Fire tube boiler

SMOKE TUBE BOILER

DESCRIPTION

The invention refers to a fire tube boiler.

It is known that the heat source of heating systems requiring high power is often created by a battery of fire-tube boilers connected in parallel.

In conditions of high heat demand, the battery described operates optimally because all the component boilers, appropriately balanced, are in operation, but when the heat demand decreases, the burner of one or more boilers switches off: thus the relative boiler remains unused with all the negative consequences notoriously resulting from the loss of continuity of operation.

The aim of this invention is to create a fire tube boiler that can be installed as a heat source in heating systems requiring high power, ensuring continuity of operation even when the temperature varies.

MI153370 of the heat demand regime.

The proposed task, as well as other objects which will become clearer hereinafter, are achieved by a fire tube boiler, according to the invention, characterised in that it comprises the features set out in the following claim.

Further features and advantages of the invention will become clearer from the description of two preferred but not exclusive embodiments of the invention, illustrated by way of example and not by way of limitation in the attached drawings in which:

- figures 1 and 2 represent a battery of boilers connected in parallel according to the known technique, in two different operating conditions;

- figure 3 represents in section the boiler according to the invention in accordance with a first embodiment;

- figure 4 represents the boiler according to the invention in accordance with a second form of

MI153370 realization.

With reference to figures 1 and 2, 1 and 2 indicate two fire tube boilers according to the known technique, connected in parallel to form a battery.

Boilers 1 and 2 are identical, and so boiler 1 comprises a casing 3 to contain the water to be heated 4, equipped at the top with a firebox 5 in which the flame produced by a burner 6 develops.

The hearth 5 has a base shaped like a tube plate 7 from which a plurality of tubes 8 branch off which are immersed in the water to be heated 4 and convey the fumes produced in the hearth 5 to a collection chamber 9 which is conveyed to the chimney.

Boiler 2 is identical, as mentioned.

The situation shown in figure 1 is that of full-scale operation: burner 6 of boiler 1 and the equivalent of boiler 2 are on as highlighted in the figure, and so both boilers, appropriately balanced, are in

MI153370 works and the situation is optimal.

Figure 2 instead shows the situation that occurs following a drop in heat demand: the burner of boiler 2 has switched off, and consequently the entire boiler 2 remains unused.

Figure 3 shows a first embodiment 10 of a boiler according to the invention, which comprises a casing 11 for containing the water to be heated 12, with connections Ila, llb for inlet and outlet respectively.

Inside the casing 11 there are two hearths 13 and 14 with relative burners 13a, 14a, equipped with a common base consisting of a tube plate 15 which is thus in communication with both hearths 13 and 14.

Connected to the tube plate 15 are tubes 16 of the tube bundle which are immersed in the water to be heated and convey the fumes produced in the two furnaces 13 and 14, or in at least one of these, to a collection chamber 17.

MI153370 and conveyance to the chimney.

When only one of the burners is in operation, as in the case of figure 3 where only burner 13a is on, the fumes produced by it affect all the tubes of the tube bundle, according to the arrows in the figure, with consequent full use of the boiler and with the additional advantageous feature of obtaining a strong reduction in the temperature of the outgoing fumes, with a consequent increase in efficiency, due to the large exchange surface area that is offered to the fumes themselves in the indicated condition.

Figure 4 represents a second embodiment of the invention in which two hearths 18 and 19 with respective burners 18a, 19a, instead of being placed side by side as in the embodiment of figure 3, are superimposed, but still both in communication with a tube plate 20 to which are connected tubes 21 of the tube bundle which are immersed in the water to be heated and convey the fumes produced in both hearths, or in just one of these.

MI153370 as is the case in figure 4 in which only the burner 18a is lit with the flow of fumes highlighted by the arrows, to a collection chamber 22.

In practice, it has been found that the boiler according to the invention fully fulfills the intended task.

The invention described is susceptible to numerous other modifications and variations, all of which fall within the scope of the inventive concept; furthermore, all the details may be replaced with other technically equivalent elements.