WO2020144595A1

WO2020144595A1 - A cleaning device and a cleaning method for a dust collector.

Info

Publication number: WO2020144595A1
Application number: PCT/IB2020/050120
Authority: WO
Inventors: Vainer Marchesini
Original assignee: Wamgroup S.P.A.
Priority date: 2019-01-08
Filing date: 2020-01-08
Publication date: 2020-07-16
Also published as: CN113573793B; WO2020144595A9; IT201900000175A1; CN113573793A

Abstract

Described is a device and a method for making a cleaning system for dust collectors (1) for gaseous fluids, with a vertical structure, equipped with vertical channels (2) for introducing the fluid to be freed from dust and vertical conduits (3) for the outfeed of the fluid from which the dust has been removed. The device comprises: a hammering device (4, 104) to cause, on command, percussion strokes on a head of the dust collector, an insulation system (5, 105) which, on command, is positioned either in an open position or in a closed position which, respectively, allow or prevent the flow towards the outside of the fluid coming from the conduits; first means for bringing the insulation system to the closed position and for actuating the hammering device for a variable number of percussion strokes as desired; second means for keeping the insulation system in the closed position during the operation of the hammering device, and for bringing the insulation system to the open position at the end of the hammering. The method, as well as a hammering step which causes the detachment of the dust from the filtering channels, comprises the following steps: using a first energy source, actuating an actuator which acts on an insulation system for preventing the outflow of fluid from which dust has been removed towards the clean fluid zone; using a second energy source, actuating a constraint which maintains the interruption of the outflow of the fluid from which dust has been removed and, with the first energy source, continuing the hammering step for a predetermined time and number of strokes; interrupting both the energy sources to end both the hammering step and the step for preventing the outflow of the fluid from which dust has been removed towards the clean fluid zone and re-establishing the initial condition.

Description

A CLEANING DEVICE AND A CLEANING METHOD FOR A DUST

COLLECTOR

The invention relates to a cleaning device and a cleaning method for a dust collector of gaseous fluids.

The dust collectors to which the cleaning system (device and method) according to the invention is applied are specifically industrial machines (dust collectors) which process gaseous fluids, normally air, contaminated with pollutants from industrial transformation processes, with the presence of dust in the air in a decidedly significant percentage since it is much greater than the normal presence of dust in the ambient air. The purpose of these machines is to treat the polluted industrial air to make it compatible with discharge into the atmosphere and/or within the surrounding work environments. These dust collectors can be used to remove the dust from gaseous fluids consisting of air containing dust which is generated in the loading of silos or in transformation, movement, cutting or other industrial processes, actuated, for example, by mixing devices, conveyors, packaging machines, dosing machines, thermal or mechanical cutting machines and/or the like; these gaseous fluids cannot be discharged into the atmosphere or reused without prior elimination of the dust which they contain. These dust collectors, which occupy an overall volume which may even be several cubic metres, are normally made with one or more filter units in each of which there are numerous filtering elements which use one or more cleaning systems.

In their industrial applications these dust collectors treat air containing fine dusts, defined as such when their grain size varies from approximately 1 micron to 200 microns, which have concentrations which vary from approximately 0.5 gr/m3 to 500 gr/m3.

Due to the high quantity of dust in the air to be filtered, the filtering elements of the dust collector tend to become clogged very quickly. As a result, these dust collectors must be combined with automatic or semi-automatic periodic cleaning systems (intervention of the cleaning system at the discretion of the operator and not controlled by a logic system).

In an industrial dust collector, the cleaning system is a critical element for the correct operation of the dust collector: with the concentrations of dust in the fluids typical of these applications the dust collector would rapidly go out of service if the filtering surface is not frequently and effectively freed of the excess of dust deposited on it.

The systems for cleaning the filtering element, inside the industrial dust collector filter, are of the mechanical and/or pneumatic type:

A known pneumatic system comprises one or more jets of compressed air which is periodically blown inside the space defined by the filtering surface. The compressed cleaning air therefore follows a counter-current path relative to the path of the contaminated air (that is, from the inside to the outside of the filtering surface).

Another known pneumatic system comprises one or more low pressure air jets located in a position close to the filtering element and directed in a precise manner in the channel to be cleaned of the filtering element.

A known mechanical system performs the shaking in the lower part of the filtering element obtained through a comb which is interposed between the various filtering elements and moves them in a horizontal direction.

Another mechanical system produces a vibration which is usually applied in the upper part of the filtering element.

In any case, all the cleaning systems are designed to clean the filtering media by dragging the particles, obtained with cleaning fluid currents, or by shaking the filtering fabric which causes the detachment of the particles from the filtering fabric and their falling by gravity.

Dust collectors are currently known which have a plurality of tubular filtering elements, with cicular, oval or polygonal cross-sections, which have an open end and a closed end in such a way as to have a side from which only dirty air enters and a side from which only clean filtered air is discharged. The outer casing of these filtering elements, which represents the filtering surface, may be made of fabric or cellulose of various types and may be smooth or provided with pleats; the pleats increase the nominal filtering surface but often define, in their cusps, sectors where the dust hides in a more difficult way to remove and thereby making the active filtering surface less, sometimes also significantly, than the nominal filtering surface. In fact the sharp edges of the pleated elements are the starting point for the adhesion of the dust and the formation of significant lumps which obstruct the passage of air and lower the filtering efficiency.

It is therefore of fundamental importance to find a geometry which allows the least possible spaces for accumulating the dust; however, the cleaning system which detaches the dust from the filtering element and restores the operational efficiency of the filter is of even grater importance.

The detachment of the dust must be performed in a very short time and with the least possible energy consumption.

As well as reducing the filtering surface offered to the air, the fact that the dust retained in the pleats remains stagnant is particularly serious in food applications where the stagnant dust is seriously negative due to the risk of proliferation of the bacterial charge; the pleats are also not very functional for all the dusts which tend to be compacted. In any case, the presence of a pleating or of a material which does not have the necessary rigidity results in a greater difficulty in obtaining an effective cleaning system.

Depending on the operating mode of the dust collector, the gaseous fluid with the dust to be removed can enter from the open end of the filtering element or the gaseous fluid without the dust can be discharged from the open end of the filtering element; in the first case, the dust deposits in the inner surface of the filtering element whilst in the second case the dust deposits on its outer surface. The cleaning system may be positioned on both sides of the filtering element, however it is preferably installed on the side from which the clean air comes out.

In the known dust collectors, the filtering surface is normally associated with a reinforcement structure, inside or outside the filtering element, which is designed to prevent, during operation of the dust collector, any deformation of the filtering element which would reduce the filtering surface exposed to the flow of fluid from which dust is to be removed.

The construction of these dust collectors must deal with problems which are typical and specific for them which, as mentioned, have considerable dimensions and must filter large quantities of gaseous fluids. For example, it is necessary to attempt to increase the ratio between the active filtering surface and the space occupied by the filter, that is to say, to increase the filtering efficiency with the same size as other filters of the same type; it is also necessary to reduce, as far as possible, the energy consumption necessary for the operation and cleaning of these dust collectors.

The current cleaning systems, in particular those of the mechanical type to which reference is made, are quite complex to construct and their operation is not very versatile. Moreover, their effectiveness is not always entirely satisfactory.

The object of the invention is to provide a method and a device which are able to provide a cleaning system for a dust collector which resolves the above-mentioned problems of the prior art in a better way than prior art cleaning systems applied to a dust collector of the same type described above.

In a first aspect of the invention, there is provided a device for obtaining a cleaning system for cleaning dust separators for gaseous fluids, to be used with dust separators which have a vertical structure and comprise a plurality of vertical channels with an open end for the infeed of the fluid to be freed from dust and a plurality of vertical conduits with an open end for the outfeed of the fluid from which the dust has been removed, in which the open ends of the channels and conduits open onto opposite heads of the dust separator, of the type comprising a hammering device for causing, on command, percussion strokes on a head of the dust separator, characterised in that: the device comprises an insulation system which may adopt, on command, an open position, in which it allows the flow towards the outside of the fluid coming from the open ends which open onto the head of the dust separator, and a closed position which prevents said flow; first means for moving, on command, the insulation system to its closed position and for causing a step of actuating the hammering device for a number of percussion strokes, which is variable as required; second means for keeping the insulation system in its closed position during the step of actuating the hammering device, and for allowing the insulation system to be brought back to the open position at the end of the hammering step.

An advantage of the invention is that it provides an effective cleaning system, which has reduced overall dimensions and which functions with a low energy consumption.

Another advantage of the invention is that it provides a device which has a structure with a considerable solidity and robustness which can be installed to achieve various advantages: greater lightness, smaller dimensions, better integration with process machines or industrial plants.

Still another advantage of the invention is to provide a method for making a cleaning system which is easy to set up on the basis of the conditions of the dust which is filtered, that is to say, on the basis of the grain size, the types and the water content of the dust.

These objects and advantages and others are all achieved by this invention as described in the appended claims.

Further features and advantages of the invention will become more apparent from the detailed description which follows of the steps of the method according to the invention and of preferred, but not exclusive embodiments of it, for making the dust collector according to the invention, illustrated purely by way of non-limiting example in the accompanying drawings, in which:

• Figure 1 shows a schematic section of a dust collector to which is associated a first embodiment of the cleaning device according to the invention;

• Figures 2a, 2b, 2c, 2d show schematic sections of the first embodiment of the cleaning device according to the invention illustrated in various operating conditions;

• Figure 3 is a perspective view, with some parts cut away in order to better illustrate others, of the first embodiment of the cleaning device according to the invention;

• Figure 4 is a perspective view, with some parts cut away in order to better illustrate others, of a second embodiment of the cleaning device according to the invention.

The device according to the invention is used for making a cleaning system for dust collectors 1 for gaseous fluids. This device is used to clean dust collectors which have a vertical structure, preferably rigid, and which comprise a plurality of vertical channels 2 with an open end for introducing the fluid from which dust is to be removed and a plurality of vertical conduits 3 with an open end for the discharge of the fluid from which dust has been removed; the open ends of the channels and conduits lead to opposite heads of the dust collector. The side walls of the conduits and channels are made of a filtering fabric.

The description and the drawings below refer to a dust collector in which the open end of the vertical channels, in which the fluid from which the dust is to be removed enters, is positioned in the lower head whilst the open end of the vertical conduits, from which the air from which dust has been removed comes out, is positioned in the upper head of the dust collector. The ends of the conduits and of the channels are firmly connected to the upper head 20 of the dust collector; the head is an integral part of the rigid structure of the dust collector and is so conformed as to hermetically seal the ends of the channels and leave open the ends of the conduits. In that way, the dust collector clearly separates the zone containing the fluid containing dust (in the lower part) and the zone containing the fluid from which dust has been removed (in the upper part).

Like the prior art devices of this type, the device according to the invention comprises a hammering device 4, 104 to cause percussion strokes on the head, in the drawings on the upper one, of the dust collector. The device according to the invention comprises an insulation system 5, 105 which may adopt on command an open position, in which it allows the flow towards the outside of the fluid coming from the open ends which lead to the upper head 20 of the dust collector, and a closed position which prevents the flow. During normal operation of the dust collector, the insulation system of the device according to the invention is in its open position. To perform the cleaning of the dust collector there are first means for bringing, on command, the insulation system to its closed position; these first means also cause a step of actuating the hammering device for a number of percussion strokes variable as desired. The device comprises second means which allow the insulation system to be kept in its closed position during the step of actuating the hammering device; these second means also allow the insulation system to be returned to the open position at the end of the hammering step.

The said first means comprise a cam 6, 106 which is rotated, on command, by an electric motor 8, 108 and which has a profile which interacts with the insulation system to move it from the open position to the closed position; the cam is also provided with a contact element 7, 107 which, during its rotation, actuates the hammering device. ++++

Said second means comprise an electromagnetic device (for example, an electromagnet 9, 109) which is energised together with the electricity supply of said electric motor; when the insulation system, which comprises at least a part 13, 1 13 made of ferromagnetic material, is brought to its closed position, the ferromagnetic part 13, 1 13 of the insulation system comes into contact with the electromagnetic device and is retained by the latter in this closed position. In this way, the second means prevent, during the rotation of the cam which continues as desired according to predetermined operating programs, interaction between the insulation system and the cam profile. In other words, once the insulation system is blocked by the electromagnet, the cam may continue to rotate, so as to actuate the hammering device to cause percussion strokes on the upper head of the dust collector, whilst the insulation system remains in its closed position. The hammering device of the cleaning device according to the invention comprises a tower 10, 1 10 which is fixed relative to the head 20 of the dust collector. Normally, the tower is fixed to a frame which surrounds the upper head of the dust collector. The device according to the invention comprises a distributor 25a, 125 which is securely rested on the upper head of the dust collector and which is designed to uniformly distribute the shock wave on the surface of the head 20 of the dust collector. This distributor is obviously shaped and positioned in such a way as not to obstruct the open ends of the conduits which lead to the upper head, so as not to prevent the flow of the cleaned fluid through the open ends.

Inside the tower slides a percussion element 1 1 , 1 1 1 which rises and lowers cyclically to cause shock waves on the surface of the head of the dust collector. The percussion element is maintained and returned to its lowered position, which brings it into contact with the head of the dust collector, by means of a first compression spring 24, 124. The movement of the percussion element is controlled, as described in more detail below, by said cam.

According to a first embodiment, said insulation system 5 comprises a frame 14 which surrounds in a sealed fashion the head of the dust collector, outside of which is connected a ferromagnetic contact element 13. Also fixed to the frame there is a support, to which the tower is connected, which in this embodiment is represented by a pair of guides 25. Under the guides there is a frame 25a which has the function of a distributor for correctly discharging the stresses imparted by the percussion element. The frame 25a may also be integrated in the head of the dust collector. The insulation system also comprises a supporting base 16 on which is positioned a hood 17 which encloses the head of the dust collector and the hammering device. The supporting base is hinged to said frame and has, on the opposite side of the hinge, the electromagnet 9. Obviously, it is possible, alternatively, to connect the electromagnet to the frame and the ferromagnetic contact element to the supporting base.

Elastic means are provided, which in this embodiment are made by means of a second compression spring 18 positioned between the head of the dust collector and the supporting base, which are designed to keep the insulation system in the open position.

The profile of the cam 6 interacts on the upper part of the supporting base which, in its rotation, presses on the supporting base and, overcoming the force of the spring, causes the rotation of the supporting base and moves the electromagnet 9, in the meantime energised, into contact with the ferromagnetic contact element 13 which locks the insulation system in the closed position. In this closed position the supporting base rests in a sealed fashion on said frame.

The cam is connected to a contact element, which in this embodiment consists of a lifting pin 7 of which only a base is shown in the drawings since the pin is positioned with the axis parallel to the axis of rotation of the cam; the pin 7 interacts with a contact element 26 provided on the percussion element. The pin pushes the percussion element upwards during an arc of its rotation and compresses the first spring 24; in a subsequent rotation arc the percussion element is released and, pushed by the first spring, falls downwards, causing a shock wave on the head 20 of the dust collector. The pre-loading of the spring 24 makes the strike of the percussion element much more effective than it would be with a percussion element falling by gravity. These operating steps are illustrated in Figure 2.

According to a second embodiment of the cleaning device according to the invention, the insulation system 105 comprises a hood 1 17 which encloses the head 20 of the dust collector and the hammering device. According to this embodiment, the tower of the hammering device is fixed, by means of brackets 1 10, to an outer frame of the dust collector; the percussion element of the hammering device acts on a distributor, represented by a grille 125, which is positioned on the head of the dust collector and is designed to correctly discharge the stresses imparted by the percussion element; the distributor in any case does not obstruct the openings provided on the head. The cap surrounds in a sealed fashion the head of the dust collector and at the top is equipped with an opening 1 19 which is open towards the outside when the insulation system is in the open position. The insulation system comprises a shutter 120, in the form of a cone with the larger base facing towards said opening, on which interacts the cam profile of the hammering device. The shutter is shaped and positioned in such a way as to be able to close, on command, said opening of the hood; on the perimeter edge of the larger base of the shutter there is a gasket which guarantees the seal of the closing of the hood. The shutter illustrated has the shape of a cone, even if different shapes of the shutter are possible.

The shutter has an axial rod 121 which is slidable above in a bushing provided of a cross-like element 122 provided on the opening of the hood; the lower part of the rod is inserted slidably inside a cavity 123 provided on the percussion element of the hammering device.

On the upper part of the rod 121 there is a ferromagnetic contact element 1 13 on the end of stroke of the rod there is an electromagnet 109 which, when energised, interacts with the contact element 1 13 and locks the shutter in its closed position which closes the opening of the hood. Obviously, also in this embodiment it is possible to reverse the positions of the electromagnet and of the ferromagnetic contact element.

Elastic means are provided which in this embodiment are made by means of a second compression spring 1 18 positioned between the lower base of the shutter and the cross-like element provided on the opening of the hood, which are designed to keep the shutter in the open position.

According to this embodiment, following its rotation the end 107 of the cam interacts with a contact element 126 provided on the percussion element. The cam pulls the percussion element upwards during an arc of its rotation and compresses the first spring 124; simultaneously, the percussion element pushes the shutter upwards until its ferromagnetic contact 1 13 is brought into contact with the electromagnet 109 which in the meantime has been energised; in this way, the shutter, and therefore the insulation system, is locked in its closed position. In a subsequent rotation arc the percussion element is released and, pushed by the first spring 124, falls downwards, causing a shock wave on the head 20 of the dust collector. Also in this case, the pre-loading of the spring 124 makes the strike of the percussion element much more effective than it would be with a percussion element falling by gravity.

As stated above, in both the embodiments described, once the insulation system is locked by the electromagnetic device, the cam may continue to rotate, so as to actuate the hammering device to cause percussion strokes on the upper head of the dust collector, whilst the insulation system remains in its closed position.

The operation of the cleaning system according to the invention occurs as described below.

During normal operation of the dust collector, the insulation system of the device according to the invention is in its open position and the fluid from which dust has been removed can freely escape to the outside; the hammering device is inactive and the electromagnetic devices, both in the first and the second embodiment, are not energised.

When the dust collector is to be cleaned, using an electricity supply and with the methods indicated above for the embodiments described, the first means which move the insulation system to the closed position are activated, then the second means which energise the electromagnetic devices which keep the insulation system in the closed position are activated, and the hammering device is activated. The flow towards the outside of the fluid from which dust has been removed is interrupted, and obviously the flow of fluid from which dust is to be removed is interrupted (in short, the insulation system interrupts the flow of fluid through the dust collector), and the hammering device is operated repeatedly and exerts on the filtering element the strokes which cause the detachment of the dust from the inner surface of its vertical channels. The falling downwards, by gravity, of the detached dust is possible since the flow of fluid to be cleaned of dust is, as mentioned, interrupted and does not obstruct the falling.

When the hammering device has given the desired number of strokes, which, as mentioned above, are freely selected and determined by the operator on the basis of the type of dust, the humidity of the environment and the characteristics of the filtering device, the electricity supply is switched off. This causes the hammering device to stop and the action of the electromagnetic devices is interrupted in such a way that the insulation system is free to return, pushed by the second means, to its open position. The hammering device is stopped with a precise angular position of the motor in such a way that its cam does not obstruct the insulation system from returning to the completely open position.

With the cleaning device in this position the flow of fluid is re-activated through the dust collector, which therefore returns to its normal function of removing the dust.

In this way, the cleaning system described allows the insulator to be closed for a desired length of time and at the same time releases a desired number of strokes. This system makes it possible to set up the cleaning system, adapting it to more or less fine dust and more or less clogging or to link the number of strokes to a system for controlling the efficiency of the filtration. The change in the number of strokes need not be accompanied by a change of mechanical parts but may be determined by the operator by simply varying the electrical power supply time of the device.

The cleaning method according to the invention is used for dust collectors of gaseous fluids which have a vertical structure which comprise vertical filtering channels in which is introduced the fluid from which the dust is to be removed coming from a zone of fluid containing the dust, and vertical conduits from which leaves, towards a clean fluid zone, the fluid from which dust has been removed coming from the filtering channels. Like some prior art methods, it comprise a hammering step which causes the detachment of the dust from the filtering channels and the falling of the dust, by gravity, towards a collection point.

The method according to the invention is implemented starting from an initial normal operating situation of the dust collector, in which the fluid from which dust is to be removed enters the vertical channels, deposits the dust inside the vertical filtering channels leaves towards the clean environment by the vertical conduits; the method starts to be actuated when, using suitable analysis systems of known type, it is assessed that the operation of the dust collector is no longer acceptable due to the excessive deposit of dust in the filtering channels.

The method according to the invention comprises an initial step of actuating, by means of a first energy source, an actuator which acts on an insulation system to prevent the escape of the fluid from which dust has been removed towards the clean fluid zone. According to a further step, there is an actuation, by means of a second energy source, of a constraint which maintains the interruption of the outfeed of the fluid from which dust has been removed; this step also comprises continuing to actuate, by means of the first energy source, the actuator to cause the hammering step for a predetermined time and a predetermined number of strokes. Preferably, said first and second energy sources provide energy of the electrical type; in that case, an electro-mechanical actuator and an electromagnetic constraint are used.

Once the action of the hammering device, which causes the detachment of the dust from the filtering surfaces and the falling by gravity of the dust in a collection zone, is considered sufficient to clean the filtering surfaces, the step is performed of interrupting both the energy sources to complete both the hammering step and the step of preventing the discharge of the fluid from which dust has been removed towards the clean fluid zone for restoring the initial operating condition of the dust collector.

If the first and second energy sources supply electricity, they are conveniently activated and deactivated very simply by providing a single command, for example by means of a normal electric switch, which allows electricity to be supplied both to the electro-mechanical type actuator and to the electromagnetic constraint. In short, a single command is used which, by means of a same source of electricity (which constitutes both the first and the second energy sources), actuates the devices of the cleaning system.

The cleaning device according to the invention allows, in both the embodiments described above, the method to be implemented since it has all the elements which are able to actuate the various steps of the method.

Claims

1 . A cleaning device for cleaning a dust collector for a gaseous fluid, comprising a hammering device (4, 104) operable for causing percussion strokes on a head (20) of the dust collector, an insulation system (5, 105) displaceable between an open position, in which the insulation system (5, 105) allows fluid communication between the dust collector and an environment outside the dust collector, and a closed position in which the insulation system (5, 105) prevents fluid communication between the dust collector and said environment, first means operable for bringing the insulation system in the closed position and for actuating the hammering device thereby starting a hammering step, characterized in that the cleaning device further comprises second means operable when the insulation system is in the closed position in order to keep the insulation system in the closed position, so that the hammering device can be actuated for a freely selectable number of percussion strokes while the insulation system remains in the closed position, the second means being further configured to allow the insulation system to be brought back in the open position at the end of the hammering step.

2. A cleaning device according to claim 1 , characterised in that the first means comprise a cam (6,106) which is rotatable, on command, and which has a profile suitable for interacting with the insulation system to move it from the open position to the closed position; the cam being provided with a contact element (7,107) which, during rotation of the cam, is arranged for actuating the hammering device; the second means are configured to prevent interaction between the insulation system and the profile of the cam.

3. A cleaning device according to claim 2, characterised in that the cam is rotatingly drivable by an electric motor (8,108); the second means comprise an electromagnetic device (9,109) suitable for being energised when the electric motor is electrically powered for blocking the insulation system in its closed position.

4. A cleaning device according to claim 1 , characterised in that it comprises a distributor (25a, 125) for distributing on the head of the dust separator the impact waves caused by the hammering device.

5. A cleaning device according to claim 3, characterised in that: the hammering device (4) comprises a tower (10), fixed relative to the head (20) of the dust separator, a percussion element (1 1 ) is slidiable inside the tower (10), the percussion element (1 1 ) being controlled by the cam (8) and being configured for rising and descending cyclically to give percussion strokes which cause impact waves on the head of the dust separator; the insulation system (5) comprises a frame (14), which sealingly surrounds the head of the dust separator, a ferromagnetic contact element (13) being connected externally of the frame (14); the insulation system (5) comprises a supporting base (16), on which is positioned a hood (17) which encloses the head of the dust separator and the hammering device (4), the hood (17) being hinged to the frame and having at the opposite end the electromagnetic device (9); the profile of the cam (8) interacts on the supporting base; elastic means (18) are provided suitable for keeping the insulation system in the open position.

6. A cleaning device according to claim 5, characterised in that, in the closed position of the insulation system, the supporting base sealingly rests on the frame.

7. A cleaning device according to claim 3, characterised in that: the hammering device (104) comprises a tower (1 10), fixed relative to the head (20) of the dust separator, a percussion element (1 1 1 ) is slidable inside the tower (1 10), the percussion element (1 1 1 ) being controlled by the cam (106) and being configured for rising and descending cyclically to give percussion strokes which cause impact waves on the head of the dust separator; the insulation system (105) comprises a hood (1 17), which encloses the head of the dust separator and the hammering device (104) and which underneath sealingly surrounds the head of the dust separator, an opening

(1 19) being provided at the top of the hood (1 17), the opening (1 19) being open towards the outside when the insulation system is in the open position; it comprises a shutter (120) on which the profile of the cam (106) interacts, the shutter (120) being shaped and positioned in such a way as to close, on command, the opening (1 19); the electromagnetic device comprises an electromagnet (109) which blocks the shutter (120) in its closed position in which it closes the opening of the hood; elastic means (1 18) are provided suitable for keeping the shutter in the open position.

8. A cleaning device according to claim 7, characterised in that the shutter

(120) has the shape of a cone, with a larger base facing towards the opening, and has an axial rod (121 ) which is slidable above in a bushing provided on a cross-like element (122) provided on the opening of the hood; the lower part of the rod is inserted slidably inside a cavity (123) provided on the percussion element (1 1 1 ) of the hammering device; the shutter is pushed towards the opening of the hood, for closing it. by the rising of the percussion element.

9. A cleaning method for a dust separator of gaseous fluids, to be used with dust separators having a vertical structure which comprise vertical filtering channels in which the fluid to be freed from dust is introduced, said fluid coming from a zone of fluid containing the dust, the dust separators further comprising vertical conduits from which the fluid freed from dust escape, towards a clean fluid zone, the fluid freed from dust coming from the filtering channels, in which a hammering step is provided which causes detachment of the dust from the filtering channels and falling of the dust, by gravity, towards a collection point, characterised in that, starting from an initial situation of normal operation of the dust separator, the method comprises the following steps: by means of a first energy source, actuating an actuator which acts on an insulation system for preventing the outflow of fluid from which dust has been removed towards the clean fluid zone; by means of a second energy source, actuating a constraint which maintains the interruption of the outflow of the fluid from which dust has been removed and with the first energy source continuing to actuate the actuator for causing the hammering step for a predetermined time and number of strokes; interrupting both the energy sources in order to end both the hammering step and the step of preventing the outflow of the fluid from which dust has been removed towards the clean fluid zone and in order to re-establish the initial condition.

10. A method according to claim 9, characterised in that the first and second energy sources supply electricity to the actuator, which is of the electromechanical type, and to the constraint which is of the electromagnetic type.

1 1. A method according to claim 10, characterised in that the steps of activating and deactivating the first and second energy sources are obtained by means of a single command which activates a single source which provides both the first and the second energy sources.