BOTTOM PART CONFIGURED FOR A DEVICE FOR COATING OR MIXING GRANULAR PRODUCTS, MORE IN PARTICULAR PEANUTS, WITH A SUBSTANCE

Abstract

The present invention relates to a device for coating and mixing granular products, in particular food products, more in particular peanuts, the device comprising a compartment defined by a rotary bottom part and a stationary circumferential side wall, the device further comprising: a product supply for supplying the products into the compartment, a substance supply for supplying a substance into the compartment, a drive for rotating the rotary bottom part about its substantially vertical axis, wherein the rotary bottom part and the stationary circumferential side wall comprise non-stick parts which define a substantial part of an inner surface of the compartment and which are manufactured from a non-stick material, wherein said non-stick parts are mechanically connected to the device via detachable connectors, allowing fast replacement of worn-out non-stick parts by new, same non-stick parts.

Claims

1. A bottom part, comprising a central bottom part and a circumferential bottom part which is annular and configured to extend around the circumference of the central bottom part, the central bottom part and the circumferential bottom part being partially or completely manufactured from or coated with a non-stick material, wherein the circumferential bottom part is configured to be detachably connected to the central bottom part and is configured to be replaced separately from the central bottom part, and wherein the bottom part is configured to be mechanically connected to a device for coating or mixing granular products with a substance via detachable connectors.

2. The bottom part according to claim 1, wherein the bottom part comprises a conical surface which extends outwardly, the conical surface being oriented at an angle of between 30 and 60 degrees relative to the horizontal, wherein a transition between the central bottom part and the circumferential bottom part is located along the conical surface.

3. The bottom part according to claim 1, further comprising a rotary dome shaped part which is partially or completely manufactured from or coated with a non-stick material, wherein the rotary dome shaped part is configured to be exchangeable and centrally positioned on the central bottom part, and wherein the rotary dome shaped part is constructed to rotate at a higher and opposite speed than the rest of the bottom part.

4. The bottom part according to claim 3, wherein the rotary dome shaped part has a diameter at the base of less than half of a diameter of a compartment of the device for coating or mixing granular products with a substance and more than one sixth of a diameter of the compartment of the device.

5. The bottom part according to claim 3, wherein the rotary dome shaped part is configured to be coupled with a spinning atomizer disk so that the rotary dome shaped part and the spinning atomizer disk rotate at the same speed, the spinning atomizer disk being positioned above the rotary dome shaped part.

6. The bottom part according to claim 1, wherein at a transition between the central bottom part and the circumferential bottom part, an outer, upper ridge of the central bottom part protrudes above an adjoining ridge of the circumferential bottom part.

7. The bottom part according to claim 6, wherein at the transition, the outer, upper ridge of the central bottom part protrudes over a distance of at least 0.5 millimetre above the adjoining ridge of the circumferential bottom part.

8. The bottom part according to claim 6, wherein at the transition, the outer, upper ridge of the central bottom part protrudes over a distance of between 1 and 1.5 millimetre above the adjoining ridge of the circumferential bottom part.

9. The bottom part according to claim 1, wherein the bottom part is partially or completely manufactured from or coated with high molecular weight polyethylene.

10. The bottom part according to claim 1, wherein the central bottom part is coated with a non-stick coating, which is polytetrafluoroethylene (PTFE), a SiO-based ceramic coating, a nickel based alloy coating, or Diamond Like Carbon.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0091] FIG. 1 shows a general isometric view of a device according to the invention.

[0092] FIG. 2a shows a cross-sectional side view of a device according to the invention.

[0093] FIG. 2b shows a top view of the device according to the invention.

[0094] FIG. 3 shows a cross-sectional side view of a detail of a device according to the invention.

[0095] FIG. 4 shows a cross-sectional side view of an air gap between a bottom part and a side wall.

[0096] FIGS. 5a and 5b show an isometric side view of an air gap between a bottom part and a side wall.

[0097] FIG. 6 shows an isometric side view of a door in a side wall of the device according to the invention.

[0098] FIG. 7 shows a top view of a door in a side wall of the device according to the invention.

[0099] FIG. 8a shows a top view of a door frame and a door in the side wall of the device according to the invention.

[0100] FIG. 8b shows a top view of a detail of a door frame at an upstream side in the side wall of the device according to the invention.

[0101] FIG. 8c shows a top view of a detail of a door frame at a downstream side in the side wall of the device according to the invention.

[0102] FIG. 8d shows a further enlarged top view of a detail of a door frame at an upstream side in the side wall of the device according to the invention.

[0103] FIG. 9 shows a scoop used in the device according to the invention.

[0104] FIG. 10a shows a non-stick insert panel in a flat state.

[0105] FIG. 10b shows a non-stick insert panel in a round state.

DESCRIPTION OF THE EMBODIMENTS

[0106] Turning to FIG. 1, an embodiment of the device 10 according to the invention is shown. The device 10 comprises a stationary circumferential side wall 11 which comprises an outer vertical side wall 12 which is generally manufactured from steel.

[0107] The stationary circumferential side wall 11 defines a cylindrical shape. The device 10 further comprises a lid 14 at the top. A product supply which may have the form of a hopper 16 is provided for supplying the granular products into the device from above.

[0108] Further, a substance supply 18 is provided which comprises a separate supply channel 20 for a liquid, in particular water, a dosing device 21 and a separate supply channel 22 for the powder. It is also possible that the substance supply 18 comprises more separate supply channels, for instance when multiple different powders or liquids are to be supplied separately.

[0109] The device further comprises an air discharge 24. Further, a door 26 for discharging the products is provided in the stationary circumferential side wall 11. The door is operated with an actuator 28.

[0110] A first electric drive 30 for driving a rotary bottom part is provided, and a second electric drive 32 is provided for driving an atomizer disk. The drives are explained further below. A connection 34 is provided in the side wall for a scoop which is also explained in more detail below.

[0111] Further, an inspection door 36 is provided in the side wall for inspecting, a space below the compartment and for cleaning and maintaining this space.

[0112] The device 10 is a batch coater. In use, a batch of products and substance is supplied into the device and processed for a processing time period. At the end of the time period, the coated products are discharged as a batch from the device.

[0113] The device 10 is suitable for coating granular products, in particular food products, more in particular peanuts.

[0114] Turning to FIG. 2a, a compartment 38 is defined by the stationary circumferential side wall 11, a bottom part 40 and the lid 14 at the top. The bottom part may also be referred to as a bottom disk 40. The compartment 38 is cylindrical, i.e. is circular in top view. The compartment may have a diameter of 50-70 cm. The stationary circumferential side wall 11 is substantially vertical, but it is conceivable that the stationary circumferential side wall 11 is conical and tapers outwardly in an upward direction. The bottom part 40 is rotary and coupled to the drive 30 via a first, outer drive shaft 42.

[0115] The bottom part 40 comprises a lowest region 44 which may be oriented horizontally. The bottom part 40 further comprises an inclined surface 46 which is also referred to as a conical surface 46. The conical surface extends upwardly and outwardly from the lowest region 44.

[0116] The point where the conical surface 46 starts to rise from the bottom region 44 typically lies at a distance 124 of to the radius of the compartment from a central axis 122 of the compartment. The vertical axis 122 may be fixed.

[0117] The central bottom part and the circumferential bottom part may be partially or completely manufactured from or coated with HMPE. It was found that this material provides good non-stick qualities which allow processing of the sticky mass of peanuts and substance. Moreover, HMPE was found to provide good resistance to wear against the abrasive action of the peanuts. Despite this resistance to wear, the bottom part was found to wear off relatively quickly. Alternatively, other non-stick coatings may be applied to the central bottom part, e.g. Teflon (polytetrafluoroethylene (PTFE)), SiO-based ceramic coatings, nickel based alloy coatings (Hastelloy), or DLC (Diamond Like Carbon).

[0118] The bottom part 40 is divided into a central bottom part 48 and a circumferential bottom part 50. In the present invention, the insight was developed that the circumferential bottom part 50 wears a lot due to the abrasive action of the products, in more in particular wears more quickly than the central bottom part. This resulted in the insight that it would be advantageous to divide the bottom part into two separate parts. The circumferential bottom part has been made to be easy replaceable by connecting it in a detachable manner via bolts to the central bottom part 48. It is noted that the central bottom part 50 itself is also replaceable and needs to be replaced from time to time.

[0119] When the circumferential bottom part needs to be replaced, the entire bottom part 40 is removed from the compartment by uncoupling it from the shaft 42 and lifting it from the compartment. The bolts 52 are then removed and the worn out circumferential bottom part is replaced with a new circumferential bottom part. Then the opposite procedure is followed to re-install the bottom part 40.

[0120] The device 10 further comprises an atomizer disk 58 for atomizing a liquid which is supplied to the compartment 38. The liquid supply comprises a channel 61 leading to a nozzle 60 positioned directly above the atomizer disk 58. The atomizer disk is driven by a shaft 43 which is provided inside the shaft 42. The atomizer disk is exchangeable.

[0121] Below the atomizer disk 58 and positioned centrally on the bottom is a dome shaped part 62. The dome shaped part 62 is rotary and forms part of the rotary bottom part 40.

[0122] The dome shaped part 62 is constructed to rotate at a higher and opposite speed than the rest of the rotary bottom part in order to keep the mixture of products and substance at a distance from the spinning atomizer disk and a shaft 43 which drives the spinning atomizer disk. Typically, the dome shaped part rotates at a speed of 2000-4000 rpm and the rest of the rotary bottom part is constructed to rotate at an opposite speed of 300-1000 rpm.

[0123] The dome shape part 62 keeps the mixture of products and substance at a distance from the shaft 43 which drives the atomizer disk 58. The dome shaped part typically has a diameter 63 at the base of less than one half of a diameter 120 of the compartment and more than one sixth of a diameter 120 of the compartment. The dome shaped part may have a height 65 of less than one third of its diameter at the base. A angle 67 at which the dome extends relative to the horizontal at the base may lie between 20 and 50 degrees.

[0124] The stationary circumferential side wall 11 comprises at least one non-stick insert panel 64 which is mechanically connected to the inside of the outer side wall 12. The non-stick insert panel 64 forms an inner surface of the stationary circumferential side wall 11. At least one non-stick insert panel (64) may be partially or completely manufactured from or coated with Teflon.

[0125] The outer side wall 12 is from stainless steel, which is the customary construction material in the food processing industry. The at least one non-stick insert panel 64 is partially or completely manufactured from or coated with a non-stick material. In particular Teflon was found to be a suitable non-stick material. The non-stick insert panel 64 is detachably mounted to the steel outer side wall 12 and is exchangeable.

[0126] The non-stick side panel 64 and the circumferential bottom part 50 form non-stick parts 64, 50 and form an inner surface of the compartment. The non-stick parts are mechanically connected to the device in a detachable manner, allowing replacement by new, same non-stick parts when the existing non-stick parts are worn out by abrasive action of the granular products.

[0127] The insert panel 64 rests on supports 66. The non-stick insert panel is curved. In particular, the insert panel 64 is a single panel which extends fully around the circumference of the compartment 38. In this way, a single seam 165 (or joint) is defined which extends vertically. A downstream end of the non-stick insert panel abuts an upstream end.

[0128] A scoop 70 is provided at the inner side of the side wall. A base 77 of the scoop is located at a distance 78 above an upper ridge 72 of the bottom part 40 and is mounted to the vertical wall 12. The distance may be 20 mm. The scoop has a curved guiding surface 71. The guiding surface extends substantially parallel to the side wall at the side wall and curves into the compartment. The scoop mixes the mass inside the compartment by redirecting a portion of the rotating mass into the center of the compartment. The scoop also shows the direction of rotation of the bottom part 40, which is clockwise when viewed from above. The scoop can be disconnected from the outside via the connection 34 shown in FIG. 1 and taken from the compartment, for instance for replacement. Multiple scoops may be provided.

[0129] The scoop 70 may have a position which in top view is about 60-120 degrees upstream of the door 26. The scoop has a double curvature and redirects a part of the flow inwardly and downwardly. The redirected part of the flow follows a helical trajectory when sliding along the surface 71 of the scoop. A further scoop 70 may be provided, in particular opposite the first scoop.

[0130] Below the bottom part 40, a space 74 is defined. An air supply hole 76 is provided in the stationary circumferential side wall 11 below the bottom part, for blowing air into the space 74 by a source of pressurized air. The space is closed at the bottom side by a bottom plate 75.

[0131] Turning to FIG. 2b, the separate supply channel 22 of the powder is located directly above the scoop 70. In this way, the powder which enters the compartment via the supply channel 22 falls directly on the redirected portion of the products and becomes mixed with the products instantly. Two supply channels 22 and two scoops 70 are provided.

[0132] Turning to FIG. 3, the atomizer disk 58 is shown in more detail. The atomizer disk comprises a threaded portion 78 configured to be screwed into a mating threaded member 79 via which it is connected to the shaft 43. The atomizer disk can be unscrewed from the shaft 43.

[0133] Turning to FIGS. 4 and 5, the door 26 is shown which in the closed position engages a threshold 27. An air gap 80 is provided between the circumferential bottom part 50 and the door 26 and the threshold 27. The air gap extends around the circumference of the rotary bottom part 40, i.e. the air gap is also present between the stationary circumferential side wall 11 and the rotary bottom part 40. In use, pressurized air is supplied into the space 74 below the compartment via the opening 76. The air then flows upward through the air gap 80 into the compartment. The air gap and the upward air flow create an air seal between the rotary bottom part 40 and the stationary circumferential side wall 11, which prevents any products from falling through the air gap.

[0134] A width 82 of the air gap is constant over a certain height 84. The height is measured from the upper and outer rim 89 of the circumferential bottom part to a point 87 on the outer side of the circumferential bottom part where the circumferential bottom parts turns away from the outer side wall 11 or the threshold 27. This height 84 allows the circumferential bottom part to wear, as is shown with the dashed lines 86. In use the abrasive action of the products gradually removes material from the circumferential bottom part 50. By providing the air gap with a constant width over a substantial part of the height 84, the air gap does not increase in size when the circumferential bottom part wears down.

[0135] The point 87 is about 1-2 mm lower than a ridge 95 of the threshold.

[0136] The constant width advantageously increases the effective life span of the circumferential bottom part. The height 84 typically is at least 5 mm, resulting in a life span of several weeks during normal operating conditions when coating peanuts. Without the constant width, the life span would be much less, because the air gap would quickly increase in size, resulting in a lower air velocity through the gap and as a result a leaking air seal.

[0137] The central bottom part 48 wears slower than the circumferential bottom part 50 and therefore has a longer life span, typically at least 10 weeks.

[0138] Turning in particular to FIGS. 5a and 5b, a transition 110 is provided between the central bottom part 48 and the circumferential bottom part 50. At the transition 110, an outer, upper ridge 112 of the central bottom part 48 protrudes over a distance 116 of at least 0.5, in particular between 1 and 1.5 millimetre above an adjoining ridge 114 of the circumferential bottom part 50. In the present invention the insight was developed that this protrusion prevents the circumferential bottom part 50 to wear at the transition. In use, the products move upwardly along the conical surface 46 in the direction of arrow 118. Because the products are hard enough to cause abrasive action, a flush transition was found to result in rapid wear at the transition and the protrusion prevents this.

[0139] Turning to FIG. 6, the door 26 is shown in the stationary circumferential side wall 11 of the device 10. A pneumatic or hydraulic cylinder 88 is provided to operate the door 26 via. The door pivots about a first vertical pivot axis 90 and a second vertical pivot axis 91. An intermediate member 92 is provided which pivots about the axis 90. The door itself pivots relative to the intermediate member about axis 91.

[0140] Turning to FIGS. 7 and 8a-8d, the door 26 fits in a frame 94 which has vertical posts 96. In use the products rotate in the clockwise direction, indicated with arrow 98. The vertical posts 96 adjoin the insert panel 64. At the upstream side 100 of the door, the vertical post of the frame is recessed over a distance 102 of at least 0.5 mm, in particular about 1 mm, relative to the insert panel 64. In this way, the mixture of products and substance pass the transition without inflicting damage to the vertical post of the frame. The door 26 itself is slightly recessed relative to the frame at the upstream side 100 for a same reason.

[0141] At the downstream side 101, the situation is reversed. The vertical post 96 of the frame is slightly recessed relative to the door and the insert panel 64 is slightly recessed relative to the vertical post 96 of the frame. The recess distance 102 between the insert panel 64 and the vertical post of the frame may each time be around 1 mm. The door has an inner face 105. A recess distance 104 between the vertical post of the frame and the door may be at least 0.5 mm and typically about 1 mm.

[0142] Turning to FIG. 9, the scoop 70 is shown. The scoop is configured to redirect a part of the rotating product flow. The scoop is partially or completely manufactured from or coated with HMPE. The scoop comprises two quick-couplings 108 which protrude through a hole in the side wall to the outside and are connected to the side wall via coupling 34. The quick couplings 108 allow fast replacement of the scoop.

[0143] At an upstream end 73, the scoop extends substantially parallel to the stationary circumferential side wall and curves inwardly in a direction of flow. The scoop may curve over an arc of at least 50 degrees, more in particular 70 degrees. An outer side of the scoop may be curved in order to match the form of the stationary circumferential side wall 11. The scoop may be configured to direct the portion of the flow slightly downwards.

[0144] Turning to FIGS. 10a and 10b, the non-stick insert panel 64 is shown separately and in a flat state in FIG. 10a and in the round state in FIG. 10b. The non-stick insert panel has a length 135 of 1700-1900 mm, in particular about 1800 mm and a width 136 of 350-450 mm, in particular about 400 mm. The non-stick insert panel 64 has a rectangular recess 130 which fits around the frame of the door. The recess 130 has a length of about 290 mm and a width (which in use is the height) of about 270 mm. An end 132 is configured to meet an opposite end 133 in an abutting manner when the insert panel 64 is inserted into the compartment against the outer side wall. A dashed line 134 indicates the level of the outer and upper rim 89 of the circumferential bottom part 50.

[0145] Operation

[0146] When the device is operated, a batch of granular products, in particular food products, more in particular nuts, even more in particular peanuts, is supplied into the compartment 38. The product may be metered into the device by a pre-set batch weight.

[0147] A quantity of water based liquid and a quantity of powder is supplied to the compartment. The water based liquid is supplied via the atomizer disk where it is atomized into spray of very fine droplets.

[0148] The water based liquid and the powder form a substance. The substance and the products are mixed by rotating the bottom part about its vertical axis of rotation, thereby creating centrifugal action. The rotation of the bottom part causes the products and the substance to become mixed. The mixture of products and substance moves upwards along the conical surface to the side wall and is turned back into the compartment by the scoop 70. This movement repeats itself.

[0149] In case of coated peanuts, the mixture is a sticky, abrasive mass.

[0150] After a certain time period which may vary on the requirements, the products are ready and discharged from the drum via the door 26.

[0151] Typically, when this sequence is repeated a number of times, the non-stick parts or at least some of the non-stick parts are worn out. This is due to the fact that the non-stick material is not a high strength material. It is strong enough for an acceptable number of operations, but not as strong as for instance stainless steel or another corrosion resistant alloy.

[0152] Therefore, after a certain period of time the worn-out detachable non-stick parts 50, 64 are removed and replaced by new, same non-stick parts. This replacement operation can be carried out quite easily and quickly. When the device has been fitted with replacement parts 50, 64, the operation can recommence.

[0153] The present invention is especially suitable for products which are hard enough to exert an abrasive action on non-stick materials such as Teflon and HMPE, and wherein the mixture of the granular products and the substance is a sticky, abrasive, mass which sticks to stainless steel.

[0154] Advantageously, at least one non-stick Teflon insert panel 64, a HMPE central bottom part 48 and/or a HMPE circumferential bottom part 50 may be cut to size with a CNC controlled cutting apparatus. This allows rapid replacement with vary narrow tolerances.

[0155] The coating process may be fully automated and may no longer require the supervision of a human operator.

[0156] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. Further, the terms and phrases used herein are not intended to be limiting, but rather, to provide an understandable description of the invention.

[0157] The terms a or an, as used herein, are defined as one or more than one. The term plurality, as used herein, is defined as two or more than two. The term another, as used herein, is defined as at least a second or more. The terms including and/or having, as used herein, are defined as comprising (i.e., open language, not excluding other elements or steps). Any reference signs in the claims should not be construed as limiting the scope of the claims or the invention.

[0158] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. As long as not stated otherwise features of different embodiments of the present invention can be combined with each other.