WO2016046750A1

WO2016046750A1 - Burner

Info

Publication number: WO2016046750A1
Application number: PCT/IB2015/057303
Authority: WO
Inventors: Gian Luca FALLETI
Original assignee: Nanoprom Chemicals S.R.L.
Priority date: 2014-09-22
Filing date: 2015-09-22
Publication date: 2016-03-31

Abstract

Burner (1) having at least one treated surface adapted to come into contact with the fuel and/or the oxidiser and provided with an outer layer, which is particularly smooth and with a surface tension such as to allow the humidity to flow away.

Description

BURNER'

TECHNICAL FIELD

The present invention concerns a burner, a burner component, a method for the treatment of a burner and a method for the treatment of a burner component.

BACKGROUND OF THE INVENTION

In the field of burners the need to increase efficiency, reduce consumption and reduce maintenance operations is increasingly felt.

In particular, the burners currently available, although offering increasingly high performance and despite the fact that increasingly sophisticated materials are used, easily become dirty and damaged (in particular, by abrasion and deposit of soot and/or non-combusted particulate) and do not always have optimal efficiency.

The object of the present invention is to provide a burner, a burner component, a method for the treatment of a burner and a method for the treatment of a burner component, which at least partially solve the drawbacks of the known art and are, at the same time, easy and inexpensive to produce and/or use.

SUMMARY

According to the present invention, a burner, a burner component, a method for the treatment of a burner and a method for the treatment of a burner component are provided as claimed in the following independent claims and, preferably, in any one of the claims depending directly or indirectly on the independent claims.

BRIEF DESCRIPTION OF THE FIGURES

The invention is described below with reference to the attached figures, which illustrate some non-limiting embodiment examples thereof, in which:

- figure 1 is a perspective view of a burner according to the present invention;

- figure 2 is a perspective view in an enlarged scale of a detail of the burner of figure 1 ;

- figure 3 is a photograph of an element of a burner head, half of which is treated according to the present invention; figure 4 illustrates equipment used to test a burner according to the present invention; and

- figure 5 is an electron microscope photograph of a cross section of a surface of the burner of figure 1.

DETAILED DISCLOSURE

According to a first aspect of the present invention, a burner is provided having at least one treated surface adapted to come into contact with the fuel and/or the oxidiser and provided with an outer layer.

It has been experimentally observed that the characteristics of the outer layer according to the present invention have led to an elongation of the flame and a more uniform outflow, reducing the "flickering" of the flame. Therefore, the treatment performed provides (by cleaning the airflows) a taller-burning flame, thus allowing a reduction in fuel consumption with consequent reduction in the non-combusted part which causes pollution, or exploitation of an elongation of the flame, without an increase in the pressure of the air- gas mixture. Furthermore, some tests performed have highlighted that the parts treated are only minimally subject to the corrosive aggression due to the continuous flow of particulate present in the air and in the gas.

In particular, the outer layer (which in practice comes into contact with the fuel and/or the oxidiser) has a low surface tension so as to allow the humidity to flow away. Advantageously, the outer layer has a very low roughness. According to some specific embodiments, the outer layer has a contact angle with water at 60°C which is higher than 110°, in particular up to 125°.

The measurements of the contact angle are performed with reference to the UNI EN 15802:2004 method.

According to alternative embodiments, the measurements of the contact angle are performed with reference to the AST D5725 standard, in particular using the Kruss DSA30 instrument.

Advantageously, the outer layer has a surface tension greater than 15 N/m, in particular greater than 17 N/m. The measurements are performed according to the UNI EN 15802:2004 method with UNI EN 828 extension.

More precisely, the outer layer has a surface tension lower than 23 N/m, in particular lower than 22 N/m.

According to some embodiments, the outer layer has a roughness (Ra) lower than 0.12μπι. The measurements are performed according to the UNI EN (ISO) 4287: (UNI EN (ISO) 4287:1997 or UNI EN (ISO) 4287:2009) method, in particular using the Alpa SM RT 25 roughness tester.

Advantageously, the outer layer comprises (in particular, contains mainly) silicon oxide (S1O₂) · In some cases, the outer layer also comprises particles of nanometric size adapted to provide greater mechanical stability and to raise the temperature.

According to some embodiments, the outer layer has a thickness from 0.5μπι to 20μπι. Advantageously, the outer layer is resistant (i.e. it does not burn or dissolve) at least up to a temperature of 1100°C. In particular, with reference to the non-limiting embodiment of figures 1 and 2, the burner, which is indicated by the reference number 1 and comprises a body 2, a duct 3 and a head 4 which, in turn, is provided with a diffuser 5 (for the passage of the oxidiser - in particular, air) and a nozzle 6 (for outflow of the fuel - for example methane) . The burner 1 can also contain an air pre-heating chamber.

Advantageously, the treated surface (and therefore the outer layer) is arranged in the area of at least one between the body 2, the duct 3, the diffuser 5 and the head nozzle 6 (and air pre-heating chamber) . In some cases, the burner 1 has a plurality of treated surfaces (and therefore outer layers) arranged in the area of the body 2, the duct 3, the diffuser 5 and the nozzle 6 (and air pre-heating chamber) .

According to a second aspect of the present invention, a component is provided for a burner (according to the first aspect of the present invention) . The component has said surface provided with the outer layer. In particular, the component is chosen from the group consisting of: a body, a duct, a head diffuser, a head nozzle (and an air pre-heating chamber) .

According to a third aspect of the present invention, a method is provided for the treatment of a base burner. The method involves applying on a surface a layer of an active product, which hardens (in particular, vitrifies) due to the humidity present in the air so as to create an outer layer on the surface and therefore obtain a treated surface.

Advantageously, the hardening takes place in the presence of oxygen (in particular, in air) .

More precisely, the active product hardens by means of a cross-linking sol-gel process (due to the humidity present in the air) .

Advantageously, the hardening takes place at ambient temperature (in particular, via a process lasting approximately 7 days) . In some cases, the hardening takes place at temperatures from 100°C to 150°C (for example approximately 130°C) for reduced times (for example approximately 30-50 minutes; more precisely, approximately 40 minutes) .

Advantageously, the hardening takes place at atmospheric pressure .

Note that, indeed, it is not necessary for the hardening to take place before use of the burner. The hardening can also take place during the first use due to the temperatures reached by the burner. In this regard, it is observed that the characteristics of the active product are such that the surface is dust-dry after less than 50 seconds (in particular, approximately 45 seconds) .

According to some embodiments, the outer layer and the treated surface are defined (independently of each other) according to the above indications relative to the first aspect of the present invention. In particular, the burner as defined according to the first aspect of the present invention is obtained by means of the method.

Advantageously, the burner as per the first aspect of the present invention can be obtained (or, more precisely, is obtained) with the method according to the third aspect of the present invention.

According to a fourth aspect of the present invention, a method is provided for the treatment of a burner component to obtain the component as per the second aspect of the present invention .

The method involves applying on a surface a layer of an active product which hardens (in particular, vitrifies) due to the humidity present in the air so as to create an outer layer on the surface and therefore obtain a treated surface.

Advantageously, the hardening takes place at ambient temperature (in particular, via a process lasting approximately 7 days) . In some cases, the hardening takes place at temperatures ranging from 100°C to 150°C (for example approximately 130°C) for reduced times (for example approximately 30-50 minutes; more precisely, approximately 40 minutes) .

Advantageously, the hardening takes place at atmospheric pressure .

In particular (for all aspects of the invention), for the active product, all products consisting of methyl phenyl silicone resins which, according to the formulation, provide specific performances in terms of flow-away of the water vapour which forms in the equipment and optimal protection against corrosion of the treated parts, should be considered suitable as coating for the purpose in question.

All products formulated with silicones, the siliceous groups of which increase resistance to temperature, including adducts of components such as molybdenum disulphide and epoxy phenols with high resistance to temperature, are also suitable.

In particular, protective coating products are preferred with temperature resistance of no less than 650°C; in particular no less than 800°C; and specifically no less than 1200°C.

In the specific case of this application, said protective coating is an inorganic system having silicon groups according to Si-O-NH-Si bonds.

A system with a totally inorganic matrix should be preferred to a mixed organic/inorganic system.

In particular the protective coating (outer layer) is an adduct of nano-components which, binding with the 0 groups, increase the characteristics of resistance to temperature, in addition to the elasticity performances which the system must maintain vis-a-vis the thermal expansion to which it is subject. The nano-components should be considered as modification elements of the formulation system. All the nanoparticles with dimensions (smaller than) lOOnm are permitted in the system. In particular nanoparticles of (smaller than) 80nm are recommended. Specifically, nano- dispersions in solvent at (below) 50nm are more tolerable. Silica nano-dispersions are particularly recommended. More specifically, a nano-carbon dispersion (of approximately 50nm) is recommended.

The addition of carbon nanotubes could give the coating a dark colouring. In this case the colouring of the coating is not an element considered.

A carrier with solvent base forms an integral part of said system. All ketone solvents are acceptable, specifically MEK and similar. According to some embodiments, the outer layer and the treated surface are defined (independently of each other) according to the above indications relative to the first aspect of the present invention.

Advantageously, the burner as per the second aspect of the present invention can be obtained (or, more precisely, is obtained) with the method according to the fourth aspect of the present invention.

Further characteristics of the present invention will become clear from the following description of a merely illustrative and non-limiting example.

Example 1

This example reports the procedure for the treatment of a burner .

The burner was disassembled and all its parts (in particular body, burner, head, diffuser, nozzle, tube for pre-heating the air where present, air inlet chamber and all the parts in contact with air and/or with gas) were sprayed both internally and externally using a pneumatic sprayer (e.g. pressure mixed air spraying gun) provided with a nozzle of approximately 1 mm, at a pressure of 2 bars, with the product Biflow (containing a silicon compound which reacts with the air so as to obtain silicon oxide) marketed by the company Nanoprom Chemicals S.R.L. so as to obtain a coating layer of approximately 0.05-20μπι. The pieces are dust-dry after 45 seconds and are immediately ready for use.

Figure 5 is an electron microscope photograph of a cross section of a surface of the burner thus treated and shows excellent adhesion of the fine layer of Biflow (identified by the number 11) to the silica substrate (identified by the number 12 ) .

Example 2

This example describes comparison tests between some burners obtained following the procedure described in example 1 with respect to analogous non-treated burners.

These tests were performed using the ATEQ BAIE instrument (pressure 20mbar scale end 500L/h) according to the procedure described in its operating manual using the following parameters: test circuit seal test according to EC gas regulation: pressure 150m/bar, loss limit fixed for this experiment lOcc/h, maximum limit permitted lOOcc/h; flow rate test performed at stabilised pressure and at machine flow rate limit: pressure 18-19m/bar, flow rate 558-5611/h; maximum actual flow rate of burner being tested 50m³/h, equal to 50,000 1/h.

Figure 3 illustrates the equipment used for the tests performed. In particular: the number 7 indicates a flow rate nozzle, D2mm, max possible for the threshold of the system available at the time; 8 indicates a Venturi valve for opening the flow; 3 indicates a duct of the burner; 2 indicates a cast aluminium body of the burner, subject of the tests; 9 indicates a hot-wire anemometer; 10 indicates a probe of the anemometer in a fixed position.

The following table 1 shows the data recorded at equal variables .

Table 1

Test Air Stabilised flow Temperat Outlet flow

pressure rate ure

1 19.2 m/bar 560.9 1/h 18.65°C 0.54-0.59 m/s

2 19.1 m/bar 558.8 1/h 19.87°C 0.59-0.63 m/s

3 19.1 m/bar 559.7 1/h 19.77°C 0.59-0.66 m/s The test 1 is relative to a burner with cast aluminium body.

Tests 2 and 3 are relative to two different burners, both with body made of cast aluminium treated according to example 1. Two different burners were used to demonstrate the reproducibility of the results obtained.

As can be noted, in tests 2 and 3 outlet flows were obtained significantly and unexpectedly higher than those obtained in test 1. In this way a considerable increase in efficiency of the burners of the present invention is clearly demonstrated.

Example 3

The procedure of example 2 was repeated using an ATEQ D520 (pressure 20mbar scale end 10,0001/h) instead of the ATEQ BAIE .

The data recorded are reported in the following tables 2 (tests at lOm/bar) and 3 (tests at 20m/bar) .

Table 2

Test 4 is relative to a burner with cast aluminium body.

Tests 5, 6 and 7 are relative to two different burners with cast aluminium body treated according to example 1 with Biflow coating of ΙΟμπι, 15μπι and 20μπι, respectively.

Table 3

Test Air Stabilised flow Temperat Outlet flow pressure rate ure

8 20.2 m/bar 10050 1/h 20°C 1.02-1.10 m/s

9 20 m/bar 10130 1/h 20.75°C 1.07-1.13 m/s

10 20.1 m/bar 10130 1/h 20.44°C 1.06-1.11 m/s

11 20 m/bar 10300 1/h 20.2°C 1.07-1.17 m/s

Test 8 is relative to a burner with cast aluminium body.

Tests 9, 10 and 11 are relative to two different burners with body made of cast aluminium treated according to example 1 with Biflow coating of ΙΟμπι, 15μπι and 20μπι, respectively.

Observing the outlet flow values, it can be seen that the treated burners have greater stabilisation of the upward flow.

The flow rate values indicate a greater " flowability" of the outlet flow.

Example 4

Different burners were tested, produced by different manufacturers and treated as described in example 2. Compared to the non-treated burners, the treated burners highlighted an elongation of the flame up to 10cm, and a more uniform outflow, with less flickering. Therefore, the treatment performed results in (by cleaning the air flows) a taller- burning flame, thus allowing a reduction in fuel consumption or exploitation of elongation of the flame, without an increase in the pressure of the air-gas mixture. Furthermore, tests performed in some plants highlighted that the treated parts are only minimally subject to the corrosive aggression due to the continuous flow of particulate present in the air.

To better detect these results, only half a diffuser was treated and then used. After a brief period of use (2 months) the diffuser was photographed. The photograph obtained is the one illustrated in figure 3, showing the non-treated part in the top left portion and the treated part in the bottom right portion .

The improved cleaning reduces the blockages in the flow passages over time due to the accumulation of combustion residues. In this way more uniform and constant flows are obtained in the long term.

Claims

1. - A burner having at least one treated surface, which is adapted to come into contact with the fuel and/or the oxidizer and is provided with an outer layer, which has a contact angle with water at 60°C that is greater than 110°, in particular up to 125°.

2. - A burner according to claim 1, wherein said outer layer has a surface tension that is greater than 15 N/m, in particular greater than 17 N/m.

3. - A burner according to claim 1 or 2, wherein said outer layer has a surface tension that is lower than 23 N/m, in particular lower than 22 N/m.

4. - A burner according to claim 1 or 2, wherein said outer layer has a roughness (Ra) lower than 0.12μπι.

5. - A burner according to any of the preceding claims, wherein the outer layer has a thickness ranging from 0.5μπι to 20μπι and comprises (in particular, mainly contains) silicon oxide.

6. - A burner according to any one of the preceding claims and comprising a body, a duct, a head diffuser, a head nozzle; said treated surface being arranged in the area of at least one among the body, the duct, the head diffuser and the head nozzle .

7. - A burner according to claim 6 and having a plurality of treated surfaces, which are arranged in the area of the body, the duct, the head diffuser and the head nozzle.

8. - A burner according to any of the preceding claims, wherein said outer layer is resistant at least to a temperature up to 1100° .

9. - A component for a burner according to any one of the preceding claims; the component has said surface provided with the outer layer; in particular, the component being chosen in the group consisting of: a body, a duct, a head diffuser, a head nozzle.

10. - A method of treatment of a base burner to obtain the burner according to any of the claims from 1 to 8; the method involves applying, onto a surface, a layer of an active product, which hardens (in particular, vitrifies) thanks to the humidity present in the air, so as to create the outer layer on the surface and, thus, obtain the treated surface.

11. - A method according to claim 10, wherein the active product comprises a silicon compound, which reacts with air so as to obtain silicon oxide (S1O2) ·

12. - A method according to claim 11 or 12, wherein the hardening takes place at ambient temperature, in particular at atmospheric pressure.

13. - A burner according to any one of the claims from 1 to 8, which can be obtained with a method according to one of the claims from 10 to 12.

14. - A method of treatment of a component for a burner to obtain the component according to claim 9; the method involves applying, onto a surface, a layer of an active product, which hardens (in particular, vitrifies) thanks to the humidity present in the air, so as to create the outer layer on the surface and, thus, obtain the treated surface.

15. - A method according to claim 14, wherein the hardening takes place at ambient temperature, in particular at atmospheric pressure.