluid which is returned
' to the oil return line may be selectively adjusted
to zero to provide a range of discharge flows for given
t`~--_ external prcssures operating in the fluid delive~ and
return lines. Alternatively, the adjustmen* nuts ma~
be omitt0d so that fluid discharge from the injector i8
fixed for ~uch given external pressure~.
To permit an adequate fluid flow through the
opened vnlve pairs 21, 23 and 22, 24 when the male 20
and female 19 terminals are engagcd, the length of
the aperture formed between each such vnlvc and itc
seat mu~t be suitably si7.ed. In consequence, when the
male terminal 20 i8 Wi thdrawn together with the barrel
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and central tube unit by operation of the handwheel 43,
¦ fluid flow continues pa~t the valve pairs for part of
¦ the travel of the male terminal. Thus, some tolerance
must be provided to accommodate discharge through the
¦ 5 injection device 2 in the course of retraction of the
¦ barrel, and tllis tolerance must be provided in defining,I the allowable position of the injector device in
relation to the carrier ,tube 12 for discharge purposes.
Additional tolerance must be provided so that a~ the
! lo barrel is withdrawn and the male terminal slidingly
I disengages from the female termin~l, then for that
length of travel of the male terminal that fluid flow
~¦ past the valve pairs continues, the male collars 27
I must be sealed within the female collars 35 as is
15 achieved by the seals 36.
With the self actuating to closure valves 21
and 23 of thc m~le terminal 20 in the above described
injector, no means i~ provided for relieving the
, preY~ure or venting the fluid within the ir~jector
20 barrel when withdrawn. Such means is provided in
the alternative male terminal 20 ahown in Figure 8
, which shows, instead of spring bia~ed valves self
uctuated to closure, self vented and fixed male valves
71 providing axial fluid flow holes 72 to the interior
25 of the male collars 27 which serve the
same purpose as the self actuated valves.
, Referring now to Figures 9 to ll, the fluid
injector lA shown therein is generally similar to the
in~ector 1 of Figures 1 to 8 as modified to incorporate
~ 30 the vented male val~es 71 and functions in the same wny.
I The present injector, i4 modified~ to enable tho u~e
oP a second fluid to regulate discharse. For a full
disclosure of the injector device 2A and the change-ovcr
3 valve 3 of the in~ector lA, attention ~ drawn to our
! ~5 United Kinsdom patent No. 1,497,271 tlle subject matter
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1 1~53~
-- 19 --
I of which is incorporated herein by reference.
¦ The injector lA will only be de~crlbed herein
f insofar a~ the principal differonces between it and the
injector 1 are concerned. Thu~ the second fluid, which
5 could be steam, is supplied to the injector device 2A
along an annular duct 73 defined between the barrel 5
~ and an encompnssing outer tube 74 which is made fast
¦ with the barrel and centr,al tube unit and which is al~o
i made fast with the male terminal 20. A steam supply
10 circuit is connected via an inlet port 75 with the female
terminal 19 so that when the two terminals are separated
upon withdrawal of the injector device, means must be
I provided to isolate that steam supply ~rom the broken
¦ fluid coupling device 11 so thnt it cannot escape from
15 thc female terminal.
To that end, the steam inlet port 75 is
) providod in the connecting block 33 and communicntes vi~
¦ a duct 76 therein with a chamber 37b in a third
~ terminal block 34b forming a part of the integral block
4 20 and plate structure of the female terminal 20. A third
i spring biased self closure valve (not shown) is arranged
in the chamber 37b to seal against its seat in a female
} collar when the male terminal 20 is separated from the
~ female terminal. A third self venting and fixed male
i-f 25 valve 71a is arranged ff~O that its male collar 27 will
¦- enter that female collar (in the same manner as the
~¦ ~ other t~o male valves in their respective female collars)
when the male terminal i4 connected with the female
1 terminal to open the third spring biased valve to permit
30 steam to escape through that male valve via a duct 77
in a sleeve 78 fast with the terminal block 25 and
into the second annular duct 73.
! The fluid injector 18 shown in ~igures 12 and
f 13 i~ of the pressure jet type which is mechanically
35 atomised and incorporntes a fluid atomiser assembly 4A
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and an operating valve 3A. In this embodiment~ either
oil fucl is passed down the central tubo 9 or thc tube
and the atomiser assembly is ~urged with a cooling
, fluid. There is no return path from the ntomiser aAsembly
5 and hence only one -~et of valve mean~ sealing the
supplied fluid ~ithin the female terminal 19 when the
male terminal 20 is withdrawn to retract the atomiser
assembly is necessary.
Coolin~ fluid is supplied to the operating
valve 3~ throush a port 79 ard oil from an oil supply
¦ line through a port 80. In the position of the
spool 81 of the operating valve shown in ~igure 12,
cooling fluid can flow into a chamber 82 in which the
i spool is reciprocated as by a double acting pneumatic
piston/cylinder unit 54 and via a passageway 83 in the
~pool into a duct 8~ in the female terminal and thence
into a chamber 37 hou~ins a ~pring biased closure valve
23. Since the male terminal is shown withdrawn, the
valve 23 i5 closed to seal off escape of the cooling
fluid from that chamber 37. In the same position of the
¦ valve spool, there is a direct flow path from the oil
9 supply line to the oil return line via the port 80
and passageways 85 through the bushing o6 and around
the spool into an oil outlet port 87. Hence oil can
circulate continuously between the lines and so not
~ be prone to solidifying. ~hen the spool i~ retracted,
oil can flow from the port 80 into the duct 84 but again
~`~ is prevented by the closed valve from escaping from the
-~ female terminal~
-~hen the handwheel l~3 is rotated to screw its
threaded ~pindle end 1l6 into the terminal plate 30 and
~o inset the atomiser a~sembly 44 into the boiler wall,
the male co]lar 27 will ¢nter the fem~le collar 35 and
cause ~ts self vented and fixcd male valve 71 to urge
J 35 the valve 23 open so that fluid, whether it he oil or
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_ 21 -
I purging cooling fluid as the case may be depending
! on the position of the valve spool 81, is caused to
flow from the chamber 37 past the opened valve 23 into
the male collar 27 and thence via the duct 29 into
5 the central tube 9 down towards the atomiser assembly 4A.
~g mentioned,when the male terminal 20 is retracted
¦ there are short dead legs of fluid within the first and
¦ second flow paths in the female terminal 19 of the first
3 and second fluid injectors 1 and lA. Means may be provided
! lo for intercommunicating those first and second flow paths to
obviate those dead legs upon retraction of the male terminal
20 so that fluid delivered from the oil supply line is able
to circulate continuously through them back into the oil
return line as well as circulating directly through the
15 valve spool 47 of the change-over valve 3.
In one such arrangement shown in Figures 14 and 15,
the first and second flow paths are intercommunicated in the
female terminal 19 itself when the male terminal 20 i~
retracted. Thus~ as ~hown in Figure 1l~, the ducts 40, l~1a
20 are interconnected in the female terminal 19 by passages
88~ 89 i~suing at one end respectively from each and
; ~ at the opposite end into a valve chamber 90.. A valve
member 91 is biased by a spring 92 off its seat 93 in the
; valve chamber 90 when the male terminal 20 is retracted
~ 25 so that the passages 88, 89 intercommunicate throu~h the valve
; chamber. ~ence, fluid can flow from the oil supply line into
the chanse-over valve 3 and thence along the duct 40,
0 passage 88, valve chamber 90, passage 89 and duct 41a back
-~ into the change-over valve to exit into the oil return line.
The valve member 91 extends into a recess 94 in the
female terminal 19 with the spring 92 located between the
base of the recess and the valve head 95. Sealing means
96 are providcd around the stem of the valve member 91
to prevcnt escape of fluid from ~he female terminal 19 when
the ducts 40~ 41a are intcrconnected. The male terminal
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- 22
20 carries a plug 97 sized to enter thc recess 94, when
, thc malc tcrminal 20 is interconnccted with the female
i terlninal 19 t~ inset the barrel 5 at which time it will
on~age t]lC valve head 95 to urge the valve mem'ber 91 against
1 5 the bia~ of the spring~ 92 and into sealing engagement with its
! valve seat 93 (as shown in Fisure 15). Thereby, the passages
88 and 89 are isolated from each other, and the resulting
I flow paths in the female terminal are as in the first and
¦ second fluid injectors 1 and lA.
In an alternative arrangement shown in Figure 16
for intercommunicating the first and second flow paths
in the female terminal 19 when the male terminal 20 is
retracted, the interconnection is through a male terminal
in the form of a bridge 20A.
The bridge 20A is generally similar to the male
terminal 20 but lacks the ducts 28 and 29. Instead, a
duct 98 in the terminal block 25 direct intercosnmunicates
the'valveq 21~22. Moreover, the barrel 5 iq replaced by a
! pilot tube 99 closed at its forward end. Whilst the valves
21, 22 are shown as self-actuating to closure they could
alternatively be self venting male valves as in Figure 8.
When the male terminal 20 has been retracted to
withdraw the barrel to enable inspection or servicing of
the injection device 2, it is replaced by the male
bridge 20A which couples with the female terminal 19 in
the same manner as the male terminal 20. When so coupled,
_ the valves 21, 22 engage the valves 23, 24 respectively so
that the paired valves open. The result is that the ducts
40, 41a in the female terminal 19 are connected with each
3 other through the paired opened valves 23, 21~the duct
i 98 in the male bridge 20A and the paired opened valves 24,22.
¦ Accordingly, fluid delivered from t~e oil supply line to
tho chansc-over valve 3 can circulate through the female
¦ tcrminal 19 via the male bridgc 20A back into the femalc
il 35 tcrminal to return via the change-over valve into the oil
1 rcl:urn line.
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1 1553~6
- 23 -
¦ ~t will be noted that in each of the fluid¦ injoctors as disclosed herein, when the male and female
torminal~ are interconnected, the injection device
together ~ th the fluid coupling device and flow control
valve comprise a composite structure having flow paths
internal to that structure tthereby obviating the need
for external connecting tubes or pipes between the various
components of that structure which could be prone to
leakage where connected to the individual components) along
which oil can be routed by the flow control valve from the
¦ fluid delivery line to the injection device. ~oreover,
in the case of the tip valve embodiments providing for a
return flow of oil, such flow will also be routed by the
flow control valve back to the fluid return line from the
injection devico via the fluid coupling device along such
internal flow paths.
~ n oil burner incorporating any of the fluid
injectors as described would also have an air register
to provide the combustion air, valves to regulate and
shut off the air and fuel supplies and an igniter to
initiate combus~ion.
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