Lotus root starch cyclone separation system
By designing a multi-stage hydrocyclone and a hydrocyclone pressurization mechanism, the problems of poor oxidation and separation of lotus root starch slurry were solved, achieving efficient separation, reducing production losses, and improving product quality and yield.
Patent Information
- Application Number
- CN202520154191.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-22
- Publication Date
- 2026-02-06
- Estimated Expiration
- 2035-01-22
AI Technical Summary
In existing technologies, the oxidation of lotus root starch slurry leads to a decline in product quality, poor separation effect, high waste rate, and increased production costs.
The design incorporates a multi-stage hydrocyclone system, including a receiving hopper, a primary hydrocyclone, a secondary hydrocyclone, and a dewatering device. The system utilizes a hydrocyclone pressurization mechanism to enhance flow rate and separation efficiency, enabling the separation of lotus root starch slurry with different particle sizes. A stirring mechanism prevents sedimentation, and a tertiary hydrocyclone further improves separation accuracy.
It increases the particle size of lotus root starch, ensuring a delicate texture, reducing production losses, increasing product output, simplifying the production process, and reducing costs.
Smart Images
Figure CN223875212U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to lotus root powder processing technical field, specifically relates to a lotus root powder cyclone separation system. BACKGROUND
[0002] The lotus root powder sold on the market is basically dry lotus root powder, which needs to be soaked with boiling water during eating, and the eating is relatively troublesome. In view of such a situation, some instant lotus root powder with relatively short storage period is developed on the market. Since the instant lotus root powder is lotus root powder that has been gelatinized, it does not need to be further dried and ground during production. If the lotus root powder is sequentially dried, ground, re-soaked and gelatinized, and then packaged, the production cost will obviously increase. Therefore, the instant lotus root powder currently basically passes through grinding after being crushed, and then the ground lotus root powder slurry is subjected to multiple standing and filtration separation, and finally gelatinization treatment.
[0003] The ground lotus root powder slurry is subjected to multiple standing and filtration separation, which is troublesome for wet powder as a whole, and needs a long standing time. In the process of standing and re-washing and filtration, the substances in the lotus root powder are prone to oxidation reaction with oxygen in the air, resulting in easy yellowing and blackening of the lotus root powder obtained in the later period, which affects the quality of the instant lotus root powder. This reason also leads to the main reason for the dark color of the conventional dry lotus root powder after soaking. At present, in order to reduce the oxidation of lotus root powder, some citric acid or other inhibitors are generally added to the lotus root powder slurry obtained by grinding to inhibit the activity of anthocyanins and polyphenol oxidase in the lotus root powder slurry, so as to avoid oxidation of the lotus root powder. However, such an operation method will cause the taste of the instant lotus root powder to be poor. There is another way to grade the lotus root powder slurry in the industry, that is, to use a cyclone to perform cyclone grading on the lotus root powder slurry, so that the oxidation of the lotus root powder slurry by oxygen can be reduced in a closed environment. However, the structure of the current cyclone grading equipment is relatively simple, and the particle sizes of lotus root powder particles of different grades after crushing and grinding of fresh lotus root are not much different, resulting in poor separation effect of the multi-stage cyclone separation, high product waste rate and low product yield. UTILITY MODEL CONTENTS
[0004] In order to overcome one of the deficiencies of the prior art, the purpose of the utility model is to provide a lotus root powder cyclone separation system, which can separate lotus root powder slurries of different particle sizes, ensure the quality of the product, and reduce production loss.
[0005] To solve the above problems, the technical scheme adopted by the utility model is as follows:
[0006] A taro powder cyclone separation system for classifying the taro powder slurry discharged by a fresh taro crushing and grinding device, comprising a receiving bin, a first cyclone and a second cyclone, the receiving bin being used for receiving the taro powder slurry discharged by the fresh taro crushing and grinding device; the first cyclone is communicated with the output end of the receiving bin; the overflow port of the first cyclone is communicated with the material inlet of the second cyclone through a communication pipe; the material outlet of the first cyclone is communicated with the inlet of the fresh taro crushing and grinding device; the material outlet of the second cyclone is unidirectionally communicated with the material inlet of the first cyclone; the overflow port of the second cyclone is communicated with a draining device through a communication pipe, and a cyclone pressurizing mechanism is arranged on the communication pipe.
[0007] Further, the cyclone pressurizing mechanism comprises a shell and a spiral rotating shaft rotatably arranged in the shell, the part of the spiral rotating shaft in the shell is spirally wound and the rotating center forms a flow passage, the upper end of the shell is provided with a material inlet pipe, the lower end of the shell is communicated with a material outlet pipe, and the two ends of the flow passage are respectively communicated with the material inlet pipe and the material outlet pipe; the outer ends of the material inlet pipe and the material outlet pipe are respectively communicated with the communication pipe, one end of the spiral rotating shaft penetrates out of the shell, and a driving motor is arranged outside the shell and connected with the one end of the spiral rotating shaft penetrating out of the shell.
[0008] Further, the cyclone pressurizing mechanism is a pressurizing pump or a power pump.
[0009] Further, the draining device comprises a receiving bin, a centrifugal cylinder rotatably arranged in the receiving bin, and a centrifugal motor arranged on the bottom of the receiving bin, the output end of the centrifugal motor is communicated with the rotating center of the centrifugal cylinder, the top of the receiving bin is provided with an opening, the opening is provided with a cover, the cover is buckled on the opening, the cover is provided with a sealing part matched with the top of the centrifugal cylinder, the sealing part is buckled on the top of the centrifugal cylinder to seal the top of the centrifugal cylinder, the cover is provided with a feeding pipe, the outer end of the communication pipe communicated with the overflow port of the second cyclone is connected with the feeding pipe, and the bottom of the receiving bin is provided with a slurry discharge pipe which can be opened and closed.
[0010] Further, the slurry discharge pipe is communicated with a temporary storage tank.
[0011] Further, the inner wall of the one end of the communication pipe is provided with a plurality of spiral flow guide grooves.
[0012] Further, the bottom of the first cyclone and the second cyclone is respectively provided with a normally closed discharge valve.
[0013] Further, the overflow port of the secondary cyclone is further provided with a tertiary cyclone between the overflow port of the secondary cyclone and the draining device, the inlet end of the tertiary cyclone and the overflow port of the secondary cyclone are communicated through a communication pipe, the overflow port of the tertiary cyclone and the draining device are communicated through the communication pipe, the communication pipe between the tertiary cyclone and the secondary cyclone is also provided with a cyclone pressurizing mechanism, and the outlet end of the tertiary cyclone is unidirectionally communicated with the inlet end of the secondary cyclone.
[0014] Further, the receiving bin is provided with a stirring mechanism, and the bottom of the receiving bin is communicated with the inlet end of the primary cyclone through a feeding pipe, and the feeding pipe is provided with a feeding pump.
[0015] Further, the stirring mechanism comprises a stirring motor and a stirring paddle, the stirring motor is installed on the top of the receiving bin, and the stirring paddle is rotatably installed on the receiving bin and connected with the stirring motor.
[0016] Compared with the prior art, the beneficial effects of the present application are as follows:
[0017] The lotus root powder cyclone separation system of the present application is designed to perform sequential cyclone separation through multiple cyclones, thereby improving the particle size of the finally separated lotus root powder particles and ensuring the delicate taste of the lotus root powder in the canned lotus root powder. The lotus root powder slurry with unqualified particle size discharged from the primary cyclone can be returned to the fresh lotus root crushing and grinding equipment for secondary grinding and crushing, thereby ensuring the utilization rate of the product and increasing the production of the product. The unqualified product discharged from the secondary cyclone is returned to the inlet end of the primary cyclone, which realizes secondary recycling, and the relatively large particles can also be discharged from the primary cyclone. The draining device is communicated with the overflow port of the secondary cyclone through a communication pipe, the draining device can be used to control water, which is convenient for subsequent processing. In addition, the cyclone pressurizing mechanism can increase the flow rate of the lotus root powder slurry in the communication pipe, improve the inflow speed of the secondary cyclone, and further ensure the separation effect of the lotus root powder slurry with different particle sizes in the secondary cyclone.
[0018] The present application will be further described in detail below in combination with the drawings and specific embodiments. BRIEF DESCRIPTION OF DRAWINGS
[0019] Figure 1 is a structural schematic view of an embodiment of the present application;
[0020] Figure 2 is a structural schematic view of another embodiment of the present application;
[0021] Figure 3 is an internal structural schematic view of the draining device in the embodiment of the present application;
[0022] Figure 4is a sectional view of the cyclone pressurizing mechanism in the embodiment of the utility model.
[0023] Explanation of reference numerals:
[0024] The fresh lotus root crushing and grinding equipment 10, the receiving bin 20, the supply pipe 21, the supply pump 22, the stirring motor 23, the stirring paddle 24, the primary cyclone 30, the secondary cyclone 40, the communication pipe 50, the spiral flow guide groove 51, the draining device 60, the receiving box 61, the centrifugal cylinder 62, the cover 64, the sealing and pressing part 65, the feeding pipe 66, the slurry discharge pipe 67, the temporary storage tank 68, the cyclone pressurizing mechanism 70, the shell 71, the spiral rotating shaft 72, the feeding pipe 73, the discharging pipe 74, the driving motor 75, the discharge valve 80, and the tertiary cyclone 90. Specific embodiments
[0025] In order to make the purpose, technical scheme and advantages of the utility model clearer and more apparent, the utility model will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the utility model and not to limit the utility model.
[0026] With reference to Figures 1 to 4 The lotus root powder cyclone separation system shown in the drawing is used for particle classification of lotus root powder slurry discharged by the fresh lotus root crushing and grinding equipment 10, and comprises a receiving bin 20, a primary cyclone 30 and a secondary cyclone 40. The receiving bin 20 is used for receiving the lotus root powder slurry discharged by the fresh lotus root crushing and grinding equipment 10. The feeding end of the primary cyclone 30 is in communication with the output end of the receiving bin 20. The overflow port of the primary cyclone 30 is in communication with the feeding end of the secondary cyclone 40 through a communication pipe 50. The discharging end of the primary cyclone 30 is in communication with the inlet end of the fresh lotus root crushing and grinding equipment 10. The discharging end of the secondary cyclone 40 is in one-way communication with the feeding end of the primary cyclone 30. The overflow port of the secondary cyclone 40 is in communication with a draining device 60 through the communication pipe 50, and the communication pipe 50 is provided with a cyclone pressurizing mechanism 70.
[0027] Specifically, in the above embodiment, the main purpose of the draining device 60 is to separate the lotus root powder slurry after cyclone from water, so as to remove the water in the fresh lotus root, facilitate re-brewing of new lotus root powder slurry in the later stage, and ensure gelatinization of the lotus root powder slurry in the later stage and product taste. In addition, the cyclone pressurizing mechanism 70 can adopt a conventional pressurizing pump or a power pump, as long as it is a device capable of accelerating fluid. The fresh lotus root crushing and grinding equipment 10 is a conventional device, which is widely used in the processing and production of lotus root powder, and will not be described in detail herein. The primary cyclone 30 and the secondary cyclone 40 can adopt conventional cyclones in this application, but it needs to be noted that the cyclone needs to realize sealed work, which can reduce the risk of oxidation of the lotus root powder slurry by oxygen in the air during cyclone.
[0028] The design of the present sweet potato flour cyclone separation system is to carry out sequential cyclone separation by multi-stage cyclone, which improves the particle size of the finally separated sweet potato flour particles and ensures the fine taste of the sweet potato flour in the later canned sweet potato. The sweet potato slurry with unqualified particle size discharged from the first cyclone 30 can be returned to the fresh sweet potato crushing and grinding device 10 for secondary grinding and crushing, which ensures the utilization rate of the product and increases the production of the product. The unqualified product discharged from the second cyclone 40 is returned to the inlet end of the first cyclone 30, which realizes secondary recycling, and the larger particles inside can also be discharged from the first cyclone 30. The overflow port of the second cyclone 40 is connected to the draining device 60 through the connecting pipe 50, and the draining device 60 can control water and facilitate subsequent processing. In addition, the cyclone pressurizing mechanism 70 can increase the flow rate of the sweet potato slurry in the connecting pipe 50, improve the inflow speed of the second cyclone 40, and further ensure the separation effect of sweet potato slurry with different particle sizes in the second cyclone 40.
[0029] Referring to Figures 1 to 2 In an embodiment of the present application, in order to facilitate the supply of sweet potato slurry to the first cyclone 30 and the temporary storage of sweet potato slurry discharged from the fresh sweet potato crushing and grinding device 10, a stirring mechanism is arranged in the receiving bin 20. The bottom of the receiving bin 20 is connected to the inlet end of the first cyclone 30 through the supply pipe 21, and the supply pipe 21 is provided with a supply pump 22. The purpose of arranging the stirring mechanism is to avoid the deposition of sweet potato slurry. In order to facilitate discharge, the bottom of the receiving bin 20 is conical. In addition, the stirring mechanism includes a stirring motor 23 and a stirring paddle 24. The stirring motor 23 is installed on the top of the receiving bin 20, and the stirring paddle 24 is rotatably installed on the receiving bin 20 and connected to the stirring motor 23.
[0030] Referring to Figure 2In an embodiment of the present application, in order to improve the particle size of the product after the final cyclone separation, the overflow port of the secondary cyclone 40 is further provided with a tertiary cyclone 90 between the overflow port of the secondary cyclone 40 and the draining device 60. The inlet end of the tertiary cyclone 90 and the overflow port of the secondary cyclone 40 are connected by a communication pipe 50, and the overflow port of the tertiary cyclone 90 and the draining device 60 are also connected by a communication pipe 50. A cyclone pressurizing mechanism 70 is arranged on the communication pipe 50 between the tertiary cyclone 90 and the secondary cyclone 40. The outlet end of the tertiary cyclone 90 is unidirectionally connected to the inlet end of the secondary cyclone 40. In fact, in the normal processing process, the cyclone can be directly used in two stages. The particle sizes of the solid particles in the sago slurry overflowed by the secondary cyclone 40 and the tertiary cyclone 90 are not much different. Therefore, increasing the number of tertiary cyclones 90 will obviously increase the manufacturing cost. Therefore, in the actual processing process, the number of cyclones is selected according to the actual product demand.
[0031] The inlet end of the primary cyclone 20 is connected to the inlet end of the residue-water separation device. This arrangement can make the large sago particles re-enter the residue-water separation device for filtration, and part of the sago slurry can be recycled. The purpose of designing three different cyclones for step-by-step cyclone separation is to ensure that the solid particles in the sago slurry overflowed from the overflow port of the tertiary cyclone meet the particle size requirements. This avoids the traditional need to dry the sago slurry and then perform secondary grinding and rehydration for brewing, simplifies the process, and reduces production costs.
[0032] Referring to Figure 2 and Figure 3In an embodiment of the present application, the water draining device 60 comprises a receiving box 61, a centrifugal cylinder 62 rotatably installed in the receiving box 61, and a centrifugal motor 63 arranged on the bottom of the receiving box 61, the output end of the centrifugal motor 63 being communicated with the rotation center of the centrifugal cylinder 62, the top of the receiving box 61 being provided with an opening, the opening being provided with a cover 64, the cover 64 being buckled on the opening, the cover 64 being provided with a sealing and pressing part 65 matched with the top of the centrifugal cylinder 62, the sealing and pressing part 65 being buckled on the top of the centrifugal cylinder 62 to seal the top of the centrifugal cylinder 62, the cover 64 being provided with a feeding pipe 66, the feeding pipe 66 being connected with the outer end of the communicating pipe 50 communicated with the overflow port of the secondary cyclone 40, the bottom of the receiving box 61 being provided with an openable and closable slurry discharge pipe 67. Wherein, the centrifugal cylinder 62 is actually a cylinder provided with a plurality of water filtering holes on the side wall, and the particle size of the solid particles in the lotus root starch slurry is relatively small, a cloth bag filter screen can be arranged on the inner wall of the centrifugal cylinder 62, the lotus root starch slurry discharged from the feeding pipe is directly discharged into the cloth bag filter screen, such a setting can separate the residue and water by using the cloth bag filter screen, avoiding punching small holes on the centrifugal cylinder 62, and reducing the processing difficulty. At the same time, after the separation is completed, the cloth bag filter screen can be directly taken out, and all the lotus root starch can be taken out, which is simple and convenient.
[0033] In the above embodiment, in order to facilitate the receiving of the slurry waste water discharged from the slurry discharge pipe 67, the slurry discharge pipe 67 is communicated with a temporary storage tank 68.
[0034] Referring to Figure 4In an embodiment of the present application, in order to increase the feeding speed of the next stage cyclone, the particle size specification of the solid particles in the overflowed sago slurry gradually becomes the same after the sago slurry passes through the cyclone separation of each stage cyclone. In order to improve the separation capacity in the later stage, the main function of the cyclone pressurizing mechanism 70 is to facilitate the increase of the inflow speed of the sago slurry flowing into the next stage cyclone through the communication pipe 50. In the centrifugal field formed inside the cyclone, the centrifugal force acting on a mass m is F = mv2 / r; in the formula, m represents the mass of the particle, v represents the tangential velocity, and r represents the radius of rotation. Therefore, under the condition that the inflow speed increases and the other structures of the cyclone are the same, the centrifugal force received by the solid particles with relatively larger particle size is greater, so that the solid particles with close particle size can be separated from the next stage cyclone. Therefore, the cyclone pressurizing mechanism 70 includes a shell 71 and a spiral rotating shaft 72 rotatably installed in the shell 71, the part of the spiral rotating shaft 72 located in the shell 71 is spirally wound and the center of rotation forms a flow passage, the upper end of the shell 71 is provided with a feeding pipe 73, the lower end of the shell 71 is communicated with a discharge pipe 74, and the two ends of the flow passage are respectively communicated with the feeding pipe 73 and the discharge pipe 74; the outer ends of the feeding pipe 73 and the discharge pipe 74 are respectively communicated with the communication pipe 50, one end of the spiral rotating shaft 72 penetrates out of the shell 71, a driving motor 75 is arranged outside the shell 71, and the driving motor 75 is connected with the one end of the spiral rotating shaft 72 penetrating out of the shell 71.
[0035] The spiral rotating shaft 72 is actually designed as a hollow spiral auger, and both ends thereof are provided with concentric shaft structures, so that the spiral rotating shaft 72 can be installed and rotated. The design of the hollow spiral auger can reduce the impact of the sago slurry discharged from the previous stage cyclone on the spiral rotating shaft 72, and the structure of the spiral rotating shaft 72 can also increase the separation capacity to a certain extent. In addition, the shell 71 is in a cylindrical shape, and the feeding pipe 73 and the discharge pipe 74 are tangent to the shell 71, which can minimize the impact on the flow rate of the sago slurry. The feeding pipe 73 and the discharge pipe 74 can be connected with the communication pipe 50 through a joint, or in some embodiments, the feeding pipe 73 and the discharge pipe 74 can be part of the communication pipe 50 and be directly screwed on the shell 71.
[0036] In some embodiments, a plurality of spiral guide grooves 51 are arranged on the inner wall of one end of the communication pipe 50. The spiral guide grooves 51 are arranged to regularize the sago slurry discharged from the communication pipe 50 and reduce the turbulent flow. At the same time, the sago slurry discharged from the communication pipe 50 has a rotating force, and the sago slurry with the rotating force can be better separated by cyclone separation when entering the next stage cyclone, thereby accelerating the efficiency of cyclone separation.
[0037] Further, the bottom of the primary cyclone 30 and the secondary cyclone 40 is provided with a normally closed discharge valve 80, which is to facilitate the outward discharge of the substances that cannot be discharged through the discharge port, and also facilitate the later cleaning of the interior of the cyclone.
[0038] The above-mentioned embodiments are only preferred embodiments of the present application, and cannot be used to limit the scope of protection of the present application, and any non-essential changes and substitutions made by those skilled in the art on the basis of the present application shall fall within the scope of protection of the present application.
Claims
1. A sago cyclone separation system for classifying the particles of sago slurry discharged from a fresh sago crushing and grinding apparatus (10), characterized by, The application relates to a fresh lotus root powder crushing and grinding device, which comprises a receiving bin (20), a primary cyclone (30) and a secondary cyclone (40), the receiving bin (20) is used for receiving lotus root powder slurry discharged by the fresh lotus root powder crushing and grinding device (10), the inlet of the primary cyclone (30) is communicated with the outlet of the receiving bin (20), the overflow port of the primary cyclone (30) is communicated with the inlet of the secondary cyclone (40) through a communicating pipe (50), the outlet of the primary cyclone (30) is communicated with the inlet of the fresh lotus root powder crushing and grinding device (10), the outlet of the secondary cyclone (40) is unidirectionally communicated with the inlet of the primary cyclone (30), and the overflow port of the secondary cyclone (40) is communicated with a draining device (60) through the communicating pipe (50), and a cyclone pressurizing mechanism (70) is arranged on the communicating pipe (50).
2. A sago cyclone separation system as claimed in claim 1, wherein: The cyclone pressurizing mechanism (70) comprises a shell (71) and a spiral rotating shaft (72) rotatably arranged in the shell (71), the spiral rotating shaft (72) is spirally wound in the shell (71) and forms a flow channel at the rotating center, an inlet pipe (73) is arranged at the upper end of the shell (71), a discharge pipe (74) is communicated with the lower end of the shell (71), and the two ends of the flow channel are respectively communicated with the inlet pipe (73) and the discharge pipe (74); the outer ends of the inlet pipe (73) and the discharge pipe (74) are respectively communicated with the communicating pipe (50), one end of the spiral rotating shaft (72) penetrates through the shell (71), a driving motor (75) is arranged outside the shell (71), and the driving motor (75) is connected with the one end of the spiral rotating shaft (72) penetrating through the shell (71).
3. A sago cyclone separation system as claimed in claim 1, wherein: The cyclone pressurizing mechanism (70) is a pressurizing pump or a power pump.
4. A sago cyclone separation system as claimed in claim 1, wherein: The draining device (60) comprises a receiving box (61), a centrifugal cylinder (62) rotatably arranged in the receiving box (61) and a centrifugal motor (63) arranged on the bottom of the receiving box (61), the output end of the centrifugal motor (63) is communicated with the rotating center of the centrifugal cylinder (62), the top of the receiving box (61) is provided with an opening, a cover (64) is arranged on the opening, the cover (64) is buckled on the opening, a sealing and pressing part (65) matched with the top of the centrifugal cylinder (62) is arranged in the cover (64), the sealing and pressing part (65) is buckled on the top of the centrifugal cylinder (62) to seal the top of the centrifugal cylinder (62), a feeding pipe (66) is arranged on the cover (64), the outer end of the feeding pipe (66) is connected with the communicating pipe (50) communicated with the overflow port of the secondary cyclone (40), and the bottom of the receiving box (61) is provided with a slurry discharging pipe (67) capable of being opened and closed.
5. A sago cyclone separation system as claimed in claim 4, wherein: The slurry discharging pipe (67) is communicated with a temporary storage tank (68).
6. A sago cyclone separation system as claimed in claim 1, wherein: A plurality of spiral flow guide grooves (51) are arranged on the inner wall of the liquid outlet end of the communicating pipe (50).
7. A sago cyclone separation system as claimed in claim 1, wherein: The bottom of the primary cyclone (30) and the secondary cyclone (40) is respectively provided with a normally closed discharging valve (80).
8. A sago cyclone separation system as claimed in any one of claims 1 to 7, characterised in that: The overflow of the secondary cyclone (40) is further provided with a tertiary cyclone (90) between the overflow and the draining device (60), the inlet end of the tertiary cyclone (90) and the overflow of the secondary cyclone (40) are communicated through a communicating pipe (50), the overflow of the tertiary cyclone (90) and the draining device (60) are also communicated through the communicating pipe (50), the communicating pipe (50) between the tertiary cyclone (90) and the secondary cyclone (40) is further provided with a cyclone pressurizing mechanism (70), the outlet end of the tertiary cyclone (90) is unidirectionally communicated with the inlet end of the secondary cyclone (40).
9. A sago cyclone separation system as claimed in any one of claims 1 to 7, wherein: The receiving bin (20) is provided with a stirring mechanism, the bottom of the receiving bin (20) is communicated with the inlet end of the primary cyclone (30) through a feeding pipe (21), and the feeding pipe (21) is provided with a feeding pump (22).
10. A sago cyclone separation system as claimed in claim 9, wherein: The stirring mechanism comprises a stirring motor (23) and a stirring paddle (24), the stirring motor (23) is installed on the top of the receiving bin (20), and the stirring paddle (24) is rotatably installed on the receiving bin (20) and connected with the stirring motor (23).