Note: Descriptions are shown in the official language in which they were submitted.
1 157780
This invention relates to the purification of gases and
in particular of waste gases. This invention is especially con-
cerned with at least reducing the quantity of pollutants such as
carbon monoxide and smoke in gases emitted from internal com~
bustion engines.
Gases from internal combustion engines often contain
finely divided particles of hydrocarbons and/or carbon and/or
other solid matter which emerge in the form of smoke. The smoke
from a diesel engine, for example, is composed of solid/liquid
particles, solid chain aggregates in which essentially spherical
particles of between 100-800~ diameter, link up together liquid
sulphates, liquid hydrocarbons and gaseous hydrocarbons. The
solid/liquid particles generally comprise carbon particles with
adsorbed liquid hydrocarbons and the solid chain aggregates are
generally composed of high molecular weight organic compounds
and/or inorganic sulphates.
Three different types of smoke are commonly observed
issuing from diesel engine exhaust pipes. These are "white smoke"
"black smoke" and "blue smoke". White smoke is produced when the
engine first starts up and results from the condensation of water
vapor on to particles contained in the exhaust gas so that a fine
mist is formed. Black smoke is produced when the engine has
warmed up and contains a relatively high proportion of carbon
particles. In blue smoke there is some carbon with a relatively
high proportion of gaseous hydrocarbons such as aldehydes.
1 157780
Throughout the remainder of this specification the
particles referred to above will be described as "smoke forming
particles". About 90% of these smoke forming particles have maxi-
mum dimensions of less than one micron which is within the
respirable particle size and the maximum dimension of the remain-
ing 10% of these smoke forming particles is less than four
microns.
Other undesirable components present in exhaust gases
are noxious gases such as carbon monoxide and hydrocarbons. In
this specification the word "pollutants" is to be taken to mean
smoke forming particles and noxious gases.
Catalytic oxidation of carbon particles takes place at
about 400C whereas the normal temperature of combustion of these
particles is 700-800C. For hydrocarbon particles catalytic oxi-
dation will take place at temperatures about 200C. The effect
of a catalyst on the temperature at which catalytic oxidation of
particulates entrained in the exhaust gas stream of a diesel
engine took place were studied. A number of sample catalysts
were prepared. The catalysts comprised a substrate fabricated
from 310 stainless steel wire of diameter 0.010 inch, rolled down
to ribbon 0.004 inch thick, a layer of alumina and a layer of one
or more platinum group metal(s) at a loading of 2.46 mg/g of
alumina. A portion of coated wire was cut from a catalyst and
heated gradually raising the temperature together with particu-
late matter, collected from the exhaust gas stream of a diesel
engine, in the sample pan of a differential scanning colorimeter
(a DSC) in an atmosphere of 1% oxygen in argon. Samples of the
1 157780
atmosphere above the sample pan were taken via a heated capillary
tube to a mass spectrometer. Four mass numbers were traced:
carbon monoxide (44), double charged argon (20), oxygen (32) and
water (18) or nitrogen and carbon monoxide (28). The temperature
at which the differential plot of the DSC peaked was taken to be
the temperature at which combustion of the particulates took
place. This temperature can be referred to as the "light-off~
temperature. The results are given below:
Alumina Loading CatalYtic metal(s) Light-off
(g/g of wire) temperature (C)
0.33 5.7% Rh 94.3% Pt 235
0.28 67% Pt 33~ Pd 207
0.30 Pd 265
0.28 Pt 220
The light-off temperature of particulates from the exhaust gas
stream of a diesel engine, 207-265C, is csnsiderably lower than
the temperature for combustion to take place when no catalyst is
present. Since the presence of a catalyst enables oxidation of
the smoke for~ing particles in a gas to take place at a lower
temperature than the normal temperature at which combustion takes
place, little or no heating of the exhaust gas from an internal
combustion engine should be required when it is desired to effect
the catalytic oxidation of any smoke forming particles in the
gas. For example, a diesel engine runs at about 400C when
operating at medium to full power so that no preheating of the
exhaust gas issuing from the diesel engine would be required
before passing the said exhaust gas over a catalyst to remove
the smoke.
1 157780
forming particles from the gas by catalytic oxidation, provided
the catalyst is close to the engine.
Internal combustion engines are often used in areas
where there are stringent regulations on their use such as in
mines. Diesel engines which are to be used in a NCB mine are
modified to comply with regulations controlling the use of diesel
machinery in mines. The engine is surrounded by a water jacket
so that the temperature of any exterior part of the engine which
comes into contact with the atmosphere is less than 120C. The
exhaust gas of the engine is passed through a water conditioner
and flame traps before finally being emitted to the atmosphere.
The water conditioner may be a container of the water through
which the exhaust gas is bubbled or water may be sprayed into the
stream of exhaust gas. Any chamber containing a catalyst, for
treating the exhaust gas, will have to comply with regulations
but still keep the temperature of the exhaust gas up to enable
catalytic removal of the pollutants to take place.
An object of the present invention is to at least reduce
the quantity of the smoke contained in exhaust gas by effecting
catalytic oxidation of smoke forming particles in the gas.
A further object of the present invention is to reduce
the quantity of noxious gases and particulates present in the
exhaust gas from an internal combustion engine.
-- 3 --
1 1~7780
Another ob~ect of the present invention is to provide a modlfied
diesel or petrol driven internal co~bustion engine such that a considerably
reduced quantity of noxious gases and particulates is produced.
In accordance with the present invention there is provlded a diesel
engine comprising one or more cylinders which can generate exhaust gas
containing carbon particles when the engine is in operation, each cylinder
having an exhaust port for discharglng the exhaust gas, and the engine is
provided with an exhaust pipe for venting the exhaust gas to atmosphere and
in co~bination with the engine an apparatus suitable for oxidising the
carbon particles wherein
(a) the apparatus comprises a chamber and means for cooling the
chamber and the chamber ha~ at least one entry port in communication with an
exhaust port and an exlt port ln communlcatlon with the exhaust plpe so that
exhaust gas can pass from the exhaust port through the chamber and lnto the
exhaust pipe,
(b) the chamber contains an interstitial catalyst system comprising
a catalytic metal, a layer of refractory metal oxide and a substrate made
from filamentary metallic material in a knitted or woven form, the catalyst
being disposed on or throughout the layer of refractory metal oxide which in
turn 1~ tlsposed on the surface of the ~ubstrate;
(c) the substrate i8 mounted within the chamber spaced from the
inner walls of the chamber so as to create an outer passageway, and is
shaped so as to define a central passageway within the substrate,
(d) wherein one of the passageways communicates with the entry port
or ports and the other conununicates with the exit port and the substrate is
positioned so that substantially all the exhaust gas discharged from the or
each cylinder ls caused to pass through one passageway, then through the
interstitial catalyst system and then thr,~gh the other passageway, and
- 4 -
1 157780
(e) the outer and central passageways and the substrate are aligned
relative to the entry port or ports such that exhaust gas passing through
the chamber is caused to flow in a direction transverse to the entry port or
ports during a portion of lts pa~sage through the chamber thereby increasing
turhulence within the interstitial catalyst system.
The catalytic metal may be selected from the group consisting of
Ru, Rh, Pd, Ir, Pt, Fe, Co, Ni, V, Cr, Mo, W, Y, Ce and alloys and
intermetallic compounds containing at least 20Z by weight of one or more of
these metals disposed upon the surface of or throughout the refractory metal
oxide washcoat layer.
The refractory metal oxide washcoat layer preferably contains in
the form of their oxides one or more members of the group consisting of Mg,
Ca, Sr, Ba, Sc, Y, the lanthanides, Ti, Zr, Hf, Th, V, Cr, Mn, Co, Ni, B,
Al, Si and Sn.
A preferred layer material is A12O3 and alumina hydrates but
stabilising oxideæ such as BaO and oxides promoting catalytic activity such
a8 TiO2, ZrO2, HfO2, ThO2, Cr2O3 and~iO may also be present.
The structure of knitted or woven form used as the substrate makes
the exhaust gas flow through the catalyst turbulent. Metals or alloys used
in the fabrication of the substrate are preterably oxidation resistant and
should be thermally stable up to at least 600C.
Suitable base metal alloys are nickel and chromium alloys having an
aggregate Ni plus Cr content greater than 20% by weight and alloys of iron
including at least one of the elements chromium (3-40) wt %, aluminum
(1-10) wt %, cobalt (trace-5) wt %, nickel (trace-72) wt % and carbon
(trace-0.5) wt ~. Such substrates are described ln German DOS 2450664.
Other examples of base metal alloys capable of withstandlng the
rigorous conditions required are iron-alumlnium-chromium alloys which may
I 1577~Q
also contain yttrium. The latter alloys may contain 0.5-12 wt % Al,
0.1-3.0 wt % Y, 0-20 wt ~ Cr and balance Fe. These are described in
United States Patent No. 3298826. Another range of Fe-Cr-Al-Y alloys
contain 0.5-4 wt X Al, 0.5-3.0 wt X Y, 20.0-95 wt ~ Cr and balance Fe
and these are described in United States Patent No. 3027252.
Alternatively the base metal alloys may have less corrosion
resistance, e.g., mild steel, but with a protective coating composition
covering the surface of the substrate as described in our co-pending
Britlsh Patent Application No. GB 2,013 517A published 15 August 1979,
corresponding to Canadian Patent 1,128,031.
Where wlre is used as substrate lts thlckness is preferably
between 0.0254 and 0.508 mm dlameter and more preferably between 0.254 and
0.305 mm diameter.
Specific embodiments of the inventlon will now be described wlth
reference to the accompany drawings in which: `
Figure 1 and 2 show catalytlc systems ad~acent the exhaust ports of
cylinders of an internal combustion engine;
Figure 3 is a diagra~matic repre~entation of an apparatus
containing a catalyst system shown in section;
Figure 3A is a diagrammatic representation of an alternative
apparatus containing a catalyst system shown in section;
Figure 4 is a perspective view of a spacer unit suitable for use in
the apparatus shown in Figure 3;
Figure 5, on the same sheet as Figure 1, ls a perspective view
of an alternative spacer unit suLtable for use In the apparatus shown in
Figure 3A;
Figure h to 45 are graphs illustrating the performance of the
catalyst systems described; and
~ - h -
1 157780
Figure 46 to 49 are histograms illustratil~ the performance of
catatyst systems comprising catalysts A or B as described in Example 2.
In Figure 1, the outer wall, 7, of a catalyst chamber has openings,
10 and 11, which are adjacent to and continuous with the exhaust ports of
the cylinders of the engine and one exit, 12, ad~acent to the exhaust pipe,
13. Catalysts, 1, 2, 8 and 9 are positioned as shown. The catalyst chamber
has an inner wall, 5 and two outer walls, 6 and 7, with an air gap between
the walls S and 6 and the gaps between 6 and 7 filled with circulating
water. The water is provided from the water ~acket surrounding the engine.
The
....
~ _ f,~ _
1 15778~
exhaust gas flow is generally indicated by the labelled arrows
Fl, F2, F3, F4, F5 and F6. Exhaust gas flows from the cylinders,
through the exhaust ports and through into the openings, 10 and
11, into the chamber and makes contact with catalysts 1 or 2 and
then catalyst 8 and possibly catalyst 9 before passing through
the opening, 12, to the exhaust pipe.
The substrate may be a monolith or a structure of wire.
If a wire substrate is used one unit for each catalyst may be
used or a number of small units linked together.
In Figure 2, the catalyst chamber has openings, 10 and
11, adjacent to and continuous with the exhaust ports of the
cylinders and one exit, 12, adjacent to the exhaust pipe, 13.
Between the inner wall, 25, and outer wall, 27, of the catalyst
chamber, water from the cooling water jacket of the engine circu-
lates. An inner chamber, 24, containing two catalysts, 1 and 2,
is arranged in the catalyst chamber as shown in Figure 2 such
that the exhaust gas on entering the catalyst chamber has to pass
through an inner chamber, 24, and makes contact with the cata-
lysts before leaving the chamber and entering the exhaust pipe.
Part of the inner chamber, 29, is perforated with holes or slots
to allow the exhaust gas therein to pass from the inner chamber
to the catalyst chamber and thence to the exhaust pipe. Exhaust
gas entering the catalyst chamber at opening, 10, flows through
the chamber as indicated by the labelled arrows F21, F23, F25,
F27, F28 and F31 while gas entering at the other opening, 11,
flows through as indicated by the labelled arrows F22, F24, F26,
F29, F30 and F31
7 --
1 157780
The support may be a monolith or fabricated from metal-
lic wire. The two catalysts are positioned in the catalyst
chamber as shown in Figure 2 so that approximately the same
amount of exhaust gas passes through each catalyst, the exhaust
gas from one cylinder passing through one catalyst.
An embodiment of the invention is depicted in Figure 3,
in which one or more catalysts with optional spools are utilised.
The catalyst chamber has openings, 50 and 51, adjacent to and con-
tinuous with the exhaust ports of the cylinders and one exit, 52,
adjacent to the exhaust pipe, 53. The catalysts, 41, 42 and 43,
comprising a support, a washcoat layer and a catalyst metal, are
disposed so that the exhaust gas on entering the catalyst chamber
is compelled to pass through the interstices of at least one
catalyst before leaving the chamber and entering the exhaust pipe.
The exhaust gas flows through the chamber as indicated by the
labelled arrows, F41, F42~ F43~ F44~ F4s~ F46~ F47~ F48~ 49~
F50, F51, F52, F53~ F54~ F55 and F56- The exhaust gas enters the
catalyst chamber through a sleeve arrangement, 45, which is set
into the chamber, and is deflected by a spool, 47, before passing
through the catalyst.
In this embodiment the substrate for the catalyst is
preferably of knitted wire which may be unitary or in sections.
Sections, for example, of doughnut configuration, are normally
linked together before being placed in the chamber. Annular
discs, 48, may be used to secure the catalyst to the walls of the
chamber. In the centre of catalysts, there is a spacer unit, 45,
which supports the catalysts and spools and forms an exit tube
8 --
1 1577~
through which the exhaust gas passes to enter the exhaust pipe.
The spools are not essential and one long catalyst may be used.
Figure 4 depicts one form of a spacer unit in which a
series of 5 rigid bars 100-500 running the length of the chamber
are used. These are maintained in fixed spatial relationship to
one another, thus holding the supported catalyst rigidly in place
within the chamber, by the use of spacing plates 600. The spac-
ing plates in pairs connect three of the five bars and are usual-
ly at right angles to each other thus being disposed along a dia-
meter of the central cylindrical exit tube. Two or more pairs ofspacing plates may be used and they are usually positioned at
regular intervals in the length of the chamber. Alternatively
the spacing plates may be used instead of rods where they would
be continuous throughout the length of the chamber as shown in
Figure 5. Rods and spacing plates need to be constructed of a
material resistant to oxidation up to 800 C.
A further embodiment will be described with reference to
Figure 3A. The catalyst chamber has openings 82 and 83 adjacent
to and continuous with the exhaust ports of the cylinders and one
exit 84 adjacent to the exhaust pipe. Water from the cooling
water jacket of the engine circulates between the inner wall 81
and the outer wall 80 of the catalyst chamber. The catalyst 85
comprising a support, a washcoat layer and a catalytic metal is
so disposed that the exhaust gas has to flow through the catalyst
before leaving the chamber. The catalyst is disposed in the
chamber using spacing plates 86 as described above. One end of
the spacing plates 89 is fixed to the chamber wall 81 and a disc
1 1577gO
or metal plate 90 is attached to the other end of the spacing
plates to ensure that no exhaust gas can leave the chamber with-
out passing through the catalyst. The exhaust gas flows into the
chamber through the openings 82 and 83 down through sleeves 87
and 88 and through intermediate chambers 92 and 93 into the
inner space 91 provided by the spacing plates 86. The exhaust
gas then flows through the catalyst outwards and then through
~0
- 9a -
1 1577~
the exit 84. The flow of the exhaust gas is indicated by the
labelled arrows F60-F79. The intermediate chambers 92 and 93
comprise a hollow cylinder with integral end flanges having sub-
stantially centrally positioned holes to allow the spacing plates
86 to pass through and a sleeve, either 87 or 88, is fitted
radially into the cylinder wall such that the joint is gas tight.
The support for the catalyst is preferably of knitted
wire which may be made up into four sections or three units. If
the support is in sections, e.g. of doughnut configuration, these
are normally linked together before the support is placed in the
chamber.
A Perkins 4.236 diesel engine, a low emissions diesel
engine, modified for mine use was used to demonstrate the results
obtained in operation.
Example 1
A catalyst chamber as outlined in the first embodiment,
Figure 1, was fitted to the engine. The substrate W2S a monolith
of cell density 400 cell/sq. in. made from an alloy of the
following composition:-
% wt
Cr 15
Al 4
Y 0.3
Fe balance
-- 10 --
~ 1 157780
~ -- 11 -
A washcoa~ Or alumina stabilised with ceria at a loading of
1.5 g~cu ft was applied. The cat~lytic metal layer comprising Pt and Pd
in the ratio of ~:1 was applied at a loading of 80 g~cu ft. The variation
of the amount of hydrocarbons, carbon monoxide, nitrogen oxides ~nd
particulates, presen~ in the exhaust gas, with the load ~f the diesel
engine as brake mean effective pressure was measured at 1,0QO rpm and
2200 rpm. The results of these measurements are given in graphical form
in the attached figures 5-21. Table 1 below gives the deta-ls of the
measurements taken and tne figures giving the results.
~ 10 Table 1
) Speed of Figure
Pollutant in exhaust gas measured engine in
rpm
Carbon monoxide. CO, in ppm 1,000 6
" 1,400 7
1,800 8
~ 2,200 9
Hydrocarbons, HC, in ppm 1,000 10
1~ 1,400 11
n 1,800 12
., 2,200 t3
Nitrogen oxides, NOx, in ppm 1,0G0 1~
~, 1.400 15
- - - 1,800 t~
- 2,200 17
Particulates in g/hr 1,000 18
~ 1,400 19
,. 1,800 20
2,200 ~1
... . .. . . .. . . ..
1 157780
The two lines show the difference between the pollutants
present in the exhaust gas when no catalyst cha~ber is used,
('baseline'), represented in the figures by X X ~ , and
after the exhaust gas has passed through a catalyst chamber,
represented by the figures by _ . A high sulphur
containing fuel with 0.7% sulphur was the fuel for the engine.
A further set of results were obtained using the catalyst
fitted to the engine as described above. The results were ob-
tained with the engine running at 1,400 rpm for Figures 36, 37,
38, 39 and 40 and at 2,200 rpm for Figures 41, 42, 43, 44 and 45.
Example 2
Further experiments were carried out using a catalyst
chamber as described in Figure 3. A knitted mesh substrate was
fabricated from wire of diameter 10 thou". Two catalysts were
prepared. The substrate for catalyst A was fabricated from wire
of an alloy of the following composition.
% wt
Cr 15
Al 4
Y 0.3
Fe balance
The washcoat of alumina stablished with ceria was present at a
loading of 0.13 g/g of wire substrate. The catalytic metal layer
comprising 7~% Hr, 92~% Pt was applied at a loading of 80 g/cu ft.
Catalyst B had a washcoat of alumina at a loading of 0.2 g/g of
wire onto which was applied the catalytic metal layer of 5~% Rh,
94.5% Pt with a loading of 7 g of catalytic metal over the three
- 12 -
1 157780
catalyst units. The substrate was fabricated from 310 stainless
steel which was treated with a protective coating composition as
described in our co-pending British Patent Application No.
GB 2,013 517A published August 15, 1979.
- 12a -
I 157780
~ 13 ~
The variation o~ the amount of hydrocarbo.ls, carbon monoxide,
nitrogen oxides and particulates, present in the exhaust gas, with the Load
of the .~.iesel engint as brake ~ean effective pressure was meas~red at
11~(!0 rpm and 2200 rpm for catalyst A. The fuci ~Ised ir. the engine ~as a
high sulphur fuel containing 0.7% sulphur. Th~ variation of the partic~la,.os
~resent in the exhaust gas with the power of the engine was measured usir.g
a low sulphur fuel containing 0.07~ sulphur in the engine with catalyst
A in the catalyst chamber.
Using catalyst B the variation of the particulates ~ith the po-.~er
o~ the engine was me~.sured with the engine running on h-gh and low s-~lphur
fuels.
~ The results are given in graphical form in the a~tached
Figures 22-35. Table 2 below gives the details of the mea~urements taken.
Table 2
~pe~d of
Pollutant in exhaust gas measured Catalyst engine in Fuel . Fig~-e
rpm
.
Hydrocarbons HC in ppm A 1,~00Hi~h S 22
Carbon monoxide C0 in ppm A 1,400 " 23
Particulates in g/hr A 1,400 " 24
Nitrogen oxides in p~m A 1,400 " 25
Hydrocarbons HC in ppm A 2,200 " 2~
Carbon monoxid~ C0 in ppm A 2,200 " 27
Particulates in g/hr A 2,200 " 28
Nitrogen oxides in ppm A 2,200 " 29
Particulates in g/hr A 1,400 Lo~ S 30
Particulates in g/hr A 2,200 " 31
B 1, 4 00Low and 32
high S
" . B 2,200" 33
B 1, 4 00High ~ 34
. " B 2,2Q0 " 35
I 157780
1~
The two iines in Figures 22-31 sho~ the difference between the
pollutants present in the exhaust gas when no catalyst chamber is used,
'ba.~eline', and after the exhaust gac has passed through a catalyst
chamber.
y~ denotes b~seline measurements
,, denotes measurements alter exhaust gas lows passed through
. the catalyst ~hamber
In figures 32 and 33
-. denotes high sulphur fuel baseline measurement
- denotes " " " after catalyst
~ denotes low " " baseline measurement
7 1~ denotes " " ". after catalyst
~ '
In Figures 34 and 3~
I Y~ ~ denotes baseline measurement
denotes prellminary test after catalyst
~ , denotes after catalyst after 7 hours.
J " denotes after catalyst after 50 hours
l Figures 34 and 35 show the effect of time on the properties of the
¦ catalyst.
The maximum temperature on the flange of the catalyst chamber
when the engine is running at a speed of 2,200 rpm and 107 brake mean effect
, pressure lb/in was 103 C and on the outer wall of the chamber was 75 C.
f The back pressure was negligible.
I 15778
i5
The weight of particulates present in the exhaust gas was
measured by passin~ a known volume of exhaust through a dilution tunnel
where it W2S diluted with a set volu~.e of air to ~revent the solids settlin~
before passing the gases through a filter pad. The weight of particulates
enables a value for the par~iculates in g/hr to be calculated. The
particulates present ir the exhaust gas were analysed further to give
thermogravimetric weight, and the weight of volatile components, hydrocarbons,
carbon and sulphate. Using t~e above method a number o~ filter pads
were obtained for analysis. The weight of sulphate in the particulates
was measured by wet chemical analysis of the particulates. Another
sample was placed in a thermo~ravimetric balance where the sample was
heated in an inert atmosphere to a temperature of 780 C until the wei~'ht
~, was constant. The weight loss between the initial weight and the new
gives the weight of volatile components present. A~r was introduc~3d
and heating cont-nued until the weight was again constant. ~he difference
in this weight and the value for the previous constant weight gives the
weight of carbon components present. The re~ainder was ash and non-comoustible
materials such as iron.
~.
'
The results of the analysis of the partic~ tes present
in the exhaust gas for an engine usin~ high and low sulphur fuels are
given in Figures 46-49 Figurcs 46and 4iare with catalyst A in the catalyst
~hamber and Figures 4ga~ld4g are with catalyst B in the catalyst
chamber.
'. .
Table 3 gives sulphate leYels in g/h~ in the particulates using a
high and low sulphur fuel in the engine.
,
Table 4 below gives sul~)hate levels in g/hr in the exhaust
gas using a high sulphur fuel in the engine with catalyst B in the catalyst
I 157780
\ ~ _ 16 _
chamber. Measureme~ts were taken after 7 and 50 hours.
`
,
I 157780
_ 17 -
. ~ . _
- Q~
E~
~ CO~ V~
¢ 2 ~ ~ ~ ~ o
¢ O O .,1 .rl O
C~ ~ Z Z ~ ~ "~
' ~1:'
E~ 3 .
U~ ~
e~ OCn a~ ~ ~ ~r
E~ Zo ~ O ~_l _
. ~ ~ N Z
Z ~
~U~
~ O =~ ~ ~ O~
V~ Z ~o o o o 0~ 0 t-
m c~ m m o o J
_
~ H V~ .
s o ,~ a~, ~ o ~
E~ ~~D . . . t_
~ c~ . . t_ ~ a:~ -
.~ . _ ~ U~
' ` ~ .
! ~ov~
.~ ~ ~ o~ ~ u~
~, ~ Cl . . ~. o~ ~ .
.
.
. H ~ ~q
~d S ~ ~ ~ U~ ~ O O
c/~ bl)1~ OC~
. m ~ :~ ~ _ ~ _ ~ ~ N
¦ . a~ H O
W IS~ 0 :~ ~ N
m ~~-- '~= - ~ ~
E~
' " ` ~
`
~ ~57783
_ 18 _
Table 4
_ .............. _
1400 REV/MIN INITIAL LEVEL g/h AFTER 7 nOUR~ ~. TER 50 HOURS
STABLISING g/h STABLISING g/h
load 2 3.60 0.67 0.6
" 50 2.64 1.32 0.9
" 100 37.68 22.80 9.6
. - ,
2200 REV/MIN
.' _ .
% load 100 53.28 36.20 55.7
" 50 18.00 21.10 15.1C
" 2 5.76 6I~o 2.3
