GB2451163A - Removal of combustion deposits - Google Patents
Removal of combustion deposits Download PDFInfo
- Publication number
- GB2451163A GB2451163A GB0810744A GB0810744A GB2451163A GB 2451163 A GB2451163 A GB 2451163A GB 0810744 A GB0810744 A GB 0810744A GB 0810744 A GB0810744 A GB 0810744A GB 2451163 A GB2451163 A GB 2451163A
- Authority
- GB
- United Kingdom
- Prior art keywords
- boiler
- sodium bicarbonate
- solution
- combustion
- cleaning agent
- 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
- 238000002485 combustion reaction Methods 0.000 title claims abstract description 20
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 claims abstract description 30
- 238000000034 method Methods 0.000 claims abstract description 23
- 229910052751 metal Inorganic materials 0.000 claims abstract description 22
- 239000002184 metal Substances 0.000 claims abstract description 22
- 239000012459 cleaning agent Substances 0.000 claims abstract description 21
- 239000000243 solution Substances 0.000 claims abstract description 21
- 229910000030 sodium bicarbonate Inorganic materials 0.000 claims abstract description 15
- 235000017557 sodium bicarbonate Nutrition 0.000 claims abstract description 15
- 239000000080 wetting agent Substances 0.000 claims abstract description 12
- UIIMBOGNXHQVGW-DEQYMQKBSA-M Sodium bicarbonate-14C Chemical compound [Na+].O[14C]([O-])=O UIIMBOGNXHQVGW-DEQYMQKBSA-M 0.000 claims abstract description 9
- 239000000049 pigment Substances 0.000 claims abstract description 8
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 claims abstract description 7
- 150000003754 zirconium Chemical class 0.000 claims abstract description 7
- 239000007864 aqueous solution Substances 0.000 claims abstract description 6
- 230000002378 acidificating effect Effects 0.000 claims abstract description 5
- 239000000567 combustion gas Substances 0.000 claims abstract description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 9
- 239000004615 ingredient Substances 0.000 claims description 7
- 238000004140 cleaning Methods 0.000 claims description 6
- 239000007787 solid Substances 0.000 claims description 4
- 239000002253 acid Substances 0.000 claims description 3
- 239000007921 spray Substances 0.000 claims description 3
- 239000003599 detergent Substances 0.000 description 10
- 239000003921 oil Substances 0.000 description 7
- 239000000446 fuel Substances 0.000 description 5
- 238000012423 maintenance Methods 0.000 description 4
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 3
- 239000003945 anionic surfactant Substances 0.000 description 3
- 239000012141 concentrate Substances 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000002736 nonionic surfactant Substances 0.000 description 3
- 238000005507 spraying Methods 0.000 description 3
- 239000005864 Sulphur Substances 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 239000002283 diesel fuel Substances 0.000 description 2
- 235000013305 food Nutrition 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 1
- 229920002472 Starch Polymers 0.000 description 1
- 239000004480 active ingredient Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 125000000129 anionic group Chemical group 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000001680 brushing effect Effects 0.000 description 1
- 239000001768 carboxy methyl cellulose Substances 0.000 description 1
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 1
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 239000003093 cationic surfactant Substances 0.000 description 1
- 238000006731 degradation reaction Methods 0.000 description 1
- 230000002939 deleterious effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 235000014113 dietary fatty acids Nutrition 0.000 description 1
- 239000000194 fatty acid Substances 0.000 description 1
- 229930195729 fatty acid Natural products 0.000 description 1
- 150000004665 fatty acids Chemical class 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000003546 flue gas Substances 0.000 description 1
- 239000000295 fuel oil Substances 0.000 description 1
- 230000003116 impacting effect Effects 0.000 description 1
- 206010022000 influenza Diseases 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 239000003350 kerosene Substances 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000007790 scraping Methods 0.000 description 1
- 239000000344 soap Substances 0.000 description 1
- 239000004071 soot Substances 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- XJUNLJFOHNHSAR-UHFFFAOYSA-J zirconium(4+);dicarbonate Chemical compound [Zr+4].[O-]C([O-])=O.[O-]C([O-])=O XJUNLJFOHNHSAR-UHFFFAOYSA-J 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24D—DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR
- F24D19/00—Details
- F24D19/0092—Devices for preventing or removing corrosion, slime or scale
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
- F24H9/00—Details
- F24H9/0005—Details for water heaters
- F24H9/0042—Cleaning arrangements
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Detergent Compositions (AREA)
- Cleaning By Liquid Or Steam (AREA)
Abstract
A method of removing sulphide combustion deposit from at least one heated metal surface exposed to combustion gases in a boiler 2 includes opening a port in the boiler to permit access to the metal surface. A non-acidic cleaning agent 1 of ammonium-free, non-effervescent solution of sodium bicarbonate is sprayed onto the heated surface/s. The solution also includes a wetting agent. Application of the solution permits the loosened combustion deposit to exhaust from the boiler via an exhaust flue. A further combination includes sodium bicarbonate, a dye or pigment for the sodium bicarbonate, an aqueous wetting agent and optionally a zirconium salt, for use in forming an aqueous solution for removal of sulphide combustion products from heated metal surfaces of domestic oil-fired pressure jet boilers.
Description
Removal of combustion deposits The present invention concerns a method of removal of combustion deposits from metal surfaces of boilers, such as domestic oil-fired pressure jet boilers (including condensing boilers).
Domestic oil-fired pressure jet boilers are generally fired in UK by kerosene or the like; they can also be fired by oils such as diesel oil or mazut (a heavy, lower quality fuel oil, often used to blend with other oils to form diesel oil).
Suiphide deposits formed by combustion of oil in domestic oil-fired pressure jet boilers tend to build up on various metal surfaces within the boiler. The actual location of deposit build-up depends upon the boiler design: the amount and nature of the deposits depend on the nature of the fuel and fuel consumption. The deposits (depending on the type of fuel) typically include sulphur, sulphur compounds, soot and metal ash. The thermal performance of a domestic oil-fired pressure-jet boiler depends on efficient heat transfer from hot burner gasses through the metal surfaces. Such deposits can adversely affect such heat transfer; they can also cause gas flow passages to become obstructed or restricted.
Such problems lead to heat wastage because much of the heat generated by combustion of the oil is lost, resulting merely in disadvantageous raising of the flue gas temperature. Conventional brushing and scraping during maintenance cycles do not fully remove such deposits.
Furthermore, when a boiler is not adequately cleaned, and is then brought back into service after such inadequate cleaning, residual deposit not cleaned away acts as a base for the formation of new deposits. These new deposits therefore form much faster than would be the case with properly cleaned boiler tubes.
Finally, largely because of the sulphur content of the fuel, the usual environment within a domestic oil-fired pressure jet boiler is acidic, which tends to accelerate corrosion of metal parts within the boiler. This is particularly true when the fuel is diesel or mazut.
The present invention provides an improved method for removing of sulphide combustion deposit from at least one heated metal surface in the interior of a boiler, which surface in use is exposed to combustion gases and heated thereby.
The method according to the invention comprises: (a) opening a port in the boiler to permit access to the heated metal surface in the interior of the boiler, and (b) directing a spray of non-acidic cleaning agent to the heated metal surface via the access port so as to at least loosen the combustion deposit, the cleaning agent comprising an ammonium-free non-effervescent solution of sodium bicarbonate, and a wetting agent for the solution; and (c) permitting the loosened combustion deposit to exhaust from the boiler via an exhaust flue.
The heated metal surface from which the sulphide combustion deposit is to be removed is typically of a thermally resistant metal such as is conventionally employed in domestic boilers.
The method according to the invention results in loosening of the sulphide combustion deposit on the metal surface before it is exhausted through the exhaust flue. Optionally, the loosened deposit may be removed from the surface mechanically, prior to exhausting in gas phase through the flue, together with exhaust combustion gases arising in the boiler.
The cleaning agent comprising the solution of the sodium bicarbonate and the wetting agent is preferably made up immediately before use, because protracted storage of an aqueous solution of sodium bicarbonate results in deterioration and degradation of the sodium bicarbonate.
In one embodiment of the invention, the cleaning agent may contain a zirconium salt, such as a zirconium carbonate, in a catalytic amount (an amount to catalyse breakdown of sulphide combustion deposits).
Preferably, the cleaning agent used in the method according to the invention contains no further active cleaning ingredients, which results in the advantage that the cleaning agent need only employ economically produced bulk ingredients. These ingredients are preferably of food grade such that there are no inherently harmful chemicals used, and the ingredients are safe to transport and use.
The cleaning agent may contain additional non-deleterious ingredients; an example of such an ingredient is a dye or pigment (which is preferably intimately mixed with sodium bicarbonate powder before the latter is dissolved in water to produce the cleaning agent used in the method according to the invention). Such a dye or pigment, which is preferably of food grade, offers the advantage that it is easier for the user to identify the cleaning agent before or after mixing with the detergent.
The cleaning agent is preferably applied to the heated metal surface in the form of droplets (especially atomised droplets) by spraying, typically by the use of manually operable spraying apparatus. Such spraying apparatus should be under relatively low pressure, so as to avoid impacting the deposit with the spray.
As indicated above, the solution used according to the invention is typically made up immediately before use; the solution should be mixed rapidly and used promptly, and not exposed to temperatures in excess of 50°C before application to the heated surface(s). Such rapid mixing and use is generally only suitable for professional use.
It is particularly preferred that the method according to the invention be carried out in a maintenance cycle, preferably when at least part of a domestic oil-fired pressure jet boiler has been removed to permit access and maintenance. Such a maintenance cycle preferably includes an inspection step before and/or after application of the cleaning agent. It is preferred to mechanically remove large and/or loose deposits from the surfaces to be cleaned, before application of the cleaning agent according to the invention.
The method according to the invention provides the further advantage that the sodium bicarbonate present in the cleaning agent results in at least partial neutralization of the acidic environment present in the boiler, thereby helping to combat corrosion caused by acid gases.
It is preferred that the cleaning agent used in the method according to the invention contains from 5 to 15 grams of sodium bicarbonate per litre of water and/or 1 to 5 grams of food-grade detergent as wetting agent. The detergent is preferably supplied in the form of an aqueous concentrate, to be diluted with water prior to use.
Examples of suitable food-grade detergents include anionic and non-ionic surfactants.
It is particularly preferred that the major surface active ingredient of the detergent (in proportions by weight) is an anionic surfactant, such as fatty acid soap, or an alkylsuiphonic acid salt.
Such an anionic surfactant is typically present in aqueous solution in a concentration of 5 to 25% by weight (prior to mixing with the sodium bicarbonate solution).
The detergent may also contain a relatively minor amount of one or more non-ionic surfactants, such as carboxymethyl cellulose, a starch or a polyethoxylatecl wetting agent. Such a non-ionic surfactant is typically present in aqueous solution in a concentration of up to 10% (such as up to 5%) by weight (prior to mixing with the sodium bicarbonate solution). The detergent is preferably substantially free of cationic surfactants, but may contain relatively minor amounts of aniphoteric surfactants.
The sodium bicarbonate may be provided in solid form (typically in the form of powder) for solution in water (and mixing with detergent) prior to use; such solid sodium bicarbonate is preferably dyed or pigmented as described above.
The present invention therefore comprises a pack for use in a method according to the invention, the pack comprising a first container containing solid (such as powdered) sodium bicarbonate, optionally a dye or pigment as described above, and optionally a zirconium salt, and a second container containing aqueous wetting agent. The contents of the first container are to be dissolved in water and mixed with the contents of the second container immediately prior to use in the method according to the invention.
The present invention further extends to the combination of sodium bicarbonate, a dye or pigment for the sodium bicarbonate, and optionally a zirconium salt, and a wetting agent, for use in forming an aqueous solution for removal of combustion products from heated metal surfaces in domestic oil-fired pressure jet boilers (including condensing boilers).
The present invention will now be illustrated in the following examples, in which reference is made to the accompanying drawings.
Example I
This example illustrates schematically the removal of deposit from a conventionally flued domestic oil fired pressure jet boiler; reference is made to.Figure 1 of the accompanying drawings which illustrates schematically how the process according to the invention can be put into operation.
grams of dyed powdered sodium bicarbonate and 15 ml of ammonium-free liquid detergent concentrate were dissolved in 2.5 litres of cold or warm water. The resulting solution was charged into a standard garden pressure sprayer 1 A conventionally flued domestic oil fired pressure jet boiler 2 is first prepared for cleaning. The door cover 3 is removed and then the baffles 4 are removed. Any loose deposits within the boiler 2 are removed by vacuuming or the like.
The door cover 3 is then loosely replaced and the burner 5 fired on domestic hot water mode for about 5 to 7 minutes until the flue 6 is hot. The door cover 3 is then again removed and with the burner still firing, solution from sprayer 1 is economically sprayed into the boiler 2 until deposits within the boiler have been satisfactorily removed. The service of the boiler should then be completed as normal, and the baffles 4 and door 2 replaced before the boiler is put back into service.
The solution from sprayer 1 should be sprayed as soon as practicable after the solution has been made up.
Example 2
This example illustrates schematically the removal of deposit from a balanced flue domestic oil fired boiler; reference is made to Figures 2 and 3 of the accompanying drawings which illustrate schematically how the process according to the invention can be put into operation.
grams of dyed powdered sodium bicarbonate and 15 ml of ammonium-free liquid detergent concentrate were dissolved in 2.5 litres of cold or warm water. The resulting cleaning solution was charged into a standard garden pressure sprayer 1.
As flue products will always spill from low level or balanced flues (see Figs 2 and 3), the boiler 11 is heated to 55 to 70°C with the flue cover in place, but with baffles 13 removed. The flue cover 12 is then removed and the solution sprayed from sprayer I as described above with reference to Figure 1. The flue cover is then replaced and the burner again fired. Further cleaning solution is sprayed from sprayer 1.
The service of the boiler should then be completed as normal, and the baffles 13 and flue cover replaced before the boiler is put back into service.
Claims (5)
- Claims 1 A method of removing sulphide combustion deposit from at least one heated metal surface located in the interior of a boiler, which metal surface in use is exposed to and heated by combustion gases and is in communication with an exhaust flue, which method comprises: (a) opening a port in said boiler to permit access to said heated metal surface in the interior of the boiler, (b) directing a spray of non- acidic cleaning agent to said heated metal surface via the access port so as to at least loosen said combustion deposit, the cleaning agent comprising an ammonium-free non-effervescent solution of sodium bicarbonate, and a wetting agent for the solution; and (c) permitting said loosened.combustion deposit to exhaust from said boiler via said exhaust flue.
- 2 A method according to claim 1, wherein baffles are taken out from the interior of the boiler prior to step (b).
- 3 A method according to claim I or 2, wherein the cleaning agent is produced by dissolving sodium bicarbonate in water and then mixing the solution with the wetting agent immediately before step (b).
- 4 A method according to any of claims I to 3, further comprising at least partial mechanical removal of said combustion deposit from the heated metal surface after step (b).
- 5. A method according to any of claims 1 to 4, wherein the cleaning agent further comprises at least one zirconium salt.6 A method according to any of claims 1 to 5, wherein the cleaning agent contains no further active cleaning ingredients.7 A method according to any of claims 1 to 6, wherein the cleaning agent contains a dye or pigment.8 A pack for use in a method according to any of claims 1 to 7, the pack comprising a first container containing solid sodium bicarbonate and optionally a dye or pigment therefor and/or a zirconium salt, and being ammonium-free, and a second container containing aqueous wetting agent and being substantially acid free.9 In combination, sodium bicarbonate, a dye or pigment for said sodium bicarbonate, an aqueous wetting agent, and optionally a zirconium salt, for use in forming an aqueous solution for removal of suiphide combustion products from heated metal surfaces of domestic oil-fired pressure jet boilers.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GBGB0711315.2A GB0711315D0 (en) | 2007-06-13 | 2007-06-13 | Removal of combustion deposits |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB0810744D0 GB0810744D0 (en) | 2008-07-16 |
| GB2451163A true GB2451163A (en) | 2009-01-21 |
| GB2451163B GB2451163B (en) | 2010-01-06 |
Family
ID=38331950
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GBGB0711315.2A Ceased GB0711315D0 (en) | 2007-06-13 | 2007-06-13 | Removal of combustion deposits |
| GB0810744A Expired - Fee Related GB2451163B (en) | 2007-06-13 | 2008-06-12 | Removal of combustion deposits |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GBGB0711315.2A Ceased GB0711315D0 (en) | 2007-06-13 | 2007-06-13 | Removal of combustion deposits |
Country Status (2)
| Country | Link |
|---|---|
| GB (2) | GB0711315D0 (en) |
| IE (1) | IES20080483A2 (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1523491A (en) * | 1976-11-23 | 1978-09-06 | Colgate Palmolive Co | Methods and compositions for cleaning ovens and the like |
| US4144185A (en) * | 1978-02-24 | 1979-03-13 | The United States Of America As Represented By The Secretary Of The Interior | Method and composition for removing calcium sulfate scale deposits from surfaces |
| US5834411A (en) * | 1994-09-23 | 1998-11-10 | Church & Dwight Co., Inc | General purpose aqueous cleaner |
| EP1873452A1 (en) * | 2005-08-09 | 2008-01-02 | Asahi Glass Company, Limited | Method for removal of acidic adherent matter |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6583103B1 (en) * | 2002-08-09 | 2003-06-24 | S.C. Johnson & Son, Inc. | Two part cleaning formula resulting in an effervescent liquid |
-
2007
- 2007-06-13 GB GBGB0711315.2A patent/GB0711315D0/en not_active Ceased
-
2008
- 2008-06-12 GB GB0810744A patent/GB2451163B/en not_active Expired - Fee Related
- 2008-06-12 IE IE20080483A patent/IES20080483A2/en not_active IP Right Cessation
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1523491A (en) * | 1976-11-23 | 1978-09-06 | Colgate Palmolive Co | Methods and compositions for cleaning ovens and the like |
| US4144185A (en) * | 1978-02-24 | 1979-03-13 | The United States Of America As Represented By The Secretary Of The Interior | Method and composition for removing calcium sulfate scale deposits from surfaces |
| US5834411A (en) * | 1994-09-23 | 1998-11-10 | Church & Dwight Co., Inc | General purpose aqueous cleaner |
| EP1873452A1 (en) * | 2005-08-09 | 2008-01-02 | Asahi Glass Company, Limited | Method for removal of acidic adherent matter |
Also Published As
| Publication number | Publication date |
|---|---|
| GB0810744D0 (en) | 2008-07-16 |
| GB2451163B (en) | 2010-01-06 |
| IES20080483A2 (en) | 2009-03-18 |
| GB0711315D0 (en) | 2007-07-25 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20170612 |