Note: Descriptions are shown in the official language in which they were submitted.
CA 02504594 2008-10-15
Application No.: 2,504,594 - 9- April 29, 2008
Scrubbing Ionized Rainstorm TunneI ( S.I.R.T.)
Background of the Invention
Coal is the most abundant and easily recovered fonn of energy source currently
extant for
ali of the world's countries irrespective of their level of technological
advancement and
so is employed for power generation wherever it is feasible. Coal powered
electricity
generation emits huge quantities of C02 into the atmosphere and so coal is one
of the
biggest contributors to greenhouse gas emissions and therefore global warming.
Coal
burning also emits acid rain components (NOx & SOx) and toxic heavy cnetals
(Hg & U).
Invention Susnmary
The present invention simplifies the process of recovering and/or sequestering
of all toxic
and greenhouse gas emissions far more inexpensively than all other prior
apparatus and
methods.
An additional benefit of the present method is the recovery of waste heat that
is usuaily
vented to the atinosphere, for district heating or local industrial processes
furthering
efficiency of the Rainstorm Tunnel at eliminating greenhouse gas emissions.
The present invention is its unique design allows for:
= dramatically reduced construction and operating costs
= ease of maintenance
= ease of scalability
= penultimate scrubbing control device efficiency
The invention may consist of either a single tunnel or have multiple tunnels
run in series
or parallel and each to any length depending on the voluine of the effluent
and the
configuration of the power plant/effluent generating process andlor its site.
The chief
CA 02504594 2008-10-15
Application No.: 2,504,594 - 10 - April 29, 2008
efficiency of the invention comes from the use of ionized water in a tunnel
with spray
nozzles, but any scrubbing agent extant can be used depending on the
constituent
contamination of the effluent gas and how close to `zero emission' it is
desired that any
specific installation of "The Rainstorm Tunnel" process needs to be.
The invention provides for emulation and compression of the Hydrologic Cycle
in its
operation. In nature the Hydrologic Cycle uses chiefly heat, gravity,
electrical discharges
(lightning) and precipitation to cleanse the air. The vortices created due to
wind forces of
a storm combined with the resident time of particulates within moisture-laden
environments add to the cleansing and purifying of pollutant air. The
Rainstorm Tunnel
compresses the effects of the larger natural environment into an overall
linear controlled
environment to carefully control all variables for maximum efficiency. The
device scrubs
the effluent with a pressurized rain/spray that absorbs the toxic constituents
and is
collected by gravity and pumped to a settling tank to precipitate the fly ash.
The liquor
effluent is then received in an electro-coagulation tank to collect the
reinaining dissolved
toxic metals and oxides of sulfur and nitrogen. The laminar flow effect in the
tunnel sees
some gas moving by spray force and by tunnel shape in helical motion along the
outer
edges of the tunnel, while gases in the center are seen as traveling at
different velocities
and targeted to be spray-blown into the ponding sections at the base of the
tunnel to be
further mixed with the outer streams. Additional vortices created are the
effects of the
central flow folding into the outer flows at approximately the inner most edge
of the
helical fencelrib version or varying the orientation of the spray nozzles
along the length
of the tunnel. The chaotic or non-chaotic result of gas volume factors ratio
to helical
wavelength and amplitude factors are calculated dependutg on the volume and
constituency of the effluent stream using present day understandings of vortex
design,
absorption factors due to gas pressure, distance and titne traveled within
control device,
inaterial surface texture and area, and variables relating to the introduced
agent
properties. It is the intention of the Rainstorm Tunnel that a degree of the
momentum of
the swirling action within a helical vortex is maintained to provide a
continuous and
CA 02504594 2008-10-15
Application No.: 2,504,594 - 11 - April 29, 2008
maximal surface absorption, velocity and residence time as in nature as
opposed to other
methods of screening, filtering, catalytic chemical reductions, combustion
modifications,
and precipitating that require significantly more process energy and often
require
complete retooling of existing power plants. The Rainstorm Tunnel can
eliminate or
reduce the size of dust collectors, the need for coal preparation prior to
burning, lime
input for S02 scrubbing, bag-houses, electrostatic precipitators, complex
multiple grid
piping systems, pure oxygen and low nitrogen combustors and the attendant
maintenance
problems. The Rainstorm Tunnel using spray nozzles to create optimal droplet
sizes and a
Nozzle Auto-Positioning & Retrieval System (NAPRS) for ease of maintenance may
accommodate varying coal fired plant layouts and effluent stream volumes and
constituents with ease and flexibility. Because of this flexibility and
simplicity, the
Rainstorm Tunnel may also be segmented and portable to a degree impossible
with other
systetns of screening and filtering and settling.
Brief Description of the Drawings
In drawings which illustrate by way of example only an exemplary embodiment of
the
invention, a plan view of a scrubbing rain tunnel in communication with an
existing
power plant.
Figure 1 is a plan view of a scrubbing rain tunnel in communication with an
existing
power plant.
Figure 2 is a side elevation of the scrubbing rain tunnel of Figure 1.
Figure 3 is a helically ribbed tunnel in an embodiment of the scrubbing rain
tunnel.
Figure 4a is a cross-sectional view of an interior nozzle.
Figure 4a 1 is a further cross-sectional view of the interior nozzle of Figure
4a.
Figure 4b is a cross-sectional view of a Nozzle Auto-Positioning and Retrieval
System.
CA 02504594 2008-10-15
Application No.: 2,504,594 - 12 - April 29, 2008
Figure 4b1 is a further detail of the Nozzle Auto-Positioning and Retrieval
System
Figure 5 a cross-sectional view of a wall of the scrubbing rain tunnel with
embedded
piping.
Figure 6 is an isometric view of a portion of the scntbbing rain tunnel.
Detailed description of the drawiny-s
In accordance with the present invention briefly described herein Figure 2
shows a
greatly simplified system for removing all toxic constituents of any gaseous
effluent
stream at any temperature with or without heat exchangers (6) via spray
nozzles (15),
using ionized water, steam or slurry spray introduced into a sloped or
horizontal tunnel
(1, 9) to create a vortex in the exhaust stream thereby increasing its dwell
time in the
spray. The helical interior shaped version (Figure 3) creates ideal conditions
to maximize
the spray contact time with the exhaust stream. The single, double or triple
helical
fence/rib (7) embodied in the present invention minimizes construction
complexity and
cost as the fence/rib integrally strengthens the Ra.instorm Tunnel's
structure. Figure 3
shown represents a single helix, high fence & high frequency configurarion. An
actual
tunnel variation may incorporate as little as one or a multiple of helical
grooves/fences
along the tunnel surface (9) made of stainless steel with welded on rebar or
other high
strength/ high temperature resistant concrete/plastic/composite material to
become
integral with a formed concrete/plastic/composite tunnel (9) and drains (8)
therein to act
as ponding and collection devices. A Rainstorsn Tunnel version having only
spray
nozzles (Figures 4a, 4a1, 4b, 4bl) will impart the beneficial vortex,
centrifugal and
ponding effects without the impediment of a fence by having the piping on the
outer
periphery of the walls of the tunnel (9) with some of the nozzle heads (15)
extensible into
the very centre of the tunnel (9) to penetrate the central vortex created in
the tunnel using
the Nozzle Auto-Positioning & Retrieval System (NAPRS).
CA 02504594 2008-10-15
Application No.: 2,504,594 - 13 - Apri129, 2008
Figures 4b & 4b1 illustrate a tunnel section asld enlargement of the NAPRS.
Illustrated in
Figure 4b1 is the detail of the installed aspect of the NAPRS hydraulic spray-
head
moving device. Ionized water enters through rnain pipes (16b) which connect to
the
distribution pipes (17) which are held to the exterior of the SIRT by clamps
(26) bolted to
brackets (19) welded to a plate (24) which is bolted to the SIRT wall (9). The
distribution
pipes (17) feed pressurized ionized water to the connected feeder pipes (18)
through the
telescoping hydraulically operated feeder pipe extension (22) that penetrates
the SIRT
wall (9) and its liner (25) moving through a sleeve (23) to position the spray
head (15).
The hydraulic fluid is fed by hoses (37). The moving feeder pipe extension
(22) and the
feeder pipe (18) are held wit.hin a typical hydraulic cylinder (21) connected
to the
brackets (19).
Helical fencing (Figure 3) for certain applications may be constructed from
identical
modules arranged along a given calculated path for each particular
application, and may
inove through various frequencies within the path length. The high pressure
spray nozzles
(I5) that are arrayed along the fence/rib (17) or embedded in the walls of the
tunnel (9)
can be angled to impart radial and axial momentum to the effluent gas, and may
be
positioned alternatively in any location along the tunnel wall (9) being fed
from supply
pipes (16, 16b) and distribution pipes (17) running longitudinally or spirally
inside,
outside or embedded in the tannel wall (9). This advantageously results in a
decrease in
the necessary size and power of the induced draft/exhaust fans as the gas will
mix and
flow naturally by the vortex created by the fence/rib (7) and the spray and
causing a
natural centrifuge effect. Illustrated is the advantageous embodiment of the
invention
wherein the axial cross sectional Figure 2 shows induced draft/exhaust fans
(2) moving
exhaust gas through a branch tunnel (5) from the base of the existing vent
stacks (3) into
a downward sloped tunnel (1, 9) in which heat exchangers (6) can be installed
to create
process steam for steam stripping of volatile gases and sulfurs and/or heat
removal for
district heating/industry plus the necessary preheat of the ion spray and
reheating of the
effluent gas discharged to the atmosphere if desired. The Rainstorm Tunnel can
also enter
CA 02504594 2008-10-15
Application No.: 2,504,594 - 14 - April 29, 2008
the ground to take advantage of ground source cooling. Subsequently the new
stack
dimensions are dramatically reduced and therefore have less impact on the
local esthetics.
The initial parts of the tunnel (9) can contain, in the case of a coal fired
generating
station, a series of helically shaped or standard heat exchanger pipes (6) to
preheat the
slurry or ionized water and/or create steam to be used in steam stripping
volatiles from
the effluent gas, the configuration of which will depend on the constituent
effluent gas.
From the initial stage the tunnel (9) proceeds to a to a chamber (14) in which
the initial
highly concentrated liquor is collected to be pumped to sedimentation tanks
(13) and then
to electro-coagulation processing (12 ) and/or ozonation or any other existing
prior art
process necessary to purify the liquor and its off-gas. The purified liquor
may be
redistributed to the main tunnel to begin the scrubbing process again (Figure
6). From the
chamber (14) the tunnel (9) proceeds upward and can contain one and as many as
three
helical fence/ribs (7) positioned spirally along the tunnel wall (9) and such
ribs have
advantageously spaced spray nozzles (15) along its interior edge to tnaxiinize
exposure to
and dwell time of the exhaust gas in the ionized water or slurry spray and/or
steam.
Alternatively the nozzles themselves (15) embedded in the tunnel wall (9) can
impart a
cyclonic effect by their aspect with some of the nozzle heads extensible into
the very
centre of the tunnel to penetrate the central vortex created in the tunnel.
Alternatively the
NAPRS (Figures 4b, 4b 1), which the nozzles (15) can be mounted on, can move
the
feeder pipes (18) telescoping them through the tunnel wall (9) to either
hydraulically or
manually move them for ease of maintenance and safety of the workers as the
workers
would never have to enter the tunnel nor the tunnel shutdown for maintenance
(Figure 6).
The resultant is a controlled linear cyclonic rainstorm. Parameters will
include a sound
wave analysis to avoid potential reverberation resulting in sound and if
deemed necessary
by reverse wave sound deadening equipment instalIed. The ribs (7) can also act
as heat
exchangers if so desired by embedding piping within them or eventuating them
as pipes
as illustrated in Figure 3. The feeder pipes (18) (Figure 4al and Figure 4b 1)
for the spray
nozzles (15) are modularized and sectioned off for ease of maintenance. The
helical
fence/rib (17) in the sloped or horizontal tunnel (9) creates multiple natural
collection
CA 02504594 2008-10-15
Application No.: 2,504,594 - 15 - Apri129, 2008
points/pools as temporary storage of the liquor in the tunnel which then can
be siphoned
to the main drains and drain pipes (8, 39, 39a) and once the concentration of
contaminants in the runoff liquor has reached the desired level then the
liquor can be
piped away for further processing. The resultant purified exhaust is released
to the
atmosphere via the vent stack (10).
Note:
In the helical rib design (Figure 3) each drain (8) will contain diminishing
concentrations
of contaminants andlor coinpletely different contaminants both in relation to
the
increasing distance along the tunnel from the source of the coal smoke and
what is being
sprayed into the tunnel at that particular point, as both can vary according
to the
constituents of the effluent, which would allow differing levels of further
processing as
the liquor at every drain (8) would not need every step of the purification
process (as at
each collection point the concentration and/or makeup of the runoff liquor
varies and this
can create diminishing returns for effort expended to cleanse the liquor). The
last few
drains (8) can simply have their thinly contaminated liquor returned to the
first few spray
nozzles via a collection drain such as 39 in Figure 3 allowing for much more
efficient
reuse of the cleansing spray as it does not have to be processed to complete
purity before
being reused. Only liquor that has the highest concentration of contaminant
needs to be
piped away for further processing by electro-coagulation, electro
flocculation, precipitate
settling, aeration or sequestration (12) depending on the constituent
toxicity.
In simplified versions of the tunnel for effluent streams that are not highly
contaminated
or for small volumes of effluent the helical ribs can be eliminated and the
supply pipe
itself (16 or, optionally, 16b) on Figures 4a and 4b can either be shaped in a
helical or
straight-line configuration. In applications where a very high pressure of
ionized rain or
scrubbing slurry mixture is needed as in a coal fired exhaust stream, the
feeder pipe (18)
can be mounted inside the tunnel walls (9) with only the spray heads (15)
exposed to the
effluent in a helical or straight-line fashion or attached to the inside of
the tunnel walls (9)
CA 02504594 2008-10-15
Application No.: 2,504,594 - 16 - April 29, 2008
(Figure 5), such design placement and materials used dependant on the toxicity
and
corrosiveness of the effluent. In the case of a coal fired power plant the fly
ash would be
settled out in a pond, tank or optionally at the bottom of the tunnel (13b)
shown in Figure
6 and the resultant liquor further processed via electro coagulation (12) to
remove the
Sulfates and Nitrates that are the base in smelters, incinerators and other
high eznission
processes. Nox reduction in the effluent can take place before, during or
after the
Rainstorm Tunnel. Should the process be taken to its final and penultimate
stage the
carbon dioxide in the exhaust gas from the coal fired power plant or any other
effluent
stream, could be sprayed with a calcium and enzyme mixture for fitrther
sequestration as
carbonate. The tunnel maintains a closed loop and processes the resultant
liquor until the
water is pure enough to be reused in the tunnel. Dwell time and mixing in the
tunnel and
therefore contact time to the spray is varied according to the toxicity,
temperature and
density of the effluent gas by increasing or decreasing one of the following
variables
including but not limited to:
a) The fence / rib height
b) The slope of the tunnel
c) The length of the tunnel
d) The diaineter of the tunnel
e) The coil tigbtness (frequency) of the rib along the tunnel wall
f) The density of the spray nozzles
g) The orientation of the spray nozzles
h) The pressure of the spray
i) The number of fences coiled about one another on the tunnel wall
CA 02504594 2008-10-15
Applicat.ion No.: 2,504,594 - 17 - Apri129, 2008
j) The constituents of the spray
k) The size of the spray droplets
1) Surface texture on fence/ribs and tunnel wall
m) Periodically reversing or changing the aspects of the fence/rib coil on the
tunnel wall
n) Eliminating the fence/rib
o) Helical arrangement of the spray nozzles/pipe
p) Straight-line arrangement of the spray nozzles/pipe
q) Materials and design of the spray nozzles/pipe
r) Positioning of the spray nozzles/pipe in the vortex
s) Embedding the pipe in the tunnel wall
t) Attaching the pipe to the tunnel wall
u) Materials and design of the tunnel
v) Sealing the tunnel and batching the effluent to increase dwell time
w) Any combination of the above
Thus, in accordance with a first embodiment, there is provided a rainstorm
style of
cleansing apparatus for purifying effluent streams of gases comprising a first
exhaust pipe
having an inlet for introducing effluent gases being purified and an outlet
for discharging
purified gases to the atmosphere or sequestration with spray nozzles and
piping to
introduce an effluent scrubbing spray; a first heat exchanger consisting of at
least two
separate systems of piping, the first for removing heat to reheat the purified
exhaust
CA 02504594 2008-10-15
Application No_: 2,504,594 - 18 - April 29, 2008
stream of carbon dioxide for dispersion to the atmosphere if sequestration is
not desired,
and the second for preheating the purifying spray before introduction into the
tunnel
through main supply, distribution and feeder pipes having nozzles at their
terminus, such
piping being designed to have either a spiral aspect or straight line
configuration within
the tunnel and/or embedded in fences/vortex generators depending on the
specific
application of the rainstorm tunnel; tanks and/or hoppers with valves and
metering
equipment to supply said purifying substances; connected to the tanks/hoppers
a plurality
of main supply pipes, either in series or parallel, that run through the
second set of heat
exchangers; connected to the main supply pipes, distribution pipes, either in
series or
parallel, connected in such a way to supply said purifying substances to the
feeder pipes;
feeder pipes, connected to the said distribution pipes, extending through the
tunnel wall
and adapted to telescope back and forth through the tunnel wall, automatically
positioned
and retrieved to provide access to the nozzle heads, either hydraulically
manually for ease
of tnaintenance and safety of the workers as the tunnel will never have to be
shut down
unless desired, nor the workers exposed to the exhaust stream or its resultant
residue in
the tunnel; a plurality of nozzles located at the terminal of said feeder
pipes to spray
purifying substances into the exhaust stream; pumps and valves located before,
after or
along the main supply pipes to move and pressurize the said purifying
substances for
delivery to the distribution pipes and feeder pipes; a first sump drain or
plurality of sump
drains located in the bottom of the tunnel to drain said purifying substances
now
contaminated with effluent from the tunnel; connected to the sump drains a
pipe or
plurality of pipes with metering equipment and valves and pumps for carrying
said
contaminated purifying substances away for further processing, such processing
to be
dependant on the constituent contaminants; and a plurality of vortex
generators and/or
fences andlor piping provided within the tunnel to create a vortex within the
exhaust
stream thereby increasing the dwell time and the path length of the effluent
increasing the
efficiency of the scrubbing spray.
CA 02504594 2008-10-15
Application 1Vo.: 2,504,594 - 19 - April 29, 2008
The selection of purifying substances and the location of the nozzles may be
selected
according to the temperature and composition of the effluent gas.
The foregoing cleansing apparatus inay be used to mitigate or reduce toxic or
greenhouse
gas released from a coal-fired electricity generator.
There is also provided a cleansing apparatus for purifying effluent streams of
gases
comprising a first exhaust pipe (the rainstorm tunnel) having an inlet for
introducing coal
smoke with a blowback damper valve to suppress blowback during the startup
phase of
the coal furnace; outlets for discharging purified carbon dioxide to the
atmosphere; and/or
an outlet to a chamber/tank for compression of purified carbon dioxide to
provide a raw
material for further industrial uses; and/or an outlet to at least one further
rainstorm
tunnel in series or parallel from the first tunnel with all of the same
attributes of the first
tunnel as described herein, for sequestration of the carbon dioxide by
spraying a mixture
of enzymes and calcium to create limestone for use as a raw material for
further industrial
uses; and/or any combination of said outlets as desired; and/or a closed ended
tunnel to
increase dwell time and to allow for either complete capture and compression
of the
carbon dioxide or sequestration of the carbon dioxide as limestone; a first
heat exchanger
consisting of at least two separate systems of piping the first for removing
heat to reheat
the purified exhaust stream of carbon dioxide for dispersion to the atmosphere
if
sequestration is not desired and the second for preheating the purifying spray
before
introduction into the tunnel through distribution and feeder pipes, wherein
the piping is
provided with either a spiral aspect or straight line configuration within the
tunnel and/or
embedded in fences/vortex generators; tanks and/or hoppers with valves and
metering
equipment to supply said purifying substances; connected to the tanks/hoppers,
main
supply pipes, either in series or parallel, that run through the second set of
heat
exchangers in or on later areas of the turmel ultimately connected to nozzles
to deliver the
preheated scrubbing spray into the coal smoke exhaust stream, distribution
pipes as a
continuation of the main supply pipes designed mounted either on the outer
periphery or
embedded in the walls of said first exhaust pipe/tunnel and/or on the fences
and/or on the
CA 02504594 2008-10-15
Application No.: 2,504,594 - 20 - Apri129, 2008
vortex generators and/or the design and location of the pipes themselves so as
to to
produce a vortex in the exhaust stream; a plurality of feeder pipes connected
to the said
distribution pipes extending througb the tunnel wall configured to telescope
back and
forth through the tunnel wall, either hydraulically or manually; a plurality
of nozzles
located on the terminus of said feeder pipes, to spray purifying substances
into the
exhaust stream, in the fu-st areas of the tunnel the spray will consist of
purified ionized
water to absorb the greatest amount of heavy metal containing fly ash, noxious
nitrates,
sulfates, hydrogen fluoride and other volatile organic compounds; in later
areas of the
tunnel series the substances sprayed could consist of slurries of calcium and
enzymes to
sequester the excess carbon dioxide as limestone, such variation and
combination of
sprays dependant on the volume, temperature and constituents of the effluent
gas and its
suspended particulates as they vary along the length of the tunnel and whether
total
sequestration of the resulting purified stream of carbon dioxide is desired,
said nozzles
having angles and aspects aimed to produce a both vortices in the coal smoke
and to wash
the walls/fences/vortex generators within the tunnel; magnetic or electric
water ionizing
apparatus, around or within the said main supply pipes to ionize the water
within them; a
first sump drain or plurality of sump drains located in the first areas of the
tunnel at the
bottom of the tunnel to drain said ionized water, now contaminated with fly
ash and
heavy metals from the coal smoke in the tunnel, to drain from differing parts
of the tunnel
the contaminated ionized water which will have varying densities and
constituents of
contamination the further away they are drained from the tunnel inlet and the
source of
the coal smoke; connected to the sump drains in the first areas of the tunnel,
a pipe or
plurality of pipes for carrying said contaminated ionized water away to
settling
tanks/ponds whose design is known to those with ordinary skill in the art, to
separate the
fly ash from the ionized water; connected to the settling tanks/ponds a pipe
or plurality of
pipes to carry away the contaminated ionized water for sedimentation and/or
electro-
coagulation and/or electro-flocculation and/or membrane filtering and/or sand
filtering
processing to remove the heavy metals, nitrates, sulfates or volatile organic
compounds,
such processing to be dependant on the constituent contaminants; a plurality
of vortex
CA 02504594 2008-10-15
Application No.: 2,504,594 - 21 - April 29, 2008
generators andlor fences and/or piping disposed within the tunnel to create a
vortex
within the exhaust stream thereby increasing the dwell time and the path
length of the
effluent increasing the efficiency of the scrubbing spray.
The cleansing apparatus, in particular the tunnels may be segmented and
erected on
railroad bogies or highway floats for ease of transport or mobility, such that
the
segmented tunnels may be economically relocated and reused.
The cleansing apparatus thus provides for a nwnber of advantages, including
the
reduction of sulphur content produced by coal-fired electricity generation
plants; a
reduction in the use of bag-houses for fly ash separation, fluidized bed
combustion of
coal to reduce sulphur release, and low nitrogen burners or pure oxygen
burners in the
combustion of coal to reduce NOx release.
It is understood that various other embodiments and modifications in the
practice of the
invention will be apparent to, and can be readily made by, those skilled in
the art without
departing from the scope and spirit of the invention described above.
Accordingly, it is
not intended that the scope of the claims appended hereto be limited to the
exact
description set forth above, but rather that the claims be construed as
encompassing all of
the features of patentable novelty which reside in the present invention,
including all the
features and embodiments which would be treated as equivalents thereof by
those skilled
in the art to which the invention pertains. The ionized water spray main
supply pipes may
be introduced along the tunnel length (16 & 16b) in any nutnber and have
branched
piping into the tunnel at various intervals to effect the desired result
contained herein.
