EP2274110B1

EP2274110B1 - Decontamination method and system for air intake plants, and cleaning head for said system

Info

Publication number: EP2274110B1
Application number: EP09721063A
Authority: EP
Inventors: Stefano Borean
Original assignee: Aria Srl
Current assignee: Aria Srl
Priority date: 2008-03-12
Filing date: 2009-03-09
Publication date: 2012-09-26
Anticipated expiration: 2029-03-09
Also published as: WO2009112446A1; ITUD20080052A1; EP2274110A1

Description

FIELD OF THE INVENTION

The present invention concerns a method and a system to decontaminate air intake plants in an optimized manner. In particular, the method and the system according to the present invention provide the combined use of an aspirator and a cleaning head for the dry removal of particulate inside the plant, without dispersing it in the environment.

BACKGROUND OF THE INVENTION

It is known that to carry out operations to decontaminate air intake plants, that is, the mechanical and confined removal of particulate present in the conduits of the plant without using chemical products, systems are used that are provided with an intake apparatus and a cleaning apparatus. Examples of devices of the state of the art are disclosestum US-A-3.658.589 , US-A-4.718.142 and FR-A1-2.830.470 .
It is known in the state of the art to generate, with the intake apparatus, a depression inside the whole conduit to be decontaminated and to introduce inside the conduit a wire-guided cleaning head that is part of the cleaning apparatus, and is able to advance in the conduit so as to clean it.
Among the most commonly used equipment for this type of cleaning a first system is known in which the cleaning head has a substantially tapered shape with head and tail ends of reduced sizes.
The head also defines, in its central zone where it is largest, a circular crown from which a first pressurized fluid is delivered, normally compressed air, in a direction opposite the direction of advance. The fluid delivered has the sole function of causing the propulsion of the head inside the conduit
At the head end of the cleaning head a nozzle is provided, able to deliver, in the same direction as the advance of the head, a second cleaning and sanitizing fluid, different and distinct from the first fluid, normally a nebulized liquid.
At the tail end of the cleaning head a flexible pipe is connected, internally conformed so as to feed separately both the first and the second fluid. The flexible pipe has a degree of flexibility such as to allow an operator to guide from outside the cleaning head inside the conduit to be decontaminated.
In this type of known heads, the propulsion and cleaning take place separately.
Furthermore, this type of known cleaning heads have a relatively heavy weight, especially due to the complex internal conformation of both the flexible pipe and also the body of the cleaning head itself, to provide different and separate feed and delivery pipes of the two fluids delivered, of which one is normally a liquid.
This weight limits the range of action of the cleaning head inside the conduit, which can reach at most 15 meters, instead of the potential 25-30 meters.
Moreover, the head nozzle not only has a weight that affects the overall weight of the cleaning head, but also is frequently subject to accidental knocks against the internal walls of the conduit to be cleaned.
Therefore, it is necessary to carry out frequent maintenance, and possibly to replace the nozzle or the entire cleaning head, and also operations to repair any conduits that have been dented.
A second system is also known, in which the cleaning head has a shape that substantially recalls a jellyfish. The head has a front part like a cap and a body tapering toward the tail end and provided with a plurality of mobile appendices, or tentacles, made of flexible material.
In this solution, the front part is made of or lined with elastomer material in order to absorb the knocks, and defines, in correspondence with the zone where it is joined to the tapered body, a circular crown to deliver a fluid under pressure to cause the propulsion.
The cleaning and mechanical removal of the particulate is carried out in this case only with the mobile appendices, which are made of plastic or elastomer material with a determinate degree of flexibility.
In this solution too, the propulsion and cleaning are performed separately, and the cleaning head has a relatively heavy weight, especially due to the composition of the front part, and due to the need to provide a body large enough to support a high number of appendices so as to guarantee an effective decontamination of the conduit.
In this known solution too, if on the one hand the front part made of elastomer allows to absorb the knocks, on the other hand it causes an increase in friction with the internal surfaces of the conduit.
For these reasons, but not only, this type of known system has a limited range of action of the cleaning head inside the conduit, and can reach at most 10-15 meters instead of the potential about 25-30 meters.
Furthermore, the cleaning action of the tentacles may be not very efficient and due to their wear and possible breakage the cleaning head may need to be completely replaced.
It must also be considered that, in both said known solutions, the intake apparatus must be strengthened on each occasion specifically, according to the volumes of the conduits to be decontaminated.
Purpose of the present invention is to achieve a system and perfect a method to decontaminate air intake plants which is simple, economical, safe, effective and which allows to solve the problems of the state of the art.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.
A decontamination system for air intake plants according to the present invention comprises at least a cleaning apparatus able to be at least partly inserted inside a conduit of the plant in order to remove any possible dirt present, for example by dry cleaning, in particular on the internal surfaces of the conduit, and an intake apparatus able to take in the dirt removed by the cleaning apparatus, in order to prevent the dispersion thereof into the environment.
In accordance with said purpose, the cleaning apparatus comprises at least a cleaning head able both to be inserted and moved inside the conduit, and also to deliver under pressure at least a stream of fluid.
According to a characteristic feature of the present invention, the cleaning head comprises a tapered hollow body conformed so as to define at least a first shaped exit aperture that directs at least a first portion of the stream of fluid in the direction opposite the direction of advance of the head, and with an angle such as to hit, advantageously uniformly, at least part of the internal surfaces of the conduit, so as to guarantee that the dirt is removed, and at the same time to actuate the movement of the cleaning head.
In this way, with a single fluid the invention guarantees both to remove the dirt, and hence to decontaminate the plant, and also to move the head inside the conduit of the plant.
, The cleaning head also comprises at least a second aperture, independent and separate from the first aperture, and shaped so as to direct a second portion of the stream of fluid in the direction opposite the direction of advance of the head, and with an angle such as to determine the movement of the cleaning head inside the conduit of the plant.
In this way, since both the first and the second portion of stream of fluid are directed in the opposite direction to the direction of advance, the propulsion of the cleaning head is optimized, so as to further increase the range of action of the head.
With the present invention it is therefore possible to use a single fluid, for example two-phase, which is delivered both from the first aperture and also from the second aperture. By two-phase fluid we mean a proportional mixture of two or more fluids, for example air and nebulized sanitizing liquid.
This advantage allows to simplify the internal conformation of the hollow body, reducing the overall weight of the cleaning head, and thus increasing its range of action inside the plant, even up to about 20 meters.
According to a variant, the fluid is fed under pressure through a flexible pipe connected to the tail end of the cleaning head.
With the solution according to the present invention, the flexible pipe is also simplified since it must provide for the flow of a single fluid and not two or more separate fluids.
We therefore have a further reduction in the overall weight of the cleaning head.
The hollow body comprises an annular slit which defines the exit of the first aperture, so that the stream of fluid exiting is substantially uniform.
The hollow body comprises two semi-shells coupled with each other and shaped so as to define the annular slit.
Furthermore, this conformation determines a dynamic depression of the stream that allows a substantially constant adhesion of the cleaning head to the internal surfaces of the conduit.
According to another variant, the intake apparatus is of the modular type and comprises one or more filtering modules, possible coupled with each other, and a ventilation member able to generate the intake depression in the conduit.
In this way, each filtering member can be individually replaced by a new one or another type, depending, on each occasion, on the type of decontamination and/or degree of saturation of each of them.
The ventilation member is advantageously disposed downstream of the filtering module or modules, so as to guarantee, even in the accidental event of a loss of seal, that the dirt collected is not dispersed into the environment.
According to another variant, the intake apparatus comprises one or more closing elements, able to be disposed transverse to the conduit so as to effect a volumetric division thereof. In this way, the decontamination operations are carried out in closed and limited segments of the conduit, optimizing functionality and consumption of the entire decontamination system.
According to a variant, the cleaning apparatus comprises at least a compression member able to generate the stream of fluid. Advantageously, between the compression member and the cleaning head a device is provided to purify the fluid.
In the case where a two-phase fluid is used, between the compression member and the cleaning head, a mixer member is advantageously provided able to mix the fluids proportionally.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of a preferential form of embodiment, given as a non-restrictive example with reference to the attached drawings wherein:

fig. 1 is a schematic view of a decontamination system according to the present invention;
fig. 2 is a schematic view of an enlarged detail of the system in fig. 1;
fig. 3 is a schematic view of a longitudinal section of the enlarged detail in fig. 2;
fig. 4 is a schematic view of an enlarged detail of the system in fig. 1;
fig. 5 is a schematic view of a variant of the system in fig. 1.

DETAILED DESCRIPTION OF A PREFERENTIAL FORM OF EMBODIMENT

With reference to figs. 1, 2 and 3, a decontamination system 10 according to the present invention is shown schematically, applied for the dry decontamination and sanitization of a conduit 11 of an air intake plant.
In particular, the decontamination system 10 comprises a cleaning apparatus 12 which by means of a pressurized fluid effects the removal of dirt from the conduit 11, and an intake apparatus 13 that takes in from inside the conduit 11 the dirt removed by the cleaning apparatus 12.
In this case, the cleaning apparatus 12 comprises a compressor 15, a purification device 16, a mixer 17, a flexible pipe 19 and a cleaning head 20.
The compressor 15 is disposed outside the conduit 11 to be decontaminated, is connected pneumatically to the cleaning head 20, and is able to generate a stream of fluid with a desired pressure. In this case, the fluid used is compressed air and has a pressure comprised between about 5 bar and about 10 bar, advantageously about 7 bar.
Downstream of the compressor 15, and always outside the conduit 11, a purification device 16 is provided, which allows to reduce to a minimum the presence of pollutants from the stream of compressed air generated by the compressor 15.
In association with the purification device 16 a mixer 17 is provided, such as for example a pneumatic pump, able to mix proportionally a nebulized sanitizing liquid with the compressed air, so as to form a desired single two-phase fluid.
The mixer 17 is connected to the cleaning head 20 by means of the flexible pipe 19, which has at least a segment outside and a segment inside the conduit 11. The flexible pipe 19 is conformed simply with a tubular shape, to allow the single two-phase fluid provided to flow therein.
The flexible pipe 19 is made for example of rubber, plastic or other material able on the one hand to guarantee a good pneumatic seal and resistance to wear and knocks and, on the other hand, a weight and degree of flexibility such as to be able to follow the path, also tortuous, of the conduit 11 to be decontaminated.
The degree of flexibility of the flexible pipe 19 is such as to allow an operator, located outside the conduit 11, to move the cleaning head 20 with respect to the section of the conduit 11, simply by acting on the flexible pipe 19.
The cleaning head 20 is made of light metal material, for example aluminum or its alloys, and comprises a tapered hollow body 25 defined substantially by two semi-shells, respectively a first 26 and a second 27, coupled with each other in a central zone of the cleaning head 20.
The conformation of the hollow body 25 is such as to guarantee an optimum balance of the cleaning head 20 during its advance inside the conduit 11.
The first semi-shell 26 is disposed in the head part of the hollow body 25 and has a substantially conical or truncated cone shape, to facilitate the movement and insertion of the cleaning head 20 inside the conduit 11.
According to a variant, the first semi-shell 26 comprises externally at least a portion covered with an elastomer material which absorbs and deadens the accidental knocks against the internal part of the conduit to be decontaminated.
The first semi-shell 26 also comprises a collar 29 made in correspondence with its rear end, that is, the end near the central zone of the cleaning head 20 and coupling with the second semi-shell 27. The collar 29, unlike the remaining conical or truncated cone part of the first semi-shell 26, has circular surfaces substantially parallel to a longitudinal axis of the cleaning head 20.
The second semi-shell 27 is disposed in the tail part of the hollow body 25, it also has a substantially conical or truncated cone shape, and defines at one end a tubular terminal 30 on which the end of the flexible pipe 19 is coaxially mounted, to allow the entry of the two-phase fluid inside the hollow body 25.
According to a variant, at least one or both of the semi-shells 26 and 27, instead of having a conical or truncated cone shape, have a rounded external shape so as to define a hollow body with a substantially spherical, ellipsoidal or ovoid shape.
The second semi-shell 27 comprises a collar 31 made in correspondence with its front end, that is, the end near the central zone of the cleaning head 20 and coupling with the first semi-shell 26. The collar 31, unlike the remaining conical or truncated cone part of the second semi-shell 27, has circular surfaces substantially parallel to a longitudinal axis of the cleaning head 20.
In the assembled condition of the two semi-shells 26 and 27, the respective collars 29 and 31 overlap parallel one another, and between them define an annular slit 32, open toward the tail part of the cleaning head 20, and from which the stream of two-phase fluid is able to exit uniformly.
Therefore, the head 20 thus conformed delivers a stream of fluid uniformly against the walls of the conduit 11, and efficiently removes the dirt present.
The reciprocal conformation of the two collars 29 and 31 is such as to define an annular slit 32 able to direct at exit the two-phase fluid so as to determine a correct impact against the internal walls of the conduit 11, and also to generate the propulsion of the cleaning head 20 along the conduit 11, and also to define a dynamic pressure at exit, able to allow to maintain a condition of movement of the cleaning head 20 adhering to the walls of the conduit 11 to be cleaned.
The second semi-shell 27 comprises one or more through holes 33 on its conical or truncated cone part, in this case three disposed at 120° with respect to each other, and able to define a second outlet for the fluid. The through holes 33 are conformed so as to direct the stream of two-phase fluid in a direction substantially opposite the direction of advance of the cleaning head 20, so as to improve the conditions of advance thereof.
The second semi-shell 27 comprises internally a chamber 35 to distribute the two-phase fluid, in which a conical or truncated cone deflector 36 is provided, coordinated with the shape of the second semi-shell 27. The deflector 36 is able to divide the pressurized stream arriving from the flexible pipe 19 in order to direct it uniformly inside the different zones of the hollow body 25.
In this way, the stream of two-phase fluid is divided in a desired manner, so as to guarantee its exit under pressure both through the annular slit 32 and also through the through holes 33.
In particular, inside the second semi-shell 27 a dividing wall 38 is provided, on which a plurality of passage holes 37 are made, of which only two are visible in the section in fig. 3, angularly offset with respect to each other and able to allow the passage of the fluid between one and the other of the two semi-shells 26, 27. The fluid that passes through the passage holes 37 is intended to exit under pressure from the annular slit 32.
The first and the second semi-shell 26, 27 are maintained reciprocally coupled by means of an attachment screw 34, inserted axially from the front top of the first semi-shell 26 and screwed into a relative threaded hole made at the rear of the deflector 36 of the second semi-shell 27.
The intake apparatus 13 comprises an intake pipe 21, a modular aspirator 22 and a plurality of closing walls 23.
The intake pipe 21 is on one side generally connected inside the conduit 11 to be decontaminated and on the other side connected to the modular aspirator 22, so as to determine a desired depression or intake inside the conduit 11.
The modular aspirator 22 is provided outside the conduit 11 and comprises a plurality of filtering modules disposed in a battery upstream of a ventilation member 39, which generates the intake stream of air.
In particular, each of the filtering modules has its own coefficient of air filtration.
In this case, a first filtering module 40 with low efficiency is provided, such as a plenum chamber; a second filtering module 41 with a degree of efficiency comprised between about 20% and about 40%, such as an average filtering medium; a third filtering module 42 with a degree of efficiency comprised between about 70% and 90%, and a fourth filtering module 43 with a degree of efficiency comprised between about 80% and 99%.
In particular, the first filtering module 40 comprises at the lower part a compartment 45 to discharge the solid deposits.
Furthermore, a relative pressure switch 46 is associated with each of the filtering modules indicated by the reference numbers 41, 42 and 43.
Each pressure switch 46 is able to verify and indicate the actual loss of load of the filtering modules 41, 42 and 43, so as to indicate to the operator any need to replace one or another of said modules.
The modular composition of the aspirator 22 allows to reduce, implement, replace or change, selectively, the individual filtering modules 40, 41, 42 and 43 according to the specific operations or operating conditions.
There are two or more closing walls 23 and they are conformed so as to close the conduit 11 transversely, so that the modular aspirator 22 generates a determinate depression in a limited zone of the conduit 11.
The cleaning head 20 is disposed inside the limited zone and decontamination is performed.
This solution allows to optimize the air intake conditions inside the conduit 11 and thus guarantee the correct intake and discharge of the dirt that is removed by the cleaning head 20.
According to a variant, the closing walls 23 each comprise a shutter.
According to another variant, the closing walls 23 comprise fire-barrier plates.
The decontamination system 10 as described heretofore functions as follows.
First of all, the conduit 11 to be decontaminated is prepared, possibly by removing the air distribution accessories, and by positioning the closing walls 23 appropriately, so as to define the closed sector in which decontamination is to be performed.
Once the closed sector has been defined, the intake pipe 21 is connected and the modular aspirator 22 is activated, to generate the determinate depression.
Then the cleaning head 20 is inserted inside the closed sector of the conduit 11.
Advantageously, both the intake pipe 21 and the cleaning head 20 are put into cooperation with the inside of the conduit 11 through respective apertures already present in the conduit 11 and normally used to distribute air.
According to a first form of embodiment (fig. 1), the intake pipe 21 and the cleaning head 20 are put into cooperation with the conduit through two independent apertures.
In a second form of embodiment (fig. 5), the intake pipe 21 is put into cooperation with the conduit through a relative aperture, whereas the cleaning head 20 is inserted into the intake pipe 21 and enters into the conduit 11 through the same aperture as the intake pipe 21.
In any case, once the cleaning head 20 has been introduced inside the conduit 11, the compressor 15 is activated so as to generate the stream of compressed air.
In a first step of the decontamination, the mixer 17 remains inactive, so that the removal of the dirt inside the conduit 11 occurs only with the compressed air.
As we said, thanks to the conformation of the direction of the annular slit 32 and the through holes 33, the cleaning head 20 removes the dirt uniformly and advances inside the conduit 11.
The depression generated by the modular aspirator 22 causes the dirt removed to be taken in through the intake pipe 12.
In a second step of decontamination, the mixer 17 is activated, so that the cleaning head 20 delivers a two-phase fluid including sanitizing fluid.
Once this step is terminated, the mixer 17 is again de-activated to deliver only compressed air and to dry the inside of the decontaminated conduit 11.
At the end of these operations, the compressor 15 and the ventilation member 39 are switched off, the cleaning head 20 is removed, the intake pipe 21 is disconnected and the closing walls 23 removed.
The above decontamination operations are repeated for another segment of the conduit 11 and so on.
In parallel with the decontamination operations of the conduit 11, the air distribution accessories are decontaminated, both removed from the conduit 11 and also present on the conduit and also any other parts of the plant.
These operations are carried out "on the ground" or directly on the plant, using chemical products or mechanical techniques to remove the dirt in a substantially traditional manner.

Claims

Decontamination system for air intake plants comprising at least a cleaning apparatus (12) able to be at least partly inserted inside a conduit (11) of said plant so as to remove any dirt possibly present, in particular on at least part of the internal surfaces of said conduit (11), and a suction apparatus (13) able to take in the dirt removed by said cleaning apparatus (12), to prevent it from being dispersed into the environment, said cleaning apparatus (12) comprising at least a cleaning head (20) able to be inserted and moved inside the conduit (11), and also to deliver under pressure at least a stream of fluid, in which said cleaning head (20) comprises a hollow body (25) conformed so as to define at least a first exit aperture (32) shaped so as to direct at least a first portion of the stream of fluid in a direction such as to guarantee the propulsion forward of said cleaning head (20), and with an angle such as to hit said internal surfaces, characterized in that said hollow body (25) has a tapered shape and substantially comprises a first semi-shell (26) and a second semi-shell (27), coupled with each other in a central zone of the cleaning head (20), said first semi-shell (26) defining a head part of the hollow body (25) and said second semi-shell (27) defining a tail part of the hollow body (25), both said first semi-shell (26) and said second semi-shell (27) having a substantially conical or truncated cone shape, opposite each other, said first semi-shell (26) comprising a collar (29) having circular surfaces substantially parallel to a longitudinal axis of the cleaning head (20), and said second semi-shell (27) comprising a collar (31) made in correspondence with a zone where it couples with the first semi-shell (26), said collar (31) cooperating with said collar (29) of the first semi-shell (26) in order to form an annular circular slit (32) open toward the tail part of the cleaning head (20) and defining said first aperture (32) for the stream of fluid to exit uniformly, and wherein said second semi-shell (27) comprises on its conical or truncated cone part one or more through holes (33) conformed so as to direct the stream of the fluid opposite the direction of advance of said cleaning head (20), to improve the conditions of advance thereof.
System as in claim 1 , characterized in that the second semi-shell (27) comprises internally at least a distribution chamber (35) to distribute the fluid, in which at least a deflector (36) is provided, able to divide the pressurized flow in order to direct it uniformly toward the first aperture (32) and the second aperture (33).
System as in any claim hereinbefore, characterized in that the second semi-shell (27) comprises a tubular terminal (30) on which a flexible pipe (19) is coaxially mounted, able to feed the stream of fluid under pressure inside the hollow body (25).
System as in any claim hereinbefore, characterized in that the intake apparatus (13) is modular and comprises one or more filtering modules (40, 41, 42, 3), and a ventilation member (39) connected downstream of the filtering modules and able to generate a determinate intake depression in the plant.
System as in any claim hereinbefore, characterized in that the cleaning apparatus (12) comprises at least a compression member (15) able to generate the stream of fluid, a purification device (16) to purify the fluid and a flexible pipe (19) able to connect the compression member (15) to the cleaning head (20).
System as in any claim hereinbefore, characterized in that said fluid is compressed air.
Cleaning head for a decontamination system for air intake plants, able both to be inserted and moved inside a conduit (11) of said plant, and also to deliver under pressure at least a stream of fluid, in particular on at least part of the internal surfaces of said conduit (11), to remove the possible dirt present, in which it comprises a hollow body (25) conformed so as to define at least a first exit aperture (32) advantageously annular and shaped so as to direct at least a first portion of the stream of fluid in a direction such as to guarantee its propulsion forward, and with an angle such as to hit said internal surfaces, wherein said hollow body (25) has a tapered shape and substantially comprises a first semi-shell (26) and a second semi-shell (27), coupled with each other in a central zone of the hollow body (25), said first semi-shell (26) defining a head part of the hollow body (25) and said second semi-shell (27) defining a tail part of the hollow body (25), both said first semi-shell (26) and said second semi-shell (27) having a substantially conical or truncated cone shape, opposite each other, said first semi-shell (26) comprising a collar (29) having circular surfaces substantially parallel to a longitudinal axis of the cleaning head (20), and said second semi-shell (27) comprising a collar (31) made in correspondence with a zone where it couples with the first semi-shell (26), said collar (31) cooperating with said collar (29) of the first semi-shell (26) in order to form an annular slit (32) open toward the tail part of the cleaning head (20) and defining said first aperture (32) for the stream of fluid to exit uniformly, and [characterized in that] said second semi-shell (27) comprises on its conical or truncated cone part one or more through holes (33) conformed so as to direct the stream of the fluid opposite the direction of advance of said cleaning head (20), to improve the conditions of advance thereof.
Decontamination method for air intake plants, using a system as in claim 1, said method comprising at least a first step of inserting and moving a cleaning head (20) of the cleaning apparatus (12) inside said conduit (11), in order to deliver under pressure at least a stream of fluid, characterized in that in said first step said cleaning head (20) directs, by means of a first aperture (32), at least a first portion of the stream of fluid in a direction such as to guarantee its propulsion forward, and with an angle such as to hit said internal surfaces uniformly.
Method as in claim 8, characterized in that in said first step the cleaning head (20) also directs, by means of a second aperture (33) independent and separate from the first aperture (32), a second portion of the stream of fluid in the same direction as the exit direction of the first portion of fluid, in order to contribute to its forward propulsion inside said conduit (11).
Method as in any claim 8 or 9, characterized in that said fluid used is compressed air.