Dust abatement device

Abstract

An abatement device (1), intended for the tanning industry, comprising a support structure (2) and a containment chamber (5) that receives an air flow via an intake duct (7). The air passes through a helical duct (10) around a central duct (11), separating the dust particles centrifugally. The dust falls into the collection means (14), while the filtered air is conveyed through a connecting duct (15) into a tank (16) containing a sanitising liquid (17), which captures further impurities. The purified air then passes into an expulsion duct (19), which is regulated by a damper (34) with a baffle (35), before being reintroduced into the environment. The abatement device (1) is equipped with ventilation means (8) that force air flow through the ducts, ensuring effective purification.

Description

[0001] DUST ABATEMENT DEVICE

[0002] DESCRIPTION

[0003] Field of application

[0004] The present invention relates to an improved dust abatement device intended to be advantageously used in any industrial field for purifying air from suspended particulate matter.

[0005] In particular, the abatement device in question is suitable for use in industrial deburring and polishing processes, in industrial leather tanning processes and particularly in shaving processes, in the woodworking industry, in the mechanical industry, in the metallurgical field, or, more generally, in any industrial process that involves the production of dust or solid particles destined to remain suspended in the air.

[0006] The purpose of the abatement device of the present invention is particularly to limit the dispersion of particles produced by production facilities into the environment in order to ensure safer working conditions for employees.

[0007] State of the art

[0008] Nowadays, as is well known, there are many commercially available devices for collecting particles resulting from production and remained suspended in the air inside the workplaces. This equipment, although generally optimised according to the specific application of the industrial sector in which it is called upon to operate, requires the use of ventilation means capable of sucking in a significant flow of air to be purified inside a containment chamber, where dust abatement takes place, and expelling the same purified air flow back to the external environment.

[0009] The principles on which the various dust abatement systems are based are basically: washing the air flow by sprays or waterfalls; filtering the air flow by means of filtering septa, bag filters, etc.; the creation of vortices or cyclones to centrifugally separate the dust particles contained in the air flow; the forced passage of the air flow through bulkheads, grilles, or holes cut in sheet metal capable of selectively interfering with the suspended particles.

[0010] Some examples of dust abatement equipment are described and illustrated in patents JP 167437, JP 71318, CH 680986, IT 1295248, IT 1235262, IT1992PT00009U, IT 1158230, US 3,782,080, US 3,702,048, US 3,57,535,US 5,061,299, US 6,132,493, US 4,486,206, US 5,741,340, US 2002 / 0066262, US 6,059,866.

[0011] These embodiments, as well as all those known to date, have demonstrated sub-optimal performance in practice, especially when assessed in relation to production costs, i.e. operation complexity. In particular, abatement devices of the known type have manifested problems related to space requirements, wear and tear of filter septa, maintenance needs, production costs and energy consumption.

[0012] Presentation of the invention

[0013] The essential aim of the present invention is thus to eliminate the drawbacks of abatement devices of known types by providing an improved dust abatement device, which enables to drastically reduce the amount of dust and particles in the extracted air before returning it to the external environment.

[0014] A further aim of the present invention is to provide a dust abatement device that is constructively simple and inexpensive and operationally completely reliable. Brief description of the drawings

[0015] The technical characteristics of the invention, according to the aforesaid objects, can clearly be seen in the content of the claims below, and its advantages will become more readily apparent in the detailed description below, made with reference to the accompanying drawings, which represent a purely illustrative and non-limiting embodiment, wherein:

[0016] - Fig. 1 shows a schematic front view of the dust abatement device covered by the present invention;

[0017] - Fig. 2 shows a schematic side view of the abatement device in Fig. 1 ;

[0018] - Fig. 3 shows a schematic top view of the abatement device in Fig. 1 ;

[0019] - Fig. 4 shows a first axonometric view of the abatement device in Fig. 1 ;

[0020] - Fig. 5 shows a second axonometric view of the abatement device in Fig. 1 ; - Fig. 6 shows a third split axonometric view of a detail of the abatement device in Fig. 1 ;

[0021] - Fig. 7 shows a fourth split axonometric view of a detail of the abatement device in Fig. 1 ;

[0022] - Fig. 8 shows a first variant embodiment of a detail of the dust abatement device which is the object of the present invention relating to dust collection means;

[0023] - Figs. 9a and 9b show a second variant embodiment of the dust collectionmeans, in front and side views.

[0024] Detailed description of an example of a preferred embodiment

[0025] With reference to the accompanying drawings, the dust abatement device according to the present invention is collectively referred to as 1.

[0026] It is provided with a support structure 2 resting on the ground comprising a metal frame 3 with several legs bearing on top a raised base 4 on which a containment chamber 5 gravitates.

[0027] The latter is supported on said raised base 4 by a hopper 6 for conveying the dust and particles, and is bounded laterally by a cylindrical wall 5’ made of sheet metal, which extends at the bottom with continuity defining the conveying hopper 6 with a substantially conical conformation.

[0028] The same containment chamber 5 is connected to an intake duct 7 with a first intake opening 7’, capable of sucking in a flow of air from the external environment (the path of which has been indicated by an arrow) due to the action of ventilation means 8 described more clearly below.

[0029] The air channelled into the intake duct 7 is then conveyed through an upper portion 9 of the containment chamber 5, shaped in the form of a helical duct 10. The helical duct 10, delimited by separation septa 10’, spirals around a central duct 11.

[0030] The latter has a substantially cylindrical shape with a rectilinear course that extends centrally to the containment chamber 5 for its entire height until it reaches a lower portion 12 where it is provided with a second intake opening 13. Functionally, as a result of the vortex created within the helical duct 10, an initial separation of suspended particles and dust from the air flow takes place.

[0031] Subsequently, the particles and dust descend into the conveying hopper 6, which has the task of conveying them into suitable collection means 14 arranged below said raised base 4.

[0032] According to a main feature of the present invention, the abatement device 1 further comprises a connecting duct 15 connected to the central duct 11 by an elbow section 15’, so as to conduct the outgoing air flow from the containment chamber 5 to a tank 16, preferably but not necessarily equipped with a level indicator and / or level sensor 16”, containing a sanitising liquid 17 or more simply water.

[0033] Further, according to the preferred embodiment of the invention, both the connecting duct 15 and the tank 16 are each provided with an inspection port,denoted 15” and 16”’ respectively.

[0034] It is not excluded that, according to variants of the invention, one or both of these inspection ports 15” and 16”’ may not be present.

[0035] The air flow projected from the connecting duct 15 onto the free surface 18 of the sanitising liquid 17 is further purified, as many particles still present in suspension in the airflow itself remain embedded within the sanitising liquid 17.

[0036] The tank 16 is then connected to an expulsion duct 19 to return the purified air flow to the external environment. This latter expulsion duct 19 is provided with an inspection window 19’, through which the tank 16 can be accessed, and an expulsion opening 19” facing the external environment.

[0037] Preferably, but not necessarily, a flow sensor, not depicted in the figures, is provided in proximity to this expulsion opening 19” to measure the flow rate of the purified air exiting the aforementioned abatement device 1.

[0038] Further, as can be seen in Fig. 6, according to a preferred embodiment of the invention, a further droplet separator 25 is provided within said expulsion duct 19, to further purify the air, prior to its exit from the abatement device 1 through the expulsion opening 19”.

[0039] It cannot be ruled out that, in embodiments of the invention, such an additional droplet separator 25 may not be provided.

[0040] A communication port 20 is defined between the connecting duct 15 and the expulsion duct 19. In particular, this communication port 20 is defined inside the tank 16, as can be seen in Fig. 2.

[0041] According to the invention, as can be seen in Fig. 6, an airflow control damper 34 is arranged at said communication port 20 comprising a baffle 35, which, depending on its height position, adjusts the distance of the air flow from the free surface 18 of the sanitising liquid 17 contained in the tank 16, thereby achieving greater air filtration if the baffle 35 is positioned downwards. Naturally, this increases the pressure of the air that has to pass through this baffle 35, thereby decreasing the flow rate of the abatement device 1. Therefore, the baffle 35 must be adjusted to allow a trade-off between improved abatement and reduced flow. In detail, this baffle 35 is configured to be adjusted in height by means of the operational coupling between its side ends and the vertical rails defined at the aforementioned communication port 20.

[0042] The ventilation means 8, mentioned above, are mounted to intercept the airflow above the containment chamber 5 so as to act by drawing the flow from thesecond opening 13 of the central duct 11 and then forcing it into the connecting duct 15.

[0043] In accordance with a further feature of the present invention, as seen in Fig. 7, the abatement device 1 comprises washing means 21 arranged within the connecting duct 15 to further purify the air flow from suspended particles and dust.

[0044] In more detail, preferably but not necessarily, the washing means 21 comprise a distribution system for a sanitising liquid provided with a circulation pump 2T capable of taking a flow of sanitising liquid 17 from the tank 16 and sending it to a delivery duct 22, possibly provided with several branches 22’, and bearing a plurality of nozzles 23.

[0045] The latter are advantageously able to atomise the sanitising liquid 17 taken from the tank 16 to increase its interference with the air flow passing through the connecting duct 15, so as to incorporate a high residual quantity of dust and particles still present in the airflow itself.

[0046] The flow of liquid sprayed through the nozzles 23 is collected again inside the tank 16.

[0047] More specifically, according to the preferred embodiment of the invention, such nozzles 23 could be configured to generate a cone of water through which air passes, thereby retaining more dust.

[0048] Advantageously, when returning to the tank 16, the sanitising liquid determines, at the above-mentioned communication port 20, a cascade which further intercepts the airflow passing from the connecting duct 15 to the expulsion duct 19”.

[0049] The collection means 14, mentioned above, may simply be obtained by means of a removable carriage provided with a containment tank 27, operatively associated with an unloading mechanism 24, mounted on wheels 26 allowing the carriage to be moved between an operational position in which the carriage is arranged underneath the metal frame to receive the dust and particles from the conveying hopper 6, and a non-operational position in which the carriage is arranged outside the footprint of the abatement device 1 to allow easy removal of the particles and dust accumulated inside the tank 27 (see Figure 8).

[0050] According to an alternative embodiment, such a carriage might not be equipped with such an unloading mechanism 24.

[0051] Otherwise, in accordance with a different embodiment illustrated in Figs. 9aand 9b, the collection means 14 may provide for the presence of a compacting unit 28 equipped with an evacuation auger 33 capable of extracting the dust and particles collected by means of a second hopper 30 inside a duct 31 and evacuating them through an extraction port 32 from which they will then be disposed of in the traditional manner.

[0052] Operationally, the abatement device 1, described so far from a mostly structural point of view, provides for the tangential suction of the air flow and its consequent conveyance into the containment chamber 5, inside which the flow runs all the way down the helical duct 10, resulting in an initial abatement of dust and suspended particles.

[0053] At this point, the air rises in the central duct 11 and then descends again into the connecting duct 15, where it is first washed by sprays from the distribution system 21 of sanitising liquid 17, and is then further purified by contact with the sanitising liquid 17 contained in the tank 16 and by passage through the droplet separator 25 before being reintroduced into the external environment by ascending through the expulsion duct 19.

[0054] Advantageously, the abatement device 1 according to the present invention enables the purification of air contaminated with particles and dust in work environments quickly, effectively and at moderately low cost.

[0055] Therefore, the invention thus conceived achieves the intended purposes.

[0056] Obviously, it may also, in its practical realisation, take forms and configurations other than those illustrated above without, as a result, departing from the present scope of protection.

[0057] Furthermore, all parts may be replaced by technically equivalent elements and the dimensions, shapes and materials used may be any as required.

Claims

CLAIMS1) Dust abatement device (1), particularly for use in the tanning industry, characterised in that it comprises:- a support structure (2) resting on the ground;- a containment chamber (5) intended to receive a flow of air from the external environment through at least one intake duct (7), and capable of conveying it through at least one upper portion (9) thereof shaped in the form of a helical duct (10), extending around a central duct (11), to centrifugally separate suspended particles and dust in the airflow;- collection means (14) mounted below said containment chamber (5) to collect said dust and particles;- at least one connecting duct (15) connected to said central duct (11) to conduct said outflow from said containment chamber (5) to a tank (16) adapted to contain a sanitising liquid (17) adapted to absorb particles and dust remaining in suspension in said airflow;- at least one expulsion duct (19) connected to said tank (16) and separated from said connecting duct (15) by a communication port (20), there being arranged at said communication port (20) an air flow control damper (34) comprising a baffle (35) which, depending on its height position, regulates the distance of the air flow from the free surface (18) of said sanitising liquid (17) contained in said tank (16);- ventilation means (8) for taking said air flow from the external environment, force it through said ducts (7, 10, 11, 15, 19) and feed it purified back into the external environment.2) Abatement device (1) according to claim 1, characterised in that it comprises washing means (21) arranged within said connecting duct (15) for purifying said air flow from said suspended particles and dust.3) Abatement device (1) according to claim 2, characterised in that said washing means (21) comprise a distribution system (22, 22’) of a sanitising liquid (17), provided with a plurality of nozzles (23).4) Abatement device (1) according to claim 3, characterised in that said distribution system (22, 22’) is configured to draw said sanitising liquid (17) inside said tank (16), the sanitising liquid (17) emitted by said nozzles (23) being collected again inside said tank (16).5) Abatement device (1) according to any one of claims 3 or 4,characterised in that said nozzles (23) are configured to generate a cone of water through which air passes, thereby retaining a larger quantity of dust.6) Abatement device (1) according to any one of the preceding claims, characterised in that said ventilation means (8) are mounted above said containment chamber (5) and act to intercept said air flow by drawing said air flow from said central duct (11) and forcing said air flow into said connecting duct (15).7) Abatement device (1) according to any one of the preceding claims, characterised in that it comprises at least one conveying hopper (6) continuously fixed below said containment chamber (5) for guiding said dust and particles towards said collection means (14).8) Abatement device (1) according to claim 7, characterised in that said collection means (14) comprise a removable carriage provided with a containment tank (27) arranged below said conveying hopper (6) to allow the particles and dust accumulated in said tank (27) itself to be easily extracted.9) Abatement device (1) according to any one of the preceding claims, characterised in that it is configured to allow said air flow to cross said helical duct (10) downwards, said central duct (11) upwards, said connecting duct (15) downwards and said expulsion duct (19) upwards.10) Abatement device (1) according to any one of the preceding claims, characterised in that a flow sensor is provided in proximity to the expulsion opening (19”) of said expulsion duct (19) for measuring the flow rate of the purified airflow exiting said abatement device (1).11) Abatement device (1) according to any one of the preceding claims, characterised in that a droplet separator (25) is provided within said expulsion duct (19) for further purifying the air, prior to its exit from said abatement device (1).12) Abatement device (1) according to any one of the preceding claims, characterised in that said tank (16) is provided with a level indicator (16’) and / or a level sensor (16”).13) Abatement device (1) according to any one of the preceding claims, characterised in that both said connecting duct (15) and said tank (16) are each provided with an inspection port (15”, 16”’).

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