STRETCHING-SHAFT SCREENING DEVICE FOR SEPARATING INSECTS, IN PARTICULAR INSECT LARVAE, OR WORMS AND RESIDUAL MATERIAL, AND USE OF SUCH A STRETCHING-SHAFT SCREENING DEVICE

Abstract

A stretching-shaft screening device for separating insects, in particular insect larvae, or worms and residual material, is disclosed, having a screen that has a first screening portion and an adjoining second screening portion, wherein the mesh size in the first screening portion is smaller than the mesh size in the second screening portion. The invention also relates to the use of a stretching-shaft screening device for separating insects, in particular insect larvae, or worms and residual material.

Claims

1. A stretching-shaft screening device for separating insects—in particular, insect larvae—or worms and residual material, having a screen that has a first screening portion and an adjoining second screening portion, wherein the mesh size in the first screening portion is smaller than the mesh size in the second screening portion.

2. The stretching-shaft screening device according to claim 1, wherein the first screening portion has at least one screening mat, advantageously, several screening mats, further advantageously, 6 to 20 screening mats, and, particularly advantageously, 8 to 15 screening mats, and/or the second screening portion has at least one screening mat, advantageously, several screening mats, further advantageously, 1 to 20 screening mats, and, particularly advantageously, 1 to 10 screening mats.

3. The stretching-shaft screening device according to claim 2, wherein the mesh size of the at least one screening mat of the first screening portion is 60 mm.sup.2 to 110 mm.sup.2.

4. The stretching-shaft screening device according to claim 2, wherein the mesh size of the at least one screen mat of the second screening portion is 140 mm.sup.2 to 400 mm.sup.2.

5. The stretching-shaft screening device according to claim 2, wherein, in the first screening portion, the mesh size of one screening mat is different from the mesh size of another screening mat, and/or, in the second screening portion, the mesh size of one screen mat is different from the mesh size of another screen mat.

6. The stretching-shaft screening device according to claim 2, wherein the meshes of a screening mat have different mesh sizes.

7. The stretching-shaft screening device according to claim 1, wherein the screen length of the first screening portion is longer than the screen length of the second screening portion.

8. The stretching-shaft screening device according to claim 1, wherein at least the screen is arranged at an incline, wherein the inclination with respect to the horizontal is advantageously at most 25°, preferably 5° to 23°, and particularly preferably 10° to 15°.

9. The stretching-shaft screening device according to claim 1, wherein at least one retaining curtain is provided for partially retaining insects—in particular, insect larvae—or worms, wherein several retaining curtains are preferably provided.

10. The stretching-shaft screening device according to claim 9, wherein the at least one retaining curtain has a retaining height that corresponds at most to 0.95 times the height between the screen and a cover above the screen or an—in relation to the installation orientation of the stretching-shaft screening device—upper end of a region located above the screen.

11. The stretching-shaft screening device according to claim 1, wherein at least one separating device is provided for separating fine fractions and/or light fractions of the residual material, wherein the at least one separating device advantageously comprises a suction device or blowing device, wherein, further advantageously, the at least one separating device is arranged upstream of the screen in the transport direction of the screen.

12. The stretching-shaft screening device according to claim 1, wherein at least one rescreening device is provided for screening out screened fractions, wherein the at least one rescreening device is advantageously connected downstream of the first screening portion and/or downstream of the second screening portion.

13. A use of a stretching-shaft screening device—in particular, a stretching-shaft screening device according to claim 1—for separating insects—in particular, insect larvae—or worms and residual material.

14. The use according to claim 13, for screening live insects—in particular, live insect larvae—or live worms.

Description

[0055] The invention is explained in more detail below with reference to an exemplary embodiment and a drawing. In the drawing:

[0056] FIG. 1: shows a stretching-shaft screening device according to the invention in a schematic longitudinal section.

[0057] The stretching-shaft screening device 11 shown in FIG. 1 for separating live black soldier fly larvae (BSF larvae; Hermetia illucens) or live mealworms (e.g., Tenebrio molitor, Zophobas morio, or Alphitobius diperinus) and residual material has a screen 21 and a mechanism, not shown here, for moving the screen 21, which mechanism is known to be formed in such a stretching-shaft screening device 11. By means of this mechanism, the screen 21 is bent, stretched, and unloaded. In this case, the material located on the screen 21 is moved from a feed opening 12 to a delivery opening 14, and screening takes place at the same time.

[0058] The contents of the cultivation container, i.e., the larvae or mealworms with the residual material, are poured into a feed opening 12 of the stretching-shaft screening device. As a result of the movement of the screen 21, the material located on the screen 21 is moved from the feed opening 12 to a delivery opening 14, and screening takes place at the same time (see arrows).

[0059] The screen 21 has a first screening portion 22 having eight (8) screening mats 23 through 30. These screening mats 23 through 30 are replaceably fixed in the stretching-shaft screening device 11 so as to be interchangeable.

[0060] The mesh size of the screening mats 23 through 30 of the first screening portion 22 is 60 mm.sup.2 to 110 mm.sup.2. The screening mats 23 through 30 of the first screening portion 22 can all be of the same mesh size and/or mesh pattern.

[0061] In the present exemplary embodiment, the mesh size of one screening mat is different from the mesh size of another screen mat. For example, the screening mats 23, 27, and 30 have a mesh size of 3 mm×29 mm. By contrast, the mesh size of the screening mats 24 and 26 is 3.5 mm×30 mm. The screening mats 25, 28, and 29 have a mesh size of 2.5 mm×25 mm.

[0062] A screening mat 23 through 30 of the first screening portion 22 can have meshes of one mesh size or meshes of a different mesh sizes.

[0063] The screen 21 further has a second screening portion 32 having four (4) screening mats 33 through 36, wherein the second screening portion 32 is directly adjacent to the first screening portion 22. The screening mats 33 to 36 of the second screening portion 32 are replaceably fixed in the stretching-shaft screening device 11 so as to be interchangeable.

[0064] The mesh size of the screening mats 33 through 36 of the second screening portion 32 is 140 mm.sup.2 to 400 mm.sup.2. The screening mats 33 to 36 of the second screening portion 32 can all be of the same mesh size and/or mesh pattern.

[0065] In the present exemplary embodiment, the mesh size of one screening mat is different from the mesh size of another screen mat. For example, the screening mat 33 has a mesh size of 8 mm×30 mm. By contrast, the mesh size of the screening mat 34 is 12 mm×12 mm. The screening mat 35 has a mesh size of 15 mm×15 mm, and the screening mat 36 has a mesh size of 20 mm×20 mm.

[0066] A screening mat 33 through 36 of the second screening portion 32 can have meshes of one mesh size or meshes of different mesh sizes.

[0067] The horizontal screen length L1 of the first screening portion 22 is longer than the horizontal screen length L2 of the second screening portion 32.

[0068] In this exemplary embodiment, the screen 21 is arranged at an inclination β of 14° to the horizontal.

[0069] The screen 21 is covered by a cover 16 such that no screen material can escape from the stretching-shaft screening device 11.

[0070] In the region of the first screening portion 22, five (5) retaining curtains 41 are provided for partially retaining the insect larvae and residual material. In the present example, these retaining curtains 41 are arranged at uniform distances from one another and extend from the cover 16 vertically in the direction of the screen 21. Here, the retaining curtains 41 each have a vertical retaining height that corresponds to 0.75 times the height H of the space 42.

[0071] In the region of the second screening portion 32, two (2) retaining curtains 43 are provided for partially retaining the insect larvae and residual material. In the present example, these retaining curtains 43 are arranged in the front half—in relation to the transport direction—of the second screening portion 32. The retaining curtains 43 also extend vertically from the cover 16 in the direction of the screen 21.

[0072] The space 42 between the screen 21 (or center line 31 thereof) and the cover 16 is of a vertically-measured height H. In the present exemplary embodiment, the retaining curtains 41 each are of a vertical retaining height that corresponds to 0.7 times the height H of the space 42. In contrast, the retaining curtains 43 each are of a vertical retaining height that corresponds to 0.6 times the height H of the space 42.

[0073] In an embodiment not shown here, all retaining curtains 41 and 43 can be of the same vertical retaining height. Furthermore, the retaining curtains 41 in the first screening portion 22 and/or the retaining curtains 43 in the second screening portion 32 can also be of different vertical retaining heights.

[0074] A separating device 51, for separating fine fractions of the residual material, is provided in the region of the feed opening 12, and thus in the transport direction of the screen 21 in front of the screen 21. In this case, this separating device 51 comprises a suction device with which fine fractions—in particular, chitin—are separated before the screening. This suction device comprises a suction fan, the suction strength of which can be adjusted by means of a controller—in particular, a controller of the suction device.

[0075] Instead of or in addition to a suction device, the separating device 51 can comprise a blowing device. Such a blowing device comprises a fan, the blowing strength of which can be adjusted by means of a controller—in particular, a controller of the suction device.

[0076] The first screening portion 22 is followed by a first rescreening device 55 for the screening of screened fractions. The first rescreening device 55 has several screening mats 56—for example, seven (7) in this case. The mesh sizes and/or mesh patterns of the screening mats 56 are smaller than the mesh sizes and/or mesh patterns of at least a part of the screening mats 23 through 30 of the first screening portion 22, whereby fine fractions can still fall through the meshes of the first rescreening device 55, but screened insects, insect larvae, or worms are collected.

[0077] The second screening portion 32 is followed by a second rescreening device 65 for the screening of screened fractions—specifically, downstream of the delivery opening 14. The second rescreening device 65 has several screening mats 66—for example, three (3) in this case. The mesh sizes and/or mesh patterns are larger than the mesh sizes and/or mesh patterns of the screening mats 33 through 36 of the second screening portion 32, whereby residual material can still fall through the meshes of the second rescreening device 65, but insects, insect larvae, or worms located in the residual material are collected by said rescreening device 65.

[0078] There is also a third rescreening device 75 for separating the screened fractions of insects, insect larvae, or worms into different size classes downstream of the second screening portion 32. The third rescreening device 75 has several screening mats 66—for example, four (4) in this case. The mesh sizes and/or mesh patterns are smaller than the mesh sizes and/or mesh patterns of at least a part of the screening mats 33 through 36 of the second screening portion 32, whereby part of the insects, insect larvae, or worms still fall through the meshes of the third rescreening device 75, and the other part of the insects, insect larvae, or worms is separated therefrom.

LIST OF REFERENCE SIGNS

[0079] 11 stretching-shaft screening device

[0080] 12 feed opening

[0081] 14 delivery opening

[0082] 16 cover

[0083] 21 screen

[0084] 22 1st screening portion

[0085] 23 screening mat

[0086] 24 screening mat

[0087] 25 screening mat

[0088] 26 screening mat

[0089] 27 screening mat

[0090] 28 screening mat

[0091] 29 screening mat

[0092] 30 screening mat

[0093] 31 center line of 21

[0094] 32 2nd screening portion

[0095] 33 screening mat

[0096] 34 screening mat

[0097] 35 screening mat

[0098] 36 screening mat

[0099] 41 retaining curtain at 22

[0100] 42 space

[0101] 43 retaining curtain at 32

[0102] 51 separating device

[0103] 55 1st rescreening device

[0104] 56 screening mat of 55

[0105] 65 2nd rescreening device

[0106] 66 screening mat of 65

[0107] 75 3rd rescreening device

[0108] 76 screening mat of 75

[0109] L1 horizontal screen length of 22

[0110] L2 horizontal screen length of 32

[0111] H vertical height of 41 or 43

[0112] B inclination of 21