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 CORPORATION OF 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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* 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

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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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