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CN-121988070-A - Supercritical CO2Low-caffeine treatment equipment and method combining molecular sieve directional adsorption

CN121988070ACN 121988070 ACN121988070 ACN 121988070ACN-121988070-A

Abstract

The invention relates to the technical field of coffee bean treatment, in particular to a low-caffeine treatment device and a method for directional adsorption of supercritical CO 2 combined with molecular sieves, which comprises an extraction kettle, a fluid circulation mechanism and a treatment tank which are arranged at the left side and the right side of the extraction kettle, the extraction kettle comprises a kettle body for allowing CO 2 fluid to flow from bottom to top and for placing coffee beans, a filter cylinder arranged at the center of the inside of the kettle body, and an auger arranged inside the filter cylinder. According to the invention, the dynamic circulation extraction structure of the coffee beans is constructed by the auger and the filter cylinder which are arranged in the extraction kettle and driven by the motor, the coffee beans continuously rise in the filter cylinder under the lifting action of the auger and uniformly scatter from the top end, and the coffee beans form countercurrent and dynamic full contact with the supercritical CO 2 which is introduced from the bottom of the kettle and flows upwards, so that the traditional static soaking mode is changed, the contact area and the updating frequency of the coffee beans and the solvent are increased, the single-batch processing time is shortened, and the situation of partial excessive extraction or insufficient extraction is avoided.

Inventors

  • XIAO MINGKUN
  • ZHANG XIAOFANG
  • ZHOU YINGCHUN
  • LOU YUQIANG
  • WANG LIJUN

Assignees

  • 云南那姆咖啡有限公司

Dates

Publication Date
20260508
Application Date
20260331

Claims (10)

  1. 1. The low-caffeine treatment equipment combining supercritical CO 2 with molecular sieve directional adsorption is characterized by comprising an extraction kettle, and a fluid circulation mechanism and a treatment tank which are arranged at the left side and the right side of the extraction kettle; The extraction kettle comprises a kettle body for enabling CO 2 fluid to circulate from bottom to top and for placing coffee beans, a filter cylinder arranged in the center of the kettle body, and an auger arranged in the filter cylinder, wherein the auger lifts the coffee beans in the filter cylinder after rotating and falls back from the top end of the filter cylinder to dynamically contact with the CO 2 fluid; the treatment tank comprises a rotary drum, three adsorption filter elements which are regularly arranged in the rotary drum and selectively adsorb caffeine molecules, and a driving part for driving the rotary drum to rotate at fixed intervals; The drive part comprises a rotating shaft, a ratchet wheel sleeved on the outer wall of the rotating shaft, a plurality of pawls arranged on the outer side of the ratchet wheel and rotating on the inner wall of the circular groove on the top surface of the rotary drum, a lifting ring arranged below the ratchet wheel and an inner convex rod arranged on the inner wall of the lifting ring, wherein the outer wall of the rotating shaft is provided with a cam groove near the center, after the rotating shaft rotates positively, the inner convex rod drives the lifting ring to move up and down along the track of the cam groove, and drives three adsorption filter elements to synchronously move, and after the rotating shaft rotates reversely, the ratchet wheel props against the pawls to adjust the positions of the three adsorption filter elements by driving the rotary drum to rotate.
  2. 2. The apparatus for treating low caffeine by combining supercritical CO 2 with molecular sieve directional adsorption according to claim 1, wherein the extraction kettle further comprises a kettle body, a top plate fixedly connected to the top surface of the kettle body through bolts, a sealing plate fixedly connected to the inner wall of the kettle body near the top end, a bottom plate fixedly connected to the bottom surface of the kettle body through a hoop, a first motor fixedly connected to the top surface of the top plate through bolts and coaxially connected with the central shaft of the auger, and a scraper fixedly connected to the bottom end of the central shaft of the auger.
  3. 3. The device for treating low caffeine by combining supercritical CO 2 with molecular sieve directional adsorption according to claim 2, wherein the bottom ends of the outer walls of the left and right ends of the kettle body and the bottom end close to the top end are respectively welded with a liquid inlet and a liquid outlet, the height of the liquid outlet is positioned below the sealing plate, the filter cartridge is fixedly connected with the kettle body through round bars of the outer walls of the upper and lower ends of the filter cartridge, and the upper and lower ends of the auger extend to the outer sides of the filter cartridge respectively.
  4. 4. The apparatus for treating low caffeine by combining supercritical CO 2 with molecular sieve directional adsorption according to claim 3, wherein the treating tank further comprises a tank body and an adsorption part for providing a rotating section for the rotary drum, three regularly distributed through holes are formed in the rotary drum, and three sliding grooves communicated with the through holes are formed in the inner wall of the rotary drum.
  5. 5. The apparatus for targeted adsorption of supercritical CO 2 combined with molecular sieves, as set forth in claim 4, wherein the adsorption unit comprises a sleeve for clamping and fixing the adsorption filter element, the sleeve is slidably connected to the inside of the through hole, and the inner wall of the sleeve is fixedly connected with a fixing block with an end extending to the inner side of the chute through a bolt.
  6. 6. The apparatus for treating low caffeine by combining supercritical CO 2 with molecular sieve orientation adsorption according to claim 5, wherein the driving part further comprises a second motor and a swivel sleeved outside the lifting ring, the rotating shaft is fixedly connected with an output shaft of the second motor through bolts, the ratchet wheel is fixedly connected to an outer wall of the rotating shaft through a bayonet lock, and the pawl is rotatably connected in a groove on an inner wall of a circular groove on the top surface of the rotating drum.
  7. 7. The apparatus for targeted adsorption of supercritical CO 2 and molecular sieves according to claim 6, wherein the lifting ring is slidably connected to the inner wall of the sleeve, the inner protruding rod is fixedly clamped to the inner wall of the lifting ring, the end of the inner protruding rod extends into the cam groove, and the protruding block on the outer wall of the swivel is fixedly connected with the fixing block in the adsorption part through a bolt.
  8. 8. The apparatus for treating low caffeine by combining supercritical CO 2 with molecular sieve directional adsorption according to claim 7, wherein the upper end and the lower end of the tank are respectively clamped and fixed with a top cover and a bottom cover, the second motor is fixedly connected to the top surface of the top cover through bolts, a liquid return port is welded above the leftmost through hole, cleaning pipes are connected to the upper flanges of the two through holes on the right side, a communicating pipe is connected to the flange between the bottom surface of the bottom cover and the liquid outlet of the tank, and a drain pipe is connected to the lower flange of the two through holes on the right side.
  9. 9. The device for treating low caffeine by combining supercritical CO 2 with molecular sieve directional adsorption according to claim 8, wherein the fluid circulation mechanism comprises a pressurized gas tank, a peristaltic pump arranged between the pressurized gas tank and the extraction kettle, a return pipe and a liquid passing pipe, wherein the return pipe is connected with the upper end and the lower end of the pressurized gas tank in a flange mode, the other end of the liquid passing pipe is communicated with the liquid inlet end of the peristaltic pump, the liquid outlet end of the peristaltic pump is communicated with the liquid inlet of the kettle body through a pipeline, and the other end of the return pipe is communicated with the liquid return port of the top cover.
  10. 10. A method for treating low caffeine by supercritical CO 2 -molecular sieve-bound directional adsorption, using the supercritical CO 2 -molecular sieve-bound directional adsorption low caffeine treatment apparatus according to claim 9, comprising the steps of: S1, firstly, putting quantitative coffee beans into a kettle body through a feed inlet on a sealing plate at the top of an extraction kettle by an operator, fastening a sealing cover to form a pressure-bearing closed environment in the kettle body, simultaneously, filling food-grade CO 2 gas into a pressurized gas tank of a fluid circulation mechanism through an external gas source, and then starting a system cooling and pressurizing device to convert CO 2 into a supercritical fluid state with the temperature of 35-50 ℃ and the pressure of 100-250 bar; S2, starting a peristaltic pump, injecting supercritical CO 2 in a pressurized gas tank into the bottom of the kettle body from a liquid inlet through a liquid pipe, simultaneously starting a first motor to drive a packing auger to rotate in the filter cylinder, lifting coffee beans at the bottom of the kettle body to the top along the filter cylinder by the packing auger, scattering the coffee beans from the top end of the filter cylinder back to the bottom of the kettle, fully and dynamically contacting with supercritical CO2 flowing from bottom to top in the process, and efficiently extracting caffeine and part of flavor substances in the coffee beans into CO 2 fluid; S3, then, CO 2 fluid loaded with caffeine and flavor substances flows out from a liquid outlet, enters the treatment tank through the communicating pipe, and passes through an adsorption filter element currently positioned at the leftmost working station; meanwhile, the second motor is started to drive the rotating shaft to rotate forward at a low speed, the inner convex rod moves along the cam groove track and then drives the lifting ring to reciprocate up and down, and the rotary ring drives the adsorption part to reciprocate up and down in the through hole by a small extent, so that the channeling of the inner bed layer of the adsorption filter element is prevented by shaking, and the adsorption efficiency and capacity are improved; S4, returning the CO 2 fluid still rich in the flavor substances after passing through the adsorption filter element to the pressurized air tank through the return pipe from the liquid return port of the top cover to complete one cycle, and re-injecting the fluid into the kettle body through the peristaltic pump after re-pressurizing, wherein in the cycle, the CO 2 brings the flavor substances reserved after adsorption back to contact with the coffee beans, and the flavor substances can be adsorbed in pores on the surface of the coffee beans again, so that dynamic cycle and enrichment of flavor are formed, and the original flavor substances and saccharides in the coffee beans are reserved; S5, after the adsorption filter element positioned at the left working station adsorbs caffeine to be saturated, controlling the second motor to drive the rotating shaft to rotate reversely, and driving the ratchet wheel to push the pawl to drive the rotary drum to rotate by 120 degrees accurately; S6, introducing hot water with the temperature of 60-85 ℃ into a saturated adsorption filter element through a cleaning pipe at a first cleaning station, cleaning by utilizing the high solubility of caffeine in the hot water, discharging the dissolved caffeine wastewater from a drain pipe below to complete primary regeneration and caffeine recovery, subsequently controlling the rotary drum to rotate for 120 DEG again, moving an adsorption part for completing primary regeneration to a second cleaning station and below the other cleaning pipe, introducing heated dry nitrogen into the adsorption filter element through the cleaning pipe at the station, purging residual moisture, drying and activating the adsorbent, recovering the adsorption performance of the adsorbent, discharging moisture from the corresponding drain pipe, and finally completing deep regeneration of the adsorption filter element, wherein the caffeine adsorption operation can be carried out by putting the system again when the system is rotated to the working station next time; S7, repeating the steps S2 to S6 to realize full-automatic continuous operation of caffeine extraction, selective adsorption, flavor circulation and adsorbent alternate regeneration, stopping the first motor and the peristaltic pump when the caffeine content of the coffee beans in the kettle body is lower than a target threshold value, ending the dynamic extraction circulation, slowly releasing the pressure of the system, opening the bottom plate of the extraction kettle after the pressure is reduced to normal pressure, and taking out the coffee beans subjected to decaffeination.

Description

Low-caffeine treatment equipment and method by combining supercritical CO 2 with molecular sieve for directional adsorption Technical Field The invention relates to the technical field of coffee bean treatment, in particular to a low-caffeine treatment device and method by combining supercritical CO 2 with molecular sieve directional adsorption. Background The method has the key points that the method can mildly extract caffeine in coffee beans by utilizing the strong permeability of supercritical CO 2, and has the advantages that the process parameters are precisely controlled, so that CO 2 selectively carries caffeine molecules, and the caffeine molecules are directionally adsorbed and separated by a special molecular sieve, only the caffeine is captured by the specific pore diameter of the molecular sieve, and the coffee flavor precursor substances are completely reserved. The patent with the application number of CN202010342392.5 discloses a coffee component extraction and separation system which comprises an extraction tank, a first ejector, a second ejector, a first extraction material collection tank, a second extraction material collection tank, a third extraction material collection tank and a carbon dioxide cooling tank. By utilizing the suction force characteristic of high-pressure carbon dioxide fluid molecules to low-pressure carbon dioxide gas molecules, the high-pressure extraction fluid pressure energy is used as power to carry out jet suction, and the external power is not needed to enable the extraction material collecting tank to form a low-pressure state. However, the existing low caffeine treatment equipment adopts a traditional static soaking or percolating mass transfer mode, the contact area of coffee beans and solvent is small, the updating frequency is low, the single batch treatment time is long, the situation of partial excessive extraction or insufficient extraction is easy to occur, an adsorbent alternate regeneration system is lacking, automatic and precise switching of adsorption, cleaning and drying stations cannot be realized, the adsorbent needs to be stopped for regeneration after saturation, efficiency bottlenecks exist, the regeneration process is not complete enough, the deep efficient regeneration of the adsorbent is difficult to realize, and the adsorption efficiency and stability of long-term operation cannot be effectively ensured. In view of this, we propose a low caffeine processing apparatus and method combining supercritical CO 2 with molecular sieve directed adsorption. Disclosure of Invention The invention aims to provide a device and a method for treating low caffeine by combining supercritical CO 2 with molecular sieve directional adsorption, which construct a dynamic circulation extraction structure of coffee beans by arranging a packing auger and a filter cylinder which are driven by a motor in an extraction kettle so as to solve the problems in the background technology. In order to achieve the above object, in one aspect, the present invention provides the following technical solutions: A low-caffeine treatment device combining supercritical CO 2 with molecular sieve directional adsorption comprises an extraction kettle, and a fluid circulation mechanism and a treatment tank which are arranged on the left side and the right side of the extraction kettle; The extraction kettle comprises a kettle body for enabling CO 2 fluid to circulate from bottom to top and for placing coffee beans, a filter cylinder arranged in the center of the kettle body, and an auger arranged in the filter cylinder, wherein the auger lifts the coffee beans in the filter cylinder after rotating and falls back from the top end of the filter cylinder to dynamically contact with the CO 2 fluid; the treatment tank comprises a rotary drum, three adsorption filter elements which are regularly arranged in the rotary drum and selectively adsorb caffeine molecules, and a driving part for driving the rotary drum to rotate at fixed intervals; The drive part comprises a rotating shaft, a ratchet wheel sleeved on the outer wall of the rotating shaft, a plurality of pawls arranged on the outer side of the ratchet wheel and rotating on the inner wall of the circular groove on the top surface of the rotary drum, a lifting ring arranged below the ratchet wheel and an inner convex rod arranged on the inner wall of the lifting ring, wherein the outer wall of the rotating shaft is provided with a cam groove near the center, after the rotating shaft rotates positively, the inner convex rod drives the lifting ring to move up and down along the track of the cam groove, and drives three adsorption filter elements to synchronously move, and after the rotating shaft rotates reversely, the ratchet wheel props against the pawls to adjust the positions of the three adsorption filter elements by driving the rotary drum to rotate. In the technical scheme of the invention, the extraction kettle further comprises