WO2011021185A1

WO2011021185A1 - Device, system and method for dislodging deposits

Info

Publication number: WO2011021185A1
Application number: PCT/IL2010/000658
Authority: WO
Inventors: Yuri Ass; Gennadi Kabishcher; Oded Rose
Original assignee: Flow Industries Ltd
Current assignee: Flow Industries Ltd
Priority date: 2009-08-18
Filing date: 2010-08-16
Publication date: 2011-02-24
Anticipated expiration: 2012-02-18
Also published as: IL200467A0; CN101992198A

Abstract

A system and method for generating controlled flow of aggregated particulate matter. The system includes a high pressure gas device adapted for sudden release of high pressure compressed gas into a vessel which exposes aggregated matter within the vessel to separation forces causing their separation and facilitating their flow.

Description

DEVICE, SYSTEM AND METHOD FOR DISLODGING DEPOSITS

FIELD OF THE INVENTION

The present invention relates, generally, to a device and system for dislodging accreted deposits from a vessel and a method for monitoring the rates of dislodgement therefrom.

BACKGROUND OF THE INVENTION

Problems often arise in relation to the various vessels and containers used for the handling and storage of particulate solids. These vessels and/or containers include but are not limited to, bins, tanks and bunkers. Their shapes vary and include those having square or rectangular cross-section and those with flat, pyramidal or dished bases.

A common problem occurring in solid handling vessels is the accretion of paniculate solids which eventually gives rise to reduced flow through the vessel or, in extreme cases, to complete blockage of the vessel.

In more serious cases of agglomeration, the flow from a vessel is partially or totally restricted by bridging of solids across the vessel outlet. Another similar problem is referred to as "rat-holing," which also results in restricted flow from a vessel. When a severe build up of accumulated solids occurs, specialized apparatus is generally required to remove the build-up.

There are known in the art mechanical methods for solving problems of undesired accumulation of solids. By way of example, where an undesirable accumulation of particulate matter is easily accessible, a hammer and chisel (manual or pneumatic) may be used to fracture and remove the agglomerated particles.

In the case of closed vessels with restricted access, there are several known cleaning methods available. One method utilizes a device commonly referred to in the art as a "whip." This device is pneumatically or hydraulically driven, and consists of a cutting head supported from the roof opening of a vessel." The cutting head rotates rapidly so that flail chains attached to the head repeatedly strike the layer of accumulated material while the head is progressively translated upward or downward within the vessel. This process is generally slow and rather cumbersome, and often poses a risk of damage to the vessel being treated.

Other devices well known in the art for preventing or removing build-up of solids in flow through systems are air cannons and vibrators. Air cannons are, however, only moderately efficient for breaking up bridging and ineffective for overcoming rat-holing. Vibrators are only minimally effective for overcoming both bridging and rat-holing.

Gas impulse devices which prevent or remove aggregated particles by disaggregating them are also known. Generally, in this case, the device is lowered into a vessel in the vicinity of agglomerated material. Often the particulates, aggregated or separated, clog, at least in part, the gas discharge ports of these devices. These ports serve as the point of exit of the impulse producing gas from the device into the vessel. Such partial or total blockages lead to a loss of energy and the process of disaggregating particles becomes inefficient. Additionally, none of the above apparatuses including gas impulse devices are used to disaggregate accreted or agglomerated particles so that they can be made to flow at a predetermined desired rate.

SUMMARY OF THE INVENTION

The present invention seeks to provide a device, system and method for more effective cleaning and maintenance of storage, transport and handling vessels. More specifically, the present invention is directed to providing a device, system and method for loosening and removing accretions of accumulated particulate solids from the vicinity of a vessel wall, particularly in a non-liquid environment. Additionally, the present invention provides a system and method for automatically and/or manually controlling the rate of discharge of dislodged and disaggregated particles from an outlet aperture of a vessel.

In seeking to achieve the above objectives, and in accordance with a preferred embodiment of the present invention, a suitable device, for example, as described in the Applicant's U.S. Patent No. 6250388, for generating shock-waves or gas impulses is provided and positioned in an enclosure member fastened to a vessel wall adjacent to and abutting an opening in the wall. The vessel contains an accretion of solids which needs to be removed or made to flow. The device is operated so as to produce a series of shock waves or impulses which are propagated through the vessel, thereby to loosen and progressively separate the agglomerated solids from surface or surfaces of the vessel to which they are attached, or from a region or regions of the vessel where they have accumulated. The rate of efflux from an outlet aperture of the vessel may be measured and a system is provided which allows for monitoring and controlling the rate of efflux.

There is thus provided, in accordance with one aspect of the invention, a system for generating a controlled flow of aggregated particulate matter. The system comprises a high pressure gas device adapted for sudden release of high pressure compressed gas in the vicinity of a vessel according to a set of operating parameters, thereby exposing aggregated particulate matter found in the vessel to separation forces causing separation of the particulates and facilitating flow thereof. The system also includes a measuring apparatus for monitoring the flow rate of the flowing separated particulates by measuring a flow rate related property of the particulates and a control system in operative communication with the high pressure gas device for controlling firing thereof and for generating shock waves therewith. The control system is also in operative communication with the measuring apparatus for monitoring the flow rate of the separated particulates. The control system is operative to compute a set of updated operating parameters based on the measured flow rate and for use in the operation of the device. Finally, the system includes a display for displaying at least the updated operating parameters computed by the control system.

Additionally, in accordance with an embodiment of the present invention, the system further comprises an input device in operative communication with the high pressure gas device for generating shock waves whereby a user provides the updated operating parameters displayed on the display to the gas device via the input device, thereby adjusting the rate of firing of the device and the flow rate resulting therefrom.

According to an embodiment of the present invention, the updated operating parameters calculated by the control system to adjust the rate of firing of the high pressure gas device and provided by the control system to the device, thereby to adjust the resulting flow rate to a preselected flow rate.

According to another embodiment of the present invention, the system is a dual mode operating system including a user operated mode and a control system directed mode. The system further comprises an input device for use in the user operated mode. The input device is in operative communication with the high pressure gas device and the user provides the updated parameters displayed on the display to the high pressure gas device, thereby to adjust the rate of firing of the device and the flow rate resulting therefrom. The control system in the control system directed mode is in electronic communication with the high pressure gas device whereby the updated operating parameters computed by the control system are supplied to the high pressure gas device, thereby to adjust the rate of firing of the device and flow rate resulting therefrom.

In the present invention, the set of operating parameters includes the pressure of the compressed gas supplied to the device, the frequency of the firings in each firing cycle and the duration of the firing cycle.

In a variation of an embodiment of the present invention, the display further displays the previous operating parameters and the flow rate resulting therefrom.

In another embodiment of the present invention of the system, the system further includes an enclosure member. The member has an at least partially open end and the high pressure gas device is positioned therein. The enclosure member is adapted to be fastened to the vessel, generally in a region of an aperture in a wall of the vessel. The at least partially open end of the enclosure member essentially abuts the aperture of the vessel so that the shock waves generated by the high pressure gas device enter the vessel through the aperture after traveling within the enclosure member.

In yet another embodiment of the present invention, the system further includes one or more shock absorbing elements in mechanical connection with the enclosure member and the high pressure gas device. The one or more shock absorbing elements absorb the shock of the gas impulses generated by the device.

In still another embodiment of the present invention, the high pressure gas device further includes one or more discharge ports. The discharge ports are angled in the general direction of the vessel wall so that the discharged gas travels in the general direction toward the wall of the vessel when it exits the one or more discharge ports. Energy losses are thereby reduced when the gas is emitted from the discharge ports so angled.

In a further embodiment of the system, the high pressure gas device is operative at a pressure range of about 10 to about 250 bars, and more preferably at a pressure range of about 50 to about 150 bars. In yet another aspect of the present invention, there is provided a second system for generating a controlled flow of aggregated particulate matter. The system comprises a high pressure gas device adapted for sudden release of high pressure gas in the vicinity of the vessel according to a set of operating parameters, thereby to expose the aggregated particulate matter found in the vessel to separation forces causing their separation and facilitating flow thereof. The system also includes an enclosure member having an at least partially open end with the high pressure gas device being positioned in the member. The enclosure member is adapted to be mechanically fastened to a wall of the vessel, generally in a region of an aperture in the wall, with the at least partially open end of the enclosure member essentially abutting the aperture. The gas borne shock waves generated by the high pressure gas device enter the vessel through the aperture after traveling within the enclosure member.

In yet another embodiment of this second system, the system further includes one or more shock absorbing elements in mechanical connection with the enclosure member and the high pressure gas device. The one or more shock absorbing elements absorb the shock of the gas impulses generated by the high pressure gas device.

In another embodiment of this second system, the device further includes one or more discharge ports. The discharge ports are angled in the general direction of the vessel wall so that the discharged gas travels in the general direction toward the wall when it exits the discharge ports. Energy losses are reduced when gas is emitted from the discharge ports so angled.

In a yet another embodiment of the second system, the system further comprises a measuring apparatus for monitoring the flow rate of the flowing separated particulates by measuring a flow-related property of the particulates. Additionally, the system comprises a control system in operative communication with the high pressure gas device for controlling the firing thereof and for generating shock waves. The control system is also in operative communication with the measuring apparatus for monitoring the flow rate of the separated particulates. The control system is operative to compute a set of updated operating parameters based on the measurement of the flow rate and for use in the operation of the high pressure gas device. Additionally, the system includes a display for displaying the updated operating parameters computed by the control system. In still another embodiment of this second system present invention, the updated operating parameters are calculated to adjust the flow rate to a pre-selected flow rate.

In a further embodiment of the second system the high pressure gas device is operative at a pressure range of about 10 to about 250 bars, and more preferably at a pressure range of about 50 to about 150 bars.

In yet another aspect of the present invention, there is provided a method for generating a controlled flow of aggregated particulate matter. The method includes a number of steps. The first step is the step of firing a high pressure gas device adapted for sudden release of high pressure compressed gas in the vicinity of a vessel, containing aggregated particulates, the firing being effected according to a set of preselected operating parameters. The emitted shock waves and high velocity gas flow separate the aggregated particulates causing them to flow through an outlet aperture of the vessel. This is followed by the step of measuring a flow-related property of the flowing particulate aggregates. This is succeeded by the step of providing the measured flow-related property of the flowing particulates to a control system. The control system correlates the flow-related property with a flow rate and calculates a set of updated operating parameters based on the correlated flow rate of the flowing particulates. The updated parameters are used for further firings of the high pressure gas device, thereby altering the flow rate of the separated particulates. Finally, the step of displaying displays the updated operating parameters on a display so that they can be used to modify the operating parameters of the high pressure gas device for future firings thereof.

In an embodiment of the method of the present invention, the method further comprises a step of providing the updated operating parameters to the high pressure gas device by a user and having the user subsequently fire the device.

In yet another embodiment of the method, the method further comprises a step of providing the updated operating parameters to the high pressure gas device via the control system in electronic communication with the high pressure gas device and thereafter having the control system fire the device.

In still another embodiment of the method, the method further comprises a step of selectably using either a user to provide the updated operating parameters to the high pressure gas device and having the user subsequently fire the high pressure gas device or by providing the updated operating parameters to the device via the control system which is in electronic communication with the high pressure gas device to provide the updated operating parameters to the high pressure gas device and thereafter having the control system fire the device.

In the embodiments of the method, the operating parameters include the pressure of the compressed gas supplied to the high pressure gas device, the frequency of the firings in each predetermined firing cycle and the duration of the predetermined firing cycle.

In still another embodiment of the method, the method further includes a step of establishing a correlation between the operating parameters of the high pressure gas device and the flow rate of the particulates.

In another aspect of the present invention, there is provided a method for generating a controlled flow of aggregated particulate matter. The method comprises the steps of:

firing a high pressure gas device adapted for sudden release of high pressure compressed gas in the vicinity of a vessel, the firing being effected according to a set of preselected operating parameters and the firing stimulating particulate flow in the vessel so that it egresses through an outlet aperture of the vessel;

monitoring the flow rate of the solid particulates in the vessel or at the outlet aperture of the vessel; and

adjusting the operating parameters of the device so that the flow rate of the particulate matter corresponds to a predetermined desired flow rate.

In an embodiment of this second method, the method further includes a step of displaying the updated operating parameters on a display so that they can be used to adjust the operating parameters of the device for future firings thereof. BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be more fully understood and its features and advantages will become apparent to those skilled in the art by reference to the ensuing description, taken in conjunction with the accompanying drawings, in which:

Fig. IA illustrates a schematic cross-sectional view of a vessel having an accretion of a substance deposited against an interior wall thereof (prior art);

Fig. IB illustrates a schematic cross-sectional view of a vessel wherein particulate solids form a "bridging" over the vessel outlet (prior art); Fig. 1C illustrates a schematic cross-sectional view of a gas impulse device fixed within the wall of a vessel and extending into the accreted and/or agglomerated solid particles which must be removed (prior art);

Fig. 2A is a schematic cross-sectional view of a gas impulse device in its charging mode encased in an enclosure member which is fastened to the wall of a vessel according to an embodiment of the present invention;

Fig. 2B is a schematic cross-sectional view of a gas impulse device in its discharging mode encased in an enclosure member which is fastened to the wall of a vessel according to an embodiment of the present invention;

Fig. 3 is a side cross-sectional view of the discharging gas impulse device shown in Figs. 2A-2B fastened to the wall of a vessel and including an enclosure member and shock absorbing elements according to an embodiment of the present invention;

Fig. 4 is a block diagram representation of a system for generating gas-borne shock waves in a vessel containing agglomerated particulates which require disaggregation and monitoring the rate of dislodgement of the accreted substance in the vessel, in accordance with an embodiment of the invention;

Fig. 5A is a flow chart representation of a first embodiment of a method for monitoring the rate of dislodgement of an accretion of a substance deposited on a wall of, or in, a vessel;

Fig. 5B is a flow chart representation of a second embodiment of a method for monitoring the rate of dislodgement of an accretion of a substance deposited on a wall of, or in, a vessel in accordance with an embodiment of the present invention; and

Fig. 5C is a flow chart representation of a third embodiment for monitoring the rate of dislodgement of an accretion of a substance deposited on a wall of, or in, a vessel in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

The device, system and method described below relate to the use of gas impulse devices for loosening accumulated solid particles and for cleaning the interior surfaces of vessels. The cleaning process is achieved by supportively positioning and fastening one or more gas impulse devices on the exterior surface of the vessel in question in close proximity to accumulated solids and by supplying compressed gas to the device for repeatedly generating gas-borne shock waves. The gas impulse device is positioned in an enclosure member which is fastened to the exterior of the vessel generally abutting an opening in the wall of the vessel. Repeated shock waves, and the air flow following the shock waves, impinging on the accumulated solid particles and on the adjacent interior surface of the vessel have the effect of shaking, vibrating and, hence, loosening the solids. These fixed devices may be operated either periodically when the accumulation of accreted particles becomes unacceptable or on an ongoing or scheduled basis to prevent any build-up of solids.

Vessels for storing or holding substantially dry, particulate materials, include silos, hoppers, bins, and tanks among others. These vessels are potentially subject to accretion of agglomerated solid material, as a consequence of the particles being inherently cohesive, being compactable or being moist. Other solid material handling equipment, such as dust separating cyclones, dust filters, electrostatic separators, ducting, chimneys, cooler towers, preheater cyclones, piping, and even tipper-trucks, to mention a few, are also subject to such an accretion problem.

The gas impulse device discussed herein may also be called any of the following without any distinction between them: a gas impulse device, an impulse generating device, a gas impulse generating device, a device for generating gas-borne shock waves, a high pressure compressed gas device adapted for sudden release of high pressure gas, a high pressure compressed gas device or a high pressure gas device.

Before explaining several embodiments of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.

Referring now to Fig. IA (prior art), there is depicted a schematic, cross- sectional view of a vessel 101 having an accretion of a substance generally referenced 104, deposited against a junction formed between a cylindrical portion 102 of the vessel wall and a lower conical section 103 thereof. Such accretions often occur in regions of a vessel characterized by reduced material movement such as corners, irregularities in the surface wall, contour changes to the vessel surface, and joins in the vessel such as the junction between a vertical wall and an inverted pyramidal or conical base. Additionally, depicted in this figure are multiple gas impulse devices 108, suspended from a supporting mechanism 105, supporting frame 106 and suspending cables 107 such that the gas impulse devices are positioned proximate to the accretion of solid material on the interior walls. Such an arrangement is generally used for, but not limited to, large vessels which, for example, are filled and then emptied of their contents and require substantial clearing of any accumulated material prior to being refilled.

Referring now to Fig. I B (prior art), there is illustrated a schematic, cross- sectional view of a vessel 201 whose contents, referenced generally 203, form a "bridging" 204 over the vessel outlet aperture 202 in the vicinity of a lower, tapered section of the conical wall 206 of the vessel 201. This is a consequence of agglomeration, that is, the accumulation of compacted, cohesive particulate material. Many particulate materials do not flow freely especially in the presence of any moisture, or if the material has a high angle of repose due to physical characteristics of the solid material, or if the material is naturally compactable. Further, there are materials which tend to absorb moisture from the atmosphere, from the air, or from another gas that is used in some systems to promote the flow of the solids. Drier materials are generally more free-flowing, and, therefore, do not build up or agglomerate as severely as moist materials. In addition, material which does not tend to agglomerate requires less power to loosen when such build-up does occur. In order to breakdown the bridging agglomerate, for example, but not limited to this technique, one or more gas impulse devices 205 are installed through the conical wall 206 of the vessel 201 near to the an outlet aperture 202. The gas impulse devices are operated to prevent bridging, either on a continuous basis or on a programmed cyclic basis, or, alternatively, are operated specifically when bridging occurs.

In accordance with an embodiment of the invention, gas impulse or shock wave generating devices very similar to the devices disclosed in Applicant's United States Patent 6250388 may be used with the modifications arising from the teachings and disclosure herein. Such a device is commercially available from Prowell Technologies Ltd., Mishor Rotem, Israel. Other suitable gas-blasting devices may also be used, such as Bolt Air Guns marketed by Bolt Technology Corporation, Norwalk CT, USA. These devices are, inter alia, disclosed in US Patent Nos. 4,779,245 and 4,754,443.

These patents describe an air-blasting cartridge comprising a housing subdivided into an inlet chamber and a discharge chamber by virtue of a piston arranged lengthwise along a longitudinal axis of the housing. The inlet chamber communicates with a source of compressed air through an air admission tube, which runs the length of the cartridge through an axial port of the piston. The discharge chamber communicates with the inlet chamber through an annular gap between the air admission tube and the piston. The discharge chamber is adapted to communicate with the surrounding atmosphere at the instant of its discharge, by means of at least one open-ended passage made in the housing close to the inlet chamber, wherein a pressure relief valve is provided at the outlet end of the passage.

After providing high-pressure gas to the gas impulse device, shock waves can be generated. The shock waves transmit impulses between approximately 0.3 and 5 times per second. The shock waves have a frequency in the range of 100 - 1000 Hz, and have a pulse duration of between 1 to 60 msecs. The compressed gas provided to the gas impulse device is provided at a pressure in the range of 1 to 350 bar but generally in the range of 50 to 200 bar.

The shock waves generated by the gas impulse device are the primary cause of the fracturing and cracking of the bulk material. Each of the shock waves is followed by a high velocity gas flow which, when impinging on the bulk material, turns velocity into high pressure and finishes the crushing of the accreted deposits. The exact gas pressure that is provided is in accordance with, and appropriate to, the severity of the accumulation and the agglomeration.

Shock waves impacting material adjacent to the gas impulse device, causes the agglomerated material to progressively break apart, crumble or fracture. The high velocity gas flow following the shock wave finishes crushing the deposits and fluidizes them. It also removes bridging and rat-holing structures in the vessel as well as generally cleans deposits from the vessel walls.

The decision regarding a suitable gas to be utilized in each application depends on the possibility of chemical interaction between the particulate solid material and the gas. Where there is no risk of such interaction, air is preferred for reasons of cost and availability. However, in the presence of oxygen in the air, many finely divided particulate materials present a risk of dust explosions or flammability. Alternative gases for use in such instances include nitrogen or carbon dioxide, although the latter presents a somewhat lower pressure capability.

Reference is now made to Fig. 1C (prior art) where a gas impulse device 200 containing a piston 214 extends through the wall 20 I W of a vessel and into accreted particulate matter 203. When the discharge ports 212 of the gas impulse device 200 are positioned inside vessel 201 , ports 212 are generally buried inside the bulk solid and agglomerated material 203. For gas impulse devices to operate effectively, when gas is released from discharge ports 212 of device 200, the gas needs free space around the device for a shock wave to be generated. Because the aggregated solid or even separated solid material, at least partially and possibly even substantially, blocks or seals the space around device 200, a shock wave can not be generated. This results in low efficiency of the discharged gas stream and device 200.

As a solution to this problem the present invention teaches the enclosure of a gas impulse device in an enclosure member. To obtain the desired operational effect of dislodging the aggregated particulate material in the vessel, it is necessary to release the gas inside the enclosure member. This configuration allows the discharged gas to accelerate inside the enclosure member generating a shock wave near the enclosure member's opening which abuts the vessel wall to which the enclosure member is fastened. The length of the enclosure member is calculated so that the shock wave is generated in the vicinity of the enclosure member's opening generally positioned at the vessel's wall at the end of the enclosure member. It is readily understood that the enclosure member is fastened to a wall of the vessel, substantially adjacent to an aperture in the well.

It can be readily understood that in other embodiments, there may be a plurality of gas impulse devices each of which is positioned in its own enclosure member. Each of the enclosure members is fastened to the vessel at a different point of the wall of the vessel.

Figs. 2A and 2B to which reference is now made, show a gas impulse device constructed according to an embodiment of the present invention. Fig. 2A shows the device in its charging mode while Fig. 2B shows the device in its discharging mode. Fig. 2B shows the device positioned in its operational position in a shock wave enclosure member which is fastened to a wall of a vessel from which accreted and/or aggregated particles are to be dislodged and separated. Figs. 2A and 2B are to be discussed together.

Gas flows into pressurization chamber 391 and inlet chamber 390 simultaneously through openings 380 and 381 of inlet tube 392. Gas enters inlet tube 392 via inlet port 393 from a gas supply (not shown). Because the volume of pressurized chamber 391 is larger than the volume of inlet chamber 390 and/or the opening 380 in inlet chamber 390 is larger than opening 381 in pressurization chamber 391 , pressure builds up faster in inlet chamber 390 than in pressurization chamber 391. This generates a force on piston surface 395 of piston 397 from inlet chamber 390 that is greater than the force exerted on piston surface 396 of piston 397 from pressurized chamber 391. This force pushes piston 397 in the direction of seals 346 and into its charged position (Fig. 2A). Gas is prevented from flowing within the gap G between piston 397 and inlet tube 392 by means of seals 345.

Gas impulse device 300 is positioned in a shock wave enclosure member 314 which typically forms a cylindrical chamber 349, herein also denoted as a shock wave generating chamber, between enclosure member 314 and device 300. Discharge ports 312 are oriented at an angle greater than 90 degrees with respect to device axis XX¹, that is ports 312 are angled in a general direction toward vessel wall 301 W. This allows gas leaving pressurized chamber 391 via discharge ports 312 to enter shock wave generation chamber 349 with minimum energy loss. Such losses would occur if discharge ports 312 were oriented perpendicular to device axis XX' or at an acute angle with respect to device axis XX', that is angled in a general direction away from vessel wall 301 W and in the general direction of inlet port 393. In this latter orientation, gas emerging from ports 312 would have to turn in the direction of vessel wall 301 W and in doing so lose energy. The direction of the flow of the discharged gas is shown in Fig. 2B by arrows.

The angle of discharge ports 312 referred to above in the present invention may range from greater than 90 degrees to less than 180 degrees, preferably between about 135 to 160 degrees. The angle being discussed is shown in greater detail in Fig. 2B and designated there as angle XOD where O is the point on axis XX' intersecting line DO which serves as an axis of discharge port 312.

Shock wave enclosure member 314 consists of a flange 351 , an elongated smooth section 352 and an enlarged thick section 353. The thickness of element 353 allows for the formation of shock wave chamber 349 since element 353 does not allow device 300 to lie flush against elongated section 352.

Typically, enclosure member 314 is elongated and has a hollow cylindrical shape much as a pipe. However, in other embodiments the enclosure member may have other hollow elongated shapes as well, such as hollow elongated octagonal or hexagonal shapes.

By way of contrast to prior art gas impulse devices, device housing 354 includes flange element 360 while housing 382 surrounding pressurized chamber 391 includes flange member 370. When assembled, gas impulse device 300 has a flange part comprising joined flange element 360 and flange member 370 which extends outward from the device's basically cylindrical shape substantially transverse to the long axis XX' of the cylinder.

Shock wave enclosure member 314 is fixed to the vessel, which without intending to limit the invention may be a silo, a hopper, a bin or another type of vessel, at a surface or wall 30 I W of the vessel by flange element 351. This join may be effected by welding, but as can be readily understood by one skilled in the art, other fastening methods may also be used. Gas impulse device 300 is inserted into the shock wave generation enclosure member 314 and is stopped when the flange part consisting of flange element 360 and flange member 370 discussed above reaches enlarged thick section 353 of enclosure member 314.

Reference is now made to Fig. 3 which shows enclosure member 314, with gas impulse device 300 positioned therein, fastened to vessel wall 301 W. Vibrations and waves originating upon discharge of gas impulse device 300 impinge on enclosure member 314 which in turn transmits them to vessel wall 30 I W. This may possibly damage the vessel. To prevent damage to the vessel, shock wave generation enclosure member 314 is fabricated with a flange section 491. Shock absorbers 400 are installed on flange section 491 and with the flange part discussed above, comprised of flange element 360 and flange member 370. In the example shown in Fig. 3, shock absorbers 400 are comprised of a bolt 492, a washer 493, and a polyurethane ring 494 surrounded by a supporting metal washer 496. It should be readily understood by one skilled in the art that the construction of a shock absorbing mechanism may be made in numerous other ways and the mechanism shown in Fig. 3 is not intended to limit the invention. In Figs. 2A to 3, gas impulse device 300 is shown as being positioned within enclosure member 314, and entirely outside of vessel wall 30 IW. In other embodiments, gas impulse device 300 may extend somewhat past vessel wall 30 IW and into the vessel. In such embodiments, device 300 is positioned within enclosure member 314 and discharge ports 312 are positioned outside of vessel wall 301 W. Accordingly, particulates can not block ports 312 when gas is discharged from device 300.

It would be advantageous to be able to monitor and control the flow rate of dislodged and disaggregated particulate solids out of a vessel when flow is stimulated by the gas impulse device and system discussed above. Controlling flow rate allows for better compounding in multi-component compositions such as cements and agriculture feed mixtures. Such solids often agglomerate and accrete in their respective storage vessels. Accordingly, the following system for stimulating solid particulate flow of initially agglomerated and accreted particulates and method for control of particulate flow rate is being provided.

Reference is now made to Figure 4 which shows a block diagram representation of a system for generating high-pressure impulses in a vessel and monitoring and/or controlling the resulting rate of dislodgement of accreted solid material in the vessel.

The system includes a control system 603 comprised of a computer 609 and at least one controller device 608. Computer 609 is in electronic communication via the at least one controller device 608 with a high-pressure gas impulse device 601 , a measuring apparatus 605 which measures a flow-related parameter of the flowing disaggregated particles and a display 607. Gas impulse device 601 may include the gas impulse device and enclosure member discussed above in conjunction with Figs. 2A-3, although in other embodiments other gas impulse device arrangements may also be used. The measuring apparatus may be positioned within or exterior to the vessel in which the accreted particles are located, depending on the flow-related parameter/property or parameters/properties to be measured. A flow-related property may be a property such as weight or height. The change over time of such a property correlates with, if it is not identical to, a flow rate.

In some embodiments, measuring apparatus 605 may be placed within the vessel containing the aggregated particles. In other embodiments, measuring apparatus 605 may be placed adjacent to an outlet aperture of the vessel. In some instances, this placement adjacent to the outlet aperture may be on the inside of the vessel while in other instances it may be adjacent to the outlet aperture but on the outside of the vessel.

Computer 609 of control system 603 calculates new operating parameters based on the measurements obtained by measuring apparatus 605 and provided to computer 609 via the at least one controller device 609. The calculated operating parameters typically, but without limiting the invention, are intended to generate the particulate flow rate out of an aperture of the vessel so that it may, if desired, equal a predetermined flow rate.

The calculated revised operating parameters generated by computer 609 are provided to, and displayed on, display 607. It should be understood that display 607 may display other information as well, for example, and without intending to limit the invention, the measured flow rate and the previous operating parameters that were used to generate the measured flow rate.

In some embodiments, the display 607 may display only the flow-related parameters without displaying the device operating parameters.

In one embodiment, computer 609 provides the calculated operating parameters directly to the gas impulse device 601 through at least one controller device 608 and then instructs the device to periodically fire based on the revised operating parameters.

In another embodiment, there may be an input device (not shown) which can be employed by a user to provide the revised operating parameters to gas impulse device 601. The operating parameters provided by the user are typically those displayed on display 607 and calculated by computer 609.

In yet another embodiment, the user may provide the revised operating parameters to gas impulse device 601 directly. The operating parameters provided by the user are typically those displayed on display 607 and calculated by computer 609.

In still other embodiments, the user may provide revised operating parameters directly, these having been independently determined by the user.

It should be readily understood that more than a single gas impulse device may be used to loosen and/or break apart aggregated particulates, allowing them to flow. Generally, each of these gas impulse devices would be positioned at a different point of the wall of the vessel, each of the points being an aperture in the wall. Fig. 5A, to which reference is now made, is a flow chart of a first embodiment of a method for generating flow of accreted particles in a vessel and for monitoring and controlling the rate of dislodgement of the accreted particles deposited in the vessel or on its walls.

In the flow chart, step 501 indicates the firing of the gas impulse device according to an initial set of operating parameters. These parameters include, but need not be limited to, frequency of firing the gas impulse device in each firing cycle, duration of each firing cycle, and pressure of the compressed gas supplied to the device. In this embodiment, either the user or a control system may initially activate the gas impulse device.

Periodically, or continuously, a measuring apparatus measures 503 the value of at least one parameter related to the particulate flow rate. The measuring apparatus provides 505 the measured value of the at least one measured parameter related to the particulate flow rate to a computer of a control system. The measured parameter may be the weight of material per a defined time period that flows out of an outlet aperture of the vessel. In other instances, the measuring apparatus may measure the depth level of the particulates in the vessel or the depth level of the particles in a collection container located exterior to the vessel near the outlet aperture. These parameters are to be viewed as examples only and not to be viewed as limiting the invention.

The value of the at least one measured flow rate related parameter that has been provided by the measuring apparatus to the computer of the control system in step 505, is used by the computer in step 507 to calculate a new revised set of values for the operating parameters. These revised parameters may adjust the actual flow rate to a predetermined flow rate. A predetermined desired flow rate may be preselected and programmed into a computer of the control system.

The recalculated operating parameters are then provided 509 by the computer via a controller device of the control system to the gas impulse device and the control system automatically fires the gas impulse device using the recalculated revised values of the operating parameters. The recalculated values of the operating parameters may also then be provided 51 1 to a display for presentation. The actual measured flow rate may also be displayed on the display.

The flow chart in Fig. 5A then returns to the step of measuring 503 and steps 503 through 509 and 51 1 are repeated for as long as desired or needed. Fig. 5B, to which reference is now made, is a flow chart representation of a second embodiment of the method for generating flow of accreted particles in a vessel and for monitoring and controlling the rate of dislodgement of the accreted particles deposited in the vessel or on its walls.

In step 501 of the flow chart, the gas impulse device is fired under an initial set of operating parameters. As previously noted, these parameters include, but need not be limited to, frequency of firing the gas impulse device during each firing cycle, duration of each firing cycle and pressure of the compressed gas supplied to the device. In this embodiment, the user fires the impulse generating device and the firing is not automated as it is in the embodiment of Fig. 5A.

Periodically, or continuously, a measuring apparatus measures 503 a value of at least one measured parameter related to the particulate flow rate. The measurement of the value of the at least one flow rate related parameter is provided 505 to a computer of a control system. The computer then recalculates 507 a new revised set of values for the operating parameters. Typically, but without intending to limit the invention, these values are intended to adjust the particulate flow rate to a predetermined flow rate. The predetermined desired flow rate may be preselected and preprogrammed into the computer.

The recalculated values for the gas impulse device's operating parameters are then provided 51 1 by the computer via a control device of the control system to a display and presented thereon. The user then provides 513 the recalculated operating parameters appearing on the display to the impulse device. The user then fires 513 the gas impulse device using the recalculated operating parameters.

The flow chart in Fig. 5B then returns to the step of measuring 503 where steps 503 through steps 513 are repeated as often as required or desired.

In some instances of the second embodiment of the method (Fig. 5B) the user may input his own values for the operating parameters overruling and disregarding those values calculated by the computer.

In another embodiment of the method there are two possible modes of activating, that is, firing, the gas impulse device: the device may be activated in a user firing mode, also denoted herein as a user operated mode, or alternatively, the device may be activated in a control system firing mode, also denoted herein as a control system directed mode. In some embodiments of the user firing mode, the user may input his own values for the operating parameters disregarding those values calculated by the computer of the control system.

The computer makes use of a database library to determine the flow rate and the operating parameters needed for the flow rate to be adjusted to a preselected desired flow rate.

An expression of the form in (I) below can be used to calculate the operating parameters needed to arrive at a desired flow rate. Expression (I) can be written:

v=k_jVP^jNF (I)

where P is the pressure of the gas supplied to the gas impulse device, N is the number of impulses per activation cycle, and F is the number of activation cycles per predefined time period; k is a constant reflecting the shape and other technical characteristics of the vessel, including the material from which the vessel is built; V is the amount of gas released into the vessel per impulse, itself a constant for a specific gas impulse device; i is an exponent that can be a whole or a fractional value depending on the properties of the bulk solids; v is the flow rate, or equivalently, the vessel discharge rate; and j indicates the set of environmental conditions that are held constant during a measurement.

Because V is constant for a specific gas impulse device, expression (I) can be rewritten as expression (II) in the form:

V=K_jP¹NF (II) where K is a different constant but determined under the same set of environmental conditions j.

A database library is created for a specific gas impulse device in a specific material and external environment. Besides the material itself, for example cement or agricultural feedstuffs, the external environmental conditions are held constant for a given library of measurements. These environmental conditions j include, for example and without intending to limit the invention, temperature, humidity. Then a set of measurements are made by varying independent variable P, while holding N and F constant, then changing N and F and holding them constant while again varying P, and repeating for a full range of P, N and F over a given set of constant environmental conditions j. The environmental conditions j are changed, and again independent variables P, N and F are varied as described above. The dependent variable v is measured under all these different conditions for a full range of independent variables N and F and P and for a full range of expected environmental conditions j.

A log v- log P plot, created using, for example, partial least squares (PLS) or recursive least squares (RLS) regression, can be used to determine the values of exponent i and constant K based on measurements of v while varying P, and while holding N and F constant for a series of measurements. Using the known i and K, at a given set of constant environmental conditions j allows a v to be guessed at by using a set of P, N and F from the log-log regression plots.

The above described data treatment is only one of many possible data treatments that can be used and should not be considered as limiting the invention. Others methods of data treatment known to those skilled in the art may also be used.

Reference is now made to Fig. 5C where another embodiment of the method of the present invention is shown. The Figure shows a flow chart representation of a third embodiment of the method for generating flow of accreted particles in a vessel and for monitoring and controlling the rate of dislodgement of the accreted particles deposited in the vessel or on its walls.

In step 501 of the flow chart, the gas impulse device is fired under an initial set of operating parameters. As previously noted, these parameters include, but need not be limited to, frequency of firing the gas impulse device during each firing cycle, duration of each firing cycle and pressure of the compressed gas supplied to the device. In this embodiment, the user fires the impulse generating device and the firing is not automated as it is in the embodiment of Fig. 5 A.

Periodically, or continuously, a measuring apparatus measures 503 a value of at least one measured parameter related to the particulate flow rate. The measurement of the value of the at least one flow rate related parameter is provided 504 to the display, from which a user can monitor the flow rate. Next, a user chooses 506 a new revised set of values for the operating parameters which, without intending to limit the invention, may be used to adjust the particulate flow rate to a predetermined flow rate.

The new values for the gas impulse device's operating parameters are then provided 508 by the user to the gas impulse device through a controller device. The user then fires 510 the gas impulse device using the recalculated operating parameters.

The flow chart in Fig. 5C then returns to the step of measuring 503 where steps 503 through steps 513 are repeated as often as required or desired.

Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.

It will be appreciated by persons skilled in the art that the present invention is not limited by the drawings and description hereinabove presented. Rather, the invention is defined solely by the claims that follow.

Claims

1. A system for generating a controlled flow of aggregated particulate matter, said system comprising:

a high pressure gas device adapted for sudden release of high pressure compressed gas in the vicinity of a vessel according to a set of operating parameters, thereby to expose aggregated particulate matter found in the vessel to separation forces causing separation of the particulates and facilitating flow thereof; and

an enclosure member having an at least partially open end and wherein said high pressure gas device is positioned therein, said enclosure member adapted to be mechanically fastened to a wall of the vessel, generally in a region of an aperture in the wall, with said at least partially open end of said enclosure member essentially abutting the aperture of the vessel so that shock waves generated by said high pressure gas device enter the vessel through the aperture after traveling within said enclosure member.

2. A system according to claim 1 further including at least one shock absorbing element in mechanical connection with said enclosure member and said high pressure gas device, said at least one shock absorbing element absorbing the shock of gas impulses generated by said high pressure gas device.

3. A system according to any one of claims 1 or 2 wherein said high pressure gas device further includes at least one discharge port, said discharge port angled in the general direction of the wall of the vessel so that the discharged gas travels in the general direction toward the wall of the vessel when it exits said at least one discharge port and so that energy losses are reduced when gas is emitted from said at least one discharge port so angled.

4. A system according to any one of claims 1 -3 wherein said high pressure gas device is operative at a pressure range of about 10 to about 250 bars.

5. A system according to any one of claims 1 -3 wherein said high pressure gas device is operative at a pressure range of about 50 to about 150 bars.

6. A method for generating a controlled flow of aggregated, particulate matter, said method comprising the steps of:

firing a high pressure gas device adapted for sudden release of high pressure compressed gas in the vicinity of a vessel containing aggregated particulates, the firing being effected according to a set of preselected operating parameters, and the emitted shock waves and high-velocity gas flow separating the aggregated particulates causing them to flow through an outlet aperture of the vessel;

measuring a flow-related property of the flowing particulate aggregates;

providing the measured flow-related property of the flowing particulates to a control system, the control system correlating the flow-related property with a flow rate and calculating a set of updated operating parameters based on the correlated flow rate of the flowing particulates, the updated parameters to be used for further firings of the high pressure gas device, thereby to alter the flow rate of the separated particulates; and

displaying the updated operating parameters on a display so that they can be used to modify the operating parameters of the high pressure gas device for future firings thereof.

7. A method according to claim 6 further comprising a step of providing the updated operating parameters to the high pressure gas device by a user and having the user then fire the device.

8. A method according to any one of claims 6 further comprising a step of providing the updated operating parameters to the high pressure gas device via the control system which is in electronic communication with the high pressure gas device and then having the control system fire the device.

9. A method according to any one of claims 6 further comprising a step of selectably using either a user to provide the updated operating parameters to the high pressure gas device and having the user then fire the device or using the control system which is in electronic communication with the high pressure gas device to provide the updated operating parameters to the high pressure gas device and having the control system then fire the device.

10. A method according to any one of claims 6-9 wherein said operating parameters include the pressure of the compressed gas supplied to the high pressure gas device, the frequency of the firings in each predetermined firing cycle and the duration of the predetermined firing cycle.

1 1. A method according to any one of claims 6- 10 wherein said method further includes a step of establishing a correlation between the operating parameters of the high pressure gas device and the flow rate of the particulates.

12. A method for generating a controlled flow of aggregated particulate matter, said method comprising the steps of:

firing a high pressure gas device adapted for sudden release of high pressure compressed gas in the vicinity of a vessel, the firing being effected according to a set of preselected operating parameters, whereby the firing stimulates particulate flow in the vessel so that it egresses through an outlet aperture of the vessel;

monitoring the flow rate of the particulates in the vessel or at the outlet aperture of the vessel; and

13. A method according to claim 12 further including a step of displaying the updated operating parameters on a display so that they can be used to adjust the operating parameters of the device for future firings thereof.

14. A system for generating a controlled flow of aggregated particulate matter, said system comprising:

a high pressure gas device adapted for sudden release of high pressure compressed gas in the vicinity of a vessel according to a set of operating parameters, thereby to expose aggregated particulate matter within the vessel to separation forces causing separation of the particulates and facilitating flow thereof;

a measuring apparatus for monitoring the flow rate of the flowing separated particulates by measuring a flow-related property of the particulates;

a control system in operative communication with said high pressure gas device for controlling firing thereof and for generating shock waves therewith and also in operative communication with said measuring apparatus for monitoring the flow rate of the separated particulates, said control system operative to compute a set of updated operating parameters based on the measured flow rate and for use in the operation of said device; and

a display for displaying at least the updated operating parameters computed by said control system.

15. A system according to claim 14 further comprising an input device in operative communication with said high pressure gas device for generating shock waves whereby a user provides the updated operating parameters displayed on said display to said gas device via said input device thereby to adjust the rate of firing of said device and the flow rate resulting therefrom.

16. A system according to any one of claims 14 wherein the updated operating parameters calculated by said control system to adjust the rate of firing of said device are provided by said control system to said device, thereby to adjust the resulting flow rate to a preselected flow rate.

17. A system according to anyone of claims 14 wherein said system is a dual mode operating system including a user operated mode and a control system directed mode, wherein said system further comprises an input device for use in said user operated mode, said input device in operative communication with said high pressure gas device and whereby the user provides the updated parameters displayed on said display to said device for generating gas-borne shock waves, thereby to adjust the rate of firing of said device and the flow rate resulting therefrom, and in said control system directed mode said control system is in electronic communication with said high pressure gas device whereby the updated operating parameters computed by said control system are supplied to said high pressure gas device, thereby to adjust the rate of firing of said device and flow rate resulting therefrom.

18. A system according to any one of claims 14-17 wherein the set of operating parameters comprise the pressure of the compressed gas supplied to the device, the frequency of the firings in each firing cycle and the duration of the firing cycle.

19. A system according to any one of claims 14-18 wherein said display further displays the previous operating parameters and the flow rate resulting therefrom.

20. A system according to any one of claims 14-19 further including an enclosure member said member having an at least partially open end and wherein said high pressure gas device is positioned therein, said enclosure member adapted to be fastened to the vessel, generally in a region of an aperture in a wall of the vessel with said at least partially open end of said enclosure member essentially abutting the aperture of the vessel so that the shock waves generated by said high pressure gas device enter the vessel through the aperture after traveling within said enclosure member.

21. A system according to claim 20 further including at least one shock absorbing element in mechanical connection with said enclosure member and said high pressure gas device, said at least one shock absorbing element absorbing the shock of gas impulses generated by said device.

22. A system according to any one of claims 20 or 21 wherein said high pressure gas device further includes at least one discharge port, said discharge port angled in the general direction of the wall of the vessel so that the discharged gas travels in the general direction toward the wall of the vessel when it exits said at least one discharge port and so that energy losses are thereby reduced when the gas is emitted from said at least one discharge port so angled.

23. A system according to any one of claims 14-22 wherein said high pressure gas device is operative at a pressure range of about 10 to about 250 bars.

24. A system according to any one of claims 14-22 wherein said high pressure gas device is operative at a pressure range of about 50 to about 150 bars.