5396 5400.output

* GB785804 (A)
Description: GB785804 (A) ? 1957-11-06
Improvements relating to thrust bearing arrangements
Description of GB785804 (A)
PATENT SPECIFICATION
785,804 Date of Application and Filing Complete Specification:
July 19, 1955.
No 20880/55 Application made in Germany on July 19, 1954.
Complete Specification Published: November 6, 1957.
COMPLETE SPECIFICATION
Index at acceptance:-Class 12 ( 1), A 5 86.
International Classification: F 06 c.
Improvements relating to Thrust Bearing Arrangements.
We, DAIMLER-BENZ AKTIENGESELLSCHAFT, of Stuttgart Unterttirkheim,
Germany, a Company organised under the laws of Germany, do hereby
declare the invention, for which we pray that a patent may be granted
to us, and the method by which it is to be performed, to be
particularly described in and by the following statement:-
This invention comprises improvements relating to thrust bearing
arrangements and is concerned with thrust bearings of the type
comprising a series of individual bearings, or groups thereof, and
means adapted for distributing the load between individual bearings or
groups of the series Such thrust bearing arrangements are suitable for
being subjected to large thrust loads whilst running at high speed.
Heretofore, means adapted for distributing the load have comprised
balance beams or hydraulic devices but such arrangements are liable to
prove expensive and cumbrous and to be sensitive to mechanical
inaccuracies so as to become the source of undesirable vibration.
According to the present invention, in a thrust bearing arrangement
comprising a series of individual bearings, or groups thereof, and
means adapted for distributing the load between individual bearings or
groups of the series, at least two thrust members of a series each
comprise a wedge surface, said surfaces having engagement in the axial
direction of the bearing with an abutment in such a manner as to be

effective for the load distribution as between one bearing, or group
of bearings, and another.
The invention enables a thrust bearing arrangement to be of simple and
compact construction and nevertheless to be capable of accurate load
distribution, which by a simple device may be made an uneven or
differential load distribution when circumstances require such a
distribution to be (Price 3 s 6 d) effected At the same time excessive
sensitiveness in load distribution is avoided.
The wedge surfaces of the load distributing means may be carried by
split rings or sleeves as herein after more particularly des 50
cribed.
For thrust bearings comprising a comparatively large number of
individual bearings in series, these may be divided into two or more
main groups and load distrib 55 uting means may initially distribute
the load between such groups whilst further distributing means may
distribute the part loads between individual bearings comprising the
respective groups Such an arrangement is 60 applicable in the case
where the series is composed of an odd number of individual bearings
as well as in the case where an even number is concerned.
In some cases, the distributing means may 65 comprise a circular
series of balls in operative engagement with the wedge surfaces so
that comparatively frictionless operation of the distributing means is
attained.
An arrangement in accordance with the 70 invention is capable of
ensuring equalization of the load distribution on all individual
bearings of a series and therefore long life for such bearings
Moreover, it is very reliable in operation and, as it functions 75
mechanically, it is not dependent upon the availability of oil
pressure as is the case with hydraulic arrangements.
In order to enable the invention to be readily understood, reference
is made to the 80 accompanying drawings illustrating several practical
constructions by way of example, in which drawings:Figure 1 is an
axial section of a thrust bearing comprising a series of four individ
85 ual bearings, this Figure also includes a diagrammatic
representation of load distribution over the four individual bearings
by means acting on the balance-beam principle.
Figure 2 is an axial section of a thrust 90 bearing comprising a
series of two individual bearings, this Figure also including a
comprising wedge surfaces in accordance with the invention.
Figure 3 is similar to Figure 2 but shows a modification according to
which a ring of balls is arranged to have operative engagement with
the wedge surfaces.
Figure 4 is generally similar to Figure 1 but it shows the application
to the bearing of load distributing means comprising wedge surfaces in

accordance with the invention.
Figure 5 is an axial section illustrating the application of the
invention to a thrust bearing comprising a series of five individual
bearings.
Figure 6 is a cross section to a larger scale of a detail seen in
Figure 5 and includes a diagram of forces, and Figure 7 is a
perspective view of a split sleeve such as may be used in Figure 4 or
Figure 5.
In Figure 1, the axial load, for example of a hydrostatic gearing, is
introduced in the direction of the arrow x by a shaft 1 It is
distributed initially between an individual bearing 2 and a thrust
sleeve 3 The bearing 2 transmits the part load to a sleeve 4 From the
sleeve 3, a part load is branched off to a bearing 5 The load
equalisation, that is the equal distribution, between the two bearing
2 and 5 is effected at an equalising point 7 From the point 7, the
re-united part loads are transmitted further by way of a sleeve 8 The
remaining axial load transmitted by the sleeve 3 is applied against a
sleeve 9 Thence it is branched by way of a bearing 10 to a sleeve 12
and by way of a sleeve 11 to a bearing 13 Load equalisation between
the bearing 10 and the bearing 13 is again effected at an equalising
point 14 The re-united part loads from the equalising points 7 and 14
experience their total equalisation at an equalising point 15, where
they are transmitted, in the value corresponding to the total axial
load introduced at 1, by a thrust ring 16 to a housing 17.
Conditions are naturally the same if the transmission of thrust is in
the opposite direction, from the housing 17 to the shaft 1.
In Figure 2 there are two bearing 2 and and a wedge ring 6 which
serves as a thrust distributing or equalising member.
The axial load introduced by the shaft 1 is divided between the
bearing 2 and the sleeve 3 The part load from the bearing 2 is
conducted to the sleeve 4, whilst the part load from the sleeve 3 is
applied to the bearing 5 The load equalisation between the bearing 5
and the sleeve 4 is effected by the wedge ring 6 which abuts against
the housing by means of the thrust washer 7 The wedge ring 6 is split
at 6 a and is provided with wedge surfaces 6 b and 6 c which bear
against corresponding wedge surfaces on the sleeve 4 and on the upper
race ring of the ball bearing 5 respectively, the resilience produced
by the split 6 a ensuring, in conjunction with the equal wedge 70
angles of the surfaces 6 b and 6 c accurate load equalisation In the
example illustrated each of the surfaces 6 b and 6 c makes an angles
of 45 ' with the plane of the washer 7 75 Figure 3 differs from Figure
2 in that instead of a wedge ring, thrust balls 6 d cooperate with the
wedge surfaces 6 b, 6 c of the sleeve 4 and the upper race ring of the
ball bearing 5 respectively The balls may be 80 guided, for example,

in cages or in grooves in the thrust washer 7.
In Figure 4, the thrust point 7 of Figure 1 is constituted by a wedge
ring 7 a made in one piece with the sleeve 8, the thrust 85 point 14
is constituted by a wedge ring 18, and the thrust point 15 is
constituted by wedge surfaces of a thrust washer 19.
The sleeve 8 is split as shown in Figure 7, and abuts by means of
inclined surfaces 90 8 b and 8 c (Figure 4) against corresponding
inclined surfaces of the unsplit sleeve 4 and the upper race ring of
the ball bearing 5 respectively The sleeve 8 is provided with slits 8
a and 8 a' which are open alternately 95 downwards and upwards and
produce the resilience of the sleeve These slits extend from
respective ends over the greater portion of the length of the sleeve.
The upper end of the sleeve 8 bears by 100 means of an inclined
surface 8 d against a corresponding inclined surface 16 a on a thrust
washer 16 which abuts, on the other hand, by means of an inclined
surface 16 b against a ring 19 which is split at 19 a and 105 which
bears in turn against a split ring 18 co-operating by means of
inclined surfaces 18 a and 18 b with the sleeve 12 and the upper race
ring of the ball bearing 13 respectively The force transmission corres
110 ponds to that of the diagram included in Figure 1.
Figure 5 illustrates the distribution of the axial thrust among five
ball bearings 2, 5, 10, 13 and 20, on the one hand, a thrust 115
sleeve 16 a, replacing the thrust washer 16 of Figure 4, transmits the
part of the load incident upon it to a split ring 22 and, on the other
hand, the sleeve 11 transmits a residual part of the axial thrust
directly or 120 by way of a sleeve 21 and ball bearing 20 to the said
ring 22, which is abutted in turn against a thrust washer 23 The wedge
surfaces 22 a and 22 b of the ring 22 in this case possess different
angles of inclination 125 to the axis of the shaft 1 such that, as
shown in Figure 6, a relatively large thrust component B is incident
on the wedge surface 22 a and a relatively small thrust component is
incident upon the wedge surface 22 b in 130 785,804 785,804 the
equilibrium condition with a resultant axial thrust A By appropriate
selection of the angles of inclination, the result can be achieved
that, as regards the four thrust bearings 2, 5, 10 and 13, a load
proportion of 4/5 of the total axial thrust is transmitted through the
surface 22 a and, as regards the fifth bearing 20, a load proportion
of 1/5 of the axial thrust is transmitted through the surface 22 b.
If the force transmission is considered as from 23 to 1, then in this
case the axial thrust is first distributed at 22 as 1/5 to the bearing
20 and 4/5 to the sleeve 16 a, whence the last named proportion is
transmited at 19 as half each, that is as 2/5 of the total load, to
the sleeve 8 and the thrust ring 19 Each of the parts 8 and 19 again
distributes the force incident on it as half each, that is as 1/5 of

the total load, to the bearings 13 and 10 on the one hand and to the
bearings 5 and 2 on the other hand.
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* 5.8.23.4; 93p
* GB785805 (A)
Description: GB785805 (A) ? 1957-11-06
Improvements in or relating to fractionation in coker scrubber of heavy gas
oils containing a high concentration of metal contaminants
s 785 T 805 Date of Application and Filing Complete Specification:
ugust 5, 1955.
No 22608/55.
Application made in United States of America on September 3, 1954.
Index at acceptance:-Classes 32, E 2; and 55 ( 1), AK ( 1: 2: 6 A: 6
B: 8).
International Classification: Cl Ob, g.
Improvements in or relating to Fractionation in Coker Scrubber of
Heavy Gas Oils containing a High Concentration of Metal Contaminants.
We Esso RESEARCH AND ENGINEERING COMPANY, a Corporation duly organised
and existing under the laws of the state of Delaware, United States of
America, of Elizabeth, New Jersey, United States of America, do hereby
declare the invention, for which we pray that a patent may be granted
to us, and the method by which it is to be performed, to be
particularly described in and by the following statement:-
This invention relates to improvements in the coking of heavy

hydrocarbon oils wherein heavy gas oils containing a high
concentration of metal contaminants are decontaminated by
fractionation in the scrubbing-fractionation zone of a fluid coker.
During recent years there has been considisrable iicentive for
upgrading residua because of the spread of price between crude and
fuel oil The demand for heavy fuel oil relative to lighter petroleum
products has been steadily decreasing with the years Therefore,
refiners have been seeking economical methods for reducing fuel-oil
production based on vacuum distillation, deasphalting, and coking.
Vacuum distillation has found extensive use in maximizing the
production of catalytic cracking feed stocks, although the extent to
which crude can be reduced by this means is dependent on crude quality
Therefore, the quantity of the resulting residuum may vary from as
little as approximately 4 per cent for such crudes as South Louisiana
to 40 to 50 per cent for some of the heavier crudes which are now
coming into the picture The chief limitation to an increase in the
amount of gas oil taken overhead in vacuum distillation is the
carry-over of traces of metals which contaminate cracking catalysts As
the percentage overhead obtained by vacuum distillation of a
metalcontaining reduced crude is increased, the concentration of metal
in the distillate increases in a regular manner.
There has been developed a process known as the fluid coking process
also for the production of lower boiling distillates from heavier
fractions The fluid coking unit consists basically of a reaction
vessel or 50 coker and a heater or burner vessel Several reactor
stages can be employed In a typical operation the heavy oil to be
processed is injected into the reaction vessel containing a dense
turbulent fluidized bed of hot inert 55 solid particles, preferably
coke particles.
Uniform temperature exists in the coking bed Uniform mixing in the bed
results in virtually isothermal conditions and effects instantaneous
distribution of the feed stock 60 In the reaction zone the feed stock
is partially vaporized and partially cracked Product vapors are
removed from the coking vessel and sent to a fractionator for the
recovery of gas and light distillates therefrom 65 Any heavy bottoms
is usually returned to the coking vessel The coke produced in the
process remains in the bed coated on the solid particles.
The present invention comprises a process 70 for coking a reduced
crude oil which comprises contacting the reduced crude oil at a coking
temperature with a body of inert particulate solids maintained in the
form of a dense turbulent fluidized bed in a reaction 75 zone,
circulating the inert solids through a heating zone wherein a portion
of the inert solids are heated and returned to the reaction zone to
supply heat thereto, transferring hot vapors from the reaction zone to

a 80 scrubbing-fractionation zone, feeding a first gas oil containing
metal contaminants to the scrubbing-fractionation zone, quenching then
vapors therein to condense a high boiling fraction, containing metal
contaminants, and 85 taking off a second gas oil; the second gas oil
having a lower proportion of metal contaminants than the first gas oil
and the high boiling fraction having a boiling range higher than
either the first or second gas oil 90 785,805 The heat for carrying
out the endothermic coking reaction is generated in the heater or
burner vessel A stream of coke is transferred from the reactor to the
usually extraneous burner vessel employing a standpipe and riser
system, air being supplied to the riser for conveying the solids to
the burner.
Sufficient coke or added carbonaceous matter is burned in the burning
vessel to bring the solids therein up to a temperature sufficient to
maintain the system in heat balance.
The burner solids are maintained at a higher temperature than the
solids in the reactor About 5 %O of coke or equivalent, based on the
feed, is burned for this purpose This amounts to approximately 15 % to
30 % of the coke made in the process.
The unburned portion of the coke represents the net coke formed in the
process This coke is preferably withdrawn from the burner, normally
cooled and sent to storage.
The reduced crude oil feeds suitable for the coking process include
heavy or reduced crudes, vacuum bottoms, pitch, asphalt, other heavy
hydrocarbon residua or mixtures thereof Typically, such feeds can have
an initial boiling point of about 700 F., an A P I gravity of about O
to 200, e.g 1 90, and a Conradson carbon residue content of about 5 to
40 weight per cent.
(As to Conradson carbon residue see ASTM Test D-180-52).
It is preferred to operate with solids having a particle size ranging
between 100 and 1000 microns in diameter with a preferred particle
size range between 150 and 400 microns Preferably not more than 5 %
has a particle size below about 75 microns, since small particles tend
to agglomerate or are swept out of the system with the gases.
While coke is the preferred particulate solid other inert solids such
as spent catalyst, pumice, sand, kieselguhr, carborundum, and alumina
can be employed.
Vacuum distillation in a pipe still normally precedes the sending of
the coker heavy feed to the coking system This, of course, produces
the vacuum residuum feed The atmospheric residuum to the vacuum pipe
still can be cut less deeply to avoid the obtaining of an excessively
contaminated heavy gas oil distillate fraction This, however,
decreases the heavy gas oil yield from the distillation and increases
the quantity of material that must be handled in the coker Also it

presents the resultant disadvantage of having to coke excessive
amounts of vacuum bottoms The other alternative is to cut deeper in
the vacuum still and recover larger quantities of heavy gas oil, which
can, however, be excessively contaminated with metals Since the metal
contaminants are less volatile than the gas oil, their removal can
still be accomplished by improved fractionation in an auxiliary vacuum
tower or towers This represents, however, substantial increase in
investment and operating costs.
This invention provides an improved process for removing the metal
contaminants 70 from the heavy gas oils The process comprises feeding
a heavy gas oil containing a high concentration of metal contaminants
to the scrubbing-fractionation zone of the fluid coker 75
Substantially all of the metals are fractionated out in the heavy
condensate and a gas oil substantially free of metal contaminants is
recovered.
The heavy gas oil from which the con 80 taminants are removed
constitutes a petroleum oil having a true boiling temperature range
within the range of 800 to 1350 'F.
Although the problem of metal contamination is most often encountered
in the heavy 85 gas oil from the vacuum pipe still, other fractions in
which the problem also occurs are atmospheric gas oil or residuum,
vacuum residuum, and other contaminated heavy oils 90 The contaminants
most often found are nickel, vanadium and iron organic complexes
Nickel is the most objectionable component since it most deleteriously
effects cracking catalysts The concentration of 95 metal contaminants
is expressed in the art as "nickel equivalents" The term nickel
equivalent is defined herein as the amount of nickel plus one fifth
the amount of vanadium plus one fiftieth the amount of iron; 100 all
of these amounts being expressed in p 3 unds of the metals per 1,000
bbls of oil.
A metal contaminant level of about 0 2 or higher pounds of nickel
equivalent, per 1,000 bbls of heavy gas oil is an undesir 105 ably
high concentration The process of this invention reduces the level of
the contaminants to below 0 10 and even below 0.02 pounds of nickel
equivalent per 1,000 bbls of gas oil 110 This invention will be better
understood by reference to an example and the flow diagram shown in
the drawing accompanying this specification.
In the drawing the numeral 1 is a coking 115 vessel constructed of
suitable materials for operation at 950 '1 F A bed of coke particles
preheated to a sufficient temperature, e g, 1125 'F, to establish the
required bed temperature of 950 'F is made up of suitable 120
particles of 150 to 400 microns The bed of solid particles reaches an
upper level indicated by the numeral 5 The bed is fluidized by means
of a gas such as steam entering the vessel at the stripping portion

125 near the bottom thereof via pipe 3 The fluidizing gas plus vapors
from the coking reaction pass upwardly through the vessel at a
velocity of lft Isec establishing the solids at the indicated level
The fluidizing 130 course be varied with the pressures The
skilled-in-the-art person will be able to select the conditions within
these teachings to reduce the metal contaminants to the desired level
by condensing a heavy fraction 70 containing substantially all the
metal contaminants.
Instead of cooling and recycling heavy condensate to the bottom
section of the tower, other cooling mediums may be used 75 For
example, fresh feed may be fed into this section In this case the
residual feed will be preheated by contact with hot vapors.
Vapors remaining uncondensed in the 80 bottom scrubbing section of the
tower pass upwardly through a series of bubble cap trays located in
the top of the tower where they are subjected to fractionation to
condense an additional fraction in the gas oil 85 boiling range
substantially free of metallic contaminants, e g 0 04 of nickel
equivalents.
The condensate formed in the upper section is withdrawn as a side
stream through line 31 A portion of this stream is pumped 90 back to
the lower section of the tower through line 32 as additional scrubbing
and cooling medium and another portion may be pumped through cooler 33
and introduced into the top of the tower to serve as reflux 95 The
temperature at the top of tower 18 should be kept above the dew point
of steam, i e, at a temperature of at least 2000 to 2250 F This
prevents condensation of steam which, if allowed to occur, might 100
cause emulsion and corrosion problems in the top of the tower The
temperature of the vapors leaving the top of the tower may be about
300 'F.
The heavy condensate fraction withdrawn 105 from the bottom of the
scrubbing tower 18, through line 24, and the portion not recycled for
quenching and scrubbing as before described may be continuously pumped
through line 34 back to the coking vessel 110 1 wherein the metal
contaminants are deposited on the coke This heavy condensate may be
mixed with fresh feed prior to injection or may be injected through
separate nozzles preferably in the lower part of the 115 coking vessel
As an alternative, this heavy condensate may be introduced into a
vacuum tower for further fractionation and the bottoms from the vacuum
tower may be passed to the coking vessel The vacuum 120 tower may be
the same tower in which crude for the coking feed is distilled The gas
oil withdrawn as a side stream through line 31 constitutes a final
product of the process This soil being a condensate relatively 125
free of residual components and metallic impurities may be subjected
to catalytic cracking to form high quality gasoline.

Uncondensed vapors and gas are withdrawn from the top of tower 18
through 130 gas serves also to strip the vapors and gases from the hot
coke from the heater which flows down through the vessel from pipe 9.
A stream of solid particles is removed from the coking vessel via line
8 and transferred to the heater not shown The temperature of the
burner solids is usually 1000 F to 300 'F higher than that of the
solids in the coking vessel, e g, 175 'F higher in this example.
A reduced crude oil to be converted is preferably preheated to a
temperature not above its cracking temperature, e g, 700 'F.
It is introduced into the bed of hot coke particles via line 2,
preferably at a plurality of points in the system The oil upon
contacting the hot particles undergoes decomposition and the vapors
resulting therefrom assist in the fluidization of the solids in the
bed and add to its general mobility and turbulent state The product
vapors pass upwardly through the bed through cyclone 6 from which
solids are returned to the bed via dipleg 7 From the cyclone 6 the
vapors pass into a scrubbing and fractionating tower 18 preferably
mounted directly above the coking vessel although it can be located
elsewhere.
A heavy gas oil (e g boiling between 850 to 1100 HF, having an A P I
gravity of 200, and containing 1 0 pound of nickel equivalent per
1,000 bbls of gas oil) is fed through line 30 into
scrubber-fractionator 18 The oil may be partially vaporized by a
preheat furnace prior to its introduction to tower
18 On entering the scrubber-fractionator, further flashing or
condensation will occur, depending on the boiling range of the oil and
the conditions of temperature and pressure in the scrubber.
The temperature at the bottom of the tower 18 is controlled by
introducing a stream of quench oil through line 21 The condensation is
conducted so as to obtain a condensate boiling predominantly above
1015 'F atmospheric The initial boiling point will be predominantly in
the range of 950 to 10500 F and the quenching ternperature accordingly
adjusted For example, condensate collected in the bottom of the tower
may be removed through line 24, a portion passed through cooler 26 and
returned to the tower at a series of disc and doughnut baffles 27.
The temperature necessary to condense the metallic impurities will
depend on the nature and amount of such impurities present in the feed
It is preferred to operate at the maximum temperature which will
effect removal of impurities Excessive temperatures at this point
would result on the other hand in excessive coking and the carrying
over of the metal contaminants.
The exact temperatures utilized can of 785,805 785,805 line 36, and
passed through a water cooled In order to express this information
more 5 condenser and then to a separating drum fully the following

conditions of operation (not shown) in which the liquid distillate of
the various components are further set separates from uncondensed gas
forth below.
CONDITIONS Temperature, 'F.
Pressure, Atmospheres Superficial Velocity of Fluidizing Gas, Ft I
Sec.
Average Size of Coke Particles, Microns Coke Circulation (Solids to
Oil Ratio) Temperature, 'F.
Superficial Velocity of Fluidizing Gas, Ft / Sec.
IN FLUID COKER 1 Broad Range 850 1500 1 10 0.2 2 0 1000 10 DITIONS IN
BURNER Broad Range 1050 1600 1 5 Preferred Range 900 1000 1.5 2 0.5 1
5 400 7 8 Preferred Range 1100 1200 2 4 The process of this invention
avoids the necessity of constructing separate and auxiliary vacuum
distillation equipment.
Liquid product loss accompanying the removal of contaminants are held
to a minimum since the metals are rejected with the coke.
A very important advantage is the fact that the refiner can cut deeper
in the vacuum pipe still operation because the metal contaminated
heavy gas oil fraction can be economically purified.
Higher overall yields from the crude are obtained Since the
contaminated heavy gas oil is sent to the scrubber-fractionator rather
than relegating a portion of it to the vacuum residuum coker, coker
capacity requirements are minimized Excessive gas oil degradation in
the coker is avoided and a high quality virgin gas oil is obtained
from the pipe still.
The advantage of being able to cut deeper in the vacuum pipe still
operation is exemplified as follows:
Given a pipe still operated at 25 mm Hg hydrocarbon pressure and a
distillation temperature of 820 'F, about 4 wt %, based on the crude,
is obtained as a vacuum residuum This temperature is one that avoids
an excessive metals concentration in the heavy gas oil distillate
Raising the distillation temperature to 860 'F results in a greater
production of the heavy gas oil and only 0 5 % of vacuum residuum The
heavy gas oil is decontaminated as taught and the charge to the coker
is greatly diminished.
The metal contaminants eventually are deposited on the coke particles
This represents a saving as contrasted to their being present in any
of the liquid fuel components.
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* 5.8.23.4; 93p
* GB785806 (A)
Description: GB785806 (A) ? 1957-11-06
Physical treatment of solutions of organic acid esters of cellulose
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The EPO does not accept any responsibility for the accuracy of data
and information originating from other authorities than the EPO; in
particular, the EPO does not guarantee that they are complete,
up-to-date or fit for specific purposes.
Physical Treatment of Solutions of Organic Acid Esters of Cellulose.
We, CELANESE CORPORATIONOF AMERICA, of 180, Madison Avenue, New York
16,
New York, United States of America, a company incorporated in
accordance with the laws of the State of Delaware, United
States of America, do hereby declare the invention, for which we pray
that a patent may be granted to us, and the method by which it is to
be performed, to be particularly described in and by the following
statement:
This invention relates to the preparation of solutions of
monocarboxylic acid esters of cellulose, especially such as have a
high degree of substitution. At present the most important of such
esters are the cellulose triacetates, using this term to denote
cellulose acetates of acetyl value above 58% reckoned as acetic acid.
When cellulose esters of a high degree of substitution, in particular
cellulose triacetates, are dissolved even in good solvents, the
properties of the solutions obtained are not always completely
satisfactory. For example the solutions may be grainy, i.e.
they may appear not to be completely homogeneous, even though the

cellulose ester is in fact fully dissolved. At the same time they may
have very high viscosities, and tend to plug a filtering element
rapidly.
When solutions of this character are employed for the production of
filaments it is found that spinning is not stable and that filaments
are obtained having unduly variable properties; in extreme cases
filament breakage occurs.
It is an object of the present invention to provide a process for
obtaining solutions of monocarboxylic acid esters of cellulose having
a high degree of substitution in which these disadvantages are
mitigated or avoided.
According to the invention, solutions of monocarboxylic acid esters of
cellulose which are suitable for spinning are obtained by a process
which comprises dissolving the cellulose ester in a solvent therefor,
and subsequently reducing the viscosity of the solution by subjecting
it to a vigorous shearing action. By this means solutions can be
obtained which have a smooth homogeneous appearance and a reasonably
low viscosity, so that they can be handled at high concentrations
without using excessive pressures. Moreover the solutions are more
readily filtered than before they are given the shearing treatment and
have less tendency to plug the filtering element. The spinning
stability also is improved, and the filaments obtained vary in their
properties over a smaller range; the tendency to filament breakage is
also much reduced.
The most valuable application of the invention is in connection with
cellulose triacetates, especially such as have an acetyl value above
about 60%. Other cellulose esters to which the invention may be
applied with advantage include cellulose propionate, cellulose
butyrate and mixed esters such as cellulose acetate formate, cellulose
acetate propionate and cellulose acetate butyrate, all containing less
than 0.4 and preferaly less than 0.2 free hydroxyl groups for each
anhydroglucose unit of the cellulose molecule.
The solvent employed may for example be trichloromethane, formic acid
or m-cresol, but it is preferably methylene chloride either alone or
in admixture with a minor proportion of a lower aliphatic alcohol such
as methanol, ethanol, n-propanol, isopropanol or a butanol, since when
the solvent consists of or comprises mainly methylene chloride there
are obtained solutions that are especially well suited for the
production of filaments by conventional spinning operations. The
concentration of the cellulose ester in the solution may vary over a
wide range, depending on the use to which the solution is to be put,
but the invention is particularly useful when applied to solutions of
cellulose ester concentration exceeding about 12 o and especially
exceeding about 15% based on the weight of the solution.

Looked at from another angle, the main advantage of the invention is
in connection with solutions which before being given the shearing
treatment have a viscosity above about 100 poises and especially above
about 300 poises. At these relatively high concentrations and
viscosities the disadvantages previously referred to become especially
severe, and the advantages obtained through the use of the invention
become correspondingly great.
In the shearing treatment the solutions are subjected to a shearing
action in which the rate of shear should be at least 20 and preferably
about 60 or more reciprocal seconds.
(By "rate of shear we mean the value of
V when v is the linear speed in centimetres
d per second d the tip3 of the impellor blades or other means causing
the shear, and d is the distance in centimetres from these tips at
which the velocity in the body of the solution drops to zero.) The
time required will depend on the rate of shear and also on the
dimensions of the apparatus employed. For example when high rates of
shear are employed the treatment may need less than 15 minutes, but
with relatively low rates of shear a treatment time of about 12 hours
may be required. It is preferable to continue the treatment until such
time as treatment for a further 0.5 hours will cause a drop in
viscosity of less than about 5%. In general the integrated shear, i.e.
the rate of shear multiplied by the time of treatment in seconds,
should be at least about 36,000.
The shearing treatment may be carried out in any suitable type of
apparatus, such for example as apparatus equipped with a paddle type
impeller which can be operated at speeds sufficiently high to give the
desired rate of shear. The paddles may be provided with a number of
small openings so as to increase the volume of the solution which is
continuously subjected to the high rate of shear. In other methods the
solution may be passed through a homogenising mill or may be subjected
to supersonic vibration.
The invention is further illustrated by the following Examples, in
which all parts and percentages are by weight.
EXAMPLE I
A cellulose triacetate of acetyl value 62.5% was tumbeld for 8 hours
with sufficient of a solvent mixture of 92 parts of methylene chloride
to 8 parts of methanol to give a solution having a cellulose
triacetate concentration of 18.4% based on the weight of the solution.
At this stage the solution had a viscosity of 490 poises. Part of the
solution was then introduced into a paddle type stirrer, the impeller
of which was operated at 1700 revolutions per minute to give a shear
rate of 65 reciprocal seconds through the entire volume of the
solution, and stirring was continued for 15 minutes. The viscosity of

the treated solution had then dropped to 400 poises, and the initial
rate of filtration through a standard filter was 47.5O,. greater than
that of the untreated solution. The total volume of solution that
could be forced through a standard filter at a given pressure before
plugging occured was 10.7 times as great as in the case of the
untreated solution.
EXAMPLE 2
Another part of the same solution was given the same treatment, except
that the duration was extended to 60 minutes. The treated solution had
a viscosity of 370 poises, the initial rate of filtration was 70%,
greater than that of the untreated solution, and the total volume of
solution that could be forced through the filter at a given pressure
before plugging occurred was 21.5 times as great as that of the
untreated solution.
It will be understood that throughout this specification references to
the "viscosity9' of a solution are to its absolute viscosity, in the
sense of its viscosity as determined some time after the end of the
shearing treatment by a given method at a given temperature.
Specific figures for viscosities given in the specification and claims
are as determined using a Brookfield viscometer at 25"C., working at
10 revolutions per minute. A description of the Brookfield viscometer
and its use will be found in Modern Plastics 33 (Nov. 1955) page 140.
What we claim is:
1. A process for the production of a solution of monocarboxylic acid
ester of cellulose suitable for spinning, which comprises dissolving
the cellulose ester in a solvent therefor, and subsequently reducing
the viscosity of the solution by subjecting it to a vigorous shearing
action.
2. Process according to Claim 1, wherein the cellulose ester contains
less than 0.4 free hydroxyl groups per anhydro-glucose unit of the
cellulose molecule.
3. Process according to Claim 1, wherein the cellulose ester is a
cellulose triacetate as hereinbefore defined.
4. A process for the production of a solution of a cellulose
triacetate suitable for spinning, which comprises dissolving a
cellulose triacetate of acetyl value at least 60% in methylene
chloride or in a solvent mixture of methylene chloride and a lower
aliphatic alcohol, and subsequently reducing the viscosity of the
solution by subjecting it to a vigorous shearing action.
5. Process according to Claim 3 or 4, wherein the concentration of the
cellulose

* GB785807 (A)
Description: GB785807 (A) ? 1957-11-06
Magnetic recording and reproducing system
785,807 Date of Application and Filing Complete Specification:
September 2, 1955.
No 25259/55 Application made in United States of America on September
28, 1954.
Index at acceptance:-Classes 40 ( 2), D 3 A 2; and 40 ( 4), G 24 (A 4
B: Bl B).
International Classification Gl Oj, H 104 b.
Magnetic Recording and Reproducing System.
We, Esso RESEARCH AND ENGINEERING COMPANY, a Corporation duly
organised and existing under the laws of the State of Delaware, United
States of America, of S Elizabeth, New Jersey, United States of
America, do hereby declare the invention, for which we pray that a
patent may be granted to us, and the method by which it is to be
performed, to be particularly described in and by the following
statement:-
This invention relates to a frequency modulated magnetic recording and
reproducing system, in which provision is made to eliminate the noise
and distortion normally occuring during recording and play back due
primarily to mechanical features of the recording and reproducing
system.
The present invention comprises a frequency modulated magnetic
recording and reproducing system comprising a first oscillator
producing a carrier frequency signal to which an incoming first signal
is fed to produce a frequency modulated signal, either the first
oscillator or a second oscillator producing an auxiliary carrier
frequency signal having the same frequency as the carrier frequency of
the first oscillator, a magnetic recorder recording simultaneously but
separately the modulated output of the first oscillator and the
unmodulated auxiliary signal, a reproducer simultaneously but

separately reproducing the two recorded signals, two discriminato Irs
to demodulate separately the two signals, and an amplifier into which
the demodulated outputs from the discriminators are fed in opposite
phase to each other to produce a substantially noise-free signal
output which corresponds to the incoming first signal.
The effect of passing the demodulated outputs from the discriminators
in opposite phase is to subtract the auxiliary signal from the
demodulated incoming signal so that any noise or distortion due to
mechanical features of the recording and reproduc(Price 3 s 6 d) MIDG
4 Rt ing system due for example to changes in speed of the magnetic
record become cancelled out.
While the present invention has application to frequency modulated
magnetic re 50 cording and reproducing systems generally, as employed
in many fields, the invention has particular application to seismic
prospecting In seismic prospecting, it is necessary to detect and
record frequencies in the 55 general range of about 20 to 100 cycles
In order to record signals of this frequency over a very wide range of
amplitude levels in a magnetic recording system, it is desirable to
frequency modulate the seismic sig 60 nals so as to obtain a modulated
signal which can best be recorded by the magnetic recording technique
For this purpose a carrier frequency between 1000 and 3000 cycles per
second is preferably employed 65 It is of course, a characteristic of
a frequency modulated magnetic recording system that any changes in
the speed of the magnetic record during either recording or play back
will result in the introduction of 70 undesirable signals or noises to
the output signal When used for seismic signals, the type of noise
encountered can obsure significant evidence on the seismic record or
can be mistaken for significant information 75 Attempts to overcome
this difficulty by high precision speed control of the record medium
during recording and play back are theoretically sound but practically
difficult to obtain It is therefore the purpose of this 80 invention
to provide a simple and effective means for cancelling out the effects
of changes in speed of the magnetic record.
The signal that is to be recorded in the seismic exploration process
covers a very 85 wide range of amplitudes It is at the time that the
signal amplitude is very low that the noise resulting from mechanical
features of the recording process is disturbing In using the magnetic'
recording system for 90 1 i 1 C C ' ' -, 785,807 seismic recording, it
is common to employ a bank of as many as 20 or 30 recording heads
arranged over a magnetic recording tape so that a considerable number
of separate recorded traces can be simultaneously prepared During play
back, a similar bank of pickup heads are used The present invention
can be readily and simply applied to recording systems of this general
character by using one of the recording and one of the play back heads

to handle the auxiliary signal The auxiliary signal must have the same
frequency as the carrier frequency of the oscillator for the modulated
incoming signal It is particularly attractive to employ the
unmodulated output of the carrier frequency oscillator as the
auxiliary signal At the time of recording, a magnetic record will be
prepared having the desired number of frequency modulated signal
traces In addition, a single trace corresponding to the unmodulated
carrier frequency will be recorded Noise introduced into the modulated
signal traces due to changes in record speed will similarly be
injected into the unmodulated auxiliary trace After reproduction of
the modulated signal and the unmodulated auxiliary trace, both traces
are demodulated in discriminators and the outputs from the two
discriminators are fed in opposite phase to an amplifier in such a way
that the demodulated auxiliary signal is subtracted from the
demodulated first signal Noise introduced during either recording or
play back will effect both traces equally and consequently, the
subtraction of one signal from the other will cancel out this noise
from the signal output.
The accompanying drawings diagrammatically illustrate the principles
of this invention in the form of block diagrams showing the essential
features of the invention.
Figure 1 diagrammatically represents a frequency modulated magnetic
recording system.
Figure 2 diagrammatically represents the play back system employed
with the system of Figure 1.
For purposes of simplicity the drawings s O illustrate the application
of the invention in the recording and play back of a single signal As
indicated, it will be understood that the invention can well be
employed when a plurality of signals are to be simultaneously recorded
Referring to Figure 1, the signal to be recorded modulates a carrier
frequency in order to obtain a frequency modulated signal By way of
example, the oscillator 2 may have a frequency of about 2000 cycles
The signal to be recorded in the event that this signal is the output
of a seismic detector will have a frequency of about 20 to 100 cycles
When the seismic signal modulates the carrier frequency, a modulated
signal will be obtained having a frequency of about 1000 to 3000
cycles, for example This modulated signal is then magnetically
recorded by recorder 4 In using this invention, the unmodulated output
of oscillator 3 is also recorded as a sep 70 arate trace by recorder 4
By recording both the modulated and unmodulated oscillator outputs at
the same time, employing parallel recording heads, it is apparent that
both the recorded records will be equally respon 75 sive to any
changes in the record speed during recording so that both recorded
traces will have the same distortion and noise.

During play back, parallel pickup heads 80 are arranged on the play
back unit 5 so that the modulated signal trace and the unmodulated
auxiliary trace will be simultaneously reproduced The modulated signal
output picked up during play back will be 85 applied to a
discriminator 6 in order to obtain a demodulated signal Similarly the
unmodulated auxiliary signal will be passed to a discriminator 7 in
order to obtain a demodulated output It is apparent that the 90 output
of discriminator 7 will be nil in the event that no noise has been
encountered in the recording system during either recording or play
back However, the output of discriminator 7 will constitute an auxili
95 ary signal corresponding to any noise which may have been developed
during recording or play back The output of discriminator 7,
constituting noise, will also of course be present in the output of
discriminator 6 100 Consequently, by subtracting the output of
discriminator 7 from the output of discriminator 6 in the circuit
indicated as a difference amplifier in block 8, a signal output is
obtained free of the noise referred 105 to.
This invention concerns a frequency modulated magnetic recording
system in which an auxiliary record trace is prepared, which is used
to carry only noise components dev 110 eloped during recording or play
back This auxiliary record trace is then subtracted from the
conventional traces after play back so as to eliminate noise from the
final signal output The invention has been described 115 with
reference to simple block diagrams showing the essential principles of
the invention although it will be understood that this invention as
normally employed will necessarily include the amplification stages,
120 modulation stages, etc, ordinarily employed in magnetic recording.
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* 5.8.23.4; 93p
* GB785808 (A)
Description: GB785808 (A) ? 1957-11-06

Welding steel for developing high surface hardness under impact
A high quality text as facsimile in your desired language may be available
amongst the following family members:
BE542504 (A) FR1134233 (A) US2711959 (A)
BE542504 (A) FR1134233 (A) US2711959 (A) less
Translate this text into Tooltip
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The EPO does not accept any responsibility for the accuracy of data
and information originating from other authorities than the EPO; in
particular, the EPO does not guarantee that they are complete,
up-to-date or fit for specific purposes.
785,808 Date of Application and filing Complete Specification: Nov 2,
1955.
No 31395155.
Application made in United States of America on Nov 3, 1954.
Complete Specification Published: Nov 6, 1957.
Index at acceptance:-Class 82 ( 1), A 8 (A 2: A 3: M: Q: R: U: Y: Z 2:
Z 5: Z 8: Z 12), A 15 A.
International Classification:-C 22 c.
Welding Steel for Developing High Surface Hardness under Impact We,
WERKZEUGMASCHINENFABRIK OERLIKON BUHRLE & Co, a Body Corporate
organized under the Switzerland laws, of 230 Birchstrasse,
Zurich-Oerlikon, Switzerland, do hereby declare the invention for
which we pray that a patent may be granted to us and the method by
which it is to be performed, to be particularly described in and by
the following statement: -
This invention relates to welding steel, i.e, steel which can be
weld-deposited, which has important improved characteristics.
Austenitic steels of a number of analyses have been used successfully
for hard facing applications The steels suitable for such ase, being
austenitic or largely so, have a relatively low level of hardness as
deposited but have the property of work-hardening under impact to
higher surface hardness levels which resist wear The utility of such
steels to resist wear therefore depends upon ( 1) the original

hardness level; ( 2) the speed with which hardness is increased under
impact; and ( 3) the level of increased hardness produced under
impact.
An undesirable property in such steels for many applications is the
property of deforming or squashing down which the steel undergoes in
developing its hardened surface That property is especially
undesirable in applications such as deposits on rail ends, switch
frogs, etc, in which the metal should remain standing up in place as
it develops its hard surface.
Since the development of the Hadfield manganese steels about 1886
various modified and improved austenitic type steels have been
employed and used They have manifested differing combinations of
physical properties and have had utility but they have left much to be
desired There is a great need for significant improvements in physical
properties which will bring about improved performance.
The following Table shows the properties of three known alloy steels
numbered consecutively from 1 to 3.
(pice 3 s 6 d 1 I F 785,808 TABLE I
Prior hard surfacing welding steels No 1 2 3 C (%) 70 70 50 Cr (%) 18
18 Mn(%) 14 4 4 Ni (%) 4 9 5 9 5 N (%) O 5 05 05 Mo (%) 1 5 Tensile
(lbs /sqin) 125,000 116,000 116,000 Yield (lbs /sq in) 60,000 90,000
91,000 Elongation (%) 45 15 15 Shrinkage on Impact (in) 068 0 50 050
Rc Initial 13 27 27 Rc Final 39 36 36 Estimated The steels shown in
the foregoing Table are typical austenitic type alloy welding steels
now widely used for hard surfacing No 1, sold under various names
including " Hardalloy 118," is a nickel-manganese steel based on the
old Hadfield steel analyses (similar steels are being used with
molybdenum at the relatively low level of approximately 1 %
substituted for all the nickel and with properties rather similar to
the nickel-manganese alloys).
The physical properties appearing in the table show that the metal is
quite soft as deposited with a yielding strength of less than half the
tensile strength Under impact the surface hardness of the metal
increases A laboratory test which has been developed for such
materials is to subject a standard sample rod to 2500 blows of 25
foot-pounds each The hardness of the pounded metal is compared with
the initial value to show the rate of increase, and the amount of
squashing down which has occurred is also measured.
The final hardness shown under the hammer test values would continue
to increase, if the test were continued, to a maximum value between 50
and 60 Rc at 80,000 blows The additional squashing which would occur
after the first 2500 blows is negligible as compared with the
squashing effected by the first 2500 blows Under the pounding test (
2500 25 foot-pound blows) the " Hardalloy 118 " went from a surface

hardness of 13 Rc to 39 Rc and at the same time the standard specimen
decreased 068 " in height.
Steels Nos 2 and 3 of Table I, sold under the trade names " Frogalloy
M " and " Frogalloy C," respectively, are modified 18-8 type
austenitic hard facing materials of higher cost than No 1 Although Nos
2 and 3 have a little lower tensile strengths they show higher yield
strength, higher hardness as deposited and less squashing or shrinkage
under the standard pounding test Because of these properties the "
Frogalloy " deposits or closely similar analyses have been considered
superior for many hard facing uses The properties of these modified
18-8 analyses were the best that had been developed in the field of
austenitic welding steels for producing hard surfaces prior to the
present invention.
The present invention is based in the discovery that superior
properties can be developed by the proper balancing of chromium,
manganese and nickel coupled with carbon and nitrogen within defined
limits, and that further improvement in properties can be obtained by
addition of molybdenum and/or tungsten, and/or vanadium and/or
columbium within defined limits.
By the present invention there is provided a weld deposit having the
following composition by weight:
785,8083 Percentage of Carbon (C) Percentage of Manganese (Mn)
Percentage of Nickel (Ni) Total Mn + 2 Ni Percentage of Chromium
Percentage of Nitrogen Percentage of Molybdenum and/ tungsten (Mo
and/or W) Percentage of Vanadium, and/or Columbium (Vand/or Cb) Total
Mo and/or W + 2 (V and/or Cb) from (C-0 70) to 1 O(C + 0 20) the
expression (C-0 70) being taken as zero if C-0 70 is negative; the
balance, except for any innocuous impurities, being iron.
By the present invention there is also provided such a weld deposit in
a work hardened state and also a composite article comprising from 0 2
to , 9 to , 0 to , 13 to , 11 to , 0 to 0.85 19 4 22 21 0.30 , 0 to 5
, 0 to 2 a metallic structure having such a weld deposit formed
thereon.
The following Table shows examples of six different welding steels
numbered consecutively from 4 to 9 as provided by the invention,
together with test results obtained therewith.
TABLE II
Improved welding steels No 4 5 6 7 8 9 C (%) 35 35 30 40 50 40 Cr (%)
20 3 12 5 16 16 16 16 Mn(%) 12 5 16 16 16 16 16 Ni(%) 1 1 1 1 1 1 N
(%) 05 05 14 15 15 15 Mo(%) 0 0 0 00 2 2 V (%) 0 0 0 8 8 8 Tensile
(lbs /sq in) 134,000 115,000 130,000 144,000 152,000 144,000 Yield
(lbs /sq in) 93,000 73,000 97,000 117,000 120,000 121,000 Elongation
(%) 24 44 38 24 23 21 Shrinkage on Impact 033 0 59 054 0111 021 026 Rc
Initial 27 18 29 31 30 30 Rc Final 39 40 34 38 36 40 With steel No 6

of Table II, pound test value and hardness levels before and after
pounding are approximately the same as for the modified 18-8 type (Nos
2 and 3 of Table I) but the tensile strength, yield strength and
elongation are much improved.
Steels Nos 4 and 5 of Table II which are toward the ends of the
chromium-manganese area are found to be most useful and show that
while the properties vary somewhat a high general level is maintained
over the ranges given above, for example, steels Nos 7, 8 and 9 of
Table II, taken as a group show very high tensile and yield strengths,
good elongation, 40 good resistance to shrinkage on impact, high
initial hardness and good final hardness Their properties average far
beyond those which have been found in the chromium-nickel or 785,808
austenitic manganese alloys heretofore available.
It is found that two relationships are important The first is the
balance between the austenitizers (C, M, Ni, N) and ferritizers (Cr,
W, Mo, Cb, V) This balance must be adequate to produce a strong matrix
With all the austenitizers near the low limits of their range and the
ferritizers near the high limits of their ranges the mechanical
properties are little or no better than those of the modified 18-8
type welding steels mentioned above.
For this reason the total Mn + 2 Ni (which defines the effective sum
of manganese and nickel in accordance with standard metallurgical
practice in relation to austenitic alloys) is preferably from 16 to 22
%.
The second important relationship is that between carbon and the
strong carbide formers (Cr, W, Mo, Cb, V) To illustrate, assume that
an optimum balance has been found between the austenitizers and the
Percentage of Carbon (C) Percentage of Manganese (MD Percentage of
Nickel (Ni) Total Mn + 2 Ni Percentage of Chromium Percentage of
Nitrogen Percentage of Molybdenum an tungsten (Mo and/or W) Percentage
of Vanadium and/ columbium (V and/or Cb) Total Mo and/or W + 2 (V
and/or Cb) from 1 O(C-0 60) to 10 (C-0 10) the expression (C-0 60)
being taken as zero if C-0 60 is negative; the balance, except for any
innocuous impurities, being iron.
Silicon will normally be present in quantities up to 1 5 or even 2 %
since it is present in the commercial material available as core wire
and is usually used as at deoxidizer in the coatings of coated welding
electrodes.
Other strong carbide formers such as tantalum Percentage of Carbon (C)
Percentage of Manganese (Mn Percentage of Nickel (Ni) Total Mn + 2 Ni
Percentage of Chromium Percentage of Nitrogen Percentage of Molybdenum
an.
tungsten (Mo and/or W) Percentage of Vanadium and/( columbium (V
and/or Cb) ferritizers to form a good matrix such as is present in

steel No 6 of Table II; as more strong carbide former is added carbon
should be added in small amounts to maintain the alloy balance Carbon
and nitrogen exert their usual strong austenitizing action and a
carbon content of 0 35 to 0 85 % is needed to maintain the hardness
level and wearing quality developed in the welding steel In the
welding steel vanadium is approximately twice as powerful as
molybdenum Tungsten and columbium can be substituted respectively for
all or part of the molybdenum and vanadium.
The limits for molybdenum and/or tungsten plus twice the vanadium
and/or columbium i.e for the said total Mo and/or W+ 2 (V and/or Cb)
are preferably from 10 (C-0 60) to 10 (C-0 10)%.
The preferred weld deposits provided by the present invention have the
following composition by weight:
from 0 35 to 0 85 l) from 14 to 18 from 0 to 2 from 16 to 22 from 14
to 19 from 0 10 to 0 25 gd/or from 0 to 5 or from 0 to 2 or titanium
could theoretically be substituted for the carbide formers listed but
are hard to recover in weld deposits.
The deposit analyses disclosed can be produced by the various methods
of manual and automatic welding, as, for example shielded arc, inert
arc, submerged arc or acetylene.
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