SE428601B - Fireplace Insert - Google Patents

Description

8001899-5 10 15 20 25 3G further improves efficiency. An effort of the take strokes is described in brochure number "Braselement" published by Villaprodukter AB, Box 7061. S-30007 Halmstad, Sweden, 1978.

However, stove inserts do not provide a solution to the main the problem with the fireplace, namely the one mentioned above negative heat economy at low outdoor temperatures - when the fire is_needed best. In unfortunate cases, rate to further aggravate the heat economy further brought with stove without insert. The hot air emission from the in- the kit is generally located near the fireplace the opening. Part of this often very hot air can drawn back to the fireplace and thereby further increase the draft through the chimney and thus also taken of cold air to the house compared to the case that the thief air through the chimney consists of room air of low temperature.

The primary object of the present invention is to provide an insert for fireplaces and similar fireplaces that allow a regulation of the supply of the combustion air to the fire and a reduction of the escape of stolen air through the chimney. Thus obtained good overall heat economy even at low outdoor temperatures instead of the negative heat economy imposed on spoken above.

The total efficiency can, thanks to the new Spis- the effort is improved to a level approaching the level for the modern wood stoves without any expensive conversions need to be resorted to.

It has also been shown that the new effort provides a line other benefits of a partly unexpected kind. That regulation of the combustion process provides an opportunity to extend the burning time for a given fuel charge may not be 10 15 20 25 30 8001800-5 unexpected benefit. Surprising, however, is that you thank whether the insert according to the invention can provide one such regulated combustion in a fireplace.

It is also completely unexpected and surprising that incineration takes place more environmentally friendly and completely than by a fire in a fireplace with a conventional stove effort. Emissions of unburned, tar-like substances saws, soot and ash with the flue gas can thereby be reduced a lot which is of extremely great importance in a situation where many households in .village communities and more or less densely populated areas are forced switch to wood burning due to the increased oil prices na. The improved combustion can be traced back to the special geometric conditions that characterize the construction and design of the new insert. Up- The invention also has a number of other benefits such as shall appear from the following description.

The invention thus consists of a new insert insert intended for fireplaces or other similar fireplaces burning with fuel in the form of firewood, briquettes, pellets or similar wherein the stove insert contains a four-chamber and an embers separated from a grate to which the embers res primary combustion air characterized by the boiler room inclined from its trailing edge to its leading edge and by the room is designed in such a way that the fuel on the the rust is enclosed by the boundary surfaces of the lighthouse whereby secondary air for the final combustion will be is applied to the open upper part of the boiler room via its upper edge.

The invention will now be described in more detail with the aid of the drawing.

Figure 1 shows the principle of the insert according to the invention. 80Û180U-5 l0 15 20 25 30 Figure 2 shows an embodiment with a built-in heat exchanger for delivery of hot air to the room. ' Figure 3 shows different profiles for the lighthouse, Figure 4 shows an installation of the insert in an open stove.

The insert according to the invention is preferably manufactured made of refractory sheet metal and can best be described as one box without lid, a lighthouse box, which is placed on the fire place.

The front of the drawer (1) faces the opening of the fireplace is lower than the back (2). Both sides of the box (3) therefore slopes towards the front of the lighthouse, See figure l. dan (2) can often consist of the inner wall surface of the fireplace.

The fuel consists of firewood, briquettes, rods of exe chipped pellets, pellets, etc. are arranged on the inclined rosette. (4) which ends at the bottom with a height (5) in order to the fuel from falling off. The space below] I the rust: (4) forms an ember (6). dimensioned to a normal fire consisting of e.g. The lighthouse box is like that 'Seven medium-sized firewoods largely fill the lighthouse (7) formed in the lighthouse box above the rGStën (4) - The front (l) is fitted with hatches or similar for supplying primary air to the annulus (6). Fi- Figure 1 shows simple rotatable doors (8) of the same type as occurs on tiled stoves etc. Such hatches can also be arranged on the outer sides (3) and possibly also on the back (2) for the supply of the primary air from the to the glow chamber (6). The invention is thus of course not limited to this specific design of the hatches. There is one in the prior art large number of suitable constructions for manual or automatic regulation of the supply of primary air such as simple adjustable doors, rosette valves, äUt0matiSkt 10 15 20 25 30 8001800-5 operating devices with bimetals or other sensors which controls the setting of the shutter or shutters.

A particularly suitable embodiment in this context is to make the entire front (l) in the form of a sliding door in tempered glass that can be pushed up into its frame so that a gap is formed at the bottom for the supply of market air. This particular embodiment also provides one better emission of radiant heat from the lighthouse to the room and a significant well-being value because the whole fire can be viewed from the room.

The technical effect of the invention depends on several cooperating factors constructive grips: The design of the lighthouse which includes and contains the fire closes so that secondary air for the final combustion is added to the open upper part of the lighthouse via its upper side.

The sloping rust which results in a successive trans- port of the fuel towards the front of the lighthouse whereby the top of the fire will mainly lean towards the fireplace opening.

The regulated supply of primary air to the incandescent the room that provides a preheating of nri¶ärluf * _ and a final combustion of the embers, which gives heat for the pyrolysis and gasification reactions in the fuel resting on the rust.

These as it may seem simple constructive measures provide primarily the unexpected effect of the departure of theft air to the flue is greatly reduced. It is difficult to fully explain this technical effect but a significant one contributing factor is probably the different flow conditions the conditions of the operation according to the invention compared with a fireplace without insert or a fireplace with insert aoo1seo-s 10 15 20 25 30 0 '\ rates according to current technology. The supply of primary air via the tailgates (8) or equivalent devices also affects the supply of secondary air for final burning over the upper edge of the lighthouse into the fire. One the closest laminar flow of combustion gases takes place from the firebox up to the smoke bag and the smoke passage in the fire the city. It is surprising that this control of secondary the air is produced without special devices otherwise than the geometric design of the lighthouse box, its filling with fuel charge and the tailgates for pri- At flat surfaces in the fireplace, the bottom box of the lighthouse can and the back consists of the fireplace wall resp. the hob.

The slope of the fuel bed provides a certain amount of current flow during combustion that seems to contribute to it -efficient combustioneQ_ The most intense ember combustion- one occurs at the front of the fuel charge where they are hot the gases to some extent move in the bed towards its back.

The fresh. often the raw fuel is replenished at the top so that the fuel is dried, prepyrolized, pyrolysed, gasified and final combustion successively during the movement from the back of the lighthouse towards its front. The gases emitted goes at the back mixed with very hot combustion gas and combustion air, which provides efficient burning of these gases that would otherwise occur some go unburned out through the chimney.

It should also be added that the slope of the bed does that more radiant heat is emitted to the room and that even a_ fire with a smaller number of firewood gives the same well-being and feeling warm like a conventional fire with more wood.

The seemingly simple and unsolicited design of the new the stove insert thus provides a series of unexpected partial different, partly coherent technical effects as all collaborates to a surprising overall result that expresses 10 l5 25 30 soo1eoo-s \ significantly lower fuel consumption and better control combustion in a simply supplemented fireplace.

Figure 2 shows a special embodiment where the lighthouse in its designed as a heat exchanger for the supply of heat air to the room. For simplicity, the grate (4) is not displayed.

The circulating air is taken in via an inlet (9) and supplied with by means of the fan (10) via the inlet duct (ll) to the the bottom (12) of the box which, like the other interfaces consist of heat-exchanging elements, columns or channels. In the design according to Figure 2, adds the now heated air from the bottom of the lighthouse (l2) the back of the lighthouse (13) where further heating takes place after which the hot air flow is distributed between the two the side walls (14) resp. (15) which will at the outset be the race channels (16) resp. (l7). The two outlet channels The ladders are advantageously provided with the dampers (19) resp. (20) so that the air can be distributed between the two outlets in a desired way, the back can advantageously be extended upwards so that as much as possible is utilized by the fireplace heat.

Temperature sensor (Zl) resp. (22) may also be provided those in the outlets for controlling the speed of the fan so that it the outgoing air in one of the two ducts does not a set maximum temperature rises, for example 70 ° C.

(Preheated air can also be diverted to the glow chamber from the outlet.) The stove insert according to Figure 2 is also provided with a front side consisting of a sliding glass door (23) which N n 1.. af r fl ralst arranged 1 Spalterna (24) and which can be slid up or down with the help of the rotatable eccentric Vßr fl ä (25) which is operated with the rods (26) with the knobs (27) arranged next to the outlet ducts.

Of course, there are many other opportunities to join Using known structural elements and structural 8001890-5 10 15 20 25 30 principles from this area take advantage of a larger or smaller part of the heating effect of the fire in the form of hot air for delivery to the house, from simple arrangements with self-circulation to more complex complete systems systems with hot air lines with special thermostat control safety damper, hot air drain for use as preheated primary air, etc.

The stove insert should be designed so that the rust takes up a angle in the range 5-450, preferably 10-300, for to provide a suitable fuel passage along the grate and the "favorable pattern of gas flow" with one element of countercurrent flow between fuel charge and gas. The part of the lighthouse that lies above the sloping rust plane has a height, h, exceeding at least about 1/10 of the width the one in the lighthouse so that at least one layer of firewood etc. are enclosed within the confinement surfaces of the lighthouse; Figure 3 shows examples of suitable profiles for the teeth rust. Figure 3a shows an adjustable rust that can take different angles of inclination in relation to the the number plane. The support rod (28) is hinged at (29) and (30) and can be fixed to the hooks (31). The rust is a unit in itself.

Figure 3b shows a profile where the height, h, is above the rust plane increases towards the back of the lighthouse to compensate for it volume reduction that the fuel undergoes during combustion and the transport towards the front edge of the lighthouse. This r0St forms part of the lighthouse box and is built together with it.

Figure 3c shows a profile characterized by the angle ”Towards the horizontal plane decreases from the back of the lighthouse towards its front so that the angle at the front in the nearest tea coincides with the horizontal plane. This profile is often preferable to a constant angle of inclination for the whole rust because it gives a more even distribution of the ember layer in the ember space. This rust is a separate unit placed in the lighthouse box. 10 20 25 8-001800-5 .It is often practical, as in Fig. 2, to have the front (1) is made of a sliding door of tempered glass that sticks out up above the lighthouse to serve as spark arrestors. The is of course also possible to use a spark arrestor consisting of a net or a perforated sheet make part of the stove insert. The front edge of the lighthouse counts here at the level of the external connection to the front the side whereby the excess portion of the front serves as spark arrestor.

The technical effect of the invention does not change significantly if the front of the lighthouse is mounted so that it simultaneously serves as a spark arrestor according to figure 2. The transport of secondary air to the open top of the lighthouse above the lighthouse the leading edge of the box is admittedly deteriorated but compensated increased transport of secondary air at the outer surface nas front edge. A dedicated front page can also do something improve the laminar flow pattern for flue gas the hallway from the sloping lighthouse.

Figure 4 shows an insert (32 according to figure 1 arranged in a fireplace C39 near the smoke passage (39 provided with the smoke bag (39, the damper (35) and the heat exchanger (37). the city is complemented by glass doors (38). spjäiiet (36, can be set in different positions using the damper roof (33) and the pins (4Q). This opportunity to set the damper in different positions according to the supply of primary air to the stove insert of course provides opportunities to further limit the theft air gap when using the stove insert according to the invention.

A certain freedom also exists in the dimensioning of the lighthouse especially its lighthouse. The essential is know that the lighthouse leans towards the front edge of the lighthouse and that the walls are raised so that the fuel charge contains 8001800-5 10 15 20 25 30 .l0 ends in the lighthouse under an imaginary lid that is imagined rest on the upper edge of the lighthouse.

The width of the lighthouse is suitably made slightly larger than the length of the firewood, briquettes, etc. to be fired in the effort. A width of 30 cm or slightly more is suitable for the smallest dimension of firewood. Larger fireplaces can be fired with advantage with firewood of roundwood of e.g. deciduous trees as in that case with advantage can be for example 50-60 cm long. The is an advantage for those who can harvest thinning timber on own land to fire with round timber of reasonably large length.f The transport of the fuel towards the lower part of the grate also goes easier with round timber compared to split _ firewood.

The depth of the lighthouse box, axis is equal to the length of the outer sides, can be within certain limits. It is often appropriate to use a square cross section so that the depth of the lighthouse becomes equal to its width. less than half the width and does not exceed twice the width to contain the features of the invention However, the depth should not like drawing the flow conditions.

The slope of the lighthouse is achieved primarily through that the rust is inclined towards the horizontal plane as shown in Figure 3. The average angle of inclination should be rise about 5 ~ °. A particularly suitable value is range 13-300 but also higher angles of inclination are reversible, up to 45 ° or slightly above.

The upper edge of the lighthouse should largely follow the rust slope, although it may be advantageous to increase the it (h) at the rear of the lighthouse as shown in Figure 3b.

The height (h) should exceed at least one tenth of the width in the boiler room to make room for at least one warehouse lO 15 20 25 30 8001800-5 ll of firewood. However, it may be appropriate to dimension the height (h) to 2 ä 3 tenths of the width of the lighthouse to make room for several layers of firewood. The height should however, do not exceed about half the width of the lighthouse to also allow efficient final combustion of fuel the charge under the advantages of the invention the same conditions.

The dimensioning of the ember is of less importance for the technical effect of the cooker insert. The glow should, however given such a height at the leading edge that sufficient space is formed for embers and ashes from at least two or three refuelings, thereby allowing passage of the primary air over the ember layer. An often appropriate value of the height at the leading edge of the ember is between 5-10 cm.

The insert is suitably made of welded steel sheet, for example. pelvis with a thickness of 4 mm. When the walls are made double- la to simultaneously serve as a heat exchanger for delivery of hot air in the room, you can use rectangular steel pipes or elements that are welded together, for example according to the figure 2. It is important to check that such heat elements are completely dense and they should therefore tried at 2 atö.

The rust is suitably made of rods, flat iron, or other suitable profiles preferably in refractory steel. Out- the formation of the rust of course depends on what kind fuel stove insert is intended for. If the fuel was firewood, roundwood, briquettes, etc. can be na between the rust rods are made relatively wide, from some or a few cm all the way up to five cm or something over it. If the firing is intended to take place with pellets, ie compacted wood chips, peat, or similar shells eou1snn-5 10 15 20 30 12 the grate must be so designed that the pellets are retained on the until they have turned into embers. In such cases, the grate consists of a perforated refractory sheet or a deaf. of so-called expanded metal etc. Pellets occur in different dimensions with diameters from only a few mm up to several centimeters. The openings in a rust seen for pellets should be less than the pellet dimensions in at least to an extent. An appropriate value for the smallest dimension pellets is a maximum extent for the openings of a few mm while a largest extent of 5-10 mm is suitable for large pellets.

A cooker insert made according to figure 2 - and inserted in one fireplace according to figure- 4 was charged with a normal fire consisting of 7 medium-sized firewood with a total weight of 2 l / 2 kg. that the fire burned down in 4 hours, the average The heat effect to the room was about l kW corresponding to an efficiency of close to 50%. At The primary air supply was regulated in this way combustion of the same fuel charge directly in the open then the fire burned down in two hours and delivered heat mainly in the form of radiant heat corresponding about 200 W.

The total departure to the surroundings via the chimney amounted to close to 2000 m3 of warm room air at it conventional fire while the corresponding value for it total gas emissions, compressed air plus flue gases, went to about 400 m3 when firing with the stove insert.

The deposits of soot and so-called creosote in the flue became significantly less when firing with the insert compared with the conventional fire. The final combustion in the flame zone formed above the fuel charge fl çedde very evenly, efficiently and completely which made himself known through very little smoke formation. 8001800-5 13 The description takes note of the special characteristics for the stove insert according to the invention. Some pre- drawn embodiments have also been specified to give the person skilled in the art guidance in the application of the invention ningen. The object of the invention is thus not limited to the special embodiments mentioned in the previous description.

Claims (1)

søoesnn-5 10 15 20 25 ..-__ i, ____.....-........._., ._._'_..__, ...__. Requirement 1 Stove insert intended for fireplaces or other similar fireplaces for burning with fuel in the form of firewood, briquettes, pellets or similar solid fuels, the stove insert containing a boiler room (7) which slopes from its rear side (2) towards its front side (1 ) and a glow chamber (6) separated by a grate (4), to which glow chamber (6) is supplied primary combustion air, characterized in that the boiler room (7) is designed so that the fuel is enclosed by the limiting surfaces of the boiler room so that secondary air for the final combustion upper part via its upper side. Claim 2 Stove insert according to claim 1, characterized in that the bottom (12) and walls (13, 14 and 15) of the stove insert are designed as heat exchangers for heating room air. Claim 3 Stove insert according to claim 1, characterized in that the front side (1) consists of a sliding door (23) of tempered glass. Claim 4 Stove insert according to claim 1, characterized in that the average slope of the grate (4) is 10-300 in relation to the horizontal plane.