Title of Invention	"A PROCESS FOR PREPARATION OF A NON-TOXIC SYNERGISTIC COMPOSITION USEFUL FOR CLEANING/DESCALING OF APERTURES/PIPES"
Abstract	The invention provides a non - toxic synergistic composition comprising an edible acid and polyphosphate based clay suspending / cleaning agent and a process for preparation of said composition. The composition of present invention is particularly useful for cleaning of clogged hand pumps and tube wells by using developed non-toxic chemical - hydrofracturing process as well as for cleaning of clogged heat exchanger tubes and condenser tubes in power plants.

Title of Invention

"A PROCESS FOR PREPARATION OF A NON-TOXIC SYNERGISTIC COMPOSITION USEFUL FOR CLEANING/DESCALING OF APERTURES/PIPES"

Abstract

The invention provides a non - toxic synergistic composition comprising an edible acid and polyphosphate based clay suspending / cleaning agent and a process for preparation of said composition. The composition of present invention is particularly useful for cleaning of clogged hand pumps and tube wells by using developed non-toxic chemical - hydrofracturing process as well as for cleaning of clogged heat exchanger tubes and condenser tubes in power plants.

Full Text	This invention relates to a process composition useful for cleaning/descating of apertures/pipes. The invention also describes the process for cleaning/descaling of apertures /pipes apertures using the said composition. The composition of present invention is particularly useful for cleaning of clogged hand pumps and tube wells by using developed non-toxic chemical -hydrofracturing process as well as for cleaning of clogged heat exchanger tubes and condenser tubes in power plants etc. The cleaning of clogged hand pumps and tube wells assumes importance as their water yield decreases with time due to the clogging in and around aquifer channels, slits in the strainers of the wells and infiltration galleries by deposits of mineral crusts, biological matters, corrosion products like hydrated iron oxides, sand/silt etc. Conventionally, the clogged hand pumps and tube wells are cleaned by adopting either, (aO physical method or (b) chemical treatments of the wells. Reference may be made to following in this regard. (1. Frank e Clarke; " Corrosion and encrustation in water wells : a field guide for assessment, prediction and control"; Food and Agriculture Organization of the United Nations Rome 1980 (Publ). (2) Ajit Singh, "Development of Wells" Central Ground Water Board, Ministry of Agriculture & Irrigation. Published by Controller of Publications, Government of India, 1979). The physical methods conventionally used are (i) blasting in the vicinity of screen using explosive ropes, whereby the deposits in the vicinity of screen using explosive ropes, whereby the deposits in casing slots are removed, (ii) high pressure water jet washing so that water shoots out through well screen openings to effectively clean fine sand, silt and clay etc. from the water bearing formation and (iii) fracturing the clogged infiltration galleries by application of high pressure through high velocity water (hydrofracturing). These physical methods suffer from the following drawbacks. The blast Leg method, using explosive rope is effective only in removing depcsits from the casing slots but its effect on solid surface is relatively small and no significant effect is observed in the gravel beyond the casing. The high pressure water cleaning -methods, namely water jet washing and hydrof racturing make use of the kinetic energy of the pressurised water to force open the clogged apertures and hence are capable of opening only limited length apertures. However, these methods are of limited u~e if the clogging is due to the mineral cru st s. The chemical methods of cleaning of wells are based on treatment of wells at normal pressure with (i) detergents and tii) with sulfamic acid or muriatic acid for required duration followed by pumping out the well water. The disadvantage of detergent treatment is that t!r.ese compounds are difficult to degrade and their presence even at very low levels in the drinking water is harmful to human health. Further the detergents are incapable of cleaning the clogging materials of mineral nature. The disadvantage of the treatment of wells with muriatic or sulfamic acids is that these acids are highly corrosive to metallic parts and are also hamful to soil when they come out &:.ang with the wash water. Further, since no pressure io applied in the above chemical treatments involving detergent/acids, the depth of penetration of chemicals in the clogged apertures and infiltration galleries/water channels etc. is limited. The main objective of the present invention is to provide a non-toxic composition useful for cleaning/descaling of apertures/pipes which obviates the drawbacks of hitherto known such chemical compositions. Another objective of the present invention is to provide a novel process of chemical-hydrofracturing for cleaning the clogged hand pumps and tube wells using the said non-toxic composition, which obviates the drawbacks of hitherto known processes of cleaning the wells either by physical methods or by chemical treatment. Accordingly the present invention provides a process for preparation of a non-toxic synergistic composition useful for cleaning/descaling of apertures/pipes which comprises dissolving in water 1 to 25 wt% of edible acids selected from hydroxy and carboxylic organic acids such as tartaric, citric acid and 0.1 to 20 wt% polyphosphate based clay suspending/cleaning agent selected from di-sodium hydrogen phosphate, sodium hexametaphosphate and mixture thereof to make the final volume 100% to get desired non toxic synergistic composition. The edible acids used may be such as hydroxy and carboxylic organic acids such as tartaric acid, citric acid or mixture thereof. The poly phosphate based clay suspending/cleaning agent may be such as di-sodium hydrogen phosphate, sodium hexametaphosphate or mixture thereof. The water used may be river, lake, tap or well water. Accordingly the present invention also provides a process for the cleaning/descaling of apertures/pipes which comprises clogged hand pumps and tube wells with above said non - toxic composition at an applied pressure in the range of 0.1 to 1.0 bar for a period of 1 to 24 hours followed by hydrofracturing the well at a pressure in the range of 5- 800 bars followed by washing the well by injecting water. This chemical-hydrofracturing process utilises the synergistic effect of treating clogged wells with non-toxic composition at an applied pressure and the high pressure-water hydrofracturing processes to achieve enhanced penetration and cleaning. The non-toxic composition comprises of a mixture of one or more of the edible acids with clay and silt particle dispersing agent(s). This non-toxic composition is poured into the well after removing the metallic hand pump/tube well assembly and is allowed to react with the clogging materials for l to 24 hours duration under an applied pressure in the range of 0.1 to 1.0 bar. At the end of the reaction time, the well is hydrofractured by pumping-in water at a high pressure in the range 10 to SOO bars. After chemical-hydrof racturing, tie well is washed by purging with water. The clogging materials choking the apertures in the screens and slits of the pipe(s) are also cleaned using above formulation by brushing followed by washing with water. The cleaned metallic hand pump/tube well assembly is reinstalled in the cleaned well. The composition of the present invention is not merely a mixture but a synergistic mixture resulting in a composition having properties which are not merely an aggregation of the properties, but has synergistic properties which results in cleaning of clogged tube wells/hand pumps by using said non-toxic composition. The following examples are given by way of illustration of the present invention and should not be construed to limit the scope of the present invention. EXAMPLE - 1 The aquifer and the metallic assembly of the hand pump located at Ratibarh village on Bhadbhada - Sehore road in Bhopal District were cleaned by the process of this invention. The diameter of the well was 12.5 cm and the depth was 65 meters. The static water level before cleaning was 31.5 meters and the water yield of the well was 1.4 liters per minute. The non-toxic chemical cleaning solution was prepared by dissolving a mixture of 25 Kg tartaric acid and 4 Kg sodium hexametaphosphate in 150 liters of water. This solution was slowly poured in the well after removing the rods, cylinder and the pipes of the hand pump assembly. The inflatable rubber packer assembly was introduced in the well and inflated with air at a pressure of 300 bars to seal the well. After sealing the well, water was pumped into the well to create a positive pressure of 0.5 bar and left for a duration of four hours for reactions to take place between clogging materials and the cleaning solution. At the end of this reaction time, 1500 liters water was pumped in the well at high pressure in four minutes duration to hydrofracture the chemically treated aquifer apertures at a pressure of 40 bars. After abc-ve chemical -hydrof racturing, the well was back washed with water The metallic screen was cleaned by brushing with non-toxic chemsea. cleaning solution followed by thorough washing with water. The hand pump was reassembled by putting back the rods, cylinder and pipes in the cleaned well. The static level of the water in the cleaned well was measured to be 11.0 meters with a water yield of 12.5 liters per minute. EXAKFLE - 2 The aquifer and the metallic assembly of the hand pump located in the Sonkachha village of the Barasia tehsil under Bhopal District were cleaned by tfcui process of the invention. The diameter of the well was 12.5 cm and the depth was 95 meters. Before cleaning, the static water level was 6.4 meters and the water yield was 1.2 liters per minute. The non-toxic chemical cleaning solution was prepared by dissolving 15 Kg. of citric acid. 20 Kg of tartaric acid and 5 Kg of sodium hexametaphospha:e in 150 liters of water. This solution was slowly poured in the well after removing the rods, cylinder and the pipes of the hand pump assembly. The inflatable rubber packer assembly was introduced in the well and inflated with air at a pressure of 200 bar ;.o seal the well. After sealing the well, water was pumped into the well to create a positive pressure of 0.2 bar and left for a duration of four hours for reactions to take place between clogging materials and the cleaning solution. At the end of this reaction time, 1800 liters of water was pumped in the wc;ll at high pressure in six minutes duration to hydrofracture the chemically treated aquifer apertures at a pressure of 1C bars . After above chemical -hydrofracturing, the well was t-^ck washed with water. The screen and the slits in the metal pipe were cleaned using the non-toxic chemical cleaning solution by brushing followed by thorough washing with water. The hand pump was then reassembled by putting back the rods, cylinder and pipes in the cleaned well. The static level of the water in the cleaned well was measured to be 3.0 meters with a water yield of 11.0 liters per minute. The following are among the main advantages of the invention. 1. The process of cleaning the clogged hand pumps and tube wells described in the present invention makes use of synergistic effect of chemical reaction (of the cleaning formulation with clogging materials to dissolve some of its constituents and thus loosening the clogging material in the apertures) and applied pressure for hydrofracturing, in the presence of the non-toxic chemical composition solution to efficiently open the clogged aquifer apertures. 2. The chemical formulation ust.d in cleaning operation consists of one or more edible acids along with a clay and silt dispersing constituent, alL of which are of non-toxic nature. 3. The use of clay and si 11 dispersing constituent in the formulation reduces the tendency of fine sand and clay particles to settle in the bottom of the well during the back washing operation of the weLL. We Claim: 1. A process for preparation of a non-toxic synergistic composition useful for cleaning/descaling of apertures/pipes which comprises dissolving in water 1 to 25 wt% of edible acids selected from hydroxy and carboxylic organic acids such as tartaric, citric acid and 0.1 to 20 wt% polyphosphate based clay suspending/cleaning agent selected from di-sodium hydrogen phosphate, sodium hexametaphosphate and mixture thereof to make the final volume 100% to get desired non toxic synergistic composition. 2. A process for preparation of non-toxic synergistic composition useful for cleaning/descaling apertures/pipes substantially as herein described with reference to the examples.

Full Text

This invention relates to a process composition useful for cleaning/descating of apertures/pipes. The invention also describes the process for cleaning/descaling of apertures /pipes apertures using the said composition.
The composition of present invention is particularly useful for cleaning of clogged hand pumps and tube wells by using developed non-toxic chemical -hydrofracturing process as well as for cleaning of clogged heat exchanger tubes and condenser tubes in power plants etc.
The cleaning of clogged hand pumps and tube wells assumes importance as their water yield decreases with time due to the clogging in and around aquifer channels, slits in the strainers of the wells and infiltration galleries by deposits of mineral crusts, biological matters, corrosion products like hydrated iron oxides, sand/silt etc. Conventionally, the clogged hand pumps and tube wells are cleaned by adopting either, (aO physical method or (b) chemical treatments of the wells. Reference may be made to following in this regard. (1. Frank e Clarke; " Corrosion and encrustation in water wells : a field guide for assessment, prediction and control"; Food and Agriculture Organization of the United Nations Rome 1980 (Publ). (2) Ajit Singh, "Development of Wells" Central Ground Water Board, Ministry of Agriculture & Irrigation. Published by Controller of Publications, Government of India, 1979).
The physical methods conventionally used are (i) blasting in the vicinity of screen using explosive ropes, whereby the deposits in the vicinity of screen using explosive ropes, whereby the deposits in casing slots are removed, (ii) high pressure water
jet washing so that water shoots out through well screen openings to effectively clean fine sand, silt and clay etc. from the water bearing formation and (iii) fracturing the clogged infiltration galleries by application of high pressure through high velocity water (hydrofracturing). These physical methods suffer from the following drawbacks. The blast Leg method, using explosive rope is effective only in removing depcsits from the casing slots but its effect on solid surface is relatively small and no significant effect is observed in the gravel beyond the casing. The high pressure water cleaning -methods, namely water jet washing and hydrof racturing make use of the kinetic energy of the pressurised water to force open the clogged apertures and hence are capable of opening only limited length apertures. However, these methods are of limited u~e if the clogging is due to the mineral cru st s.
The chemical methods of cleaning of wells are based on treatment of wells at normal pressure with (i) detergents and tii) with sulfamic acid or muriatic acid for required duration followed by pumping out the well water. The disadvantage of detergent treatment is that t!r.ese compounds are difficult to degrade and their presence even at very low levels in the drinking water is harmful to human health. Further the detergents are incapable of cleaning the clogging materials of mineral nature. The disadvantage of the treatment of wells with muriatic or sulfamic acids is that these acids are highly corrosive to metallic parts and are also hamful to soil when they come out &:.ang with the wash water. Further, since no pressure io applied
in the above chemical treatments involving detergent/acids, the depth of penetration of chemicals in the clogged apertures and infiltration galleries/water channels etc. is limited.
The main objective of the present invention is to provide a non-toxic composition useful for cleaning/descaling of apertures/pipes which obviates the drawbacks of hitherto known such chemical compositions.
Another objective of the present invention is to provide a novel process of chemical-hydrofracturing for cleaning the clogged hand pumps and tube wells using the said non-toxic composition, which obviates the drawbacks of hitherto known processes of cleaning the wells either by physical methods or by chemical treatment.
Accordingly the present invention provides a process for preparation of a non-toxic synergistic composition useful for cleaning/descaling of apertures/pipes which comprises dissolving in water 1 to 25 wt% of edible acids selected from hydroxy and carboxylic organic acids such as tartaric, citric acid and 0.1 to 20 wt% polyphosphate based clay suspending/cleaning agent selected from di-sodium hydrogen phosphate, sodium hexametaphosphate and mixture thereof to make the final volume 100% to get desired non toxic synergistic composition.
The edible acids used may be such as hydroxy and carboxylic organic acids such as tartaric acid, citric acid or mixture thereof.
The poly phosphate based clay suspending/cleaning agent may be such as di-sodium hydrogen phosphate, sodium hexametaphosphate or mixture thereof.
The water used may be river, lake, tap or well water. Accordingly the present invention also provides a process for the cleaning/descaling of apertures/pipes which comprises clogged hand pumps and tube wells with above said non - toxic
composition at an applied pressure in the range of 0.1 to 1.0 bar for a period of 1 to 24 hours followed by hydrofracturing the well at a pressure in the range of 5- 800 bars followed by washing the well by injecting water.
This chemical-hydrofracturing process utilises the synergistic effect of treating clogged wells with non-toxic composition at an applied pressure and the high pressure-water hydrofracturing processes to achieve enhanced penetration and cleaning.
The non-toxic composition comprises of a mixture of one or more of the edible acids with clay and silt particle dispersing agent(s). This non-toxic composition is poured into the well after removing the metallic hand pump/tube well assembly and is allowed to react with the clogging materials for l to 24 hours duration under an applied pressure in the range of 0.1 to 1.0 bar. At the end of the reaction time, the well is hydrofractured by pumping-in water at a high pressure in the range 10 to SOO bars. After chemical-hydrof racturing, tie well is washed by purging with water. The clogging materials choking the apertures in the screens and slits of the pipe(s) are also cleaned using above formulation by brushing followed by washing with water. The cleaned metallic hand pump/tube well assembly is reinstalled in the cleaned well. The composition of the present invention is not merely a mixture but a synergistic mixture resulting in a composition having properties which are not merely an aggregation of the properties, but has synergistic properties which results in cleaning of clogged tube wells/hand pumps by
using said non-toxic composition.
The following examples are given by way of illustration of the present invention and should not be construed to limit the scope of the present invention.
EXAMPLE - 1
The aquifer and the metallic assembly of the hand pump located at Ratibarh village on Bhadbhada - Sehore road in Bhopal District were cleaned by the process of this invention. The diameter of the well was 12.5 cm and the depth was 65 meters. The static water level before cleaning was 31.5 meters and the water yield of the well was 1.4 liters per minute.
The non-toxic chemical cleaning solution was prepared by dissolving a mixture of 25 Kg tartaric acid and 4 Kg sodium hexametaphosphate in 150 liters of water. This solution was slowly poured in the well after removing the rods, cylinder and the pipes of the hand pump assembly. The inflatable rubber packer assembly was introduced in the well and inflated with air at a pressure of 300 bars to seal the well. After sealing the well, water was pumped into the well to create a positive pressure of 0.5 bar and left for a duration of four hours for reactions to take place between clogging materials and the cleaning solution. At the end of this reaction time, 1500 liters water was pumped in the well at high pressure in four minutes duration to hydrofracture the chemically treated aquifer apertures at a pressure of 40 bars. After abc-ve chemical -hydrof racturing, the well was back washed with water The metallic screen was cleaned by brushing with non-toxic chemsea. cleaning solution followed by
thorough washing with water. The hand pump was reassembled by putting back the rods, cylinder and pipes in the cleaned well. The static level of the water in the cleaned well was measured to be 11.0 meters with a water yield of 12.5 liters per minute.
EXAKFLE - 2 The aquifer and the metallic assembly of the hand pump located in the Sonkachha village of the Barasia tehsil under Bhopal District were cleaned by tfcui process of the invention. The diameter of the well was 12.5 cm and the depth was 95 meters. Before cleaning, the static water level was 6.4 meters and the water yield was 1.2 liters per minute.
The non-toxic chemical cleaning solution was prepared by dissolving 15 Kg. of citric acid. 20 Kg of tartaric acid and 5 Kg of sodium hexametaphospha*:e in 150 liters of water. This solution was slowly poured in the well after removing the rods, cylinder and the pipes of the hand pump assembly. The inflatable rubber packer assembly was introduced in the well and inflated with air at a pressure of 200 bar *;.o seal the well. After sealing the well, water was pumped into the well to create a positive pressure of 0.2 bar and left for a duration of four hours for reactions to take place between clogging materials and the cleaning solution. At the end of this reaction time, 1800 liters of water was pumped in the wc;ll at high pressure in six minutes duration to hydrofracture the chemically treated aquifer apertures at a pressure of 1C bars . After above chemical -hydrofracturing, the well was t-^ck washed with water.
The screen and the slits in the metal pipe were cleaned using the non-toxic chemical cleaning solution by brushing followed by thorough washing with water. The hand pump was then reassembled by putting back the rods, cylinder and pipes in the cleaned well. The static level of the water in the cleaned well was measured to be 3.0 meters with a water yield of 11.0 liters per minute.
The following are among the main advantages of the invention.
1. The process of cleaning the clogged hand pumps and tube wells described in the present invention makes use of synergistic effect of chemical reaction (of the cleaning formulation with clogging materials to dissolve some of its constituents and thus loosening the clogging material in the apertures) and applied pressure for hydrofracturing, in the presence of the non-toxic chemical composition solution to efficiently open the clogged aquifer apertures.
2. The chemical formulation ust.d in cleaning operation consists of one or more edible acids along with a clay and silt dispersing constituent, alL of which are of non-toxic nature.
3. The use of clay and si 11 dispersing constituent in the formulation reduces the tendency of fine sand and clay particles to settle in the bottom of the well during the back washing operation of the weLL.

We Claim:
1. A process for preparation of a non-toxic synergistic composition useful for cleaning/descaling of apertures/pipes which comprises dissolving in water 1 to 25 wt% of edible acids selected from hydroxy and carboxylic organic acids such as tartaric, citric acid and 0.1 to 20 wt% polyphosphate based clay suspending/cleaning agent selected from di-sodium hydrogen phosphate, sodium hexametaphosphate and mixture thereof to make the final volume 100% to get desired non toxic synergistic composition.
2. A process for preparation of non-toxic synergistic composition useful for cleaning/descaling apertures/pipes substantially as herein described with reference to the examples.

Documents:

651-del-1997-abstract.pdf

651-del-1997-claim.pdf

651-del-1997-complete specification (granted).pdf

651-del-1997-correspondence-others.pdf

651-del-1997-correspondence-po.pdf

651-del-1997-description (complete).pdf

651-del-1997-form-1.pdf

651-del-1997-form-19.pdf

651-del-1997-form-2.pdf

651-del-1997-form-3.pdf

651-del-1997-form-9.pdf

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Patent Number

193953

Indian Patent Application Number

651/DEL/1997

PG Journal Number

36/2004

Publication Date

04-Sep-2004

Grant Date

20-Jan-2006

Date of Filing

17-Mar-1997

Name of Patentee

COUNCIL OF SCEINTIFIC AND INDUSTRIAL RESEARCH

Applicant Address

RAFI MARG, NEW DELHI-110001, INDIA

Inventors:

#	Inventor's Name	Inventor's Address
1	SUDHIR SITARAM AMRITPHALE	REGIOINAL RESEARCH LABORATORY, BHOPAL - 462 026, (M.P.)INDIA
2	NAVIN CHANDRA	REGIOINAL RESEARCH LABORATORY, BHOPAL - 462 026, (M.P.)INDIA

PCT International Classification Number

C23G 1/02

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA