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(11) | EP 3 242 094 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | BOILER WITH PREDETERMINED DIMENSIONS, BUT SUITABLE FOR CONTAINING HEAT EXCHANGERS WITH DIFFERENT DIMENSIONS |
| (57) A boiler for heating rooms and producing sanitary water, said boiler comprising a
tubular cylindrical body or ferrule (26), end closing elements coupled with opposite
ends of such body and a heat exchanger (2, 3) through which a fluid flows and placed
inside the assembly formed of such body or ferrule (26) and end elements, internally
to said heat exchanger (2, 3) a gas burner (21) being present, suitable for heating
said fluid flowing through the heat exchanger (2, 3), at least one of said end elements
comprising a frame (1) which said heat exchanger rests on. The frame (1) has a predetermined
outer diameter (K) so as to define an end element with constant dimensions associated
with a body also having a fixed outer diameter, the frame (1) co-operating alternatively
with at least two heat exchangers (2, 3) having different heat exchanging surfaces.
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[0001] The scope of the present invention is a boiler for heating rooms and producing sanitary water, according to the preamble of the main claim.
[0002] A boiler of the type mentioned above comprises a tubular cylindrical body (or ferrule or external shell) and end and opposed closing elements (or end plate). Inside such body there is placed a heat exchanger or (single or concentric spiral) coil through which water flows, said heat exchanger being usually placed in correspondence with a gas burner; for instance, such burner is arranged coaxially within the coil or tube nest of the heat exchanger. The water that flows through the latter is heated by the flame generated by the burner and/or by the smokes that generate in the boiler (or better, in a combustion chamber thereof which contains the coil and the burner) as a result of the operation of the burner.
[0003] In the traditional boilers of the type indicated above, the heating power also depends on the quantity of water that flows through the tube nest or coil. Note that the latter can be a single tube or a double tube one, one tube being inserted in the other.
[0004] Therefore, a mode to increase such power is that of modifying the dimensions of the individual turns of such tube nest as measured orthogonally to its own longitudinal axis. In other words, in such mode coils are used with different outer diameters, the inner diameter being equal.
[0005] In this way, the heat exchanging surface of the coil (through which water flows) and consequently the heating power of the boiler increase.
[0006] However, in such known operating mode boilers with coils of different diameters have different geometrical characteristics or different outer diameters as a function of the heating power generated by them. For this reasons boiler manufacturers have to realize bodies and end closing elements with different dimensions (diameters), which results in high industrial production costs and non negligible storage costs.
[0008] An object of the present invention is to offer a boiler that is capable of generating different heating powers, while having overall production costs reduced with respect to the known solutions.
[0009] Another object of the invention is to offer a boiler of the mentioned type that allows manufacturers to standardize their productions as much as possible.
[0010] Another object of the invention is to offer a boiler of the mentioned type that is easy to assemble and wherein this operation is obtainable in a short time, whatever the heating power generated by them is.
[0011] These objects and others that will be apparent to those skilled in this sector are achieved by a boiler according to the attached claims.
[0012] For a better understanding of the invention the following drawings are attached for merely explanatory, hence non limitative purposes, wherein:
figure 1 shows a partially cross-sectional schematic view of a first embodiment of a part of a boiler according to the invention;
figure 2 shows a partial top view of the part shown in figure 1;
figure 3 shows a view similar to that of figure 1, but of a different embodiment of the part of the boiler shown therein;
figure 4 shows a partial top view of the part shown in figure 3;
figure 5 shows a perspective view of a boiler according to the invention, in which some parts are omitted for the sake of clarity; and
figure 6 shows a schematic cross-sectional view of a boiler according to the invention, but comprising a horizontal heat exchanger instead of a vertical heat exchanger as illustrated in the previous figures and in which some parts are omitted for the sake of clarity.
[0013] With reference to the mentioned figures, they show a single frame 1 of a gas boiler associated with two coils or tube nests 2 and 3, having a circular cross-sectional shape (each defining a heat exchanger), comprising an identical outer diameter D, for instance equal to approximately 280 mm, and different inner diameters d1 and d2; for instance, the tube nest 2 in figures 1 and 2 has a diameter d1 equal to approximately 170 mm, whereas the tube nest or coil 3 in figures 3 and 4 has a diameter d2 equal to approximately 190 mm. It consequently follows that the cross-section S1 of the coil 2, i.e. the distance between two portions 5 and 6 of the wall 7 of every turn 8 as measured on a plane P orthogonal to a longitudinal axis W of the coil, is greater than the corresponding section S2 of the coil 3; consequently, the heat exchanging surface of the coil 2 is greater than that of the coil 3 and the inner cross-section of the coil 2 is greater than that of the latter. Consequently, a bigger quantity of water flows through the tube nest 2 as compared to that which flows through the tube nest 3 which, consequently, the boiler being in operation, enables the latter to generate a heating power smaller than that of the boiler to which the tube nest coil 2 belongs.
[0014] More specifically, the frame 1 comprises an annular body 10 having a predetermined diameter K and comprising a flat portion 11 from the edges of which an inner substantially vertical shoulder 12 (as referred to the longitudinal axis W of every heat exchanger that is coaxial to the frame) and a substantially vertical shoulder 13, i.e. a shoulder located on a side of the coil 8, depart. The shoulder 12 is spaced away from an upper face 15 of the flat portion 11 (with reference to the figures) and delimits a bore 17 of the annular body 10, whereas the outer shoulder 13 bends parallel to the heat exchanger 2 or 3 and is externally at least close to the latter in its most distant part from the axis W. Such shoulder 13 is close to the outer portion 6 of the wall 7 of the turn 8A located at a first end of the tube nest 2 or 3, which turn is in contact with a lower face 20 of the flat portion 11 of the frame 1.
[0015] Inside the bore 17 a usual gas burner is inserted as schematically shown in figures 1, 3, and 6 and identified by the numeral 21.
[0016] The frame 1 also comprises cylindrical bodies 23 and outer perforated tabs 24, suitable for making it possible to constrain it, by way of tie rods 57, to another portion or end element or end plate 59 of the boiler; such frame also comprises, at the free end of the outer shoulder 13, a part 25 suitable for coupling with a cylindrical tubular body 26 (or ferrule or external shell) of the boiler.
[0017] Therefore, thanks to the invention a single frame 1 having a predetermined diameter K which, in turn, defines predetermined dimensions of the cylindrical tubular body and of the outer terminal elements of the boiler, makes it possible to obtain boilers with different heating powers. As a matter of fact, as a function of the market needs or requirements, a manufacturer can couple the frame 1 with at least two different coils 2 and 3 of different inner diameters or different flow rates of a heated fluid (usually water) and subsequently associate with such frame the cylindrical tubular body 26 (indicated in dotted lines in figures 1 and 3) and shown in figures 5 and 6 and other usual components (including, water supply connectors 62 and exhaust connectors 63 for a heating system of a room in which the boiler is located and for the sanitary fittings of such room) even associated with the end element 59 to complete the boiler. In correspondence with the latter, on the body 26 there is possibly present an adjustable end plate 68, close to the second end 31 of the coil 2 or 3 distant from the turn 8A close to the frame. Note that the position of such end plate can be adjusted in the cylindrical body in order to bring it closer or move it away from such end 31 so as to make it possible to create, or not, a high efficiency, low emissions boiler, by preventing the steam present in the combustion smokes from being exhausted.
1. A boiler for heating rooms and producing sanitary water, said boiler comprising a
tubular cylindrical body or ferrule (26), end closing elements (1, 59) coupled with
opposed ends of such body and a heat exchanger (2, 3) through which a fluid flows
and placed inside the assembly formed of such body (26) and end elements, inside such
heat exchanger (2, 3) a gas burner (21) being present and being suitable for heating
said fluid flowing through the heat exchanger (2, 3), at least one of said end elements
comprising a frame (1) on which said heat exchanger rests, characterized in that the frame (1) has a predetermined outer diameter (K) so as to define an end element
with constant dimensions associated with a body also having a fixed outer diameter,
the frame (1) co-operating alternatively with at least two heat exchangers (2, 3)
having different heat exchanging surfaces.
2. A boiler according to claim 1, characterized in that every heat exchanger comprises a coil or tube nest (2, 3) constrained to such frame,
connectors (62, 63) being provided to supply and exhaust the fluid in/from said coil
(2, 3), the connection of the latter to said connectors associating the heat exchanger
(2, 3) with said frame (1) in a stable manner.
3. A boiler according to claim 2, characterized in that said connectors (62, 63) are placed in correspondence with such frame (1) and with
the extremal closing element (59) located at the opposite end of the tubular body
or ferrule (26) with respect to the frame (1).
4. A boiler according to claim 1, characterized in that the coils (2, 3) that can be associated with said frame (1) have an identical outer
diameter (D), but different inner diameters (d1, d2).
5. A boiler according to claim 1, characterized in that the coils (2, 3) that can be associated with said frame (1) have an identical inner
diameter, but different outer diameters.
6. A boiler according to claim 1, characterized in that said frame (1) has an annular body (10) having a flat portion (11) delimiting an
inner bore (17) wherein a gas burner (21) is inserted, said flat portion (11) having
an inner edge from which an inner shoulder (12) rises and having an outer edge from
which an outer shoulder (13) rises, such shoulders (12, 13) are directed to opposite
directions, the outer shoulder (13) being at least close to an outer portion (6) of
a wall (7) of a turn (8A) located at a first end of the heat exchanger (2, 3), such
turn being in contact with a face (20) of said frame (1).
7. A boiler according to claim 6, characterized in that said outer shoulder (13) comprises a part (25) suitable for co-operating with the
tubular body (20) of the boiler, said part (25) being preferably preset to such cooperation.
8. A boiler according to claim 1, characterized in that it comprises an adjustable end plate (68) located in proximity to a second end (31)
of said exchanger (2, 3) distant from the frame (1).
9. A boiler according to claim 1, characterized in that the heat exchanger (2, 3) can have spatial arrangements alternatively put at 90°
from each other or a vertical or horizontal arrangement.