Improvements in or connected with the Boiling of Esparto or like Fibrous Material in the Manufacture of Paper.
Year: 1895

page_text: Date of Application, 5th Apr., 1895-Accepted, 11th May, 1895
COMPLETE SPECIFICATION.
Improvements in or connected with the Boiling of Esparto or like
Fibrous Material in the Manufacture of Paper.
1, JAMES PORTEUS CORNETT of Claxhengh near Sunderland in the County of
Durham, Paper Mill Manager, do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention relates to improvements in or connected with the boiling of
esparto or the like fibrous material in the manufacture of paper.
In the ordinary processes of boiling esparto and other paper-making fibres it is
usual to utilize the spent or used, cooling waters and wash waters in making up
succeeding hot washes or diluting strong leys, but for this purpose such used or
spent liquors are temporarily conveyed to a receiver or other vessel where much
loss and waste of heat occurs.
In ordinary processes also it is usual to utilize the blow off steam from the high
pressure boilings but such exhaust steam has hitherto only been utilized and made
valuable in keeping up or raising the temperature of liquors in outside receivers as
above described.
Now by my improved process I arrange a series of boilers in line or battery so
connected with each other that with the aid of pumps or other elevators as herein-
after described all cooling waters can be or are successively and immediately
conveyed over to the next succeeding boiler in the group or series to become hot
washes and all hot washes can be or are pumped or conveyed over into the next
succeeding boiler and so on in continuous manner.
Each boiler is filled successively with the same quantity of esparto or other fibre
and therefore naturally requires the same boiling and subsequent hot washing and
cooling consecutively until emptied and again filled in its successive order.
The number of boilers required is of course governed by the number of tons of
esparto or other fibrous material to be treated per day or week and the number of
hot washes and coolings desired.
At the same time as the cooling and washing waters are being passed forward, in
the process, to meet the newly boiled unwashed fibrous material (and thus cleanse
the same of all soda and soluble impurities) the blow off steam from the boilers
working under high pressure is conveyed direct into the boilers which are hot
washing and into the boiler which is being filled in with raw esparto or other fibre.
This is effected by having the blow off pipe of every boiler connected to one
common exhaust main and having this main again connected to each boiler just
below the high pressure steam inlet valve whereby any one or more high pressure
boilers can be made to convey their blow off steam to any one or more washing
boilers.
11.
1.
The number of coolings and of hot washings may be varied and the time occupied
in each operation may also be varied according to, the number of boilers in use and
the quantity of esparto etc. required to be treated.
The successive operations that will thus be carried on in one boiler to perform one
complete treatment or boiling, hot washing and cooling of the charge of esparto in
that boiler may thus be as hereinafter described and for the purposes of illustrating
the practical working, of my improved process, I prefer to describe the system
as applied to seven boilers, suitable for treating about 200 tons of esparto
per week.
Suppose one, boiler of the range to be empty, it will be charged with its
1.
proper

page_text: proportion of fresh caustic ley and say three tons of esparto and with the fresh ley
there may economically be added a measured quantity of spent or used ley from a
previous hot washing as hereinafter. described. The boiler will then be closed and
steam at say 45 lbs. pressure will be introduced to boil the mass. During boiling
in order to induce a vomit or circulation of liquor some steam will be allowed to
blow off into the exhaust main and after boiling the requisite time the whole of the
steam will be blown off into the same main. When the pressure is sufficiently
reduced the spent or used ley will be run off to the soda recovery department. The
lid will have now been removed from the boiler and by means of suitable pumping
or elevating machinery, pipes and connections as hereinafter described, the boiler
will have pumped into it at its upper lid its first hot wash from a preceding boiler
and simultaneously it will have injected into it, by an auxiliary pipe connected with
the main exhaust pipe, low pressure steam, which steam will have come direct from
the boiler or boilers being boiled under high pressure and blowing off into the main
exhaust pipe.
The first hot wash will thus be boiled in the boilers by low pressure steam and,
after a certain time, part of the ley in the boiler will, as before, be run off to the
soda recovery department, the remainder being pumped to a succeeding boiler to
dilute the fresh strong caustic liquor.
The boiler (whose treatment I am describing) will now have pumped into it at its
upper lid a second hot wash which will consist of all the hot wash from a preceding
boiler and this second hot wash will now be boiled by low pressure steam from the
exhaust main as just described. The second hot wash will now be pumped on to a
succeeding boiler and a cooling water will now be introduced from a preceding
boiler and be allowed to lie or steep without circulation. After this steeping or
soaking is over the first cooling water will be pumped off to a succeeding boiler.
The grass will now receive its second cooling water from a preceding boiler and
this cooling water will be actuated by a circulating pump which will draw off the
charge from the boiler bottom and deliver it again into the top of the same boiler
and after this circulation has progressed a sufficient time it will be stopped and the
resulting liquor will be pumped off to a succeeding boiler. Now the third and
final cooling charge consisting of cold fresh water from a water main or otherwise
will be run into the boiler to further cool the grass or fibre and this again will be
circulated within the boiler as just described above. This third cooling charge will
then be pumped off to a succeeding boiler when the esparto in the boiler whose
treatment has been described will be ready for emptying and further treatment by
breaking in the well known manner.
It will thus be seen that each charge of grass or fibre receives in each boiler two
hot washings and three cold washings, after the ordinary boiling under high pressure
steam.
I will now proceed to explain the apparatus for effecting the above described
purposes with reference to the accompanying drawings in which
Figure 1 (Sheets 1 and 2) shows in front elevation a complete battery of seven
boilers arranged to work as above described. Figure 2 shows an end view,
Figure 3 a plan at top of boiler and Figure 4 a plan on line X Y at boiler bottom
and in the following description like marks of reference designate like parts.
Referring to the drawings, the boilers are marked 1, 2, 3, 4, 5, 6 and 7. One
outlet pipe 8 at the bottom of each boiler serves for the following purposes (1) for
running off ley to the soda recovery. works, (2) as a suction pipe for the circulating
pump at 9, (3) as a suction pipe for the transfer pump at 10, (4) as a steam inlet to
the boiler. S is the high pressure steam pipe in each case. E is the main exhaust
pipe into which the boilers when blowing off exhaust through stand pipe S¹ and
pipe E' fitted with a cock 11. Each high pressure steam pipe S is connected below
its steam stop valve V with the main exhaust pipe E by a low pressure steam
pipe 12 fitted with a valve 13.
At each boiler bottom (see Figure 4) there is the following arrangement:-The
pipe 8 has a branch 14 with valve 15 leading to the soda recovery works via pipe 14

page_text: Off the branch 14 a branch 16 leads as shown to two valves 17 and 18, 17 leading
to the suction pipe 19 of the circulating pump 9 and 18 leading to the suction
pipe 20 of the transfer
10.
pump A further branch 21 from pipe 8 is connected
with the steam supply pipe S and by the arrangement of high pressure steam stop
valve V and low pressure steam pipe 12 with its valve 13 it will be clear that the
boiler can be supplied through pipe 8 either with high pressure steam via valve V
or, when V is closed, with low pressure steam through valve 13 from the main
exhaust pipe E.
From the circulating pump 9, a delivery main 22 is led as shown and fitted with
stop valves 23 opposite each boiler. A flexible hose pipe F serves to connect these
valves with the open lids of the boilers.
From the transfer pump 10 a delivery main 24 is led as shown and connected by
a branch 24 to the stand pipe S¹ a stop valve 25 being provided as shown in each
case.
26 is the fresh cold water supply pipe.
One end, e.g. E, of the main exhaust pipe E will be led away to a hot water tank
and furnished with a stop valve so that when not otherwise required the low
pressure steam may be utilized in this manner.
For the sake of illustrating the practical working of the improved system,
suppose for example, that No. 4 boiler is empty and ready for charging as above
described, Nos. 2 and 3 will be boiling under high pressure steam supplied from
pipe S. No. 5 will be having its third or final fresh cold cooling water circulated
within itself by means of pump 9 and its pipes arranged as described. No. 6 will
be having its second cooling water which may have been the first cold wash of No. 5.
No. 7 will be having its first cooling water which may have been the second cooling
water of No. 6 and No. 1 will be having its first and second hot washes which may
have been respectively the second hot wash and first cooling water of No. 7, No. 1
first hot wash being the remainder of the second hot wash of No. 7, which will not
be required to make up the caustic ley of No. 5.
The next cycle of operations will be as follows:-No. 5 will be empty and ready
for charging, Nos. 3 and 4 will be boiling under high pressure steam supplied from
pipe S. No. 6 will be having its third or final cooling water made up of cold fresh
water and circulated within itself by means of pump 9 and its pipes arranged as
described; No. 7 will be having its second cooling water which may have been the
first cooling water of No. 6; No. 1 will be having its first cooling water which may
have been the second cooling water of No. 7 and No. will be having its first and
second hot washes which may have been respectively the second hot wash and first
cooling water of No. 1, No. 2 first hot wash being the remainder of the second hot
wash of No. 1 which will not be required to make up the caustic ley of No. 6.
From the arrangement described it will thus be seen that continuity of action or
working is attained in the chargings and subsequent boilings and washings of the
grass or other fibrous material in the boilers as well as in the transference and
circulation of the liquors for washing purposes the working result of my improved
system being a maximum recovery of soda with a minimum quantity of water and
steam and consequent great economy.
I wish it to be understood that I have described and shown in the drawings those
parts which I consider essential to a proper understanding of my invention and any
pipes or apparatus not shown or described though possibly necessary for the
practical working are not part of my invention.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In the working of fibre boilers in the manufacture of paper arranging in
connection therewith a main exhaust pipe to receive the exhaust steam from the
boilers blowing off and to supply the low pressure steam thus collected to the main
steam supply pipes so that the boilers can be supplied either with high pressure

page_text: steam via valve V for the main boiling or with low pressure steam vid valve 13 for
the subsequent hot washings, the several parts being arranged and adapted to work
substantially as and for the purposes herein set forth.
2. In the working of fibre boilers in the manufacture of paper connecting the
base of each boiler in a battery by branch pipes and valves with double suction
pipes leading to circulating and transferring pumps whose delivery pipes are iu
connection with the upper parts of the boilers so that the liquor contents of any
boiler can be circulated within itself by the circulating pump for the required length
of time and then transferred by the transfer pump to another boiler substantially as
and for the purposes herein set forth.
3. In the working of fibre boilers in the manufacture of paper connecting the
boiler tops together by branch steam pipes leading to a common exhaust pipe and
connecting the latter to the steam main so that high pressure or low pressure
boilings may be effected within the boilers and connecting the boiler bottoms to the
suction pipes of circulating and transferring pumps adapted respectively to circulate
the ley through the boiler and to transfer it from boiler to boiler for the purpose of
washing the fibre, the hot washings so transferred being boiled by low pressure
steam obtained from the main exhaust pipe, the several parts for effecting these
several purposes being arranged and adapted to work substantially as herein set
forth.
4. The improved system of boiling esparto or like fibrous material consisting in
the general arrangement of steam and liquor or ley distribution to and in and from
the boilers the parts being disposed and adapted to work substantially as and
for the purposes herein set forth.
Dated this 3rd day of April 1895.
A. CRAWHALL CHAPMAN,
3, St. Nicholas Buildings, Newcastle-on-Tyne, Patent Agent.