Patent Description:
In material handling and processing such as breaking, milling, hammering and the like of chunks, lumps, fibers or particulates of material or matter into smaller fractions or particles, such as fine powder, and in conveying such fractured or particulate material, for example in a gaseous fluid stream, such as by pneumatic transport lines, and in separation equipment or filter equipment for filtering particulate matter from the gaseous fluid stream, and other material handling equipment, particulate matter may adhere to a wall of a chamber in which the particulate matter is introduced.

Such adherence of particulate matter may not only lead to loss of yield, processing failures and production breakdowns due to clogging, caking and the like of particulate matter, but also causes material cross-contamination when a batch of new material having different properties compared to a previous batch is processed or handled by a same device in a same processing chamber thereof.

Removing particulate matter adhered to a wall, in particular in devices arranged for handling food, tobacco, mineral, chemical and pharmaceutical products, is technically quite a challenge because of strict safety requirements in the processing and handling of such products, in particular in view of requirements preventing cleaning equipment to be introduced in a chamber for handling and processing food, tobacco, mineral, chemical and pharmaceutical products, for example.

Document <CIT>) describes a cleaning device inducing sonic vibrations showing the features described in the preamble of appended claim <NUM>.

Accordingly, there is a need for safely impeding adhesion of and/or removing adhered particulate manner in a device for material handling and processing.

In a first aspect of the present disclosure, there is provided a device according to independent claim <NUM>, comprising a housing enclosing a chamber surrounded by an inner wall of the housing, arranged for introducing particulate matter in the chamber, the device having an external support structure supporting at least one actuator element arranged for inducing sonic vibrations in the housing and the chamber, thereby providing at least one of impeding adherence of particulate matter at the inner wall of the chamber and releasing particulate matter adhered to the inner wall of the chamber.

In another aspect of the present disclosure, there is provided a method of operating the device according to independent claim <NUM>.

It has been found that by subjecting the housing to sonic vibrations, that is vibrations in the ultrasound frequency range from <NUM> and upwards, such as vibrations in a frequency range of <NUM> - <NUM>, an acoustic pressure is provided in the chamber, thereby effectively impeding or reducing adherence of particulate matter at the inner wall of the chamber, or even preventing adherence, while already adhered particulate material can be removed from the inner wall of the chamber for cleaning purposes.

It has also been found that subjecting the housing to frequencies other than the aforementioned frequencies also leads to good results. In particular in a device according to the invention, such vibrations are provided with one or more of a frequency range from <NUM>-<NUM>, from <NUM>-<NUM>, and <NUM>-<NUM>, at which frequencies the adherence of particulate matter at the inner wall of the chamber is reduced, or even prevented. It has been found that of the mentioned frequencies, the lower frequencies below the <NUM> are more effective in large systems or applications with a large (cylindrical) housing. Hence, depending on the application and dimensions of the component that is to be cleaned, one or more of the above mentioned frequency ranges may be selected.

As the actuator element is arranged at the outer side of the housing and is not in physical contact with the material or products processed or handled in the chamber, safety requirements imposed on the device for handling and processing of food and medical products, as mentioned above, can be complied with in the same manner as for a device not comprised of the solution according to the present disclosure.

In the present description, throughout all aspects and embodiments thereof, the term "actuator element", or "at least one actuator element" are used, which are to be construed as referring to one single actuator element, two actuator elements, or more actuator elements such as <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or more than <NUM>.

Due to the cleaning properties of the present disclosure, cross-contamination between batches of different products having different physical properties due to remaining particulate matter in the chamber, is effectively avoided with the present disclosure.

The term 'particulate matter' as used in the present description and the claims is to be construed as referring to particles of any type of material, be it in powder, fine powder form or fibrous form, and defined by weight per volume, such as grams/m<NUM>, particle diameter, particle length, or any other measure used for characterizing particulate matter.

In an embodiment of the present disclosure, the device comprises a control unit for controlling excitation of the at least one actuator element in at least one of a first vibrating mode and a second vibrating mode, wherein the first vibrating mode is inducing less strong vibrations than the second vibrating mode.

With the control unit, different modes of vibration can be induced in the housing and the chamber, including different grades of acoustic pressure inside the chamber, by controlling the intensity of the vibrations performed by the actuator element and/or by provoking different acoustic wave patterns inside the chamber, by controlling the vibration frequency and/or by superimposing a modulation signal at an excitation signal of the actuator element, thereby modulating the vibrations provided in one or more of strength, frequency and phase.

In a further embodiment of the device according to the present disclosure, the control unit is arranged for exciting the at least one actuator element in the first vibrating mode when the chamber is charged with particulate matter, i.e. is subjected to a particulate matter introducing operation, and for exciting the at least one actuator element in the second vibrating mode when the particulate matter is discharged from the chamber, i.e. the chamber is free from a particulate matter introducing operation.

That is, during operation of the device wherein particulate matter is handling or processed in the chamber, the control unit is operated in the first vibrating mode for generating a relative low acoustic pressure inside the chamber, such that the normal or intended material processing or handling is not impeded by the acoustic pressure. However, the thus generated acoustic pressure should be of a sufficient strength for bringing particulate matter close to and along the inner wall of the chamber in a state of turbulence, thereby effectively impeding or reducing or even preventing adherence of particulate matter to the inner wall, compared to a device not arranged in accordance with the present disclosure.

For cleaning of the chamber, after having handled or processed a batch of particulate matter, the control unit is operated in the second vibrating mode, arranged for generating a maximum or near maximum acoustic pressure in the chamber, of a strength for removing particulate matter already adhered to the inner wall of the chamber.

In another embodiment, the device comprises a gas stream generating unit, arranged for providing, i.e. generating and forcing, a cleaning gas stream, such as a stream of air or an inert gas, for example, through the chamber at least when the actuator element is excited in the second vibrating mode.

In another embodiment, the device comprises several distinct operating modes. One of the operating modes being a start mode, another mode being a stop mode. In an embodiment, the start and stop modes are performed immediately one after the other, so that immediately after a rest or inactive mode, a start and stop sequence follows. In a further embodiment, this start-stop sequence can also be repeated several times, by which, especially for particular applications, the cleaning process is further improved. The thus generated cleaning gas stream is of a capacity and speed for transporting the released particulate matter out of the chamber. Such a cleaning gas stream allows the cleaning of chambers oriented in any direction, such as an elongated chamber longitudinally extending in horizontal direction, for example. The gas stream generating unit may be operated in a suction mode and/or blowing mode for forcing the cleaning gas stream through the chamber.

In a particular embodiment of the present disclosure, for processing a gaseous fluid stream comprising particulate matter, the chamber is provided with at least one inlet for receiving the gaseous fluid stream, and at least one outlet for discharging gas and particulate matter not collected in the chamber.

For this particular embodiment, the control unit may be arranged for exciting the at least one actuator element in the first vibrating mode when the gaseous fluid stream is present in the chamber, and for exciting the at least one actuator element in the second vibrating mode when the gaseous fluid stream is absent of the chamber.

In this particular embodiment, for cleaning purposes of the chamber, the cleaning gas stream may be introduced in upstream and/or downstream direction of the flow direction of the gaseous fluid, in particular using the inlet and outlet of the chamber, if available, or an inlet and/or outlet of the chamber separate from the inlet and outlet of the gaseous fluid stream.

In practice, for devices arranged for handling and processing fine powder products, explosion safety requirements and regulations are in place. That is, the housing has to be constructed to withstand high gas pressures, such as up to and even above <NUM> bar(a), for example. As a result, the housing of such devices is made of relatively thick steal, such as carbon steel or stainless steel, for example, or an other sturdy material, having a thickness ranging, for example, from <NUM> to <NUM> or even up, resulting in a very rigid and heavy housing, up to a few tons of weight.

Also housings of huge devices, that is housings having a height and width of several meters, dimensions that are not uncommon in chemical and food processing, can be very heavy and rigid. Hence, inducing sonic vibrations in such rigid and sturdy housings is technically problematic.

In a further embodiment of the present disclosure the device comprises an outer housing and an inner housing arranged inside the outer housing, the inner housing enclosing the chamber, and wherein the outer housing comprising the support structure supporting the at least one actuator element.

In this embodiment, sonic vibrations of the at least one actuator element are transferred to or induced in the inner housing comprising the chamber, while the outer housing serves as the support structure supporting the at least one actuator element.

In this manner, the outer housing can be of more rigid construction in particular of a construction for meeting explosion safety requirements, compared to the inner housing, which may be of a much less rigid and more flexible construction, such that an acoustic pressure can be generated in the chamber as disclosed above, however requiring less powerful actuators than required for inducing sonic vibrations in the outer housing. In an example, the actuators may be a factor ten or more less powerful.

In an embodiment, for facilitating the induction of sonic vibrations, the inner housing is suspended inside the outer housing and attached to the outer housing by vibration support attachments, such as rubber support attachments, for example.

The solution according to the present disclosure is very advantageously in a filter device for filtering particulate matter from a gaseous fluid stream entering the chamber through an inlet and leaving the chamber through an outlet thereof, wherein the chamber is of an elongated shape, comprising a plurality of elongated filter sleeves, the filter sleeves suspended in longitudinal direction in the chamber, wherein the filter sleeves are arranged for passing a gaseous fluid stream comprising particulate matter entering or charging the chamber through the inlet and leaving or discharging the chamber through the outlet, wherein particulate matter is collected at an outer side of the sleeves in the chamber, the device comprising air jet pulse generators arranged for periodically releasing an air jet through the sleeves, for releasing particulate matter collected at the sleeves into the chamber.

The filter sleeves may be made of a textile mesh or plastics material, for example, comprising an outer wall having openings for passing gas and blocking particulate matter above certain dimensions. By way of a non-limiting example, such as for blocking particles having a diameter larger than <NUM> micron of a fine powder product of about <NUM>-<NUM> gram/m<NUM>.

Released particulate matter may be collected at an outer end of the chamber, such as a funnel shaped end, at a material intake side of the chamber, for example.

In an embodiment of this device, a gas stream generating unit is arranged for generating a cleaning gas stream through the filter sleeves into the chamber, when the at least one actuator element is operated in its cleaning vibrating mode, as disclosed above. The cleaning gas stream, preferably, has a direction of flow through the filter sleeves reversed to a direction of flow of the gaseous fluid stream comprising the particulate matter.

Actuators for inducing sonic vibrations in the housing, i.e. the inner housing of the device, in accordance with the present disclosure, are known and available.

In an embodiment of the present disclosure, the at least one actuator element is a sonic vibration electromechanical transducer element, operating in a direction transverse to the inner wall of the chamber. Such an electromechanical transducer element may be of a piston-and-rod type construction, wherein the rod is engaging the housing, i.e. the inner housing of the device, and the piston is electromechanically excited or driven in a sonic vibrating movement, by an electromagnetic voice coil or the like, accommodated in an enclosure attached to the support structure or the outer housing of the device. Such an electromechanical transducer element can be advantageously controlled by an electronic control unit, operated from a remote site, for example.

In a practical embodiment of the present device, a plurality of spaced apart actuator elements is arranged at various positions outside the chamber. These positions are carefully calculated an selected, using acoustic pressure generating modelling algorithms tuned adjusted to a particular device, for example, for generating a desired acoustic pressure inside the chamber. In such a case, the control unit may be arranged for controlling and setting each actuator element separately.

In an embodiment, the device comprises a plurality of actuator elements, or more particularly, transducers, for example in sets of <NUM> or more, and preferably a set of <NUM>. The frequency of each set is swept independently around an installed resonance frequency (being the frequency at which minimum impedance and minimum phase is achieved) to displace acoustic nodes, ensuring continuous varying constructive interference throughout the cylinder volume. This is in contrast with the situation where the frequency is fixed, having static acoustic nodes (and possibly locations of destructive interference) where no dynamics take place.

By way of example, for each set, the sweeping frequency may be adjusted approximately every <NUM> with steps of <NUM>, with a band of approximately <NUM> around the installed resonance frequency. A full sweep of a set of actuators therefore takes approximately <NUM> seconds and is repeated as a saw tooth. Each set, due to the production process (see table) has its own operational settings.

As an alternative to the saw tooth shaped sweep, the set of actuators may, in an embodiment, also have a sweep with a non-sinusoidal waveforms such as a square wave, triangle wave, pulse wave or cycloid wave. Preferably, the resonance frequency may differ between the sets, whereas the sweep band, sweep step and step interval are equal. The applied voltage and hence power transfer may differ as well, wherein preferably the sets with lower resonance frequency have higher voltages applied to the actuators. In a second aspect of the present disclosure, there is provide a method of operating a device according to the first aspect disclosed above, the device comprising a control unit for controlling excitation of the at least one actuator element in at least one of a first vibrating mode and a second vibrating mode, wherein the first vibrating mode is inducing less strong vibrations than the second vibrating mode, and a gas stream generating unit, arranged for providing, i.e. generating and forcing a cleaning gas stream through the chamber, the method comprising:.

That is, during operation of the device for processing or handling particulate matter, i.e. in the first vibrating mode, an acoustic pressure is generated inside the chamber having an intensity and wave pattern for preventing as much as possible particulate matter from adhering to the inner wall of the chamber. In the cleaning mode, i.e. in the second vibrating mode, an acoustic pressure is generated inside the chamber having an intensity and wave pattern for removing as much as possible material adhered to the inner wall of the chamber, while at the same time a cleaning gas stream is generated for discharging released matter from the chamber.

In an embodiment, the cleaning gas stream is introduced in the chamber for a second period of time subsequent to the first period of time. That is, the cleaning gas stream is continued for a period of time after the at least one actuator element is switched off.

The first time period may, for example, continue for a first time period of <NUM> - <NUM> minutes, dependent on the severity of the matter adhered to the chamber, while the second time period may last for about <NUM> minutes, for example.

The above cleaning and discharging steps may be repeated a few times, for providing an optimum cleaning result, while the direction of the cleaning gas stream through the chamber may be altered, for example. It some applications, however, it should be avoided that released, i.e. dirty adhered material is mixed up with clean particulate matter used for production purposes.

In a third aspect of the present disclosure, a material handling and processing installation is provided, comprising material handling equipment producing particulate matter, the installation comprising at least one device according to the first and second aspect of the present disclosure.

Such an installation, which may be part of a larger production plant, may comprise several devices arranged in accordance with the present disclosure, such as material breaking devices, hammering devices, milling devices and the like for dividing chunks or lumps of material or matter into smaller fractions or particles, such as a fine powder; pneumatic transport line devices, filter equipment for filtering particulate matter from the gaseous fluid stream as disclosed above, and any other material handling devices in which particulate matter may adhere to a wall of a chamber in which the particulate matter is introduced.

In particular an installation arranged for handling and processing dry products, including one of food products, cut tobacco products, mineral products, pharmaceutical products and chemical products, such as plastics, toner, detergents, and the like.

The above-mentioned and other features and advantages of the present disclosure are illustrated in the following description with reference to the enclosed drawings which are provided by way of illustration only and which are not limitative to the present invention.

The present disclosure will now be described in more detail based on non-limitative exemplary embodiments. Throughout the description and in the figures, parts having a same or like construction or functional operation, are indicated by like reference numerals.

<FIG> shows, in a schematic and illustrative embodiment, a device <NUM>, having an housing <NUM> enclosing a chamber <NUM> surrounded by an inner wall <NUM> of the housing <NUM>. The inner wall <NUM> has generally closed and smooth surface, thereby already preventing as much as possible adhesion of particulate matter at the surface of the inner wall <NUM>.

The housing <NUM> and the chamber <NUM>, for example, may have a circle cylindrical elongated shape as shown in <FIG>. In practice, however, the housing and the camber may have any shape, not limited to an elongated shape, and adapted to a particular particulate matter handling and processing operation to be executed the chamber <NUM>.

Reference numeral <NUM> refers to particulate matter charged in the chamber <NUM>, such as food, tobacco, mineral, chemical and pharmaceutical products,.

The device <NUM> comprises an external support structure <NUM> to which actuator elements <NUM> are attached. Although not explicitly shown, it will be appreciated that the housing <NUM> may be suspended in or supported by the support structure <NUM>, or another separate support structure (not shown). The support structure <NUM> may be of any constructional design, and attached to another structure or device and/or directly to the fixed world, for example.

The actuator elements <NUM> engage the housing <NUM> at an outer wall <NUM> thereof, and are arranged for inducing sonic, i.e. ultrasonic vibrations in the housing <NUM> and the chamber <NUM>, resulting in acoustic pressure wave patterns <NUM> along the inner wall <NUM> of the chamber <NUM>, as illustratively shown in <FIG>.

In the embodiment shown, the actuator elements <NUM> are sonic vibration electromechanical transducer elements, of a linear type, having an actuator rod <NUM> to which an engagement plate <NUM> connects, shaped in accordance with the shape of the outer wall <NUM>, for optimally acting on the housing <NUM> for inducing the vibrations therein. In operation, the actuator rod <NUM> vibrates in longitudinal direction thereof, transverse to the outer wall <NUM> of the housing <NUM>, i.e. transverse to the inner wall <NUM> of the chamber <NUM>, as indicated by a double arrow <NUM>. The actuator rod <NUM> is driven by an electromagnetic driver, voice coil, or the like, accommodated in an enclosure <NUM>, fixed to the support structure <NUM>.

The actuator element <NUM>, i.e. the driving coil thereof, is excited under the control of an electronic controller or control unit <NUM>, such as microcomputer or microprocessor operated controller, via wired <NUM>, <NUM> or wireless connections (not shown).

The controller <NUM> is arranged operating at different modes of vibration for providing different grades and patterns of acoustic pressure <NUM> inside the chamber <NUM>, by controlling the intensity of the vibrations performed by the actuator element <NUM>, and/or the vibration frequency. The controller <NUM> is in particular arrangement for controlling each actuator element <NUM> separately and independently and/or for superimposing a modulation at the vibrations of the actuator rod <NUM>, thereby modulating the vibrations generated in one or more of strength or intensity, frequency and phase.

The controller <NUM> is in particular arranged for exciting the actuator elements <NUM> in a first vibrating mode, applied when the chamber <NUM> is charged with particulate matter <NUM>, and a second vibrating mode, applied when the particulate matter <NUM> is discharged from the chamber <NUM>. The first vibrating mode corresponds to an intensity and/or pattern of the an acoustic pressure <NUM> in the chamber for bringing the particulate matter <NUM> alongside the inner wall <NUM> in state of turbulence, thereby preventing or impeding particles in the chamber <NUM> from contacting the inner wall <NUM> of the chamber <NUM>. The second vibrating mode is characterized by a stronger vibration intensity compared to the first vibrating mode and, if applicable, an acoustic pressure pattern in the chamber <NUM> for removing particulate matter caked, lumped or otherwise collected at and adhered to the inner wall <NUM>.

Explicit values of intensity or strength, frequency, and mutual phase differences between acoustic pressure waves generated in the chamber <NUM> by various actuator elements <NUM>, depend, among others, on mechanical parameters like the size, thickness, weight, and type of housing material, etc., setting a resonance frequency of the housing, and the number and type of actuators used and there position in a particular embodiment. In practice, the vibrations may cause a deflection of the housing <NUM> in the micron range.

The position of the actuators <NUM> in respect of the housing <NUM> may be calculated and determined using position determining algorithms, against the background of one or more of providing optimum performance, high efficiency, and less operational costs, such as less energy consumption.

For the purpose of the present disclosure, other types of actuator elements may be used, such as rotary electric motor driven vibration actuator, dimensioned to provide sufficient vibration power. In practical embodiments, for example when handling or processing particulate matter for chemical or foodstuff products the housing <NUM> of the device <NUM> may be closed at both ends, arranged as material intake and material discharge end, respectively, comprising valves, mixing and other handling equipment, for example. It is further noted that the elongated housing <NUM> may extend in a vertical direction, for example.

<FIG> shows another embodiment of a device in accordance with the present disclosure, comprising a closed elongated housing <NUM>, defining an elongated chamber <NUM>, enclosed by an inner wall <NUM> of the housing <NUM>. For processing a gaseous fluid stream comprising particulate matter, the chamber <NUM> is provided, at one end thereof, with an intake or inlet <NUM> for receiving the gaseous fluid stream, indicated by arrow <NUM>, and at an opposite end thereof, with an outlet <NUM> for discharging gas having less particulate matter, indicated by arrow <NUM>, compared the gaseous fluid stream <NUM>, for example.

The device <NUM> further comprises a gas stream generating unit <NUM>, such as a fan or other device, for generating and forcing a cleaning gas stream <NUM> through the chamber <NUM> when the actuator elements <NUM> are excited in the above mentioned second vibrating mode, for releasing particulate matter adhered to the inner wall <NUM>. For example, a stream <NUM> of air or an inert gas.

The thus generated cleaning gas stream <NUM> has flow capacity and speed for transporting the released particulate matter out of the chamber <NUM> at the inlet <NUM>. The gas stream generating unit <NUM> may be operated in a suction mode for creating a low pressure or vacuum in the chamber <NUM> and/or in blowing mode for forcing the cleaning gas stream through the chamber by creating an over-pressure in the chamber <NUM>.

The cleaning gas stream <NUM> preferably flows through the chamber <NUM> in a direction opposite at the direction of the gaseous fluid stream <NUM> charging the chamber <NUM> with particulate matter, as illustrated in <FIG>. Alternatively, the cleaning gas stream may flow in a same direction as the gaseous fluid stream <NUM> through the chamber <NUM>, dependent at what end of the chamber <NUM> the released particle matter has to be discharged.

<FIG> shows a device <NUM> in a further embodiment of the present disclosure, comprising an outer housing <NUM> and an inner housing <NUM> arranged inside the outer housing <NUM>. The inner housing <NUM> encloses chamber <NUM>, like the any of the chambers <NUM> or <NUM> disclosed in <FIG>, respectively. The inner housing <NUM> is suspended at the outer housing <NUM> by suspension elements <NUM>, such as rubber rings, bearings, or other support attachments.

The actuator elements <NUM> with their enclosures <NUM> are supported by supports <NUM> forming part of or are separately attached to the outer housing <NUM>. In this embodiment, the outer housing <NUM> advantageously provides the support structure supporting the actuator elements <NUM>. This is in general possible, as in the device <NUM> the outer housing <NUM> can be of more rigid construction, in particular of a construction for meeting explosion safety requirements, compared to the inner housing <NUM>, which may be of a much less rigid and more flexible construction, and in which sonic vibrations are induced by the actuator elements <NUM>, engaging the inner housing through a passage <NUM> in the outer housing <NUM>, such that an acoustic pressure pattern <NUM> can be generated in the chamber <NUM> as disclosed above with reference to <FIG>.

In this embodiment, less powerful actuator elements <NUM> may be used than required if same had to engage the outer housing <NUM> for inducing sonic vibrations, such as with the device <NUM> of <FIG>. It will be appreciated that in a device <NUM> designed to meet explosion safety requirements, the supports <NUM> and the actuator elements <NUM> are designed accordingly.

It will be appreciated that the device <NUM> may comprise a gas stream generating unit <NUM>, such as a fan or other device, for generating and forcing a cleaning gas stream <NUM> through the chamber <NUM>, as disclosed above with reference to <FIG>.

An operation method of a device <NUM>; <NUM>; <NUM> according to the present disclosure, comprising a controller <NUM> and a gas stream generating unit <NUM>, is illustrated by the flow chart diagram <NUM> of <FIG>. In this diagram, steps follow each other in a direction from the top to the bottom of the figure, unless indicated by a respective arrow.

In a first step <NUM>, "Charging chamber with particulate matter", the device is subjected to a material processing or handling by which particulate matter is introduced in the chamber <NUM>; <NUM>; <NUM>. This can be any of breaking, milling, hammering and the like of chunks, lumps, fibers or particulates, or filtering out particles suspended in a gaseous fluid stream <NUM> such as food, tobacco, mineral, chemical and pharmaceutical particulate matter products. In this phase of the operation, the actuator elements <NUM> are excited by the control unit <NUM> in a first vibrating mode, having an intensity and/or providing an acoustic pressure wave pattern <NUM> in the chamber <NUM>; <NUM>; <NUM> for preventing as much as possible particulate matter from adhering to the inner wall <NUM>; <NUM>; <NUM> of the chamber <NUM>; <NUM>; <NUM>, i.e. step <NUM>, "Operate actuators in first vibrating mode".

When the particulate matter processing or handling is terminated in the chamber <NUM>; <NUM>; <NUM>, i.e. step <NUM>, "Discharge particulate matter from chamber", for an effective cleaning of the chamber <NUM>; <NUM>; <NUM> from particulate matter still adhered to the inner wall <NUM>; <NUM>; <NUM> of the chamber <NUM>; <NUM>; <NUM>, the control unit <NUM> is operated in a second vibrating mode, during a first predetermined period of time, such as <NUM>-<NUM> minutes, for example, i.e. step <NUM>, "Operate actuators in second vibrating mode".

At the same time, or a few minutes before or after the start of the second vibrating mode, a cleaning gas stream <NUM> is introduced and forced through the chamber <NUM>; <NUM>; <NUM>, for example in opposite direction of a flow direction of a gaseous fluid stream <NUM> in the chamber <NUM>; <NUM>; <NUM>, by a gas stream generating unit <NUM>, i.e. step <NUM>, "Generate cleaning gas stream in chamber".

In this cleaning mode, i.e. in the second vibrating mode, an acoustic pressure is generated inside the chamber <NUM>; <NUM>; <NUM> having an intensity and wave pattern for releasing as much as possible material adhered to the inner wall <NUM>; <NUM>; <NUM> of the chamber <NUM>; <NUM>; <NUM>, while the cleaning gas stream is dimensioned for discharging released adhered matter from the chamber <NUM>; <NUM>; <NUM>.

The cleaning gas stream <NUM> is introduced in the chamber <NUM>; <NUM>; <NUM> for a second period of time, and may be continued for a period of time after excitation of the actuator elements <NUM> is stopped, such as for about <NUM> minutes, for example.

The above cleaning steps <NUM>, <NUM> may be repeated a few times, for providing an optimum cleaning result, while the direction of the cleaning gas stream <NUM> through the chamber <NUM>; <NUM>;<NUM> may be altered, for example, i.e. decision step <NUM>, "Repeat", result "Yes". Otherwise the operation is terminated and a new or different batch may be processed by the device, i.e. decision step <NUM>, "Repeat", result "No".

The solution according to the present disclosure is very advantageously in a filter device for filtering particulate matter from a gaseous fluid stream, such as shown in <FIG>.

The filter device <NUM> is of the type as shown in <FIG>, comprising a cylindrical outer housing <NUM> and a cylindrical inner housing <NUM>, suspended by suspension elements <NUM> in the outer housing <NUM>, and defining a chamber <NUM> having an inner wall <NUM>. The outer chamber <NUM>, the inner housing <NUM> and the chamber <NUM> are of an elongated shape, comprising a plurality of elongated filter bags, hoses or generally called sleeves <NUM>. The filter sleeves <NUM> are suspended in longitudinal direction in the chamber <NUM> from a filter division plate <NUM>, arranged at an upper end <NUM> of the chamber <NUM>, viewed in the plane of the drawing. The filter sleeves are support at a lower end <NUM> of the chamber <NUM> by a filter support plate <NUM>.

The filter division and support plates <NUM>, <NUM> extend across the entire cross section of the chamber <NUM>. The filter sleeves are open at the upper end <NUM> and closed at the lower end <NUM> of the chamber, and are arranged for passing a gaseous fluid stream comprising particulate matter entering or charging the chamber <NUM> through an inlet <NUM> at the lower end of the chamber <NUM> and leaving or discharging the chamber <NUM> through an outlet <NUM> at the upper end <NUM> of the chamber <NUM>.

The filter bags, hoses or sleeves <NUM> may be made of a textile mesh or plastics material, for example, comprising an outer wall having openings for passing gas and blocking particulate matter above certain dimensions, such as for blocking particles having a diameter larger than <NUM> micron.

In operation, a gaseous fluid stream comprising particulate matter entering the filter device <NUM> via the inlet <NUM> is forced into the chamber <NUM> via openings in the filter support plate <NUM>. The gaseous fluid stream cannot escape the chamber <NUM> at the upper end <NUM>, as the chamber <NUM> is closed at this end by the filter division plate <NUM>, such that the gaseous fluid stream is forced through the sheath of the sleeves <NUM>. As a result, particulate matter from the gaseous fluid stream is collected at an outer side of the sleeves <NUM> facing the chamber <NUM>. The gaseous fluid stream leaving the device <NUM> through the outlet <NUM> is also called the 'clean gas stream' at the 'clean filter end', as this gas stream is as much as possible free from particulate matter. The gaseous fluid stream entering the device <NUM> at the inlet <NUM> is also called the 'dirty gas stream' at the 'dirty filter end'.

The device <NUM> further comprises air (or gas) jet pulse generators <NUM> arranged outside the chamber <NUM> and connected to the open end of the sleeves <NUM>, for periodically releasing an air jet or a jet of an other gas through the sleeves <NUM>, thereby shaking the sleeves, for releasing particulate matter collected at the outside of the sheath of the sleeves <NUM>. This released particulate matter is collected at the funnel shaped part <NUM> at the lower end <NUM> of the chamber <NUM>. Air or an inert gas, for example, is supplied to the jet pulse generators <NUM> via a pipe or line <NUM> and a controlled valve <NUM>. Particles collected in the funnel shaped part <NUM> can be discharged via a respective product discharge valve <NUM>, for example. Optionally, a hammering device <NUM> may engage the funnel shaped part <NUM>, supporting discharge of particle from the device <NUM>.

In accordance with the present disclosure, actuator elements <NUM> engage the inner housing <NUM> and may be operated as elucidated above, for at least one of impeding adhesion of particulate matter at the inner wall <NUM> during filter operation of the device <NUM>, and cleaning the chamber <NUM> from adhered particles. Released adhered particles may be removed from the device at the lower end <NUM> of the chamber <NUM>, for example via the product discharge valve <NUM>.

<FIG> shows, on an enlarged scale, part of the device <NUM> at the upper end <NUM>. The actuator elements <NUM> are supported and fixed to the outer housing <NUM> by support flanges <NUM>. The suspension elements <NUM> may comprise rubber rings, bearings, or other support attachments.

Although not explicitly shown, the inlet <NUM> may also be located at the upper end <NUM> of the right hand side of the device <NUM> and extending through the filter division plate <NUM> into the chamber <NUM> at the upper end.

At the inlet <NUM> or a separate inlet at the funnel part <NUM>, a gas stream generating unit, not shown, may connect, for generating and forcing a cleaning gas stream from the outlet <NUM>, through the filter sleeves <NUM> and the chamber <NUM>, when the actuator elements <NUM> are operated in the cleaning vibrating mode, as disclosed above, by creating a low pressure or vacuum in the chamber <NUM>, for example.

The device <NUM>, in an embodiment thereof, may have a length of <NUM>-<NUM> meters and a diameter of <NUM>-<NUM> meters, for example, and a weight of <NUM>-<NUM> tons, for example. the inner housing may be made of stainless steel or the like, for example.

<FIG> illustrates an installation <NUM> at a production plant for processing and handling dry products, including one of food products, cut tobacco products, mineral products, pharmaceutical products and chemical products, such as plastics, toner, detergents, and the like, suspended in a gaseous fluid stream, such as air or a gas.

The installation comprises a filter device <NUM>, an inlet line <NUM> connecting to the inlet <NUM> of the device <NUM>, for feeding a gaseous fluid stream comprising particulate products to be filtered into the filter device <NUM>. A product discharge line <NUM>, connecting to the product discharge valve <NUM>, and a main gas discharge line <NUM>, operated by a main fan <NUM>, and connected to the outlet <NUM> of the filter device <NUM>, for extracting a clean gaseous fluid stream from the filter device <NUM>, by creating a low pressure or vacuum in the chamber <NUM>.

The installation <NUM> further comprises an auxiliary gas or ventilation line <NUM>, connected at the funnel shaped part <NUM> at the lower end of the filter device <NUM>, and via the main gas discharge line <NUM> to the outlet <NUM>. The auxiliary ventilation line <NUM> is operated by an auxiliary fan <NUM>, through an intermediate ventilation filter <NUM>, and operating as a gas stream generating unit, for forcing a cleaning gas stream through the filter device, by creating a low pressure or vacuum in the chamber <NUM>. This, to discharge released adhered particle from the filter device in the cleaning mode of the actuator elements, as disclosed.

Reference numeral <NUM> refers to a so-called silencer, and reference numerals <NUM> and <NUM> indicate float control valves. Unit <NUM> is an explosion vent. Reference numerals <NUM> and <NUM> refer to a sprinkler installation in the filter device <NUM>. For clarity sake, the actuator elements <NUM> and the control unit <NUM> are not shown. For the purpose of the present disclosure, exemplary power ratings of the actuators <NUM> may range from about <NUM> W to about <NUM> kW or even up.

Those skilled in the art will appreciate that the number of actuator elements used in a particular device may vary and is not limited to two, as shown in the exemplary embodiments.

The solution according to the present disclosure is applicable to any type of device used in handling and processing of particulate matter, such as material breaking devices, hammering devices, milling devices, filter devices, as well as pneumatic transport line devices and any other material handling devices in which particulate matter may adhere to a wall of a processing chamber charged with particulate matter.

Claim 1:
A device, comprising a housing enclosing a chamber surrounded by an inner wall of said housing, arranged for introducing particulate matter in said chamber, said device having an external support structure supporting at least one actuator element arranged for inducing sonic vibrations in said housing and said chamber, thereby providing at least one of impeding adherence of particulate matter at said inner wall of said chamber and releasing particulate matter adhered to said inner wall of said chamber, characterised in that said sonic vibrations are one or more of a frequency range from <NUM>-<NUM>, <NUM>-<NUM> and <NUM>-<NUM>.