GB2499719A - Method of manufacturing a condensate discharge pipe of a condensing boiler - Google Patents
Method of manufacturing a condensate discharge pipe of a condensing boiler Download PDFInfo
- Publication number
- GB2499719A GB2499719A GB1302478.1A GB201302478A GB2499719A GB 2499719 A GB2499719 A GB 2499719A GB 201302478 A GB201302478 A GB 201302478A GB 2499719 A GB2499719 A GB 2499719A
- Authority
- GB
- United Kingdom
- Prior art keywords
- pipe
- discharge pipe
- coating
- condensate discharge
- manufacturing
- 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
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- 238000004519 manufacturing process Methods 0.000 title claims abstract description 27
- 238000000576 coating method Methods 0.000 claims abstract description 118
- 239000011248 coating agent Substances 0.000 claims abstract description 105
- 239000000463 material Substances 0.000 claims abstract description 56
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 37
- 230000002209 hydrophobic effect Effects 0.000 claims abstract description 24
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 23
- 239000005871 repellent Substances 0.000 claims abstract description 22
- 230000002940 repellent Effects 0.000 claims abstract description 21
- 230000003075 superhydrophobic effect Effects 0.000 claims abstract description 18
- 238000007710 freezing Methods 0.000 claims abstract description 17
- 230000008014 freezing Effects 0.000 claims abstract description 16
- 238000000034 method Methods 0.000 claims abstract description 13
- 238000007598 dipping method Methods 0.000 claims abstract description 11
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 11
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 6
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims abstract description 5
- 239000002041 carbon nanotube Substances 0.000 claims abstract description 5
- 229910021393 carbon nanotube Inorganic materials 0.000 claims abstract description 5
- 238000005507 spraying Methods 0.000 claims abstract description 4
- 229920000642 polymer Polymers 0.000 claims description 10
- 239000004800 polyvinyl chloride Substances 0.000 claims description 9
- 229920000915 polyvinyl chloride Polymers 0.000 claims description 9
- -1 polyethylene Polymers 0.000 claims description 8
- 239000002105 nanoparticle Substances 0.000 claims description 7
- 239000004698 Polyethylene Substances 0.000 claims description 5
- 229920003023 plastic Polymers 0.000 claims description 5
- 239000004033 plastic Substances 0.000 claims description 5
- 229920003229 poly(methyl methacrylate) Polymers 0.000 claims description 5
- 229920000573 polyethylene Polymers 0.000 claims description 5
- 239000004926 polymethyl methacrylate Substances 0.000 claims description 5
- 239000002356 single layer Substances 0.000 claims description 5
- 229920000193 polymethacrylate Polymers 0.000 claims description 4
- 239000004743 Polypropylene Substances 0.000 claims description 2
- 229920001155 polypropylene Polymers 0.000 claims description 2
- 230000002265 prevention Effects 0.000 claims description 2
- 230000008569 process Effects 0.000 abstract description 6
- 238000011176 pooling Methods 0.000 abstract description 2
- 239000011852 carbon nanoparticle Substances 0.000 abstract 1
- 239000007788 liquid Substances 0.000 description 8
- 239000010410 layer Substances 0.000 description 7
- 239000002699 waste material Substances 0.000 description 7
- 238000010438 heat treatment Methods 0.000 description 6
- 239000000758 substrate Substances 0.000 description 6
- 238000003618 dip coating Methods 0.000 description 5
- 238000009434 installation Methods 0.000 description 5
- 239000007787 solid Substances 0.000 description 4
- 239000002351 wastewater Substances 0.000 description 4
- 239000002114 nanocomposite Substances 0.000 description 3
- NIPNSKYNPDTRPC-UHFFFAOYSA-N N-[2-oxo-2-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(CNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 NIPNSKYNPDTRPC-UHFFFAOYSA-N 0.000 description 2
- 235000019000 fluorine Nutrition 0.000 description 2
- 125000001153 fluoro group Chemical group F* 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 229920000867 polyelectrolyte Polymers 0.000 description 2
- 238000009736 wetting Methods 0.000 description 2
- JPVQCHVLFHXNKB-UHFFFAOYSA-N 1,2,3,4,5,6-hexamethyldisiline Chemical compound CC1=C(C)[Si](C)=[Si](C)C(C)=C1C JPVQCHVLFHXNKB-UHFFFAOYSA-N 0.000 description 1
- 229920002518 Polyallylamine hydrochloride Polymers 0.000 description 1
- 229920002125 Sokalan® Polymers 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 239000000443 aerosol Substances 0.000 description 1
- 150000004703 alkoxides Chemical class 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 239000003546 flue gas Substances 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000002086 nanomaterial Substances 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000004584 polyacrylic acid Substances 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000004528 spin coating Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000002912 waste gas Substances 0.000 description 1
Classifications
-
- 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
- F24H8/00—Fluid heaters characterised by means for extracting latent heat from flue gases by means of condensation
- F24H8/006—Means for removing condensate from the heater
-
- 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
- F24H9/16—Arrangements for water drainage
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
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)
- Application Of Or Painting With Fluid Materials (AREA)
- Rigid Pipes And Flexible Pipes (AREA)
- Laminated Bodies (AREA)
Abstract
The method of manufacturing a condensate discharge pipe 3 of a condensing boiler 1 comprises the steps of: providing a length of pipe; coating at least part of an inner facing surface of the pipe with a hydrophobic coating material; and allowing the coating material to dry. Ideally, the pipe is coated by a super-hydrophobic coating material using a dipping or spraying process. When dipping, the pipe can be lowered vertically into the coating material, removed vertically from the coating material, and maintained vertically until the coating has dried. This allows any excess coating material to drain off of the pipe, thereby preventing pooling of coating material and ensuring a consistent coating thickness. Ideally, the super-hydrophobic coating material comprises either carbon nanotubes or nanoparticles of silica or alumina. A condensate drain pipe of a condensing boiler manufactured using the method of the invention is less likely to freeze in cold ambient conditions. A condensing boiler condensate discharge pipe having an inner-side thereof at least partially coated with a water repellent coating, and a method of preventing freezing of condensate in a condensate discharge pipe are also claimed.
Description
1
Coated Pipe
FIELD OF THE INVENTION
The present invention relates to condensing boilers and problems arising therewith during extreme cold weather. In particular, the present invention provides a solution to problems caused by frozen condensate, by means of a pipe coated with a water repellent material.
BACKGROUND
As part of its commitment to the Kyoto Protocol, in 2005 the UK Government introduced Building Regulations requiring that, unless a more sustainable alternative is available, all new installations of gas & oil powered domestic heating boilers should be of the condensing type. There are estimated to be some 9 million such boilers currently installed in the UK, with new installations continuing at an approximate rate of 1.5 million per year.
Condensing boilers (e.g. as shown in figure 1) work on the principle of reusing heat that would normally be ejected into the atmosphere from the flue of standard efficiency (non-condensing) boilers. The waste gases are passed through a secondary heat exchanger which extracts additional heat by condensing water vapour to liquid water, thus recovering its latent heat. This process increases the efficiency of the boiler by around 12-15 % and at the same time, reduces the temperature of flue gases from approximately 120-180 °C of conventional boilers, to a temperature between 50 °C and 60 °C.
This reduction in temperature causes the water vapour formed during the combustion process to condense. As the droplets of water form, they fall by gravity to collect at the base of the flue manifold. The remaining gases are expelled to the outside environment through a fan-assisted balanced flue. The condensate produced within the appliance is drained into a discharge pipe. Domestic condensing boilers can typically discharge between 1-2 litres of condensate per hour. Often this is piped via the discharge pipe directly from the boiler to external drains.
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Building Regulations and manufacturers installation guidelines stipulate that where possible condensate should be discharged into an internal waste pipe. However, where a boiler is installed on the ground floor the condensate is typically fed into a waste pipe through an external wall of the building and then by an appropriate route to an appropriate drain. Installations on the first or higher floors typically employ a system whereby the condensate is pumped vertically to the discharge pipe into the roof cavity or loft, then through the eaves into a gutter. UK building regulations now stipulate that the pipe cannot be terminated directly into the gutter but must be connected to a vertical downpipe.
In extreme weather, freezing of the condensate during its discharge causes significant problems that can interfere with the functioning of the boiler. Freezing of the pipe or pipes which discharge the condensate leads to blockages and these can have the effect of shutting down the boiler. As a result, users are left unable to work their hot water and/or heating system during the coldest periods of the year. This presents a serious problem, particularly for the elderly and/or infirm, and for families with young children. This freezing often takes place where the discharge pipe passes through an external cavity wall and/or in the loft space, making it particularly difficult to thaw and to prevent from re-freezing.
Such freezing can also cause internal damage to the boiler, necessitating repair/replacement more often than would otherwise be required and increasing the maintenance burden and cost of supplying and insuring condensing boilers.
The present approach to solving this problem is to lag exposed discharge pipes with appropriate material, but this is only partially effective. In addition, it is advisable to incline the condensate-discharge pipe(s) at an angle of greater than or equal to 5°. However, this solution also is not always effective and poor workmanship often means pipes are not angled appropriately.
Alternatively, a trace-heating cable may be applied to the length of the discharge pipe, through which a low current is passed in order to keep its temperature above freezing. This solution has obvious cost implications as it is expensive to install and run, and is wasteful of energy due to the constant heating of the condensate, which is a waste by product of a heating system. Heating waste
3
water to avoid it freezing is not environmentally friendly. Nonetheless, at present this is regarded as the best solution to the problem.
Thus, there is a need for a cheap and effective way to solve the problems caused by freezing of condensate in the discharge pipes of condensing boilers.
The present inventors have now established that when a suitable water repellent coating is applied to the condensate-discharge pipe, this can solve the above problems. Surprisingly, this is so effective that freezing of the condensate can be avoided even when the condensate-discharge pipe is inclined at an angle as low as 1° from the horizontal. The solution is also effective over long lengths of discharge pipe such as when 3 metres or more of the discharge pipe is exposed to potentially freezing conditions.
It is envisaged that coated discharge pipes which prevent freezing can be installed not only on new condensing boilers but also retrofitted to current condensing boilers.
SUMMARY OF THE INVENTION
According to the present invention there is provided a method of manufacturing a condensing boiler condensate discharge pipe, comprising the steps of:
i) providing a length of pipe;
ii) providing a hydrophobic coating material;
iii) coating at least a part of the inside surface of the pipe with the hydrophobic material;
iv) allowing the coating to dry.
Preferably the coating step comprises dipping the pipe into the hydrophobic coating material; or spraying the pipe with the hydrophobic coating material; or both dipping the pipe into the hydrophobic coating material and removing the pipe therefrom vertically.
Advantageously the pipe is of plastics material and more preferably the pipe material is a polymer selected from the group comprising polyethylene,
4
polyvinylchloride or polymethacrylate. The polymer is preferably PVC or poly methyl methacrylate.
The hydrophobic coating material may advantageously comprise a superhydrophobic coating material and the superhydrophobic coating material may comprise nanoparticles of either silica or alumina. Alternatively the superhydrophobic coating material may comprise carbon nanotubes.
Advantageously the step of allowing the coating to dry comprises maintaining the pipe vertically until the coating has dried.
Not forming part of the claimed invention: a condensing boiler system may have a condensate discharge pipe, wherein at least a part of the inside surface of said condensate discharge pipe is coated with a water repellent coating. It will be appreciated that the coating is present on the surface exposed to the water, i.e. at least internally; Or, the use of a pipe, at least a part of the inside surface thereof being coated with a water repellent coating, as a condensate discharge pipe in a condensing boiler system; Or, a method for the prevention of the freezing of condensate in a condensate discharge pipe in a condensing boiler system may comprise coating at least a part of the inside surface of said condensate discharge pipe with a water repellent coating; or a condensate discharge pipe configured to connect to a condensing boiler system at least a part of the inside surface of said pipe having a water repellent coating.
BRIEF DESCRIPTION OF THE FIGURES
Figure 1 is an illustration of a condensing boiler.
DETAILED DESCRIPTION
The coated pipe of the invention is a condensate-discharge pipe which forms part of a condensing boiler system. The other parts of the boiler are conventional and a detailed description thereof is not needed here. Preferably, the condensate
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discharge pipe is suitable for use in or with a standard waste water pipes/gutters/downpipes for domestic and/or commercial use and is compatible therewith in terms of diameter and/or fittings. It will be appreciated that to ensure the continued effectiveness of the pipe to repel water through the entire discharge pipe system, suitably coated joints may also be required.
Preferably, the coated pipe is an integral part of the boiler system. For example it may be connected directly to the condensate reservoir or flue manifold.
Suitable pipes may have a transverse cross-section of essentially cylindrical shape, for example round, oval etc. Most preferably the pipe may be essentially cylindrical, i.e. the cross-section may be substantially circular, although it need not be a perfect circle.
Suitable pipes may have a longitudinal cross-section of essentially any shape. For example, the pipe may be essentially straight, twisted or curved, or a combination of these. As noted in detail below, pipes may also taper.
The coated pipe of the invention may be of essentially any length. The length of the pipe may be limited only by the practicalities of the environment in which the pipe must be installed. The UK building regulations recommend that exposed pipe(s) should be less than 3 metres in length. However, the coated pipe of the current invention is still effective at lengths greater than 3 metres. For example, the coated pipe may be in the range of 0.1 metres to 20 metres, preferably in the range 0.2 to 10 metres, more preferably in the range 0.3 to 3 metres. Typical lengths of the coated pipe can be at least 0.5 m, such as at least 0.75 m especially at least 1 m and so on.
The internal diameter of the coated pipe is preferably in the range of 0.1-20 cm. More preferably the internal diameter is 1-10 cm, especially 1.5 to 4 cm. The dimensions of the coated pipes are preferably of standard size.
The pipe to be coated according to the invention may be formed of any material suitable for coating, for example plastic or metal. Preferably the pipe comprises a plastic material. More preferably this polymer is selected from the group comprising polyethylene, polypropylene, polyvinylchloride and polymethacrylates. Most preferably the pipe comprises PVC, such as uPVC and/or
6
poly methyl methacrylate (PMMA). The skilled man is familiar with the types of material used to form pipes for condensing boilers.
The pipe to be coated typically has a wall thickness in the range of 0.1-5 cm. Preferably the pipe wall thickness is 0.25-3 cm, for example 0.5-2 cm.
The invention primarily relates to the realisation that by coating condensate discharge pipes with a water repellent material, the problem of water freezing within those pipes can be avoided. As the water is repelled by the coated pipe, it simply does not remain in the pipe, and as long as the pipe is angled slightly downwards, the water simply runs away. It will be appreciated that the coating has to be present only inside the pipe. Nevertheless, it may be that for ease of manufacture, both internal and external surfaces of the pipe are coated.
The term water repellent coating means herein a coating which repels water and can be defined by reference to contact angles. The contact angle is used as a quantitative measure of the wetting ability of a particular solid. The contact angle is defined as the angle, S, made by a droplet of liquid on the surface of a solid substrate. If the liquid spreads completely across the surface and forms a film, then, contact angle, 3, is 0°. If there is any degree of beading of the liquid on the surface of the substrate then the substrate is considered to be non-wetting.
The term water repellent is used herein to mean that the contact angle between the coated discharge pipe surface and water is at least 90°, preferably at least 100 °, such as at least 110°, preferably at least 120 °, more especially at least 130 °, most especially at least 140 °.
Coatings with a contact angle of 150° or more are referred to as being "superhydrophobic". These materials are the most preferred for use in the invention.
For example, suitable contact angles would be 160° or more, preferably 165° or more, for example 170° or more. Contact angles are measured using the Static Sessile drop method. The method involves measuring a contact angle goniometre using an optical subsystem to capture the profile of a pure liquid on a solid substrate. The angle formed between the liquid/solid interface and the liquid/vapor interface is the contact angle. Older systems used a microscope optical system with a back light. Current-generation systems employ high resolution cameras and software to capture and analyze the contact angle.
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It will be appreciated that the water repellent coating on the pipe surface should not be washed away by the fluids within the pipe.
Examples of water repellent coating materials are, for example based on the deposition of polyelectrolyte multilayers. That might be accomplished by successive dipping in a substrate such as polyallylamine hydrochloride and polyacrylic acid.
Most preferably the coating material is a superhydrophobic material. Typical superhydrophobic materials are described in US 7485343, the disclosures of which are incorporated here by reference. It is preferred therefore if a superhydrophobic coating is achieved using a precursor sol comprising a metal alkoxide, a solvent, basic catalyst, fluoroalkyl compound and water. The sol can be deposited on a surface and exposed to hexamethyldisilazine to form a hydrophobic coating. Application of UV to that coating allows the contact angle to be tailored.
US7485343 explains the necessary process.
US 2006/0029808 describes a process for providing a hydrophobic coating on a substrate involving a complex sol dipping process but such coatings could be used here. The hydrophobic coating is based on multilayers of polyelectrolyte.
In particular, superhydrophobic coatings of the invention can be those based on nanoparticles of water repellent elements and salts thereof such as silica and alumina. Coatings might also be based on carbon, e.g. using carbon nanotubes. Essentially, as long as there are no health risks associated with a particular hydrophobic coating material, any such material could be used as a coating herein.
A more recent and highly preferred coating is based on a silica surface, especially a nanoparticulate silica surface. The formed coating preferably takes the form of a silicon dioxide nanostructure. This can be achieved by, for example, dip coating the discharge pipe in a silica solution and evaporating the liquid. More preferably, coating can involve a sol comprising two materials: amorphous silica and a proprietory polymer (of Lotus Leaf Coatings). This sol is available from Lotus Leaf Coatings and is sold as a superhydrophobic coating. Superhydrobic coatings of use in the invention are therefore available commercially from suppliers such as Lotus Leaf Coatings. Careful processing of the material system produces a highly advanced nanocomposite coating. In particular dip coating should take place
8
vertically to present pooling of the sol and the pipe has to be completely dried after dip coating.
Preferably nanoparticles which form the superhydrophobic coating have a diameter in the range 1-500 nm. More preferably the particle diameter is in the range 1-250 nm, e.g. 1-50 nm, 40-100 nm, or 75-150 nm. A preferred coating comprises silica nanoparticles.
Coatings of the invention may have any thickness as long as they are capable of performing the desired function. Thicknesses in the range 0.01-100 |xm are envisaged. Preferably the coating thickness can be in the region of 0.1-50 |im, more preferably 1-10 fim, for example 1-3 |_im.
Suitable coatings may be mono-layer or multi-layer. Multi-layer coatings comprise at least two layers, for example three layers, four layers or five layers.
Each layer may have a thickness in the range 0.1-50 nm, preferably in the range 1-10 |u.m, for example 1-3 (im.
The coating may be applied by any suitable coating operation such as dip-coating, spin coating or aerosol assisted methods such as rod coating, slot coating and other coating methods which are known in the art.
Preferably the coating is applied by a dip-coating process, whereby the target length of pipe is fully immersed in a solution, such as a nano-composite solution. Preferably this solution does not contain substantial amounts of per-fluoro compounds or fluorines. More preferably these compounds are excluded from the solution, i.e. present in an amount less than trace. The pipe may be removed and allowed to dry in ambient conditions.
The most effective coating is achieved by dipping vertically and withdrawing the target pipe vertically, achieving an even "once-only" coating.
The coated pipe formed by the invention is used in combination with a condensing boiler to thus form a condensing boiler system. The term discharge pipe defines the whole or part of the pipe that connects the condensate reservoir to a waste water pipe. It can be the pipe that connects the flue manifold to a waste water pipe, or connects the reservoir to a vertical downpipe attached to the outside of a building and so on.
9
The condensate discharge pipe is most likely to pass through an external wall, such as a cavity wall, to link the condensing boiler to the outside waste pipes. In general, it is at a point within or just outside an external wall that freezing of the condensate becomes a problem. The skilled man can fully appreciate therefore which parts of the condensate discharge pipe need to be coated. It may be for example that in some installations, a first part of the condensate discharge pipe adjacent the boiler does not need to be coated as that part of the pipe remains within the building and is unlikely to freeze. The coating might only be applied therefore to parts of the pipe which are external or parts which are within a cavity wall or loft space and so on.
It is essential however for at least a part of the condensate discharge pipe to be coated according to the invention, e.g. at least 20 % of its length such as at least 40% of its length such as at least 50% of its length, e.g. all of its length.
It will also be appreciated that the discharge pipe may itself be formed from a series of smaller pipes and joints, for example to allow bends to be accommodated. The term condensate discharge pipe is intended to cover the whole or part of the pipe leading from the boiler to the drains and therefore covers pipe units and any joints required to connect pipes together. These joints can be considered to be part of the pipe and will benefit from coating according to the invention.
Provision is made for a joint configured for use with a condensate discharge pipe comprising a coating as hereinbefore defined.
Joints are preferably manufactured so that the inflow pipe will fully enter the joint without butting against a joint wall. Moreover, the outflow pipe will preferably likewise fully enter the joint without butting against a joint wall. This will ensure that there are no points in the joint that will allow water to collect.
Those skilled in the art will appreciate that the condensate discharge pipe may taper at the end so that it fits snugly to the inside wall of a joint or pipe into which it pushes. Joints and pipes are generally provided with male and female adaptations. Hence the male end may be reduced in size to fit inside a standard 32 mm or 19 mm pipe. It may be that only one end of the pipe needs to be tapered, although if manufacturing is easier for both ends to be tapered, then that would not impact on the efficiency of the pipe.
10
The condensing boilers of the invention will preferably have a condensate discharge pipe that is at least in part located externally to the building in which the boiler is installed.
The coated pipe made by the invention remains effective for drainage of waste condensate when inclined at an angle as low as 1°. Preferably the coated pipe of the invention when combined with a condensing boiler is inclined at an angle of at least 1 degree or more downwards, preferably 1.5° or more, more preferably 3° or more, more preferably 5° or more. Angles in the range of 1 to 5° such as 3 to 5° are envisaged. Ideally this inclination occurs for the entire length of the pipe. In particular, the inclination should be present for parts of the pipe that are external, within a cavity wall or within a loft space.
Use of a coated pipe manufactured as hereinbefore described may be used in a condensing boiler system. It is envisaged that this coating technology could be used in general to prevent pipes freezing, especially waste pipes where water is not stored.
The invention also provides for the use of a condensate discharge pipe suitable for use with a condensing boiler system which can be retrofitted to an existing boiler system which does not have the advantageous pipes of this invention.
The invention also provides for the use of a joint suitable for use with a condensate discharge pipe which can be retrofitted to an existing boiler system which does not have the advantageous joints of this invention.
The invention will now be described with reference to the following examples and figure 1.
Example 1
A uPVC pipe was dip coated by full immersion in nano-composite Si solution (containing no per-fluoro compounds or fluorines) available from by Lotus Leaf Coatings as a superhydrobic coating".
The pipe was dipped vertically, removed and allowed to dry completely in ambient conditions.
11
Once fully dry, both the internal and external surfaces of the pipe are rendered water-repellent. It is only the internal surface that needs to be water repellent and the external surface is not important and handling will render the external surface no longer water repellent. The pipe can be installed in a typical condensing boiler system.
Example 2
In Figure 1, condensing boiler (1), has flue manifold (2) connected condensate discharge pipe (3). This pipe passes through external wall (4) to connect to outside waste water pipe (5). Condensate discharge pipe (3) can be provided with a hydrophobic coating as hereinbefore defined.
12
Claims (10)
1. A method of manufacturing a condensing boiler condensate discharge pipe, comprising the steps of:
i) providing a length of pipe;
ii) providing a hydrophobic coating material;
iii) coating at least a part of the inside surface of the pipe with the hydrophobic material;
iv) allowing the coating to dry.
2. A method of manufacturing a condensing boiler condensate discharge pipe according to claim 1, wherein the coating step comprises dipping the pipe into the hydrophobic coating material.
3. A method of manufacturing a condensing boiler condensate discharge pipe according to claim 1, wherein the coating step comprises spraying the pipe with the hydrophobic coating material.
4. A method of manufacturing a condensing boiler condensate discharge pipe according to claim 1, wherein the coating step comprises both dipping the pipe into the hydrophobic coating material and removing the pipe therefrom vertically.
5. A method of manufacturing a condensing boiler condensate discharge pipe according to claim 1, wherein the pipe is of plastics material.
6. A method of manufacturing a condensing boiler condensate discharge pipe according to claim 5, wherein the pipe material is a polymer selected from the group comprising polyethylene, polyvinylchloride or polymethacrylate.
7. A method of manufacturing a condensing boiler condensate discharge pipe according to claim 6, wherein the polymer is PVC or poly methyl methacrylate.
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8. A method of manufacturing a condensing boiler condensate discharge pipe according to any one of claims 1 to 4 wherein the hydrophobic coating material comprises a superhydrophobic coating material.
9. A method of manufacturing a condensing boiler condensate discharge pipe according to claim 8 wherein the superhydrophobic coating material comprises nanoparticles of either silica or alumina.
10. A method of manufacturing a condensing boiler condensate discharge pipe according to claim 8 wherein the superhydrophobic coating material comprises carbon nanotubes.
11 A method of manufacturing a condensing boiler condensate discharge pipe according to any one of the preceding claims, wherein the step of allowing the coating to dry comprises maintaining the pipe vertically until the coating has dried.
10. A method of manufacturing a condensing boiler condensate discharge pipe according to claim 8 wherein the superhydrophobic coating material comprises carbon nanotubes.
11. A method of manufacturing a condensing boiler condensate discharge pipe according to any one of the preceding claims, wherein the step of allowing the coating to dry comprises maintaining the pipe vertically until the coating has dried.
12. A condensing boiler system having a condensate discharge pipe wherein at least a part of the inside surface of said condensate discharge pipe is coated with a water repellent coating.
13. A boiler system as claimed in claim 12, wherein the contact angle of the inside surface of the coated pipe is greater than 120°.
14. A boiler system as claimed in claim 12, wherein the contact angle of the inside surface of the coated pipe is greater than 150°.
15. A boiler system as claimed in any of claims 12 to 14, wherein said pipe comprises a polymer.
16. A boiler system as claimed in any of claims 12-15 wherein said polymer is selected from the group comprising polyethylene, polypropylene and polyvinylchloride.
14
17. A boiler system as claimed in any one of claims 12 to 16, wherein the water repellent coating comprises silica nanoparticles.
18. A boiler system as defined in any of claims 12 to 17, wherein said coated pipe is inclined downwards at an angle of 1 to 5° for at least part of its length.
19. Use of a pipe, at least a part of the inside surface thereof being coated with a water repellent coating, as a condensate discharge pipe in a condensing boiler system.
20. A method for the prevention of the freezing of condensate in a condensate discharge pipe in a condensing boiler system comprising coating at least a part of the inside surface of said condensate discharge pipe with a water repellent coating.
21. A condensate discharge pipe configured to connect to a condensing boiler system at least a part of the inside surface of said pipe having a water repellent coating.
22. A joint configured to connect with a condensate discharge pipe at least a part of the inside surface of said joint having a water repellent coating.
Amendments to the claims have been filed as follows
15
Claims
1. A method of manufacturing a condensing boiler condensate discharge pipe as hereinbefore defined, comprising the steps of:
i) providing a length of pipe;
ii) providing a hydrophobic coating material;
iii) coating at least a part of the inside surface of the pipe with a mono-layer of the hydrophobic material;
iv) allowing the coating to dry.
2. A method of manufacturing a condensing boiler condensate discharge pipe according to claim 1, wherein the mono-layer coating step comprises dipping the pipe into the hydrophobic coating material.
3. A method of manufacturing a condensing boiler condensate discharge pipe according to claim 1, wherein the mono-layer coating step comprises spraying the pipe with the hydrophobic coating material.
4. A method of manufacturing a condensing boiler condensate discharge pipe according to claim 1, wherein the mono-layer coating step comprises both dipping the pipe into the hydrophobic coating material and removing the pipe therefrom vertically.
5. A method of manufacturing a condensing boiler condensate discharge pipe according to claim 1, wherein the pipe is of plastics material.
6. A method of manufacturing a condensing boiler condensate discharge pipe according to claim 5, wherein the pipe material is a polymer selected from the group comprising polyethylene, polyvinylchloride or polymethacrylate.
7. A method of manufacturing a condensing boiler condensate discharge pipe according to claim 6, wherein the polymer is PVC or poly methyl methacrylate.
16
8. A method of manufacturing a condensing boiler condensate discharge pipe according to any one of claims 1 to 4 wherein the hydrophobic coating material comprises a superhydrophobic coating material.
9. A method of manufacturing a condensing boiler condensate discharge pipe according to claim 8 wherein the superhydrophobic coating material comprises nanoparticles of either silica or alumina.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GBGB1110737.2A GB201110737D0 (en) | 2011-06-24 | 2011-06-24 | Coated pipe |
GB1211213.2A GB2492238B (en) | 2011-06-24 | 2012-06-22 | Condensing boiler condensate freezing prevention using hydrophobic-coated drain pipe. |
Publications (3)
Publication Number | Publication Date |
---|---|
GB201302478D0 GB201302478D0 (en) | 2013-03-27 |
GB2499719A true GB2499719A (en) | 2013-08-28 |
GB2499719B GB2499719B (en) | 2014-10-22 |
Family
ID=44485108
Family Applications (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GBGB1110737.2A Ceased GB201110737D0 (en) | 2011-06-24 | 2011-06-24 | Coated pipe |
GB1211213.2A Expired - Fee Related GB2492238B (en) | 2011-06-24 | 2012-06-22 | Condensing boiler condensate freezing prevention using hydrophobic-coated drain pipe. |
GB1302478.1A Expired - Fee Related GB2499719B (en) | 2011-06-24 | 2012-06-22 | Method of manufacturing a condensate discharge pipe having a hydrophobic coating |
Family Applications Before (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GBGB1110737.2A Ceased GB201110737D0 (en) | 2011-06-24 | 2011-06-24 | Coated pipe |
GB1211213.2A Expired - Fee Related GB2492238B (en) | 2011-06-24 | 2012-06-22 | Condensing boiler condensate freezing prevention using hydrophobic-coated drain pipe. |
Country Status (1)
Country | Link |
---|---|
GB (3) | GB201110737D0 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN112833548A (en) * | 2020-12-18 | 2021-05-25 | 青岛经济技术开发区海尔热水器有限公司 | Water heater inner container and water heater with same |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2077452A1 (en) * | 1969-07-25 | 1971-10-29 | Commissariat Energie Atomique | Condenser tubes - with hydrophobic (ptfe) flaps or ribs for increased condensate drainage and heat transfer |
US20060194159A1 (en) * | 2005-02-25 | 2006-08-31 | Sgl Carbon Ag | Block heat exchanger assembly for dust-containing flue gases and method of operating the same |
US20100218831A1 (en) * | 2009-03-02 | 2010-09-02 | Hideaki Yumoto | Drain treatment system |
WO2011057422A1 (en) * | 2009-11-10 | 2011-05-19 | Unilever Plc | Frost free surfaces and method for manufacturing the same |
GB2489425A (en) * | 2011-03-25 | 2012-10-03 | Adey Holdings 2008 Ltd | Preventing freezing in a boiler condensate drain pipe |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH10103846A (en) * | 1996-09-26 | 1998-04-24 | Sanyo Electric Co Ltd | Honeycomb for cold air discharging port and cooled open showcase |
JP2001248951A (en) * | 2000-03-03 | 2001-09-14 | Hitachi Ltd | Refrigerator, and manufacturing method for evaporator for refrigerator chamber for use in former |
US8354160B2 (en) * | 2006-06-23 | 2013-01-15 | 3M Innovative Properties Company | Articles having durable hydrophobic surfaces |
AU2011271108B2 (en) * | 2010-06-24 | 2015-04-16 | Shell Internationale Research Maatschappij B.V. | Pipe transport system with hydrophobic wall |
-
2011
- 2011-06-24 GB GBGB1110737.2A patent/GB201110737D0/en not_active Ceased
-
2012
- 2012-06-22 GB GB1211213.2A patent/GB2492238B/en not_active Expired - Fee Related
- 2012-06-22 GB GB1302478.1A patent/GB2499719B/en not_active Expired - Fee Related
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2077452A1 (en) * | 1969-07-25 | 1971-10-29 | Commissariat Energie Atomique | Condenser tubes - with hydrophobic (ptfe) flaps or ribs for increased condensate drainage and heat transfer |
US20060194159A1 (en) * | 2005-02-25 | 2006-08-31 | Sgl Carbon Ag | Block heat exchanger assembly for dust-containing flue gases and method of operating the same |
US20100218831A1 (en) * | 2009-03-02 | 2010-09-02 | Hideaki Yumoto | Drain treatment system |
WO2011057422A1 (en) * | 2009-11-10 | 2011-05-19 | Unilever Plc | Frost free surfaces and method for manufacturing the same |
GB2489425A (en) * | 2011-03-25 | 2012-10-03 | Adey Holdings 2008 Ltd | Preventing freezing in a boiler condensate drain pipe |
Also Published As
Publication number | Publication date |
---|---|
GB2492238B (en) | 2014-01-01 |
GB2499719B (en) | 2014-10-22 |
GB201110737D0 (en) | 2011-08-10 |
GB201302478D0 (en) | 2013-03-27 |
GB201211213D0 (en) | 2012-08-08 |
GB2492238A (en) | 2012-12-26 |
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Legal Events
Date | Code | Title | Description |
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PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20190622 |