GB2389169A - Electric flow boiler - Google Patents
Electric flow boiler Download PDFInfo
- Publication number
- GB2389169A GB2389169A GB0212296A GB0212296A GB2389169A GB 2389169 A GB2389169 A GB 2389169A GB 0212296 A GB0212296 A GB 0212296A GB 0212296 A GB0212296 A GB 0212296A GB 2389169 A GB2389169 A GB 2389169A
- Authority
- GB
- United Kingdom
- Prior art keywords
- electric flow
- inlet
- outlet
- boiler
- passages
- 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.)
- Withdrawn
Links
- 238000010438 heat treatment Methods 0.000 claims abstract description 53
- 239000012530 fluid Substances 0.000 claims abstract description 10
- 230000007935 neutral effect Effects 0.000 claims abstract description 5
- 238000004891 communication Methods 0.000 claims description 8
- 229910052751 metal Inorganic materials 0.000 claims description 3
- 239000002184 metal Substances 0.000 claims description 3
- 239000007788 liquid Substances 0.000 abstract description 18
- 239000000463 material Substances 0.000 description 17
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 13
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 239000004677 Nylon Substances 0.000 description 4
- 238000005485 electric heating Methods 0.000 description 4
- 238000007654 immersion Methods 0.000 description 4
- 229920001778 nylon Polymers 0.000 description 4
- 230000007797 corrosion Effects 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 3
- 238000005868 electrolysis reaction Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- 230000001681 protective effect Effects 0.000 description 3
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 229920003023 plastic Polymers 0.000 description 2
- 239000004800 polyvinyl chloride Substances 0.000 description 2
- 229920000915 polyvinyl chloride Polymers 0.000 description 2
- 238000005086 pumping Methods 0.000 description 2
- 229910001369 Brass Inorganic materials 0.000 description 1
- 229920002302 Nylon 6,6 Polymers 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 239000010951 brass Substances 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 231100001261 hazardous Toxicity 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910001092 metal group alloy Inorganic materials 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 210000002445 nipple Anatomy 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/10—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor
-
- 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
- F24H1/00—Water heaters, e.g. boilers, continuous-flow heaters or water-storage heaters
- F24H1/10—Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium
- F24H1/101—Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium using electric energy supply
- F24H1/102—Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium using electric energy supply with resistance
- F24H1/103—Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium using electric energy supply with resistance with bare resistances in direct contact with the fluid
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B3/00—Ohmic-resistance heating
- H05B3/40—Heating elements having the shape of rods or tubes
- H05B3/42—Heating elements having the shape of rods or tubes non-flexible
- H05B3/44—Heating elements having the shape of rods or tubes non-flexible heating conductor arranged within rods or tubes of insulating material
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B2203/00—Aspects relating to Ohmic resistive heating covered by group H05B3/00
- H05B2203/021—Heaters specially adapted for heating liquids
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)
- Instantaneous Water Boilers, Portable Hot-Water Supply Apparatuses, And Control Of Portable Hot-Water Supply Apparatuses (AREA)
Abstract
An electric flow boiler (10) comprising an electrically insulating body (12) defining means (14) for ducting liquid between an inlet (22) and an outlet (24) and at least two elongate electrically uninsulated heating elements (20) disposed in the duct means (14) for heating fluid flowing through the duct means (14) between the inlet (22) and the outlet (24) when the boiler (10) is in use, wherein the heating elements are arranged such that neutral connections are provided adjacent the inlet and the outlet.
Description
(-, 2389169
Electric Flow Boiler The invention relates to an electric flow boiler and to a central heating system comprising an electric flow boiler.
Electric flow boilers have conventionally comprised an immersion heater element disposed in a flow path for water to heat the water. A conventional immersion heater element Is formed by an electrical heating element disposed within a protective sheath with an electrically insulating layer therebetween. The sheath protects the element from harsh conditions, maintains its shape and contains and minimises damage should the element bum out. The electrically insulating layer keeps the element positioned correctly and prevents the element from contacting the sheath which is usually earthed.
A problem with conventional immersion heater elements is that the electrically insulating layer also acts as a thennally insulating layer which opposes the efficient transfer of heat from the electrical heating element to the protective sheath and consequently from the sheath to the liquid.
The bulk of the multilayered structure of a conventional immersion heater is not conducive to the provision of a compact electric flow boiler.
To alleviate these disadvantages, GB 2 340 590 A teaches use of an electrically uninsulated electric heating element in an electric flow boiler. The electric flow boiler comprises an electrically insulating body having a duct for ducting liquid between an inlet and an outlet and an elongate electrically uninsulated electric heating element disposed in the duct for heating the liquid in the duct when the boiler is in use.
( 2 GB 2 340 590 A also teaches an embodiment wherein the electrically insulating body comprises a block having a plurality of passages extending between opposite ends thereof, a first passage being in Row communication with the inlet, and a second passage being in flow communication with the outlet, the passages being interconnected to define the duct. Adjacent passages may be substantially parallel and interconnected to define the duct by further passages extending transversely thereto. Whilst the teaching of GB 2 340 590 A provides for a more compact boiler and improves the efficiency of heat transfer from the heating element to the liquid to be heated, it suffers from a number of potential drawbacks.
During passage of the liquid through the duct, leakage current from the heating element may pass mto the liquid, having hazardous consequences. This may be particularly problematical where metal pipes are used, as is commonly the case in conventional heating systems. Furthermore, a heating element failure may produce a prospective fault path via the heating media.
Also, due to the close proximity of one heating element to another' where a plurality of passages are provided, electrolysis between the elements may occur, thereby causing corrosion of the elements. The potential for this will be most prevalent in the area around the ends of the passages where the connecting transverse passages are situated because there is no part of the electrically insulating body between adjacent heating elements in this region. A solution to this problem would be to sheath or insulate this section of the element but this solution has an adverse effect on the transfer of heat to the fluid for the reasons aforementioned, which also affects the compactness of the arrangement.
In order to alleviate these disadvantages, the invention, broadly stated, employs at least two electrically uninsulated electric heating elements in an electric flow boiler, such that the ends of the heating elements adjacent the inlet and outlet of an electrically insulated body of the boiler are at a substantially neutral voltage (i.e. O V). Thus, according to a first aspect of the present invention, there is provided an electric flow boiler comprising an electrically insulating body defining means for ducting a fluid between an inlet and an outlet and at least two elongate electrically uninsulated heating elements disposed in the duct means for heating fluid flowing through the duct means between the inlet and the outlet when the boiler is in use, wherein the heating elements are arranged such that neutral connections therefor are provided adjacent the inlet and the outlet.
Preferably, the two or more heating elements are arranged in series.
Preferably, adjacent ends of the heating elements are arranged to have substantially equipotential voltages when the boiler is in use. This reduces electrolysis between adjacent elements which can cause corrosion.
The electrically insulating body may comprise an axially extending elongate member having an axial passage extending therethrough, a portion of the passage intermediate opposite ends thereof defining the duct means. The member may be cylindrical or cuboid, for ease of manufacture and installation, although other forms will be readily contemplated by the man skilled in the art. Preferably' the passage is substantially cylindrical.
Alternatively, the electrically insulating body may comprise a block having at least two passages, extending between opposite ends thereof, a first of the
passages being in fluid communication with the inlet, and a second of the passages being in fluid communication with the outlet, the passages being interconnected to define the duct means. More preferably, adjacent passages are substantially parallel in a first direction and are interconnected by a further passage extending transversely thereto. This arrangement is beneficial in that it improves the compactness of the boiler. Preferably, for ease of manufacture and efficient heat transfer, the passages are cylindrical.
Preferably, the inlet andJor outlet are earthed for further improved safety.
The inlet and/or outlet may be coupled to earthed metal pipes.
The electrically insulating body may be thermally insulating, is preferably made of a plastics material and more preferably made of a nylon material.
Preferably, the electric heating element comprises an elongate metallic wire which may be made of an alloy comprising nickel, chromium and iron. The wire may be configured into a helical coil, in which case preferably, the length of the coil is 2.5 to 3 times its closed coil length which may be less than 60 mm. The outer diameter of the coil may be less than 10 mm. The outer diameter of the wire may be less than I mm.
The inlet and outlet of the duct means are preferably provided with respective pipe cormections for connecting the inlet and outlet to respective pipes, and the pipe connections may be formed from a material having substantially the same coefficient of thermal expansion as the electrically insulating body. For example, if the electrically insulating body is made from a nylon material, the pipe connection means may be made from a polyvinylchloride material.
/ 5 According to a second aspect of the present invention, there is provided a central heating system comprising at least one electric flow boiler according to the first aspect of the invention.
Preferably, the system includes a closed flow circuit including the duct means, at least one radiator and a pump for pumping water around the circuit. The system may comprise a flow switch for switching off an electrical supply to the electric flow boiler when flow around the circuit falls below a predetermined rate.
The system may comprise a water temperature control thermostat for controlling the temperature of the water in the circuit. The system may include an electrical supply control thermostat for switching off said electrical supply when the temperature of the water in said flow circuit exceeds a predetermined temperature.
In order that the invention may be well understood, some embodiments thereof, which are given by way of example only will now be described with reference to the accompanying drawings, in which: Figure I is a cross-sectional view of an electric flow boiler; Figure 2 is a perspective view of the electric flow boiler shown in Figure Figure 3 is a schematical view of a central heating system comprising two of the electric flow boilers as shown in Figures 1 and 2.
Referring to Figure 1, the electric flow boiler shown generally at I O comprises an electrically insulating body 12 having duct means 14 for ducting liquid between an inlet 22 and an outlet 24 therefor and four elongate electrically uninsulated electrical heating elements 20 disposed in the duct means 14 for
l 6 contacting liquid being ducted between the inlet 22 and the outlet 24 when the boiler 10 is in use.
As shown in Figures I and 2, the electrically insulating body 12 comprises a block having a plurality of passages 27,28,29,30 extending between opposite ends thereof, a first passage 27 being in flow communication with the inlet 22, and a second passage 30 being in flow communication with the outlet 24, the plural passages being interconnected to define the duct means 54. Adjacent passages are substantially parallel in a first direction and are interconnected to define the duct means by a further passage extending transversely thereto. As shown in Figure 1, there are three transverse passages 32,33,34 extending between the first passage 27 and a third passage 28, between the third passage 28 and a fourth passage 29 and between the second passage 30 and the fourth passage 29, respectively.
The insulating body 12 is formed generally of a block having six rectangular faces, opposite faces of which are parallel.
An inlet aperture 40 is provided in a face 44 of the block 12, as viewed from the right of the block 12 shown in Figures 1 and 2. The inlet aperture 40 is at a longitudinal end portion of the face 44. The inlet passage extends from the inlet aperture 40 and opens into the first passage 27. An outlet aperture 42 is provided in a face 46 opposite to face 44 and is at a longitudinal end portion of face 46. The outlet passage extends from the outlet aperture 42 and opens into the second passage 30. Each passage 27,28,29,30 extends the entire longitudinal length of the insulating body 12 and at respective longitudinal end portions thereof, each passage is threaded for receiving a respective correspondingly threaded bolt 38.
The inlet passage and the outlet passage are each threaded at respective radially outward portions thereof for engagement with respective pipe connections.
The insulating body is preferably thermally insulating and it has been found that a plastics material is a particularly suitable material from which to make the insulating body 12. In general though the material chosen should have a high melting point which is at least higher than the boiling point of water, a high continuous service temperature, low thermal conductivity and be self-extinguishing.
It has been found that a particular suitable material is nylon and more specifically nylon-66 which is inexpensive and easily machinable.
The electrically uninsulated electrical heating elements 20 comprise an elongate metallic wire. It has been found that a metal alloy comprising nickel, chromium and iron is a particularly suitable material from which to malce the heating elements 20. Other materials may be used, though, provided they satisfy the electrical and thermal requirements of the heating elements.
The wire is configured into a helical coil by winding the wire under tension onto a former. It has been found that a suitable diameter for the former is 6 mm and a suitable diameter for the wire is less than I mm. Once the tension is released, the diameter of the coil is allowed to expand and it has been found that the outer diameter of the coil after expansion is preferably less than 10 mm and more preferably about 8 mm. The closed coil length of the coil is preferably less than 60 mm. The coil is then stretched and it is been found that the coil should preferably be stretched to 2.5 to 3 times its closed coil length. A heating element 20 constructed as described above with a length of 2.66 m and a resistance of 24 ohms, produces a power of 2.41;W at a potential difference of 240V.
( 8 One end of the thus formed heating element 20 is soldered into the slot of a nickel plated brass pan head screw 16. The pan head screw is mounted through a bore of a bolt 38 and secured thereto with a nut 18 with a washer (not shown) therebetween. This assembly is mounted to the insulating body 12 by inserting the heating element 20 into and along each of the axial passages 27,28,29,30 and threading the bolt 38 into the correspondingly threaded end portion of the axial passages 27,28,29,30. The free end of the heating element 20 is then extended to project out of the open end of the axial passage 26. Preferably, the elastic limit of the coil is not exceeded. The free end of the heating element 20 is then soldered into the slot of a second pan head screw 16 and mounted through the bore of a second bolt 38 and secured thereto with a second nut 18 with a second washer (not shown) therebetween. The second bolt 38 is mounted to the free end portion of the axial passages 27,28,29,30 by threading the bolt 38 with the correspondingly threaded end portion of the axial passages 27,28,29,30. Since one end of the coil is already fixed relative to the insulating body 12, when the second bolt 38 is threaded into the axial passage 27,28,29,30, it will deform the coil by causing one end thereof to rotate relative to the other end thereof. To compensate this deformation, the wire is pre-
rotated in a counter direction before mounting the second bolt 38 to the axial passages 27,28,29,30.
Each pan head screw 16 protrudes outwardly of the respective nut 18 forming a respective electrical connection device at each end of said elongate heating element 20 whereby a potential difference can be applied across the heating element.
Potential differences are applied such that neutral connections are terminated about the inlet 22 and the outlet 24. Live terminations are made at the
1 9 furthest points from the inlet 22 and outlet 24 for the heating elements 20 in passages 27 and 30, respectively. In a preferred embodiment, the potential differences between adjacent portions of elements 20 either side of the transverse passages 32,33,34 are substantially zero to eliminate any potential electrolysis or corrosion caused by the close proximity of opposing poles. It will be clear to one skilled in the art that the invention could be adapted to enable use of two or more heater elements in series in a single passage with electrical connections provided therealong, in order to effect this embodiment of the invention.
A liquid tight seal is formed at each end of the axial passage when the respective bolts 38 are mounted as hereinbefore described. Therefore, liquid entering the insulating body 12 through the inlet aperture 40 passes down the inlet passage, through the duct 14, down the outlet passage and leaves the insulating body through the outlet aperture 42, as indicated by the arrows shown in Figure I. The inlet and the outlet are provided with pipe connections for connecting the inlet and the outlet to respective pipes. In the illustrated embodiment, the pipe connections are hexagon nipples 36. The pipe connections are preferably formed from a material having substantially the same coefficient of thermal expansion as the electrically insulating body because otherwise it has been found that the connections have a tendency to leak liquid when cooling of the insulating body 12 and pipe connection occurs and contraction takes place. If the insulating body is made of nylon then it has been found that a suitable material for the pipe connections is polyvinylchloride. In use, liquid is caused to contact the electrically uninsulated electrical heating elements 20 which are heated by applying a potential difference across
1Q respective pan head screws at each end of the heating elements. The liquid is pumped into the insulating body through the inlet 22 and into the duct 14 which ducts the water over the heating elements 20. The liquid leaves the insulating body through the outlet 24. Since the heating elements 20 are in contact with the liquid they are heating, a high efficiency of heat transfer is achieved which in turn results in reduced running costs of the boiler. Furthermore, as the heating element 20 is formed of a helical wire coil only and not also a protective sheath and insulating layer, a more compact size may be achieved for the boiler.
Preferably, the size of the block is about 50 non x 180 now x 100 mm.
A respective electrically uninsulated electrical heating element 20 is disposed in a respective one of the passages 27,28,29,30. In this embodiment, four heating elements 20 are disposed in the insulating body positioned successively along the duct means 14. In other words, liquid entering the insulating body through inlet aperture 40 passes first down the inlet passage and then into the duct means 14 which ducts the liquid successively along first passage 27, transverse passage 32, third passage 28, transverse passage 33, fourth passage 29, transverse passage 34, second passage 30 and into the outlet passage and out of the insulating body 12 through the outlet aperture 42. Therefore, the heating capacity of 4 heating elements is available within one insulating body contributing to compactness.
The block of the insulating body 12 may be fabricated from a solid block of material. The three previously mentioned passageways 27,28,29,30 are bored through the block. Also, at least two passageways 48, SO are bored transversely to the passageways 27,28,29,30. These two passageways each extend completely through the bloc}; from the left face 46 to the right face 44 as shown in Figure I and
form the transverse passageways 32,33,34 and the inlet and the outlet passages.
Following boring, the portions of the passageways shown in the dashed lines are filled or blocked off thereby completing the duct means 14. The passageways may be filled by any suitable filling material but preferably the material is the same or similar material to that from which the remainder of the block is fabricated.
Alternatively, the passageways may be blocked by inserting a plurality of worm screws or the like therein to desired positions along the passageway. It will be understood that the filling or blocking procedure avoids the production of hot spots in the duct means during use of the boiler.
It will be clear to one skilled in the art that the number of passages andlor heating elements may be varied depending on the particular heating requirements.
Furthermore, connections for pipes adjacent the inlet and/or outlet may be earthed for improved safety, as may be any pipes where the pipes are electrical conductors. Referring to Figure 3, a heating system shown generally at 100 comprises at least one electric flow boiler 102 as shown in Figure 1. The system 100 includes a closed flow circuit 104 including the duct means of the boiler, at least one radiator 106 and a pump 108 for pumping water around the circuit 104. The system 100 further comprises a flow switch 110 for switching off an electrical supply (not shown) to the electric flow boiler 102 when flow around the flow circuit 104 falls below a predetermined rate, for example 4.5 litreiminute. The system 100 further comprises a water temperature control thermostat 1 12 for controlling the temperature of the water in the flow circuit 104. The system 100 further comprises an electric supply control thermostat 1 14 for switching off the electrical supply when the
! 12 temperature of the water in the flow circuit 104 exceeds a predetermined temperature. The electrical supply control thermostat 1 14 may also turn off the electrical supply if the water temperature control thermostat 1 12 fails.
As shown specifically in Figure 3, the system 100 comprises two electric flow boilers 102 but more or less may be provided as required. If more than one is provided, the electric flow boilers 102 should preferably be connected in series in the circuit 104. The remaining components of the circuit 104 should preferably be connected in series.
The thermostats 1 12 and 1 14, the electric flow boilers and the flow switch are provided as a unit in a case 1 16 which may be fixed in a convenient place in the property to be heated. The pump 108 is usually provided outside the case 116 but may if desirable be provided in the case 1 16. Only one radiator 106 is shown specifically in Figure 4 but usually at least one radiator 106 is provided in each room of the property to be heated.
Claims (10)
1. An electric flow boiler comprising an electrically insulating body defining means for ducting a fluid between an inlet and an outlet and at least two elongate electrically uninsulated heating elements disposed in the duct means for heating fluid flowing through the duct means between the inlet and the outlet when the boiler is in use, wherein the heating elements are arranged such that neutral connections therefor are provided adjacent the inlet and the outlet.
2. An electric flow boiler as claimed in claim 1, wherein the two or more heating elements are arranged in series.
3. An electric flow boiler as claimed in claim 2, wherein adjacent ends of the heating elements are arranged to have substantially equipotential voltages when the boiler is in use.
4. An electric flow boiler as claimed in any preceding claim, wherein the electrically insulating body comprises an axially extending elongate member having an axial passage extending therethrough, a portion of the passage intermediate opposite ends thereof defining the duct means.
5. An electric flow boiler as claimed in any one of claims I to 3, wherein the electrically insulating body comprises a block having at least two passages extending between opposite ends thereof, a first of the passages being in fluid
( 14 communication with the inlet, and a second of the passages being in fluid communication with the outlet, said passages being interconnected to define said duct means.
6. An electric flow boiler as claimed in claim 5, wherein adjacent ones of the passages are substantially parallel in a first direction and are interconnected to define the duct means by a further passage extending transversely thereto.
7. An electric flow boiler as claimed in any preceding claim, wherein the inlet and/or outlet are earthed.
8. An electric flow boiler as claimed in any preceding claim, wherein the inlet and/or outlet are coupled to earthed metal pipes.
9. An electric flow boiler substantially as hereinbefore described with reference to Figure 1 of the drawings.
10. A central heating system comprising an electric flow boiler as claimed in any preceding claim.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0212296A GB2389169A (en) | 2002-05-28 | 2002-05-28 | Electric flow boiler |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0212296A GB2389169A (en) | 2002-05-28 | 2002-05-28 | Electric flow boiler |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB0212296D0 GB0212296D0 (en) | 2002-07-10 |
| GB2389169A true GB2389169A (en) | 2003-12-03 |
Family
ID=9937583
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0212296A Withdrawn GB2389169A (en) | 2002-05-28 | 2002-05-28 | Electric flow boiler |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2389169A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB991408A (en) * | 1960-11-25 | 1965-05-05 | Leonard Henry Vickers | Improvements in or relating to electric water heaters |
| US3230346A (en) * | 1960-09-09 | 1966-01-18 | Eckerfeld | Electric continuous flow heater having a plurality of heating channels |
| GB2243064A (en) * | 1990-04-10 | 1991-10-16 | Electricity Council | An ohmic heater |
| GB2268671A (en) * | 1992-07-10 | 1994-01-12 | Electricity Ass Tech | Internal resistance ohmic heating apparatus for fluids |
| GB2340590A (en) * | 1998-08-14 | 2000-02-23 | Rosecharm Limited | Electric flow boiler |
-
2002
- 2002-05-28 GB GB0212296A patent/GB2389169A/en not_active Withdrawn
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3230346A (en) * | 1960-09-09 | 1966-01-18 | Eckerfeld | Electric continuous flow heater having a plurality of heating channels |
| GB991408A (en) * | 1960-11-25 | 1965-05-05 | Leonard Henry Vickers | Improvements in or relating to electric water heaters |
| GB2243064A (en) * | 1990-04-10 | 1991-10-16 | Electricity Council | An ohmic heater |
| GB2268671A (en) * | 1992-07-10 | 1994-01-12 | Electricity Ass Tech | Internal resistance ohmic heating apparatus for fluids |
| GB2340590A (en) * | 1998-08-14 | 2000-02-23 | Rosecharm Limited | Electric flow boiler |
Also Published As
| Publication number | Publication date |
|---|---|
| GB0212296D0 (en) | 2002-07-10 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |