A kind of calcining preparation method of calcined oyster

Abstract

The invention discloses a calcining preparation method for calcined oysters, comprising the following steps: raw material preparation, low-temperature drying, crushing, screening and grading, uniform material distribution, segmented heating, multi-atmosphere calcining, dynamic calcining and gradual cooling. The quality and stability of the calcined oysters are significantly improved through the designed segmented heating and multi-atmosphere calcining. The segmented heating gradually increases the temperature in stages, so that the material undergoes corresponding chemical reactions and physical changes in different temperature sections, thereby avoiding thermal stress and physical damage caused by a sudden temperature rise, improving the calcining effect and product quality. The multi-atmosphere calcining can achieve precise control of the chemical reactions and physical changes in the calcining process, improving the quality of the calcined oysters, reducing impurities, preventing excessive oxidation, and ensuring uniform conversion and stability of minerals. The crushing and screening and grading improve the uniformity of calcining, and prevent uneven calcining due to different particle sizes. The uniform material distribution and dynamic calcining improve the calcining effect, making the product quality more consistent.

Description

Technical Field

[0001] The invention relates to the technical field of calcined oyster preparation, in particular to a calcination preparation method of calcined oyster. Background Art

[0002] Calcined oyster is an important medicine in Chinese herbal medicine, mainly derived from oyster shell. Through the calcination process, the properties of oyster shell will change significantly, making it more suitable for use in Chinese medicine preparations. Calcined oyster is widely used in traditional Chinese medicine for sedation, tranquilization, and astringency, and is often used to treat insomnia, palpitations, night sweats and other symptoms.

[0003] The 2005 edition of the Chinese Pharmacopoeia stipulates that the processing of oysters is as follows: Take clean oysters and calcine them by lighting method until they are crisp. The lighting method is: Take clean oysters and place them on a smokeless stove or in a suitable container and calcine them until they are crisp or red, then take them out, cool them down and crush them;

[0004] The "National Standards for the Preparation of Traditional Chinese Medicine" (1988 edition) stipulates that to calcine oysters, take clean oysters, place them on a smokeless stove or in a suitable container, heat them over high heat, and take them out when they are crispy, let them cool, and crush them.

[0005] Currently, oysters are generally calcined by direct heating. Rapid heating will cause a large temperature difference between the inside and outside of the oyster shell, resulting in great thermal stress. The stress can easily cause the oyster shell to crack, affecting the uniformity and integrity of the finished product and reducing product quality.

[0006] Therefore, we propose a calcination preparation method for calcined oysters. Summary of the invention

[0007] In order to overcome the shortcomings of the prior art, the present invention provides a calcining preparation method for calcined oysters. The quality and stability of the calcined oysters are significantly improved through designed segmented heating and multi-atmosphere calcining. The segmented heating gradually increases the temperature in stages, so that the material undergoes corresponding chemical reactions and physical changes in different temperature sections, which can avoid thermal stress and physical damage caused by sudden temperature rise, improve the calcining effect and product quality, and the multi-atmosphere calcining can achieve precise control of chemical reactions and physical changes during the calcining process, improve the quality of the calcined oysters, reduce impurities, prevent excessive oxidation, and ensure uniform conversion and stability of minerals.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0009] A calcining preparation method for calcined oysters comprises the following steps:

[0010] Raw material preparation: Select complete and clean oyster shells, wash them with clean water, remove mud and attachments, and dry them for later use;

[0011] Low-temperature drying: Place the cleaned oyster shells in a drying oven, set the temperature to 60-80°C, and dry for 3-4 hours;

[0012] Crushing: Put the dried oyster shells into a crusher for crushing;

[0013] Screening and grading: Use a vibrating screen or a rotary screen to screen the crushed oyster shells and classify oyster shells of different particle sizes into different grades;

[0014] Even distribution: the oyster shell particles after screening and classification are spread in the forging pot, and the thickness of the oyster shell particles is uniform;

[0015] Segmented heating: The smelting process of oyster shells in the forging pot is divided into three stages:

[0016] The initial stage is calcined for 1-2 hours at a temperature of 0-300°C;

[0017] The intermediate stage is calcined for 3-4 hours at a temperature of 300-600°C;

[0018] The later stage is calcined for 2-4 hours at a temperature of 600-1000°C;

[0019] Multi-atmosphere calcining: different proportions of gases are introduced into the calcining pot at different calcining stages, including nitrogen, oxygen, argon and carbon dioxide;

[0020] Dynamic calcination: The oyster shells are turned over regularly while being calcined in the calcination pot, with a frequency of 5 times per hour;

[0021] Gradually cool down: the temperature of the forging pot is gradually lowered at a rate of 100°C per hour. After the temperature drops to room temperature, the operation of the forging pot is stopped. The calcined oyster shells are taken out of the forging pot and placed in a dry and ventilated place for natural cooling.

[0022] As a preferred embodiment of the calcination preparation method of the calcined oyster described in the present invention, the oyster shells are cleaned by ultrasonic cleaning equipment: the oyster shells are placed in a cleaning pool, injected with clean water or warm water and soaked for 30 minutes, the ultrasonic cleaning equipment is started, the frequency is set to 40-50kHz, and the cleaning is carried out for 20-30 minutes.

[0023] As a preferred embodiment of the calcined preparation method of the calcined oyster of the present invention, the pulverization is performed using a jaw crusher, the dried oyster shells are placed in the jaw crusher, the rotation speed is set to 400-500rpm, and the oyster shells are pulverized into particles with a diameter of 2-5 mm.

[0024] As a preferred embodiment of the calcining preparation method of the calcined oyster described in the present invention, the vibrating screen or rotary screen for screening and grading is installed with screens of different apertures ranging from 2 to 5 mm, so as to remove oyster shell particles that are not in the range of 2 to 5 mm.

[0025] As a preferred embodiment of the calcination preparation method of the calcined oyster described in the present invention, the initial stage of segmented heating is to gradually heat at a rate of 100°C per hour, the calcination time is 2 hours, and the temperature is maintained constant for 30 minutes after reaching 200°C.

[0026] As a preferred embodiment of the calcination preparation method of the calcined oyster described in the present invention, the intermediate stage of the segmented heating is as follows: the initial calcination temperature is 200°C, and the temperature is gradually heated at a rate of 100°C per hour. The calcination time is 4 hours, and the temperature is maintained constant for 1 hour after reaching 600°C.

[0027] As a preferred embodiment of the calcination preparation method of the calcined oyster described in the present invention, in the later stage of segmented heating, the initial calcination temperature is 600°C, and the temperature is gradually heated at a rate of 100°C per hour. The calcination time is 4 hours, and the temperature is maintained constant for 2 hours after reaching 1000°C.

[0028] As a preferred embodiment of the calcination preparation method of the calcined oyster described in the present invention, the multi-atmosphere calcination is carried out in the initial stage of the calcination pot, and the gases introduced include nitrogen and oxygen, and the composition ratio is 80% nitrogen and 20% oxygen.

[0029] As a preferred embodiment of the calcination preparation method of the calcined oyster described in the present invention, the multi-atmosphere calcination is carried out in the middle stage of the calcination pot, and the gases introduced include nitrogen, oxygen and argon, and the composition ratio is 60% nitrogen, 20% oxygen and 20% argon.

[0030] As a preferred embodiment of the calcination preparation method of the calcined oyster described in the present invention, the calcination is carried out in a medium-multi-atmosphere in the later stage of the calcination pot, and the gases introduced include carbon dioxide and nitrogen, with a composition ratio of 70% nitrogen and 30% carbon dioxide.

[0031] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0032] The quality and stability of calcined oysters are significantly improved through the designed segmented heating and multi-atmosphere calcining. The segmented heating gradually increases the temperature in stages, so that the material undergoes corresponding chemical reactions and physical changes in different temperature ranges, which can avoid the thermal stress and physical damage caused by sudden temperature rise, improve the calcining effect and product quality. Multi-atmosphere calcining can achieve precise control of chemical reactions and physical changes during the calcining process, improve the quality of calcined oysters, reduce impurities, prevent excessive oxidation, and ensure uniform conversion and stability of minerals. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The present invention is a flowchart of a method for preparing calcined oysters by calcining. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0035] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0036] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0037] Example

[0038] Please refer to Figure 1 As shown, this embodiment provides a method for preparing calcined oysters, comprising the following steps:

[0039] Step 1: Raw material preparation: Select complete and clean oyster shells, wash them with clean water, remove mud and attachments, dry them for later use, and make sure the surface of the oyster shells is clean and free of obvious impurities;

[0040] Among them, the oyster shells are cleaned by ultrasonic cleaning equipment: the oyster shells are placed in a cleaning pool, injected with clean water or warm water to soak for 30 minutes, the ultrasonic cleaning equipment is started, the frequency is set to 40-50kHz, and the cleaning is carried out for 20-30 minutes. After cleaning, the oyster shells are taken out, the water is drained, and the impurities and organic matter on the surface of the oyster shells are removed to improve the calcining effect;

[0041] Ultrasonic cleaning can completely remove the sand and organic matter on the surface of the oyster shell, improve the purity of the calcination process, ensure the purity of the calcined product, and reduce the impact of impurities;

[0042] Step 2, low-temperature drying: put the cleaned oyster shells into a drying oven, set the temperature to 60-80℃, and dry for 3-4 hours until the oyster shells are completely dry. Low-temperature drying prevents over-drying from causing shell cracking, removes moisture from the oyster shells, prepares for calcining, and prevents cracks or bursts caused by residual moisture during the calcining process;

[0043] Step 3, crushing: put the dried oyster shells into a crusher for crushing. The crushing adopts a jaw crusher. Put the dried oyster shells into the jaw crusher, set the speed to 400-500rpm, and crush them into particles with a diameter of 2-5 mm. Control the particle size to ensure uniform heating during calcination. The oyster shells are crushed into particles to increase the heating area during calcination.

[0044] Step 4: Screening and grading: Use a vibrating screen or a rotary screen to screen the crushed oyster shells, and classify oyster shells of different particle sizes into different grades to ensure that the particle size is uniform and the heat is uniform during the calcining process, and to prevent uneven calcination due to different particle sizes;

[0045] Among them, the vibrating screen or rotary screen is installed with screens of different apertures ranging from 2 to 5 mm, which is used to remove oyster shell particles that are not in the range of 2 to 5 mm, that is, to remove particles that are too large or too small, to ensure that the particle size is uniform and the heating is uniform during the calcining process;

[0046] Step 5: Evenly distribute the material: the screened and graded oyster shell particles are spread in the forging pot. The thickness of the oyster shell particles is uniform, ensuring that the oyster shells are evenly heated during the forging process, avoiding local overheating, improving the forging effect, and making the product quality more consistent;

[0047] Step 6: Segmented heating: The smelting process of oyster shells in the forging pot is divided into three stages:

[0048] The initial stage is calcined for 1-2 hours at a temperature of 0-300°C to remove residual moisture;

[0049] The intermediate stage is calcined for 3-4 hours at a temperature of 300-600°C to decompose organic matter;

[0050] The late stage is calcined for 2-4 hours at a temperature of 600-1000°C to complete the high temperature treatment;

[0051] By heating in stages, water and organic matter are gradually removed, the calcination effect is improved, damage caused by high temperature at one time is avoided, production efficiency is improved, and consistent product quality is ensured;

[0052] Specifically, in the initial stage: gradually heat at a rate of 100°C per hour for 2 hours, and keep the temperature constant for 30 minutes after reaching 200°C to remove free moisture in the oyster shell, prevent the shell from bursting, and improve the stability of the calcination process;

[0053] Intermediate stage: The initial calcination temperature is 200°C, and the temperature is gradually heated at a rate of 100°C per hour for 4 hours. After reaching 600°C, the temperature is kept constant for 1 hour to remove bound water and organic matter, gradually decompose inorganic salts, and reduce smoke and pollution during the calcination process;

[0054] Later stage: the initial calcination temperature is 600℃, and the temperature is gradually increased at a rate of 100℃ per hour for 4 hours. After reaching 1000℃, the temperature is kept constant for 2 hours to achieve complete calcination and transformation of minerals, form stable calcined oysters, and improve product quality;

[0055] Step 7, multi-atmosphere calcining: different proportions of gases are introduced into the calcining pot at different calcining stages. The gases include nitrogen, oxygen, argon and carbon dioxide. The atmosphere composition in the calcining pot is controlled to prevent adverse chemical reactions. The calcining effect is precisely controlled by changing the composition and proportion of the atmosphere during the calcining process to ensure the high quality of the calcined oysters.

[0056] Specifically, in the initial stage of multi-atmosphere forging in the forging pot, the gases introduced include nitrogen and oxygen, with a composition ratio of 80% nitrogen and 20% oxygen. The nitrogen and oxygen are continuously heated in this stage to gradually remove moisture and organic matter in the oyster shells.

[0057] In the middle stage of multi-atmosphere forging in the forging pot, the gases introduced include nitrogen, oxygen and argon, with a composition ratio of 60% nitrogen, 20% oxygen and 20% argon. In this stage, nitrogen, oxygen and argon control the mineral conversion rate and ensure uniform reaction;

[0058] Multi-atmosphere forging is carried out in the later stage of the forging pot. The gases introduced include carbon dioxide and nitrogen, with a composition ratio of 70% nitrogen and 30% carbon dioxide. At this stage, carbon dioxide and nitrogen stabilize the mineral structure, reduce oxidation reactions, and ensure product quality.

[0059] Through multi-atmosphere calcination, the chemical reactions and physical changes during the calcination process are precisely controlled to improve the quality of calcined oysters, reduce impurities, prevent excessive oxidation, ensure uniform conversion and stability of minerals, and improve the consistency and stability of the product, meeting the high quality standards of medicinal materials;

[0060] Step 8: Dynamic calcination: The oyster shells are turned over regularly while being calcined in the calcination pot, with a frequency of 5 times per hour. Through dynamic turning, the oyster shells are heated evenly to avoid local overheating or overcooling.

[0061] Step 9. Gradually cool down: The temperature of the forging pot is gradually lowered at a rate of 100°C per hour. After the temperature drops to room temperature, the operation of the forging pot is stopped. The calcined oyster shells are taken out of the forging pot and placed in a dry and ventilated place for natural cooling to avoid cracks in the shell caused by a sudden drop in temperature.

[0062] The quality and stability of calcined oysters are significantly improved through the designed segmented heating and multi-atmosphere calcining. The segmented heating gradually increases the temperature in stages, so that the material undergoes corresponding chemical reactions and physical changes in different temperature ranges, which can avoid the thermal stress and physical damage caused by sudden temperature rise, improve the calcining effect and product quality. Multi-atmosphere calcining can achieve precise control of chemical reactions and physical changes during the calcining process, improve the quality of calcined oysters, reduce impurities, prevent excessive oxidation, and ensure uniform conversion and stability of minerals.

[0063] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for preparing calcined oysters, characterized in that: The steps include: S1. Raw material preparation: select complete and clean oyster shells, wash them with clean water, remove mud and attachments, and dry them for later use; S2, low temperature drying: put the cleaned oyster shells into a drying oven, set the temperature to 60-80°C, and dry for 3-4 hours; S3, crushing: putting the dried oyster shells into a crusher for crushing; S4. Screening and grading: Use a vibrating screen or a rotary screen to screen the crushed oyster shells, and classify oyster shells of different particle sizes into different grades; S5. Uniform distribution: the screened and graded oyster shell particles are spread in the forging pot, and the thickness of the oyster shell particles is uniform; S6, segmented heating: the smelting process of oyster shells in the forging pot is divided into three stages: The initial stage is calcined for 1-2 hours at a temperature of 0-300°C; The intermediate stage is calcined for 3-4 hours at a temperature of 300-600°C; The later stage is calcined for 2-4 hours at a temperature of 600-1000°C; S7, multi-atmosphere calcining: different proportions of gases are introduced into the calcining pot at different calcining stages, and the gases include nitrogen, oxygen, argon and carbon dioxide; S8, dynamic calcination: the oyster shells are regularly turned over in the calcination pot, with a frequency of 5 times per hour; S9. Gradually cool down: the temperature of the forging pot is gradually lowered at a rate of 100°C per hour. After the temperature drops to room temperature, the operation of the forging pot is stopped. The calcined oyster shells are taken out of the forging pot and placed in a dry and ventilated place for natural cooling.

2. The method for preparing calcined oyster according to claim 1, characterized in that: The oyster shells cleaned in S1 are cleaned by ultrasonic cleaning equipment: the oyster shells are placed in a cleaning tank, filled with clean water or warm water and soaked for 30 minutes, the ultrasonic cleaning equipment is started, the frequency is set to 40-50kHz, and the cleaning is carried out for 20-30 minutes.

3. The method for preparing calcined oyster according to claim 1, characterized in that: In S3, the pulverizing is performed using a jaw crusher. The dried oyster shells are placed in the jaw crusher, the rotation speed is set to 400-500 rpm, and the oyster shells are pulverized into particles with a diameter of 2-5 mm.

4. The method for preparing calcined oyster according to claim 1, characterized in that: The vibrating screen or rotary screen used for screening and grading in S4 is installed with screens of different apertures ranging from 2 to 5 mm, so as to remove oyster shell particles that are not within the range of 2 to 5 mm.

5. The method for preparing calcined oyster according to claim 1, characterized in that: The initial stage of the segmented heating in S6 is: gradually heating at a rate of 100° C. per hour, the calcination time is 2 hours, and the temperature is kept constant for 30 minutes after reaching 200° C.

6. The method for preparing calcined oyster according to claim 1, characterized in that: The intermediate stage of the segmented heating in S6 is as follows: the initial calcination temperature is 200° C., and the temperature is gradually heated at a rate of 100° C. per hour for 4 hours. After reaching 600° C., the temperature is kept constant for 1 hour.

7. The method for preparing calcined oyster according to claim 1, characterized in that: In the later stage of the segmented heating in S6, the initial calcination temperature is 600°C, and the temperature is gradually increased at a rate of 100°C per hour for 4 hours. After reaching 1000°C, the temperature is kept constant for 2 hours.

8. The method for preparing calcined oyster according to claim 1, characterized in that: In the multi-atmosphere forging in S7, the gases introduced into the forging pot include nitrogen and oxygen, and the composition ratio is 80% nitrogen and 20% oxygen.

9. The method for preparing calcined oyster according to claim 1, characterized in that: In the S7, the multi-atmosphere forging is carried out in the middle stage of the forging pot, and the gases introduced include nitrogen, oxygen and argon, and the composition ratio is 60% nitrogen, 20% oxygen and 20% argon.

10. The method for preparing calcined oyster according to claim 1, characterized in that: In the S7, the multi-atmosphere forging is carried out in the later stage of the forging pot, and the gases introduced include carbon dioxide and nitrogen, with the composition ratio being 70% nitrogen and 30% carbon dioxide.

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