EP0733856A2 - Rotary feeder for solid fuel - Google Patents

Abstract

The solid fuel feeder for a stove, wood-burning heater or fireplace, consists of a rotary loader with a series of radial vanes (2) projecting from a central axle and rotating inside a fixed cylinder (3). The vanes form a series of compartments which are filled with fuel and equipped with trap doors (5) which open to release then fuel into the combustion chamber as the loader rotates. In a variant of the design the vanes can be located between two coaxial cylinders, the inner one of which forms the combustion chamber and is covered by a grate to which the fuel is delivered as the loader rotates.

Description

The subject of the present invention is the rotary feed device for solid fuels, particularly suitable for stoves, boilers, fireplaces or cookers, which is defined in claim 1.

The originality of the device lies in the fact that it has a fixed cylinder with a horizontal axis, and a rotary charger with radial sectors which is housed inside the cylinder and which, containing solid fuels such as wood, coal , briquettes or the like, turns around the axis of the aforementioned cylinder.

The movement of the rotary loader can be automatic or manual.

In the case of automatic operation, the mechanism can be controlled either by an electrical or electronic control unit which, in turn, receives a signal from sensors which read the temperature of the fumes or water from the boiler, or more simply by means of a programmer timer.

It is known that the combustion chambers of all the aforementioned devices, that is to say stoves, boilers, fireplaces or stoves, are equipped with a door for loading fuel, generally wood, but also coal or other type of fuel which necessarily requires continuous, constant manual recharging to maintain the temperature in the combustion chamber.

The object of the device according to the invention is to avoid having to continuously load fuel, with obvious advantages both in terms of saving time and fatigue, autonomy, efficiency, cleanliness, pollution, as well as the operation and duration of the generator.

Other advantages that come from continuous feed automatic loading are:

a) Elimination of the problem of condensation of combustion fumes both in the hearth and in the conduits through which the outlet fumes pass. Indeed, it is known that, frequently, to obtain greater autonomy, the user is required to completely fill the combustion chamber. The operation, although it is convenient, brings serious drawbacks to combustion.

Indeed, the distillation of wood due to the partial and slow combustion of the loaded mass leads to the deposit of tarry unburnt on the walls of the generator and on the walls of the outlet tube, with the consequent cleaning costs and a reduction in yield.

b) Pollution : it is also known that the combustion of solids develops in several phases and that the so-called "tail" phases reach significant pollution peaks.

We also know that the initial smoke emissions, in addition to being annoying, are also signals indicative of poor performance and high pollution.

The device according to the invention makes it possible to carry out a continuous and constant metering of the fuel before the combustion succeeds in completely consuming the embers, that is to say, it makes it possible to obtain a constantly optimal combustion curve, thereby excluding the phases constituted by the more polluting "tails".

c) Yields : the yields of wood boilers vary within very wide limits. Practice shows that an apparatus with manual loading is characterized on average by efficiency values which go up to 30% less compared to an analogous apparatus but with automatic loading.

The present invention therefore increases the efficiency in the sense that it perfectly maintains the combustion parameters, by constantly supplying the right quantity of charge to the combustion chamber.

d) Autonomy : frequently, the user, driven by convenience, is inclined to exclude the use of solid fuels. It is precisely the need to charge the combustion chamber every two or three hours which creates significant disadvantages for the user, who is frequently engaged in work outside the home.

The device according to the invention, which produces an apparatus capable of ensuring a fuel supply for up to 24 hours, completely automatic and free of manual assistance is therefore extremely advantageous and useful.

The supply device according to the invention can be produced in two different forms, both of which have the same operating principle:

1) Version with charger at the top, above the chamber combustion.

2) Version with charger at the bottom, under the combustion chamber.

• la figure 1 est une vue en élevation d'une chaudière à inversion de flamme équipée d'un dispositif d'alimentation selon l'invention ;
• la figure 2 est la vue de côté correspondante.
• la figure 3 montre le dispositif à échelle agrandie à l'état isolé ;
• la figure 4 illustre en élevation une deuxième forme possible de réalisation d'un poêle muni d'un dispositif selon l'invention ;
• la figure 5 est la vue de côté correspondante.
• la figure 6 représente le dispositif selon les figures 4 et 5, à échelle agrandie et à l'état isolé.

In the accompanying drawings:

• Figure 1 is an elevational view of a flame inversion boiler equipped with a supply device according to the invention;
• Figure 2 is the corresponding side view.
• FIG. 3 shows the device on an enlarged scale in the isolated state;
• Figure 4 illustrates in elevation a second possible embodiment of a stove provided with a device according to the invention;
• Figure 5 is the corresponding side view.
• FIG. 6 represents the device according to FIGS. 4 and 5, on an enlarged scale and in the isolated state.

In the first embodiment of the device according to the invention, which is shown in Figures 1 and 2, the storage of fuel occurs frontally, through the loading door 1, which is provided with a security system which fact that when the door is open, it is not possible for the mechanism to move.

The automatic loading of fuel into the combustion chamber takes place by a controlled rotation "step by step" of the radial sector loader 2, which rotates in the fixed cylinder 3.

This sector loader 2 contains and drives the fuel reserve in a rotational movement and, at each step of the rotational movement, it discharges by gravity the contents of a single compartment in the combustion chamber 4, in the sense that the hatch 5 which closes the compartment tilts down by gravity, because it can rotate around an axis 6.

In the case of automatic (not manual) operation, the "step-by-step" cycle which is established is as follows: after the first ignition and the subsequent heating of the combustion chamber, a sensor is provided to detect the lowering of the temperature following the exhaustion of combustion.

This signal sets in motion an electric motor 7 equipped with a geared motor, to impart a partial rotation to the mobile charger, rotation which is stopped by an end-of-travel device suitably mounted, until the sector has discharged the combustible.

Resumption of combustion, subsequent rise in temperature and subsequent cooling allow the cycle to continue. Everything will stop definitively when, under the effect of the total exhaustion of the stored charge, there is a final cooling of the combustion chamber.

The electric motor 7, mounted on the rear part of the device, is controlled by a control panel, not shown, which receives and processes the pulses coming from the temperature probes.

In the embodiment of the device according to the invention which is shown in Figures 4, 5 and 6, there is provided a construction configuration designed to be applied to stoves, boilers, fireplaces and stoves.

In this embodiment, two coaxial fixed steel cylinders 8 and 9 are provided, with a horizontal axis, while inside these cylinders, a rotor having compartments 10 rotates.

The fixed cylinders 8 and 9 have, in the upper part, a missing surface part or opening to make room for the combustion chamber 11.

Inside the cylinder 8, are housed both the lower grate 12 of the combustion chamber, which allows the arrival of air, and the ash drawer 13. The solid fuel is loaded from the front side, at through the open base of the two cylinders 8 and 9.

The compartment rotor 10 consists of a circular crown concentric with the fixed cylinders 8 and 9, with partitions 10 welded perpendicularly and arranged radially with respect to the axis of rotation.

The movement of the mechanism is generated by an electric motor 14, equipped with a device capable of reducing the number of revolutions, so as to produce a rotational speed suitable for the intended application.

This motor is advantageously mounted on the rear part of the boiler or of the stove 15 and is controlled by a control panel, not shown, which receives and processes the pulses coming from the temperature probes.

Claims (3)

Device for supplying solid fuels to stoves, wood boilers and fireplaces, both of the type with top loading and bottom combustion chamber as with bottom loading and top combustion chamber, characterized in that '' It comprises a rotary charger, produced using radial walls (2) which project on a central axis, said charger rotating inside a fixed cylinder (3), at the end of the combustion of the combustible material contained therein. Device according to claim 1, characterized in that the rotary loader comprises, in addition to the radial walls (2), closing flaps (5) which rotate around an axis (6), being provided that at each combustion phase, the flap (5) tilts down, letting the fuel fall into the combustion chamber (4), in the case of reverse flame or natural flame combustion. Device according to claim 1, characterized in that it comprises two coaxial fixed cylinders (8 and 9) inside which rotates a rotor with compartments (10), openings being provided in said cylindrical (8 and 9), of so as to produce a combustion chamber (11) closed at the bottom by a grate (12) and equipped with an ash drawer (13).

Images