Sieving machine for food ingredients

Abstract

To provide a sieving machine capable of preventing degradation of the quality of ingredient paste due to excessive pressure when sieving the ingredient paste from steamed food ingredients such as chestnuts or sweet potatoes, while improving the efficiency of collecting high-quality ingredient paste.SOLUTION: A sieving drum having numerous through-holes on its outer peripheral surface for sieving ingredient paste is provided with an internal screw composed of a first screw portion and a second screw portion of different shapes. The upstream side of the sieving drum is closed, and the other end being the downstream side is detachably or openably closed. On the upstream side of the transfer within the sieving drum, the first screw portion, which is helically formed, and the second screw portion, which is helically formed and continuously downstream of the first screw portion, are rotatably provided. The transfer flow rate of the food ingredient in the first screw portion is set to be greater than that in the second screw portion. In addition, the upstream slope of the transfer path in the second screw portion is made gentle so that the food ingredient is pressed outward through the through-holes and converted into the ingredient paste.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a strainer for straining food ingredients such as steamed chestnuts and sweet potatoes to produce a paste. [Background technology]

[0002] Food ingredients such as chestnuts and sweet potatoes are strained into a paste using a strainer and widely used in Japanese and Western sweets, etc. A machine similar to the one used to strain food ingredients is known as the "Refined Okara Manufacturing Apparatus" described in Patent Publication No. 4202410. The "refined soy pulp production apparatus" described in this publication has a supply section 10, which serves as an inlet for soy pulp, at one end of a filter cylinder 6 fitted with a spiral screw 9, and while the soy pulp is transported through the filter cylinder 6, the fine soy pulp components are crushed by the action of the screw 9 and scraper 20 and discharged from the filter holes 7 (Patent Document 1).

[0003] The invention described in Patent Document 1 is a device that micronizes "okara" (soybean pulp) while transporting it with a screw 9 inside a filter cylinder 6, and discharges it through filter holes 7 formed in the filter cylinder 6. The shape of the spiral blades in the screw 9 is of a typical configuration, and it is said that they rub against the filter holes 7 to crush and micronize the soybean pulp particles. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4202410 Summary of the Invention [Problem to be solved by the invention]

[0005] The device described in Patent Document 1, "Method for producing refined soy pulp and refined soy pulp," has a structure in which, as shown in the figure, unrefined "soy pulp" fed into a supply section 10 is pressure-fed by the spiral blades of a screw 9 and discharged as "refined soy pulp" from a filter hole 7. During transportation, the unrefined "okara" is agitated and crushed, and at the same time, it is cut and subjected to a micronization process, a kind of kneading that promotes particle miniaturization. As is clear from the figure, the screw 9 installed inside the filter cylinder 6 is a typical spiral shape, and the outer surface of the scraper 20 sandwiched between the screw 9 is formed parallel to the inner surface of the filter cylinder 6, so while it is effective in transporting the "okara" from upstream to downstream, it cannot be expected to have a significant effect in discharging it from the filter holes 7 in a direction perpendicular or oblique to the transport direction. When using this device to strain chestnuts or sweet potatoes to obtain a fruit paste, the fruit paste discharged from the filter holes 7 is ineffective, and if an attempt is made to increase the discharge efficiency, the pressure will become too high during transport from upstream to downstream, and more will be discharged from the waste passage holes 24 than from the filter holes 7. If the food is stirred and crushed under conditions of excessive pressure, heat will be generated due to friction, and the food will become sticky, which may deteriorate its flavor.

[0006] The present invention has been made to solve the above-mentioned problems, and provides a machine that can improve the discharge efficiency of the fruit paste being strained, reduce the increase in pressure during transportation, and minimize the generation of heat due to friction, thereby preserving the flavor of the food. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention has the following configuration. 1. A screw with a spiral blade for transporting food ingredients from upstream to downstream is installed inside a cylindrical straining drum with a large number of through-holes on its outer surface. This screw is composed of a first screw section that transports food ingredients downstream, and a second screw section with a different spiral blade shape from the first screw section that extrudes the food ingredients outward through the holes. The first screw section and the second screw section are installed inside the straining drum with a small gap maintained between the outer surfaces of their spiral blades and the inner surface of the straining drum. 2. The first screw section is positioned upstream in the transfer direction, and the second screw section, whose spiral blade has the same twist direction as the first screw section, is positioned downstream in the transfer direction, and the transfer flow path of the first screw section (the passage through which the food ingredients are transferred) and the transfer flow path of the second screw section (the passage through which the food ingredients are transferred) are continuously connected, and a shaft section is protruded from the end of each screw section. The size of the transfer flow path is set so that the transfer flow rate of the food material in the first screw section is several times larger than the transfer flow rate in the second screw section. 3. The upstream end of the straining drum is closed by an upstream end plate, and a shaft protruding from the first screw section is supported on the upstream end plate, which is further removably connected to a drive shaft linked to a motor. The upstream end plate of the straining drum is removably fixed to the frame. 4. The downstream end of the straining drum is closed by a downstream end plate which has multiple peel discharge ports and can be opened and closed freely, and a shaft portion which protrudes downstream of the second screw portion is supported on it. 5. The transport flow path of the first screw section is formed in a shape that transports the food material downstream, and the transport flow path of the second screw section is formed in a shape that pushes the food material outward through the through-hole. 6. The transport flow path formed by the spiral blade of the second screw section has a cross section that is approximately V-shaped, and the inclination angle of the inclined surface facing downstream of the spiral blade is 15° to 45° with respect to the inner surface of the straining drum. 7. A hopper is provided at the food ingredient inlet located directly above the first screw section located upstream of the straining drum, and food ingredients fed into the hopper fall from the inlet into a transport flow path formed by the spiral blades of the first screw section rotating within the straining drum, and are then sequentially transported downstream by the spiral blades of the first screw section to the transport flow path of the second screw section. 8. As the food ingredients are transported downstream, they are pushed diagonally outward by the inclined surfaces formed on the spiral blades of the second screw section, and are discharged through the numerous through-holes on the outer periphery of the straining drum, dropping into a container installed below the straining drum. The through-holes are provided around almost the entire circumference in correspondence with the second screw section installed inside on the downstream side of the straining drum, so they are discharged not only from the lower through-holes but also from the upper through-holes. 9. The skins (residues) mixed in the food ingredients are larger than the holes in the straining drum, so they are not discharged through the holes, but are transported to the end of the transport flow path and discharged through the skin discharge hole provided in the downstream end plate. [Effects of the Invention]

[0008] With the above-mentioned configuration, the actual paste is transported downstream by the spiral blade of the first screw section and supplied to the second screw section, and while being transported downstream as the spiral blade of the second screw section rotates, it is gradually pushed out through the holes in the straining drum and strained, which improves the quality of the actual paste because it is tightly packed and there is less heat generated by friction. The fruit paste is efficiently extruded and strained through the through holes during transport in the downstream direction due to the action of the shape of the inclined surface formed on the downstream side of the spiral blade of the second screw section, so that a fruit paste with a fluffy texture and excellent flavor is efficiently obtained without becoming sticky. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of an embodiment of the present invention taken along a line parallel to the axis. [Figure 2] FIG. 2 is a plan view of FIG. [Figure 3]FIG. 2 is a left side view of FIG. 1. [Figure 4] FIG. 2 is an enlarged front view of the screw in FIG. 1. [Figure 5] FIG. 2 is a partially enlarged view of the second screw portion. [Figure 6] 1 is a cross-sectional view parallel to the axis of another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present invention will now be described with reference to FIGS. [Example]

[0011] The straining drum 1 in a strainer used to strain food ingredients W, such as steamed chestnuts, sweet potatoes, and pumpkins, is a rectangular plate approximately 1 to 2 mm thick with numerous small-diameter holes 2 formed by punching or other means. The diameter of these holes 2 is, for example, approximately 1 to 5 mm, and a size is selected to suit various conditions, such as the type of food ingredient W and the intended use of the strained fruit paste P. The holes 2 are not formed along the entire length of the straining drum, but rather in a portion corresponding to the length of the spiral blade 11a of the second screw section 11, which will be described later. The straining drum 1 is formed by rolling a rectangular plate with numerous holes 2 into a circle and welding the joints to form a hollow cylinder. The range in which the holes 2 are formed is length A in FIG. 2 , and they are not formed within the range of length B corresponding to the spiral blade 10a of the first screw section.

[0012] In FIG. 1, the right end of the straining drum 1, which is the upstream end in the transfer direction, is closed by an upstream end plate 3, and the upstream end plate 3 is held by a frame 4. The left end of the straining drum 1, which is the downstream end in the transfer direction, is open, to which a downstream end plate 5 is detachably attached. The downstream end plate 5 is provided with multiple skin discharge holes 6, through which skins (residue) of chestnuts, potatoes, etc. mixed in with the food material W are discharged. In FIG. 3, the skin discharge holes 6 are provided only in the lower part of the downstream end plate 5, but they may also be provided on the entire surface. The downstream end plate 5 is configured to be removable to facilitate cleaning of the interior of the straining drum 1 and the screw 9, which is installed inside the straining drum 1 and will be described later. The skin discharge holes 6 can be kept fully open or partially open or closed, depending on the situation. An inlet 7 for food ingredients W is provided above the straining drum 1 on the upstream side in the transport direction, and a hopper 8 is provided above the inlet 7 either integrally with or detachably attached to the drum.

[0013] A screw 9 is rotatably mounted inside the straining drum 1. This screw 9 is formed by a first screw section 10 located on the upstream side and a second screw section 11 located on the downstream side, which are continuously formed. The outer peripheral surface 10b of the spiral blade 10a of the first screw section 10 and the outer peripheral surface 11b of the spiral blade 11a of the second screw section 11 are each held with a small gap between them and the inner peripheral surface 1a of the straining drum 1. The first screw section 10 is formed so that the valley depth is deeper than the valley depth of the second screw section 11, allowing a greater amount of food material W to be transported downstream.

[0014] The valley bottom surface 10c of the first screw section 10 is tapered at the downstream end to form an inclined valley bottom surface 10d, and the spiral transport flow path S in the first screw section 10 is formed so as to communicate with the spiral transport flow path T of the second screw section 11.

[0015] A shaft portion 10e projects integrally from the axial center on the upstream side of first screw section 10, and this shaft portion 10e is rotatably supported on upstream end plate 3. A notch 10f is formed by cutting out half of the circumference at the tip of shaft portion 10e projecting from upstream end plate 3. A drive shaft 12 that rotates screw 9 has a notch 12a cut out around half the circumference at the tip in a shape corresponding to notch 10f formed on shaft portion 10e projecting from first screw section 10, and engagement between notches 10f and 12a enables screw 9 and drive shaft 12 to rotate integrally. Drive shaft 12 is supported horizontally on frame 4 by two bearings 13. A hollow-shaft motor 14 is attached to drive shaft 12, and rotation of motor 14 rotates screw 9 so as to transport food ingredients W downstream inside straining drum 1. The frame of the motor 14 is fixed to the mount 4. The shaft portion 10e of the first screw portion 10 and the drive shaft 12 may be connected by a known coupling (not shown).

[0016] 4 and 5, a shaft portion 11e is integrally provided to protrude from the axis of the downstream side of the second screw portion 11, and the shaft portion 11e is rotatably supported by the downstream end plate 5. As shown in Fig. 4, the shape of the second screw portion 11 is formed at a pitch P2 (P2 is set to half of P1 in the drawing) which is narrower than the pitch P1 of the spiral blades 10a in the first screw portion 10. The helical blade 11a of the second screw section 11 has a different shape from the helical blade 10a of the first screw section 10, and is formed wider than the helical blade 10a. This helical blade 11a continues from an outer peripheral surface 11b of width a to a first inclined portion 11c of width b inclined at a small angle α°, a second inclined portion 11f inclined at an angle θ°, and a valley bottom surface 11d. The angle β° is the inclination angle of the inclined surface 11g facing upstream formed by the helical blade 11a. The inclined surface 11g with an angle β° does not directly affect the discharge of the food ingredients W. The second inclined portion 11f at an angle θ° mainly functions to push out the food ingredients W from the through-holes 2, and the first inclined portion 11c at an angle α° functions to push out the food ingredients W that have adhered to the inner surface of the straining drum 1 and have not been discharged.

[0017] A container C for storing the actual paste P discharged from the through-hole 2 is installed below the downstream side of the straining drum 1, and an inclined peel discharge chute 15 is installed outside the downstream end plate 5, and a residue box D is installed at the outlet of the peel discharge chute 15.

[0018] In the above-described device, when motor 14 is started to rotate screw 9 in a predetermined direction and chunks of food ingredients W are sequentially fed from hopper 8 into inlet 7, the food ingredients W fall into straining drum 1. A first screw section 10 of screw 9 is disposed inside straining drum 1, and the food ingredients that fall into the spiral transfer flow path S of first screw section 10 are transported downstream (in the direction of arrow X) as first screw section 10 rotates. At this time, the transport of food ingredients W downstream is carried out by spiral blade 10a of first screw 10.

[0019] The food ingredients W transferred downstream by the spiral blade 10a of the first screw section 10 move into the flow path T of the second screw section 11. Because the transfer flow path T of the second screw section 11 is formed to have a smaller volume than the transfer flow path S of the first screw section 10, the food ingredients W sent by the spiral blade 10a of the first screw section 10 are compressed from the upstream side within the transfer flow path T of the second screw section 11, and are pressed against the inner surface 1a of the straining drum 1 by the action of the inclined surface 11f facing downstream of the spiral blade 11a of the second screw section 11, and are extruded in multiple rows as paste P through the through holes 2. In this embodiment, the food material transported to near the end of the second screw section 11 is not strained into a solid paste at one location under strong pressure, but is gradually extruded in multiple rows from the through holes 2 by the inclined surface 11f of the second screw section 11 during transport, thereby reducing the generation of stickiness and heat.

[0020] At the downstream end of the second screw section 11, skins H that are mixed in with the transported raw food material W without being pushed out through the through holes 2 are pushed out through the skin discharge holes 6 in the downstream end plate 5. The skin discharge holes 6 may be open all the time, but it is also possible to provide only the required number of skin discharge holes 6 that can be opened and closed freely (not shown) depending on the conditions of the raw food material W. The skins H mixed in with the raw food material W are larger in diameter than the through holes 2, and any particles larger than the through holes 2 will not be pushed out through the through holes 2 during transport. Therefore, the skins H are transported downstream and pushed out from the downstream end plate 5. The skins H fall through an inclined skin discharge chute 15 provided close to and below the downstream end plate 5 and are collected in the residue box D.

[0021] If a vibrating device (not shown) is provided in the hopper 8 to break down the lumps of food ingredients W that are added, the food ingredients W can be easily dispersed and introduced into the transport flow path S of the first screw 10, thereby improving the efficiency of transport by the first screw section.

[0022] FIG. 6 shows another embodiment in which the straining drum 21 is shorter than that of the previous embodiment, and a pipe 22 with the same inner diameter as the straining drum 21 is connected to the upstream side. The aforementioned screw 9 is installed inside this straining drum 21 and pipe 22. The through-hole 23 formed in the straining drum 21 corresponds to the length of the spiral blade 11a of the second screw section 11 of the screw 9 shown in FIG. 4, as in the previous embodiment. The length of the pipe 22 corresponds to the length of the spiral blade 10a of the first screw section. The straining drum 21 and pipe 22 are connected by a flange 24 fixed to the end of the straining drum 21 and a flange 25 fixed to the end of the pipe. The flanges 24 and 25 are fitted and fixed to prevent misalignment of the axes of the straining drum 21 and pipe 22. An upstream end plate 26 closing the upstream end of the pipe 22 supports the shaft portion 10e protruding from the first screw section 10. The upstream end plate 26 is fixed to the frame 4 by a metal fitting 28. The pipe 22 is supported by a support member 29 not only at the upstream end but also at the downstream end. The first screw section 10 is disposed inside the pipe 22, and the second screw section 11 is disposed inside the straining drum 21. A downstream end plate 27 is attached to the downstream end of the straining drum 21 to close the downstream end, and supports the shaft 11e protruding downstream of the screw 9, as in the previous embodiment. The downstream end plate 27 is provided with a number of peel discharge holes 31. In this embodiment, the straining drum 21 can be easily separated from the pipe 22 by disconnecting the flange 24 on the pipe 22 side from the flange 25 on the straining drum 21 side, and the straining drum 21 and the screw 9 can be easily removed for cleaning.

[0023] In the above embodiment, the shanks 10e and 11e are integrally protruded from both ends of the screw 9, but it is also possible to fix the screw by inserting the shaft into a shaft hole that penetrates the shaft center without protruding the shanks 10e and 11e. [Explanation of symbols]

[0024] 1. Straining drum 2. Through hole 3...Upstream end plate 5...Downstream end plate 6...Skin drainage hole 7...Inlet 9. Screw 10. First screw section 10a··Spiral blade 10e·Shaft part 11 Second screw section 11a Spiral blade 11e·Shaft part 12 Drive shaft 21 Straining drum 22 Pipe 23...Through hole 26...Upstream end plate 37...Downstream end plate P... Actual paste S...Transport channel T...transfer channel W...Food raw materials

Claims

1. A screw having a spiral blade for transporting food materials from upstream to downstream is rotatably mounted within a cylindrical straining drum having a large number of through-holes on its outer circumferential surface, the screw comprising a first screw section disposed upstream for transporting food materials downstream, and a second screw section disposed downstream for extruding the food materials transported by the first screw section outward through the large number of through-holes in the straining drum, the outer circumferential surface of each screw section being mounted within the straining drum with a small gap maintained between it and the inner circumferential surface, The first screw section is configured to transfer a flow rate of the food raw material greater than the second screw section, The upstream end of the strainer drum is closed by an upstream end plate, and the downstream end is closed by a downstream end plate provided with a plurality of peel discharge holes so as to be able to be opened and closed. The upstream shaft of the screw is supported by an upstream end plate, the downstream shaft is supported by a downstream end plate, and the upstream shaft is coupled to a motor which is a drive source, The upstream end plate is fixed to a frame, and the outer peripheral surface of the upstream side of the straining drum is partially opened to form a hopper serving as an inlet for the food ingredients, which is provided above the first screw section.

2. 2. A strainer for food ingredients as described in claim 1, wherein the spiral transfer flow path formed by the spiral blades of the first screw section is shaped to transfer the food ingredients in a downstream direction, and the spiral transfer flow path formed by the spiral blades of the second screw section is shaped to push the food ingredients outward.

3. 3. A strainer for food ingredients as described in claim 2, wherein the spiral transport flow path formed by the spiral blade of the second screw section has a cross section formed in an approximately V-shape, and the inclination angle of the inclined surface of the spiral blade facing downstream is formed at an angle of 15° to 45° with respect to the inner surface of the straining drum.

4. A pipe having an inner diameter matching the diameter of the cylindrical straining drum is detachably connected to the straining drum having a large number of through-holes on its outer periphery, and a screw having a spiral blade for transporting food materials from upstream to downstream is rotatably installed within the straining drum and the pipe, the screw comprising a first screw section disposed on the upstream side for transporting food materials downstream, and a second screw section disposed on the downstream side for extruding the food materials transported by the first screw section outward through the large number of through-holes in the straining drum, The first screw section is disposed inside the pipe, the second screw section is disposed inside the straining drum, the outer peripheral surface of the first screw section is fitted to the inner peripheral surface of the pipe with a minute gap therebetween, and the outer peripheral surface of the second screw section is fitted to the inner peripheral surface of the straining drum with a minute gap therebetween, The first screw section is configured to transfer a flow rate of the food raw material greater than the second screw section, The upstream end of the pipe is closed by an upstream end plate, and the downstream end of the straining drum is closed by a downstream end plate having a plurality of peel discharge holes in an openable and closable manner. The shaft portion protruding toward the upstream side of the screw is supported by an upstream end plate, the shaft portion protruding toward the downstream side is supported by a downstream end plate, and the upstream shaft portion is coupled to a motor which is a drive source, The upstream end plate is fixed to a frame, and the outer peripheral surface of the upstream side of the straining drum is partially opened to form a hopper serving as an inlet for the food ingredients, which is provided above the first screw section.

5. 5. A strainer for straining food ingredients as described in claim 4, wherein the spiral transfer flow path formed by the spiral blades of the first screw section is shaped to transfer the food ingredients in a downstream direction, and the spiral flow path formed by the spiral blades of the second screw section is shaped to push the food ingredients outward.

6. 6. A strainer for food ingredients as described in claim 5, wherein the spiral transport flow path formed by the spiral blade of the second screw section has a cross section formed in a substantially V-shape, and the inclination angle of the inclined surface of the spiral blade facing downstream is formed at an angle of 15° to 45° with respect to the inner surface of the straining drum.

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