GB2501114A - Stove with smoke and heat capturing water sprays - Google Patents

Abstract

A solid-fuel fired stove has an enclosed tank 2 for holding water, with two tubes 3,6 extended upwards from the top of the tank, each tube having a nozzle 5,7 to spray water down the tube onto smoke particles and into the tank, one tube 3 receiving combustion products from a firebox 1, and the second tube 6 open to the atmosphere via duct 8. The sprays 5,7 work in opposite directions which is said to reduce the pressure change and maintain draw on the fire. A heat exchanger 11 or conductive pipe portion cools the water, a pump 9 circulates water, and a pipe 10 discharges scum from the tank 2. The stove can operate without a chimney.

Description

TITLE: Smoke-Reducing Condensing Stove With Heat Recovery INVENTOR: Glyn Hughes

BACKGROUND:

Stoves burning solid fuels such as wood or coal account for much of the world's domestic heating. They are reliable and moderately efficient, but will only operate effectively when heat is lost into an attached chimney in order to generate draught, and they often emit highly deleterious smoke particles into the atmosphere.

The present invention discloses a type of solid-fuel stove which can operate without a chimney, which collects and can safely dispose of smoke particles and which can useftilly rccovcr almost all the heat relcased by combustion.

This is achieved by the stove including a scrubbing tube' in which water is sprayed down a tube to precipitate smoke particles, to generate a draught to engender combustion and to capture heat. While this type of'scrubbing tube' is not new, it has previously been found impossible to apply to small stovcs as the high velocity of water necessary to knock out' smoke particles generates too high pressure for a domestic stove to work safely or effectively.

In this invention there are two scrubber tubes in the stove, each working in opposite directions relative to the gas flow, which means that the down' pressure generated by one tube is partly canccfled out by the up' pressure of the other, so that the net negative pressure apphed to the ftiel-filled firebox can be ananged to be at a level suitable for domestic combustion, while at the same time having the scrubbing effect of not one but two high-velocity water-blasts.

It is found that almost all of the residual heat from combustion can be absorbed by the scrubbing spray. The invention requires that a heat-exchanger be incorporated in ductwork of the water circuit to recover this heat.

DISCLOSURE:

The invention is a solid-flwl fired stove.

An embodiment of the invention is now disclosed in figures 1 and 2, where figure 1 is a schematic diagram and figure 2 represents the rear view of one possible practical construction, partly cut-away. In these figures a stove comprises a firebox (1) in which fuel is burned, a tank (2) partly filled with water, a tube (3) extending from the face of the tank to a port (4) from which the gaseous combustion products and smoke are discharged into the tube and a spray head (5) by means of which water can be sprayed down the tube. A second tube (6), also extends from the face of the tank, and also has a spray head (7) by means of which water can be sprayed down the tube, and which tube has access to a duct (8) delivering gases to the atmosphere. A pump (9) circulates watcr from the tank (2) to the spray-heads (5 and 7).

A discharge tube (10) is provided adjacent to the surface level of the water surface in the tank (2) The operation of the invention is as follows: The spray of liquid from the spray-head (5) causes a reduction in pressure inside the tube (3), causing the gaseous products of combustion and the smoke emitted by the burning fuel in (1) to be drawn along the duct (4) and into the tube (3) where the liquid spray causes smoke partidcs to be precipitated into the water in the tank at (2), where they are found to form a scum on the surface. The shape of the second tube (6) and its fittings is so arranged that the spray down it from spray-head 5) does not generate a net reduction in pressure greater than that created in the first tube (6). Remaining flue gases and smoke particles are thus carried through the space above the water in the tank up the second tube where there is ñrther opportunity for any remaining smoke particles to be precipitated into the water tank, before the remaining flue gas is discharged to the atmosphere through the duct (8). The circulation of water forms a closed system in the invention, apart from the liquid lost along with the smoke-scum. The circulating water is found to collect much of the remaining heat, which heat is then recovered by means of a heat exchanger (11).

A discharge pipe (10), leading out from the water tank, is situated just below the normal surface level of the water so that the smoke-laden scum is discharged from the tank while the water level is replenished by a system which is not part of this invention.

Claims (2)

1. CLAIMS: The invention in which an exclusive property and privilege is claimed is defined as follows: 1. A solid-friel fired stove comprising an enclosed tank capable of holding water, a face of which tank is in two places extended upwards so as to form two separate tubes, each tube having at its summit and within it a spray nozzle from which water can be sprayed down the tube and into the enclosed tank, and an opening in one of the tubes which connects to a duct leading to an enclosed chamber in which fuel can be burned, and an opening in the second tube which opens to a duct leading to the atmosphere, and a pump whereby water can be circulated from the enclosed tank to the spray nozzles by means of a duct, a portion of which duct is constructed of a conductive material such that heat in the water inside of the duct can be transferred to the outside of thc duct.
2. 2. An invention as described in claim (1) with a further opening in the enclosed water tank leading to a discharge duct at a point below the surface level of water in the tank.