A wet cold grinding high tds coffee liquid, preparation system and application method

Abstract

The present application relates to the technical field of instant coffee preparation, and in particular to a wet cold grinding high-TDS coffee liquid, a preparation system and an application method. The coffee liquid is prepared by the application method using the preparation system. The preparation system comprises a first grinding system, a second grinding system and a controller connected with the two grinding systems; the controller is used to control the combined grinding of the first grinding system and the second grinding system, and the TDS of the coffee liquid after grinding can reach 12% to 15%. The application method can not only prepare coffee liquid products with high TDS content and high extraction rate, but also solve the problem of heavy bitterness of the extracted coffee caused by the existing hot quenching method.

Description

Technical Field

[0001] This invention relates to the field of instant coffee preparation technology, and in particular to a wet-process cold-ground high TDS coffee liquid, preparation system and application method. Background Technology

[0002] Coffee is divided into freshly ground coffee and instant coffee, with a market share of approximately 30% to 70%. Currently, the production process of instant coffee is generally as follows: coffee beans are screened, washed, and roasted, then ground in a roller mill to obtain a relatively large powder, with a fineness of 200-800μm. After grinding, the coffee aroma is fully released, and the factory needs to collect and process this "aroma." Next, the ground coffee powder needs to be extracted into coffee liquid. Common extraction methods are divided into hot extraction and cold extraction. Hot extraction is further divided into atmospheric pressure hot extraction and high-pressure hot extraction.

[0003] Atmospheric pressure hot extraction: Ground coffee powder is mixed with hot water for extraction. The temperature of the hot water is usually controlled between 85 and 95°C, with a total material-to-liquid ratio of 1:4 to 1:16, and the total dissolved solids (TDS) of the coffee liquid is 1.0% to 6.0%. High-temperature heat extraction not only accelerates the dissolution of substances in the coffee powder, completing the extraction in a short time (approximately 10 to 40 minutes), but also fully extracts coffee oils and aromatic compounds, resulting in a rich coffee liquid with a pronounced caramel aroma. However, the high-temperature environment of heat extraction can easily bring out tannins in the coffee beans, producing a bitter taste. Furthermore, heat extraction requires high-quality coffee beans; defective beans will have their undesirable flavors amplified at high temperatures. Due to the large amount of water used in the extraction, in most cases, the final product needs to be concentrated to a coffee liquid with a TDS greater than 10%, requiring the removal of 50% to 85% of the water; or dried to a coffee powder with a moisture content of 3% to 5%, requiring the removal of 92% to 98% of the water. Concentration or drying is very costly. In addition, the extraction rate of coffee beans produced by the hot extraction method in industry is generally 20% to 25%.

[0004] High-pressure hot extraction: Ground coffee powder is mixed with hot water and extracted in multiple stages or countercurrently. The water temperature is typically controlled between 85 and 195°C, and the pressure between 5 and 20 bar. The total material-to-liquid ratio is 1:4 to 1:6, and the total dissolved solids (TDS) of the coffee liquid is 6.0% to 12.0%. High-temperature, high-pressure extraction accelerates the dissolution of substances in the coffee powder, completing the extraction in a shorter time (approximately 10 to 40 minutes). The TDS of the coffee liquid reaches 6.0% to 12.0%, fully extracting coffee oils and aromatic compounds, resulting in a rich coffee liquid with a pronounced caramel aroma. However, the high pressure and extremely high temperature environment of high-pressure hot extraction can easily damage the flavor of the coffee, making it unsuitable for low- or medium-temperature roasted coffee beans. It is commonly used only for dark and hot-roasted coffee beans. Furthermore, high-pressure hot extraction requires sophisticated equipment; the extraction equipment, containers, and automatic valve assemblies must all be pressure- and heat-resistant, resulting in a high investment in equipment.

[0005] Cold brew: This method uses ice water (4-6℃), room temperature water (20-25℃), or warm water (35-45℃) to extract from ground coffee. The low temperature environment inhibits the precipitation of acidic substances and slows down the release of caffeine. The resulting coffee has low acidity, a crisp and smooth taste, and only one-third the bitterness of hot brew. Because it doesn't undergo high-temperature oxidation, cold brew coffee better preserves the floral and fruity aromas of the coffee beans. However, the cold brew method requires 5-8 hours of contact between the coffee grounds and water to complete extraction, resulting in long processing times and low production efficiency. Furthermore, the liquid-to-powder ratio in cold brew is 1:4 to 1:16. Due to the large amount of water used in extraction, in most cases, the final product needs to be concentrated to a TDS greater than 10%, requiring the removal of 50%-85% of the water; or freeze-dried to a moisture content of 3%-5%, requiring the removal of 92%-98% of the water. Concentration or freeze-drying are very costly. In addition, the extraction rate of cold brew coffee beans in industrial production is generally 15% to 20%.

[0006] Therefore, it is necessary to provide a wet cold-grinding high TDS coffee liquid, preparation system and application method to solve the problem of bitterness in coffee extracted by the existing hot quenching method, the problem of long extraction time and low extraction rate in the existing cold quenching method, and the problem of high concentration or drying costs that exist in both the existing hot quenching and cold quenching methods. Summary of the Invention

[0007] The purpose of this invention is to provide a wet-process cold-ground high TDS coffee liquid, a preparation system, and an application method. The specific technical solution is as follows: In a first aspect, the present invention provides a wet cold-grinding high TDS coffee liquid preparation system, which includes a primary grinding system, a secondary grinding system and a controller; The secondary grinding system includes a second negative pressure bean suction assembly, a second metering component, a second feeding crushing and grinding assembly, a second extraction assembly, a third sedimentation separator, a second mixing tank, a second water supply assembly, a disc centrifuge, and a coffee liquid supply assembly. The second negative pressure bean suction assembly includes a second bean suction end and a second bean supply end; the second bean suction end is connected to a storage tank containing coffee beans; the second bean supply end is connected to the feed end of the second metering component; the discharge end of the second metering component is connected to the feed end of the second feeding crushing and grinding assembly; the discharge end of the second feeding crushing and grinding assembly is connected to the feed end of the second extraction assembly via a first pipeline; the discharge end of the second extraction assembly is connected to the feed end of the third sedimentation separator via a second pipeline; the liquid outlet end of the third sedimentation separator is connected to the disc separator via a third pipeline. The inlet of the centrifuge is connected; the outlet of the disc centrifuge is used to produce coffee liquid; the slag outlet of the third sedimentation separator is connected to the inlet of the second mixing tank; the second water supply assembly is connected to the inlet of the second mixing tank through a fourth pipeline; the outlet of the second mixing tank is used to output the second slurry, and is connected to the second slurry recovery end of the primary grinding system through a fifth pipeline; the outlet of the coffee liquid supply assembly is connected to the feeding crushing and grinding assembly through a sixth pipeline, and its inlet is connected to the coffee liquid output end of the primary grinding system through a seventh pipeline; A first pump is installed on the first pipeline; a second pump is installed on the second pipeline; a third pump is installed on the third pipeline; a fourth pump is installed on the fourth pipeline; a fifth pump is installed on the fifth pipeline; a sixth pump is installed on the sixth pipeline; and a seventh pump is installed on the seventh pipeline. The first pump to the seventh pump, the second negative pressure bean suction assembly, the second metering component, the second feeding crushing and grinding assembly, the second extraction assembly, the third sedimentation separator, the disc centrifuge, the second mixing tank, the second water supply assembly, the coffee liquid supply assembly, and the primary grinding system are all connected to the controller; Automatic regulating valves and flow meters connected to the controller are installed on both the fourth and sixth pipelines. Automatic regulating valves connected to the controller are installed on the first pipeline, the second pipeline, the third pipeline, the fifth pipeline, and the seventh pipeline.

[0008] Optionally, the second negative pressure bean suction assembly includes a second negative pressure pump, a second negative pressure tank, a second bottom valve, a second bean storage tank, and a second weighing sensor; the second negative pressure pump is connected to the second negative pressure tank, and the second negative pressure pump is equipped with a second bypass valve; the second bypass valve is connected to the controller; the second negative pressure tank is connected to a storage tank containing coffee beans through a second vacuum tube; the second bean suction end is disposed on the second vacuum tube; the second bean storage tank is disposed at the bottom outlet of the second negative pressure tank; the second bottom valve is openable and closable at the bottom outlet of the second negative pressure tank; the second bean storage tank is disposed on a second frame; the second weighing sensor is disposed between the second bean storage tank and the second frame; the second bean supply end is disposed at the bottom outlet of the second bean storage tank; the second negative pressure pump, the second bottom valve, and the second weighing sensor are all connected to the controller; The outlet of the coffee liquid supply component is connected to the second negative pressure tank through the eighth pipeline; the outlet of the coffee liquid supply component is connected to the second bean storage tank through the ninth pipeline; the eighth pipeline and the ninth pipeline are both arranged in parallel on the sixth pipeline; an automatic regulating valve connected to the controller is provided on both the eighth pipeline and the ninth pipeline.

[0009] Optionally, the second metering component includes a second metering screw; the feed end of the second metering screw is connected to the second bean supply end; the discharge end of the second metering screw is connected to the second hopper of the second feeding crushing and grinding assembly; the second metering screw is connected to the controller; the second metering screw is a frequency conversion metering screw. The second feeding crushing and grinding assembly includes a second crushing and grinding mill, a second hopper, and a second feeding screw; the discharge end of the second hopper is set to correspond to the feed end of the second feeding screw; the discharge end of the second feeding screw is set to correspond to the feed inlet of the second crushing and grinding mill; both the second crushing and grinding mill and the second feeding screw are connected to the controller; The outlet of the coffee liquid supply component is connected to the second metering spiral through the tenth pipeline; the tenth pipeline is arranged in parallel on the sixth pipeline; an automatic regulating valve connected to the controller is arranged on the tenth pipeline; The outlet of the coffee liquid supply component is connected to the second hopper in the second feeding crushing and grinding component through the sixth pipeline.

[0010] Optionally, the second extraction assembly includes two second extraction tanks connected in parallel on the first pipeline, and each second extraction tank is connected to the controller; the feed end of each second extraction tank is connected in parallel to the first pipeline through a first branch, and an automatic regulating valve connected to the controller is provided on each first branch; the discharge end of each second extraction tank is connected in parallel to the second pipeline through a second branch, and an automatic regulating valve connected to the controller is provided on each second branch. The coffee liquid supply assembly includes a coffee liquid tank, the sixth pipeline, and the sixth pump disposed on the sixth pipeline; the sixth pipeline is disposed at the outlet end of the coffee liquid tank; The second water supply assembly includes a second water storage tank, the fourth pipeline, and the fourth pump installed on the fourth pipeline; one end of the fourth pipeline is connected to the outlet of the second water storage tank, and the other end is connected to the inlet of the second mixing tank. The third sedimentation separator is a third horizontal spiral sedimentation centrifuge.

[0011] Optionally, the primary grinding system includes a first negative pressure bean suction assembly, a first metering component, a first feeding crushing and grinding assembly, a first extraction assembly, a first sedimentation separator, a first mixing tank, a first water supply assembly, a second sedimentation separator, and a second slurry supply assembly. The first negative pressure bean suction assembly includes a first bean suction end and a first bean supply end; the first bean suction end is connected to a storage tank containing coffee beans; the first bean supply end is connected to the feed end of the first metering component; the discharge end of the first metering component is connected to the feed end of the first feeding crushing and grinding assembly; the discharge end of the first feeding crushing and grinding assembly is connected to the feed end of the first extraction assembly via a first pipeline; the discharge end of the first extraction assembly is connected to the feed end of the first sedimentation separator via a second pipeline; the liquid outlet of the first sedimentation separator is the coffee liquid output end of the primary grinding system, which is connected to the liquid inlet of the coffee liquid tank via a seventh pipeline. The first settling separator's slag outlet is connected to the first mixing tank's inlet; the first water supply component is connected to the first mixing tank's inlet via pipe number three; the first mixing tank's outlet is used to output the second slurry and is connected to the second settling separator's inlet via pipe number four; the second settling separator's inlet is the second slurry recovery end in the primary grinding system; the second settling separator's liquid outlet is connected to the second slurry supply component's inlet via pipe number five, while its slag outlet is used to discharge coffee grounds; the second slurry supply component's liquid outlet is connected to the first feeding crushing and grinding component via pipe number six. Pump No. 1 is installed on pipeline No. 1; pump No. 2 is installed on pipeline No. 2; pump No. 3 is installed on pipeline No. 3; pump No. 4 is installed on pipeline No. 4; pump No. 5 is installed on pipeline No. 5; pump No. 6 is installed on pipeline No. 6. Pumps No. 1 through No. 6, the first negative pressure bean suction assembly, the first metering component, the first feeding crushing and grinding assembly, the first extraction assembly, the first sedimentation separator, the second sedimentation separator, the first mixing tank, the first water supply assembly, and the second slurry supply assembly are all connected to the controller. Automatic regulating valves and flow meters connected to the controller are installed on both pipeline No. 3 and pipeline No. 6. Automatic regulating valves connected to the controller are installed on pipelines No. 1, No. 2, No. 4 and No. 5.

[0012] Optionally, the first negative pressure bean suction assembly includes a first negative pressure pump, a first negative pressure tank, a first bottom valve, a first bean storage tank, and a first weighing sensor; the first negative pressure pump is connected to the first negative pressure tank, and the first negative pressure pump is equipped with a first bypass valve; the first bypass valve is connected to the controller; the first negative pressure tank is connected to a storage tank containing coffee beans through a first vacuum tube; the first bean suction end is disposed on the first vacuum tube; the first bean storage tank is disposed at the bottom outlet of the first negative pressure tank; the first bottom valve is openable and closable at the bottom outlet of the first negative pressure tank; the first bean storage tank is disposed on a first frame; the first weighing sensor is disposed between the first bean storage tank and the first frame; the first bean supply end is disposed at the bottom outlet of the first bean storage tank; the first negative pressure pump, the first bottom valve, and the first weighing sensor are all connected to the controller; The outlet of the second slurry supply component is connected to the first negative pressure tank via pipeline No. 7; the outlet of the second slurry supply component is connected to the first soybean storage tank via pipeline No. 8; pipeline No. 7 and pipeline No. 8 are both connected in parallel to pipeline No. 6; automatic regulating valves connected to the controller are installed on both pipeline No. 7 and pipeline No. 8.

[0013] Optionally, the first metering component includes a first metering screw; the feed end of the first metering screw is connected to the first bean supply end; the discharge end of the first metering screw is connected to the first hopper of the first feeding crushing and grinding assembly; the first metering screw is connected to the controller; the first metering screw is a frequency conversion metering screw. The first feeding crushing and grinding assembly includes a first crushing and grinding mill, a first hopper, and a first feeding screw; the discharge end of the first hopper is set to correspond to the feed end of the first feeding screw; the discharge end of the first feeding screw is set to correspond to the feed inlet of the first crushing and grinding mill; the first feeding screw is connected to the controller; The outlet end of the second slurry supply component is connected to the first metering screw via pipeline number nine; pipeline number nine is connected in parallel to pipeline number six; an automatic regulating valve connected to the controller is installed on pipeline number nine. The outlet of the second slurry supply component is connected to the first hopper in the first feeding crushing and grinding component through the sixth pipeline.

[0014] Optionally, the first extraction assembly includes two first extraction tanks connected in parallel on the first pipeline, and each first extraction tank is connected to the controller; the feed end of each first extraction tank is connected in parallel to the first pipeline through a first branch, and an automatic regulating valve connected to the controller is provided on each first branch; the discharge end of each first extraction tank is connected in parallel to the second pipeline through a second branch, and an automatic regulating valve connected to the controller is provided on each second branch. The second slurry supply assembly includes a second slurry tank, the sixth pipeline, and the sixth pump installed on the sixth pipeline; the sixth pipeline is located at the outlet end of the second slurry tank. The first water supply component includes a first water storage tank, the third pipeline, and the third pump installed on the third pipeline; one end of the third pipeline is connected to the outlet of the first water storage tank, and the other end is connected to the inlet of the first mixing tank. The first sedimentation separator is a first horizontal spiral sedimentation centrifuge; The second sedimentation separator is a second horizontal spiral sedimentation centrifuge.

[0015] In a second aspect, the present invention provides a method for applying the aforementioned wet cold-grinding high TDS coffee liquid preparation system, which includes an application method for initial operation and an application method for long-term operation: The application method of the initial task includes: Step S1: The controller starts the first negative pressure pump to create a vacuum in the first negative pressure tank, and controls the first bottom valve to close at the bottom outlet of the first negative pressure tank. Coffee beans are drawn into the first negative pressure tank through the first vacuum tube until the weight of the coffee beans in the first negative pressure tank is greater than the opening pressure of the first bottom valve. Then the controller controls the first bottom valve to open, and the coffee beans fall into the first bean storage tank. The first weighing sensor monitors the weight of coffee beans in the first bean storage tank in real time and transmits the data to the controller. When the weight reaches the upper limit of the preset weight value of the controller, the controller opens the first bypass valve and the first negative pressure pump stops sucking beans. When the weight reaches the lower limit of the preset weight value of the controller, the controller closes the first bypass valve and the first negative pressure pump continues to suck beans. Step S2: Using the controller, open the bottom outlet of the first bean storage tank, the first metering screw, the first feeding screw, and the first crusher / grinder, and control the grinding gap of the first crusher / grinder to be 10~50μm to grind the coffee beans; during the grinding of the coffee beans, use the controller to open the sixth pump, the automatic regulating valve, and the flow meter on the sixth pipeline to provide the second slurry at 5~60℃ for the coffee bean grinding operation, and control the ratio of coffee beans to the second slurry to be 1:3~1:5 to facilitate grinding to obtain a first-grade coffee slurry with a TDS of 6%~8%; the output of the first-grade coffee slurry is 1~10 tons / hour; Step S3: Use the controller to turn on the first pump on the first pipeline and each of the first extraction tanks to complete the extraction of the first-stage coffee slurry; wherein, the controller controls the parallel first extraction tanks to alternately feed and discharge; the controller controls the extraction time of each first extraction tank to be 10~30 minutes. Step S4: Using the controller, turn on the second pump on the second pipeline and the first sedimentation separator to complete the first sedimentation separation operation of the extracted primary coffee slurry and separate the coffee liquid; use the controller to turn on the automatic regulating valve on the seventh pipeline to introduce the coffee liquid into the coffee liquid tank; Coffee grounds discharged from the first sedimentation separator flow into the first mixing tank. The controller is used to turn on the third pump, the automatic regulating valve and the flow meter on the third pipeline to provide clean water at 5~60℃ for coffee grounds extraction, and the ratio of coffee grounds to clean water is controlled to be 1:1.5~1:3. After extraction, a second slurry containing grounds is obtained. The controller is used to turn on the No. 4 pump and the second sedimentation separator to perform a second sedimentation separation operation on the slag-containing slurry, resulting in a liquid-slag separated slurry; the controller is also used to turn on the No. 5 pump to introduce the separated slurry into the slurry tank. Step S5: The controller starts the second negative pressure pump to create a vacuum in the second negative pressure tank, and controls the second bottom valve to close at the bottom outlet of the second negative pressure tank. Coffee beans are drawn into the second negative pressure tank through the second vacuum tube until the weight of the coffee beans in the second negative pressure tank is greater than the opening pressure of the second bottom valve. Then the controller controls the second bottom valve to open, and the coffee beans fall into the second bean storage tank. The second weighing sensor monitors the weight of coffee beans in the second bean storage tank in real time and transmits the data to the controller. When the weight reaches the upper limit of the preset weight value of the controller, the controller opens the second bypass valve and the second negative pressure pump stops sucking beans. When the weight reaches the lower limit of the preset weight value of the controller, the controller closes the second bypass valve and the second negative pressure pump continues to suck beans. The controller opens the bottom outlet of the second bean storage tank, the second metering screw, the second feeding screw, and the second crusher / grinder, and controls the grinding gap of the second crusher / grinder to be 10-50 μm to grind the coffee beans. During grinding, the controller opens the sixth pump, automatic regulating valve, and flow meter on the sixth pipeline to provide coffee liquid at 5-60°C, and controls the ratio of coffee beans to coffee liquid to be 1:3-1:5 to facilitate grinding and obtaining a secondary coffee slurry with a TDS of 12%-15%. The output of the secondary coffee slurry is 1-10 tons / hour. Step S6: Using the controller, open the first pump on the first pipeline and each of the second extraction tanks to complete the extraction of the secondary coffee slurry; wherein, the controller controls the parallel second extraction tanks to alternately feed and discharge; the controller controls the extraction time of each of the second extraction tanks to be 10~30 minutes; Step S7: Using the controller, the second pump on the second pipeline and the third sedimentation separator are turned on to complete the third sedimentation separation operation of the extracted secondary coffee slurry, separating coffee liquid with a TDS of 12%~15%; Using the controller, the third pump on the third pipeline and the disc centrifuge are turned on to introduce the coffee liquid into the disc centrifuge, which separates and purifies the coffee liquid to obtain a coffee liquid product with a TDS of 12%~15%; The coffee grounds discharged from the third sedimentation separator flow into the second mixing tank, and the fourth pump, automatic regulating valve and flow meter on the fourth pipeline are turned on by the controller to provide 5~60℃ clean water for coffee grounds extraction, and the ratio of coffee grounds to clean water is controlled to be 1:1.5~1:3, and a secondary slurry containing grounds is obtained after extraction; The controller is used to turn on the fifth pump and the second sedimentation separator on the fifth pipeline to perform a second sedimentation separation operation on the slag-containing slurry, so as to obtain a liquid-slag separated slurry; the controller is used to turn on the fifth pump to introduce the separated slurry into the slurry tank; The application method for the long-term operation includes steps S1 to S7, wherein the running order of steps S1 to S7 includes simultaneous running or sequential running.

[0016] In a third aspect, the present invention provides a wet-process cold-ground high TDS coffee liquid, which is prepared by the application method of the aforementioned wet-process cold-ground high TDS coffee liquid preparation system; the TDS of the high TDS coffee liquid is 12%~15%; and the coffee bean extraction rate in the high TDS coffee liquid is 25%~30%.

[0017] The application of the technical solution of the present invention has at least the following beneficial effects: (1) The wet cold grinding high TDS coffee liquid preparation system provided by the present invention combines a primary grinding system and a secondary grinding system connected to a controller, making the wet cold grinding operation intelligent. The second metering component can ensure stable feeding of coffee beans. The flow meter and automatic regulating valve installed on the sixth pipeline can accurately control the flow rate of coffee liquid, realizing precise control of the material-liquid ratio between coffee beans and coffee liquid. The second feeding crushing and grinding component can instantly destroy the cell walls of coffee beans in a very small gap, fully releasing the effective substances of coffee beans and dissolving them into the coffee liquid. This process significantly improves subsequent extraction efficiency and yield, producing a coffee liquid with a TDS of 12%~15%, and significantly shortens the extraction time. This reduces the overall extraction time for wet cold-ground coffee to 10~30 minutes during long-term operations, solving the problem of long extraction times associated with existing cold-quenching methods. Furthermore, the combination of a high-concentration primary and secondary grinding system achieves a TDS of 12%~15% in the ground coffee liquid, eliminating the need for or significantly reducing the cost of concentration, thus greatly saving production costs. The reuse of the secondary pulp further enhances the TDS of the coffee product. Additionally, the fine grinding increases the surface area of ​​the coffee particles, allowing for the extraction of more effective substances from the coffee beans, resulting in a significantly improved extraction rate of 25%~30%.

[0018] (2) The application method of the wet cold grinding high TDS coffee liquid preparation system adopted in this invention can not only prepare coffee liquid products with high TDS content and high extraction rate, but also solve the problem of strong bitterness in coffee extracted by the existing hot quenching method. Specifically, this application method does not use high-temperature water grinding and extraction, but only uses 5~60℃ two-slurry grinding of coffee beans, 5~60℃ coffee liquid grinding of coffee beans, and 5~60℃ water extraction to obtain two slurries. The temperature rise during the grinding and extraction processes is ≤5℃, which can better preserve the fruity and floral aroma of the coffee beans. The whole process is carried out at low temperature and normal pressure, with low operating cost and low equipment maintenance cost.

[0019] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of a wet cold-grinding high TDS coffee liquid preparation system in Example 1.

[0022] Explanation of reference numerals: 1. Second metering unit; 2. Third sedimentation separator; 3. Second mixing tank; 4. Disc centrifuge; 5. First pump; 6. Second pump; 7. Third pump; 8. Seventh pump; 9. Fifth pump; 10. Sixth pump; 11. Automatic regulating valve; 12. Second negative pressure pump; 13. Second negative pressure tank; 14. Second bottom valve; 15. Second bean storage tank; 16. Second crushing and grinding machine; 17. Second hopper; 18. Second feeding screw; 19. Second extraction tank; 20. Coffee liquid tank; 21. Second water storage tank; 2 2. First metering unit; 23. First sedimentation separator; 24. First mixing tank; 25. Second sedimentation separator; 26. Pump No. 1; 27. Pump No. 2; 28. Flow meter; 29. ​​Pump No. 4; 30. Pump No. 5; 31. Pump No. 6; 32. First negative pressure pump; 33. First negative pressure tank; 34. First bottom valve; 35. First bean storage tank; 36. First crushing and grinding machine; 37. First hopper; 38. First feeding screw; 39. First extraction tank; 40. Second slurry tank; 41. First water storage tank; 42. Storage tank. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1: See Figure 1 A wet cold-grinding high TDS coffee liquid preparation system includes a primary grinding system, a secondary grinding system, and a controller (specifically, a PLC controller can be selected, which sets grinding process parameters (such as grinding gap and liquid-to-material ratio) and existing CIP process programs; the controller is not shown in the figure). The secondary grinding system includes a second negative pressure bean suction assembly, a second metering component 1, a second feeding crushing and grinding assembly, a second extraction assembly, a third sedimentation separator 2, a second mixing tank 3, a second water supply assembly, a disc centrifuge 4, and a coffee liquid supply assembly. The second negative pressure bean suction assembly includes a second bean suction end and a second bean supply end; the second bean suction end is connected to a storage tank 42 containing coffee beans; the second bean supply end is connected to the feed end of the second metering component 1; the discharge end of the second metering component 1 is connected to the feed end of the second feeding crushing and grinding assembly; the discharge end of the second feeding crushing and grinding assembly is connected to the feed end of the second extraction assembly via a first pipeline; the discharge end of the second extraction assembly is connected to the feed end of the third sedimentation separator 2 via a second pipeline; the liquid outlet end of the third sedimentation separator 2 is connected to the disc type... The inlet of centrifuge 4 is connected; the outlet of disc centrifuge 4 is used to produce coffee liquid; the slag outlet of the third sedimentation separator 2 is connected to the inlet of the second mixing tank 3; the second water supply component is connected to the inlet of the second mixing tank 3 through a fourth pipeline; the outlet of the second mixing tank 3 is used to output the second slurry, and is connected to the second slurry recovery end of the primary grinding system through a fifth pipeline; the outlet of the coffee liquid supply component is connected to the feeding crushing and grinding component through a sixth pipeline, and its inlet is connected to the coffee liquid output end of the primary grinding system through a seventh pipeline; A first pump 5 is installed on the first pipeline; a second pump 6 is installed on the second pipeline; a third pump 7 is installed on the third pipeline; a fourth pump is installed on the fourth pipeline; a fifth pump 9 is installed on the fifth pipeline; a sixth pump 10 is installed on the sixth pipeline; and a seventh pump 8 is installed on the seventh pipeline. The first pump 5 to the seventh pump 8, the second negative pressure bean suction assembly, the second metering component 1, the second feeding crushing and grinding assembly, the second extraction assembly, the third sedimentation separator 2, the second stirring tank 3, the disc centrifuge 4, the second water supply assembly, the coffee liquid supply assembly, and the primary grinding system are all connected to the controller. Automatic regulating valves 11 and flow meters 28 connected to the controller are installed on the fourth and sixth pipelines, respectively, for measuring and regulating the flow rates of clean water and coffee liquid; Automatic regulating valves 11 connected to the controller are installed on the first pipeline, the second pipeline, the third pipeline, the fifth pipeline and the seventh pipeline to regulate the real-time flow.

[0025] The second negative pressure bean suction assembly includes a second negative pressure pump 12, a second negative pressure tank 13, a second bottom valve 14, a second bean storage tank 15, and a second weighing sensor (not shown in the figure); the second negative pressure pump 12 is connected to the second negative pressure tank 13, and the second negative pressure pump 12 is equipped with a second bypass valve; the second bypass valve is connected to the controller; the second negative pressure tank 13 is connected to a storage tank 42 containing coffee beans (the coffee beans are added to the storage tank 42 after screening, washing, and roasting) through a second vacuum tube; the second bean suction end is set on the second vacuum tube; the second bean storage tank 15 is set at the bottom outlet of the second negative pressure tank 13; the second bottom valve 14 is set at the bottom outlet of the second negative pressure tank 13; the second bean storage tank 15 is set on the second frame; the second weighing sensor is set between the second bean storage tank 15 and the second frame; the second bean supply end is set at the bottom outlet of the second bean storage tank 15; the second negative pressure pump 12, the second bottom valve 14, and the second weighing sensor are all connected to the controller; The outlet of the coffee liquid supply component is connected to the second negative pressure tank 13 via an eighth pipeline; the outlet of the coffee liquid supply component is connected to the second bean storage tank 15 via a ninth pipeline; the eighth pipeline and the ninth pipeline are both connected in parallel on the sixth pipeline; an automatic regulating valve 11 connected to the controller is provided on both the eighth pipeline and the ninth pipeline, so that the controller can control the sixth pump 10 on the sixth pipeline and each automatic regulating valve 11 on the eighth pipeline and the ninth pipeline to complete the cleaning of the second negative pressure tank 13 and the second bean storage tank 15.

[0026] The second metering component 1 includes a second metering screw; the feed end of the second metering screw is connected to the second bean supply end; the discharge end of the second metering screw is connected to the second hopper 17 of the second feeding crushing and grinding assembly; the second metering screw is connected to the controller; the second metering screw is a frequency conversion metering screw, which facilitates the control of the coffee bean output. The second feeding crushing and grinding assembly includes a second crushing and grinding mill 16, a second hopper 17, and a second feeding screw 18; the discharge end of the second hopper 17 is set to correspond to the feed end of the second feeding screw 18; the discharge end of the second feeding screw 18 is set to correspond to the feed inlet of the second crushing and grinding mill 16; both the second crushing and grinding mill 16 and the second feeding screw 18 are connected to the controller. The outlet of the coffee liquid supply component is connected to the second metering screw through the tenth pipe; the tenth pipe is arranged in parallel on the sixth pipe; an automatic regulating valve 11 connected to the controller is provided on the tenth pipe, so that the controller can control the sixth pump 10 on the sixth pipe and the automatic regulating valve 11 on the tenth pipe to complete the cleaning of the second metering screw (as well as the second hopper 17, the second feeding screw 18 and the second crushing and grinding mill 16); The outlet of the coffee liquid supply component is connected to the second hopper 17 in the second feeding crushing and grinding component through the sixth pipeline.

[0027] The second extraction assembly includes two second extraction tanks 19 connected in parallel on the first pipeline, and each second extraction tank 19 is connected to the controller; the feed end of each second extraction tank 19 is connected in parallel to the first pipeline through a first branch, and an automatic regulating valve 11 connected to the controller is provided on each first branch; the discharge end of each second extraction tank 19 is connected in parallel to the second pipeline through a second branch, and an automatic regulating valve 11 connected to the controller is provided on each second branch; a stirring motor provided on each second extraction tank 19 is connected to the controller.

[0028] The coffee liquid supply assembly includes a coffee liquid tank 20, the sixth pipeline, and the sixth pump 10 disposed on the sixth pipeline; the sixth pipeline is disposed at the outlet end of the coffee liquid tank 20. The second water supply assembly includes a second water storage tank 21, the fourth pipeline, and the fourth pump installed on the fourth pipeline; one end of the fourth pipeline is connected to the outlet of the second water storage tank 21, and the other end is connected to the inlet of the second mixing tank 3. The third sedimentation separator 2 is a third horizontal spiral sedimentation centrifuge.

[0029] The disc centrifuge is a high-speed centrifugal separation device that can further separate the coffee liquid obtained from the third horizontal spiral sedimentation centrifuge to obtain pure coffee liquid.

[0030] The primary grinding system includes a first negative pressure bean suction assembly, a first metering component 22, a first feeding crushing and grinding assembly, a first extraction assembly, a first sedimentation separator 23, a first mixing tank 24, a first water supply assembly, a second sedimentation separator 25, and a second slurry supply assembly. The first negative pressure bean suction assembly includes a first bean suction end and a first bean supply end; the first bean suction end is connected to a storage tank 42 containing coffee beans; the first bean supply end is connected to the feed end of the first metering component 22; the discharge end of the first metering component 22 is connected to the feed end of the first feeding crushing and grinding assembly; the discharge end of the first feeding crushing and grinding assembly is connected to the feed end of the first extraction assembly via a first pipeline; the discharge end of the first extraction assembly is connected to the feed end of the first sedimentation separator 23 via a second pipeline; the liquid outlet of the first sedimentation separator 23 is the coffee liquid output end of the primary grinding system, which is connected to the liquid inlet of the coffee liquid tank 20 via a seventh pipeline. The first sedimentation separator 23 is connected to the inlet of the first mixing tank 24 via pipeline number three; the first water supply component is connected to the inlet of the first mixing tank 24 via pipeline number three; the outlet of the first mixing tank 24 is used to output the second slurry and is connected to the inlet of the second sedimentation separator 25 via pipeline number four; the inlet of the second sedimentation separator 25 is the second slurry recovery end in the first-stage grinding system; the outlet of the second sedimentation separator 25 is connected to the inlet of the second slurry supply component via pipeline number five, and its slag outlet is used to discharge coffee grounds; the outlet of the second slurry supply component is connected to the first feeding crushing and grinding component via pipeline number six. Pump 26 is installed on pipeline 1; pump 27 is installed on pipeline 2; pump 3 is installed on pipeline 3; pump 29 is installed on pipeline 4; pump 30 is installed on pipeline 5; and pump 31 is installed on pipeline 6. Pumps 26 to 31, the first negative pressure bean suction assembly, the first metering component 22, the first feeding crushing and grinding assembly, the first extraction assembly, the first sedimentation separator 23, the second sedimentation separator 25, the first mixing tank 24, the first water supply assembly, and the second slurry supply assembly are all connected to the controller. Automatic regulating valves 11 and flow meters 28 connected to the controller are installed on both the No. 3 and No. 6 pipelines, respectively for measuring and regulating the flow rates of clean water and coffee liquid; Automatic regulating valves 11 connected to the controller are installed on pipelines 1, 2, 4 and 5 to regulate real-time flow.

[0031] The first negative pressure bean suction assembly includes a first negative pressure pump 32, a first negative pressure tank 33, a first bottom valve 34, a first bean storage tank 35, and a first weighing sensor (not shown in the figure); the first negative pressure pump 32 is connected to the first negative pressure tank 33, and the first negative pressure pump 32 is equipped with a first bypass valve; the first bypass valve is connected to the controller; the first negative pressure tank 33 is connected to a storage tank 42 containing coffee beans (the coffee beans are added to the storage tank 42 after being screened, washed, and roasted) through a first vacuum tube; the first bean suction end is disposed on the first vacuum tube; the first bean storage tank 35 is disposed at the bottom outlet of the first negative pressure tank 33; the first bottom valve 34 is disposed at the bottom outlet of the first negative pressure tank 33; the first bean storage tank 35 is disposed on a first frame; the first weighing sensor is disposed between the first bean storage tank 35 and the first frame; the first bean supply end is disposed at the bottom outlet of the first bean storage tank 35; the first negative pressure pump 32, the first bottom valve 34, and the first weighing sensor are all connected to the controller; The outlet of the second slurry supply component is connected to the first negative pressure tank 33 via pipeline No. 7; the outlet of the second slurry supply component is connected to the first bean storage tank 35 via pipeline No. 8; pipelines No. 7 and No. 8 are both connected in parallel to pipeline No. 6; automatic regulating valves 11 connected to the controller are installed on both pipelines No. 7 and No. 8, so that the controller can control pump No. 6 31 on pipeline No. 6 and each automatic regulating valve 11 on pipelines No. 7 and No. 8 to complete the cleaning of the first negative pressure tank 33 and the first bean storage tank 35.

[0032] The first metering component 22 includes a first metering screw; the feed end of the first metering screw is connected to the first bean supply end; the discharge end of the first metering screw is connected to the first hopper 37 of the first feeding crushing and grinding assembly; the first metering screw is connected to the controller; the first metering screw is a frequency conversion metering screw, which facilitates the control of the coffee bean output. The first feeding crushing and grinding assembly includes a first crushing and grinding mill 36, a first hopper 37, and a first feeding screw 38; the discharge end of the first hopper 37 is set to correspond to the feed end of the first feeding screw 38; the discharge end of the first feeding screw 38 is set to correspond to the feed inlet of the first crushing and grinding mill 36; both the first crushing and grinding mill 36 and the first feeding screw 38 are connected to the controller. Both the first crusher and the second ...

[0033] The CBG(MF) model crusher and grinder combines crushing and grinding functions. It mainly consists of a feeding screw, grinding chamber, main shaft assembly, frame and clearance adjustment mechanism, base, and main motor. The main shaft assembly is the core component of the grinder. The main motor transmits power to the main shaft and turntable via a coupling, driving the grinding discs. The main shaft assembly is mounted on the frame, and the clearance adjustment mechanism and frame bear the axial thrust, which is ≤2.5T. The grinding discs are made of food-grade wear-resistant stainless steel and CNC machined. They can be customized according to the processing characteristics of the materials to meet different process requirements. This structural design ensures efficient operation and precise control of the grinder, meeting the requirements of production processes for precision, stability, and safety, and satisfying the requirements for low material-to-water ratio grinding. Intelligent monitoring and protection of the equipment are achieved through the collaborative work of multiple sensors.

[0034] The outlet of the second slurry supply component is connected to the first metering screw via pipeline number nine; pipeline number nine is connected in parallel to pipeline number six; an automatic regulating valve 11 connected to the controller is installed on pipeline number nine, so that the controller can control the sixth pump 10 on pipeline number six and the automatic regulating valve 11 on pipeline number nine to complete the cleaning of the first metering screw (as well as the first hopper 37, the first feeding screw 38 and the first crushing and grinding mill 36); The outlet of the second slurry supply component is connected to the first hopper 37 in the first feeding crushing and grinding component through the sixth pipeline.

[0035] The first extraction assembly includes two first extraction tanks 39 connected in parallel on the first pipeline, and each first extraction tank 39 is connected to the controller; the feed end of each first extraction tank 39 is connected in parallel to the first pipeline through a first branch, and an automatic regulating valve 11 connected to the controller is provided on each first branch; the discharge end of each first extraction tank 39 is connected in parallel to the second pipeline through a second branch, and an automatic regulating valve 11 connected to the controller is provided on each second branch; a stirring motor provided on each first extraction tank 39 is connected to the controller.

[0036] The second slurry supply assembly includes a second slurry tank 40, the sixth pipeline, and the sixth pump 31 installed on the sixth pipeline; the sixth pipeline is located at the outlet end of the second slurry tank 40. The first water supply component includes a first water storage tank 41, the third pipeline, and the third pump installed on the third pipeline; one end of the third pipeline is connected to the outlet of the first water storage tank 41, and the other end is connected to the inlet of the first mixing tank 24. The first sedimentation separator 23 is a first horizontal spiral sedimentation centrifuge; The second sedimentation separator 25 is a second horizontal spiral sedimentation centrifuge.

[0037] The application methods of the wet cold-grinding high TDS coffee liquid preparation system include application methods for initial operation and application methods for long-term operation: The application method of the initial task includes: Step S1: The controller starts the first negative pressure pump 32 to create a vacuum in the first negative pressure tank 33, and controls the first bottom valve 34 to close at the bottom outlet of the first negative pressure tank 33. Coffee beans are drawn into the first negative pressure tank 33 through the first vacuum tube until the weight of the coffee beans in the first negative pressure tank 33 is greater than the opening pressure of the first bottom valve 34. Then the controller controls the first bottom valve 34 to open, and the coffee beans fall into the first bean storage tank 35. The first weighing sensor monitors the weight of coffee beans in the first bean storage tank 35 in real time and transmits the data to the controller. When the weight reaches the upper limit of the preset weight value of the controller, the controller opens the first bypass valve and the first negative pressure pump 32 stops sucking beans. When the weight reaches the lower limit of the preset weight value of the controller, the controller closes the first bypass valve and the first negative pressure pump 32 continues to suck beans. Step S2: Using the controller, open the bottom outlet of the first bean storage tank 35, the first metering screw, the first feeding screw 38, and the first crusher / grinder 36, and control the grinding gap of the first crusher / grinder 36 to be 10~50 (specifically 30) μm to grind the coffee beans. From coffee beans to coffee paste, the entire process takes only ten seconds to obtain a coffee paste containing 50~100 (specifically 76.3) μm of coffee residue. Specifically, the food-grade metal grinding discs of the first crusher / grinder 36, rotating at high speed, instantly break down the cell walls of the coffee beans within a very small gap, thus grinding the coffee beans... The effective substances are fully released and dissolved into the secondary slurry, which facilitates the improvement of subsequent extraction efficiency and extraction rate. When grinding coffee beans, the controller is used to open the sixth pump 31, automatic regulating valve 11 and flow meter 28 on the sixth pipeline to provide the secondary slurry at 5~60 (specifically 60)℃ for the coffee bean grinding operation, and control the material-liquid ratio (i.e. material-liquid mass ratio) of coffee beans to secondary slurry at 1:3~1:5 (specifically 1:4) to facilitate grinding to obtain a primary coffee slurry with a TDS of 6%~8% (specifically 7%). The output of the primary coffee slurry is 1~10 (specifically 4) tons / hour. Step S3: Using the controller, turn on the first pump 26 on the first pipeline and each of the first extraction tanks 39 to complete the extraction of the first-stage coffee slurry; wherein, the controller controls the parallel first extraction tanks 39 to alternately feed and discharge; the controller controls the extraction time of each of the first extraction tanks 39 to be 10~30 (specifically 30) min to ensure that the coffee fully absorbs water, swells, and precipitates coffee-soluble substances; Step S4: Using the controller, turn on the second pump 27 on the second pipeline and the first sedimentation separator 23 to complete the first sedimentation separation operation of the extracted primary coffee slurry and separate the coffee liquid; use the controller to turn on the automatic regulating valve 11 on the seventh pipeline to introduce the coffee liquid into the coffee liquid tank 20; The coffee grounds discharged from the first sedimentation separator 23 flow into the first mixing tank 24. The controller is used to turn on the third pump, the automatic regulating valve 11 and the flow meter 28 on the third pipeline to provide clean water at 5~60 (specifically 60)℃ for coffee grounds extraction, and the ratio of coffee grounds to clean water is controlled to be 1:1.5~1:3 (specifically 1:2). After extraction, a second slurry containing grounds is obtained. The controller is used to turn on the fourth pump 29 and the second sedimentation separator 25 to perform a second sedimentation separation operation on the slag-containing slurry, so as to obtain a liquid-slag separated slurry; the controller is used to turn on the fifth pump 30 to introduce the separated slurry into the slurry tank 40; Step S5: The controller starts the second negative pressure pump 12 to create a vacuum in the second negative pressure tank 13, and controls the second bottom valve 14 to close at the bottom outlet of the second negative pressure tank 13. Coffee beans are drawn into the second negative pressure tank 13 through the second vacuum tube until the weight of the coffee beans in the second negative pressure tank 13 is greater than the opening pressure of the second bottom valve 14. Then the controller controls the second bottom valve 14 to open, and the coffee beans fall into the second bean storage tank 15. The second weighing sensor monitors the weight of coffee beans in the second bean storage tank 15 in real time and transmits the data to the controller. When the weight reaches the upper limit of the preset weight value of the controller, the controller opens the second bypass valve and the second negative pressure pump 12 stops sucking beans. When the weight reaches the lower limit of the preset weight value of the controller, the controller closes the second bypass valve and the second negative pressure pump 12 continues to suck beans. The controller opens the bottom outlet of the second bean storage tank 15, the second metering screw, the second feeding screw 18, and the second crusher / grinder 16, and controls the grinding gap of the second crusher / grinder 16 to be 10~50 (specifically 30) μm, thus grinding the coffee beans. From coffee beans to coffee pulp, the entire process takes only ten seconds to obtain a concentrated coffee pulp containing 50~100 (specifically 76.3) μm of coffee grounds. Specifically, the food-grade metal grinding discs of the second crusher / grinder 16, rotating at high speed, instantly break down the cell walls of the coffee beans within a very small gap, releasing the effective substances from the coffee beans. The coffee beans are fully released and dissolved into the coffee liquid, which facilitates improved extraction efficiency and extraction rate in subsequent processes. During coffee bean grinding, the controller activates the sixth pump 10, automatic regulating valve 11, and flow meter 28 on the sixth pipeline to provide coffee liquid at 5-60°C (specifically 60°C) for the grinding operation. The ratio of coffee beans to coffee liquid (i.e., the mass ratio of coffee beans to liquid) is controlled at 1:3 to 1:5 (specifically 1:4) to facilitate grinding and obtaining a secondary coffee slurry with a TDS of 12%-15% (specifically 12.8%). The production capacity of the secondary coffee slurry is 1-10 (specifically 2) tons / hour. Step S6: Using the controller, open the first pump 5 on the first pipeline and each of the second extraction tanks 19 to complete the extraction of the secondary coffee slurry; wherein, the controller controls the parallel second extraction tanks 19 to alternately feed and discharge; the controller controls the extraction time of each second extraction tank 19 to be 10~30min (specifically 30min) to ensure that the coffee fully absorbs water, swells, and precipitates coffee-soluble substances; Step S7: Using the controller, the second pump 6 on the second pipeline and the third sedimentation separator 2 are turned on to complete the third sedimentation separation operation of the extracted secondary coffee slurry, separating coffee liquid with a TDS of 12%~15% (specifically 12.8%); Using the controller, the third pump 7 on the third pipeline and the disc centrifuge 4 are turned on to introduce the coffee liquid into the disc centrifuge 4, where it is separated and purified to obtain a TDS of 12%~15% (specifically 12.8%). The coffee liquid product (12.8%) can be packaged or pumped to the next process for further concentration or freeze-drying. The coffee grounds discharged from the third sedimentation separator 2 flow into the second mixing tank 3. The controller is used to open the fourth pump, automatic regulating valve 11 and flow meter 28 on the fourth pipeline to provide 5~60 (specifically 60)℃ clean water for coffee grounds extraction, and the ratio of coffee grounds to clean water is controlled to be 1:1.5~1:3 (specifically 1:2). After extraction, a slurry containing grounds is obtained. The controller is used to open the fifth pump 9 and the second sedimentation separator 25 on the fifth pipeline to perform a second sedimentation separation operation on the slag-containing slurry, so as to obtain a slurry with liquid-slag separation; the controller is used to open the fifth pump 30 to introduce the separated slurry into the slurry tank 40; The application method for long-term operation includes steps S1 to S7, wherein the running order of steps S1 to S7 includes simultaneous running or sequential running, and the specific running order is adjusted by the controller according to the actual situation.

[0038] The high TDS coffee liquid prepared using the wet cold grinding high TDS coffee liquid preparation system described in Example 1 was sampled and subjected to TDS content testing, extraction rate calculation, and particle size testing. The TDS content was measured directly using an SW-21C coffee concentration meter manufactured by Guangzhou Suwei Electronic Technology Co., Ltd.

[0039] The extraction rate was calculated with reference to existing literature (Tang Wenxiao, Xiao Ying, Jiang Tianning, Jiang Feng, Zhu Jing, Zhou Yiming. Effects of roasting degree on physicochemical indicators and flavor components of cold brew coffee [J]. Food Science and Technology, 2022, 43(23):239-248.). The specific calculation formula is as follows: Extraction rate / % = (TDS / % × coffee liquid mass / g) ÷ coffee bean mass / g × 100. Particle size was measured using a laser particle size analyzer, model LT2100 Plus, manufactured by Zhuhai Zhenli Optical Instrument Co., Ltd. 1-2 mL of sample was added to the injector, ensuring an opacity of 8%-10%, and the sample was examined, with data read and recorded.

[0040] The test results are shown in Table 1.

[0041] Table 1 Test Results of Example 1 Example 2: Unlike Example 1, the water temperature used in steps S4 and S7 is changed from 60°C to 25°C.

[0042] Comparative Example 1 (Cold Quenching Method): First, coffee beans are screened, washed, and roasted, then ground in a roller mill to obtain powdered coffee with a relatively large particle size (200-600 μm). Second, the ground coffee powder is extracted into coffee liquid using a cold quenching method. In this method, cold water is used as the extraction medium at 5°C, the ratio of coffee powder to hot water (mass ratio) is controlled at 1:16, the pH of the extraction system is controlled at 5.13-5.82, and the extraction time is 16 hours.

[0043] Comparative Example 2 (Hot Quenching Method): First, coffee beans are screened, washed, and roasted, then ground in a roller mill to obtain powdered coffee with a relatively large particle size (200-600 μm). Second, the ground coffee powder is extracted into coffee liquid using a hot quenching method. In this method, hot water is used as the extraction medium at 92°C, the ratio of coffee powder to hot water (mass ratio) is controlled at 1:16, the pH of the extraction system is controlled at 4.99-5.67, and the extraction time is 3 minutes.

[0044] The process parameters used in Comparative Examples 1 and 2, the TDS (Total Dissolved Solids) of the prepared coffee liquid products, and the extraction rate were statistically analyzed, as shown in Table 2. Comparative Examples 1 and 2 and their data were obtained from existing literature (Jiang Tianning. Research on the Influence of Roasting Degree and Water Quality on the Quality of Cold Brew Coffee [D]. Shanghai: Shanghai University of Applied Technology, 2021.). Table 2 also shows the relevant data for Examples 1 and 2 (specifically, the ratio of coffee beans to coffee liquid, water temperature, extraction time during the long-term operation phase, and the TDS and extraction rate of the coffee liquid products).

[0045] Table 2 Statistical results for Examples 1-2 and Comparative Examples 1-2 As shown in Tables 1 and 2, compared to the cold quenching method in Comparative Example 1 and the hot quenching method in Comparative Example 2, the coffee liquid products prepared using Examples 1 and 2 of this invention exhibit higher TDS content and extraction rates. This indicates that: In Example 1 of this invention, both the first and second feeding crushing and grinding components can instantly break down the cell walls of coffee beans with extremely small gaps, fully releasing the effective substances in the coffee beans to obtain a high-concentration coffee liquid. This can greatly improve the subsequent extraction efficiency and extraction rate, and significantly shorten the extraction time. In addition, the coffee beans are ground with a higher concentration of coffee liquid in the two-stage grinding system, resulting in a higher TDS level in the ground coffee liquid. Furthermore, Example 1 also uses secondary pulp recycling, which further improves the TDS of the coffee liquid product.

[0046] The above description is only a preferred embodiment of the present invention and does not limit the scope of the present invention. All equivalent structural transformations made under the inventive concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the protection scope of the present invention.

Claims

1. A system for preparing high TDS coffee liquid using wet cold grinding, characterized in that, Includes a primary grinding system, a secondary grinding system, and a controller; The secondary grinding system includes a second negative pressure bean suction assembly, a second metering component (1), a second feeding crushing and grinding assembly, a second extraction assembly, a third sedimentation separator (2), a second mixing tank (3), a second water supply assembly, a disc centrifuge (4), and a coffee liquid supply assembly. The second negative pressure bean suction assembly includes a second bean suction end and a second bean supply end; the second bean suction end is connected to a storage tank (42) containing coffee beans; the second bean supply end is connected to the feed end of the second metering component (1); the discharge end of the second metering component (1) is connected to the feed end of the second feeding crushing and grinding assembly; the discharge end of the second feeding crushing and grinding assembly is connected to the feed end of the second extraction assembly through a first pipeline; the discharge end of the second extraction assembly is connected to the feed end of the third sedimentation separator (2) through a second pipeline; the liquid outlet end of the third sedimentation separator (2) is connected to the disc separator through a third pipeline. The inlet end of the centrifuge (4) is connected; the outlet end of the disc centrifuge (4) is used to produce coffee liquid; the slag outlet end of the third sedimentation separator (2) is connected to the inlet of the second mixing tank (3); the second water supply component is connected to the inlet of the second mixing tank (3) through the fourth pipeline; the outlet of the second mixing tank (3) is used to output the second slurry, and is connected to the second slurry recovery end of the first-stage grinding system through the fifth pipeline; the outlet end of the coffee liquid supply component is connected to the feeding crushing and grinding component through the sixth pipeline, and its inlet end is connected to the coffee liquid output end of the first-stage grinding system through the seventh pipeline; A first pump (5) is installed on the first pipeline; a second pump (6) is installed on the second pipeline; a third pump (7) is installed on the third pipeline; a fourth pump is installed on the fourth pipeline; a fifth pump (9) is installed on the fifth pipeline; a sixth pump (10) is installed on the sixth pipeline; and a seventh pump (8) is installed on the seventh pipeline. The first pump (5) to the seventh pump (8), the second negative pressure bean suction assembly, the second metering component (1), the second feeding crushing and grinding assembly, the second extraction assembly, the third sedimentation separator (2), the second stirring tank (3), the disc centrifuge (4), the second water supply assembly, the coffee liquid supply assembly, and the first-stage grinding system are all connected to the controller; An automatic regulating valve (11) and a flow meter (28) connected to the controller are installed on both the fourth and sixth pipelines. Automatic regulating valves (11) connected to the controller are installed on the first pipeline, the second pipeline, the third pipeline, the fifth pipeline and the seventh pipeline.

2. The wet cold-grinding high TDS coffee liquid preparation system as described in claim 1, characterized in that, The second negative pressure bean suction assembly includes a second negative pressure pump (12), a second negative pressure tank (13), a second bottom valve (14), a second bean storage tank (15), and a second weighing sensor; the second negative pressure pump (12) is connected to the second negative pressure tank (13), and the second negative pressure pump (12) is equipped with a second bypass valve; the second bypass valve is connected to the controller; the second negative pressure tank (13) is connected to a storage tank (42) containing coffee beans through a second vacuum tube; the second bean suction end is disposed on the second vacuum tube; the second bean storage tank ( 15) The bottom outlet of the second negative pressure tank (13) is provided; the second bottom valve (14) is openable and closable on the bottom outlet of the second negative pressure tank (13); the second bean storage tank (15) is provided on the second frame; the second weighing sensor is provided between the second bean storage tank (15) and the second frame; the second bean supply end is provided on the bottom outlet of the second bean storage tank (15); the second negative pressure pump (12), the second bottom valve (14) and the second weighing sensor are all connected to the controller; The outlet of the coffee liquid supply component is connected to the second negative pressure tank (13) through the eighth pipeline; the outlet of the coffee liquid supply component is connected to the second bean storage tank (15) through the ninth pipeline; the eighth pipeline and the ninth pipeline are both arranged in parallel on the sixth pipeline; an automatic regulating valve (11) connected to the controller is provided on both the eighth pipeline and the ninth pipeline.

3. The wet cold-grinding high TDS coffee liquid preparation system as described in claim 2, characterized in that, The second metering component (1) includes a second metering screw; the feed end of the second metering screw is connected to the second bean supply end; the discharge end of the second metering screw is connected to the second hopper (17) of the second feeding crushing and grinding assembly; the second metering screw is connected to the controller; the second metering screw is a frequency conversion metering screw; The second feeding crushing and grinding assembly includes a second crushing and grinding mill (16), a second hopper (17), and a second feeding screw (18); the discharge end of the second hopper (17) is set to correspond to the feed end of the second feeding screw (18); the discharge end of the second feeding screw (18) is set to correspond to the feed inlet of the second crushing and grinding mill (16); both the second crushing and grinding mill (16) and the second feeding screw (18) are connected to the controller; The outlet of the coffee liquid supply component is connected to the second metering spiral through the tenth pipeline; the tenth pipeline is arranged in parallel on the sixth pipeline; an automatic regulating valve (11) connected to the controller is provided on the tenth pipeline. The outlet of the coffee liquid supply component is connected to the second hopper (17) in the second feeding crushing and grinding component through the sixth pipeline.

4. The wet cold-grinding high TDS coffee liquid preparation system as described in claim 3, characterized in that, The second extraction assembly includes two second extraction tanks (19) connected in parallel on the first pipeline, and each second extraction tank (19) is connected to the controller; the feed end of each second extraction tank (19) is connected in parallel to the first pipeline through a first branch, and an automatic regulating valve (11) connected to the controller is provided on each first branch; the discharge end of each second extraction tank (19) is connected in parallel to the second pipeline through a second branch, and an automatic regulating valve (11) connected to the controller is provided on each second branch. The coffee liquid supply assembly includes a coffee liquid tank (20), the sixth pipeline, and the sixth pump (10) disposed on the sixth pipeline; the sixth pipeline is disposed at the outlet end of the coffee liquid tank (20); The second water supply assembly includes a second water storage tank (21), the fourth pipeline and the fourth pump installed on the fourth pipeline; one end of the fourth pipeline is connected to the outlet of the second water storage tank (21), and the other end is connected to the inlet of the second mixing tank (3); The third sedimentation separator (2) is a third horizontal spiral sedimentation centrifuge.

5. The wet cold-grinding high TDS coffee liquid preparation system as described in claim 4, characterized in that, The primary grinding system includes a first negative pressure bean suction assembly, a first metering component (22), a first feeding crushing and grinding assembly, a first extraction assembly, a first sedimentation separator (23), a first mixing tank (24), a first water supply assembly, a second sedimentation separator (25), and a second slurry supply assembly; The first negative pressure bean suction assembly includes a first bean suction end and a first bean supply end; the first bean suction end is connected to a storage tank (42) containing coffee beans; the first bean supply end is connected to the feed end of the first metering component (22); the discharge end of the first metering component (22) is connected to the feed end of the first feeding crushing and grinding assembly; the discharge end of the first feeding crushing and grinding assembly is connected to the feed end of the first extraction assembly through a first pipeline; the discharge end of the first extraction assembly is connected to the feed end of the first sedimentation separator (23) through a second pipeline; the liquid outlet of the first sedimentation separator (23) is the coffee liquid output end of the primary grinding system, which is connected to the liquid inlet of the coffee liquid tank (20) through a seventh pipeline. The first sedimentation separator (23) is connected to the slag outlet of the first mixing tank (24) through pipeline No. 3; the first water supply component is connected to the inlet of the first mixing tank (24) through pipeline No. 3; the outlet of the first mixing tank (24) is used to output the second slurry and is connected to the inlet of the second sedimentation separator (25) through pipeline No. 4; the inlet of the second sedimentation separator (25) is the second slurry recovery end in the first-stage grinding system; the outlet of the second sedimentation separator (25) is connected to the inlet of the second slurry supply component through pipeline No. 5, and its slag outlet is used to discharge coffee grounds; the outlet of the second slurry supply component is connected to the first feeding crushing and grinding component through pipeline No.

6. Pump No. 1 (26) is installed on pipeline No. 1; pump No. 2 (27) is installed on pipeline No. 2; pump No. 3 is installed on pipeline No. 3; pump No. 4 (29) is installed on pipeline No. 4; pump No. 5 (30) is installed on pipeline No. 5; pump No. 6 (31) is installed on pipeline No.

6. Pump No. 1 (26) to Pump No. 6 (31), the first negative pressure bean suction assembly, the first metering component (22), the first feeding crushing and grinding assembly, the first extraction assembly, the first sedimentation separator (23), the second sedimentation separator (25), the first mixing tank (24), the first water supply assembly and the second slurry supply assembly are all connected to the controller; Automatic regulating valves (11) and flow meters (28) connected to the controller are installed on both the No. 3 and No. 6 pipelines. Automatic regulating valves (11) connected to the controller are installed on the first pipeline, the second pipeline, the fourth pipeline and the fifth pipeline.

6. The wet cold-grinding high TDS coffee liquid preparation system as described in claim 5, characterized in that, The first negative pressure bean suction assembly includes a first negative pressure pump (32), a first negative pressure tank (33), a first bottom valve (34), a first bean storage tank (35), and a first weighing sensor; the first negative pressure pump (32) is connected to the first negative pressure tank (33), and the first negative pressure pump (32) is equipped with a first bypass valve; the first bypass valve is connected to the controller; the first negative pressure tank (33) is connected to a storage tank (42) containing coffee beans through a first vacuum tube; the first bean suction end is disposed on the first vacuum tube; the first bean storage tank (34) 35) The bottom outlet of the first negative pressure tank (33) is provided; the first bottom valve (34) is openable and closable on the bottom outlet of the first negative pressure tank (33); the first bean storage tank (35) is provided on the first frame; the first weighing sensor is provided between the first bean storage tank (35) and the first frame; the first bean supply end is provided on the bottom outlet of the first bean storage tank (35); the first negative pressure pump (32), the first bottom valve (34) and the first weighing sensor are all connected to the controller; The outlet of the second slurry supply component is connected to the first negative pressure tank (33) through pipeline No. 7; the outlet of the second slurry supply component is connected to the first soybean storage tank (35) through pipeline No. 8; pipeline No. 7 and pipeline No. 8 are both connected in parallel on pipeline No. 6; automatic regulating valves (11) connected to the controller are provided on pipeline No. 7 and pipeline No.

8.

7. The wet cold-grinding high TDS coffee liquid preparation system as described in claim 6, characterized in that, The first metering component (22) includes a first metering screw; the feed end of the first metering screw is connected to the first bean supply end; the discharge end of the first metering screw is connected to the first hopper (37) of the first feeding crushing and grinding assembly; the first metering screw is connected to the controller; the first metering screw is a frequency conversion metering screw. The first feeding crushing and grinding assembly includes a first crushing and grinding mill (36), a first hopper (37), and a first feeding screw (38); the discharge end of the first hopper (37) is set to correspond to the feed end of the first feeding screw (38); the discharge end of the first feeding screw (38) is set to correspond to the feed inlet of the first crushing and grinding mill (36); the first feeding screw (38) is connected to the controller; The outlet end of the second slurry supply component is connected to the first metering screw through pipeline number nine; pipeline number nine is connected in parallel to pipeline number six; an automatic regulating valve (11) connected to the controller is installed on pipeline number nine. The outlet end of the second slurry supply component is connected to the first hopper (37) in the first feeding crushing and grinding component through the sixth pipeline.

8. The wet cold-grinding high TDS coffee liquid preparation system as described in claim 7, characterized in that, The first extraction assembly includes two first extraction tanks (39) arranged in parallel on the first pipeline, and each first extraction tank (39) is connected to the controller; the feed end of each first extraction tank (39) is connected in parallel to the first pipeline through a first branch, and an automatic regulating valve (11) connected to the controller is provided on each first branch; the discharge end of each first extraction tank (39) is arranged in parallel on the second pipeline through a second branch, and an automatic regulating valve (11) connected to the controller is provided on each second branch. The second slurry supply assembly includes a second slurry tank (40), the sixth pipeline, and the sixth pump (31) installed on the sixth pipeline; the sixth pipeline is installed at the outlet end of the second slurry tank (40); The first water supply component includes a first water storage tank (41), the third pipeline and the third pump installed on the third pipeline; one end of the third pipeline is connected to the outlet of the first water storage tank (41), and the other end is connected to the inlet of the first mixing tank (24). The first sedimentation separator (23) is a first horizontal spiral sedimentation centrifuge; The second sedimentation separator (25) is a second horizontal spiral sedimentation centrifuge.

9. A method for applying the wet cold-grinding high TDS coffee liquid preparation system as described in claim 8, characterized in that, This includes application methods for initial tasks and application methods for long-term tasks: The application method of the initial task includes: Step S1: The controller starts the first negative pressure pump (32) to create a vacuum in the first negative pressure tank (33) to form a negative pressure, and controls the first bottom valve (34) to close at the bottom outlet of the first negative pressure tank (33). The coffee beans are drawn into the first negative pressure tank (33) through the first vacuum tube until the weight of the coffee beans in the first negative pressure tank (33) is greater than the opening pressure of the first bottom valve (34). The controller then controls the first bottom valve (34) to open, and the coffee beans fall into the first bean storage tank (35). The weight of coffee beans in the first bean storage tank (35) is monitored in real time by the first weighing sensor and transmitted to the controller. When the weight reaches the upper limit of the preset weight value of the controller, the controller opens the first bypass valve and the first negative pressure pump (32) stops sucking beans. When the weight reaches the lower limit of the preset weight value of the controller, the controller closes the first bypass valve and the first negative pressure pump (32) continues to suck beans. Step S2: Using the controller, open the bottom outlet of the first bean storage tank (35), the first metering screw, the first feeding screw (38), and the first crusher and grinder (36), and control the grinding gap of the first crusher and grinder (36) to be 10~50μm to grind the coffee beans; when grinding the coffee beans, use the controller to open the sixth pump (31), the automatic regulating valve (11), and the flow meter (28) on the sixth pipeline to provide the second slurry at 5~60℃ for the coffee bean grinding operation, and control the ratio of coffee beans to the second slurry to be 1:3~1:5 to facilitate grinding to obtain a first-grade coffee slurry with a TDS of 6%~8%; the output of the first-grade coffee slurry is 1~10 tons / hour; Step S3: Use the controller to turn on the first pump (26) on the first pipeline and each of the first extraction tanks (39) to complete the extraction of the first-stage coffee slurry; wherein, the controller controls the parallel first extraction tanks (39) to alternately feed and discharge; the controller controls the extraction time of each of the first extraction tanks (39) to be 10~30min. Step S4: Use the controller to open the second pump (27) on the second pipeline and the first sedimentation separator (23) to complete the first sedimentation separation operation of the extracted first-stage coffee slurry and separate the coffee liquid; use the controller to open the automatic regulating valve (11) on the seventh pipeline to introduce the coffee liquid into the coffee liquid tank (20); The coffee grounds discharged from the first sedimentation separator (23) flow into the first mixing tank (24). The controller is used to open the third pump, the automatic regulating valve (11) and the flow meter (28) on the third pipeline to provide 5~60℃ clean water for coffee grounds extraction, and the ratio of coffee grounds to clean water is controlled to be 1:1.5~1:

3. After extraction, a second slurry containing grounds is obtained. The controller is used to turn on the No. 4 pump (29) and the second sedimentation separator (25) to perform a second sedimentation separation operation on the slag-containing slurry to obtain a liquid-slag separated slurry; the controller is used to turn on the No. 5 pump (30) to introduce the separated slurry into the slurry tank (40); Step S5: The controller starts the second negative pressure pump (12) to create a vacuum in the second negative pressure tank (13) and controls the second bottom valve (14) to close at the bottom outlet of the second negative pressure tank (13). The coffee beans are drawn into the second negative pressure tank (13) through the second vacuum tube until the weight of the coffee beans in the second negative pressure tank (13) is greater than the opening pressure of the second bottom valve (14). The controller then controls the second bottom valve (14) to open, and the coffee beans fall into the second bean storage tank (15). The second weighing sensor is used to monitor the weight of coffee beans in the second bean storage tank (15) in real time and transmit it to the controller; when the weight reaches the upper limit of the weight preset value of the controller, the controller opens the second bypass valve and the second negative pressure pump (12) stops sucking beans; when the weight reaches the lower limit of the weight preset value of the controller, the controller closes the second bypass valve and the second negative pressure pump (12) continues to suck beans. The controller is used to open the bottom outlet of the second bean storage tank (15), the second metering screw, the second feeding screw (18), and the second crusher and grinder (16), and to control the grinding gap of the second crusher and grinder (16) to be 10~50μm, so as to grind the coffee beans; when grinding the coffee beans, the controller is used to open the sixth pump (10), the automatic regulating valve (11), and the flow meter (28) on the sixth pipeline to provide coffee liquid at 5~60℃ for the coffee bean grinding operation, and to control the ratio of coffee beans to coffee liquid to be 1:3~1:5, so as to facilitate grinding to obtain a secondary coffee slurry with a TDS of 12%~15%; the output of the secondary coffee slurry is 1~10 tons / hour; Step S6: Use the controller to open the first pump (5) on the first pipeline and each of the second extraction tanks (19) to complete the extraction of the secondary coffee slurry; wherein, the controller controls the parallel second extraction tanks (19) to alternately feed and discharge; the controller controls the extraction time of each of the second extraction tanks (19) to be 10~30min; Step S7: Using the controller, open the second pump (6) on the second pipeline and the third sedimentation separator (2) to complete the third sedimentation separation operation of the secondary coffee slurry after extraction, and separate coffee liquid with TDS of 12%~15%; Using the controller, open the third pump (7) on the third pipeline and the disc centrifuge (4) to introduce the coffee liquid into the disc centrifuge (4), and after separation and purification by the disc centrifuge (4), obtain coffee liquid product with TDS of 12%~15%; The coffee grounds discharged from the third sedimentation separator (2) flow into the second mixing tank (3), and use the controller to open the fourth pump, automatic regulating valve (11) and flow meter (28) on the fourth pipeline to provide 5~60℃ clean water for coffee grounds extraction, and control the ratio of coffee grounds to clean water to 1:1.5~1:3, and obtain a secondary slurry containing grounds after extraction; The controller is used to open the fifth pump (9) on the fifth pipeline and the second sedimentation separator (25) to perform a second sedimentation separation operation on the slag-containing slurry to obtain a liquid-slag separated slurry; the controller is used to open the fifth pump (30) to introduce the separated slurry into the slurry tank (40); The application method for the long-term operation includes steps S1 to S7, wherein the running order of steps S1 to S7 includes simultaneous running or sequential running.

10. A wet-process cold-ground high TDS coffee liquid, characterized in that, The coffee liquid is prepared using the wet cold grinding high TDS coffee liquid preparation system as described in claim 9; the TDS of the high TDS coffee liquid is 12%~15%; and the coffee bean extraction rate in the high TDS coffee liquid is 25%~30%.

Images