The invention concerns a boiler designed for central heating and domestic hot water installations.

Known from patent document EP 0 926 439 A2 is a gas-fired boiler featuring a gas combustion chamber and a system of pipes to discharge the combustion gases. The combustion chamber and the pipes to discharge the combustion gases are placed in a tank filled with water. The combustion chamber is closed on top with a lid featuring an opening for the burner. The lid incorporates a thermo-insulating material.

Known from document PL 216 290 B1 is a heat exchanger having a fluid chamber encased in an outer jacket with fluid inlet and outlet, inside which there is a combustion chamber and a set of vertical pipes for the flow of the fumes. The combustion chamber is closed on top with a lid featuring an opening for the burner.

In the known solutions the lid of the combustion chamber is a separate element which is thermally insulated and needs to be sufficiently sealed. In addition to the problems with achieving the required tightness and insulation of the lid, the known solutions are costly.

This invention solves the technical problem related to the required sealing and insulation of the combustion chamber lid, and the related high costs. Moreover, it solves the problem of losses of the heat accumulating in the layer insulating the combustion chamber.

The problems were solved by developing a new structure of the heat exchanger lid to replace the standard insulation and sealing of the lid, and by developing new circulation of the boiler water.

In accordance with this invention, a boiler incorporating a jacket with a package of vertical fume pipes mounted inside it, where on the one side the pipes are connected to the combustion chamber placed inside the said jacket, and where the chamber is closed with a lid featuring an opening for the burner, and on the other side the pipes are connected to a condensate accumulation bowl, the burner further featuring an inlet and outlet stub pipes for the boiler water and an outlet stub pipe for the fumes, and where the inside of the said jacket forms the main chamber for the boiler water is characterized in that the lid incorporates two plates positioned one below the other, namely the outer plate and the inner plate which is connected to the combustion chamber, where the said plates are mounted at a distance to each other and are connected to each other via the side wall so that formed between the said plates is an additional chamber for the boiler water linked to the main chamber for the boiler water.

Preferably, the inner plate of the lid extends outside beyond the side wall of the lid.

In one variant of the invention the outer plate of the lid is connected to the jacket, with a slit formed between the inner plate and the jacket for the flow of the boiler water, where there are openings in the side wall of the lid which link the main boiler water chamber to the additional boiler water chamber, and preferably there is an outlet boiler water stub pipe mounted on the jacket.

In another variant of the invention, the inner plate of the lid is connected to the jacket and features at least one opening which links the main boiler water chamber to the additional boiler water chamber, and preferably there is an outlet boiler water stub pipe in the outer plate of the lid.

Preferably, the lid is integrated with the jacket via a welded connection.

The solution according to the invention ensures better use of the heat thanks to the forced circulation of the boiler water in the hot lid. Moreover, the integral connection of the lid and jacket by way of welded connections ensures absolute tightness.

The invention is shown in embodiments on the drawings, where:

• Fig. 1 presents the boiler partially in axial section, in a 3D view, in the first embodiment;
• Fig. 2 shows the lid partially in cross-section, in a 3D view, in the first embodiment;
• Fig. 3 depicts the boiler partially in axial section, in a 3D view, in the second embodiment;
• Fig. 4presents the lid partially in cross-section, in a 3D view, in the second embodiment.

An exemplary boiler incorporates a jacket 1 with a package of vertical fume pipes 2 mounted inside it, where on the one side the pipes are connected to the combustion chamber 3, and on the other side to a condensate accumulation bowl 4. The fume pipes 2 are mounted in the sieve bottoms: upper 5 and lower 6. The combustion chamber 3 is placed inside the jacket 1, in its top part. The upper sieve bottom 5 forms the bottom of the combustion chamber 3. The inside of the jacket 1 forms the main chamber 7 for the boiler water in which the fume pipes 2 and the combustion chamber 3 are immersed. The combustion chamber 3 and the jacket 1 are closed with a lid 8. The lid 8 features two plates: the inner plate 8a which is connected to the combustion chamber 3, and the outer plate 8b which is situated above the inner plate 8a. The said plates 8a, 8b, are placed at a distance to each other and connected to each other via the side wall 8c, so that the inner plate 8a extends outside beyond the side wall 8c. Formed in between the said plates 8a, 8b, is an additional chamber 9 for the boiler water linked to the main chamber 7 for the boiler water.

In the first embodiment shown on Fig. 1 and Fig. 2, the outer plate 8b of the lid 8 is connected to the jacket 1, whereas between the outer plate 8a and the jacket 1 is a slit 18 for the flow of the boiler water, and the side wall 8c of the lid 8 features openings 19 which link the main chamber 7 for the boiler water to the additional chamber 9 for the boiler water. The outlet stub pipe 12 for the boiler water is mounted on the side wall of the jacket 1.

In the second embodiment shown on Fig. 3 and Fig. 4, the inner plate 8a of the lid 8 is connected to the jacket 1 and features one or more openings 10 which link the main chamber 7 for the boiler water to the additional chamber 9 for the boiler water. Mounted in the outer plate 8b of the lid 8 is an outlet stub pipe 12 for the boiler water.

In both embodiments, the inlet stub pipe 11 for the boiler water is placed in the bottom part of the jacket 1. Moreover, the lid 8 is fitted with an opening 13 for the burner, socket 15 for an ionisation probe to measure the current flowing through the flame and detect whether the flame continues to burn in the burner, socket 16 for an ignition electrode which generates a sparkle to the ground and is responsible for igniting the gas on the boiler burner, and socket 17 for the viewing device which makes it possible to check visually through observation whether the flame on the burner continues to burn. Moreover, the jacket 1 is fitted with an outlet stub pipe 14 for the fumes.

The lid 8 is integrated with the jacket and combustion chamber via a welded connection.

The boiler water circulation in the solution according to the first embodiment of the invention is as follows. Boiler water supplied to the main chamber 7 via the inlet stub pipe 11 flows towards the lid 8 in the direction opposite to the direction of flow of the fumes in the fume pipes 2, and while flowing, the water washes around the hot fume pipes 2, whereupon it washes around the combustion chamber 3 and via the slit 18 it flows onto the extending part of the inner plate 8a, following which, through the openings 19 in the side wall 8c of the lid 8 it flows into the additional chamber 9 from where it is drawn through the outlet stub pipe 12 located in the top part of the jacket.

The boiler water circulation in the second embodiment differs from the circulation described in the first embodiment in that the boiler water flows into the additional chamber 9 through the opening(s) 10 in the inner plate 8a of the lid 8, from where it is drawn through the outlet pipe 12 located in the outer plate 8a of the lid 8.

1-

jacket

2 -

fume pipes

3 -

combustion chamber

4 -

condensate accumulation bowl

5 -

upper sieve bottom

6 -

lower sieve bottom

7 -

main boiler water chamber

8 -

lid

8a -

inner plate of the lid

8b -

outer plate of the lid

8c -

side wall of the lid

9 -

additional boiler water chamber

10 -

opening in the inner plate of the lid

11 -

inlet stub pipe for boiler water

12 -

outlet stub pipe for boiler water

13 -

opening in the lid for the burner

14 -

outlet stub pipe for the fumes

15 -

socket for the ionisation probe

16 -

socket for the ignition electrode

17 -

socket for the viewing device

18 -

slit between the inner plate of the lid and the jacket

19 -

openings in the side wall of the lid