Title of Invention

A METHOD AND A SYSTEM FOR REMOVAL OF SURFACE SCUM BY MEANS OF AN EXHAUST DEVICE

Abstract The invention relates to a method for removal of surface scum by means of an exhaust device (2) that exists in connection with a liquid basin (N), such as a settling tank, the exhaust arrangement comprising a first surface chute (2a), existing essentially in a crosswise direction with respect to a longitudinal direction (s) of the liquid basin, for removal of surface scum by means of an overflow means (2al), belonging to the liquid basin and being based on a continuous flow, by means of which the surface scum is being overflown in at least two successive phases, in the first phase from the fluid basin into a primary space (I) existing in the fluid basin, and in a second phase into a secondary space (II) from the primary space (I) situated further ahead in the fluid basin, from where it is being finally exhausted from the liquid basin by means of an exhaust assembly (P) for the surface scum, such as by one or more exhaust pipes, or channels, and a second surface chute (2c) for removal of liquid, being processed in the liquid basin, such as clarified water. Overflow of the surface scum existing in the primary space (I), to the secondary space (II) is being controlled particularly in order to minimize the amount of water drifting together therewith by adjusting the level (h1) of the liquid in the primary space (I) by means of a flow balancing assembly (2a2), connecting the primary space (I) and the second surface chute (2c), and/or by using an adjusting device (LL) existing in the wall defining the primary space (I) and the secondary space (II), and in that the scum on the surface of the liquid basin (N) is overflown to the primary space (I) by means of a downwardly slopping guide surface (V) to maintain a laminar flow of the surface scum.
Full Text Method and arrangement for removal of surface scum
The invention relates to a method for removal of surface
scum in an apparatus, which comprises at least a first
surface chute arrangement that exists in a liquid basin
and which is meant for removal of surface scum.
A traditional solution in the purpose described above
and particularly in square shaped basins is such, that
the fluid processing apparatus, such as a clarification
basin or like, comprises usually a special kind of a
scraper bar arrangement, which has several scraper bars,
existing one after the other in the longitudinal
direction of the basin, and movement means for moving
the same, such as two chains, being placed parallelly
and being driven by means of a drive wheel and idle wheel
assembly, in connection with which the scraper bars are
fastened removeably particularly in order to make easier
the service and maintenance of the scraper bar
arrangement. The type of scraper bar arrangements
mentioned above are nowadays being used e.g. in
connection with clarification basins in a way that the
scraper bar/bars is/are transferred by chains, moving
at opposite side or intermediate walls of the basin,
alternatively on the surface and at the bottom of the
basin, scraping sludge existing at the bottom to a sludge
pocket while passing along the bottom, and, respectively
guiding material existing on the surface to a collecting
chute, which goes crosswise through the basin, while
passing on the surface. There are also scraper bar
arrangements, in which the bars are being moved e.g.
by means of a carriage, moving above the basin, or e.g.
by hydraulic arrangements. Also the shape of the basin
may be in practice almost of whatever form.
In this connection, the surface scum is traditionally
exhausted in a so to speak indirect manner, whereby the
scrapers while passing on the surface, guide the
material on the surface towards the collecting chute
in a so called free-drifting manner. The collecting
chutes, being used in this connection, are usually
mechanically operated "suction chutes", which are being
rotated from time to time around a longitudinal axis
to a position, in which the surface scum is being "gulped"
inside the same in order to lead it subsquently away
from the liquid basin. On the other hand, in this
connection a suction chute is used also, which has a
moveable front wall, the operating principle of which
is, however, in practice the same as described above.
A problem related to this kind of suction chutes is the
fact that they take along too much surface water, which
can thus drift along with the surface scum furthermore
to the exhaustion channel of the surface scum. Also the
bearing of such rotating suction structures to the walls
of the basin is very difficult to carry out structurally,
which is why among other things leaks are caused. In
addition to the above, the suction chutes easily tend
to get jammed among other things due to temperature
differencies. The type of mechanically operated chute
arrangements described above require naturally also
operating devices and automation in order to move the
chutes, which is why this kind of implementations
require a very dense service and maintenance in order
to keep them operable. Furthermore, a problem in
practice related to this kind of solutions is due to
exessive surface scum that gets collected on the surface
of the liquid basin, together with which also other
impurities may get collected. It is thus very usual that
also organic processes may take place in the surface
scum among other things in the form of algal growth.
It is the aim of the method according to the present
invention to achieve a decisive improvement in the
problems described above and thus to raise essentially
the level of prior art. In order to carry out this aim,
the method according to the invention is mainly
characterized by that the surface scum is being
exhausted by means of an overflow arrangement, belonging
to the first surface chute arrangement and being based
on a continuous flow, by means of which the surface scum
is being overflown in at least two successive phases.
It should be noted in this context that the surface water
bringing the surface scum to the chute is just the same
water, which is being moved to the overflow chutes, being
placed after the suction chute, or to exhaust pipes,
existing underneath the surface.
As the most important advantage of the method according
to the invention is first of all the fact that by means
of an overflow arrangement, being based on a continuous
flow with two phases, it is possible to eliminate all
the problems related to moveable arrangements or
corresponding mechanically operated exhaustion chutes,
the most important thing thus being the possibility to
minimize the amount of the surface water drifting along
with the surface scum. In addition to the above, the
area from which the surface scum is being removed can
be adjusted by controlling the height of the primary
space, belonging to the overflow arrangement, with
respect to an overflow edge in the secondary space. This
is enabled by using a flow balancing assembly, which
comprises one or more pipes, channels or\like, being
connected to the arrangement removing clarified liquid
from the primary space, and adjusting means for
adjustment of the level of the liquid in the primary
space. Furthermore the method according to the invention
may be utilized also by an arrangement, which is totally
independent on the level of the liquid basin, by enabling
the overflow arrangement to settle freely in the
direction of height along the level of the liquid basin
e.g. by using floating arrangements.
In the dependent claims related to the method according
to the invention advantageous embodiments of the method
according to the invention have been presented.
The invention relates also to an arrangement for removal
of surface scum operating according to the method, which
has been defined in greater detail in the preamble of
the independent claim related to the same. The
arrangement according to the invention is for its part
characterized by what has been presented in the
characterizing part of the independent claim related
to the same.
As the most important advantages of the arrangement
according to the invention may be mentioned simplicity
and efficiency of its operating principle and use,
whereby thanks to the same it is furthermore possible
to avoid also the problems involved with traditional
mechanical solutions. In spite of a continuous flow
being exploited in the arrangement, with it it is also
possible to eliminate removal of excessive liquid along
with the surface scum. This is made possible first of
all by means of an overflow arrangement, based on a two
staged overflow, which comprises a primary space and
a secondary space. On the other hand the final removal
of the surface scum from the secondary space may be
furthermore carried out in a totally controlled manner
by exploiting a flow balancing assembly, by means of
which the overflow of the surface scum from the primary
space to the secondary space is being controlled in order
to minimize the amount of liquid drifting along with
the surface scum. In this way, it is possible to adjust
the level of the primary space as desired e.g. by
changing the discharge height of the flow pipe belonging
to the flow balancing arrangement or by using a turnable
flap structure in connection with an intermediate wall,
separating the primary space and the secondary space
from each other.
Thanks to the arrangement according to the invention,
it is thus possible to minimize significantly the
installation, service and maintenance measures related
to traditional solutions, the arrangement operating
independently and optimally in a way that excessive
surface scum may not get collected in the liquid basin.
On the other hand, thanks to the operating principle
based on a continuous flow, the surface scum is also
continuously on the run, which is why it may not become
solid. Also formation e.g. of algal growth therewith
is prevented.
Advantageous embodiments of the arrangement according
to the invention have been represented in the dependent
claims related to the same.
In the following description the invention is being
depicted in greater detail with reference to the
appended drawings, in which
in figures 1, 2 and 3
is shown as a perspective view, a side view
and an end view one advantageous arrangement
operating according to the method according
to the invention,
in figures 4, 5 and 6
is shown as a perspective view, a side view
and a front view one alternative embodiment
in respect to the one mentioned above, and
in figure 7
is shown furthermore a longitudinal cross-
section of a particularly advantageous
integral overflow arrangement.
The invention relates to a method for removal of surface
scum in an apparatus, which comprises at least a first
surface chute arrangement 2a that exists in a liquid
basin N and which is meant for removal of surface scum.
Surface scum is being exhausted by means of an overflow
arrangement 2al, belonging to the first surface chute
arrangement 2a and being based on a continuous flow,
by means of which the surface scum is being overflown
in at least two successive phases on the principle shown
e.g. in figures 1, 4 and 7.
Especially with reference to figures 4-6 the apparatus
comprises furthermore a scraper bar arrangement 1 that
moves in the liquid basin, such as a settling tank or
like, and that is meant for scraping of material existing
in the liquid basin to an exhaust arrangement 2, existing
in connection with the liquid basin and comprising in
addition to the first surface chute arrangement 2a,
existing essentially in a crosswise direction with
respect to the longitudinal direction s of the liquid
basin, a bottom chute arrangement, existing at the
bottom of the liquid basin and that is meant for removal
of bottom sludge, and furthermore a second surface chute
arrangement 2c for removal of liquid, being processed
in the liquid basin, such as clarified water. As an
advantageous embodiment the scraper bar arrangement 1
consists of one or more scraper bars la, existing one
after the other in the longitudinal direction s and being
adapted moveable by means of drive elements lb, such
as one or more transmission chains 1b2 or the like, being
driven through the intermediary of a drive wheel and
idle wheel arrangement 1b1 or in a like fashion, in
connection with which the scraper bar/bars la is/are
being fastened. With reference e.g. to figures 1 and
4, the surface scum is being exhausted by means of the
overflow arrangement 2al in a way, that the scum on the
surface of the liquid basin is being overflown from the
liquid basin N in a first phase by means of a downwardly
sloping guide surface V to a primary space I, from which
the surface scum is being overflown subsequently in a
following phase to a primary space II, from which it
is being exhausted finally from the liquid basin N by
means of an exhaust assembly P for the surface scum,
such as by one or more exhaust pipes, channels or like.
The meaning of the downwardly sloping guide surface is
to keep the flow of the surface scum, taking place along
the same, as laminar as possible, so that it will remain
on the surface in the primary space I.
As a further advantageous embodiment, the overflow of
surface scum from the primary space I to the secondary
space II is being controlled particularly in order to
minimize the amount of water drifting together therewith
by means of a flow balancing assembly 2a2, which
comprises one or more flow pipes 2a2a, channels 2a2a'
or like, being connected to the arrangement removing
clarified liquid from the primary space I, such as the
second surface chute arrangement 2c, and adjusting means
2a2b for adjustment of the level h1 of the liquid in
the primary space I by means of an adjusting device LL
existing in the wall defining the primary space I and
the secondary space II or by an adjusting sleeve,
existing at the end of said flow pipe, channel or like,
which alters the discharge height hv of said flow pipe,
channel or like. In this way it is possible to discharge
surface liquid drifted from the liquid vessel directly
to the arrangement removing clarified liquid.
The invention relates also to an arrangement for removal
of surface scum in an apparatus of the type described
above, the first surface chute arrangement 2a of which
comprises an overflow arrangement 2al, being based on
a continuous flow for exhaustion of surface scum so that
it is being overflown in at least two successive phases.
Especially with the advantageous embodiments shown in
figures 1, 4 and 7, the overflow arrangement 2al
comprises a primary space I provided with a downwardly
sloping guide surface V in order to get the scum on the
surface of the liquid basin to get overflown in a first
phase and a secondary space II in order to exhaust
surface scum, being overflown in a second phase from
the primary space I, finally from the liquid basin N
by means of an exhaust assembly P for the surface scum,
such as by one or more exhaust pipes, channels or like.
Furthermore as an advantageous embodiment, the
arrangement comprises a flow balancing assembly 2a2 in
order to control the overflow of the surface scum from
the primary space I to the secondary space II
particularly in order to minimize the amount of water
drifting together therewith, which e.g. according to
figures 2, 5 and 7 comprises one or more flow pipes 2a2a
channels 2a2a' or like, being connected to the
arrangement removing clarified liquid from the primary
space I, such as the second surface chute arrangement
2c, and adjusting means 2a2b for adjustment of the height
h1 of the level of the liquid in the primary space I
by means of an adjusting device LL existing in the wall
defining the primary space I and the secondary space
II or by an adjusting sleeve, existing at the end of
said flow pipe, channel or like, which alters the
discharge height hv of said flow pipe, channel or like.
In this context it is also possible to use e.g. according
to figure 2, filtering arrangements ss e.g. in the flow
pipe 2a2a, by means of which entering of solid material
to a so a called clear water side can be eliminated.
In the advantageous embodiment shown particularly in
figure 7, the primary space I, the secondary space II,
the flow balancing assembly 2a2 and at least a part of
the second surface chute arrangement 2c, all belonging
to its overflow arrangement 2al, are arranged as an
integral entirety, in which the primary space I, the
secondary space II, said part of the second surface chute
arrangement 2c and the flow channel 2a2a', belonging
to the flow balancing assembly, all being placed one
after the other in the longitudinal direction s, are
limited from each other by mutual walls w.
Furthermore as an advantageous embodiment with
reference to the embodiment shown in figures 1-3, the
secondary space II is placed, when viewed in the
longitudinal direction s of the liquid basin,
transversely after the primary space I, so that it
descends e.g. as shown in figures 1 and 3 towards the
exhaust assembly P of the surface scum, when viewed in
the crosswise direction of the liquid basin.
As an alternative solution with respect to the above,
with reference to the embodiment shown in figures 4-6,
the secondary space II is placed e.g. according to figure
6 at the end of the primary space I, when viewed in the
crosswise direction of the liquid basin.
Furthermore as an advantageous embodiment, the overflow
arrangement 2al for surface scum is arranged e.g. on
the principle shown in figures 1,2, 4 and 5 to settle
freely in a direction of height h along with the surface
of the liquid basin by using floating structures KR or
like.
Deviating from the embodiments shown in the appended
drawings, it is naturally possible to couple a flow pipe
2a2a, channel 2a2a' or like, belonging to the flow
balancing assembly 2a2, with a collecting
channel/tunnel or like that removes clarified liquid
from the liquid basin in a centralized manner.
It is clear that the invention is not limited to the
embodiments presented or described above, but it can
be modified within the basic idea of the invention in
very many ways depending on the needs of any given time.
Thus, the invention also relates at its widest to basins,
which do not necessarily have any kind of a scraper bar
arrangement and/or, in which the surface scum is being
transferred by whatever arrangement toward the suction
chute. There exists naturally a large amount of
different kinds of scraper bar structures, in addition
to which it is possible to use in connection with the
same e.g. filling materials, e.g. based on polyurethane
or like etc. Furthermore for the part of the overflow
arrangement, it is possible to carry out the downwardly
sloping guide surface by straight surfaces, getting
deeper periodically, or e.g. by a continuously arched
surface, which may be either convex or concave. In
connection with the counterpart surface it is
furthermore possible to use certain kinds of flow
guidance arrangements, such as e.g. a perforated or
grooved guide plate, by means of which the surface scum
is being steered tangentially on the surface of the
primary space. The surface scum may be removed from the
secondary space also by means of e.g. a pump or by a
separate scavenging or whatever way, in case it is
required due to the quality or amount of the surface
scum.
WE CLAIM ;
1. A method for removal of surface scum with a system comprising an
overflow arrangement comprising a first surface chute arrangement
arranged in a substantially crosswise direction with respect to a
longitudinal direction of the liquid basin, the first surface chute comprising
a primary space and a secondary space configured to let the surface scum
overflow in at least two successive phases from the liquid basin into the
primary space and from the primary space into the secondary space, an
exhaust assembly operatively connected to the overflow arrangement to
exhaust the surface scum, and a second surface chute, the method
comprising:
controlling overflow of the surface scum from the primary space to the
secondary space to minimize an amount of water drifting together with
the surface scum by adjusting a level of the liquid in the primary space
with at least one of a flow balancing assembly connecting the primary
space and the second surface chute arrangement, or an adjusting device
arranged in a wall defining the primary space and the secondary space.
2. The method as claimed in claim 1, comprising: controlling the overflow of
the surface scum from the primary space to the secondary space by
adjusting a discharge height of one or more flow pipes or channels of the
flow balancing assembly, with adjusting means arranged at the end of
said exhaust assembly.
3. A system for removal of surface scum from a liquid basin, the system
comprising:
an overflow arrangement (2al) comprising a first surface chute (2a)
arranged in a substantially crosswise direction with respect to a
longitudinal direction (3) of the liquid basin (N), the first surface chute
(2a) comprising a primary space (I) and a secondary space (II) configured
to let the surface scum overflow in at least two successive phases from
the liquid basin (N) into the primary space (I) and from the primary space
(I) into the secondary space (II);
an exhaust assembly (P) operatively connected to the overflow
arrangement (2al) to exhaust the surface scum;
a second surface chute (2c) configured to control overflow of the surface
scum from the primary space (I) to the secondary space (II) to minimize
an amount of water drifting together with the surface scum by adjusting a
level (h1) of the liquid in the primary space (I); and
at least one of a flow balancing assembly (2a2) connecting the primary
space (I) and the second surface chute (2c) or an adjusting means
(2a,2b) configured to control flow between the primary space (I) and the
secondary space (II).
4. The system as claimed in claim 3, wherein the flow balancing assembly
(2a2) comprising at least one flow pipe (2a2a) and channel at least one
(2a2a), the system further comprising:
adjusting means (2a2b) arranged at an end of the at least one flow pipe
(2a2a) or channel (2a2a) of the flow balancing assembly (2a2), wherein
the adjusting means (2a2b) comprises an adjustment sleeve and is
operative to adjust a discharge height (hv) of the flow balancing assembly
(2a2).
5. The system as claimed in claim 3, wherein the secondary space (II) is
arranged, when viewed in the longitudinal direction of the liquid basin (N),
transversely after the primary space (I), such that the secondary space
(II) descends towards the exhaust assembly (P), when viewed in a
crosswise direction of the liquid basin (N).
6. The system as claimed in claim 3, wherein the secondary space (II) is
arranged at least one end of the primary space (I), when viewed in a
crosswise direction of the liquid basin (N).
7. The system as claimed in claim 3, wherein the overflow arrangement (2a1)
is arranged to settle freely in a direction of height (h1) along with the
surface (V)of the liquid basin (N) by using floating structures (KR).


The invention relates to a method for removal of surface scum by means of
an exhaust device (2) that exists in connection with a liquid basin
(N), such as a settling tank, the exhaust arrangement comprising a first
surface chute (2a), existing essentially in a crosswise direction with respect to
a longitudinal direction (s) of the liquid basin, for removal of surface scum by
means of an overflow means (2al), belonging to the liquid basin and being
based on a continuous flow, by means of which the surface scum is being
overflown in at least two successive phases, in the first phase from the fluid
basin into a primary space (I) existing in the fluid basin, and in a second
phase into a secondary space (II) from the primary space (I) situated further
ahead in the fluid basin, from where it is being finally exhausted from the
liquid basin by means of an exhaust assembly (P) for the surface scum, such
as by one or more exhaust pipes, or channels, and a second surface chute
(2c) for removal of liquid, being processed in the liquid basin, such as
clarified water. Overflow of the surface scum existing in the primary space
(I), to the secondary space (II) is being controlled particularly in order to
minimize the amount of water drifting together therewith by adjusting the
level (h1) of the liquid in the primary space (I) by means of a flow balancing
assembly (2a2), connecting the primary space (I) and the second surface
chute (2c), and/or by using an adjusting device (LL) existing in the wall
defining the primary space (I) and the secondary space (II), and in that the
scum on the surface of the liquid basin (N) is overflown to the primary space
(I) by means of a downwardly slopping guide surface (V) to maintain a
laminar flow of the surface scum.

Documents:

03551-kolnp-2006-abstract.pdf

03551-kolnp-2006-claims.pdf

03551-kolnp-2006-correspondence others-1.1.pdf

03551-kolnp-2006-correspondence others.pdf

03551-kolnp-2006-correspondence-1.2.pdf

03551-kolnp-2006-description (complete).pdf

03551-kolnp-2006-drawings.pdf

03551-kolnp-2006-form-26.pdf

03551-kolnp-2006-form1.pdf

03551-kolnp-2006-form2.pdf

03551-kolnp-2006-form3.pdf

03551-kolnp-2006-form5.pdf

03551-kolnp-2006-international publication.pdf

03551-kolnp-2006-international search authority report.pdf

03551-kolnp-2006-other document.pdf

03551-kolnp-2006-pct request.pdf

3298-KOLNP-2006-FORM-27.pdf

3551-KOLNP-2006-ABSTRACT 1.3.pdf

3551-KOLNP-2006-ABSTRACT-1.1.pdf

3551-KOLNP-2006-ABSTRACT-1.2.pdf

3551-KOLNP-2006-ABSTRACT.pdf

3551-KOLNP-2006-AMANDED CLAIMS-1.1.pdf

3551-KOLNP-2006-AMANDED CLAIMS-1.2.pdf

3551-KOLNP-2006-AMANDED CLAIMS.pdf

3551-KOLNP-2006-CORRESPONDENCE 1.1.pdf

3551-KOLNP-2006-CORRESPONDENCE 1.4.pdf

3551-KOLNP-2006-CORRESPONDENCE 1.5.pdf

3551-KOLNP-2006-CORRESPONDENCE-1.2.pdf

3551-KOLNP-2006-CORRESPONDENCE-1.3.pdf

3551-KOLNP-2006-CORRESPONDENCE.pdf

3551-KOLNP-2006-DESCRIPTION (COMPLETE)-1.1.pdf

3551-KOLNP-2006-DESCRIPTION (COMPLETE)-1.2.pdf

3551-KOLNP-2006-DESCRIPTION (COMPLETE).pdf

3551-KOLNP-2006-DRAWINGS-1.1.pdf

3551-KOLNP-2006-DRAWINGS.pdf

3551-KOLNP-2006-ENGLISH TRANSLATION.pdf

3551-KOLNP-2006-EXAMINATION REPORT.pdf

3551-KOLNP-2006-FORM 1-1.1.pdf

3551-KOLNP-2006-FORM 1-1.2.pdf

3551-KOLNP-2006-FORM 1.pdf

3551-KOLNP-2006-FORM 18 .1.pdf

3551-kolnp-2006-form 18.pdf

3551-KOLNP-2006-FORM 2-1.1.pdf

3551-KOLNP-2006-FORM 2-1.2.pdf

3551-KOLNP-2006-FORM 2.pdf

3551-KOLNP-2006-FORM 26.pdf

3551-KOLNP-2006-FORM 3 1.1.pdf

3551-KOLNP-2006-FORM 3-1.1.pdf

3551-KOLNP-2006-FORM 3-1.2.pdf

3551-KOLNP-2006-FORM 3.pdf

3551-KOLNP-2006-FORM 5.pdf

3551-KOLNP-2006-FORM-27.pdf

3551-KOLNP-2006-GRANTED-ABSTRACT.pdf

3551-KOLNP-2006-GRANTED-CLAIMS.pdf

3551-KOLNP-2006-GRANTED-DESCRIPTION (COMPLETE).pdf

3551-KOLNP-2006-GRANTED-DRAWINGS.pdf

3551-KOLNP-2006-GRANTED-FORM 1.pdf

3551-KOLNP-2006-GRANTED-FORM 2.pdf

3551-KOLNP-2006-GRANTED-SPECIFICATION.pdf

3551-KOLNP-2006-OTHERS 1.1.pdf

3551-KOLNP-2006-OTHERS-1.1.pdf

3551-KOLNP-2006-OTHERS-1.2.pdf

3551-KOLNP-2006-OTHERS.pdf

3551-KOLNP-2006-PETITION UNDER RULE 137-1.1.pdf

3551-KOLNP-2006-PETITION UNDER RULE 137.pdf

3551-KOLNP-2006-REPLY TO EXAMINATION REPORT 1.1.pdf

3551-KOLNP-2006-REPLY TO EXAMINATION REPORT.pdf

abstract-03551-kolnp-2006.jpg


Patent Number 250158
Indian Patent Application Number 3551/KOLNP/2006
PG Journal Number 50/2011
Publication Date 16-Dec-2011
Grant Date 13-Dec-2011
Date of Filing 28-Nov-2006
Name of Patentee FINNKETJU INVEST OY
Applicant Address REKITIE 1, FI-26510 RAUMA, FINLAND
Inventors:
# Inventor's Name Inventor's Address
1 TUOMIKOSKI, PEKKA VALTAKATU 4 A 11, FI-26100 RAUMA, FINLAND
PCT International Classification Number B01D 21/24
PCT International Application Number PCT/FI2005/000126
PCT International Filing date 2005-02-28
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 20040893 2004-06-29 Finland