Device for exhausting the fumes forming inside accumulator batteries

Abstract: The invention discloses a device for the exhaust of the fumes forming inside accumulators, which comprises a chamber (7), obtained in the lid (2) of the accumulator, communicating with the exhaust ducts (4) which connect with one another the accumulator re-fill openings (3), an anti-explosion paste (11) being lodged in said chamber (7) and being kept in position by the adherence of a removable cap (12) provided with a through-going central opening (14). In its intermediate position said chamber presents a shoulder (10) against which the anti-explosion paste (11) rests flush and which defines between said paste (11) and the bottom (8) of said chamber (7), a pre-chamber (18) having the task of collecting the condensed electrolyte vapors, said pre-chamber communicating with the underlying elements of the accumulator through at least one through-going hole (20).

Description: The invention concerns an accumulator lid having a device for exhausting the fumes forming inside accumulator batteries. It is a known fact that, particularly in lead accumulator batteries, during their working stage and/or during the recharging stage, fumes form which must be exhausted since, if that is not done, they would cause an inflating of the accumulator with the consequent possible breakage of the same. For this reason the lids are provided with exhaust ducts which connect with one another the refill openings of the accumulator lid and connect them to the exterior through outlet openings. In one or more of said outlet openings a connection complete with a hose is provided for the conveyance of the fumes to the exterior. Since the fumes forming inside the accumulator also contain highly explosive hydrogen, in some cases it is necessary to also apply an anti-explosion device which, should flames or sparkles be present in the room around the accumulator, has the purpose of preventing the flames or the sparkles from entering into the accumulator through the exhaust ducts and causing the explosion by igniting the fumes which are present within the exhaust ducts of the lid. Said antiexplosion device consists of a disc comprised in the state of the art technique which is made of a material allowing the fumes inside the accumulator to be exhausted, but preventing the entrance into the exhaust ducts of the lid of incidental flames and sparks, which would cause its explosion. In some constructions this anti-explosion disc is held in a container which is an integral part of the joint applied in the opening of the exhaust duct. In particular, said disc is arranged between the union connecting the joint with the outlet opening of the exhaust duct and the hose conveying the fumes away from the accumulator. On the other hand, in some other embodiments comprised in the state of the art, the anti-explosion disc is part of the lid of the accumulator and it is positioned within a chamber near the outlet opening of the exhaust ducts. The patent document WO-A-8604186 discloses a lid for accumulators in which are present channels for conveying gas with an hopper having a gas permeable disc disposed substantially horizzontally and, consequently, invested directly by all gas going out of the accumulator. In both types of embodiment there is the inconvenience that, since the anti-explosion disc is permeable to fumes but not to liquids, it clogs up whenever the condensation resulting from the electrolyte liquid, which is led into the fume-exhaust ducts in the vapor state, comes to rest on the point of connection of the disc. It is easy to understand how such an occurrence can cause remarkable inconveniences and also dangers, since, if this occurs, the fumes are not let out and they build up inside the accumulator. This entails, as has already been said, the inflating of the accumulator and its ensuing deformation. In order to avoid this inconvenience, the device according to the present invention has the main purpose of warranting the constant exhaust of the fumes from the interior of the accumulator, even in the case of condensation on the anti-explosion disc of the vaporized electrolyte, which has found its way into the fume exhaust ducts, during the evacuation phase to the exterior. The described purpose is reached by providing a lid for an accumulator having an exhaust of the fumes forming inside the accumulator with the main features thereof as indicated in the preamble of claim 1, the essential inventive features of said lid being as defined in the characterizing part of claim 1. According to a preferred embodiment, the chamber containing the anti-explosion disc has a cylindrical shape and it is provided in the vertical wall of the peripheral rim of the lid, in correspondence with the outlet opening of each exhaust duct. In one example of embodiment of the invention, the removable cap pushes the anti-explosion disc flush against the shoulder and it is inserted in the cylindrical chamber with an interference, so as to achieve, in correspondence with the lateral surface of mutual contact, the tightness with the cylindrical chamber. The anti-explosion disc also achieves the tightness with its lateral surface, which interferes with the inner lateral surface of the cylindrical chamber containing it. In another embodiment of the invention the cap is provided with an annular recess lodging the anti-explosion disc. Advantageously, in the case of condensation of the electrolyte forming on the anti-explosion disc, the device according to the invention insures both the backflow of the condensed electrolyte into the accumulator, and the continued discharge of the exhaust fumes. The possibility for the anti-explosion disc to clog is, therefore, eliminated, while, at the same time, the efficiency of the fume-exhaust system is guaranteed. Moreover, the device according to the invention also advantageously prevents the electrolyte from dripping out of the accumulator. Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, wherein: Fig. 1 is a top view of an accumulator lid to which the device for the fume exhaust according to the invention has been applied; Fig. 2 is the magnified view of a vertical section made in the lid in correspondence with an exhaust duct in which the exhaust device according to the invention has been applied; Fig. 3 shows in a cross-section a different embodiment of the fume-exhaust device according to the invention. As can be observed in Fig. 1, the exhaust device according to the invention, indicated as a whole with 1, is applied on an accumulator lid, indicated as a whole with 2, which presents a plurality of re-fill openings 3, which are connected to one another through a plurality of exhaust ducts 4, which, as can be observed in Fig. 2, have been obtained in the upper wall 5 of the accumulator lid 2, near its inner surface 23 facing the interior of the accumulator. In correspondence with the lateral wall 21 of lid 2, at the spot where said ducts 4 communicate with the outside environment, there is, as can be seen in Fig. 2, a cylindrical chamber 7, the bottom 8 of which communicates through a hole 9, with one of the exhaust ducts 4, while its lateral inner surface presents in an intermediate position a shoulder 10. Against this shoulder 10 the anti-explosion disc 11 is pushed flush by the pressure of the annular rim 13 of cap 12 inserted in the cylindrical chamber 7. Said cap 12 presents also an interference with the cylindrical chamber 7 wherein it is inserted in correspondence with the lateral walls 24 in mutual contact with each other and, as a consequence, cap 12 is tightly connected with the cylindrical chamber 7. Said interference between cap 12 and the cylindrical chamber 7 holds disc 11 within the cylindrical chamber with a force which counteracts the inner pressure produced by the fumes forming inside the accumulator. By suitably adjusting the value of said interference, it is possible to pre-set the maximum pressure threshold, beyond which disc 11 and cap 12 are pushed out of cylindrical chamber 7, so that the device according to the invention also acquires the characteristics of a safety valve. Moreover, the anti-explosion disc 11, in correspondence with its lateral surface 22 is also tightly inserted into said cylindrical chamber 7. The middle of cap 12 presents an opening 14, into which a joint (not represented in the drawing) with a hose is inserted. This has the task of conveying the fumes out of the accumulator. In fact, through the re-fill openings 3, which are shut by the caps 15, the fumes forming inside the cells of the accumulator are conveyed following direction 16 into the exhaust ducts 4 and from here, going through hole 9 and the anti-explosion disc 11, they are conveyed outside. During said fume exhaust, part of the electrolyte turns into vapor and is entrained by the fumes, following direction 16, along the exhaust ducts 4, until it reaches the anti-explosion disc 11, where it stops and condenses. This is the reason why the described shoulder 10, againts which disc (11) is placed, has been made in the cylindrical chamber 7; so that surface 20 of disc 11 and bottom 8 of the cylindrical chamber 7 define a pre-chamber 18 which collects the condensing electrolyte vapor, which then falls back down, following direction 19, into one or more accumulator cells going through hole 17. Hence there is no chance of liquid building up close to the anti-explosion disc 11, which can continue its fume-exhausting activity, keeping its efficiency unchanged in time, thus reaching the purpose proposed by the invention. The dripping of electrolyte in the outside environment is also prevented. Also, should there be an overpressure build-up, when the same exceeds the value of the interference of cap 12 in chamber 7, cap 12 and disc 11 are pushed out of chamber 7, so that the exhaust device also acts as a safety valve. Fig. 3 shows a different embodiment of the invention. This embodiment varies from the previously described one, in that the anti-explosion disc 30 is lodged in the annular recess of cap 31, positioned at the end of the exhaust duct 32 of the lid 40. In this case, too, there is a pre-chamber 33 which collects the condensed electrolyte vapor and presents a hole 34 at its bottom, having the purpose of discharging the electrolyte which has condensed in the pre-chamber. One or more of the described devices can be applied on the accumulator lid, i.e. it will be possible to realize in correspondence with each exhaust duct a cylindrical chamber suited to lodge an anti-explosion disc or, should the exhaust duct be central, as described in the Italian patent application No. VI91A000089, the device will be single and it will be applied in the single central duct. During the manufacturing stage the device according to the invention may undergo changes and modifications having the purpose of improving its efficiency and to make its manufacture easier. Said changes and modifications will, however, not exceed the scope protected by the present invention.

Claims: An accumulator lid (2) comprising: a plurality of re-fill openings (3), connected to one another through a plurality of exhaust ducts (4,32); a lateral chamber (7), in correspondence with a lateral wall (21) of the accumulator lid (2) communicating on one side with at least one exhaust duct (4,32) and, on the opposite side, communicating with the outside environment; an anti-explosion disc (11,30) placed within said chamber (7) in substantially vertical position; a removable cap (12,31) presenting a central through-going opening (14), inserted in the chamber (7) and adhering against the anti-explosion disc, characterized in that said chamber (7) presents a pre-chamber (18) defined between the side of said lateral chamber (7) communicating with said at least one exhaust duct and the surface of the anti-explosion disc (11,30), said pre-chamber (18) collecting the condensed electrolyte through a through-going hole (17,34) into the underlying accumulator cells. A device according to claim 1, characterized in that the removable cap (12) is inserted in chamber (7) with a junction which interferes in correspondence with the lateral surfaces in mutual contact between said cap (12) and said chamber (7). A device according to claim 1, characterized in that the anti-explosion disc (11) is comprised between a shoulder (10), which is present in the chamber (7), and the cap (12). A device according to claim 1, characterized in that the anti-explosion disc (30) is inserted through pressure into a cylindrical recess of the cap (31). A device according to claim 4, characterized in that the chamber (7) is placed centrally in the lateral wall (21) of the lid (2).

Inventors: STOCCHIERO OLIMPIO, STOCCHIERO, OLIMPIO
Applicants: STOCCHIERO OLIMPIO, STOCCHIERO, OLIMPIO
Application year: 1992
Main classification: H01M2
IPC codes: H01M2