EP3240975B1

EP3240975B1 - Feeding boiler for heating water or other thermal fluid lines with modular heat exchanger and cleaning system

Info

Publication number: EP3240975B1
Application number: EP14830421.5A
Authority: EP
Inventors: Ferreira Braga Lino MANUEL AUGUSTO
Original assignee: Felino-Fundicao De Const Mecanicas SA
Current assignee: Felino-Fundicao De Const Mecanicas SA
Priority date: 2014-12-29
Filing date: 2014-12-29
Publication date: 2018-12-12
Anticipated expiration: 2034-12-29
Also published as: EP3240975A1; WO2016108709A1

Description

Technical Field

This application describes a heating boiler.

Background

It is known from the state of art the existence of heating boilers.
Document US2469253 discloses sectional type boilers that generally comprise a front section and a back section, with any number of middle sections, depending on the dimension and capacity of the boiler, where all sections are made of welded plate. These middle sections are such that hot gases make three longitudinal passes through the boiler. On the contrary, in the now disclosed technology only the heat exchanger of the boiler presents several modules or sections, and the number of passes is directly related with the boiler power, being at least of three vertical passes.
Document US2539669 discloses heat exchangers, and more particularly those used to cool oil and other liquids, whose viscosity grows up when cooled. On the contrary, in the now disclosed technology, the boiler has, as its goal, to heat fluids and not to cool them.
Document US4401155 discloses an heat exchanger built from a plurality of stacked modules, comprising closed channels for the high pressure flow in each module, that extend themselves vertically upward and/or downward from the channels, forming open channels adequate to the low pressure flow when the modules are stacked lengthwise in parallel. This heat exchanger is applied in easy building and cheap manufacturing high pressure procedures. On the contrary, in the now disclosed technology, the heat exchangers comprise individual modules, that are placed adjacent and connected to each other for the passage of a fluid. Gas passes through the heat exchanger modules, where there is a set of cooling fins and not individual channels.
Document WO 2009/008036 A2 discloses the preamble of claim 1.

Summary

The present application describes a feeding boiler for heating water or other thermal fluid lines comprising a burner (1) having an own cleaning system; a combustion chamber (2); an heat exchanger (3) comprising a modular set where each module (31) is constituted by a hollow central body (32) with cooling fins and two caps (33) coupled at opposed faces of said heat exchanger (3), and a mechanical cleaning system (4) comprising of a group of cleaning modules (60) comprising a geometrical metallic structure (61) with an U shaped inverted geometry with upper axis (62) and lower axis (63), coupled to toothed sprockets (64) synchronized by gear chains (65), and a brush (67) that moves itself in synchrony with the gear chains (65) and makes said group of cleaning modules (60) to slide over the heat exchanger (3). According to the invention, the cleaning system of burner (1) used in the feeding boiler for heating water or other thermal fluid lines,comprises a scraper (17) whose lower surface is coincidental with the internal surface of the post-chamber (12), and an actuator (19).
In an embodiment, the cleaning system of burner (1) used in the feeding boiler for heating water and other thermal fluid lines comprises an inflation antechamber (10), coupled to a centrifugal fan (11), and a post-chamber (12), and the internal volumes of the inflation antechamber (10) and the post-chamber (12) are connected through small circular orifices (15).
In a further embodiment, the actuator (19) used in the feeding boiler for heating water or other thermal fluid lines, is placed outside the inflation chamber (10) and acts upon the scraper (17) by means of a shaft from the actuator system (18).
In another embodiment, the feeding boiler for heating water or other thermal fluid lines comprises a feeding channel (13) connected to the post-chamber (12), and an electrical resistance (14) placed into one of the orifices connecting the internal volume of the inflation antechamber (10) and the one of the post-chamber (12), and having the feeding channel (13) some through holes (16).
In another embodiment, the combustion chamber of the feeding boiler for heating water of other thermal fluid lines comprises a set of two hollow cylinders (21) and (22), whose free ends are connected by two identical caps (20) mounted in reverse, and the space between the hollow cylinders (21, 22) is filled with running water.
In still another embodiment, the ends of one of the caps (20) used in the feeding boiler for heating water or other thermal fluid, have coupled to them a redirecting component (23) .
In an embodiment, the caps (33) used in the feeding boiler for heating water or other thermal fluid lines seal together with the central body (32) and have two through holes, one at the upper end and other at the lower end of each cap (33), and a tubular interconnecting component (34) .
In another embodiment, the tubular interconnecting component (34) used in the feeding boiler for heating water or other thermal fluid lines, consists in a tube (35), with two external machined channels at opposite ends of the interconnecting component (34), and O-rings (36).
In still another embodiment, the feeding boiler for heating water or other thermal fluid lines comprises lower diverting boxes (41) and upper diverting boxes (51), respectively under and above the modules (31), each box (41, 51) diverting 180° the route of the gases.
In an embodiment, the brush (67) used in the feeding boiler for heating water or other thermal fluid lines, comprises a rigid elongate metallic central profile (68) with metallic fibers (69), which are braided along all the length and both sides of central profile (68).
In another embodiment, the lower diverting boxes (41) used in the feeding boiler for heating water or other thermal fluid lines, comprise a throttle type valve (42) acted by the toothed sprocket (44) coupled to the axis of rotation, and a central spinning shaft (43) that has sealing fins (45) .
In still another embodiment, the screw-worm (71) of the feeding boiler for heating water or other thermal fluid lines, transfers the ashes to outside the combustion chamber (2)

General description

The present invention describes a feeding boiler for heating water or other thermal fluid lines, comprising modular units of thermal transference, which can be jointly disposed by adding lateral modules of interconnection, thus forming the heat exchanger itself.
To ensure the cleaning of the modular unities exterior face, a mechanical and modular cleaning system has been added. Each module from the cleaning system allows for a cleaning of two modules external faces. In case this cleaning system were not contemplated, a soot or other combustion products accumulation would occur, in short / medium term, upon the external surfaces of the heat exchanger, what would increase the resistance to heat transfer and the loss of charge inside the route performed by the exhaust gases, whereby an overall thermal efficiency of the equipment where these module(s) would be installed would successively decrease.
The object of the technology now disclosed is thus to develop a modular heat exchanger allowing the satisfaction of several thermal capacities, and that could be used for heating any thermal fluid, including water. At the same time, it is intended that the modular components can be built in an efficient manner, at a reduced cost, due to the fact that all of them have the same generic configuration.
Similarly its assembly is simplified and to the measure of the thermal needs and available free space.
The indexed cleaning system also presents as a characteristic its modularity. With inclusion of this cleaning system in the heat exchangers it is aimed to solve the problems associated with efficiency of thermal transfer, related to the accumulation of solid material resulting from burning fuel upon the heat exchangers walls. This way the thermal efficiency is maintained, as well as the reduction of maintenance operations frequency, and increases the useful lifetime of the heat exchangers.
For already existing buildings with limited access, this type of heating boiler is the adequate solution, once that the modules can be carried separately and assembled in situ. The burner could be embedded into other industrial boilers burning biomass fuels to heat space and domestic hot water (DHW), industrial procedures needing heat, and boilers for services such as swimming-pools, service buildings, agricultural explorations and residential condominiums.

Brief Description of the Figures

For easier comprehension of the technic, are annexed figures presenting preferential embodiments which, however, are not intended to limit the object of present application.

Figure 1 illustrates a view from an embodiment of the heating boiler, where the reference numbers represent:
1. 1 - Burner;
2. 2 - Combustion chamber;
3. 3 - Heat exchanger;
4. 4 - Automatic cleaning system.
Figure 2 illustrates a view from an embodiment of the burner used in the heating boiler, where the reference numbers represent:
- 1 - Burner;
- 10 - Inflation antechamber;
- 11 - Centrifugal fan;
- 12 - Post-chamber;
- 13 - Feeding channel;
- 14 - Electrical resistance;
- 15 - Circular orifices;
- 16 - Through holes;
- 17 - Scraper;
- 18 - Actuator system shaft;
- 19 - Actuator.
Figure 3 illustrates a view from an embodiment of the combustion chamber used in the heating boiler, where the reference numbers represent:
- 2 - Combustion chamber;
- 20 - Caps;
- 21 - External hollow cylinder;
- 22 - Internal hollow cylinder;
- 23 - Redirecting component.
Figure 4 illustrates a view from an embodiment of the combustion chamber used in the heating boiler, where the reference numbers represent:
- 2 - Combustion chamber;
- 20 - Caps;
- 21 - Hollow cylinders;
- 23 - Redirecting component.
Figure 5 illustrates a view from an embodiment of the heat exchanger used in the heating boiler, where the reference numbers represent:
- 31 - Module;
- 32 - Central body;
- 33 - Cap;
- 34 - Tubular interconnecting component.
Figure 6 illustrates an exploded view from an embodiment of the heat exchanger used in the heating boiler, where the reference numbers represent:
- 31 - Module;
- 32 - Central body;
- 33 - Cap;
- 34 - Tubular interconnecting component.
Figure 7 illustrates a view from an embodiment of the tubular interconnecting component used in the heating boiler, where reference numbers represent:
- 34 - Tubular interconnecting component;
- 35 - Tube;
- 36 - O-rings.
Figure 8 illustrates a view from an embodiment of the connection between the heat exchanger cap, and the tubular interconnecting component used in the heating boiler, where reference numbers represent:
- 33 - Cap;
- 34 - Interconnecting component.
Figure 9 illustrates a view of the diverting boxes used in the heating boiler, where reference numbers represent:
- 3 - Heat exchanger;
- 31 Module.
Figure 10 illustrates a view of the diverting boxes used in the heating boiler, where reference numbers represent:
- 51 - Upper diverting boxes;
- 52 - Cleaning system bearings.
Figure 11 illustrates the gases route by action of the lower diverting boxes (41) and upper diverting boxes (51).
Figure 12 illustrates a view of the diverting boxes used in the heating boiler, where reference numbers represent:
51 - Upper diverting boxes.
Figure 13 illustrates a view of the diverting boxes used in the heating boiler, where reference numbers represent:
- 41 - Lower diverting boxes;
- 42 - Throttle type valve.
Figure 14 illustrates a view from the cleaning module used in the heating boiler, where reference numbers represent:
- 60 - Vertically moving comb;
- 61 - Metallic structure;
- 62 - Upper axis;
- 63 - Lower axis;
- 64 - Toothed sprockets;
- 65 - Gear chains;
- 67 - Brush.
Figure 15 illustrates a view of the cleaning module used in the heating boiler, where reference numbers represent:
- 60 - Vertically moving comb;
- 62 - Upper axis;
- 64 - Toothed sprockets;
- 66 - Common shaft;
- 67 - Brush.
Figure 16 illustrates a view from the brush used in the cleaning module of the heating boiler, where reference numbers represent:
- 67 - Brush;
- 68 - Central rigid profile;
- 69 - Metallic fibers.
Figure 17 illustrates a view from the throttle type valve used in the heating boiler, where reference numbers represent:
- 42 - Throttle type valve;
- 43 - Spinning central shaft;
- 44 - Toothed sprocket;
- 45 - Sealing fins.
Figure 18 illustrates a lateral view from the throttle type valve (42) in the open and shut positions.
Figure 19 illustrates a view from the combustion chamber used in the heating boiler, where reference numbers represent:
- 2 - Combustion chamber;
- 70 - V shaped deflector;
- 71 - Screw-worm.

Description of some embodiments

The description of the technology is made recurring to embodiments illustrated by the figures, and to the elements they contain, in order to make easy their description, interpretation of its operation and scope of their application. However this description is merely representative of one of possible compositions, dimensions and arrangements of components integrated in the system. In fact, the composition, size and disposition of those elements shall be adapted to the specific qualitative and quantitative needs required by each production.
This description will not be limited by theoretic considerations related to the different scientific and technological fields associated with heat transfer.
The present invention refers to a boiler of the type used for feeding heating lines for water or other thermal fluid, and is characterized in that it comprises a burner (1) which has an inflation antechamber (10), a post-chamber (12), and a cleaning system; a combustion chamber (2); an heat exchanger (3), and a mechanical cleaning system (4) comprising a group of cleaning modules (60) that slides over the exchanger (3).
The burner (1) has the function of promoting the combustion of combustible elements, e.g. pellets, and creating a flow of hot gases, whose temperatures range from 900 to 1400°C. Said burner (1) comprises an inflation antechamber (10), to which is coupled a centrifugal fan (11) and a post-chamber (12), where the pellets are deposited and into which a flow of air from the centrifugal fan (11) is injected. The internal volumes of the inflation antechamber (10) and of the post-chamber (12) are connected by means of small circular orifices (15), through which passes the air flow, injected in the inflation antechamber (10) by the centrifugal fan (11). A feeding channel (13) directly connected to the post-chamber (12), allows for the feeding of fuel flow, particularly pellets. An electrical resistance (14) installed in one of the orifices that connects the internal volumes of the inflation antechamber (10) and that of the post-chamber (12), allows for the beginning of pellets combustion by warming of injected air that is forced to contact with said electrical resistance (14). After the beginning of combustion, the electrical resistance (14) is turned off, maintaining it active indefinitely whilst the ratio between air flow and pellets remains inside an operation range.
As an additional safety measure, the feeding channel (13) possesses through holes (16) that allow for the passing of some of the air injected in the inflation chamber (10), in other words, there is a reduced flow of air that is injected into the post-chamber (12) from the feeding channel (13), thus being avoided that the phenomenon of back-burning occurs, in other words, that the flame flows through the pellets entrance channel in direction to the pellets silo.
The burner (1) disposes also of a cleaning system comprising a scraper (17) whose lower surface is coincidental with the internal surface of the post-chamber (12), and an actuator (19) placed outside the inflation antechamber (10), which allows for the actuation of the scraper (17) by means of a shaft of the actuator system (18) .
After the exhaustion of the gases from the burner (1), these pass to the combustion chamber (2) that consists in a set of two hollow cylinders (21) and (22), whose free ends are connected together by two identical caps (20), and assembled in reverse. The hollow cylinders (21, 22) have enough length for the developing of flame, the space between the hollow cylinders (21, 22) being filled in with running water in order to dissipate part of the heat, and so prevent the combustion chamber (2) to reach temperatures that would put in jeopardy its physical integrity. In one of the ends of one of the caps (20) a redirecting component (23) is connected in order to redirect the gases from the burner (1) to the heat exchanger (3). It is to point out that the redirecting component (23) does not possess heat dissipation. The water flow that is injected into the combustion chamber (2) is afterwards transferred to the heat exchanger (3).
From the combustion chamber (2) the gases are transferred to an input of the heat exchanger (3), which comprises a modular set, being each module (31) composed by a central finned and hollow body (32) and two caps (33) coupled at opposed faces of said heat exchanger (3). The caps (33), partially hollow, seal together with the central body (32) to create a volume to be filled with running water and having two through holes, one on the upper end, and the other on the lower end of each cap (33), which allow for the communication of water with the other modules after their assembly, using a tubular interconnecting component (34). This tubular interconnecting component (34) consists in a tube (35), with two external channels machined at opposed ends of the interconnecting component (34), for posterior location of O-rings (36), thus allowing for a sealed connection. At the ends of the heat exchanger (3), are placed modules, that on their external faces, not contacting with gases, do not possess any fins, being thus smooth, and so avoiding the occurrence of an heat transfer to the environment that would result in some losses.
After assembling the modules (31), although being automatically created a course for the runoff of the water, lower diverter boxes (41) and upper diverter boxes (51) are placed, respectively under and over the modules (31), which have a simple parallelepiped geometry and comprise 5 sealed faces and one that has an opening through which the gas reaches and leaves the box, in a manner that allows also for the creation of a route for the runoff of gases, and for the maximization of the heat transfer to the water, whereas each box (41, 51) diverts the route of the gases for 180°, as illustrated at Figure 11. This behavior can be continuously seen at the last upper diverter box (51), placed mandatorily over the exchanger (3), to which an electrical extractor can be coupled.
From the combustion process, particularly of pellets, results the creation of ashes that, due to its low granulometry, flow together with the combustion gases, and will deposit randomly during its route inside the boiler. Once that the greater heat exchange occurs inside the exchanger (3), the application of a cleaning system (4) in the exchanger (3), reveals itself essential. For it, a mechanical cleaning system (4) has been developed, which comprises a vertically moving comb (60) that cleans the exchanger fins as it passes. The cleaning system (4) comprises a set of cleaning modules (60) that slides over the exchanger (3), and where each cleaning module (60) allows for the cleaning of a pass of gases but, notwithstanding, after the installation of the necessary modules, these can be serially acted and by a single actuator.
The cleaning module (60) is constituted by a metallic structure (61) with an inverted U geometry, where each leg of the U possesses two axes at its most extreme points (62) and (63) where toothed sprockets (62) are coupled and synchronized through gear chains (65). The upper shafts of both legs are synchronized using a common shaft (66), supported by a set of bearings (52) present at the upper diverter box (51). Between both gear chains (65) of each leg, there is coupled a brush (67), which moves itself in synchrony with the chains (65). The mechanism is acted by the common shaft (66) coupled to a motor (not shown), using a gear chain. The motor rotation in one direction makes the brush (67) go down and the rotation in the inverse sense make it go up. The brush (67) comprises a rigid central profile (68), elongated and metallic, with metallic fibers (69), which are braided in it all along its length and both sides of the central profile (68).
The vertical movement of the brush (67) removes the ashes deposited upon the external surfaces of the heat exchanger modules (3). These are the main surfaces for the heat transfer between the gases and the water.
All the ashes removed by above referred system will, under the action of gravity, fall down and set inside the lower diverter boxes (41). In order to remove automatically these ashes, an also modular system has been developed, which extracts them from inside those lower diverter boxes (41). This system comprises a throttle type valve (42) which, installed with its rotation axis horizontally and as per a longitudinal direction of the section of the pass of gases between modules, allows by rotation the transfer of the mass of ashes to outside the lower diverter boxes (41), avoiding exhaustion/deviation of gaseous flow. The throttle type valve (42) is acted via toothed sprocket (44) coupled to the rotation axis and that possesses a central spinning shaft (43) having at a central zone sealing fins (45) in a number sufficient to create, when not spinning, a sealed volume upstream of said throttle type valve (42).
The mass of ashes removed by the throttle type valve (42) falls down over the outside of the combustion chamber (2), eventually circumventing it, for what the cleaning system (4) presents a V shaped deflector (70), and a screw-worm (71), under the combustion chamber (2). The V shaped deflector (70) allows funneling all the ashes expelled from the lower diverter boxes (41) to its base, where the screw-worm (71) is placed. Once acted, the screw-worm (71) transfers the ashes to outside the combustion chamber (2).
Naturally, present embodiment is not restricted to the embodiments described in this document, and a person with ordinary skill in the area could foresee many change possibilities in it, without departing from the general idea as defined by the claims.
All the above described embodiments are, obviously, combinable with each other. The following claims additionally define preferred embodiments.

Claims

Feeding boiler for heating water or other thermal fluid lines comprising a burner (1) comprising its own cleaning system; a combustion chamber (2); an heat exchanger (3) comprising a modular set where each module (31) comprises an hollow central body (32) and, two caps (33) coupled at opposed faces of said heat exchanger (3); the feeding boiler comprising also a mechanical cleaning system (4) composed by a group of cleaning modules (60), each cleaning module comprising a metallic structure (61) with a geometry in inversed U shape with an upper axis (62) and a lower axis (63), making the referred group of cleaning modules (60) to slide over the heat exchanger (3),
the feeding boiler being characterized in that each hollow body has fins, the upper (62) and lower axis (63) of the metallic structure (61) are both coupled to toothed sprockets (64) synchronized by gear chains (65), and the burner cleaning system comprises an actuator and a scraper whose lower surface is coincidental with the internal surface of the post-chamber.
Feeding boiler for heating water or other thermal fluid lines according to the previous claim, wherein the burner (1) comprises an inflation antechamber (10) coupled to a centrifugal fan (11), and a post-chamber (12), and the internal volumes of the inflation antechamber (10) and of the post-chamber (12) are connected through circular orifices (15).
Feeding boiler for heating water or other thermal fluid lines according to the previous claim, wherein the actuator (19) is placed outside the inflation chamber (10), and acts upon the scraper (17) by means of an actuator system shaft (18).
Feeding boiler for heating water or other thermal fluid lines, according to claim 2, comprising a feeding channel (13) connected to the post-chamber (12), and an electrical resistance (14) placed inside one of the orifices linking the internal volume of the inflation antechamber (10) and the post-chamber (12), and the feeding channel (13) possesses through holes (16) .
Feeding boiler for heating water or other thermal fluid lines according to claim 1, wherein the combustion chamber (2) comprises a set of two hollow cylinders (21) and (22), whose free ends are connected together by means of two identical caps (20) reversely assembled, and the space between the hollow cylinders (21, 22) is filled with running water.
Feeding boiler for heating water or other thermal fluid lines according to the previous claim, wherein the ends of one of the caps (20) has coupled to it a redirecting component (23).
Feeding boiler for heating water or other thermal fluid lines according to claim 1, wherein the caps (33) seal together with the central body (32), and possess two through holes, one at the upper end and other at the lower end of each cap (33), and a tubular interconnecting component (34).
Feeding boiler for heating water or other thermal fluid lines according to the previous claim, wherein the tubular interconnecting component (34) consists in a tube (35), with two external channels machined at opposite ends of the interconnecting component (34), and O-rings (36).
Feeding boiler for heating water or other thermal fluid lines according to claim 1, comprising lower diverting boxes (41) and upper diverting boxes (51), respectively under and over the modules (31), and each of the boxes (41, 51) diverts the gases route by 180°.
Feeding boiler for heating water or other thermal fluid lines according to claim 1, wherein brush (67) is made of a rigid elongated metallic profile (68) with metallic fibers (69) that are braided along its full length, and at both sides of central profile (68) .
Feeding boiler for heating water or other thermal fluid lines according to claim 9, wherein the lower diverting boxes (41) comprise a throttle type valve (42) acted by toothed sprockets (44) coupled to the rotation axis, and a spinning central shaft (43), which has sealing fins (45).
Feeding boiler for heating water or other thermal fluid lines according to claim 9, wherein the cleaning system (4) presents a V shaped deflector (70), and a screw-worm (71) under the combustion chamber (2), and the V shaped deflector (70) funnels the ashes expelled from the lower diverting boxes (41) to its base.
Feeding boiler for heating water or other thermal fluid lines according to the previous claim, wherein the screw-worm (71) transfers the ashes to outside the combustion chamber (2).