IMPROVEMENTS IN AND APPER- TAINING TO THE PROCESS OF AND APPARATUS FOR FILTERING SACCHARINE AND OTHER SOLUTIONS OR LIQUIDS
Year: 1879

page_text: LETTERS PATENT to William Phillips Thompson, of the Firm of W. P.
Thompson and Co., of 323, High Holborn, in the County of Middlesex, and
6, Lord Street, Liverpool, in the County of Lancaster, Patent Agents and
Consulting Engineers, for the Invention of "IMPROVEMENTS IN AND APPER-
TAINING TO THE PROCESS OF AND APPARATUS FOR FILTERING SACCHARINE AND
OTHER SOLUTIONS OR LIQUIDS." A communication from abroad by George
Childs Wilson Belcher, of St. Louis, in the State of Missouri, Sugar Refiner.
PROVISIONAL SPECIFICATION left by the said William Phillips Thompson
at the Office of the Commissioners of Patents on the 28th May 1879.
WILLIAM PHILLIPS THOMPSON, of the Firm of W. P. Thompson and Co., of
323, High Holborn, in the County of Middlesex, and 6, Lord Street, Liverpool, in
the County of Lancaster, Patent Agents and Consulting Engineers. "IMPROVE-
MENTS IN AND APPERTAINING TO THE PROCESS OF AND Apparatus for FILTERING
SACCHARINE AND OTHER SOLUTIONS OR LIQUIDS." A communication from abroad
by George Childs Wilson Belcher, of St. Louis, in the State of Missouri, Sugar
Refiner.
The objections to the ordinary method of filtration are:-First. The labour and
expense involved in the frequent removal and cleansing of the bags, the interruption
in their use, and incidental wear and tear; and, Second. The loss of bags and
sheaths by breakage from over pressure.
Third. The injury of the liquor or
expense of refiltration caused by the discharge of feculent matters and unfiltered
liquor. Fourth. The large number of bags required for use.
The purpose of my Invention is to remedy these several objections, and though
relating especially to the filtration of sugar solutions commonly known as sugar
liquors, it is capable of use in the filtration of other liquids.
For this purpose I construct a cylinder, preferably of boiler iron, of sufficient
strength to resist considerable artificial internal pressure.
I suspend the filtering bags by their bottles within this cylinder, and insert

page_text: within each of these bags a perforated mecatie sus, preten
closed at the bottom or nearly so, open at the top, and firmly secured in the top of
the aforesaid cylinder.
The construction and arrangement is more fully shown by reference to the
accompanying Drawing, in which Fig. 1 shows the above mentioned cylinder 5
having a portion removed, as indicated by the broken line, to show the internal
arrangement.
The above mentioned perforated tubes are shown as 1, 1, Fig. 1. The filtering
bag is omitted from one of the tubes here shown in order to exhibit it more fully.
One of the filtering bags arranged -in position for use is shown as 3, Fig. 1, the 1
perforated tube within it being shown by dotted lines.
As a precaution against breakage the bag is inade longer than the tube, as shown
in the Drawing. The pipe for the admission of the sugar liquor to this cylinder is
shown as 4, and a man hole as 5.
Fig. 2 is a top view of the cylinder showing the ends of tubes 1, 1.
Fig. 3 shows on a larger scale a cross section of the upper portion of the tube 1,
as arranged in the bottle 2.
Fig. 4 shews an improved form of bottle which may be substituted for bottle,
Fig. 3.
The operation is as follows:-
The sugar liquor enters the cylinder A under pressure through the pipe at 4, and
is forced by this pressure through the filtering bags, which are sustained against
the pressure by their internal inetallic tubes 1, 1. The filtered liquor passes out
through the tops of these tubes, and thence through pipe 8 or by any other
convenient communication to its reservoir. The pressure upon the liquor in
cylinder A inay be obtained by any of the known methods. The inventor prefers
a force pump or other power capable of being regulated at the will of the operator,
according to the quality or condition of the liquor, but a head obtained from an
elevated reservoir may be used.
The use of the pressure resisting cylinder A and supporting tubes 1, 1, thus
enable one to pass the liquor rapidly through the filtering bags without danger of
breakage. It effects a great saving in bags, dispenses entirely with the sheaths,
and avoids the mischief resulting from the discharge of feculencies into the
reservoir for filtered liquor. The feculent matter removed by filtration is retained
on the outside of the bag instead of within it, and is hence much easier of removal.
In order to wash the bags the inventor passes steam or streams of heated water
into the tubes 1, 1, through their tops. They pass through the bags in the opposite
direction from the sugar liquor, and hence readily and rapidly remove any feculent
matter that adheres to the exterior of the bags. The water may pass out of the
cylinder A through the pipo 9, which also serves to draw off the unfiltered liquor
and residuum when the filtration ceases. A large saving in time, labour, and
expense of washing is thus effected.
The bottle for suspending the filtering bags may be of the ordinary form, as
shown in Fig. 3, and attached to the top of the cylinder by nipple 6, as seen in
Fig. 3, permanently screwed into said top.
The inventor attaches by solder or otherwise to tubes 1, 1, sleeves 7, seen in
Figs. 3 and 4, cutting a thread around this sleeve and a corresponding thread upon
the inside of the nipple 6, as shown in Fig. 3. By screwing this sleeve into the
nipple 6 the tube is firmly secured against pressure in either direction.
The inventor prefers a modification in the form of the bottle which better adapts
it to the change in the direction of pressure upon the bag.
This modified form is shown in Fig. 4.
After swelling sufficiently to afford a support for the bag the bottle is made to
converge, as shown in Fig. 4, thus presenting a surface less likely to tear the bag
when forced against it by the external pressure employed in this method of

page_text: Mention has been made of the external casings used by the inventor in which
the liquor is applied under prossure to the filtering bags as pressure cylinders, this
being a convenient form in which to construct them; but it is obvious that their
shape is not essential and may be varied if desired. So, also, they may be inverted
or otherwise varied in position though there are obvious advantages in having the
discharge at the top. The tubes may also be varied in shape or formed of a series
of bars, provided they continue to serve the purpose of sustaining the bags against
the external pressure used in the operation, and at the same time allow the filtered
liquor to escape through them.
Perforated tubes might be constructed of such dimensions as to embrace the
filtering bags, and the liquor be forced outward instead of inward; but this method
is exposed to several objections as compared with that heretofore described. The
position of pipes for admitting and discharging the liquor, as shown in the Drawing,
may be varied at pleasure.
A section of steam pipes, such as is commonly used in the present style of bag-
filter casings, may be also used in the pressure cylinder or casing for the purpose of
warming, either directly or indirectly, the bags and the solutions contained within
the bags, and thereby assisting the filtration of the liquor and the cleansing of the
bags.
The inventor is aware that it is not new to cleanse filters by a stream or current
in reverse direction to that which has been filtered. A well known instance is the
mode of cleansing water filters.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent nieu by
the said William Phillips Thompson in the Great Seal Patent Office on the
27th August 1879.
WILLIAM PHILLIPS THOMPSON, of the Firm of W. P. Thompson and Co., of
323, High Holborn, in the County of Middlesex, and 6, Lord Street, Liverpool, in
"IMPROVE-
the County of Lancaster, Patent Agents and Consulting Engineers.
MENTS IN AND APPERTAINING TO THE PROCESS OF AND APPARATUS FOR FILTERING
SACCHARINE AND OTHER SOLUTIONS OR LIQUIDS." A communication from abroad
by George Childs Wilson Belcher, of St. Louis, in the State of Missouri, Sugar
Refiner.
This Invention relates especially to the filtration of sugar solutions commonly
known as sugar liquors, though it is capable of use in the filtration of other
liquids.
The apparatus now commonly in use for this purpose consists of a series of
filtering bags hung upon metallic bottles and enclosed in external bags, commonly
called sheaths, of smaller diameter and coarser texture than the said filtering bags,
and open at the bottom. These bags thus enclosed in their sheaths are suspended
in cases, usually several hundred in a single case, several thousand being required
for daily use in a refinery of average size.
The sugar liquor entors these filtering bags through their respective bottles,
All feculent
which are screwed directly or indirectly into the top of the case.
matter removed by this filtration is necessarily retained within the bags which
speedily become clogged. The weight of the liquor will no longer force it through
them, and additional pressure cannot be applied without danger of breaking them.
They must therefore be cleaned. For this purpose they must be removed from the
bottles by which they are suspended, washed, and wrung. They are of such shape
as to render it impracticable to turn them wrong side out while the feculent
matter is still in thein, and often have to pass through a series of washings and
wringings before they are again ready for use.
The weight of sugar liquor is such as to occasion frequent breakage of these bags
and their respective sheaths while in use, especially when they have began to clog.
The expense involved in the replacement of the bags and sheaths thus broken is
very considerable, amounting to several thousand dollars a year in refineries of the
average size; but the results of this breakage are in other ways more serious.
The feculent matter which has accumulated in the bags is carried at once into
the reservoir of filtered liquor, and the unfiltered liquor continues to flow through
the broken bag until the break is discovered and its course stopped. As it is
impracticable to constantly watch all the bags in use this flow will often continue
for some time. In any event the alternative is presented of passing on the liquor
to succeeding stages with the feculencies thus discharged still in it, or refiltering
the entire body of liquor with which these feculencies have been remixed.
The objectious to this method of filtration are:-First. The labour and expenses
involved in the frequent removal and cleansing of the bags, the interruption in
their use, and incidental wear and tear. Second. The loss of bags and sheaths by
breakage from over pressure. Third. The injury of the liquor or expense of refil-
tration caused by the discharge of feculent matters and unfiltered liquor. Fourth.
The large number of bags required for use.
The purpose of my Invention is to remedy these several objections.
For this purpose I construct a cylinder, preferably of boiler iron, of sufficient
strength to resist considerable artificial internal pressure.
I suspend the filtering bags by their bottles within this cylinder, and insert
within each of these bags a perforated metallic tube, preferably of brass or copper,

page_text: De bottom of nearly so, open at the top, and firmly secured in the top of
the aforesaid cylinder.
The construction and arrangement is more fully shown by reference to the
accompanying Drawing, in which Fig. 1 shows the above mentioned cylinder
having a portion removed, as indicated by the broken line, to show the internal
arrangement.
The above mentioned perforated tubes are shown as 1, 1, Fig. 1. The filtering
bag is omitted from one of the tubes here shown in order to exhibit it more fully.
One of the filtering bags are arranged in position for use is shown as 3, Fig. 1, the
perforated tube within it being shown by dotted lines.
As a precaution against breakage the bag is made longer than the tube, as shown
in the Drawing. The pipe for the admission of the sugar liquor to this cylinder is
shown as 4, and a man-hole as 5.
Fig. 2 is a top view of the cylinder showing the ends of tubes 1, 1.
Fig. 3 shows on a larger scale a cross section of the upper portion of the tube 1,
as arranged in the bottle 2.
Fig. 4 shows an improved form of bottle which may be substituted for bottle
Fig. 3.
The operation is as follows;-
The sugar liquor enters the cylinder A under pressure through pipe 4, and is
forced by this pressure through the filtering bags, which are sustained against the
pressure by their internal metallic tubes 1, 1. The filtered liquor passes out
through the tops of these tubes, and thence through pipe 8 or by any other
convenient communication to its reservoir. The pressure upon the liquor in
cylinder A may be obtained by any of the known methods. The inventor prefers
a force pump or other power capable of being regulated at the will of the operator,
according to the quality or condition of the liquor, but a head obtained from an
elevated reservoir may be used.
The use of the pressure resisting cylinder A and supporting tubes 1, 1, thus
enable one to pass the liquor rapidly through the filtering bags without danger of
breakage. It effects a great saving in bags, dispenses entirely with the sheaths,
and avoids the mischief resulting from the discharge of feculencies into the
reservoir for filtered liquor. The feculent matter removed by filtration is retained
on the outside of the bag instead of within it, and is hence much easier of removal.
In order to wash the bags the inventor passes steam or streams of heated water
into the tubes 1, 1, through their tops. They pass through the bags in the opposite
direction from the sugar liquor, and hence readily and rapidly romove any feculent
matter that adheres to the exterior of the bags. The water may pass out of the
cylinder A through the pipe 9, which also serves to draw off the unfiltered liquor
and residuum when the filtration ceases. A large saving in time, labour, and
expense of washing is thus effected.
The bottles for suspending the filtering bags may be of the ordinary form, as
shown in Fig. 3, and attached to the top of the cylinder by nipple 6, as seen in
Fig. 3, permanently screwed into said top.
The inventor attaches by solder or otherwise to tubes 1, 1, sleeves 7, seen in
Figs. 3 and 4, cutting a thread around this sleeve and a corresponding thread upon
the inside of the nipple 6. By screwing this sleeve into the nipple 6, as shown in
Fig. 3, the tube is firmly secured against pressure in either direction.
The inventor prefers a modification in the form of the bottle which better adapts
it to the change in the direction of pressure upon the bag.
This modified form is shown in Fig. 4.
After swelling sufficiently to afford a support for the bag the bottle is made to
converge, as shown in said Fig. 4, thus presenting a surface less likely to tear the
bag when forced against it by the external pressure employed in this method of
filtration.
Mention has been made of the external casings used by the inventor in which

page_text: the liquor is applied under pressure to the filtering bags as pressure cylinders, this
being a convenient form in which to construct them; but it is obvious that their
shape is not essential and may be varied if desired. So, also, they may be inverted
or otherwise varied in position, though there are obvious advantages in having the
discharge at the top. The tubes may also be varied in shape or formed of a series
of bars, provided they continue to serve the purpose of sustaining the bags against
the external pressure used in the operation, and at the same time allow the filtered
liquor to escape through them.
Perforated tubes might be constructed of such dimensions as to embrace the
filtering bags, and the liquor be forced outward instead of inward; but this method
is exposed to several objections as compared with that heretofore described. The
position of pipes for admitting and discharging the liquor, as shown in the Drawing,
inay be varied at pleasure.
A section of steam pipes, such as is commonly used in the present style of bag-
filter casings, may be also used in the pressure cylinder or casing for the purpose of
warming, either directly or indirectly, the bags and the solutions contained within
the bags, and thereby assisting the filtration of the liquor and the cleansing of the
bags.
The inventor is aware that it is not new to cleanse filters by a stream or current
in reverse direction to that which has been filtered. A well-known instance is the
mode of cleansing water filters.
Having now described and ascertained the nature of my said Invention as
communicated to me by my foreign correspondent, 1 wish it to be understood that
what I believe to be new and desire to claim under the herein before in part recited
Letters Patent is,―
First. The combination of a tight case, filtering bags within the case secured to
one head only, and stopping short of the other, a reinforcing tube having suitable
interstices, and mechanism for supplying the liquor to be filtered under pressure,
substantially as described.
Second. The combination of pressure cylinder, filtering bags secured to one head
thereof and stopping short of the other, and perforated metallic reinforcing tubes
within the bags, substantially as described.
Third. The combination of a tight case, filtering bags within the case secured to
one head and stopping short of the other, and mechanism for supplying the liquor
to be filtered under pressure, substantially as described.
Fourth. The combination of a tight casing, a series of independent filters
suspended therein, mechanism for forcing the liquor to be filtered through the filter
in one direction, and mechanism for passing the cleansing medium through the
filters in the reverse direction, as and for the purposes set forth.
Fifth. The combination of a pressure casing, a series of independent filters in a
common chamber therein, mechanism for forcing the liquor to be filtered into the
chamber of the casing through the filters and out through their delivery tubes, and
mechanism for passing a cleansing medium in through the filters, out into the
chamber of the casing, and through a suitable duct, disintegrating and carrying
with it the sediment or feculae previously deposited upon the outside of the filters,
substantially as described.
Sixth. The combination with filtering bags hung by one end only of perforated
reinforcing tubes secured at the end corresponding with the mouth of the bag and
free at the other end.
Seventh. The improved bottle for use in sugar filters formed with an outward
bulge or swell for the support of the bag, and from thence converging inwardly
and downwardly to the lower aperture, substantially as described.
Eighth. The improved bottle having the bulge and inward convergence in
combination with the filtering bag and reinforcing tube, substantially as and for
the purpose described.

page_text: Ninth. The combination of sloevod tube, nipple, and bottle with pressure casing A,
substantially as and for the purposes described.
Tenth. The combination of sleeved tube, nipple, and bottle with pressure casing
and the filtering bag suspended therein, as set forth.
Eleventh. The herein described method of cleansing the bags by forcing a stream
through them in the opposite direction from the filtration, substantially as and for
the purposes described.
In witness whereof, I, the said William Phillips Thompson, have hereunto set
my hand and seal, this Twenty-ninth day of July, in the year of our Lord
One thousand eight hundred and seventy nine.
W. P. THOMPSON. (L.S.)