Year: 1898

page_text: We, CHRISTOPHER JOSEPH WHITTAKER and WALTER CHARLES BRYANT, both
of Globe Chemical Works, Church, in the County of Lancaster, Chemical Manu-
facturers, do hereby declare the nature of this invention to be as follows;-
-
This invention relates to the well known method of treating or purifying
sewage which consists in passing the sewage through filter beds, so as to allow of
the growth of a certain species of bacteria. Air which is necessary to the growth
of the bacteria being caused to pass through the filters at the same time.
Heretofore it has not been possible to work this process to the greatest advan-
tage, because the temperature of the sewage is too low to allow of the develope-
ment of the bacteria at the fullest activity for purification purposes.
Now our invention consists in so treating the sewage that the temperature
thereof is maintained during purification and filtration at the degree most
advantageous to the greatest activity of the bacteria.
For this purpose we heat the sewage just before passing on to the filters by
causing such sewage to flow over heated surfaces, or by injecting heated fluids
thereinto or by passing the sewage in a shower through heated air or in any other
convenient way. We prefer to heat the sewage to a temperature of about 70° Fahr.
The heated sewage in passing through the filters heats them, and also the air
admitted for oxidation to the proper temperature so that there are no cold surfaces
or fluids to retard the growth of the bacteria. Instead of the sewage being heated
before passing on to the filters, the said filters may be heated by means of pipes
or flues through which heated fluids are caused to pass thereby heating the sewage
and air passing through the filters, or the air before passing through the filters
for oxidation may be heated, such air afterwards heating the filters and also the
sewage in contact with which it pass.
Live steam may also be injected into the filters by which means the filter beds
and the sewage flowing through them are raised to the required temperature. And
at the same time the steam may be caused to carry with it the requisite amount
of air to insure the fullest growth of the purifying bacteria.

page_text: facturers, 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, reference being had to the accompanying drawings:
This invention relates to the well known method of treating or purifying
sewage which consists in passing the sewage through filter beds, so as to allow of
the growth of a certain species of bacteria, air which is necessary to the growth
of the bacteria, being caused to pass through the filter beds at the same time.
Heretofore it has not been possible to work this process to the greatest advan-
tage because the temperature of the sewage is to low to allow of the develop-
ment of the bacteria at the fullest activity for purification purposes.
Now our invention consists in so treating the sewage that the temperature
thereof is maintained during purification and filtration at the degree most
advantageous to the greatest activity of the bacteria.
For this purpose we heat the sewage just before passing on to the filters by
causing such sewage to flow over heated surfaces, or by injecting heated fluids
thereinto or by passing the sewage in a shower through heated air, or in any other
convenient way. We prefer to heat the sewage to a temperature of about 700 Fahr.
The heated sewage in passing through the filters heats them, and also the air
admitted for oxidation, to the proper temperature so that there are no cold surfaces
or fluids to retard the growth of the bacteria.
Live steam may also be injected into the filters by which means the filter beds
and the sewage flowing through them are raised to the required temperature. And
at the same time the steam may be caused to carry with it the requisite amount
of air to insure the fullest growth of the purifying bacteria.
DESCRIPTION OF THE DRAWINGS,
e are
Fig. 1 is a sectional view of a sewage filter and illustrative of the method of
carrying our invention into practice. are the walls of the filter. is the filter
bed of loose stones, coke, or other convenient material resting on the perforated
false bottom and offering a large surface for the sewage to flow over.
perforated pipes through which the sewage is sprinkled or sprayed on to the filter
bed. is a pipe through which steam is injected into the sewage passing along
the supply pipe e to the distributing pipes ". By means of the steam the sewage
is heated to a temperature at which the aerobic bacteria in the sewage can
develope in the filter bed to their fullest purifying activity. This temperature we
find is about 70° Fahr. but if in some cases it should be found that a higher or
lower temperature is beneficial such temperature may be readily obtained by
varying the supply of steam. The heated sewage flows through the pipes con
to the filter bed and trickles down in thin films over the surfaces of the material
which it heats to about the same temperature so that there are no cold surfaces
to retard the growth of the bacteria. The warmth of the filter bed causes a
current of air to ascend through the interstices of the material and afford the
necessary oxygen to the sewage. Such air also in passing up becomes heated to
the temperature of the filter bed. f is a pipe through which air is admitted under
the perforated bottom b¹. If sufficient air is not induced by natural draught,
mechanical means or a steam jet may be employed to force the necessary quantity
of air through the filter bed. In Fig. 1 g indicates a steam injector for forcing
air into the filter. When air forcing appliances are employed the space under
the perforated bottom must be made air tight, a water seal being employed to
prevent escape of air through the sewage outflow. When sewage has to be raised
to a height before passing on to the filter such sewage is conveniently heated by
means of the steam from the steam pump, or in an injector, used for raising the
sewage.
Instead of heating the sewage by steam as above described hot air may be
injected into it or such sewage may be caused to flow through pipes which are
heated in any convenient way. Fig. 2 shows an apparatus for heating the sewage.

page_text: In this arrangement the sewage before passing on to the filter flows through
pipes h which are exposed to the products of combustion from a furnace i. This
method is advantageous when it is not desired to dilute the sewage as is the case
to some extent when steam is injected thereinto.
Instead of or in addition to heating the sewage we may in some cases heat the
filter beds by injecting steam therein. Such steam condensing in the filter beds
heats them and also the sewage to the desired temperature. This method is con-
veniently carried into effect by means of a steam injector 7 as described under
Fig. 1. The steam passing through the injector serves to heat the filter beds and
at the same time to force through the beds the necessary air.
We do not confine ourselves to the particular arrangements above described for
carrying out our invention as it will be obvious that various means for heating
the sewage may be employed.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is:-
First. Heating sewage before passing it on to filter beds through which filter
beds air is caused or allowed to flow, substantially as and for the purpose set forth.
Second. The process of treating or purifying sewage consisting of heating the
sewage and then passing it through filter beds through which filter beds air is
also caused or allowed to flow substantially as and for the purpose set forth.
Third. Heating filter beds for sewage by means of steam injected thereinto
substantially as and for the purpose set forth.
Fourth. Utilizing a jet of steam employed for heating a filter bed as a means
for forcing the air necessary for aeration into such filter bed substantially as and
for the purpose set forth.
Dated this Third day of Novemba 1808