Title of Invention	A SYSTEM FOR SUPPRESSING CARBON DIOXIDE FROM CONTROLLED ATMOSPHERE ENVIRONMENTS
Abstract	A system for suppressing carbon dioxide from controlled atmosphere environments, comprising at least one activated-carbon filter, which is connected to an intake duct and a discharge duct, which are adapted to introduce and extract air into and from a storage room; at least one blower is provided along the discharge duct and has, upstream or downstream of the activated-carbon filter, in succession, a discharge duct which can be controlled by a check valve, and a first valve, the blower being associated with a reversal valve, which is adapted to switch the flow during the regeneration step so as to perform the regeneration of the activated-carbon filter or filters in countercurrent.

Title of Invention

A SYSTEM FOR SUPPRESSING CARBON DIOXIDE FROM CONTROLLED ATMOSPHERE ENVIRONMENTS

Abstract

A system for suppressing carbon dioxide from controlled atmosphere environments, comprising at least one activated-carbon filter, which is connected to an intake duct and a discharge duct, which are adapted to introduce and extract air into and from a storage room; at least one blower is provided along the discharge duct and has, upstream or downstream of the activated-carbon filter, in succession, a discharge duct which can be controlled by a check valve, and a first valve, the blower being associated with a reversal valve, which is adapted to switch the flow during the regeneration step so as to perform the regeneration of the activated-carbon filter or filters in countercurrent.

Full Text	WO 2006/097217 PCT/EP2006/002034 SYSTEM FOR SUPPRESSING CARBON DIOXIDE FROM CONTROLLED ATMOSPHERE ENVIRONMENTS Technical Field The present invention relates to a system for suppressing carbon dioxide from controlled atmosphere environments. Background Art Conventionally, the reduction of carbon dioxide (CO2) in storage rooms for preserving fruit with a low CO2 and oxygen content is performed in various manners, including the following: - introduction in the storage rooms of chemical substances, such as calcium hydrate, capable of reacting with CO2 to obtain solid compounds; - use of machines which draw the CO2-rich air in order to bring it into contact with particular chemical substances, such as aqueous solutions of potassium hydrate or of particular amines, which react with the CO2 that is present in the air, the purified air being then returned to the storage room; - introduction of nitrogen in the storage room, consequently reducing the CO2 that is present by air exchange; - use of activated-carbon absorbers, modified so as to have an injection of nitrogen in the filters, which allows to reduce the amount of oxygen-rich air which normal activated-carbon absorbers introduce in the storage rooms after each step for regenerating the filters with external air. The first two methods require very intensive work, considerable workforce and entail considerable costs for the disposal of the spent chemical substances. The third method entails very high operating costs, due to the cost of supplying nitrogen, while the fourth method is by far the most valid but requires the availability of additional devices for generating and storing the WO 2006/097217 PCT/EP2006/002034 2 nitrogen and accordingly requires heavy plant investments and operating costs. In order to try to solve the drawbacks noted above, systems have been proposed which have one or more activated-carbon filters and one or more filters for absorbing oxygen using molecular or chemical type sieves, which are designed to absorb either the oxygen from the air before it is introduced in the storage room or the oxygen that is present in the activated-carbon filters before the passage of the air to be filtered. These systems, moreover, are disclosed in Italian patent no. 1,297,501 by Villa Ivano and Mercadini Massimo. However, presently the need is particularly felt to preserve food, particularly fruit, in environments which have an extremely low oxygen content but also a low CO2 content. Disclosure of the Invention The aim of the present invention is to provide a system for suppressing carbon dioxide from controlled atmosphere environments, particularly from storage rooms for preserving food products such as fruit, which is capable of eliminating or in any case reducing drastically the drawbacks noted in the systems currently in use. This aim and this and other objects, which will become better apparent hereinafter, are achieved by a system for suppressing carbon dioxide from controlled atmosphere environments, comprising at least one activated-carbon filter, which is connected to an intake duct and a discharge duct, adapted to introduce and extract air into and from a storage room, at least one blower being provided along said discharge duct, said blower having, upstream or downstream of said at least one activated-carbon filter, in succession, a discharge duct which Can be controlled by a check valve, and a first valve, characterized in that said blower is associated with a reversal valve, which is adapted to; switch the flow during the regeneration step so as to perform the regeneration of said at least one activated-carbon WO 2006/097217 PCT/EP2006/002034 3 filter in countercurrent. Brief Description of the Drawings Further characteristics and advantages of the invention will become better apparent from the description of some preferred but not exclusive embodiments of a system for suppressing carbon dioxide from controlled atmosphere environments according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein: Figure 1 is a schematic view of a system with an activated-carbon filter and with discontinuous purification according to the present invention; Figure 2 is a diagram of a system with two activated-carbon filters with continuous purification during the step for absorption by the activated- carbon filter A and regeneration of the activated-carbon filter B; Figure 3 is a diagram of a system with two activated-carbon filters with continuous treatment in the first switching step; Figure 4 is a diagram of a system with two activated-carbon filters with continuous purification during the step for absorption by the activated- carbon filter B and regeneration of the activated-carbon filter A; Figure 5 is a diagram of a system with two activated-carbon filters with continuous purification during the second switching step. Ways of carrying out the Invention In the examples of embodiments that follow, individual characteristics, given in relation to specific examples, may actually be interchanged with other different characteristics that exist in other examples of embodiments. Moreover, it is noted that anything found to be already known during the patenting process is understood not to be claimed and to be the subject of a disclaimer. Initially with reference to the diagram of Figure 1, the reference numeral 1 generally designates a system according to the invention, which has at least one controlled-atmosphere storage room C, typically a fruit WO 2006/097217 PCT/EP2006/002034 4 preservation room, an intake duct 2 and a discharge duct 3 for the air to be introduced into, and removed from, the storage room C. The system 1 has at least one activated-carbon filter B, which is connected to the storage room C by means of the intake duct 2 and the discharge duct 3. In particular, the activated-carbon filter B is capable of trapping the CO2 contained in the fluid medium which flows through it and is connected in parallel to the intake duct 2 and to the discharge duct 3. A first valve 4 is provided on the discharge duct 3 and a blower 5 is arranged downstream of said first valve; a first discharge duct 6 is connected between the first valve 4 and the blower 5 and is controlled by a first valve 7. The activated-carbon filter B is connected to a second discharge duct 8, which is controlled by a first valve 9, while a second valve 10 is provided along the intake duct 2. According to the present invention, the blower 5 is associated with a reversal valve 11, which is adapted to exchange the stream during the regeneration step, so as to regenerate the activated-carbon filter B in countercurrent. Advantageously, the blower 5 is functionally connected to an inverter 12, which is associated with a control device (not shown in the figures) and is adapted to increase the speed of the blower 5 (and therefore the flow-rate of the fluid medium through the discharge duct 3) during the step for regeneration of the activated-carbon filter B. The valves 4, 7, 9 and 10 must be gas-tight, and despite being shown as single valves can of course be grouped in a three-way arrangement Therefore, the system 1 described above has a single activated-carbon filter B with discontinuous purification and operates according to four steps. During the first step, or CO2 absorption step, the valves 4 and 10 are open and the reversal valve 11 is in the normal position. The blower 5 draws WO 2006/097217 PCT/EP2006/002034 5 air from the storage room C, sends it to the activated-carbon filter B and returns purified air to the storage room c. Typically, the duration of this first step is approximately 5-10 minutes. If an inverter 12 is used, during this step a reduced speed of the blower 5 is used at the beginning of the step, increasing it a few seconds before said step ends. In the second step, or exchange step, the valves 7 and 10 are open and the reversal valve 11 is still in the normal position; the blower 5 draws external air and sends it to the activated-carbon filter B; said air, depleted of its oxygen, is introduced in the storage room C. The duration of this second step is on the order of 10-20 seconds. The third step, or regeneration step, is performed with the valves 7 and 9 open and with the reversal valve 11 in the switching position. The blower 5 draws external air from the valve 9, conveys it through the activated-carbon filter B, and returns it outside. The duration of this step is similar to the duration of the first step if the inverter 12 is present. Otherwise, i.e., if the speed of the blower 5 is constant, it is convenient to provide a duration which is slightly longer by approximately 10-20%. In the fourth step, or decompensation step, the valves 4 and 9 are open and the reversal valve 11 is in the normal position. The blower 5 draws air from the storage room C by means of the valve 4 and sends it to the activated-carbon filter B, and the air that passes through the activated- carbon filter B is then expelled externally. The duration of this step is approximately 10-20 seconds, depending on the flow-rate of the blower 5. The cycle then resumes from the first step. The diagrams shown in Figures 2 to 5 illustrate a system 1 with a dual activated-carbon filter (A and B), which is therefore capable of performing continuous purification of the air before it is introduced in the storage room C. The components are substantially the same ones shown in Figure 1, but they are duplicated; the reference letter A designates the components WO 2006/097217 PCT/EP2006/002034 6 related to the activated-carbon filter A and the letter B designates those related to the other activated-carbon filter B. In this case also, the blower 5 is associated with a reversal valve 11, which is adapted to switch the flow during the regeneration step, so as to regenerate the activated-carbon filters A and B in countercurrent. Advantageously, the blower 5 is connected functionally to an inverter 12, which is associated with a control device (not shown in the figures) and is adapted to increase the speed of the blower 5 (and therefore the flow-rate of the fluid medium through the discharge duct 3) during the step for regeneration of the activated-carbon filters A and B. An additional fan 6b is also provided. The system operates completely automatically and the steps are controlled by a PLC device. The operating cycle is performed in six steps, during which the fans 5 and 6b run constantly. The first step (shown schematically in Figure 2) provides absorption by the activated-carbon filter A and regeneration of the activated-carbon carbon filter B. The valves 4a, 4d, 9a and 9b are open and the reversal valve 11 is in the normal position. The additional fan 6b draws air from the storage room C and sends it to the first activated-carbon filter A, and at the same time returns purified air into the storage room C. The blower 5, optionally driven by the inverter 12 at a high frequency (for example 62 Hz, a flow-rate which is approximately 20% higher than a normal frequency of 50 Hz) draws air from the outside and conveys it through the second activated-carbon filter B for a period ranging from 5 to 10 minutes. In the second step, or pre-switching step, the condition of the valves remains unchanged, while the inverter brings the frequency of the speed variator to the normal speed (50 Hz) for approximately 8-10 seconds. In the third step, or first switching step (shown in Figure 3), the valves 4b, 4c, 9a and 9b are open and the reversal valve 11 is in the WO 2006/097217 PCT/EP2006/002034 7 switching position. The additional fan 6b draws air from the storage room C and sends it to the second activated-carbon filter B, and the air contained in said second activated-carbon filter B is expelled outside. The blower 5 draws air from the outside and sends it to the first activated-carbon filter A. The oxygen-poor air contained in the first activated-carbon filter A is returned to the storage room C. The duration of this step can range from 10 to 20 seconds depending on the flow-rate of the additional fan 6b and of the blower 5. The fourth step (shown schematically in Figure 4) provides absorption by the activated-carbon filter B and regeneration of the activated-carbon filter A. The valves 4c, 4b, 10a and 10b are open and the reversal valve 11 is in the normal position. The additional fan 6b draws air from the storage room C and conveys it toward the second activated-carbon filter B, and at the same time returns purified air into the storage room C. The blower 5, optionally controlled by the inverter 12 at a high frequency (for example 62 Hz, a flow-rate which is approximately 20% higher than a normal frequency of 50 Hz) draws air, conveying it toward the first activated-carbon filter A for a period ranging 5 from to 10 minutes. In the fifth step, or pre-switching step, the condition of the valves remains unchanged, while the inverter brings the frequency of the speed variator to the normal value (50 Hz) for approximately 8-10 seconds. In the sixth step, or second switching step (shown in Figure 5), the valves 4a, 4d, 10a and 10b are open and the reversal valve 11 is in the switching position. The additional fan 6b draws air from the storage room C and sends it to the second activated-carbon filter B, and the air contained in said second activated-carbon filter B is expelled externally. The blower 5 draws air from the outside and sends it to the first activated-carbon filter A. The oxygen-poor air contained in the first activated-carbon filter A is returned to the storage room C. This step can last from 10 to 20 seconds, depending on the flow-rate of the additional fan 6b and of the blower 5. WO 2006/097217 PCT/EP2006/002034 8 The cycle then resumes from the first step. The second and fifth steps are not indispensable for the operation of the system 1. The valves 4a, 4b, 4c, 4d and 9a, 9b, 9c and 9d can be grouped into four three-way valves or into two four-way valves. It has been found that a system according to the invention allows to improve the efficiency of activated-carbon filters without the aid of expensive injections of nitrogen or of oxygen absorbers. By improving efficiency while keeping the other conditions equal, the introduced oxygen is reduced.. All the characteristics of the invention indicated above as advantageous, convenient or the like, might also be omitted or be replaced with equivalents. The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Thus, for example, all the valves that are used can be of the electrical and/or pneumatic type and can be controlled by a control unit according to preset programs. Moreover, with reference to the embodiment with two activated- carbon filters, nothing prevents reversing, in the system, the positions of the blower 5 and of the additional fan 6b. Moreover, the system might be provided with an oxygen absorption filter which is designed to absorb either the oxygen of the air before it is introduced in the controlled atmosphere environment/environments or the oxygen that is present in the, or each, activated-carbon filter before the passage of the air to be filtered. In practice, the materials used, as well as the dimensions, may be any according to requirements. All the details may further be replaced with other technically WO 2006/097217 PCT/EP2006/002034 equivalent elements. The disclosures in Italian Patent Application No. VR2005A000034 from which this application claims priority are incorporated herein by reference. WO 2006/097217 PCT/EP2006/002034 10 CLAIMS 1. A system for suppressing carbon dioxide from controlled atmosphere environments, comprising at least one activated-carbon filter, which is connected to an intake duct and a discharge duct, said intake duct and said discharge duct being adapted to introduce and extract air into and from a storage room, at least one blower being provided along said discharge duct, said blower having, upstream or downstream of said at least one activated-carbon filter, in succession, a discharge duct which can be controlled by a check valve, and a first valve, characterized in that said blower is associated with a reversal valve, which is adapted to switch the flow during the regeneration step so as to perform the regeneration of said at least one activated-carbon filter in countercurrent. 2. The system for suppressing carbon dioxide according to claim 1, characterized in that said at least one blower is functionally connected to an inverter which is associated with a control device and is adapted to increase the speed of said blower during said step for regeneration of said least one activated-carbon filter. 3. The system for suppressing carbon dioxide according to one or more of the preceding claims, characterized in that it comprises two activated-carbon filters in parallel for continuous operation. 4. The system for suppressing carbon dioxide according to one or more of the preceding claims, characterized in that it comprises at least one filter for absorbing oxygen, which is designed to absorb either the oxygen of the air before it is introduced in the controlled-atmosphere environment or environments, or the oxygen that is present in the, or each, activated-carbon filter before the passage of the air to be filtered. 5. The system for suppressing carbon dioxide according to one or more of the preceding claims, characterized in that it comprises an additional fan which is adapted to draw air from said storage room. 6. The system for suppressing carbon dioxide according to one or WO 2006/097217 PCT/EP2006/002034 11 more of the preceding claims, characterized in that it comprises a respective reservoir which is associated with each activated-carbon filter. A system for suppressing carbon dioxide from controlled atmosphere environments, comprising at least one activated-carbon filter, which is connected to an intake duct and a discharge duct, which are adapted to introduce and extract air into and from a storage room; at least one blower is provided along the discharge duct and has upstream or downstream of the activated-carbon filter, in succession, a discharge duct which can be controlled by a check valve, and a first valve, the blower being associated with a reversal valve, which is adapted to switch the flow during the regeneration step so as to perform the regeneration of the activated-carbon filter or filters in countercurrent.

Full Text

WO 2006/097217 PCT/EP2006/002034
SYSTEM FOR SUPPRESSING CARBON DIOXIDE FROM
CONTROLLED ATMOSPHERE ENVIRONMENTS
Technical Field
The present invention relates to a system for suppressing carbon
dioxide from controlled atmosphere environments.
Background Art
Conventionally, the reduction of carbon dioxide (CO2) in storage
rooms for preserving fruit with a low CO2 and oxygen content is performed
in various manners, including the following:
- introduction in the storage rooms of chemical substances, such as
calcium hydrate, capable of reacting with CO2 to obtain solid
compounds;
- use of machines which draw the CO2-rich air in order to bring it
into contact with particular chemical substances, such as aqueous
solutions of potassium hydrate or of particular amines, which react
with the CO2 that is present in the air, the purified air being then
returned to the storage room;
- introduction of nitrogen in the storage room, consequently reducing
the CO2 that is present by air exchange;
- use of activated-carbon absorbers, modified so as to have an
injection of nitrogen in the filters, which allows to reduce the
amount of oxygen-rich air which normal activated-carbon absorbers
introduce in the storage rooms after each step for regenerating the
filters with external air.
The first two methods require very intensive work, considerable
workforce and entail considerable costs for the disposal of the spent
chemical substances.
The third method entails very high operating costs, due to the cost of
supplying nitrogen, while the fourth method is by far the most valid but
requires the availability of additional devices for generating and storing the

WO 2006/097217 PCT/EP2006/002034
2
nitrogen and accordingly requires heavy plant investments and operating
costs.
In order to try to solve the drawbacks noted above, systems have been
proposed which have one or more activated-carbon filters and one or more
filters for absorbing oxygen using molecular or chemical type sieves, which
are designed to absorb either the oxygen from the air before it is introduced
in the storage room or the oxygen that is present in the activated-carbon
filters before the passage of the air to be filtered. These systems, moreover,
are disclosed in Italian patent no. 1,297,501 by Villa Ivano and Mercadini
Massimo.
However, presently the need is particularly felt to preserve food,
particularly fruit, in environments which have an extremely low oxygen
content but also a low CO2 content.
Disclosure of the Invention
The aim of the present invention is to provide a system for
suppressing carbon dioxide from controlled atmosphere environments,
particularly from storage rooms for preserving food products such as fruit,
which is capable of eliminating or in any case reducing drastically the
drawbacks noted in the systems currently in use.
This aim and this and other objects, which will become better
apparent hereinafter, are achieved by a system for suppressing carbon
dioxide from controlled atmosphere environments, comprising at least one
activated-carbon filter, which is connected to an intake duct and a discharge
duct, adapted to introduce and extract air into and from a storage room, at
least one blower being provided along said discharge duct, said blower
having, upstream or downstream of said at least one activated-carbon filter,
in succession, a discharge duct which Can be controlled by a check valve,
and a first valve, characterized in that said blower is associated with a
reversal valve, which is adapted to; switch the flow during the regeneration
step so as to perform the regeneration of said at least one activated-carbon

WO 2006/097217 PCT/EP2006/002034
3
filter in countercurrent.
Brief Description of the Drawings
Further characteristics and advantages of the invention will become
better apparent from the description of some preferred but not exclusive
embodiments of a system for suppressing carbon dioxide from controlled
atmosphere environments according to the invention, illustrated by way of
non-limiting example in the accompanying drawings, wherein:
Figure 1 is a schematic view of a system with an activated-carbon
filter and with discontinuous purification according to the present invention;
Figure 2 is a diagram of a system with two activated-carbon filters
with continuous purification during the step for absorption by the activated-
carbon filter A and regeneration of the activated-carbon filter B;
Figure 3 is a diagram of a system with two activated-carbon filters
with continuous treatment in the first switching step;
Figure 4 is a diagram of a system with two activated-carbon filters
with continuous purification during the step for absorption by the activated-
carbon filter B and regeneration of the activated-carbon filter A;
Figure 5 is a diagram of a system with two activated-carbon filters
with continuous purification during the second switching step.
Ways of carrying out the Invention
In the examples of embodiments that follow, individual
characteristics, given in relation to specific examples, may actually be
interchanged with other different characteristics that exist in other examples
of embodiments.
Moreover, it is noted that anything found to be already known during
the patenting process is understood not to be claimed and to be the subject
of a disclaimer.
Initially with reference to the diagram of Figure 1, the reference
numeral 1 generally designates a system according to the invention, which
has at least one controlled-atmosphere storage room C, typically a fruit

WO 2006/097217 PCT/EP2006/002034
4
preservation room, an intake duct 2 and a discharge duct 3 for the air to be
introduced into, and removed from, the storage room C.
The system 1 has at least one activated-carbon filter B, which is
connected to the storage room C by means of the intake duct 2 and the
discharge duct 3.
In particular, the activated-carbon filter B is capable of trapping the
CO2 contained in the fluid medium which flows through it and is connected
in parallel to the intake duct 2 and to the discharge duct 3.
A first valve 4 is provided on the discharge duct 3 and a blower 5 is
arranged downstream of said first valve; a first discharge duct 6 is
connected between the first valve 4 and the blower 5 and is controlled by a
first valve 7.
The activated-carbon filter B is connected to a second discharge duct
8, which is controlled by a first valve 9, while a second valve 10 is provided
along the intake duct 2.
According to the present invention, the blower 5 is associated with a
reversal valve 11, which is adapted to exchange the stream during the
regeneration step, so as to regenerate the activated-carbon filter B in
countercurrent.
Advantageously, the blower 5 is functionally connected to an inverter
12, which is associated with a control device (not shown in the figures) and
is adapted to increase the speed of the blower 5 (and therefore the flow-rate
of the fluid medium through the discharge duct 3) during the step for
regeneration of the activated-carbon filter B.
The valves 4, 7, 9 and 10 must be gas-tight, and despite being shown
as single valves can of course be grouped in a three-way arrangement
Therefore, the system 1 described above has a single activated-carbon
filter B with discontinuous purification and operates according to four steps.
During the first step, or CO2 absorption step, the valves 4 and 10 are
open and the reversal valve 11 is in the normal position. The blower 5 draws

WO 2006/097217 PCT/EP2006/002034
5
air from the storage room C, sends it to the activated-carbon filter B and
returns purified air to the storage room c. Typically, the duration of this first
step is approximately 5-10 minutes. If an inverter 12 is used, during this
step a reduced speed of the blower 5 is used at the beginning of the step,
increasing it a few seconds before said step ends.
In the second step, or exchange step, the valves 7 and 10 are open and
the reversal valve 11 is still in the normal position; the blower 5 draws
external air and sends it to the activated-carbon filter B; said air, depleted of
its oxygen, is introduced in the storage room C. The duration of this second
step is on the order of 10-20 seconds.
The third step, or regeneration step, is performed with the valves 7
and 9 open and with the reversal valve 11 in the switching position. The
blower 5 draws external air from the valve 9, conveys it through the
activated-carbon filter B, and returns it outside. The duration of this step is
similar to the duration of the first step if the inverter 12 is present.
Otherwise, i.e., if the speed of the blower 5 is constant, it is convenient to
provide a duration which is slightly longer by approximately 10-20%.
In the fourth step, or decompensation step, the valves 4 and 9 are
open and the reversal valve 11 is in the normal position. The blower 5 draws
air from the storage room C by means of the valve 4 and sends it to the
activated-carbon filter B, and the air that passes through the activated-
carbon filter B is then expelled externally. The duration of this step is
approximately 10-20 seconds, depending on the flow-rate of the blower 5.
The cycle then resumes from the first step.
The diagrams shown in Figures 2 to 5 illustrate a system 1 with a dual
activated-carbon filter (A and B), which is therefore capable of performing
continuous purification of the air before it is introduced in the storage room
C.
The components are substantially the same ones shown in Figure 1,
but they are duplicated; the reference letter A designates the components

WO 2006/097217 PCT/EP2006/002034
6
related to the activated-carbon filter A and the letter B designates those
related to the other activated-carbon filter B.
In this case also, the blower 5 is associated with a reversal valve 11,
which is adapted to switch the flow during the regeneration step, so as to
regenerate the activated-carbon filters A and B in countercurrent.
Advantageously, the blower 5 is connected functionally to an inverter
12, which is associated with a control device (not shown in the figures) and
is adapted to increase the speed of the blower 5 (and therefore the flow-rate
of the fluid medium through the discharge duct 3) during the step for
regeneration of the activated-carbon filters A and B.
An additional fan 6b is also provided.
The system operates completely automatically and the steps are
controlled by a PLC device.
The operating cycle is performed in six steps, during which the fans 5
and 6b run constantly.
The first step (shown schematically in Figure 2) provides absorption
by the activated-carbon filter A and regeneration of the activated-carbon
carbon filter B. The valves 4a, 4d, 9a and 9b are open and the reversal valve
11 is in the normal position. The additional fan 6b draws air from the
storage room C and sends it to the first activated-carbon filter A, and at the
same time returns purified air into the storage room C. The blower 5,
optionally driven by the inverter 12 at a high frequency (for example 62 Hz,
a flow-rate which is approximately 20% higher than a normal frequency of
50 Hz) draws air from the outside and conveys it through the second
activated-carbon filter B for a period ranging from 5 to 10 minutes.
In the second step, or pre-switching step, the condition of the valves
remains unchanged, while the inverter brings the frequency of the speed
variator to the normal speed (50 Hz) for approximately 8-10 seconds.
In the third step, or first switching step (shown in Figure 3), the
valves 4b, 4c, 9a and 9b are open and the reversal valve 11 is in the

WO 2006/097217 PCT/EP2006/002034
7
switching position. The additional fan 6b draws air from the storage room C
and sends it to the second activated-carbon filter B, and the air contained in
said second activated-carbon filter B is expelled outside. The blower 5
draws air from the outside and sends it to the first activated-carbon filter A.
The oxygen-poor air contained in the first activated-carbon filter A is
returned to the storage room C. The duration of this step can range from 10
to 20 seconds depending on the flow-rate of the additional fan 6b and of the
blower 5.
The fourth step (shown schematically in Figure 4) provides
absorption by the activated-carbon filter B and regeneration of the
activated-carbon filter A. The valves 4c, 4b, 10a and 10b are open and the
reversal valve 11 is in the normal position. The additional fan 6b draws air
from the storage room C and conveys it toward the second activated-carbon
filter B, and at the same time returns purified air into the storage room C.
The blower 5, optionally controlled by the inverter 12 at a high frequency
(for example 62 Hz, a flow-rate which is approximately 20% higher than a
normal frequency of 50 Hz) draws air, conveying it toward the first
activated-carbon filter A for a period ranging 5 from to 10 minutes.
In the fifth step, or pre-switching step, the condition of the valves
remains unchanged, while the inverter brings the frequency of the speed
variator to the normal value (50 Hz) for approximately 8-10 seconds.
In the sixth step, or second switching step (shown in Figure 5), the
valves 4a, 4d, 10a and 10b are open and the reversal valve 11 is in the
switching position. The additional fan 6b draws air from the storage room C
and sends it to the second activated-carbon filter B, and the air contained in
said second activated-carbon filter B is expelled externally. The blower 5
draws air from the outside and sends it to the first activated-carbon filter A.
The oxygen-poor air contained in the first activated-carbon filter A is
returned to the storage room C. This step can last from 10 to 20 seconds,
depending on the flow-rate of the additional fan 6b and of the blower 5.

WO 2006/097217 PCT/EP2006/002034
8
The cycle then resumes from the first step.
The second and fifth steps are not indispensable for the operation of
the system 1.
The valves 4a, 4b, 4c, 4d and 9a, 9b, 9c and 9d can be grouped into
four three-way valves or into two four-way valves.
It has been found that a system according to the invention allows to
improve the efficiency of activated-carbon filters without the aid of
expensive injections of nitrogen or of oxygen absorbers. By improving
efficiency while keeping the other conditions equal, the introduced oxygen
is reduced..
All the characteristics of the invention indicated above as
advantageous, convenient or the like, might also be omitted or be replaced
with equivalents.
The invention thus conceived is susceptible of numerous
modifications and variations, all of which are within the scope of the
appended claims.
Thus, for example, all the valves that are used can be of the electrical
and/or pneumatic type and can be controlled by a control unit according to
preset programs.
Moreover, with reference to the embodiment with two activated-
carbon filters, nothing prevents reversing, in the system, the positions of the
blower 5 and of the additional fan 6b.
Moreover, the system might be provided with an oxygen absorption
filter which is designed to absorb either the oxygen of the air before it is
introduced in the controlled atmosphere environment/environments or the
oxygen that is present in the, or each, activated-carbon filter before the
passage of the air to be filtered.
In practice, the materials used, as well as the dimensions, may be any
according to requirements.
All the details may further be replaced with other technically

WO 2006/097217 PCT/EP2006/002034
equivalent elements.
The disclosures in Italian Patent Application No. VR2005A000034
from which this application claims priority are incorporated herein by
reference.

WO 2006/097217 PCT/EP2006/002034
10
CLAIMS
1. A system for suppressing carbon dioxide from controlled
atmosphere environments, comprising at least one activated-carbon filter,
which is connected to an intake duct and a discharge duct, said intake duct
and said discharge duct being adapted to introduce and extract air into and
from a storage room, at least one blower being provided along said
discharge duct, said blower having, upstream or downstream of said at least
one activated-carbon filter, in succession, a discharge duct which can be
controlled by a check valve, and a first valve, characterized in that said
blower is associated with a reversal valve, which is adapted to switch the
flow during the regeneration step so as to perform the regeneration of said at
least one activated-carbon filter in countercurrent.
2. The system for suppressing carbon dioxide according to claim 1,
characterized in that said at least one blower is functionally connected to an
inverter which is associated with a control device and is adapted to increase
the speed of said blower during said step for regeneration of said least one
activated-carbon filter.
3. The system for suppressing carbon dioxide according to one or
more of the preceding claims, characterized in that it comprises two
activated-carbon filters in parallel for continuous operation.
4. The system for suppressing carbon dioxide according to one or
more of the preceding claims, characterized in that it comprises at least one
filter for absorbing oxygen, which is designed to absorb either the oxygen of
the air before it is introduced in the controlled-atmosphere environment or
environments, or the oxygen that is present in the, or each, activated-carbon
filter before the passage of the air to be filtered.
5. The system for suppressing carbon dioxide according to one or
more of the preceding claims, characterized in that it comprises an
additional fan which is adapted to draw air from said storage room.
6. The system for suppressing carbon dioxide according to one or

WO 2006/097217 PCT/EP2006/002034
11
more of the preceding claims, characterized in that it comprises a respective
reservoir which is associated with each activated-carbon filter.

A system for suppressing carbon dioxide from controlled atmosphere environments,
comprising at least one activated-carbon filter, which is connected to an intake duct and
a discharge duct, which are adapted to introduce and extract air into and from a
storage room; at least one blower is provided along the discharge duct and has
upstream or downstream of the activated-carbon filter, in succession, a discharge duct
which can be controlled by a check valve, and a first valve, the blower being associated
with a reversal valve, which is adapted to switch the flow during the regeneration step
so as to perform the regeneration of the activated-carbon filter or filters in
countercurrent.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=tIjuJGsNmj6RNYpLjHfkPw==&loc=wDBSZCsAt7zoiVrqcFJsRw==

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Patent Number

277177

Indian Patent Application Number

3335/KOLNP/2007

PG Journal Number

48/2016

Publication Date

18-Nov-2016

Grant Date

15-Nov-2016

Date of Filing

07-Sep-2007

Name of Patentee

MARVIL ENGINERING S.R.L.

Applicant Address

VIA A. MANZONI, 43 20121 MILANO

Inventors:

#	Inventor's Name	Inventor's Address
1	MASSIMO MERCADINI	VIA KAHN, 21-39044 EGNA
2	IVANO VILLA	VIA GUNCINA, 1/D-39100 BOLZANO

PCT International Classification Number

B01D 53/04

PCT International Application Number

PCT/EP2006/002034

PCT International Filing date

2006-03-06

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	VR 2005A000034	2005-03-16	Italy