WO1990007089A1

WO1990007089A1 - A stove

Info

Publication number: WO1990007089A1
Application number: PCT/SE1989/000676
Authority: WO
Inventors: Loqvist Kaj-Ragnar
Original assignee: Wave Energy Development Ab
Priority date: 1988-12-14
Filing date: 1989-11-21
Publication date: 1990-06-28
Also published as: SE8804510L; SE8804510D0; FI912776A0; DK111491A; SE469911B; DK111491D0; DK168131B1

Abstract

The present invention relates to a solid-fuel burning stove comprising an outer casing (14) and an openable and sealable front (1). The stove further comprises two mutually adjacent combustion chambers (6, 7) and a duct (11) which connects the two chambers at the bottom thereof. A first (7) of the two combustion chambers is constructed so that the solid fuel (9) charged thereto will burn from the bottom thereof, and the gases of combustion generated in this combustion chamber are conducted to the second (6) of the combustion chambers through the duct (11). The second combustion chamber (6) is intended to form an after-burner chamber with respect to the first combustion chamber (7) and also to form a fireplace in which solid fuel will burn with a higher flame. Fuel can be burned in either the first (7) or the second (6) of the combustion chambers, either separately or simultaneously.

Description

A STOVE

The present invention relates to a stove, and more particularly to a stove for burning solid fuel and being of the kind which comprises an outer casing or jacket having an openable and sealable front and incor¬ porating two mutually adjacent fuel-combustion cham¬ bers, and a flue duct which places the lower parts of the said chambers in communication with one another.

One of the drawbacks inherent with known metal-plate or cast-iron stoves is that the outer casing or jacket thereof becomes hot much too quickly. In some cases, stoves or this kind are lined with ceramic material, so that complete combustion (hotter combustion) is achie¬ ved more efficiently. In these cases, however, the stove contains no other heat-absorbing surface than the actual ceramic lining itself. Another drawback with stoves of this kind is that they include no form of afterburning chamber by means of capable which combus¬ tion can be enhanced. The flue gases generated by com¬ bustion quickly become superheated and the temperature of the gases exiting from the combustion chamber become unnecessarily high. Larger systems intended for heating single-unit dwellings for instance have a fuel-magazine in the fuel burns from the bottom, but these systems lack the ability of providing a "cosy fire" of a room or an "open-fire atmosphere" and neither are these systems constructed in accordance with "a furnace with- in a furnace" principle. Known solid-fuel burning stoves also have limited possibility of burning a given quantity of fuel slowly over a given unit of time with an optimum output of heat, without the fuel becoming rapidly ignited and burning with a high flame within a short space of time.

The object of the present invention is to eliminate the aforesaid drawbacks inherent with known solid-fuel burning stoves and, at the same time, to provide a stove which will burn fuel more effectively and in a manner which is friendly to the surroundings.

Accordingly, the inventive stove is characterized in that a first of the two combustion chambers is intended for slow-burning of the fuel charged thereto; in that the duct is operative to conduct gases of combustion from the first combustion chamber to the second of said two combustion chambers; in that the second combustion chamber is intended to function as an afterburner with respect to the first combustion chamber and also as a so-called fireplace in which solid fuel will burn with a higher flame; and in that the stove is constructed to enable solid fuel to be burned in either one of said chambers, separately or both at the same time.

So that the invention will be more readily understood and further features thereof made apparent, an exempli¬ fying embodiment of the invention will now be described in more detail with reference to the accompanying sche- atic drawings, in which

Fig. 1 is a front view of a stove constructed in accordance with the invention;

Fig. 2 is a view similar to Fig. 1 but with the front of the stove removed for illustration purposes; and Fig. 3 is a sectional view taken on the line III-III in Fig. l.

The illustrated stove has two front doors 1, a base or stand 2 and a flue pipe 3, which is provided with insulation 4. The stove further comprises two combus¬ tion chambers 6, 7, each of which has a respective ash box 5. The combustion chamber 6 shown to the left of Figs. 1 and 2 is fitted with a heat-reflecting device 8.

As shown in Fig. 2, the other fireplace 7 has a fuel- box 9 into which fuel, e.g. logs, wood, coal is charged through a hatch 10. The fuel store or heat burns from the bottom and the smoke generated by the burning fuel flows from the fuel-box 9, through an interconnecting duct 11 and into the first of said combustion chambers, while passing an intake for secondary air of combustion provided in the duct 11 connecting said chambers. The first combustion chamber 6 will thus function as an afterburner in the illustrated case, and therewith provide a "fireplace" in which slow-burning is obtained in a manner to produce an "open-fire" atmosphere. The combustion chambers 6 and 7 are preferably dimensioned to suit the size of^" the fire desired.

It will be understood that the aforedescribed stove may be modified in various respects. For instance, the heat reflector device 8 may be mounted on one edge thereof, so as to extend vertically, or substantially verti¬ cally, in the combustion chamber, and the flue gases may be caused to pass through flues, so as to heat the illustrated furnace lining 14. The lining 14 may also be heated directly, by heat reflection from the device or devices 8.

The combustion chambers 6 and 7 are mutually separated by a partition wall 15. The outer casing or jacket of the stove is made of metal sheet and the two front doors are made preferably of heat-resistant glass. The inventive solid-fuel burning stove constitutes a fur¬ ther development of the heat-reflecting principle and is a combination of three types of fuel burner, i.e. a boiler with slow combustion, such boilers normally being installed in a separate room, a conventional stove which has a conventional open-fire facility, or a facility whereby the fire can be contained behind clo¬ sed stove-doors, and a stove which has an afterburner facility.

When using the inventive stove, the fuel placed in the fuel-box 9 of the second combustion chambers will burn from the bottom over a period of from 4-8 hours, de- pending on the nature of the fuel concerned and on the quantity of fuel charged to the combustion chamber, and will in all events burn more slowly than the fuel charged to a conventional stove of this kind when all conditions are equal, without over ignition of the fuel, either in the one combustion chamber or in the other. Fuel combustion is primarily controlled in the said second combustion chamber 7, over a selected length of time and under controlled conditions. Fur¬ thermore, fuel-combustion is effected in the inventive stove in an "environmentally friendly" fashion, due to the reflection of heat by the reflectors 8 onto the stove-lining 14, i.e. because of the furnace-within-a- furnace construction of the stove.

Although the combustion chambers 6,7 of the illustrated embodiment have been shown to be located side-by-side as seen from the front of the stove, it .will be under¬ stood that the combustion chamber in which the fuel- store is placed and in which the fuel is burned at a slow rate is located behind the combustion chamber in which fuel is burned with a higher flame, i.e. a "cosier" flame, as seen from the front of the stove. Furthermore, in accordance with a further embodiment of the invention, not shown, the interconnecting duct 11 through which secondary air of combustion is introduced is incorporated in a separate stove-module which is fitted between the combustion chambers 6, 7 and which, particularly when the combustion chamber 7 containing the fuel store 9 is located behind the combustion cham¬ ber 6, extends over the whole width of the stove. The heat reflecting device or devices 8 may also be built- in the partition wall 15 dividing the two combustion chambers, instead of constituting a free-standing part.

It will also be understood that, although not shown, the outer casing or jacket of the inventive stove may be provided with means, e.g. a recess, for holding stones or like material which can be heated by the heat given-off by said casing, such as to produce steam when water is poured onto said stones, and therewith enable the stove to be used to produce steam in a steam sauna.

It will also be understood from the aforegoing that the first chamber 6 may be used solely to burn the gases of combustion generated in the second combustion chamber 7.

Claims

1. A stove intended for burning solid fuel and having an outer casing (14) provided with an openable and sealable front (1) and enclosing two mutually adjacent combustion chamber (6, 7) which are interconnected at their lower parts by means of a duct (11), charac¬ terized in that a first (7) of the two combustion cham- bers (6, 7) is constructed so that fuel will burn from the bottom and/or the sides thereof; in that the duct (11) is operative to conduct the gases of combustion in said first combustion chamber to the second (6) of said two combustion chambers (6, 7) ; in that said second combustion chamber (6) is intended to function as an afterburner in respect of gases of combustion generated in the first combustion chamber (7) and also as a fire¬ place for the combustion of solid fuel with a higher flame to provide an open-fire effect; and in that the stove is constructed so that fuel can be burned in either one of the two combustion chambers (6, 7) either separately or simultaneously.

2. A stove according to Claim 1, characterized in that the openable and sealable front (1) of the stove has the form of two glass doors (1)

3. A stove according to Claim 1 or Claim 2, charac¬ terized in that the duct (11) connecting the two com- bustion chambers (6, 7) incorporates an intake (12) for secondary air of combustion.

4. A stove according to any one of the preceding claims, characterized in that at least one of the com- bustion chambers has mounted therein a device (8) for reflecting the heat generated by fuel combustion onto the outer casing of the stove.