|Title of Invention||
"AN APPARATUS FOR REMOVING WATER SOLUBLE POLLUTANTS LIKE OXIDES OF CARBON, NITROGEN AND SULPHUR AND SUSPENDED PARTICULATE MATTER OF SIZE DOWN TO A RANGE OF 100M-150MFROM EFFLUENT GASES.
|Abstract||Devices for removal of solid and gaseous pollutants have been in use but almost all of them were costly and energy intensive, often requiring considerable space The present invention relates to an apparatus for removing pollutants from effluent gases, which comprises in combination- (a) a tank (1) having at least one inlet and one outlet piping systems and filled with water upto a predetermined level (2); (b) a short piece with flange (5) in one of the side walls of ihe tank connected to the suction side of an I.D. fan; (c) gas settling-cum-distribution unit and main bubbler ring comprising- (i) a vertical down comer pipe (7) leading from the inlet connection flange (4) down almost to the bottom of tank; (ii) a settler (6) open at the bottom to which the down comer pipe is connected ; (iii)a plurality of connecting arms (ii) branching out in the horizontal plane from the said settler (6) and (iv)ring main (8) for allowing the gas to bubbler out through the holes (13) drilled therein|
|Full Text||The present invention relates to an apparatus for removing water soluble/ and suspended particulate matter/from effluent gases. More particularly, this invention pertains to a system which is an efficient pollution control device thai effectively removes both suspended particulate matter and also soluble noxious compounds present in gases emanating from furnaces, incinerators, burners and the like devices causing atmospheric and ground pollution.
Atmospheric pollution by hot gases emanating from burner, furnace, oven, etc. causes many problems has always been a bane for the civil authorities. Such gases are invariably laden with minute solid particles, often less than 10 µm size which not only pollute the atmosphere, but also cause severe damage to the flora and fauna around the source of emission. The hot gases tend to raise the atmospheric temperature and contribute to global warming and invariably carry gaseous pollutants which are potential health hazard and may even result in acid rain destroying crops and fertility of soil. The adverse effects on floriculture in and around Kolaghat thermal power station in West Bengal is a glaring example of what damage the particulate impurities present in effluent gases can inflict
To tackle this scourge of industry, such as foundries in India particularly in and around Kolkata, various types of control devices have hitherto been put to use for arresting suspended solid particles. Some such devices are, inter alia, (i) dry cyclone separator, (ii) Wet venturi scrubber, (iii) bag filter, (iv) electrostatic precipitator, etc. Most of these devices are expensive, occupy fairly large space and consume considerable amount of energy for their operation to capacity, which again adds to the operational cost apart from considerable expenditure on their installation, commissioning and maintenance.
Moreover, it has been found that furnaces, burners, incinerators, etc. installed and operated by small and medium scale units cause considerable pollution because of financial constraint on one hand and lack of awareness on the other. Authorities have often taken a lackadaisical attitude towards the issues of pollution and most of the time the erring entrepreneurs have been given a wide berth.
In recent times, State Pollution Control Boards and the Judiciary have taken cognizance of the pollution hazard and public awareness has also played an important
role in tackling the problem of pollution and formulating legislation and setting norms to determine the critical limits.
The principal object of this invention is to provide an apparatus capable of removing Water soluble pollutants from gases emanating from burners, furnaces, cupolas, ovens, incinerators, crematoria and the like systems.
A further object of this invention is to provide an apparatus or a system for effectively controlling atmospheric and ground pollution by arresting small size (often 10 µm) particulate matters and also by substantially eliminating noxious compounds present in this effluent gases.
A still further object of this invention is to devise a virtually maintenance free system for handling hot gases laden with suspended solid particles and hazardous gaseous pollutants.
Another object of this invention is to provide an apparatus which not only arrests particulate and gaseous impurities but also brings down the temperature of the effluent gases hereby preventing greenhouse effect.
Yet another object of this invention is to design, fabricate and instal an apparatus which is not only cost- effective but also uses indigenous material and technology.
A still another object of this invention is to provide an apparatus or.a system for combating atmospheric and ground pollution which can be installed as an ancillar)' unit to an existing conventional pollution control device such as cyclones, bag filters, electrostatic precipitators etc.
The foregoing objects are achieved by the present invention according to which
there is provided an apparatus for removing water soluble pollutanis/and suspended
particulate matter/from effluent gases which comprise, in combination,
(a) a tank having at least one inlet and one outlet piping systems and filled with water upto a predetermined level,
(a) a short piece with flange at one of the side walls of the tank connected to the suction
side of an I. D. fan,
(b) gas settling -cum- distribution unit and main bubbler ring unit comprising
(i) a vertical downcomer pipe leading from the inlet connection flange down almost to the bottom of the tank,
(ii) a settler open at the bottom to which the said down-comer pipe is connected, (iii) a plurality of connecting arms branching out in the horizontal plane from the
said settler and (iv) ring main for allowing the gas to bubble out through the holes drilled (herein,
The connecting arms are attached to the ring main distributor, usually circular in
The gas settling - cum - distribution unit of the subject apparatus is a cast/fabricated
structure for conveying, distributing and bubbling out the inlet gas through water in
the tank. The settler, the arms, the ring main and a part of the downcomer are
submerged in water in the tank.
Usually there are provided four numbers of connecting arms, uniformly spaced. The
water tank may be equipped with a liquid level indicator, either a transducer type or
a glass gauge liquid level indicator. A flange connection may be provided at the top
for filling in water together with man-hole cover. A drain valve may be provided at
the bottom for, The drain valve may be connected to the drain line (9) provided for
the purpose to drain out the tank, as and when necessary. The space on the top cover
of tank may be effectively utilised for installation of equipment like fan, motor, etc.,
by adopting suitable means therefor.
Hot /cold effluent gases laden with particulate and gaseous pollutants come out of
the process equipment such as mentioned above. The gas enters the system through
the inlet pipe either directly, or after coming out of a primary control device, to a dry
cyclone separator. An induced draft fan (abbreviated as 1. D. fan) draws the gas
through the device where the gas bubbles through water contained in the tank
Fine suspended particles and soluble noxious pollutants get trapped / arrested /
dissolved in the water and relatively clean gas is released into atmosphere through a
stack at an appropriate height.
The invention essentially resides in bubbling out dust laden gas through water which
results in trapping suspended fine particles present in the gas. The present apparatus
effectively causes particulate impurities to settle at the bottom of the tank, and
utilises fluid drag, surface tension effect and normal gravitational pull, overcoming
the forces due to pressure gradient and buoyancy, for holding back the fine particles. All these make the process of dust separation by the apparatus very efficient. The apparatus/device of this invention has a central dust settler at the end of a down-comer which decelerates this flow and increases the residence time, thus facilitating dust separation. The distributor ring main has a number of holes in it through which the gas comes out, ensuring reasonably uniform distribution of dust particles and absorption of substantial amounts of noxious gases in water. As mentioned earlier, the gas space in the tank is connected to the suction side of the fan, which means that the I.D. fan receives a cooler gas with less volume to handle.
The invention will be more particularly described by the accompanying drawings in which-
Fig. 1 is the front sectional view of the subject apparatus along section AA. Fig 2 is the top view of the system, indicating therein section AA and J'ig 3 is the enlarged view of the portion marked by "X" in Fig.l. In Fig. 1 there is shown a tank of concrete/brick structure /fabricated structure (1) which houses other components of the system as well as water needed for its operation, the tentative level of which is shown by (2). The top of the tank (3) has a flange connection (4) on it for facilitating ingress of the dust laden gas in the tank (1). At one of the side-walls near the top, there is a flange (5), called "Exhaust Flange" which is connected to the suction side of the I.D. fan, drawing relatively clean air out of tank, and serving as the gas outlet.
The apparatus has a gas settling -cum-distributor unit and a ring main bubbler unit, which are M.S./ C.I./ S.S. structures for conveying, distributing and bubbling out of the inlet gas through the water contained in the tank (1) and consists essentially of a vertical down comer pipe (7) leading from the inlet connection flange (4) to the settling unit (6), extension of the settling unit (14), four Nos. of distribution arms (11) and a circular ring main (8)
In Fig. 2 there is shown a top view of the apparatus in which (6) is the settling unit serving as the gas settler-cum-distributor where the velocity of the particle laden hot gas is reduced. The downcomer (7) is suitably connected to the settling unit (6) Settling unit is fitted with an extension piece (14), which is open at the bottom, as shown in the enlarged view 'X' in Fig.3 of the drawings. A number of distribution
arms (11) branch out in the horizontal plane from the settling unit (6). These arm pipes carry holes (10) on them and, like the arms of a pulley, are connected to a circular ring main (8). The ring main serves the purpose of bubbling out the gas through two rows of holes drilled in it on angular stagger with specified triangular pitch (13). At the bottom region of the water tank, a flange is provided (9) for the drain pipe.
Fig.3, is the enlarged view of the bottom portion of the settling chamber (6). This bottom portion is called the extension pipe (14).
It will also be noticed from Fig.l of the drawings that the settling chamber (6), the arms (11), the ring main (8), the extension piece (14) and a portion of the down comer (7) are all submerged in water.
For determining the level of water inside the tank, there may be installed a liquid level indicator, either of a glass gauge or a transducer type. The pressure in the space above water inside the tank being less than atmospheric, the glass gauge must be connected to the space above the liquid level in the tank for true recording of water level inside. One flange connection (12) for filling water into the tank. A man-hole cover may be provided at the top, which have, however, not been shown in the drawings. Moreover, the space on the top cover of the tank may further be put to use by making provision for installation of fan and motor on the said top cover itself by suitable means.
The Present invention will be further amplified by the following Example given by way of illustration and not by way of limitation.
Raw materials were procured according to following specifications to cupola melting and production of cast iron articles of different shapes, size and configurations :
RAW MATERIAL SPECIFICATIONS
FOR CUPOLA MELTING
I. PIG IRON
IS : 224/79 1 Foundry Pig Iron.
( 1.0/1.5) High Mn or Low Mn. 0.5/1.0
Grade B/C Grade-1 to Grade IV Si : varying 2.75/3.25, 2.25/2.75,
1.75/2.25, 1.25/1.75 S : 0.25 Max. P : 0.40 Max
Only clean metallic scraps to be used. No rust or moisture of fine particles (like Churans, Borings, Turnings ) to be used.
Metallurgical Grade/Foundry Grade.
Low Ash. ( 10 - 12 % of the metallic charge )
Fixed carbon 86.0%
Ash Max. 12.0%
V. M Max. 2.0%
Moisture Max. 3.0 %
Sulphur Max. 0.8%
Size Above 1/10 th of
3. LIME STONE
Such production of ferrous materials was carried out in different units using the apparatus of the present invention and the resultant effect of SPM (mg/Nm3) level before and after installation are shown below in a tabular form.
After Installation Before Installation
SI. No. Name of the Unit Tcmperatur c'C VeIocityofGas m/scc Qty.of Gas
m3hr. Ash %
mg/Nm3 SPM mg/Nm3
1. K. P. Das & Sons (P) Ltd. 37.0 7.68 5054.10 20 121.07 936.28
2. S. C. Ghosal & Sons 40.0 7.71 3215.30 24 132.48 1032.43
3. P.R. Industries 41.0 7.71 5183.30 28 127.88 886.92
4. Chandimata Iron Industries 70.0 7.65 4598.55 28 98.40 1316.12
Do 44.0 7.5 83.43 450.00
5. The coronation Engineering Works 35.2 7.59 6423.88 28 139.72 1582.02
6. Ma Kali Iron Works 30.5 6.19 4241.72 28 130.24 849.00
7. Urvashi Steel 46.0 8.24 5357.89 28 105.99 1396.67
Industries (P) Ltd.
8, Sourabh Casting 30.0 4.68 2997.17 28 131.40 1548.45
9. A. K. Jspat Udyog 44.0 6.35 4092.28 28 124,43 1570.77
10. Shri Kali Iron Foundry 67.0 4.65 708.83 28 102.64 571.37
11. U. L. Iron Foundry 39.0 7.73 5061.03 14 103.42 1804,55
12, Dashurathi Foundry Works (P) Limited 42.0 6.73 4563.87 28 101.18 450.00
13, Raghunath Iron Foundry 45.0 4.50 2326.00 30 117.00 1453,00
14. Shri Chandi Iron
Foundiy 46.0 6.65 11459.95 20 142.00 1163.90
15. Bharat Engg. Corporation 35.0 4.20 2755.00 30 129.00 2516.00
16, S..R. Casting Corporation 50.0 6.50 3857.00 30 124.00 1950.00
17. Bengal Foundry Co. 40.0 11.10 7266.00 30 84.00 709.00
18, Welington Hardware 49.0 7.75 4114.70 28 118,49 450,00
19. Hazra & Sons 32.0 7.87 5372.75 28 138.25 1785.00
20. Lakshmi Foundry Works P. Ltd. 40.0 6.72 5109.17 28 91.82 3379.34
Do 42.0 8.26 6241.38 28 77.20 450.00
Do 50.0 5.8 4051 30 134.96 450.00
21, Great Sastar. Foundry 47.0 5.8 3002 89.00 450.00
22. K. M. Iron Foundry 92 8.6 3133 137.00 1285.00
39 4.42 738 69.00 450.00
23. R, M. Industry 38.0 6.67 4612.70 28 118.34 735.52
24. Hazra & Brothers 47.0 6.58 4241.71 28 117.09 450.00
25. Town Engg. Works 41.0 4.74 3220.68 28 89.91 1070.89
49.0 6.94 4598.36 28 140.44 450.00
1. A major achievement of this invention is the successful arrest of fine suspended particles emanating with the flue gases coming out of C.I. foundries in Howrah. West Bengal. As may be seen from the comparative studies given in the data above. by using this device the SPM level was brought down to much below 150 mg/Nm3, the stipulated norm set by W.B.P.C.B.
2. The system/apparatus being one of the wet type, the temperature of the gas the fan has to handle is much low which results in a lower capacity requirement and an increased life of the fan.
3. The subject apparatus is capable of removing both particulate and gaseous pollutants from the effluent gases, simultaneously bringing down the temperature of the outgoing gas stripped of its pollutants.
4. The design and construction /fabrication of the apparatus of this invention is simple and maintenance cost is minimal, particularly when compared to conventional pollution devices.
5. The apparatus is very much cost effective, being around ten times less costly than a functionally competitive equipment.
Additional modifications and improvements of the present invention would be apparent to those skilled in the art. Thus, the particular combination of parts denoted and illustrated herein is intended to represent only one embodiment of the present invention and is not intended to serve as limitations of alternative devices within the spirit and scope of the invention.
Having described in invention in detail with particular reference to the examples given above and also the accompanying drawings, it will now be more specifically defined by means of claims appended hereafter.
1. An apparatus for removing water soluble pollutants/and suspended particulate
matter from effluent gases, which comprises in combination-
a) a tank (1) having at least one inlet and one outlet piping systems and flllcd with
water upto a predetermined level (2) ;
A b) a short piece with flange (5) in one of the side walls of the tank connected to the
suction side of an I.D. fan;
c) gas settling-cum-distribution unit and main bubbler ring comprising-
(i) a vertical down comer pipe (7) leading from the inlet connection flange (4) down
almost to the bottom of the tank;
(ii) a settler (6) open at the bottom to which the said down comer pipe is connected;
(iii) a plurality of connecting arms (11) with roles (10) branching out in the horizontal
plane from the said settler (6) and
(iv) ring main (8) for allowing the gas to bubbler out through the holes (13) drilled
therein the capacity of the said apparatus to handle pollutant ladengas varying between 6000M3/hr and
2. An apparatus as claimed in Ciaiml, wherein the ring main distributor is usually
circular in shape (8), to which are attached connecting arms.
3. An apparatus as claimed in Claims land2, wherein there is provided four
connecting arms spaced uniformly apart.
4. An apparatus as claimed in Claims I to 3, wherein the gas settling-cum-
distribution unit is a cast or fabricated structure with an extension piece (14) for
conveying, distributing and bubbling out the inlet gas through water in the tank.
5. An apparatus as claimed in Claim 1, wherein the settler (6), the arms (11), the ring
main (8), the extension piece (14) and a part of the down comer pipe (7) are
submerged in water in the said tank.
6. An apparatus as claimed in Ciaiml, wherein the said water tank is equipped with
a liquid level indicator, either a transducer type or a glass gauge liquid indicator.
7. An apparatus as claimed in any of the preceding claims, wherein a flange
connection (12) is provided at the top (3) for filling in water, and a drain-line (9)
is provided at the bottom of the tank for completely draining out the tank, as and when necessary.
8. An apparatus as claimed in Claim 1, wherein the space on top cover of tank is utilised for installing equipment like fan, motor, etc.
9. An apparatus as claimed in Claims 1 to 8 wherein the pollutant-laden gas enters the system or apparatus through the inlet pipe wither directly, or after being led through a primary control device, such as a dry cyclone separator, and the incoming gas is drawn with the help of an induced draft (I.D. fan), allowing the gas bubble through water in the tank.
10. An apparatus as claimed in Claims land 9, wherein there is provided a central dust settler at the end of said down comer pipe which decelerates the gas flow and increases the residence time, thus facilitating separation of pollutants, both particulate and gaseous.
11. An apparatus as claimed in ClaimlO, wherein the gas space in the tank is connected to the suction side of the fan, thereby ensuring that the I.D. fan will receive a cooler gas with less volume to handle.
12. An apparatus for removing water soluble pollutants/and particulate matter
effluent gases, substantially as herein before described with particular reference to
the accompanying drawings.
Dated this 30 th day of August 2004
Devices for removal of solid and gaseous pollutants have been in use but almost all of them were costly and energy intensive, often requiring considerable space
The present invention relates to an apparatus for removing pollutants from effluent gases, which comprises in combination-
(a) a tank (1) having at least one inlet and one outlet piping systems and filled with water upto a predetermined level (2);
(b) a short piece with flange (5) in one of the side walls of ihe tank connected to the suction side of an I.D. fan;
(c) gas settling-cum-distribution unit and main bubbler ring comprising-
(i) a vertical down comer pipe (7) leading from the inlet connection flange (4) down
almost to the bottom of tank; (ii) a settler (6) open at the bottom to which the down comer pipe is connected ; (iii)a plurality of connecting arms (ii) branching out in the horizontal plane from the
said settler (6) and (iv)ring main (8) for allowing the gas to bubbler out through the holes (13) drilled
|Indian Patent Application Number||00522/KOL/2004|
|PG Journal Number||21/2007|
|Date of Filing||30-Aug-2004|
|Name of Patentee||JADAVPUR UNIVERSITY, INDUSTRY INSTITUTE PARTNERSHIP CELL|
|Applicant Address||P.O JADAVPUR UNIVERSITY, KOLKATA-700032,|
|PCT International Classification Number||C02F 1/58|
|PCT International Application Number||N/A|
|PCT International Filing date|