AU6490394A - Method of cleaning and maintaining potable water distribution pipe systems - Google Patents
Method of cleaning and maintaining potable water distribution pipe systemsInfo
- Publication number
- AU6490394A AU6490394A AU64903/94A AU6490394A AU6490394A AU 6490394 A AU6490394 A AU 6490394A AU 64903/94 A AU64903/94 A AU 64903/94A AU 6490394 A AU6490394 A AU 6490394A AU 6490394 A AU6490394 A AU 6490394A
- Authority
- AU
- Australia
- Prior art keywords
- acid
- solution
- scale
- pipe
- sediment
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000004140 cleaning Methods 0.000 title claims abstract description 40
- 238000000034 method Methods 0.000 title claims abstract description 32
- 238000009826 distribution Methods 0.000 title claims abstract description 29
- 235000012206 bottled water Nutrition 0.000 title claims abstract description 8
- 239000003651 drinking water Substances 0.000 title claims abstract description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 50
- 239000013049 sediment Substances 0.000 claims abstract description 29
- 230000002378 acidificating effect Effects 0.000 claims abstract description 16
- 238000011010 flushing procedure Methods 0.000 claims abstract description 6
- 239000000243 solution Substances 0.000 claims description 66
- 239000002253 acid Substances 0.000 claims description 32
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 18
- 239000000203 mixture Substances 0.000 claims description 18
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 13
- 229910052500 inorganic mineral Inorganic materials 0.000 claims description 10
- 239000011707 mineral Substances 0.000 claims description 10
- 150000007524 organic acids Chemical class 0.000 claims description 10
- 239000000344 soap Substances 0.000 claims description 10
- 229910021529 ammonia Inorganic materials 0.000 claims description 9
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 8
- 235000005985 organic acids Nutrition 0.000 claims description 7
- 239000002585 base Substances 0.000 claims description 6
- 239000003112 inhibitor Substances 0.000 claims description 6
- 239000002028 Biomass Substances 0.000 claims description 5
- 230000000149 penetrating effect Effects 0.000 claims description 5
- 239000004094 surface-active agent Substances 0.000 claims description 5
- 241000295146 Gallionellaceae Species 0.000 claims description 4
- 239000002738 chelating agent Substances 0.000 claims description 4
- 239000000654 additive Substances 0.000 claims description 3
- 150000001412 amines Chemical class 0.000 claims description 3
- 239000003795 chemical substances by application Substances 0.000 claims description 3
- 239000002270 dispersing agent Substances 0.000 claims description 3
- 239000000725 suspension Substances 0.000 claims description 3
- 239000008235 industrial water Substances 0.000 claims description 2
- 230000007935 neutral effect Effects 0.000 claims description 2
- 230000007928 solubilization Effects 0.000 claims description 2
- 238000005063 solubilization Methods 0.000 claims description 2
- 238000007789 sealing Methods 0.000 claims 3
- 241000894006 Bacteria Species 0.000 claims 1
- 230000000996 additive effect Effects 0.000 claims 1
- 239000003637 basic solution Substances 0.000 claims 1
- 238000005086 pumping Methods 0.000 claims 1
- AEMRFAOFKBGASW-UHFFFAOYSA-N Glycolic acid Chemical compound OCC(O)=O AEMRFAOFKBGASW-UHFFFAOYSA-N 0.000 description 16
- GSEJCLTVZPLZKY-UHFFFAOYSA-N Triethanolamine Chemical compound OCCN(CCO)CCO GSEJCLTVZPLZKY-UHFFFAOYSA-N 0.000 description 12
- 229960004275 glycolic acid Drugs 0.000 description 8
- 150000007513 acids Chemical class 0.000 description 7
- 238000005260 corrosion Methods 0.000 description 7
- 230000007797 corrosion Effects 0.000 description 7
- 239000007787 solid Substances 0.000 description 6
- -1 hydrochloric Chemical class 0.000 description 5
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 4
- WPYMKLBDIGXBTP-UHFFFAOYSA-N benzoic acid Chemical compound OC(=O)C1=CC=CC=C1 WPYMKLBDIGXBTP-UHFFFAOYSA-N 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 description 3
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 239000004615 ingredient Substances 0.000 description 3
- 238000009533 lab test Methods 0.000 description 3
- 238000004062 sedimentation Methods 0.000 description 3
- 229940048842 sodium xylenesulfonate Drugs 0.000 description 3
- QUCDWLYKDRVKMI-UHFFFAOYSA-M sodium;3,4-dimethylbenzenesulfonate Chemical compound [Na+].CC1=CC=C(S([O-])(=O)=O)C=C1C QUCDWLYKDRVKMI-UHFFFAOYSA-M 0.000 description 3
- 239000005711 Benzoic acid Substances 0.000 description 2
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 235000010233 benzoic acid Nutrition 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 150000007522 mineralic acids Chemical class 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 230000001737 promoting effect Effects 0.000 description 2
- 239000000523 sample Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- JOXIMZWYDAKGHI-UHFFFAOYSA-N toluene-4-sulfonic acid Chemical compound CC1=CC=C(S(O)(=O)=O)C=C1 JOXIMZWYDAKGHI-UHFFFAOYSA-N 0.000 description 2
- ZPEZUAAEBBHXBT-WCCKRBBISA-N (2s)-2-amino-3-methylbutanoic acid;2-amino-3-methylbutanoic acid Chemical compound CC(C)C(N)C(O)=O.CC(C)[C@H](N)C(O)=O ZPEZUAAEBBHXBT-WCCKRBBISA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- ULUAUXLGCMPNKK-UHFFFAOYSA-N Sulfobutanedioic acid Chemical class OC(=O)CC(C(O)=O)S(O)(=O)=O ULUAUXLGCMPNKK-UHFFFAOYSA-N 0.000 description 1
- 241000153282 Theope Species 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 150000001447 alkali salts Chemical class 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- 125000000129 anionic group Chemical group 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 125000002091 cationic group Chemical group 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000012141 concentrate Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- ZBCBWPMODOFKDW-UHFFFAOYSA-N diethanolamine Chemical compound OCCNCCO ZBCBWPMODOFKDW-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000003995 emulsifying agent Substances 0.000 description 1
- 150000002191 fatty alcohols Chemical class 0.000 description 1
- 239000013505 freshwater Substances 0.000 description 1
- 231100000206 health hazard Toxicity 0.000 description 1
- 239000003752 hydrotrope Substances 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000003973 irrigation Methods 0.000 description 1
- 230000002262 irrigation Effects 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000011572 manganese Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- MGFYIUFZLHCRTH-UHFFFAOYSA-N nitrilotriacetic acid Chemical compound OC(=O)CN(CC(O)=O)CC(O)=O MGFYIUFZLHCRTH-UHFFFAOYSA-N 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 150000003014 phosphoric acid esters Chemical class 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 239000003352 sequestering agent Substances 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 235000000346 sugar Nutrition 0.000 description 1
- 150000008163 sugars Chemical class 0.000 description 1
- 150000003871 sulfonates Chemical class 0.000 description 1
- 239000012085 test solution Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B08—CLEANING
- B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
- B08B9/00—Cleaning hollow articles by methods or apparatus specially adapted thereto
- B08B9/02—Cleaning pipes or tubes or systems of pipes or tubes
- B08B9/027—Cleaning the internal surfaces; Removal of blockages
- B08B9/032—Cleaning the internal surfaces; Removal of blockages by the mechanical action of a moving fluid, e.g. by flushing
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
- C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
- C11D7/02—Inorganic compounds
- C11D7/04—Water-soluble compounds
- C11D7/08—Acids
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
- C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
- C11D7/22—Organic compounds
- C11D7/26—Organic compounds containing oxygen
- C11D7/265—Carboxylic acids or salts thereof
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
- C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
- C11D7/22—Organic compounds
- C11D7/32—Organic compounds containing nitrogen
- C11D7/3218—Alkanolamines or alkanolimines
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
- C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
-
- E—FIXED CONSTRUCTIONS
- E03—WATER SUPPLY; SEWERAGE
- E03B—INSTALLATIONS OR METHODS FOR OBTAINING, COLLECTING, OR DISTRIBUTING WATER
- E03B7/00—Water main or service pipe systems
- E03B7/006—Arrangements or methods for cleaning or refurbishing water conduits
-
- C—CHEMISTRY; METALLURGY
- C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
- C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
- C11D2111/00—Cleaning compositions characterised by the objects to be cleaned; Cleaning compositions characterised by non-standard cleaning or washing processes
- C11D2111/10—Objects to be cleaned
- C11D2111/14—Hard surfaces
- C11D2111/20—Industrial or commercial equipment, e.g. reactors, tubes or engines
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Life Sciences & Earth Sciences (AREA)
- Wood Science & Technology (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Mechanical Engineering (AREA)
- Health & Medical Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Materials Engineering (AREA)
- General Chemical & Material Sciences (AREA)
- Metallurgy (AREA)
- Emergency Medicine (AREA)
- Inorganic Chemistry (AREA)
- Public Health (AREA)
- Water Supply & Treatment (AREA)
- Cleaning In General (AREA)
- Cleaning By Liquid Or Steam (AREA)
- Detergent Compositions (AREA)
- Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
A method of cleaning and maintaining potable water distribution system which have reduced flow due to an increase of water scale deposits, sediment, and the like on the inside surface of the pipe is disclosed. An aqueous acidic cleaning solution (12) is introduced and circulated through the pipe (25) to be treated for a sufficient time to dissolve and loosen the scale and sediment, and the spent solution containing dissolved or suspended scale and sediment is flushed from the pipe (25) to provide a cleaned pipe with improved water flow. It is also desirable to flush the water distribution pipe system with high pressure water after the treatment to remove loosened scale and sediment that was not removed during the circulation and flushing of the treating solution (12).
Description
METHOD OF CLEANING AND MAINTAINING POTABLE WATER DISTRIBUTION PIPE SYSTEMS
RELATED APPLICATIONS
This application is a continuation-in-part of Application Serial No. 08/036,188, filed March 23, 1993, and also claims the benefit of Application Serial No. 07/700,780, filed May 16, 1991, and the disclosures of both of these applications are incorporated herein in their entireties by reference. BACKGROUND OF THE INVENTION
It is well known that hardness and suspended solids in water sources vary widely in composition depending on the source and will result in scale deposition and sedimentation on surfaces wherever water is used. Scale deposition and sedimentation is particularly troublesome in water distribution pipe systems which service the residential and commercial customers of municipalities, private water companies and the like along with industrial process water distribution pipe systems as found in the mining, petroleum, agriculture and the like industries. In these systems, the formation of scale and sediment can
reduce the water flow through the pipe system whic will limit the capacity of the pipe to service the requirements of the customers or to provide the required water necessary for an industrial process, irrigation, etc. For instance, in municipal systems an increase in the fire risk would be obvious if the fire hydrant did not supply sufficient water to extinguish the fire due to scale and sediment deposits in the feed pipe line. At some point, the water distribution pipe would have to be replaced due to these restrictions at a high cost and with prolonged interruption of service.
Additionally, scale and sedimentation will increase the possibility of corrosion in the water distribution pipe along with promoting the growth of organisms. The organisms also can be a health hazard, promoting corrosion and biomass which binds scale and sediment together and to the surfaces of the system. Corrosion will eventually lead to the leakage of the system and the necessity to replace the leaking section.
Strong acids have been used to clean water wells, however, submersible pumps are removed prior to treatment to prevent corrosion by the acids employed. Also, organic acids, mixtures of mineral acids and organic acids or inhibited acid compositions have been found to clean water wells without the necessity of removing the pumps or other equipment. These methods
for cleaning water wells have involved static an surging treatment.
A proper cleaning and maintenance program fo water distribution systems will prevent decreased wate flow capacity, corrosion and the necessity to replac the system or portions thereof. A simple and effectiv method for cleaning and maintaining these systems i needed. SUMMARY OF THE INVENTION This invention is directed to a method o cleaning and maintaining water distribution systems Water systems having interior scale and sedimen deposits are cleaned by introducing and circulating a effective amount of an aqueous treatment solution fo a sufficient period of time which results in th solution, loosening and suspension of the undesire scale and sediment. Thereafter, the spent treatin solution containing the dissolved or suspended scal and sediment is flushed from the water distributio system to provide a clean system with improved wate flow and operation. Additionally, further flushin with high pressure water will also remove additiona scale that had been loosened by the treating solution.
The cleaning solution may be acidic, neutra or basic. In the most preferred form, in potable wate pipe systems, mineral acids or organic acids, an mixtures thereof, are employed as acidic treatmen solutions. The acidic treatment solution may contai
further additives such as inhibitors, chelating agents, penetrating and/or dispersing agents to assist in the removal of scale and sediment and to minimize any adverse effects on the pipes, valves, or other system surfaces due to the acids employed.
This invention provides a simple, low cost and effective method of removing water scale and sediment from water distribution systems in order to maintain proper water flow, operation and to prevent corrosion of the system which would require the high cost and inconvenience of replacement.
Other advantages and objectives of this invention will be further understood with reference to the following detailed description and drawings. DETAILED DESCRIPTION OF THE INVENTION
Among the acidic treatment solutions found to be useful in practicing the method of this invention are aqueous solutions of mineral acids such as hydrochloric, nitric, phosphoric, polyphosphoric, hydrofluoric, boric, sulfuric, sulfurous, and the like. Aqueous solutions of mono-, di- and polybasic organic acids have also been found to be useful and include formic, acetic, propionic, citric, glycolic, lactic, tartaric, polyacrylic, succinic, p-toluenesulfonic, and the like. The useful treatment solutions may also be aqueous mixtures of the above mineral and organic acids.
Alkaline, acid, or neutral cleaning solutions may also be employed, as indicated above, dependin upon the type of scale that needs to be removed. Sequestering or chelating agents such as EDT (ethylenediamine tetraacetic acid) , NT (nitrilotriacetic acid), and derivatives, i.e., basic alkali salts, and the like have also been found to be useful in the treatment solution in certain cases.
The acidic treatment solution may also contain acid inhibitors which substantially reduce the acidic action on metal surfaces of the water distribution system, particularly valves, fire hydrants, etc. , and these various inhibitors for acids have been well documented in the patent art. Typical, but not necessarily all inclusive, examples of acid inhibitors are disclosed in the following U.S. Patents:
2,758,970; 2,807,585; 2,941,949; 3,077,454; 3,607,781;
3,668,137; 3,885,913; 4,089,795; 4,199,469; 4,310,435;
4,541,945; 4,554,090; 4,587,030; 4,614,600; 4,637,899; 4,670,186; 4,780,150 and 4,851,149 which are incorporated herein by reference.
The treatment solution may also contain dispersing, penetrating or emulsifying agents to assist in the removal of the scale and sediment. These surface active agents may be anionic, cationic, nonionic or amphoteric as defined in the art. Compounds such as alkyl ether sulfates, alkyl or aryl sulfates, alkanolamines, ethoxylated alkanolamides,
a ine oxides, ammonium and alkali soaps, betaines, hydrotropes such as sodium aryl sulfonates; ethoxylated and propoxylated fatty alcohols and sugars, ethoxylated and propoxylated alkylphenols, sulfonates, phosphate esters, quarternaries, sulfosuccinates, and mixtures thereof, have been found to be useful in admixture with the acid treating solution. DRAWINGS AND OPERATING EXAMPLES
Fig. 1 is a schematic of a laboratory test system illustrating the method of this invention.
Fig. 2 is a diagram of a field system for cleaning a potable water distribution system.
With reference to Fig. 1, a laboratory test system is shown to evaluate the removal of scale and sediment by acidic treating solutions from a test pipe sample taken from a water distribution system. This system includes a 15 gallon acidic treating solution reservoir 5, submersible acidic treating solution circulation pump 6 rated at 1200 gallons per hour, 1" inlet transfer line 7, drain valve 8, heavy rubber diaphragm seals 9 for the ends of the test pipe specimen 10, 1" outlet transfer line 11 and the treating solution 12. The test pipe specimen 10 is mounted at about a 30 degree angle so that the test solution will contact essentially the entire inner pipe surface to be treated.
A laboratory test, for example, was run on a four foot section of 6" diameter pipe which had been
removed from a potabl i water distribution system tha had been used for over 40 years. The scale on th inside of the pipe consisted of nodules of up to 1 t 1% inches in height covering 100% of the inside pip surface which had substantially reduced the openin inside the pipe for water to flow. Analysis of th scale indicated it consisted of primarily iron wit some calcium, magnesium and manganese in the for oxides, hydroxides and carbonates along with fin mineral acid insoluble solids and some "biomass". This is typical scale associated with sulfate-reducing an iron bacteria along with the associated corrosion.
About 10 gallons of a 12.5% aqueous inhibite hydrochloric/glycolic acid solution containing penetrating agent was placed in the reservoir 5 an circulated through the test pipe 10 for a period of 24 hours. After 2 hours of circulation, particles of th scale were breaking loose and could be heard in th outlet transfer line 11 and observed entering th reservoir 5. The color of the treating solution als became increasingly darker with circulation time. After 24 hours the circulation was stopped and th system was drained of the treating solution. Th diaphragms 9 were removed and the inside of the tes p pe was observed to be about 80% cleaned of scale an sediment solids.
On treating the test pipe with a secon identical treating solution for a period of 21.5 hours.
about 80% of the interior surface of the test pipe wa observed to still be covered over with a scale and/o sediment that was a soft and paste-like semi-soli which contained some grit and could be easily remove with a probe. The remaining scale nodules had bee substantially reduced in size since the end of th first treatment. It was concluded that the secon treatment would probably not be necessary if a hig pressure water flush was employed to remove th insoluble soft sediment which had coated the remainin scale nodules after the first treatment.
With reference to Fig. 2, a field equipment and system diagram is shown which may be employed i the cleaning of a potable water pipe distributio system. Two 500 gallon treating solution reservoir tanks 20 and 21 along with a 100 gallon per minut circulation pump 22 and sight glass 23 are mounted o a flat bed truck (not shown) . In this example, a 2% inlet pipe 24 is secured to a 650 foot section of 6" water distribution pipe 25 after the main shut off valve 26. The fire hydrant 27 and fire hose 28 were employed for the acidic treating solution return to tanks 20 and 21.
The section of pipe 25 to be treated was isolated by closing off the two water main shut-off valves 26 and 29 along with all service line valves, typically 30 and 31. With valves 32 and 33 closed, 1000 gallons of acidic treating solution was prepared
in tanks 20 and 21. With the coupling 34 open, th treating solution was allowed to enter the system b opening valves 33 and 35 and turning on the circulatio pump 22. The pH of the water coming from the ope coupling was then monitored until a decrease was note which indicated the acid treating solution ha displaced the water in the section to be treated. Th circulation pump 22 was turned off and the coupling 34 connected. Valves 36 and 37 were then closed and valv 32 opened for circulation. The circulation pump 22 was then started again for the treatment period. Valve 37 was closed to allow for scale solids to accumulate i tank 20 while the treating solution could overflow a 38 to tank 21 which reduces the chances of pluggin during treatment.
The treating solution was then circulated i the system of Fig. 2 for a period of 5 hours. Observation of the treating solution through the sigh glass 23 showed an increasingly darker discoloratio with time. At the end of the treatment period, th circulation pump 22 was turned off, and valves 33 an 35 were closed. The main shut-off valve 26 was slowl opened and fresh water allowed to enter the syste until the treating solution was displaced as noted whe the tanks 20 and 21 were full. Valve 32 was the closed. The fire hose 28 was then disconnected fro the fire hydrant 27 and the main shut-off valve 2 opened full to allow high pressure flushing of th
treated water main 25. As the flush water emerged fr the fire hydrant 27 it was dark in color wi considerable scale and sediment solids. Flushi continued until the flush water was clean of solids f 5 a period of time prior to putting the treated secti of the water distribution system back into service.
The flow rate through the fire hydrant 2 prior to treatment had been determined by a Pitot Gau to be 588 gallons per minute. After treatment, t
10 flow rate was determined to be 790 gallons per minute This was an increase of 34.5%.
Also, improved mechanical operations of t hydrants and valves of the system were achieved. T flow of cleaning solution may also be reversed in t
15 system to further improve cleaning efficiency. T above cleaning solutions met the requirements of t National Sanitation Foundation (NSF International, A Arbor, Michigan) . Standard 60 for potable wate distribution systems.
20 Other examples of cleaning solutions may employed as follows:
Preblend Ingredients % bv wt
31% Hydrochloric acid in water 87.14 +/- 2%
70% Glycolic acid in water 5.27 +/- 0.3%
25 40% Sodium xylene sulfonate in water 2.06 +/- 0.2%
Triethanolamine and diethanolamine 2.96 +/- 0.2% mixture (85%/15%)
Water 2.57 +/- 0.2%
In a preferred form of the invention, th
30 above preblended cleaning solution is used in an amoun of about 12.5% by weight with water in the field fo
cleaning an underground potable water distribution pip system. However, more generally, the solution may b employed in amounts of from about 5 to about 50% b weight with water in the field, depending upon suc variables as the amount of scale, pipe volume to b cleaned, circulation time and other factors. Th amounts of anhydrous chemicals in a broader range o ingredients are about 1% to 27% HC1, 0.1% to 4 glycolic acid, 0.04% to 1% sodium xylene sulfonate an a b o u t 0 . 1 % t o 2 . 5 % o f t h triethanolamine/diethanolomine mixture (hereinafte referred to as "TEA") .
It should be understood that the abov chemical ingredients may be blended in the field fo cleaning the underground potable pipes, for example, hydrochloric acid may be added to a concentrate of th glycolic acid, sodium xylene sulfonate and TEA. In th potable water distribution systems, an undergroun section of the pipe to be cleaned is sealed off fro the rest of the system. As illustrated above in Fig. 2, the cleaning solution is then introduced from a tan into the pipe section and, if water is in that sectio of pipe, it is removed upon the introduction of th cleaning solution. After the cleaning solution ha been introduced into the pipe section, circulation o the cleaning solution through the underground pipe i initiated for a sufficient period of time fo
solubilization, loosening and/or suspension of th scale and sediments.
In the above preblends, a soap having a 1:1 stoichiometric equivalent of the acid (HC1 and glycolic acid) and TEA base is formed with an excess of the acid. This composition has been found to work effectively in the field for the removal of scale associated with sulfate-reducing and iron bacteria consisting primarily of iron oxide, biomass and sediment. These 1:1 soaps have also been described in the above referred to co-pending Application Serial No. 07/700,780, filed May 16, 1991, now U.S. Patent No. and the disclosure thereof is incorporated herein in its entirety by reference. These soaps may be more generally categorized as soaps of mineral and/or organic acids and a base such as an amine and ammonia. Further examples of these soaps include 1:1 soaps of TEA and glycolic acid (also known as hydroxyacetic acid) ; TEA and acetic acid; TEA and citric acid; TEA and benzoic acid; hydrochloric acid and ammonia; sulfuric acid and ammonia; nitric acid and ammonia; TEA and hydrochloric acid; TEA and sulfuric acid; TEA and nitric acid; ammonia and glycolic acid; ammonia and benzoic acid; and ammonia and p- toluenesulfonic acid. Accordingly, it will be understood that other cleaning solutions of the acidic type employing 1:1 soaps may be employed to effectively solubilize, loosen and/or suspend the scale and
sediment from the potable pipe in accordance with th principles of this invention.
In view of the above detailed description other method variations to clean domestic an industrial water distribution systems, like houses hotels, plants, offices, etc., will be apparent to person of ordinary skill in the art without departin from the scope of this invention. The method i especially advantageous in cleaning underground potabl water distribution systems having scale associated wit sulfate-reducing and iron bacteria consisting primaril of iron oxide, biomass and sediment.
What is claimed is:
Claims (1)
- (1) A method for cleaning a potable wate distribution system comprising introducing an effective amount of an aqueous cleaning solution for the removal of scale associate with sulfate-reducing and iron bacteria consistin primarily of iron oxide, biomass and sediment fro inside surfaces of a potable water distribution system, said solution selected from the group consisting of acidic, neutral and basic solution, sealing off a section of pipe in said system for circulation of said cleaning solution therethrough, circulating said cleaning solution through said pipe system for a sufficient period of time for solubilization, loosening and/or suspension of said scale and sediment, flushing said cleaning solution containing solubilized, loosened or suspended scale and sediment from said system.(2) The method of claim 1 comprising the furthe step of flushing said system with clean water after th removal of the spent cleaning solution.(3) The method of claim 1 comprising the furthe step of flushing said system with high pressure wate for the removal of any spent cleaning solution, scal and/or sediment.(4) The method of claim 1 wherein said aqueou treatment solution is acidic.(5) The method of claim 4 wherein said aci solution contains further additives selected from th group consisting of acid inhibitors, chelating agents, surfactants, penetrating agents and dispersing agents, and mixtures thereof to assist in the removal of sai scale and sediment.(6) The method of claim 4 wherein said acid i selected from the group consisting of mineral an organic acids and mixtures thereof.(7) The method of claim 6 wherein said minera acid is selected from the group consisting o hydrochloric, nitric, phosphoric, polyphosphoric, hydrofluoric, boric, sulfuric, and sulfurous, an mixtures thereof. (8) The method of claim 6 wherein said organi acid is selected from the group consisting of formic acetic, propionic, citric, glycolic, lactic, tartaric polyacrylic, succinic, p-toluenesulfonic, and mixture5 thereof.(9) The method of claim 6 wherein said solutio further contains an additive from the group consistin of acid inhibitors, chelating agents, surfactants penetrating agents and dispersing agents, and mixture10 thereof to assist in the removal of said scale an sediment.(10) The method of claim 1 wherein said cleanin solution is a mixture of hydrochloric acid, glycoli acid, and alkanolamine and a surfactant.15 (11) The method of claim 10 wherein said mixtur is employed in a preblend as the aqueous cleanin solution.(12) The method of claim 1 wherein said cleanin solution contains a soap having a 1:1 stoichiometri equivalent of an acid and a base wherein said acid i selected from the group consisting a mineral acid an an organic acid and said base is selected from a grou consisting of an amine and ammonia, where an effectiv amount of free acid is present in the solution to reac with said scale.(13) A method for cleaning a potable wate distribution pipe system comprising providing a reservoir for containing a aqueous acidic cleaning solution for the removal o scale associated with sulfate-reducing and iro bacteria consisting primarily of iron oxide, biomas and sediment from inside pipe surfaces of a potabl water distribution pipe system, sealing off a section of pipe in said syste for circulation of said cleaning solution therethrough circulating said cleaning solution from sai reservoir through said pipe section and returning sai solution to said reservoir for the removal of sai scale and sediment.(14) The method of claim 13 wherein said cleanin solution is a mixture of hydrochloric acid, glycoli acid, and alkanolamine and a surfactant.(15) The method of claim 13 wherein said cleanin solution contains a soap having a 1:1 stoichiometri equivalent of an acid and a base wherein said acid i selected from the group consisting a mineral acid an an organic acid and said base is selected from a grou consisting of an amine and ammonia, where an effectiv amount of free acid is present in the solution to reac with said scale. (16) The method of claim 13 wherein said reservoir is truck mounted for makeup, storage and disposal of cleaning solution.(17) The method of claim 13 by sealing said pipe section between two fire hydrants and circulating said cleaning solution by connecting one of said fire hydrants to said reservoir for pumping said cleaning solution therethrough.(18) The method of claim 13 wherein said pipe distribution system is domestic or industrial water distribution system.(19) The method of claim 13 comprising the further step of flushing said pipe system with clean water after the removal of spent cleaning solution.(20) A method of claim 15 wherein said mineral acid is selected from a group consisting of hydrochloric, nitric, phosphoric, polyphosphoric, hydrofluoric, boric, sulfuric and sulphurous, mixtures thereof, and said organic acid as selected from the group consisting of formic, acetic, propionic, citric, glycolic, lactic, tartaric, polyacrylic, succinic, poly-toluenesulfonic and mixtures thereof. (21) The method of claim 13 wherein said aqueo treatment solution meets the requirements of t National Sanitation Foundation Standard 60 for potabl water distribution systems.
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US036188 | 1993-03-23 | ||
US08/036,188 US5360488A (en) | 1993-03-23 | 1993-03-23 | Method of cleaning and maintaining water distribution pipe systems |
US20995394A | 1994-03-17 | 1994-03-17 | |
US209953 | 1994-03-17 | ||
PCT/US1994/003065 WO1994021865A1 (en) | 1993-03-23 | 1994-03-22 | Method of cleaning and maintaining potable water distribution pipe systems |
Publications (2)
Publication Number | Publication Date |
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AU6490394A true AU6490394A (en) | 1994-10-11 |
AU673426B2 AU673426B2 (en) | 1996-11-07 |
Family
ID=26712917
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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AU64903/94A Ceased AU673426B2 (en) | 1993-03-23 | 1994-03-22 | Method of cleaning and maintaining potable water distribution pipe systems |
Country Status (8)
Country | Link |
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EP (1) | EP0690944B1 (en) |
JP (1) | JP3597193B2 (en) |
AT (1) | ATE170583T1 (en) |
AU (1) | AU673426B2 (en) |
BR (1) | BR9406139A (en) |
CA (1) | CA2157916C (en) |
DE (1) | DE69413017T2 (en) |
WO (1) | WO1994021865A1 (en) |
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---|---|---|---|---|
WO1995035419A1 (en) * | 1994-06-20 | 1995-12-28 | H.E.R.C. Products Incorporated | Method of cleaning and maintaining potable water distribution pipe systems with a heated cleaning solution |
US5755155A (en) * | 1997-02-28 | 1998-05-26 | Tetra Laval Holdings & Finance S.A. | Aseptic process interface group |
JPH11141713A (en) * | 1997-09-05 | 1999-05-28 | Tetra Laval Holdings & Finance Sa | Sterile valve assembly |
JP2002052322A (en) * | 2000-08-10 | 2002-02-19 | Kurita Water Ind Ltd | Washing method |
JP4283098B2 (en) * | 2003-12-04 | 2009-06-24 | 花王株式会社 | Metal component processing solution |
JP5200326B2 (en) * | 2006-03-30 | 2013-06-05 | 栗田工業株式会社 | Scale cleaner and scale removal method |
WO2016068525A1 (en) * | 2014-10-27 | 2016-05-06 | 이기원 | Method for removing scale |
RU2594426C1 (en) * | 2015-02-26 | 2016-08-20 | Акционерное общество "Научно-исследовательский и проектный институт по переработке газа" (АО "НИПИгазпереработка") | Method for cleaning inner surface of process equipment and pipelines (versions) |
CA2969174A1 (en) | 2017-06-02 | 2018-12-02 | Fluid Energy Group Ltd. | Novel modified acid compositions as alternatives to conventional acids in the oil and gas industry |
DE202019003089U1 (en) * | 2019-07-24 | 2020-10-27 | Josef Schallameier | Decalcification of pressurized pipes of any length |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3667487A (en) * | 1970-12-11 | 1972-06-06 | Richardson Chem Cleaning Servi | Integrated chemical cleaning apparatus |
US4025359A (en) * | 1974-04-01 | 1977-05-24 | Connelly Jr George F | Inhibited acid composition for cleaning water systems |
DE3066305D1 (en) * | 1979-10-24 | 1984-03-01 | Fischer Ag Georg | Method and apparatus for rinsing, cleaning, disinfecting and coating a conduit on the interior, especially a water conduit in a new construction |
DE3244443C2 (en) * | 1982-12-01 | 1986-11-06 | Späne, Rainer, 7888 Rheinfelden | Process for removing iron, calcium and manganese-containing ocher deposits and / or sintering from facilities operated for water supply |
EP0183894B1 (en) * | 1984-11-30 | 1991-07-24 | Feldmann-Chemie GmbH | Use of mixture of acids and/or acid salts for removing iron and manganese deposits and stains |
FR2602571B1 (en) * | 1986-08-06 | 1989-02-03 | Assainissement Rationnel Pompa | METHOD FOR CLEANING A PIPELINE, PARTICULARLY OF A DRINKING WATER DISTRIBUTION NETWORK AND SYSTEM FOR CARRYING OUT SAID METHOD |
DE3631459A1 (en) * | 1986-09-16 | 1988-03-24 | Wegener Paul | METHOD FOR CLEANING THE INTERIOR OF BRANCHED PIPELINES AND / OR AGGREGATES AND DEVICE FOR CARRYING OUT THIS METHOD |
DE3731441A1 (en) * | 1987-08-13 | 1989-02-23 | Imhof Elisabeth | Process and device for cleaning, corrosion removal, descaling if appropriate, and sealing of building water installations |
DE3828229A1 (en) * | 1988-08-19 | 1990-02-22 | Feldmann Chemie Gmbh | Means for cleaning, disinfection and maintaining drinking water plants and beverage industry plants |
DE4015202A1 (en) * | 1990-05-11 | 1991-11-14 | Heimo Wessollek | CLEANER FOR DRINKING WATER SYSTEMS |
DE4015201A1 (en) * | 1990-05-11 | 1991-11-14 | Heimo Wessollek | CLEANER FOR DRINKING WATER SYSTEMS |
US5322635A (en) * | 1991-05-16 | 1994-06-21 | H.E.R.C. Incorporated | Soap compositions of carboxylic acids and amines useful in removal and prevention of scale |
DE4125315C2 (en) * | 1991-07-31 | 1995-09-28 | Oertzen Arndt H Gmbh & Co | Device for cleaning pipelines |
-
1994
- 1994-03-22 WO PCT/US1994/003065 patent/WO1994021865A1/en active IP Right Grant
- 1994-03-22 EP EP94912283A patent/EP0690944B1/en not_active Expired - Lifetime
- 1994-03-22 BR BR9406139A patent/BR9406139A/en not_active IP Right Cessation
- 1994-03-22 DE DE69413017T patent/DE69413017T2/en not_active Expired - Fee Related
- 1994-03-22 CA CA002157916A patent/CA2157916C/en not_active Expired - Fee Related
- 1994-03-22 AT AT94912283T patent/ATE170583T1/en active
- 1994-03-22 JP JP52131394A patent/JP3597193B2/en not_active Expired - Fee Related
- 1994-03-22 AU AU64903/94A patent/AU673426B2/en not_active Ceased
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WO1994021865A1 (en) | 1994-09-29 |
AU673426B2 (en) | 1996-11-07 |
JP3597193B2 (en) | 2004-12-02 |
EP0690944B1 (en) | 1998-09-02 |
JPH08509908A (en) | 1996-10-22 |
ATE170583T1 (en) | 1998-09-15 |
DE69413017T2 (en) | 1999-01-28 |
CA2157916C (en) | 2000-01-25 |
DE69413017D1 (en) | 1998-10-08 |
EP0690944A1 (en) | 1996-01-10 |
BR9406139A (en) | 1996-01-30 |
CA2157916A1 (en) | 1994-09-29 |
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