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Патент USA US2409708

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0d’ 22, 1946-
'
B. E. RoE‘rHELl
2,409,707
CEMENT IMHUFACTURE
Filed Jan. 29, 1943
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2,409,707
Patented Oct. 22, 1946
UNITED STATES ` PATENT OFFICE
2,409,707
CEMENT MANUFACTURE
Bruno E. Roetheli, Cranford, N. J., assigner to
Standard Oil Development Company, a corpo
ration o! Delaware
Application January 29, 1943, Serial No. 474,008
7 claims.
(o1. 10e-10o)
'
l
This invention relates to improvements in the
Fig. 3 is a partly sectional view of a multi sec
manufacture of cements and relates particularly
tional reaction vessel.
Referring to the drawings, Fig. 1. the raw ma
to improvements in the `methods of heating the
compositions used in the manufacture of ce
ments.
,
'I‘wo processes are employed for the manufac
ture of cements which are known respectively as
the "wet process” and “dry process.” The wet
process is the older of the two and is used almost
universally in Europe while the dry process is
employed to a greater extent here. The essen
tial difference between the two processes is that
terial consisting of the properly adjusted quan
tities of calcareous materials, that is, limestone
and clay materials, are introduced into grinding
mills designated by the numeral I. A plurality
of mills may be used and the grinding is prefer
ably done dry. The mixture of raw materials is
reduced to a iineness so that at least 90% will
pass through a 100 mesh sieve. This finely dì
vided raw material is introduced by means of pipe
the limestone and the clay in the Wet process is
2, or any suitable conveying means, into a con
mixed with water, ground and burned wet while
tainer 3. A finely divided material is then passed
in the dry process the raw materials are ground, 15 through pipe 4, provided with gate valve 5 into
dried and burned.
.
‘
igiepe 6 where it is conveyed to the reaction cham
Formerly the burning of the mixed raw mate
rials was done in intermittent upright kilns.
- The `finely divided material is fluidized as it
These wereV soon improved so as to economize
passes to the reaction chamber 'I1 by blowing‘a
r 1.
,
fuels by making them ` continuous in action. 20 gasthrough the finely divided material at the
rate of the order of at least 0.01- to~0.05 cubic foot
Where upright kilns were used, the mixture of
raw materials and fuel was introduced at the top
and the finished material removed from the bot
tom and crushed to the desired size. Later ro
tary kilns were developed which are long cylin 25
ders supported at a very slight pitch (1/2 to 3A
inches to the foot) from the horizontal and are.
slowly rotated as the raw materials are added.
This type of kiln is generally heated by powdered
per pound of powder. The gas is supplied by
means of pipes 8 and 9. The fluidized ñnely di
vided material behaves like a liquid and has many
of the hydraulic properties of a liquid in that '
l. It flows through pipes under the inñuence
of an unbalanced force such as gravity, differen
tial pressures, etc.
'
2. It tends to assume the shape of the con
coal but sometimes natural gases or fuel oil are 30 tainer.
3_. It flows through conduits or pipes accom
used. The coal is blown in by a blast of air sup
panied by a pressure drop.
plied by a. fan. Commercial rotary kilns vary in
4. Gas seals can be produced in the same man»
size from about 6 feet to 11 feet in diameter and
ineras a liquid is used to seal a gas holder.
have capacities from 200~to 2500 lbs. per day.
The finishedclinker material is yground to the 35 Thereaction chamber 'I is provided with a cy
clone separator IIJ in the upper part and divided
desired size to impart hydraulic properties. ` In
the rotary kiln process., drying, calcining oflime
into three or more sections as II, I2, and I3, by
means of grids I4 andv I5. The finely divided ma
stone and clinkering occurs to some extent con
terial in each section is in an ebullient state simi
currentlyrat high temperatures with ineñicient
utilization of heat owing to by-passing of large 40 lar to that of a boiling liquid. In section II it is
preheated and dried `by hot gases passing up
volumes of hot gases.
`
wardly through grid I4. The finely ground raw
One object of Athis invention is to reduce the
material as it dries continuously flows over baille
amount of fuel necessary to manufacturecement.
I6 through outlet I'I which .is provided With- a
Another object is to conduct the various stages
of processing at temperatures most favorable to 45 butterfly valve I8 to a second sectionV I2 in reac
tion chamber l which is likewise supplied with a
each stage.
baille I9 and butterfly valve20. Fuel gas is in
These and other objects of the invention will
be understood on reading the following descrip
troduced into lower part of section I3 by means
tion with reference to the accompanying _draw
of pipe 2| and air is provided by means of pipe
50 22. Air is admittedthrough heater 23 and passes
ings.
,
Fig. l is a diagrammatic plan‘ view, partly‘in
up through pipe 24 to section I3 of the chamber
section, representing the method‘and apparatus.'
Fig. 2 is a diagrammatic plan view.l partly in
section representing an alternate arrangement oi
apparatus, and
where the mixture of air and fuel gas burn and
supply the desired temperature which may be as
high as l400° C. inbrder to “clinker” the finely
divided material.
2,409,707
3
i
The calcined mixture from the section I2 flows
over the baffle I9 into “clinkering” zone I3. The
hot gases after passing through the ground mix
ture in section I3 pass upwardly through grid I5
to section I2 and are used to calcine the powdered
mixture in section I2. 'I'he hot gases then pass
through grid I4 to section Il to dry the ground
material first introduced into the reaction cham
ber. To avoid high temperatures in section I I in
the upper part of the chamber, cool gas, such as
oxygen, CO2 or a suitable inert gas may be intro
duced in section I2 by means of pipe 25, provided
through pipe 6I into the second reaction vessel
55. The heated gases removed from reaction ves
sel 55 may be passed to reaction vessel 4I by means
of pipes 62 and 63 provided with valves 64 and
65 or through pipes 62 and 5I to the waste heat
boiler 52. The clinkered material from reaction
vessel 55 is removed through pipe 6I and preheat
ing vessel 66 in which sensible heat from the
_clinker preheats the air for combustion. A screw
conveyor 66 removes the clinkered material from
vessel 66 for further grinding and packaging. A
fraction of the clinkered material may be with
with valve 26 to cool the gases as they pass
through grid I4. The “clinkered" material is re-.
drawn from pipe 6I through pipe 61 provided with
valve 66 and returned to the clinkering zone. Air
moved from the bottom section I3 through pipe 15 is passed into pipe 61 by means of pipe 9i pro
21, through air preheater 23 and by means of
vided with valve 62 where the fraction is re
screw propeller 26 passes to a waste heat boiler
cycled to the clinkering zone valves 93 and 94
29 where it is partially cooled and the heat used
being used to regulate the ilow. 'I'he powdered
to provide steam for actuating pumps, drives,
material being removed through pipe 53 may
air compressors, etc. Any included gases are re 20 likewise be separated into two parts. The part
moved from the upper part of the waste heat
removed through pipe 95 being recycled to the
boiler 26 through pipe 36 which is likewise pro-Y
lower section 41 of the reaction vessel 4I, air be
vided with a cyclone separator or bag filter 3'I_
ing furnished through pipe 96 provided with valve
to separate any solid particles. The calcined dry
61. Pipe 66, with valves 96, |66, I6I, and |62
material is then removed by means of screw con 25 being provided to regulate the air supply to reac
veyor 32 from the lower part of the waste heat
tion vessels.
boiler 29 and passed to the grinding and packag
Referring to Fig. 3, a reaction vessel is repre
ing mills (not shown).
'
sentedvby the numeral 16 which is provided with
A portion of the clinkered material in pipe
a plurality of grids 1I, 12, and 13, baifles 14 and
21 may be withdrawn through pipe 33 provided 30 15, and butterfly valves 16 and 11. Into the
with valve 34, fluidized by means of air pro
upper part of the reaction vessel is passed pow
vided by pipe 35 and recycled through pipe 36 to
dered material by means of pipe 16. The pow
the clinkering section I3. Control means may be
dered material is provided with sufficient gas
provided on the valve 4. and the screw propeller
which together with the gas arising upwardly
26 actuated by level 31 in order that the required
through grid 1I is suilìcient to ñuidize and to
levels in reaction chamber 1 may be automati
maintain a level of 16 above the grid 1I. The
cally maintained.
l
'
fluidized powder is heated by means of the gases
Alternately, separate drying, preheating, and
arising through grid 1|, dried and continuously
clinkering chambers may be provided as shown
passed over baille 14 through the passage formed
by Fig. 2. Referring to the drawing, the powdered 40 by baille 14 and outside wall of reaction vessel
raw material is introduced by means of pipe 46
into the upper part of a reaction vessel 4I which
reaction vessel is provided with a grid 42 dividing
the reaction vessel into two parts. An opening
43 formed by baille 44 and the outside wall of
the reaction vessel 4I affords a passage between
the upper section 46 and the lower section 41.
The opening 43 is provided with a butterñy valve
45. - Into this reaction vessel 4I is also passed a
16 to the lower section above grid 12 where it is
further heated to drive oil.’ carbon dioxide. The
iiuidized powder above grid 12 as it is being
heated, continuously passes through the passage
formed by baille 15 and into the section above
grid 13 where fuel, such as fuel oil, and air is
provided through pipe 16 which on combustion,
is suilicient to raise the temperature to any de
sired degree. Flue gases and other reacting
fuel, such as fuel oil or powdered coal, by means 50 gases may likewise be introduced into the lower
of pipe 46 and oxygen or an oxygen-containing
part of the reaction vessel 10 to maintain the
gas such as air by means of pipe 46. The pow
solid in a tluidized condition. The product in
dered raw material introduced by means of pipe
a clinkered state is removed through pipe 18.
46 in reaction vessel 4I is furnished with a sufll
Portions of the product passing through pipe 16
cient quantity of gas to iluidize the powdered
may be Withdrawn through pipes 60 and 68 and
raw material and to maintain a level 56. It is ' passed through pipes 6I and 62 into which is also
there dried by heat supplied by the hot gases
provided gas by means of pipes 63 and 66 for
rising upwardly through grid 42. 'I'he iluidized
recycling clinkered solids to the desired levels
dried material as it is dried, overflows baille 44
of the reaction vessel. that is, the level above grid
through passage 43 to a lower section where it is
60 ‘l2 or the level above grid 13 as desired. A por
still heated further to `drive oil carbon dioxide.
tion of the material may likewise be withdrawn
'I'he carbon dioxide and moisture are removed
as it passes through a passage such as is formed
from the reaction vessel 4I by means of pipe 5I
by baille 14 by means of pipe 63 and passed
after passing through cyclone separator 33 and
through a heat exchanger 64 and recycled to an
passed to a waste heat boiler 52. The powdered
65 upper part of the reaction vessel 16 such as a
material, after being heated in reaction vessel
level above grid 1I.
4I, passes through pipes 53 and 54 to a second
I claim:
reaction vessel 56 into which fluidized powdered
l. In the manufacture of cement, the im
material is introduced clay or other ingredients
provements which comprise reducing the lime
used in preparing cement by means of pipe 56. 70 and clay materials used in the manufacture of
Fuel is likewise passed through pipe 51 provided
cement to a ñneness so that at least 90% will
with valve 56 and pipe 36 into the reaction vessel
pass thorugh a 100 mesh sieve, fiuidizing the iine
66.
Oxygen or oxygen-containing gas such as
powder by contacting with continuously flowing
gas and progressively raising the temperature of
_ air after passing through a preheater 66, passes 75 the iluidized powder by passing a heating gas in
air, is likewise provided through pipe 56 which
2,409,707
countercurrent flow to said material at reduced
velocity adjusted to maintain a dense turbulent
body of said solid materials to iirst drive off the
moisture, second the c-arbon dioxide and third,
to clinker the finely divided material.
2. In the manufacture of cement, the im
5. In the manufacture of cement the improve
ment which comprises continuously passing a
stream of solid material comprising lime and
`clay material into an enlarged reaction zone,
been clinkered by the said high temperature and
cement, reduced to a iineness so that at least 90%`
20 would pass through a 100 mesh sieve, through
passing a heating gas, while at a temperature
suñicient to convert said solid material into
cement, upwardly through said enlarged zone at
provements which comprise reducing ingredi
reduced velocity adjusted tomaintain a dense
ents used in the manufacture of cement to a
turbulent body of solid material within said zone,
iine powder so that at least 90% will pass through
a 100 mesh sieve, blowing the fine powder con 10 maintaining said solid material in contact with
said heating gas for a period of time suñicient
tinuously with suflîcient gas to maintain the tine
to convert said solid material into cement, with
powder in a iiuid condition and progressively
drawing the stream of solids from the lower por
raising the temperature of the iluidized finely
tion of said reaction zone and withdrawing the
divided material by passing a heating gas iny
countercurrent ñow to said material at reduced 15 heating gas from the upper portion of said zone.
6. In the manufacture of cement the improve
velocity adjusted to maintain a dense turbulent
ment which comprises continuously passing lime
body of said solid materials to 1400" C., with
and Vclay materials used in the manufacture of
drawing the finely divided material which has
grinding to a line powder.
,
provements which comprise grinding limestone
a series of enlarged reaction zones, passing a
heating gas in countercurrent ilow with said nne
to a iine powder, fluidizing the limestone by
ly divided material as it passes into a first reac
3. In the manufacture of cement, the im
tion zone, passing a heating gas through the
blowing with continuously ñowing gas, raising
the temperature progressively by passing a heat 25 said reaction zones at a temperature suiiìciently
ing gas in countercurrent flow to said material at
reduced velocity adjusted to maintain a dense
turbulent body of said solid materials to 1000° ,
C. to remove ñrst the-moisture and then the car
high to maintain a temperature of 1400“ C. in`
the last reaction zone, and 1000° C. in the first
reaction zone, the said heating gas passing up
wardly to the. said reaction zones in counter
bon dioxide, mixing the residual fluidized powder 30 current ilow to the said material and at a re
duced velocity adjusted to maintain a dense tur
with clay and raising the temperature to about
bulent body of solid material within said zone,
1400“ C. to clinker the ñnely divided material,
maintaining said solid material in contact with
separating the clinkers and grinding to a finely
divided powder.
'
_
4. In the manufacture of cement, the im
said heating gas for a period of time sufiicient
35 to first drive oiî the moisture, then the carbon
provements which comprise grinding limestone
dioxide and finally to clinker the finely divided
and clay to a tine powder, blowing the finely
material in the last reaction »zone where a tem
perature of 1400° C. is maintained, and continu
divided mixture of limestone and clay with a con
ously withdrawing, in the last reaction zone,
tinuously ñowìng volume of gas suiilcient to fluid
ize the said mixture and progressively raising 40 cement and the heating gas from the upper part
of the ñrst reaction zone.
the temperature of the finely divided fluidized
7. In the manufacture of cement according
mixture of limestone and clay by passing a heat
to claim 6 the heating gas is contacted with .
ing gas in countercurrent ñow to said material at
the clinkered material being withdrawn from the
reduced velocity adjusted to maintain a dense
turbulent body of said solid materials to first 45 last reaction zone before passing into the last
separate the moisture, second, Áthe carbon diox
ide and third, to clinker the residual ñne mate
rial and grinding the clinkers to a ilne powder.
reaction zone.
.
BRUNO E. ROETHELI.
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