Patent Description:
<CIT> discloses a cyclone separation system for separating live insects carried by an air stream, comprising a main cyclone chamber having a top chamber part and a conical shaped bottom chamber part. The top chamber part is connected to one or more intake channels each of which is arranged for connection to a primary air source providing an air stream comprising live insects. The bottom chamber part is connected to a discharge nozzle comprising a discharge end having a main discharge conduit for discharging the live insects from the cyclone separation system, wherein the discharge end comprises an air injection member for connection to a secondary air source and wherein the air injection member is configured to inject air back into the discharge nozzle.

<CIT> discloses an Insect Production Superstructure Systems (IPSS) to produce insects for human and animal consumption, and for the extraction and use of lipids for applications involving medicine, nanotechnology, consumer products, and chemical production with minimal water, feedstock, and environmental impact. The IPSS may comprise a cyclone separation system for separating live insects carried by an air stream.

Patent application <CIT> discloses a centrifugal separator for separating and collecting dust or other solid particles from air and gases, and of the class in which the dust-laden air or gas is propelled into a vessel in such a manner as to create therein a vortical motion.

The present invention aims to provide a cyclone separation system for separating live insects from an air stream, such as neonate larvae, wherein the cyclone separation system allows for efficient and reliable batch wise discharge of live insects from the cyclone separation system whilst keeping the live insects alive and preventing that the live insects stick or adhere to internal walls of the cyclone separation system. The cyclone separation system is ideally suited for automated live insect processing facilities.

According to the present invention, a cyclone separation system is provide as mentioned in the preamble above comprising a main cyclone chamber having a top chamber part and a conical shaped bottom chamber part, wherein the top chamber part is connected to one or more intake channels each of which is arranged for connection to a primary air source providing a primary air stream carrying live insects.

A discharge nozzle is provided having an intake end and a discharge end, wherein the intake end is connected to the bottom chamber part, and wherein the discharge end comprises a discharge channel for discharging the live insects from the cyclone separation system.

The discharge end comprises an air injection member for connection to a secondary air source providing a secondary air stream to the air injection member, wherein the air injection member comprises an air chamber for connection to the secondary air source, and a plurality primary air injection channels fluidly connecting the air chamber and the discharge channel. Each of the primary air injection channels is arranged to provide an injected upstream air flow in an upstream direction back into the discharge nozzle for stopping the discharge of the separated live insects.

The discharge nozzle comprises an inner wall part extending between the intake end and the discharge channel, and wherein the inner wall part comprises a plurality of elongated secondary air injection channels fluidly connected to the air chamber and extending from the discharge channel in the upstream direction. Each of the secondary air injection channels is arranged to provide an injected lateral air flow along the inner wall part.

According to the present invention, the air injection member of the discharge end is configured for injecting air back into the discharge nozzle, i.e. in the upstream direction, so that separated live insects in the discharge nozzle moving in downstream direction can be stopped and suspended or cushioned in air by the injected upstream air flow. Through the upstream air flow, the discharge of live insects can be stopped and as such the air injection member acts like a controllable air valve. Furthermore, the upstream air flow reduces damage to live insects and minimizes clump formation of live insects in the discharge nozzle.

The plurality of elongated secondary air injection channels are particularly advantageous for further reducing clump formation on the inner wall part by virtue of lateral air flow provided by the secondary air injection channels. Each of the secondary air injection channels is capable of inducing a distributed vortical air flow along the inner wall part so that clumps of live insects can be removed.

Reference is made to <FIG>, showing a schematic view of a cyclone separation system <NUM> according to an embodiment of the present invention, and to <FIG> showing various views of the discharge nozzle <NUM> and embodiments thereof as outlined above.

The cyclone separation system <NUM> of the present invention comprises a main cyclone chamber <NUM> having a top chamber part <NUM> and a conical shaped bottom chamber part <NUM>, wherein the top chamber part <NUM> is connected to one or more intake channels C each of which is arranged for connection to a primary air source providing a primary air stream A1 carrying live insects. In an embodiment, an auxiliary intake channel Ca may be provided to e.g. further control vortex generation in the cyclone separation system <NUM> than only to depend on the one or more intake channels C for supplying air to the top chamber part <NUM>.

A discharge nozzle <NUM> is provided having an intake end <NUM> and a discharge end <NUM>, the intake end <NUM> being connected to the bottom chamber part <NUM>, and wherein the discharge end <NUM> comprises a discharge channel <NUM> for discharging the live insects from the cyclone separation system <NUM>.

The discharge end <NUM> comprises an air injection member <NUM> for connection to a secondary air source (not shown) providing a secondary air stream A2 to the air injection member <NUM>, wherein the air injection member <NUM> comprises an air chamber <NUM> for connection to the secondary air source. In an exemplary embodiment, the air injection member <NUM> comprises an air inlet 9a a for connecting to the secondary air source and wherein the air inlet 9a is fluidly (gaseous) connected to the air chamber <NUM>, see e.g. <FIG>.

The air injection member <NUM> further comprises a plurality of primary air injection channels <NUM> fluidly connecting the air chamber <NUM> and the discharge channel <NUM>, wherein each of the primary air injection channels <NUM> is arranged to provide an injected upstream air flow F in an upstream direction U back into the discharge nozzle <NUM> for stopping the discharge of separated live insects.

As further depicted in the <FIG>, <FIG>, <FIG>, the discharge nozzle <NUM> comprises an inner wall part <NUM> extending between the intake end <NUM> and the discharge channel <NUM>, and wherein the inner wall part <NUM> comprises a plurality of elongated secondary air injection channels <NUM>, i.e. extending through the inner wall part <NUM>, fluidly connected to the air chamber <NUM> and extending from the discharge channel <NUM> in the upstream direction U. Referring to <FIG>, each of the secondary air injection channels <NUM> is arranged to provide an injected lateral air flow V along the inner wall part <NUM>.

According to the present invention, the air injection member <NUM> of the discharge end <NUM> is configured for injecting air back into the discharge nozzle <NUM>, i.e. in the upstream direction U. In doing so, separated live insects in the discharge nozzle <NUM> moving in downstream direction D can be stopped and suspended/cushioned in the injected upstream air flow F. Furthermore, the upstream air flow F reduces damage to live insects and minimizes clump formation of live insects in the discharge nozzle <NUM>. The injected upstream air flow F may be provided temporally to also stop the discharge of live insect temporarily.

The plurality of elongated secondary air injection channels <NUM> are particularly advantageous for further reducing clump formation on the inner wall part <NUM> by virtue of the lateral air flow V provided by the secondary air injection channels <NUM> when in use. Each of the secondary air injection channels <NUM> is capable of inducing a distributed lateral flow or air curtain along its upward length in the upstream direction U. The lateral air flow that can be provided by each of the secondary air injection channels <NUM> may be seen as a vortex/vortical flow along the inner wall part <NUM>.

It is worth noting that the primary and secondary air injection channels <NUM>, <NUM> will operate simultaneously when in use as they are both connected to the air chamber <NUM>. So when the air injection member <NUM> is activated, the upstream air flow F and the lateral air flow V occur simultaneously when the secondary air stream A2 is provided to the air chamber <NUM>.

Referring to <FIG>, in an embodiment, each of the secondary air injection channels <NUM> has a height H3 of at least <NUM>% of a height H1 of the inner wall part <NUM>. This embodiment ensures that a distributed lateral air flow V of sufficient height is provided, as measured from the discharge channel <NUM> in upstream direction U, for removing clumps of live insects. In further embodiments the height H3 of each of the secondary air injection channels <NUM> lies between <NUM>% and <NUM>% of the height H1 of the inner wall part <NUM>. The height H3 of each secondary air injection channel <NUM> may be chosen based on expectations and/or experience where clumps or contamination of live insects may develop along the inner wall part <NUM> near the discharge channel <NUM> and in the upstream direction U therefrom. In an exemplary embodiment, a common or same height H3 may be chosen for each of the secondary air injection channels <NUM>, so that the lateral air flow V provided by each secondary air injection channel <NUM> exhibits a similar flow profile and intensity along the inner wall part <NUM> to achieve uniform cleaning thereof.

In another embodiment, the air chamber <NUM> has a height H2 equal to or larger than the height H3 of each secondary air injection channel <NUM>, so that the air chamber <NUM> is able to optimally provide the lateral/vortical air flow V over the entire height H3 of each of the secondary air injection channels <NUM>. It is worth noting that in this embodiment the air chamber <NUM> has a height H2 equal to or larger than the height H3 of each secondary air injection channel <NUM> where the air chamber <NUM> connects to a secondary air injection channel <NUM>. That is, it is conceivable that in an embodiment, see <FIG>, the air chamber <NUM> between e.g. two secondary air injection channels <NUM> exhibits a height H2 that is less than the height H3 of the two secondary air injection channels <NUM>. As long as the height H2 of the air chamber <NUM> is equal to or larger than the height H3 of each secondary air injection channel <NUM> when the air chamber <NUM> connects thereto, then this will ensure optimal lateral/vortical air flow V along the height H3 of each of the secondary air injection channels <NUM>.

In light of <FIG>, <FIG>, another point to note is that, in exemplary embodiments depicted, the air chamber <NUM> fully encircles the discharge channel <NUM> and the inner wall part <NUM> up to height H2, so that the air chamber <NUM> is connected to each of the primary and secondary air injection channels <NUM>, <NUM>. Furthermore, the plurality of primary and secondary air injection channels <NUM>, <NUM> form a circumferential spaced apart arrangement of primary and secondary air injection channels <NUM>, <NUM> distributed around the discharge channel <NUM> and the inner wall part <NUM> respectively.

As further shown in <FIG>, in an embodiment, each of the secondary air injection channels <NUM> is arranged at an acute angle β with respect to the inner wall part <NUM>. That is, in this embodiment each of the secondary air injection channels <NUM> extends through the inner wall part <NUM> at an acute angle with respect thereto. As a result, the lateral or vortical air flow V will exhibit a tangential/parallel flow path along the inner wall part <NUM> for improved removal of any clumps of live insects that may be present thereon. The smaller the acute angle β, the more tangential/parallel the lateral air flow V will be, hence further improved removal of clumps.

In <FIG> it is further seen that in an embodiment each of the secondary air injection channels <NUM> may be laterally curved, i.e. sideways curved in a direction substantial parallel to the inner wall part <NUM>. So in this embodiment each of the secondary air injection channels <NUM> extends along a particular contour of the inner wall part <NUM> to provide for optimized tangential/parallel lateral air flow V with respect to the inner wall part <NUM>.

In an exemplary embodiment as shown in <FIG>, the inner wall part <NUM> is funnel shaped extending from a substantially circular intake end <NUM> to the discharge channel <NUM>, and wherein the discharge channel <NUM> is substantially rectangular, i.e. being slit shaped. That is, in this embodiment the intake end <NUM> is substantially circular and wherein the discharge channel <NUM> is substantially rectangular (slit shaped), and wherein the inner wall part <NUM> is funnel shaped and extends from the substantially circular intake end <NUM> to the substantially rectangular discharge channel <NUM>. Then, a first secondary air injection channel 13a of the plurality of secondary air injection channels <NUM> extends from a first shortest side 8a of the discharge channel <NUM> in the upstream direction U and wherein a second secondary air injection channel 13b of the plurality of secondary air injection channels <NUM> extends from an opposing second shortest side 8b of the discharge channel <NUM> in the upstream direction U.

In this embodiment, the intake end <NUM> connects to the conical shaped bottom chamber part <NUM> in which, during operation, live insects move in a vortex flow in the downstream direction D, and continue to do so as they near the substantially rectangular discharge channel <NUM>. As will be discussed in further detail later, the substantially rectangular discharge channel <NUM> facilitates accurate counting of live insects when discharged through the discharge channel <NUM>.

Due to the transition from a vortical flow of live insects along the inner wall part <NUM> into the discharge channel <NUM> may cause clump formation at the inner wall part <NUM> where it transitions to or engages the first and second shortest sides 8a, 8b of the discharge channel <NUM>. By having the first secondary air injection channel 13a extending from the first shortest side 8a and the second secondary air injection channel 13b extending from the opposing second shortest side 8b allows clump removal from the inner wall part <NUM> where it transitions to the first and second shortest sides 8a, 8b. Advantageously, this embodiment also prevents clump formation a the first and second shortest sides 8a, 8b as well.

As mentioned earlier, in an embodiment each of the secondary air injection channels <NUM> may have a height H3 of at least <NUM>% of a height H1 of the inner wall part <NUM>, and in further embodiments the height H3 of each of the secondary air injection channels <NUM> may be chosen between <NUM>% and <NUM>% of the height H1 of the inner wall part <NUM>. The height H3 of each secondary air injection channel <NUM> may be chosen based on expectations and/or experience where clumps of live insects may develop along the inner wall part <NUM> near the discharge channel <NUM> and in the upstream direction U therefrom. Now, when during operation live insects move in vortex/vortical flow in the downstream direction D and approach the substantially rectangular discharge channel <NUM>, there may be clump formation or contamination of live insects near the first and second shortest sides 8a, 8b of the discharge channel <NUM>. By choosing the height H3 of both the first and secondary air injection channels 13a, 13b to substantially match a transition height along which downward flow of live insects transitions from vortex/vortical flow to substantially non-vortex flow into the discharge channel <NUM>, then this ensures that clump formation near the first and second shortest sides 8a, 8b can be removed adequately through injected lateral air flow V by the secondary air injection channels 13a, 13b. As also depicted in <FIG>, in an advantageous embodiment, each of the first and shortest sides 8a, 8b of the discharge channel <NUM> is a rounded, curved or arched side, e.g. substantially semi-circular. The rounded/curved sides 8a, 8b provides for a smoother transition between the inner wall part <NUM> and the discharge channel <NUM>, thereby reducing turbulent air flow and violent movement of live insects along the inner wall part <NUM> where it transitions to the first and second shortest sides 8a, 8b. As a result, live insects moving into the discharge channel <NUM> are not damaged so that survival rates of live insects increase. In addition, clump formation is further reduced because of the smoother transition offered by the rounded sides 8a, 8b.

As outlined earlier, the discharge nozzle <NUM> is able to temporarily stop discharge of live insects through the discharge channel <NUM> by temporarily injecting the upstream air flow F by means of the plurality of primary air injection channels <NUM>. At the same time, the lateral air flow is injected by the plurality of secondary air injection channels <NUM>, thereby preventing clogging and clump formation of live insects at the inner wall part <NUM> of the discharge nozzle <NUM>.

Now, during operation of the cyclone separation system <NUM>, an inner air vortex and an outer air vortex exist concentrically in the top chamber part <NUM>, the conical shaped bottom part <NUM>, as well the discharge nozzle <NUM>. The outer vortex carries live insects and moves in downward direction D, the inner air vortex is clean from live insects and ascends in upstream direction U.

The height at which suspension of live insects in the discharge nozzle <NUM> occurs as well as maintaining as much vortex air flow in the discharge nozzle <NUM> as possible can be controlled by the rate at which the inner air vortex moves in upstream direction U.

With reference to <FIG>, <FIG>, to provide finer control on the inner vortex, an embodiment is provided wherein the cyclone separation system <NUM> further comprises an air exhaust part <NUM> arranged on the top chamber part <NUM>, wherein the air exhaust part <NUM> comprises an adjustable IRIS valve <NUM> configured to regulate a flow rate of ascending exhaust air from the top chamber part <NUM>. Here, the ascending exhaust air can be seen as air from the inner air vortex moving in the upstream direction U and exiting through the air exhaust part <NUM>. The IRIS valve <NUM> is advantageous as it provides a centralised adjustable passage <NUM> having an adjustable valve diameter Dv that aligns with the inner air vortex when the cyclone separation system <NUM> is in operation.

Flow rate adjustment by the IRIS valve <NUM> influences e.g. the height at which suspension of live insects in the discharge nozzle <NUM> during (temporary) activation of the air injection member <NUM> occurs as well as the quality of outer vortex air flow in the discharge nozzle <NUM> carrying the live insects. The height at which suspension may take place inside the discharge nozzle <NUM> is schematically depicted in <FIG>, by the imaginary separation line L upstream/above the discharge channel <NUM>.

Therefore, the IRIS valve <NUM> in conjunction with the plurality of primary and second air injection channels <NUM>, <NUM> allows improved control on how suspension of live insects in the discharge nozzle <NUM> occurs and to prevent clump formation and contamination of the inner wall part <NUM>.

<FIG> and <FIG> depict an embodiment wherein the air exhaust part <NUM> comprises a cylindrical lower portion <NUM> arranged between the IRIS valve <NUM> and the top chamber part <NUM>, thereby allowing that a laminar flow behaviour can be achieved when ascending exhaust air from the top chamber part <NUM> approaches the IRIS valve <NUM>. This laminar flow behaviour can be advantageous for accurate and reliable flow measurement purposes across the IRIS valve <NUM>. In an exemplary embodiment, the cylindrical lower portion <NUM> has a height H4 of at least <NUM> to <NUM> times of a maximum inner diameter of the cylindrical lower portion <NUM> for achieving sufficient laminar flow behaviour of ascending exhaust air approaching and flowing through the IRIS valve <NUM>.

For accurate control and monitoring of vortex behaviour in the cyclone separation system <NUM>, an exemplary embodiment is provided wherein the IRIS valve <NUM> comprises an adjustable diaphragm <NUM> providing the adjustable valve diameter (Dv), a first pressure sensor (19a) on an intake side of the diaphragm <NUM>, and a second pressure sensor (19b) on an exhaust side of the diaphragm <NUM>.

Returning to <FIG>, the cyclone separation system <NUM> allows for a batch wise filling process wherein a container <NUM> is placed underneath the discharge nozzle <NUM> from which live insects are discharged for a particular amount of time. The discharge is temporarily halted by actuation of the air injection member <NUM> when a required amount of live insects has been collected in the container <NUM>. As the air injection member <NUM> halts discharge, the container <NUM> is removed and another container <NUM> is placed underneath the discharge nozzle <NUM> so that the filling process can continue.

To allow for an efficient batch wise filling process of containers, an embodiment is provided wherein the cyclone separation system <NUM> further comprises a camera-based counting system <NUM> arranged at/below the discharge end <NUM> of the discharge nozzle <NUM> for counting live insects being discharged through the discharge end <NUM>. A transportation system <NUM> is provided and configured to move the yet to be filled container <NUM> from an upstream position p1 at which the container <NUM> is positioned before the discharge end <NUM>, to a discharge position p2 at which the container <NUM> is arranged underneath the discharge end <NUM>, to a downstream position p3 at which the container <NUM> is positioned after the discharge end <NUM>. The transportation system <NUM> comprises an upstream weight sensor <NUM> at the upstream positioned p1 and a downstream weight sensor <NUM> at the downstream position p3, wherein each of the upstream and downstream weight sensors <NUM>, <NUM> are configured to register a total weight of the container <NUM> when positioned at the upstream or downstream position p1, p3 respectively.

In the above embodiment the number of live insects being discharged can be registered by the camera based counting system <NUM> and where the upstream and downstream weight sensors <NUM>, <NUM> allow determination of a weight difference between the total weight of the container <NUM> at the upstream position p1, so prior to filling, and the total weight of the container <NUM> at the downstream position p3, so when the container <NUM> has been filled and moved away from the discharge nozzle <NUM>. By using the camera based counting system <NUM> in conjunction with the upstream and downstream weight sensors <NUM>, <NUM> allows for accurate analysis as to the number of live insects being counted versus a corresponding weight thereof. This in turn allows a threshold to be accurately determined as to when the air injection member <NUM> should be activated for achieving a desired weight of live insects in the container <NUM> based on the number of live insects counted.

It is worth nothing that in an advantageous embodiment the camera based counting system <NUM> provides for improved count accuracy when the discharge channel <NUM> is chosen to be substantially rectangular as mentioned earlier. In particular, an elongated rectangular discharge channel <NUM> allows for a relatively thin "curtain" or layer of live insects to be discharged through the discharge end <NUM> during operation, so that live insects do not visually block each other in a line of view of the camera based counting system <NUM> for achieving an accurate count therefrom.

In an advantageous embodiment, the transportation system <NUM> may comprise a discharge weight sensor <NUM> at the discharge position p2, so that the total weight of the container <NUM> as it is being filled can be monitored in real time and as such may further aid in determining the aforementioned threshold.

Taking the above embodiments of the cyclone separation system <NUM> into account, a method will now be described of providing batches of live insects. In particular, according to the present invention a method is provided of providing batches of live insects comprising the steps of.

As mentioned above, the camera based counting system <NUM> in conjunction with the upstream and downstream weight sensors <NUM>, <NUM> allows for accurate analysis as to the number of live insects being counted versus a corresponding weight thereof. The total weight difference is a measure of the weight of live insects that have been discharged in the container <NUM>. Since a total weight difference is determined, the actual weight of the container <NUM> is not taken into account. As a result, the method is able to provide a batch wise process in which different containers <NUM> may exhibit different total weights when measured by the upstream weight sensor <NUM>. Weight variability of the container <NUM> is therefore allowed and provides for an advantageous embodiment wherein the step of a) further comprises providing the container <NUM> with feed for live insects. In this embodiment the container <NUM> may contain a particular amount of feed for live insects as it at arrives at the upstream position p1. Since the feed may exhibit some weight variability, the total weight difference determined is step g) will not include this weight variability of feed in the container <NUM> and so the threshold for activating the air injection member <NUM> can still be accurately determined.

Referring to <FIG>, to prevent live insects from missing the container <NUM> when being discharged from the discharge end <NUM>, an embodiment is provided wherein the discharge nozzle <NUM> further comprises a discharge guiding member <NUM> mounted to/underneath the discharge end <NUM> of the discharge nozzle <NUM>. The discharge guiding member <NUM> comprises an expanding guiding channel <NUM> fluidly coupled to the discharge channel <NUM> for receiving live insects therefrom when the cyclone separation system <NUM> is in operation. In this embodiment the guiding channel <NUM> expands in the downstream direction D as depicted. This embodiment allows live insects to follow a discharge path P1 out of the discharge channel <NUM> to be deflected by the guiding channel <NUM> and to subsequently follow a deflected discharge path P2 into the container <NUM>.

In an advantageous embodiment, the discharge guiding member <NUM> may further comprise a lower circumferential/peripheral rim portion <NUM>, e.g. a circumferential/peripheral flange portion <NUM>, configured to engage an upper circumferential/peripheral rim portion 20a of the container <NUM> for sealing said container <NUM> during discharge of live insects. The lower circumferential rim or flange portion <NUM> can be used, for example, to cover a part of the container <NUM> when the guiding channel <NUM> is less wide than the container <NUM>, i.e. less wide than the upper circumferential/peripheral rim portion 20a of the container <NUM>. This ensures that the container <NUM> remains sufficiently sealed from above for preventing live insects escaping the container <NUM> when discharged therein.

As further depicted in <FIG>, the discharge guiding member <NUM> may be configured to provide a laterally extending slot/slit <NUM> when connected to the discharge end <NUM>. The laterally extending slot <NUM> allows counting of live insects by the camera based counting system <NUM> (not shown) when live insects exit the discharge channel <NUM>. In particular, a line of view of the camera based counting system <NUM> is able to extend through the laterally extending slot <NUM> to register live insects during operation. Advantageously, the laterally extending slot <NUM> may be sufficiently narrow to prevent live insects escaping there through.

When the discharge channel <NUM> is substantially rectangular, then the laterally extending slot <NUM> may preferably have a length that is equal to or larger than the longest sides of the rectangular discharge channel <NUM>, thereby ensuring that all live insects passing through the discharge channel <NUM> are observable by the camera based counting system <NUM>.

As further depicted in <FIG>, in an exemplary embodiment the discharge guiding member <NUM> comprises an upper connecting edge <NUM> configured to connect to the discharge end <NUM> of the discharge nozzle <NUM>, and wherein the upper connecting edge <NUM> comprises a recessed edge portion <NUM>, which provides for the laterally extending slot <NUM> when the upper connecting edge <NUM> engages the discharge end <NUM>.

Claim 1:
A cyclone separation system (<NUM>) for separating live insects carried by an air stream, comprising:
a main cyclone chamber (<NUM>) having a top chamber part (<NUM>) and a conical shaped bottom chamber part (<NUM>), wherein the top chamber part (<NUM>) is connected to one or more intake channels (C) each of which is arranged for connection to a primary air source providing a primary air stream (A1) carrying live insects;
a discharge nozzle (<NUM>) having an intake end (<NUM>) and a discharge end (<NUM>), the intake end (<NUM>) being connected to the bottom chamber part (<NUM>), and wherein the discharge end (<NUM>) comprises a discharge channel (<NUM>) for discharging the live insects from the cyclone separation system (<NUM>),
wherein the discharge end (<NUM>) comprises an air injection member (<NUM>) for connection to a secondary air source providing a secondary air stream (A2) to the air injection member (<NUM>), wherein the air injection member (<NUM>) comprises an air chamber (<NUM>) for connection to the secondary air source, and a plurality of primary air injection channels (<NUM>) fluidly connecting the air chamber (<NUM>) and the discharge channel (<NUM>), wherein each of the primary air injection channels (<NUM>) is arranged to provide an injected upstream air flow (F) in an upstream direction (U) back into the discharge nozzle (<NUM>) for stopping the discharge of the separated live insects,
and wherein the discharge nozzle (<NUM>) comprises an inner wall part (<NUM>) extending between the intake end (<NUM>) and the discharge channel (<NUM>), and wherein the inner wall part (<NUM>) comprises a plurality of elongated secondary air injection channels (<NUM>) fluidly connected to the air chamber (<NUM>),
characterised in that each of said plurality of elongated secondary air injection channels (<NUM>) is extending from the discharge channel (<NUM>) in the upstream direction (U), and is arranged to provide an injected lateral air flow (V) along the inner wall part (<NUM>).