Stove with built-in boiler for hot water production

Abstract

 The present invention relates to a stove with built-in boiler for hot water production, which comprises a fire-box in which comburent air flows also when the mouth used to load wood is closed by the door, thanks to a series of intake openings that can be obstructed from the inside by means of a collapsible intercepting screen actuated by an electric engine controlled by a thermostat that closes the openings when hot water reaches the temperature set on the thermostat.

Description

[0001] The present patent application for industrial invention relates to a stove with built-in boiler for the production of hot water used for sanitary services and/or radiator heating installations.

[0002] Stoves using the heat produced by the combustion of wood to warm up the air in the room and the water contained in one or more exchangers located in the fire-box, from which water is obtained for sanitary or heating use, have been known for a long time.

[0003] The major drawback of the stoves of known type consists in the lack of a device able to adjust the flame according to the temperature reached by the water contained in the exchangers, where water temperature of course varies according to the water load absorbed by utilities.

[0004] This means that during the operation of the stove, sometimes combustion could be slowed down, if not interrupted, being worthless to burn wood once the water has reached a temperature value sufficient to feed utilities.

[0005] Stoves of known type are not provided with automatic devices for flame adjustment and the flame is always on, bringing hot water to maximum temperature values, which may be excessive for the requested use.

[0006] The main purpose of this invention is to significantly improve the thermal efficiency of this type of stoves, first of all by eliminating the energy waste that occurs today when combustion remains unaltered when the request for water from utilities has ceased.

[0007] To this end, the stove of the invention has been provided with a device capable of turning the flame on and off according to the temperature reached by hot water. In this way, combustion is interrupted when the set temperature value is reached, and then automatically restored when the water temperature falls below the threshold value.

[0008] It must be noted that the energy saving resulting from the use of such an adjustment device is not only related to the elimination of thermal waste, being also determined by the capability of setting the hot water temperature as desired by the user.

[0009] In other words, the stove of the invention allows reducing fuel consumption according to external climatic conditions or personal user requirements.

[0010] In order to improve thermal efficiency, the location and direction of exchangers inside the fire-box have been suitably chosen to force combustion products along an ascending travel, thus favouring maximum thermal exchange and at the same time preventing the formation of sooty deposits on thermal exchange surfaces.

[0011] As it is known, the said deposits adversely affect transmittance and for this reason, the current models of stove need periodical cleaning on annual basis. Tests carried out on the stove of the invention have shown practically unchanged transmittance after several years of operation.

[0012] The stove of the invention comprises a fire-box that is hermetically closed by a front door with shutter.

[0013] When closed, the door comes in contact with a border that borders the mouth of the stove and has a series of through openings, through which external air can enter the fire-box to feed combustion.

[0014] The air flow through the openings can be interrupted by means of a collapsible intercepting screen located immediately behind the border and capable of assuming two different positions, which correspond to total closing or total opening of the openings.

[0015] The collapsible intercepting screen can be raised or lowered by means of a lever system actuated by an electric engine controlled by a thermostat and provided with a device that determines inverse rotation at every start.

[0016] The fire-box has a parallelepiped shape and is provided with walls with a space filled with water; a first bracket projects from the back vertical wall and transversally extends from one side to the other, being interrupted near the front wall, slightly above the mouth of the stove.

[0017] The first bracket has a space that receives the water coming from below through a first ascending pipe which communicates with the space of the back wall.

[0018] A second ascending pipe starts above the first bracket and ends in the space of a second projecting bracket, which is fixed inside the front wall and transversally extends from one side to the other, being interrupted near the back wall, slightly above the first bracket.

[0019] The second bracket communicates with the space on top of the fire-box, where the hot water feed union is located, while the cold water input union for the cold water returning from the radiators is located under the bottom wall of the fire-box.

[0020] For major clarity the description of the stove according to the present invention continues with reference to the enclosed drawings, which are intended for purposes of illustration only and not in a limiting sense, whereby:

• Fig. 1 is an axonometric diagrammatic view of the stove of the invention;
• Fig. 2 is a cross-section of the stove of the invention with vertical plane II-II, shown in Fig. 3;
• Fig. 3 is a cross-section of the stove of the invention with vertical plane III-III, shown in Fig. 2.

[0021] With reference to the aforementioned figures, the stove of the invention comprises a metal bearing structure closed by a series of metal walls that enclose the fire-box (1) with parallelepiped configuration, surrounded by six walls provided with intercommunicating spaces (A) filled with water.

[0022] The hot water feed union (2) is located on top of the fire-box (1), which is of course provided with the fume ejection mouth (3), on which the pipe used to convey fumes to the chimney is inserted.

[0023] The front wall is interrupted to create the mouth (4) used to load the wood, closed by a door (5) with shutter, which is inserted and guided between two upright guides (6) fixed outside the front wall.

[0024] When the door (5) is closed, comburent air can still enter the fire-box (1) through a series of intake openings (7) located on the front border (8) that borders the mouth (4) and comes into contact with the door (5) when the same is closed.

[0025] Immediately inside the border (8) a collapsible intercepting screen (9) capable of intercepting the air flow through the openings (7) is located, thus contributing comburent air to combustion inside the fire-box (1).

[0026] The collapsible intercepting screen (9) can be raised or lowered automatically by means of a lever system (10) actuated by an electric engine (11) controlled by a thermostat (12) located on the control panel (13) where the user can set the water threshold temperature to turn the flame on and off.

[0027] It appears evident that the interruption of comburent air to the flame causes the spontaneous interruption of combustion; likewise, the restitution of comburent air to burning ember determines the spontaneous recovery of combustion.

[0028] In order to force fumes along a winding travel inside the fire-box (1), a first bracket (14) projects from the back wall and transversally extends from one side to the other, being interrupted near the front wall, slightly above the mouth (4).

[0029] The first bracket (14) has a space that is filled with water coming from below through a first ascending pipe (15) that communicates with the space of the back wall.

[0030] A second ascending pipe (16) starts above the first bracket (14) and ends into the space of a second projecting bracket (17), which is fixed inside the front wall and transversally extends from one side to the other, being interrupted near the back wall, slightly above the first bracket (14).

[0031] The second bracket communicates with the space on top of the fire-box where the hot water feed union (2) is located.

[0032] As shown by the arrows (F) of Fig. 2, ascending combustion products are intercepted by the first bracket (14), which deviates them downwards and forward, and then lets them raise under the second bracket (17), which imposes the same downward deviation above the first bracket (14), finally letting them free to raise towards the ejection mouth (3).

[0033] The high inclination and opposite location of the two brackets (15 and 17) force fumes to travel along a double serpentine which extends their permanence in the fire-box (1), thus favouring thermal exchange especially with respect to the water contained in the brackets (15 and 17), which are in contact with fumes.

[0034] The high downward inclination of the brackets (15 and 17) obstacles the formation of sooty deposits on the brackets.

Claims

1. Stove with built-in boiler for hot water production, of the type comprising a fire-box (1) surrounded by metal walls with intercommunicating spaces (A) filled with water, with the front wall being interrupted to leave space to the mouth (4) used to load wood, closed by a door (5), whose lower border comes in contact with a border (8) that borders the mouth (4), it being characterised by the fact that the border (8) has a dense series of through openings (7) that can be internally obstructed by a collapsible intercepting screen (9) actuated by an electric engine (11) controlled by a thermostat (12).

2. Stove as defined in the preceding claim, characterised by the fact that the fire-box (1) has a parallelepiped shape and is surrounded by six walls.

3. Stove as defined in the preceding claims, characterised by the fact that the door (5) is a shutter and slides between two upright guides (6) fixed outside the front wall of the fire-box (1).

4. Stove as defined in claims 1 and 2, characterised by the fact that the fire-box (1) contains:

- a first bracket (14) that projects from the back wall and transversally extends from one side to the other, being interrupted near the front wall, slightly above the mouth (4);

- a first ascending pipe (15) that communicates the space of the back wall of the fire-box (1) with the space of the first bracket (14);

- a second projecting bracket (17) fixed inside the front wall of the fire-box (1) that transversally extends from one side to the other, being interrupted near the back wall, slightly above the first bracket (14);

- a second ascending pipe (16) that starts from the first bracket (14) and ends into the space of the second bracket (17), which communicates with the space on top of the fire-box (1) provided with the hot water feed union (2).

Drawing