A starch hydrolysis system and its hydrolysis method

Abstract

The invention discloses a starch hydrolysis system, which includes an ejector, a heating tank, a hydrolysis tank and a flash evaporation device; the heating tank is provided with a connected gas-liquid mixing cavity and a liquefaction coil, the flash evaporation device is arranged in the hydrolysis tank, and the hydrolysis tank is provided with a hydrolysis pipeline spirally surrounding the flash evaporation device; the ejector is connected to the gas-liquid mixing cavity, the gas-liquid mixing cavity is connected to a feeding pipeline filled with starch slurry, and the liquefaction coil is connected to the flash evaporation device through a pipeline; one end of the flash evaporation device is connected to the hydrolysis pipeline via a feeding pump, and the other end of the flash evaporation device is connected to the ejector. The starch hydrolysis system provided by the invention has simple equipment and small footprint, and the hydrolysis pipeline is arranged spirally around the flash evaporation device from bottom to top, so that the first-in-first-out of the hydrolysis liquid is realized, and the uniformity of hydrolysis is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of starch sugar production, and particularly relates to a starch hydrolysis system and a hydrolysis method thereof. Background Art

[0002] In the existing dual-enzyme starch hydrolysis to produce glucose production process, α-amylase is used to liquefy starch into paste or oligosaccharides, and this process is called hydrolysis. The hydrolysis process is specifically as follows: commercial starch is mixed with water to form a starch slurry of a certain concentration, hydrochloric acid or caustic soda is added to the starch slurry to adjust the pH value of the starch slurry, and then a certain amount of α-amylase is added to mix evenly, and then pumped to a steam jet heater, the starch milk temperature is instantly increased and maintained for a certain period of time, and then sent to a flash tank for flash cooling, and then sent to a hydrolysis laminar flow tank for hydrolysis by a centrifugal pump. In addition, in order to meet the time requirements for hydrolysis, multiple hydrolysis laminar flow tanks are usually installed, and each laminar flow tank is connected in series. The liquid flows in from the bottom of the first hydrolysis laminar flow tank and flows out from the top of the last hydrolysis laminar flow tank to complete the hydrolysis process.

[0003] The liquefied liquid that has completed hydrolysis is cooled, its pH value is adjusted, and after adding saccharifying enzyme in a certain proportion, it is sent to the saccharification tank to complete the conversion of dextrin or oligosaccharides into glucose.

[0004] In the above-mentioned existing hydrolysis methods, the main problems are that, first, due to the need to meet a certain hydrolysis time, a large number of hydrolysis laminar flow tanks are required, and it is impossible to ensure that the feed liquid in each laminar flow tank is first-in-first-out, resulting in inconsistent hydrolysis time and uneven hydrolysis. Second, the flash steam in the flash tank is directly discharged, resulting in waste of heat energy and equipment investment costs for flash steam treatment. Third, the entire hydrolysis process requires a large number of equipment and occupies a large area. Fourth, each device is connected by a pipeline, resulting in a large loss of feed liquid, a large resistance in the process of feed liquid transmission, an increase in the power cost, and an increase in the time and labor cost of cleaning the equipment and pipelines after hydrolysis.

[0005] In view of the above-mentioned problems, some of them have been improved in the patents disclosed. Patent CN204369870U discloses a laminar flow tank for starch sugar liquefaction, wherein the laminar flow tank is provided with a conical upper seal and a round-headed cylindrical lower seal, and the inner wall of the tube body of the laminar flow tank is provided with multiple parallel spiral grooves, and the outlets at both ends of the spiral grooves are sloped, and the lower part of the laminar flow tank is provided with a liquefied liquid inlet pipe, and the entry direction of the liquefied liquid inlet pipe is connected to the laminar flow tank along the tangent direction and the spiral direction of the spiral groove is consistent; the connection between the round-headed cylindrical lower seal and the laminar flow tank is a concave arc-shaped connector, and the arc-shaped connector is provided with a discharge port. The inlet liquid enters tangentially with the spiral groove, generating a spiral flow inside, thereby inducing the fluid in the entire laminar flow tank to generate a rotating flow. Although the spiral groove of the patent is conducive to the formation of a rotating flow of the liquid in the tank, there may still be mixed flow in the liquid in the tank, and it cannot be ensured that the liquid that enters the tank first will exit first.

[0006] Patent CN210314241U discloses a starch sugar liquefaction laminar flow tank, including a tank body, a lower head fixedly connected to the bottom of the tank body, a fixed plate fixedly connected to the outer side of the lower head, an upper head fixedly connected to the top of the tank body, a filter fixedly connected to the inside of the tank body, an electric telescopic rod fixedly installed on the top of the filter, and a first piston slidably connected to the inside of the tank body and above the electric telescopic rod. By setting pistons that move simultaneously, the liquid entering the laminar flow tank is first liquefied. After the liquefaction is completed, the liquid accumulates a certain amount, and the liquid level is sensed by the liquid level probe, and then the liquid inside the laminar flow tank is discharged, and the liquid is prevented from continuously entering. During the liquefaction, a spiral blade is used to ensure that the liquefied liquid is first in first out, and the last in and last out, and there is no mixing of the front and back liquids, so that the liquefaction effect is better. This patent uses an intermittent method to ensure that the liquid in the laminar flow tank is first in first out, but this method is discontinuous in production. When a large amount of starch hydrolysis is required, this method is less efficient. If a large amount of hydrolysis is satisfied by increasing the volume of the laminar flow tank, the resistance to the upward movement of the first piston will be greatly increased due to the increase in the tank body, and there is a risk of liquid leakage between the first piston and the inner wall of the laminar flow tank.

[0007] Patent CN203487158U discloses a starch sugar liquefaction laminar flow tank, which includes a tank body, an upper head and a lower head are connected to the upper and lower ends of the tank body respectively, the upper head is in the shape of a cone, the lower head is in the shape of an inverted cone, the top of the upper head is provided with a discharge port, the bottom of the lower head is provided with a feed port, and a spiral feeding device is provided in the lower head, the spiral feeding device includes a spiral blade, the spiral blade is spiral and extends from the top of the lower head to the bottom, the spiral radius of the spiral blade gradually decreases from the top of the lower head to the bottom of the lower head, and the spiral blade is welded to the inner wall surface of the lower head. The patent adopts the arrangement of spiral blades in the lower head to ensure that the liquid in the laminar flow tank will not gather at the bottom of the tank body, which is conducive to the rise of the liquid. However, since the upper part of the laminar flow tank is not provided with a spiral structure, the liquid rising to the upper area of ​​the tank body may still fall, so it is still impossible to completely ensure that the liquid in the laminar flow tank is first in, first out.

[0008] From the public patents that have been consulted, most of the problems of existing starch hydrolysis methods are improvements and solutions to the problem that the liquid in the hydrolysis laminar flow tank cannot ensure first-in-first-out, resulting in uneven hydrolysis, but at the same time, there are also some shortcomings of their own. And the solutions to other problems of existing starch hydrolysis methods are rarely involved. Summary of the invention

[0009] The object of the present invention is to provide a starch hydrolysis system and a hydrolysis method thereof, so as to solve the problems of heat waste in the existing hydrolysis system and method, and the problem that the liquid in the hydrolysis laminar flow tank cannot ensure first-in-first-out, resulting in uneven hydrolysis.

[0010] The purpose of the present invention is achieved through the following technical solutions:

[0011] A starch hydrolysis system, comprising an ejector, a heating tank, a hydrolysis tank and a flash evaporation device;

[0012] The heating tank is provided with a connected vapor-liquid mixing cavity and a liquefaction coil, the flash evaporation device is arranged in the hydrolysis tank, and a hydrolysis pipeline is arranged on the periphery of the flash evaporation device in a spiral manner from bottom to top;

[0013] The ejector is connected to a vapor-liquid mixing chamber, the vapor-liquid mixing chamber is connected to a feeding pipeline filled with starch slurry, and the liquefaction coil is connected to a flash evaporation device through a pipeline;

[0014] One end of the flash evaporation device is connected to the hydrolysis pipeline via a feed pump, and the other end of the flash evaporation device is connected to the ejector.

[0015] Furthermore, a bottom plate is provided between the gas-liquid mixing cavity and the liquefaction coil, the gas-liquid mixing cavity is located above the liquefaction coil, a liquid outlet is provided on the bottom plate, and a baffle is provided above the liquid outlet;

[0016] The liquid outlet is communicated with the liquefaction coil;

[0017] Preferably, the liquefaction coil is provided with three sections, and a controllable opening and closing valve is provided on the pipeline connecting each section with the flash evaporation device;

[0018] Preferably, the controllable opening and closing valve is a three-way valve.

[0019] Furthermore, the feeding pipeline is provided with a rotating nozzle at the outlet end in the gas-liquid mixing chamber;

[0020] Preferably, the outer wall of the liquefaction coil is provided with a pipe insulation layer, and the bottom of the heating tank is provided with a support column for supporting the tank body;

[0021] Preferably, a cleaning pipeline is provided on the feeding pipeline located outside the heating tank, and a sixth control valve is provided on the cleaning pipeline.

[0022] Furthermore, the flash evaporation device is provided with a liquid inlet, and a pressure reducing valve is provided on the pipeline connecting the liquefaction coil and the liquid inlet;

[0023] The height of the lowest point of the liquefaction coil is higher than the height of the liquid inlet;

[0024] Preferably, the liquid inlet is arranged at a position of 1 / 2 to 3 / 4 of the overall height of the flash evaporation device;

[0025] More preferably, the liquid inlet is arranged at 2 / 3 of the overall height of the flash evaporation device.

[0026] Furthermore, the flash evaporation device passes through the hydrolysis tank body, and the outer wall of the hydrolysis pipeline is provided with a pipeline insulation layer;

[0027] A check valve is provided on the pipeline connecting the flash evaporation device and the ejector, a liquid discharge port is provided at the bottom of the flash evaporation device, a feed pump is provided on the pipeline connecting the liquid discharge port and the hydrolysis pipeline, a liquid discharge pipe is provided on the pipeline connecting the feed pump and the hydrolysis pipeline, and a second control valve is provided on the liquid discharge pipe;

[0028] Preferably, the angle between the direction of the hydrolysis pipeline spiraling upward around the flash evaporation device and the horizontal line direction is 5°;

[0029] Preferably, the bottom of the flash evaporation device is a conical structure, and the drain port is arranged at the lowest point of the bottom of the flash evaporation device;

[0030] Preferably, an enzyme mixer for supplementing amylase is provided on the pipeline connecting the feed pump and the hydrolysis pipeline;

[0031] Preferably, the feed pump is a centrifugal pump.

[0032] Furthermore, a liquid outlet pipe is provided outside the hydrolysis tank, and the liquid outlet pipe is connected to the hydrolysis pipeline;

[0033] The liquid outlet pipe is provided with a branch pipeline for exhausting gas, and the branch pipeline is provided with a fourth control valve.

[0034] Furthermore, the ejector is arranged above the hydrolysis tank via a first support column, and a third support column for supporting the hydrolysis tank is arranged at the bottom of the hydrolysis tank;

[0035] The steam of the ejector enters the vapor-liquid mixing cavity of the heating tank through an ejection port, and the ejection port is arranged below the rotating ejector head;

[0036] Preferably, the injection port is arranged in the middle of the gas-liquid mixing cavity.

[0037] A starch hydrolysis method, according to any one of the above hydrolysis systems, comprises the following specific steps:

[0038] (a) The high-temperature steam in the ejector and the starch slurry in the feeding pipe enter the steam-liquid mixing chamber of the heating tank to heat the starch slurry, and the heated starch slurry enters the liquefaction coil;

[0039] (b) The starch slurry in the liquefaction coil enters the flash evaporation device to form a vapor phase and a liquid phase. The liquid phase enters the hydrolysis tank through the feed pump d to be hydrolyzed. After the hydrolysis is completed, it is discharged from the hydrolysis pipeline;

[0040] (c) The high-temperature vapor phase in the flash device enters the ejector and enters the heating tank together with the high-temperature steam in the ejector.

[0041] Furthermore, the starch slurry heated in step (a) is subjected to heat preservation for a specific section in the liquefaction coil.

[0042] If the slurry discharged from the hydrolysis pipeline in step (b) needs to be hydrolyzed again, the hydrolyzed slurry enters the vapor-liquid mixing zone of the heating tank through the feeding pipeline to undergo a second heating, flash evaporation and hydrolysis process.

[0043] Furthermore, the specific steps of starch hydrolysis also include a cleaning operation of the hydrolysis system:

[0044] (d) Open the sixth control valve, and introduce cleaning liquid to clean the heating tank, the flash evaporation device and the hydrolysis pipeline. The cleaning liquid is discharged through the branch pipeline of the liquid outlet pipe until the pipeline is clean. The beneficial effects of the present invention are:

[0045] The beneficial effects of the present invention are:

[0046] 1. The starch hydrolysis system provided by the present invention only requires a hydrolysis pipeline and related bottom drain valves and top exhaust valves for the hydrolysis part. Compared with the existing hydrolysis system which requires multiple laminar flow tanks, it reduces the investment in equipment, reduces the workload of operators, and reduces the problem of high probability of misoperation.

[0047] 2. The starch hydrolysis system provided by the present invention adopts a hydrolysis pipeline, which is arranged spirally upward around the flash evaporation device. On the one hand, the internal space of the hydrolysis tank is fully utilized to reduce the equipment footprint. On the other hand, the feed liquid is first in first out during the hydrolysis process, ensuring uniform hydrolysis.

[0048] 3. The starch hydrolysis system provided by the present invention allows the steam generated in the flash evaporation device to enter the ejector again, and then be used to heat the starch slurry in the heating tank, thereby avoiding heat loss and recycling heat, saving thermal energy.

[0049] 4. In the starch hydrolysis system provided by the present invention, the liquid in the liquefied coil is transferred by utilizing the pressure in the gas-liquid mixing chamber and the gravity of the liquid in the liquefied coil itself, and the compact design between each unit reduces the power cost generated by the transmission resistance of the liquid in the pipeline. In addition, the liquefied coil is provided with three sections to meet the insulation requirements of starch slurry of different volumes in the liquefied coil.

[0050] 5. The starch hydrolysis system provided by the present invention is also provided with a cleaning pipeline, which can fully clean the hydrolysis system, avoid clogging of the pipeline, and ensure the cleanliness of the pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A schematic structural diagram of the hydrolysis system of the present invention;

[0052] Figure 2 A schematic diagram of the positional relationship between the hydrolysis tank and the flash evaporation device in the hydrolysis tank of the present invention;

[0053] Figure 3 A schematic diagram of the section structure of the liquefied coil of the present invention;

[0054] Figure 4 A schematic diagram of the structure of the pipeline heat insulation layer of the outer wall of the hydrolysis pipeline of the present invention;

[0055] Figure 5 A schematic diagram of the structure of the pipe insulation layer on the outer wall of the liquefied coil of the present invention.

[0056] Figure numerals: 11, ejector; 12, heating tank; 13, hydrolysis tank; 14, flash evaporation device; 15, vapor-liquid mixing chamber; 16, liquefaction coil; 17, pressure reducing valve; 18, hydrolysis pipeline; 19, feed pump; 20, feeding pipe; 21, fixed surface; 111, steam inlet; 112, injection port; 141, check valve; 142, liquid discharge port; 143, first control valve; 144, liquid inlet; 151, baffle; 152, liquid outlet; 161, pipeline insulation layer; 162, first three-way valve; 163, second three-way valve; 164, third three-way valve; 181, Liquid discharge pipe; 182, second control valve; 183, liquid outlet pipe; 184, third control valve; 185, fourth control valve; 201, rotating nozzle; 202, fifth control valve; 203, cleaning pipeline; 204, sixth control valve; 211, first support column; 212, second support column; 213, third support column. DETAILED DESCRIPTION

[0057] In order to fully understand the beneficial effects of the sterilization of lime milk in the present technical solution, the following embodiments are listed for specific and detailed description.

[0058] Example 1

[0059] This embodiment provides a starch hydrolysis system, such as Figure 1 As shown, the hydrolysis system includes an ejector 11, a heating tank 12, a hydrolysis tank 13 and a flash evaporation device 14. The heating tank 12 is provided with a vapor-liquid mixing chamber 15 and a liquefaction coil 16. The vapor-liquid mixing chamber 15 is communicated with the ejector 11. The vapor-liquid mixing chamber 15 is communicated with a feeding pipe 20 filled with starch slurry. The liquefaction coil 16 is communicated with the flash evaporation device 14 through a pipeline. The flash evaporation device 14 is arranged in the hydrolysis tank 13. The flash evaporation device 14 is communicated with a hydrolysis pipeline 18 in the hydrolysis tank 13 through a pipeline. The flash evaporation device 14 is communicated with the ejector 11 through a pipeline.

[0060] The ejector 11 is installed above the hydrolysis tank 13 through the first support column 211. One end of the ejector 11 is provided with a steam inlet 111, and the other end of the ejector 11 is an ejection port 112. The ejection port 112 is opened in the vapor-liquid mixing chamber 15 of the heating tank 12. The steam in the ejector 11 ejects high-temperature steam to the vapor-liquid mixing chamber 15 in the heating tank 12 to heat the starch slurry entering the vapor-liquid mixing chamber 15. A check valve 141 is provided on the pipeline connecting the ejector 11 and the flash evaporation device 14. The check valve 141 is used to prevent the steam in the ejector 11 from entering the flash evaporation device, but the steam generated in the flash evaporation device 14 can enter the ejector 11 through the opening of the check valve 141.

[0061] The vapor-liquid mixing cavity 15 and the liquefaction coil 16 in the tank body of the heating tank 12 are separated by a bottom plate, and a liquid outlet 152 is provided on the bottom plate. The liquid outlet 152 is close to the inner wall of the heating tank 12, and the liquid outlet 152 is communicated with the liquefaction coil 16. The feeding pipe 20 is provided with a rotating nozzle 201 at the outlet end in the vapor-liquid mixing cavity 15. The liquid outlet 152 is preferably arranged in a direction away from the injection port 112 and the rotating nozzle 201. A baffle 151 is provided above the liquid outlet 152, and the baffle 151 is used to prevent the starch slurry sprayed by the rotating nozzle 201 from falling into the liquid outlet 152 without being heated and mixed by high-temperature steam.

[0062] The rotating nozzle 201 sprays the starch slurry into the gas-liquid mixing chamber 15 in a shower shape, which is conducive to the high-temperature steam ejected from the ejector 11 and the incoming starch slurry to be fully mixed and heated more evenly. The rotating nozzle 201 is located above the injection port 112, and the rotating nozzle 201 is located in the area between the center line of the gas-liquid mixing chamber 15 and the injection port 112, which is conducive to the starch slurry being quickly mixed with the high-temperature steam ejected from the injection port 112 after being ejected from the rotating nozzle 201.

[0063] The starch slurry after being heated and mixed by high-temperature steam is discharged to the liquefaction coil 16 through the liquid outlet 152. The outer wall of the liquefaction coil 16 is provided with a pipe insulation layer 161 for heat preservation. The total length of the liquefaction coil 16 is set according to the process time requirement for maintaining heat preservation. The liquefaction coil 16 is arranged into a plurality of sections. A three-way valve is installed between each section and between each section and the pipe connecting the flash evaporation device 14. By controlling the opening and closing of the three-way valve, the liquefaction coil 16 of different sections is selected according to different process time requirements.

[0064] like Figure 3 As shown, in this embodiment, the liquefaction coil 16 is divided into three use sections:

[0065] The liquefaction coil 16 is divided into a first section, a second section and a third section from top to bottom, each section is connected to the liquid inlet 144 of the flash evaporation device 14 through a pipeline, and a first three-way valve 162, a second three-way valve 163 and a third three-way valve 164 are respectively provided on the connected pipelines. The first three-way valve 162, the second three-way valve 163 and the third three-way valve 164 execute opening and closing instructions according to a set program through a DCS control system to realize the opening or closing of the valves. The first three-way valve 162 controls the opening and closing of the first section, the second section and the pipeline leading to the liquid inlet 144 of the flash evaporation device 14. The second three-way valve 163 controls the opening and closing of the second section, the third section and the pipeline leading to the liquid inlet 144 of the flash evaporation device 14. The third three-way valve 164 controls the opening and closing of the first section, the third section and the pipeline leading to the liquid inlet 144 of the flash evaporation device 14.

[0066] When the first section of the liquefied coil 16 is used, the first three-way valve 162 is opened to the passage leading to the liquid inlet 144 of the flash device 14, and the valves in other directions are closed to ensure that the liquid in the liquefied coil 16 of the first section is directly discharged into the flash device 14, and does not enter the liquefied coil 16 of the second section and the third section.

[0067] When the first section and the second section of the liquefied coil 16 are in use, open the first three-way valve 162 in the direction of the second section, and at the same time open the passage of the second three-way valve 162 leading to the liquid inlet 144 of the flash device 14, and close the valves in other directions to ensure that the liquid in the liquefied coil 16 of the first section and the second section is directly discharged into the flash device 14 without entering the liquefied coil 16 of the third section.

[0068] When the entire liquefaction coil 16 is used, open the first three-way valve 162 in the direction of the second section, open the second three-way valve 163 in the direction of the third section, and at the same time open the passage of the third three-way valve 163 leading to the liquid inlet 144 of the flash evaporation device 14, and close the valves in other directions to ensure that all the heated liquid passes through the liquefaction coil 16 and is discharged into the flash evaporation device 14.

[0069] The bottom of the heating tank 12 is provided with a third supporting column 213 for supporting the tank body.

[0070] The lowest point of the liquefied coil 16 is higher than the height of the liquid inlet 144 of the flash evaporation device 14, and the flow direction of the slurry at the lowest point of the liquefied coil 16 to the liquid inlet 144 forms an angle of 5° with the horizontal line. In this embodiment, the height of the liquid inlet 144 is set in the middle of the flash evaporation device 14, ensuring that the liquid in the liquefied coil 16 can enter the flash evaporation device 14 through the liquid inlet 144 by itself through the pressure in the gas-liquid mixing cavity 15 and the gravity of the liquid in the liquefied coil 16.

[0071] A pressure reducing valve 17 is provided on the pipeline connecting the liquefaction coil 16 and the liquid inlet 144 of the flash evaporation device 14. The starch slurry enters the flash evaporation device 14 after being decompressed by the pressure reducing valve 17. Due to the reduction in pressure, the high-temperature liquid transmitted to the flash evaporation device 14 through the liquefaction coil 16 suddenly changes its boiling point, and the slurry quickly forms a vapor and liquid two-phase. The liquid flows to the bottom of the flash evaporation device 14, and the vapor phase moves upward in the flash evaporation device 14, opening the check valve 141, and the vapor phase enters the ejector 11, and enters the vapor-liquid mixing chamber 15 again together with the high-temperature steam entering from the steam inlet 111 of the ejector 11 to heat the starch slurry, thereby realizing the reuse of the flash steam thermal energy.

[0072] When high-temperature steam enters the ejector 11 at high speed from the steam inlet 111 of the ejector 11 , the vapor phase in the flash device 14 enters the ejector 11 . At this time, negative pressure is formed in the inlet area where the vapor phase enters the ejector 11 , which is further conducive to the vapor phase entering the ejector 11 .

[0073] The liquid phase in the flash evaporation device 14 flows to the bottom of the flash evaporation device 14, and the bottom of the flash evaporation device 14 is a conical structure. The discharge port 142 of the flash evaporation device 14 is set at the lowest point of the bottom, so that the liquid can completely reach the discharge port 142. The discharge port 142 is connected to the hydrolysis pipeline 18 through a pipeline, and a feed pump 19 and a discharge pipe 181 are provided on the connected pipeline, and a second control valve 182 is provided on the discharge pipe 181. When the starch hydrolysis process is normally carried out, the second control valve 182 is in a normally closed state. When the equipment is maintained, the second control valve 182 is opened to discharge the residual liquid or cleaning liquid in the flash evaporation device 14.

[0074] like Figure 2 The top view of the hydrolysis tank shown in the figure shows that the flash evaporation device 14 is arranged throughout the hydrolysis tank 13, and the hydrolysis pipeline 18 is installed in the hydrolysis tank 13 in a spiral upward manner around the flash evaporation device 14. The outer wall of the hydrolysis pipeline 18 is provided with a pipeline insulation layer 161 for maintaining the liquid temperature in the hydrolysis pipeline 18.

[0075] The diameter of the hydrolysis pipeline 18, the total length of the pipeline and the flow rate of the slurry in the pipeline are determined according to the specific process requirements. The total length of the hydrolysis pipeline 18 can be achieved by controlling the diameter, height and angle between the center line of the hydrolysis pipeline 18 and the horizontal center line of the hydrolysis tank 13. Increasing the inner diameter of the spiral structure of the hydrolysis pipeline 18, increasing the height of the hydrolysis tank 13, and reducing the angle between the center line of the hydrolysis pipeline 18 and the horizontal line can increase the distance that the liquid flows in the hydrolysis pipeline 18, thereby controlling the hydrolysis time.

[0076] When the length of the hydrolysis pipeline 18 is constant, in order to meet a certain output rate, this can be achieved by controlling the size of the diameter of the hydrolysis pipeline 18 .

[0077] The diameter and height of the hydrolysis tank 13, the caliber of the hydrolysis pipeline 18, and the spacing between the upper and lower adjacent pipelines need to be determined in advance according to the requirements of the process conditions before production. When the hydrolysis time still needs to be adjusted during production and use, it can be achieved by controlling the flow rate of the liquid in the hydrolysis pipeline 18.

[0078] The hydrolysis pipeline 18 can control the hydrolysis time of the slurry through different sections, which can be achieved by setting controllable opening and closing valves, such as three-way valves, between different sections and between the sections and the liquid outlet pipe 183 outside the hydrolysis tank 13. When it is necessary to use the hydrolysis pipeline of different sections, the valve of the corresponding section is opened to allow the slurry to flow out of the liquid outlet pipe 183.

[0079] In order to increase the stability of the hydrolysis pipeline 18 , support structures (not shown in the drawings) may be provided in sections and fixed on the inner wall of the hydrolysis tank 13 .

[0080] An enzyme mixer (not shown in the drawings) can be added to the pipeline between the feed pump 19 and the hydrolysis pipeline 18 to supplement amylase before hydrolysis. The diameter of the hydrolysis pipeline 18 is consistent with the diameter of the outlet of the feed pump 19. The liquid fed into the hydrolysis pipeline 18 by the feed pump 19 will continue to push the liquid in the hydrolysis pipeline 18 to flow upward, avoiding the disturbance of the liquid when a small diameter is fed into a large diameter.

[0081] Example 2

[0082] The height of the liquid inlet 144 in this embodiment is set at 2 / 3 of the height of the flash evaporation device 14, the feed pump 19 is a centrifugal pump, and the upward inclination angle of the hydrolysis pipeline 18, that is, the angle between the center line of the liquid flow in the pipeline and the horizontal direction is 5°. The arrangement and connection relationship of other devices are the same as in Example 1.

[0083] Example 3

[0084] This embodiment provides a hydrolysis method, and the specific hydrolysis method is as follows:

[0085] (a) High-temperature steam enters the ejector 11 at high speed from the steam inlet 111 of the ejector 11 and is sprayed into the vapor-liquid mixing chamber 15 of the heating tank 12 through the injection port 112. At this time, the vapor-liquid mixing chamber 15 is filled with high-temperature steam at a temperature of 105°C to 108°C.

[0086] The starch slurry obtained through the previous process enters the gas-liquid mixing chamber 15 of the heating tank 12 through the feeding pipe 20. Under the action of the rotating nozzle 201, the starch slurry is sprayed into the gas-liquid mixing chamber 15. When the starch slurry is sprayed from the rotating nozzle 201, high-temperature steam is simultaneously sprayed from the injection port 112 of the ejector 11. The starch slurry and the high-temperature steam are fully mixed in the gas-liquid mixing chamber 15, and the starch slurry is heated to 105°C~108°C by the high-temperature steam.

[0087] As high-temperature steam is continuously injected into the gas-liquid mixing chamber 15 , the pressure is continuously increased, and the starch slurry heated by high temperature enters the liquefaction coil 16 from the liquid outlet 152 on the bottom plate.

[0088] (b) The pipe insulation layer 161 disposed on the outer wall of the liquefaction coil 16 maintains the temperature of the slurry in the liquefaction coil 16. The high-temperature slurry in the liquefaction coil 16 is maintained in the liquefaction coil 16 for 6 minutes, which is conducive to the complete gelatinization of starch.

[0089] After the slurry in the liquefied coil 16 is maintained for 6 minutes, it is decompressed by the pressure reducing valve 17 and enters the flash evaporation device 14 from the liquid inlet 144 in the middle of the flash evaporation device 14.

[0090] After the sudden pressure change, the slurry undergoes gas-liquid phase separation in the flash device 14 .

[0091] The temperature of the liquid separated in the flash evaporation device 14 is between 95°C and 98°C, and it flows to the bottom of the flash evaporation device 14 and is discharged from a liquid discharge port 142 disposed at the bottom of the flash evaporation device 14. The liquid is pressurized by a feed pump 19 and then transported to a hydrolysis pipeline 18.

[0092] The flow rate and pressure of the feed pump 19 are controlled, and the liquid slowly rises along the spiral rising pipeline in the hydrolysis pipeline 18. The outer wall of the hydrolysis pipeline 18 is provided with a pipeline insulation layer 161 to maintain the temperature of the liquid in the pipeline. During the rising process of the liquid in the hydrolysis pipeline 18, the hydrolysis is continuously performed for 120 minutes under the condition of maintaining a temperature of 95°C to 98°C.

[0093] When the liquefied liquid rises to the top of the hydrolysis pipe 18, the hydrolysis process is completed, and the liquid is discharged from the liquid outlet pipe 183 arranged at the upper part of the hydrolysis tank 13 to the downstream process, thereby completing the hydrolysis process of the starch.

[0094] (c) The separated gas phase is discharged from the top outlet of the flash evaporator 14 into the ejector 11 and mixed with the high-temperature steam entering from the steam inlet 111 of the ejector 11 and then ejected from the ejection port 112 to heat the starch slurry.

[0095] When secondary hydrolysis is required:

[0096] The hydrolyzed liquid discharged from the liquid outlet pipe 183 continues to enter the heating tank through the feeding pipe 20, and the operating steps shown in Example 3 are repeated. At the same time, an enzyme mixer for supplementing amylase is added to the pipe between the feed pump 19 and the hydrolysis pipe 18. Finally, the liquid with secondary water structure is discharged from the liquid outlet pipe 183 and sent to the downstream process.

[0097] Example 4

[0098] After the hydrolysis is completed, the entire hydrolysis system needs to be cleaned. The specific operations are as follows:

[0099] The ejector 11 is stopped, and the fifth control valve 202 on the feeding pipe 20 is closed to stop feeding the starch slurry. The liquefied liquid in the liquefaction coil 16, the flash evaporation device 14 and the hydrolysis pipeline 18 is discharged by the feed pump 19.

[0100] Stop the feed pump 19, close the third control valve 184 on the liquid outlet pipe 183, open the fourth control valve 185 on the branch line of the liquid outlet pipe 183, and discharge the gas in the hydrolysis pipeline 18. Then open the second control valve 182 on the liquid discharge pipe 181 below the hydrolysis pipeline 18 to discharge the residual liquid in the hydrolysis pipeline 18.

[0101] The first control valve 143 on the branch pipeline below the liquid discharge port 142 at the bottom of the flash evaporation device 14 is opened to discharge the residual liquid in the flash evaporation device 14 .

[0102] After the residual liquid in each of the above units is drained, the fifth control valve 202 is kept closed, the opening and closing states of other control valves during the hydrolysis process are restored, and the sixth control valve 204 on the cleaning pipeline 203 is opened.

[0103] Water or cleaning liquid is injected into the gas-liquid mixing chamber 15 through the cleaning pipeline 203, and the cleaning liquid is used to clean the device according to the flow route of the starch slurry and the liquefied liquid during the hydrolysis process.

[0104] During cleaning, the ejector 11 can be turned on to eject high-temperature steam into the gas-liquid mixing chamber 15, and the cleaning liquid introduced into the gas-liquid mixing chamber 15 can be heated before cleaning the device. The high-temperature cleaning liquid has a more efficient cleaning effect on the device.

[0105] After cleaning is completed, the cleaning liquid remaining in each unit is discharged by opening and closing the control valve in the same manner as the above-mentioned operation of discharging the residual liquefied liquid.

[0106] After draining the remaining cleaning liquid, restore the control valve status of each unit to the status during the hydrolysis process, waiting for the next starch hydrolysis.

[0107] It should be noted that, in the present invention, terms such as "upper", "lower", "one end", "the other end", "bottom" and "top" are all descriptions based on the positional relationships in the drawings of the present invention specification, and are not intended to limit the scope of implementation of the present invention. Changes or adjustments in their relative relationships, without substantially changing the technical content, should also be regarded as the scope of implementation of the present invention.

[0108] The above description is a detailed description of the preferred feasible embodiments of the present invention, but the embodiments are not intended to limit the scope of the patent application of the present invention. All equivalent changes or modified changes completed under the technical spirit suggested by the present invention should fall within the patent scope covered by the present invention.

Claims

1. A starch hydrolysis system, characterized in that: The hydrolysis system comprises an ejector (11), a heating tank (12), a hydrolysis tank (13) and a flash evaporation device (14); The heating tank (12) is provided with a connected vapor-liquid mixing cavity (15) and a liquefaction coil (16); the flash evaporation device (14) is arranged in the hydrolysis tank (13); and a hydrolysis pipeline (18) is arranged on the outer periphery of the flash evaporation device (14) in a spiral manner from bottom to top; The ejector (11) is in communication with a vapor-liquid mixing chamber (15), the vapor-liquid mixing chamber (15) is in communication with a feeding pipeline (20) filled with starch slurry, and the liquefaction coil (16) is in communication with a flash evaporation device (14) via a pipeline; One end of the flash evaporation device (14) is connected to the hydrolysis pipeline (18) via a feed pump (19), and the other end of the flash evaporation device (14) is connected to the ejector (11); A bottom plate is provided between the gas-liquid mixing cavity (15) and the liquefaction coil (16); the gas-liquid mixing cavity (15) is located above the liquefaction coil (16); a liquid outlet (152) is provided on the bottom plate; a baffle (151) is provided above the liquid outlet (152); and the liquid outlet (152) is communicated with the liquefaction coil (16); The feeding pipe (20) is provided with a rotating nozzle (201) at the outlet end located in the gas-liquid mixing chamber (15); The flash evaporation device (14) is provided with a liquid inlet (144), a pressure reducing valve (17) is provided on a pipeline connecting the outlet of the liquefaction coil (16) and the liquid inlet (144), and the height of the lowest point of the liquefaction coil (16) is higher than the height of the liquid inlet (144); The flash evaporation device (14) passes through the central part of the hydrolysis tank (13), and the outer wall of the hydrolysis pipeline (18) is provided with a pipeline heat insulation layer (161); A check valve (141) is provided on the pipeline connecting the flash evaporation device (14) and the ejector (11); a liquid discharge port (142) is provided at the bottom of the flash evaporation device (14); a feed pump (19) is provided on the pipeline connecting the liquid discharge port (142) and the hydrolysis pipeline (18); a liquid discharge pipe (181) is provided on the pipeline connecting the feed pump (19) and the hydrolysis pipeline (18); and a second control valve (182) is provided on the pipeline of the liquid discharge pipe (181); The hydrolysis tank (13) is provided with a liquid outlet pipe (183) outside, the liquid outlet pipe (183) is in communication with the hydrolysis pipeline (18), a branch pipeline for exhausting gas is provided on the liquid outlet pipe (183), and a fourth control valve (185) is provided on the branch pipeline; The ejector (11) is arranged above the hydrolysis tank (13) via a first support column (211), and a third support column (213) for supporting the hydrolysis tank (13) is provided at the bottom of the hydrolysis tank (13); One end of the ejector (11) is provided with a steam inlet (111), and the other end of the ejector (11) is an ejection port (112); the steam of the ejector (11) enters the steam-liquid mixing cavity (15) of the heating tank (12) through the ejection port (112); the ejection port (112) is arranged below the rotating ejector head (201); The liquefaction coil (16) is provided with three sections, and a controllable valve is provided on the pipeline connecting each section and the flash evaporation device (14); The feeding pipeline (20) is provided with a cleaning pipeline (203) on the pipeline located outside the heating tank (12), and the cleaning pipeline (203) is provided with a sixth control valve (204).

2. The hydrolysis system according to claim 1, characterized in that: The controllable opening and closing valve is a three-way valve.

3. The hydrolysis system according to claim 1, characterized in that: The outer wall of the liquefaction coil (16) is provided with a pipeline heat insulation layer (161), and the bottom of the heating tank (12) is provided with a support column for supporting the tank body.

4. The hydrolysis system according to claim 1, characterized in that: The liquid inlet (144) is arranged at a position between 1 / 2 and 3 / 4 of the overall height of the flash evaporation device (14).

5. The hydrolysis system according to claim 4, characterized in that: The liquid inlet (144) is arranged at a position 2 / 3 of the overall height of the flash evaporation device (14).

6. The hydrolysis system according to claim 1, characterized in that: The angle between the hydrolysis pipeline (18) spiraling upward around the flash evaporation device (14) and the horizontal line direction is 5°.

7. The hydrolysis system according to claim 1, characterized in that: The bottom of the flash evaporation device (14) is a conical structure, and the liquid discharge port (142) is arranged at the lowest point of the bottom of the flash evaporation device (14).

8. The hydrolysis system according to claim 1, characterized in that: An enzyme mixer for supplementing amylase is provided on the pipeline connecting the feed pump (19) and the hydrolysis pipeline (18).

9. The hydrolysis system according to claim 1, characterized in that: The feed pump (19) is a centrifugal pump.

10. The hydrolysis system according to claim 1, characterized in that: The injection port (112) is arranged in the middle of the gas-liquid mixing cavity (15).

11. A starch hydrolysis method, using the starch hydrolysis system according to claim 1 for hydrolysis, characterized in that: The specific steps of starch hydrolysis are: (a) high-temperature steam in the ejector (11) and starch slurry in the feeding pipe (20) enter the steam-liquid mixing chamber (15) of the heating tank (12) to heat the starch slurry, and the heated starch slurry enters the liquefaction coil (16); (b) the starch slurry in the liquefaction coil (16) enters the flash evaporation device (14) to form a vapor phase and a liquid phase, and the liquid phase enters the hydrolysis pipeline (18) through the feed pump (19) for hydrolysis, and is discharged from the hydrolysis pipeline (18) after the hydrolysis is completed; (c) The high-temperature vapor phase in the flash device (14) enters the ejector (11) and enters the heating tank (12) together with the high-temperature steam in the ejector (11).

12. The hydrolysis method according to claim 11, characterized in that The starch slurry heated in step (a) is subjected to heat preservation for a specific section in the liquefaction coil (16) according to the required heat preservation time; If the slurry discharged from the hydrolysis pipeline (18) in step (b) needs to be hydrolyzed again, the hydrolyzed slurry enters the vapor-liquid mixing chamber (15) of the heating tank (12) again through the feeding pipeline (20) to undergo a second heating, flash evaporation and hydrolysis process.

13. The hydrolysis method according to claim 11, characterized in that The specific steps of starch hydrolysis also include cleaning operation of the hydrolysis system: (d) The cleaning liquid enters the heating tank (12), the flash evaporation device (14) and the hydrolysis pipeline (18) through the cleaning pipeline (203) to clean the system equipment. The cleaned liquid is discharged through the liquid outlet pipe (183) until the pipeline is clean.

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