|Title of Invention||
THE PROCESS FOR PRODUCING / GENERATING GOOD QUALITY WATER, FROM SEA / BRACKISH WATER
|Abstract||A process for producing / generating good quality water, from sea / brackish water, comprising of the following steps: the wasted flue gas from a coal or fossil fuel fired boiler of a themlal power plant, containing water vapor and sensible heat, is first quenched directly with sea / brackish water to saturate the flue gas with more water vapor from sea / brackish water, and subsequently the remaining heat in the flue gas is further quenched by direct contact with good quality water to cool the flue gas leading to condensation of water vapors in the flue gas.|
HELP OF INVENTION:
This invention relates to economic production extraction of good qualit}' water in large quantit}^ Further this invention relates to the unique process of evaporation, saturation and condensation of water in waste flue gas generated by firing coal/Lignite/fuel oil/natural gas and using sea / brackish water,
Good quality' water conventionally is being produced with known processes of REVERSE OSMOSIS, MULTI STAGE FLASH EVAPORATION or the conventional EVAPORATION &: CONDENSATION method. All these abo\'e methods require huge quantity' of energy by way of electricit}^ or thermal power to evaporate water. The PSC process, which is proposed in this patent, conceptualizes a technically feasible and commercially \nable solution for generation of large quantity of good qualit}' water from sea/brackish water and waste flue gas. In thermal power plants using coal fired boilers, enormous quantity of flue gas (typically 800 Metric Tons per hour - for a 210 MW capadty power plant) is liberated / dissipated into the atmosphere. This flue gas contains water (typically around 12% of the total quantity of flue gas) and the flue gas is also hot, (around 140 *^ Centigrade - termed as waste heat).
OBJECT OF INVENTION:
> The primary object of invention is to invent a method by which good quality water in large quantity can be obtained.
> It is another object of invention to invent a system by which good quality water in large quantity can be obtained by using the waste heat in a flue gas in combination with sea/brackish water
> The object of this invention is to produce large quantit}'^ of good qualit}'^ water at very low production cost, by maintaining a low operating cost as well as ensuring low initial investment.
> Further objects of the invention - clear from the following description.
SUMMARY OF INVENTION:
The PSC process incorporates extraction of water from sea / brackish water as well as from coal / fuel oil/ gas fired boiler flue gas, effectively utilizing the thermal power of the flue gas which is otherwise being dissipated into the atmosphere. Further this process is environment cleaner therefore air around large thermal plants will be much cleaner.
BRIEF DESCRIPTION: (Refer Diagram: 1)
In thermal power plants using coal fired boilers, enormous quantity of flue gas (tj^pically 800 Metric Tons per hour - for a 210 \4W capacitj^ power plant) is lit>erated / dissipated into the atmosphere. This flue gas contains water (t3^pically around 12% of the total quantity' of flue gas) and the flue gas is also hot (around 140 ^Centigrade - termed as waste heat).
The process envisages mixing of Sea / brackish water with the flue gas, to evaporate water, during which process the thermal energ}^ of the flue gas is absort>ed. The flue gas temperature drops to around 60 The water vapors in the saturated flue gas are now condensed and separated from the flue gas in the cooling stage. The flue gas is passed through a cooling unit where the temperature of flue gas is reduced from around 60f> centigrade to near ambient temperature - around 30^ Centigrade. Typically this cooling unit will utilize cold good quality water as the 'coolanf to directly absorb the thermal heat tiiat will be released during condensation of water vapor. (CoCh)
Major portion of the warm good quality is indirectly cooled with cold seawater, in a heat exchanger before being recycled as coolant to the cooling unit (HE). Rest of the warm good quality water is released for distribution.
About 100 tons per hour of good quality water can be produced / generated for distribution and utilization as cleaning, washing, toiletry and bathing water. In order to make the water potable, a sand bed filter with alum dosing may be required.
The above figures are indicative and will vary from plant to plant depending upon quality, quantity and temperature of flue gas as well as availability of Sea / brackish water.
DETATT ED PROCESS PESCRIPTTON: (Refer Diagram; 1)
With the help of a Blower Bl, hot flue gas (140 ^ C) is made to pass through the equipment (F Sz S unit) Evaporation and Scrubbing unit, where Sea / brackish water is sprayed into the stream of flue gas. Hot flue gas enters the unit through inlet No.2 and seawater is sprayed through several nozzles
^er'en different unit operations sequentiallv/ simultaneously Sz continuously take place inside this equipment (E ^ S nuit).
• , A1 is thp mfxfnp^ znne where thoroueh mixing of sea / brackish water
i^nd hot flue (^as is ensured b\^ '^trateeic placement of nozzles and fine atomized spraying of the water into the flue gas.
• A3 is the evaporation zone where some quantit}^ of water from the sea/ brackish water evaporates using the heat that is being liberated by the flue (^as.
• A4 is the neutralization zone where most of the acidic media in the flue gas is neutralized by the alkaline media present in the sea / brackish water.
• A5 is the saturation zone where it is ensured that the flue gas is now full}^ saturated with w^ater at the requisite temperature.
• A6 is the scrubbing zone where the suspended particulate matters in the flue gas is entrapped in the sea / brackish w'ater making the flue gas relatively free of particulate matters.
• A7 is the separation zone w^here the moisture laden flue gas is separated from the sea / brackish water now^ containing suspended particulate matters.
Tho sea/brackish water containing suspended particulate matters leaves the equipment (E & S unit) - Evaporation and Scrubbing unit through outlet No.: 3. The moisture laden f!ue gas passes through outlet No.: 4, sucked throueh the induced draft blower Bl to enter cooling cokimn CoCh through inlet No.: 5.
Tt may please be noted that the blower B can also be a forced draft blower located before equipment (V Sz S unit) or tivo different/ separate blowers may be located before iin6 ?ffer fhp ^qnipnuent to create a balanced draft
The cooling chaml^r CoCh will utilize cold good quality water (around 30^0 from a heat exchant^er HF as the 'coolanf to directlv absorb the thermal boat that will be released during condensation of the water vapor. The moisture laden flue gas is thus directlv cooled from around 60*Xr to near ambient temperature around ^O^^C.
The cold good qualit}' water (around 30*^C) drawn from the heat exchanger HE enters the cooling column CoCh through inlet No,: 6a and the warm good qualitA' water along with the freshly condensed good qualify water will leave the cooling column CoCh through outlet No.: 6b & 6c, Most of the water vapor in the saturated flue gas is condensed as water in the cooling column CoCh.
The warm good qualit}^ water (around 60*^) thus generated will be cooled indirectly, with cold seawater as the coolant, in the heat exchanger HE and recycled - returned back to the cooling chamber CoCh The cold flue gas leaves the cooling chamber CoCh, through outlet No.: 7 and enters the stack St and released into the atmosphere outlet No,: 8. The warm seawater generated in the heat exchanger is cooled in a cooling tower Ct before being returned to the sea.
We expect to produce more than 100 Tons per hour of good quality water from the flue gas being liberated by a coal fired boiler of a 210 MW capacity thermal power plant Good quality water^ well enough for being used in washing, cleaning, bathing, toiletry and gardening purposes.
DETAILED SYSTEM DESCRIPTION: fRefer Diagram :2)
An insulated Mild steel dnct '2' will com'py the hot fhie gas of tho holler (around 140° C) in the thermal power station, to the system located nearh/. An isolation damper maj' he pro\'ided in the duct to separate the boiler in the thermal power station and the system.
BIOWER 'Bl': There will be sex'eral blowers in the complete PSK process, to convey the flue gas. The blowers will main!}' be of centrifugal t}'pe, operatin^r either as forced draft blowers, induced draft blowers or as balanced draft blowers.
FVAPORATION & SCRUBBING unit 'E & S' is the most critical equipment in the complete PSK process. Seven different unit operations take place inside this equipment sequentially, simultaneously and continuously. Several identical evaporation and scrubbing units of lesser capacity may be placed and located in parallel for ease of operation and maintenance.
At the top of the equipment where the flue gas enters, also called the mixing zone. Strategicalh^ placed nozzles will spray sea / brackish water into the hot flue gas entering the equipment The water in the sea / brackish water quench the heat of the flue gases in the quenching zone. While quenching the heat of the flue gas, water in the sea / brackish water evaporates, and mixes with the flue gas in the evaporation zone.
The transient piece of the neutralization zone will also be made of Mild steel with rubber h'ning inside. Reducing the volume of the equipment and ensuring that the temperature of the flue gas is constant will ensure complete saturation of the flue gas, in the saturation zone.
The pressure drop across the throat and cone section will determine the efficiency of the scrubbing zone to trap the particulate matters in the flue gas. The variable throat and cone section of the equipment will have to with stand erosion apart from corrosion and temperature.
Sudden release of pressure and a strategically placed mist eliminator will ensure separation of the sea / brackish water from the saturated flue gas in the separation zone. The saturated flue gas leaves the evaporation and scrubbing unit 'E & S' through a rubber lined mild steel duct and enters the cooling column CoCh,
COOLING COLUMN 'The CoCh^ is basically a chamber, with the warm saturated flue gas entering the chamber at one end, and the 'coolant^ cold good quality water being sprayed into the flue gas; for direct contact between saturated flue gas and water. For better efficiency and ease of operation and maintenance, several identical cooling columns may be installed in parallel and operated in parallel or series.
PLATE HEAT EXCHANGER 'HE ': The coolant cold good qualit}' water gets warm while passing through the cooling column (to around 60 ^ C). It is therefore cooled indirectly with seawater, by passing the warm water through plate heat exchangers, before being returned to the cooling column CoCh, A shell and tube heat exchanger can also be recommended with the seawater wetted parts made of Cupro - Nickle or equivalent material of construction.
COOLING TOWERS "Ct"r The warm seawater from the heat exchanger will l>e cooled in a cooling tower before being returned to the sea.
The complete PSK process will be operated using simple instrumentation and control systems. Temp>erature, pressure, flow and levels of water and flue gas will be suitably controlled, measured and recorded, wherever necessarj' continuously. The quantity and qualit}^ of good water generated will have to be analyzed, measured and recorded appropriately.
Characteristics of the Output Product:
The good quality generated by the envisaged process and system will be of much higher and better quality compared to seawater.
The Total Dissolved Solids (TDS) of the good quality water generated will be less than 500 parts per million (PP\4) as compared to the TDS of sea water which ranges between 35000 to 45000 PPM and brackish water TDS ranges 8000 and 12000 PPM.
Similarly the Total Suspended solids (TSS) will also be far less as compared to the total suspended solids in sea/brackish water.
The pH of the good quality water will be neutral (close 7.0)
The good quality water will l>e free from oil, grease, chlorine, iron, manganese etc.
Salient Features of the Process and System:
1. An invenHon termed 'PSC Process' which offers a high & efficient utilization of waste heat which otherwise is heing dissipated into the atmosphere, to generate large quantity of good quality water.
2. The PSC Process extracts the water already present in the gaseous media and also desalinates sea/hrackish water to generate good qualit}^ water in large quantity.
3. The seawater and for atmospheric air are used as heat sinks in the PSC Process.
4. The PSC Process efferti>'elv utilises inert gaseous media, which can better withstand temperature, corrosion and erosion for separation of Heater from the highh' corrosive sea/brackish water.
5. The PSC Process enables even large coal fired thermal power plants to let out cleaner and lesser flue gas into the atmosphere, thereby significantly reducing the pollution of air around thermal power plants. Therefore, the PSC Process is not just environmentally friendly, but also cleans up the environment.
6. The PSC Process traps the suspended particulate matters in the hot flue gas, contributing to pollution control. An important by-product of the PSC process is to make the thermal power plant more environments friendly and conform to the neo-stringent requirement of the pollution control law.
7. The PSC Process offers a significantly economic solution, with low production cost to produce good quality water in large quantity, by effectively extracting the water, which was otherwise being liberated into the atmosphere. The PSC Process enables low initial investment as well as low operating cost for the quality and quantity of good water produced per hour.
1) The process described, the fltie ens from a coal-fired boiler of a thermal
power plant consisting of good quantit}^ of water vapour is recovered by
quenching the flue gas first in seawater to saturate the flue gas and
subsequently in good water to condense the w^ater vapor in the flue gas.
2) The process described in claim ~ 1. some amount of water from seawater
3) The process described in claim 1 & 1, the temperature of the flue gas comes
dow^n to near saturation temnernture.
4) As per the claims K2, 8i ?, the flue gas is ftirther cooled by direct contact
with cold good w^ater.
5) As claimed in 4. the water ^'apour in the flue gas is condensed to produce
good qualit}/ water.
6) The process as claimed in 1,2,3,4. & 5 the flue gas saturation temperature is directly related to that of hot flue gas and quantum of water vapour in the flue 2as.
7) As described in claim 1, quenching of hot flue gas in seawater, scrubs the suspended particles and oxides of sulphur present in the flue gas, thus liberating cleaner flue gas into the atmosphere.
/. Claims arc worded dcfwc pivraliiy ofirtvcntion and cannot he considered underiinilv of invention.
- Claim (s) have been resubmitted duly reworded as desired.
2. 77?^ Process is a simple condensation process and the inventive step is
lacking. Hence not allowed imder section 2 (!) (j).
The process is not a simple straightforward condensation of water \'apor from flue gas. The flue gas of a then-nal power plant that is norma']}' dissipated into the atmosphere contains both sensible heat and latent heat. In the process, the sensible heat available in the hot flue gas is used to evaporate water from seawater and bring the unsaturated flue gas to saturation point (ftilly saturated with M^ater). Tt is ensured that the saturated flue gas is separated from seawater at / near the saturation temperature of the flue sias. Subsequenth\ the water vapor present in the flue gas is condensed.
3. Objection mimhers 16,17, and 19 of this office letter dated 05 ' 05 ^ 06 has
not been met.
4. Preamble to description should be corrected as indicated in provisional
5. Last date expires on 05 / 05 / 07. (12 months from FER) as per Patents
(Amendment) Rides 2006.
|Indian Patent Application Number||698/CHE/2004|
|PG Journal Number||02/2008|
|Date of Filing||19-Jul-2004|
|Name of Patentee||SHRI. S. KUMAR|
|Applicant Address||NO. 1 SECOND STREET, PADMANABHA NAGAR, ADYAR, CHENNAI 600 020.|
|PCT International Classification Number||B01D 1/22|
|PCT International Application Number||N/A|
|PCT International Filing date|