FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
An efficient heating appliance
APPLICANTS:
Crompton Greaves Limited, CG House, Dr Annie Besant Road, Worli, Mumbai 400-030, Maharashtra, India, an Indian Company.
INVENTORS:
D'Melo Dawid; of Crompton Greaves Ltd, AMPTC, Global R&D Centre, Kanjurmarg (East), Mumbai - 400042, Maharashtra, India; Sarma Budhavarapu Pavan Srinivas and Garg Damodar; both of Crompton Greaves Ltd, Reliability Centre, Global R&D Centre, Kanjurmarg (East), Mumbai - 400042, Maharashtra, India; and Upadhyay Pankaj; of Crompton Greaves Ltd, Industrial Design Centre (IDC), Global R&D Centre, Kanjurmarg (East), Mumbai - 400042, Maharashtra, India; all Indian Nationals.
PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the nature of this invention and the manner in which it is to be performed.

FIELD OF THE INVENTION:
This invention relates to the field of heating appliances.
Particularly, this invention relates to a liquid heating appliance with improved heating efficiency and reduced scaling.
More particularly, this invention relates to a water heating appliance with improved heating efficiency and reduced scaling.
BACKGROUND OF THE INVENTION:
Water heating is a thermodynamic process using an energy source to heat water above its initial temperature. Typical domestic uses of hot water are for cooking, cleaning, bathing, and space heating.
Appliances for providing a more-or-less constant supply of hot water are variously known as water heaters, hot water heaters, hot water tanks, boilers, heat exchangers, calorifiers, or geysers depending on whether they are heating potable or non-potable water, in domestic or industrial use and their energy source.
A heating element converts electricity into heat through the process of Joule heating. Electric current through the heating element encounters resistance, resulting in heating of the element.
The heating element is one of the most important features in electrical heaters. These heating elements are generally made of metal and get hot from electrical resistance. These heating elements range in power consumption from 2kW to 4kW in domestic units, and up to 72kW for industrial units.

Electrical heaters for liquids have been around for a long time. In the known art, the heating element is usually made up of metal. However, salt and other impurities present in water, come in contact with the heating element, resulting in scale formation.
Water heaters are meant to work with water of varying hardness. Hardness in water is quantified by the amount of calcium and magnesium ions present in water. Most of these salts show decreasing solubility with an increase in the solution temperature, leading to their precipitation in the form of the crystals which is known as scaling. Scaling on the heating element of the water heater occurs due to the deposition of insoluble calcium and magnesium carbonates, silicates and other insoluble salts on the heating element of the water heater.
Manufactures of elements consider a nominal thickness of scale greater than 1/16 inch as excessive. Excessive scale build-up reduces the efficiency of the geyser since the scale has a lower thermal conductivity. This results in the water taking a longer time to heat as the scaling increases. Although normally the problem of scaling is found in hard water areas, but softened water can also cause scaling. The scale tends to act as an insulator around the element. Heat is no longer being transferred to the water at the proper rate, A build-up of heat in the element occurs, exceeding the operating temperatures of the element, resulting in element failure.
Various solutions have been proposed to prevent or inhibit the deposition of scales on heating element of the water heaters.

The Chinese Patent CN2712034 discloses the use of a Teflon coating on a metal substrate for the purpose of providing an anti-corrosive coating as well as a coating which will prevent the formation of scale. However, the disadvantage of a pure Teflon coating on the heating element is that it is a bad conductor of heat. This would lower the efficiency of the heating element.
Spargers are devices used to achieve optimum circulation of water stored in a tank. Its application is generally reserved for installations where space around a tank is restricted. Incoming water is forced to travel to the tank's inaccessible regions. Thus it provides maximum circulation and prevention of areas of stagnation. The Sparger pipe requires appropriate stayed support from the tank base or edge, torn prevent sag and undue strain being transmitted to the tank structure.
OBJECTS OF THE INVENTION:
An object of the invention is to provide an efficient heating appliance wherein the heating element of the appliance is coated with the composition comprising teflon or teflon and nano-particles.
An object of the invention is to provide an efficient heating appliance wherein the heating element of the appliance is coated with the composition comprising teflon or teflon and nano-particles and having a sparger for creation of turbulence placed in close proximity to a heating element.
Another object of the invention is to provide an efficient heating appliance wherein it substantially eliminates the scale deposition and scale build-up on the heating element of the appliance.

Yet another object of the invention is to provide an efficient heating appliance wherein it improves the heating efficiency of the heating element and thus the efficiency of appliance.
An object of the invention is to provide an efficient heating appliance wherein the heating element becomes corrosion resistant.
Yet another object of the invention is to provide an efficient heating appliance wherein the sparger prevents areas of stagnation around the heating element by creating turbulence.
Still another object of the invention is to provide an efficient heating appliance which is efficient, safe and cost effective.
Still another object of the invention is to provide an efficient heating appliance where it reduces maintenance of the heating appliances and increases the life of the heating element.
SUMMARY OF THE INVENTION:
According to the invention there is provided an efficient heating
appliance;
The appliance comprises a heating tank assembly, base plate fitted with a
heating element and inlet, and outlet pipe;
said assembly including a tank assembly adapted to serves as the
insulated casing and the general body for said water heater assembly, said
body with a pre-calculated capacity and further allowing it to encompass
suitably positioned base plate fitted with the heating element and inlet;

said heating elements coated with the composition comprising teflon and
nano-particles;
said inlet has a sparger pipe which is held in close proximity to said
heating element thereby causing turbulence in close proximity to said
heating element in said heating zone.
Typically, said heating element is coated with scale deposition preventing material layer,
Typically, said scale deposition preventing material layer comprises of Teflon (PTFE).
Preferably, said scale deposition preventing material layer comprising Teflon (PTFE) contains nano-alumina.
Preferably, the said sparger and the said heating element are held in close proximity.
More preferably, the said sparger and said heating element are held in close proximity either co-axial and co-centric or parallel on the base plate.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
The invention will now be described in relation to the accompanying drawings, in which:

Figure 1 illustrates a perspective view of the base plate fitted with the tubular heating element and inlet has sparger pipe which is placed in parallel and closely to the said heating element.
Figure 2 illustrates a perspective view of the base plate fitted with the spiral heating element and inlet has sparger pipe which is co-axial and co-centric to the said heating element.
Figure 3 illustrates comparative graphic representation of scale deposition on heating element of appliance.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
In liquid heating appliances, the heating element is used to increase the water temperature. Salt and other impurities in water come in contact with the heating element, thus leading to scale formation. Scaling and corrosion lead to inefficient heating. This deteriorates the performance and increases the maintenance of the heating appliance.
In order to eliminate such deterioration, the heating element should be protected from scaling.
According to one of the embodiment of the invention, there is provided the efficient heating appliance, the said heating element of the appliances is coated with composition comprising Teflon, thereby preventing scale formation on the surface of the heating element.
According to one of the embodiment of the invention, there is provided the efficient heating appliance, the said heating element of the appliances

is coated with composition comprising Teflon and nano-particles, thereby preventing scale formation on the surface of the heating element.
According to one of the embodiment of the invention, there is provided the efficient heating appliance, the said heating element of the appliances is place in close proximity with an inlet sparger pipe.
In one of the embodiments, the spiral heating element is co-axial and co-centric to the said inlet sparger pipe.
In one of the embodiments, the tubular heating element is placed in parallel and closely to the said inlet sparger pipe.
Figure 1 illustrates a perspective view of the base plate fitted with the tubular heating element and inlet has sparger pipe which is placed in parallel and closely to said heating element.
The sparger (1) is placed adjacent to the tubular heating element (2). The heating element (2) and the sparger (1) are positioned parallel to each other. The water gushes through the perforations (3) in the sparger (1) and comes in contact with the heating element (2). This action inhibits corrosion and scale deposition by restricting settlement of rust, salts and other corrosive elements on the heating element (2). The sparger (1) and the heating element (2) are preferably connected to a base plate (4) perpendicularly.
The base plate (4) includes inlet for entry of water into the sparger (1). The water enters the sparger (1) through the water inlet (5) situated at the lower region of the base plate (4). The sparger (1) and the heating

element (2) are located on one end of the planar surface of the base plate (4), whereas the water inlet (5) is located at the opposite end of the planar surface of the base plate (4). Water enters through the inlet (5) and flows via the sparger (1). It effuses through the perforations (3) and comes in contact with the heating element (2).
Figure 2 illustrates a perspective view of the base plate fitted with the spiral heating element and inlet has sparger pipe which is co-axial and co-centric to the said heating element. The said heating element (2) is spiral shaped. The spiral heating element (2) encloses the sparger (1). The heating element (2) is in close contact with sparger (1). The water gushes through the perforations (3) in the sparger (1) and comes in contact with the heating element (2). This action inhibits corrosion and scale deposition by restricting settlement of rust, salts and other corrosive elements on the heating element (2). The base plate (4) includes inlet for entry of water into the sparger (1). The water enters the sparger (1) through the water inlet (5) situated at the lower region of the base plate (4). The sparger (1) and the heating element (2) are located on one end of the planar surface of the base plate (4), whereas the water inlet (5) is located at the opposite end of the planar surface of the base plate (4). The water enters through the inlet (5) and flows via the sparger (1). It effuses through the perforations (3) and comes in contact with the heating element (2).
The said heating element is coated with the composition comprising Teflon.
In yet another embodiment of this invention, the heating element (2) is coated with composition comprising Teflon and nano particles.

Particularly, the nano-particles in the said coating composition are selected from but not limited to alumina, silica, aluminium nitride, boron nitride, silicon carbide and the like.
More particularly, the nano-particles in the said coating are of alumina.
More particularly, the nano-particles used in the said coating are in the range of 0.01 to 10.0%.
The coating on the surface of the heating element is done using conventional methods such as dipping, spraying, plasma vapor deposition, preceded by conventional surface preparation techniques such as grease removal, sandblasting and the like.
The addition of nano-particles in Teflon is done by dispersing the powders in the Teflon formulation under a combination or stand alone method of ultrasonication and high speed dispersion. Other conventional methods can be used to disperse the nano-particles in the Teflon formulation by those knowledgeable in the art.
The heating appliance is water heater appliance for providing a more-or-less constant supply of hot water is variably known as water heater, hot water heater, hot water tank, boiler, heat exchanger, calorifier, or geyser depending on whether it is heating potable or non-potable water, in domestic or industrial use and its energy source.
The coating helps in the inhibition of scale deposition and scale build-up on the heating element and also leads to improvement in the heating efficiency of the heating element. Further, the sparger that is placed in

close proximity with the heating element, creates turbulence near the heating element and prevents areas of stagnation on the element, thereby inhibiting corrosion as well as substantially eliminating scale deposition and scale build-up on the heating element.
According to the invention, the scale deposition has been reduced by 25-35% as compared to that without a sparger. The reduction in the scale deposition will allow for increased heating efficiency, since the thermal insulating property of scaling is reduced.
The following experimental examples are illustrative of the invention but not limitative of the scope thereof:
EXAMPLE:
The external surface of spiral heating element (A) is coated with composition comprising only Teflon. The external surface of spiral heating element (B) is coated with composition comprising only Teflon and nano-particles of alumina. The external surface of tubular heating element (C) is coated with composition comprising only Teflon. The external surface of tubular heating element (D) is coated with composition comprising only Teflon and nano-particles of alumina. The spiral heating element (E) is uncoated. The tubular heating element (F) is uncoated. All the six elements are used in the separate geyser and placed in close proximity with the sparger. The scale deposition and heating efficiency of all six geysers are compared and listed in Table 1.
Table 1 illustrates the comparison of results with respect to the heating efficiency and scale deposition between the conventional uncoated

heating element, heating element with Teflon coating and scale-inhibiting heating element of the invention
Table 1

Sr no Heating element type Scale deposition (g) in time (hrs)

Ohrs 6 hrs 12 hrs 18 hrs 24 hrs
1 Spiral heating element coated with Teflon containing 0.5% alumina without sparger 0 4.58 8.5 14.34 21.42
2 Spiral heating element coated with Teflon containing 0.5% alumina with sparger 0 3.01 6.24 10.08 14.15
3
.. . Reduction in scale deposition with application of sparger (%) 0.00 34.28 26.59 29.71 33.94
According to result obtained in Table 1, the scale deposition has been reduced when heating element is coated with coating composition comprising Teflon and nano alumina is used along with sparger as compared to that of heating element coated with coating composition comprising Teflon and nano alumina without a sparger. The reduction in the scale deposition results into increased heating efficiency, since the thermal insulating property of scaling is reduced-
Figure 3 illustrates comparative graphic representation of reduction in scale deposition with and without use of sparger along with use of heating

element coated with composition comprising Teflon and nano-particles of alumina. According to Figure 3, it is evident that if we use sparger along with use of heating element coated with the composition comprising Teflon and nano particle, scale deposition is reduced as compared to use of heating element coated with the composition comprising Teflon and nano particle without use of sparger.
In the present invention as described above, it is to be understood that this invention is not limited to particular methodologies and materials described, as these may vary as per the person skilled in the art. It is also to be understood that the terminology used in the description is for the purpose of describing the particular embodiments only, and is not intended to limit the scope of the invention.

We claim,
1. An efficient heating appliance;
the appliance comprises a heating tank assembly, base plate fitted
with a heating element and inlet, and outlet pipe;
said assembly including a tank assembly adapted to serve as the
insulated casing and the general body for said water heater
assembly, said body with a pre-calculated capacity and further
allowing it to encompass suitably positioned base plate fitted with
the heating element and inlet;
said heating elements coated with the composition comprising
teflon and nano-particles;
said inlet has a sparger pipe which is held in close proximity to said
heating element thereby causing turbulence in close proximity to
said heating element in said heating zone.
2. The efficient heating appliance as claimed in claim 1, wherein the nano-particles used in the said coating are selected from but not limited to alumina, boron nitride, silicon carbide and the like.
3. The efficient heating appliance as claimed in claim 1, wherein the nano-particles used in the said coating are of alumina.
4. The efficient heating appliance as claimed in claim 1, wherein the nano-particles used in the said coating are in the range of 0.01 to
5.0%.

5. The efficient heating appliance as claimed in claim 1, wherein said sparger is held in close proximity either co-axial and co-centric or parallel to the said heating element on the base plate.
6. The efficient heating appliances as claimed in any of the preceding claims, wherein the scale deposition or scale build-up is substantially eliminated.
7. The efficient heating appliances as claimed in any of the preceding claims, wherein the heating efficiency of the appliance is substantially increased.