Environmentally friendly starch saccharification system and method

Abstract

The invention provides a starch saccharification system, comprising a pulp mixing tank, a three-stage heat exchanger, a two-stage steam jet heater, a laminar hydrolysis tank, a saccharification tank, an evaporation concentration unit and a control unit; the discharge port of the pulp mixing tank is connected to a first cold fluid feed port, the first hot fluid discharge port is connected to a first steam jet heater, the discharge port of the first steam jet heater is connected to a second hot fluid feed port, the second cold fluid discharge port is connected to a laminar hydrolysis tank, the discharge port of the laminar hydrolysis tank is connected to a third hot fluid feed port, and the third cold fluid discharge port is connected to the first feed port of the saccharification tank; the first discharge port of the saccharification tank is connected to the second cold fluid feed port, and the second hot fluid discharge port is connected to the first hot fluid feed port; the first cold fluid discharge port is connected to the third cold fluid feed port, and the third hot fluid discharge port is connected to the feed port of the evaporation concentration unit; the second discharge port of the saccharification tank is connected to the second steam jet heater, and the discharge port of the second steam jet heater is connected to the evaporation concentration unit.

Description

Technical Field

[0001] The present invention relates to the field of biological fermentation technology, and more specifically, to an environmentally friendly starch saccharification system and method. Background Art

[0002] At present, in the process of producing starch sugar by biological fermentation, starch is first added with water to form starch milk at 30°C, and amylase is added and sent to the steam jet heater by a centrifugal pump to raise the temperature of the starch milk to 105-108°C, and then maintained for about 6 minutes to enter the flash tank for flash evaporation. After the flash evaporation, the temperature drops to 95-98°C, and it is pumped into the laminar flow liquefaction tank for hydrolysis for 120 minutes. After the hydrolysis, the temperature of the liquefied liquid is still at 95-98°C. Before entering the saccharification process, the temperature needs to be reduced to 60-62°C, and then hydrochloric acid is added to adjust the pH value, and then saccharification is performed after adding saccharifying enzyme. When the liquefied liquid is cooled from 98°C to 62°C, a large amount of heat energy will be released. The usual practice is to use a circulating cooling tower to exchange heat with the liquefied liquid with circulating cooling water, and the circulating water enters the cooling tower for cooling after the temperature rises. In this process, in order to achieve the cooling of the liquefied liquid, additional circulating water equipment is required, which increases the cost of production and operation.

[0003] Patent CN101736059B discloses a method for recovering waste heat during the processing of starchy raw materials. After the starchy liquefied liquid is boiled and liquefied through laminar flow insulation, the material is discharged and vacuumed and cooled to obtain cooled starchy liquefied liquid. The secondary steam obtained through vacuuming is passed through a heat exchange device to recover waste heat and condensed water. The present invention also provides special equipment for this method. This method not only achieves the recycling and comprehensive utilization of waste heat during the saccharification of starchy raw materials, but also reduces the demand for cooling water. However, this patent increases the investment in circulating cooling water and the operating costs of circulating cooling water.

[0004] Patent CN206361673U discloses a flash evaporation waste heat recovery system in a starch sugar production process, including a secondary flash evaporation tank, a tertiary flash evaporation tank, and a first effect body, a second effect body, a third effect body, and a fourth effect body connected in series in sequence. The feed is transported to the discharge flash evaporation tank in reverse through each effect body through a discharge pump through a feed pipe, and each effect body includes a heating shell, a preheater, a vapor-liquid separator, and a delivery pump. The steam outlet of each vapor-liquid separator is connected to the heating shell of the latter effect body. The flash steam of the secondary flash evaporation, the tertiary flash evaporation, and the discharge flash evaporation is collected and recovered to the first effect body, the third effect body, and the fourth effect body through their respective steam flow regulating valves. Compared with the prior art, the flash evaporation waste heat recovery system described in the utility model improves the waste heat utilization efficiency in the starch sugar production process, reduces the amount of raw steam, saves costs, and stably realizes the saccharification cooling after the secondary injection, ensures the continuous secondary injection, and improves the liquefaction quality. However, the patent uses multiple flash evaporation equipment, which increases the investment cost of multiple flash evaporation equipment and tail gas recovery equipment.

[0005] It can be seen that the existing technology for heat recovery in the starch sugar production process needs to utilize the heat recycling of flash evaporation. Starch milk is heated by steam injection, and flash evaporation is required for cooling after injection. The flash evaporation process releases a large amount of high-temperature saturated steam. These steams carry a large amount of heat energy and are released into the atmosphere, which not only causes energy waste but also pollutes the environment.

[0006] In view of this, the present invention is proposed. Summary of the invention

[0007] In order to solve the problem that a large amount of heat energy generated in the existing process is directly discharged into the atmosphere, causing energy waste, the present invention utilizes the dilute sugar solution produced in the process as an intermediate heat exchange medium, and recovers the heat energy in the production process to the maximum extent through three-stage heat exchange. It also does not require practical flash evaporation equipment, thereby reducing the overall energy consumption of the system and the investment cost of the equipment.

[0008] In order to achieve the above effects, the basic concept of the technical solution of the present invention is as follows:

[0009] An environmentally friendly starch saccharification system comprises a slurry mixing tank, a first heat exchanger, a second heat exchanger, a third heat exchanger, a first steam jet heater and a second steam jet heater provided with a steam drum, a laminar hydrolysis tank, a saccharification tank, an evaporation concentration unit and a control unit;

[0010] The discharge port of the slurry mixing tank is connected to the first cold fluid feed port of the first heat exchanger, the first hot fluid discharge port of the first heat exchanger is connected to the first steam injection heater, the discharge port of the first steam injection heater is connected to the second hot fluid feed port of the second heat exchanger, the second cold fluid discharge port of the second heat exchanger is connected to the laminar hydrolysis tank, the discharge port of the laminar hydrolysis tank is connected to the third hot fluid feed port of the third heat exchanger, and the third cold fluid discharge port of the third heat exchanger is connected to the first feed port of the saccharification tank;

[0011] The first discharge port of the saccharification tank is connected to the second cold fluid feed port of the second heat exchanger, and the second hot fluid discharge port of the second heat exchanger is connected to the first hot fluid feed port of the first heat exchanger; the first cold fluid discharge port of the first heat exchanger is connected to the third cold fluid feed port of the third heat exchanger, and the third hot fluid discharge port of the third heat exchanger is connected to the feed port of the evaporation concentration unit;

[0012] The second discharge port of the saccharification tank is connected to the second steam jet heater, and the discharge port of the second steam jet heater is connected to the evaporation concentration unit;

[0013] The control unit controls the working states of the pulp mixing tank, the first heat exchanger, the second heat exchanger, the third heat exchanger, the first steam injection heater, the second steam injection heater, the laminar hydrolysis tank, the saccharification tank, the evaporation concentration unit and the auxiliary components arranged on the connecting pipelines therebetween.

[0014] An embodiment of the present invention provides an environmentally friendly starch saccharification system, wherein the auxiliary components include a pump, a solenoid valve, and a temperature measuring device.

[0015] An embodiment of the present invention provides an environmentally friendly starch saccharification system, wherein a first pump is provided at the discharge port of a slurry mixing tank, and the discharge port of the first pump is connected to a first cold fluid feed port of a first heat exchanger.

[0016] An embodiment of the present invention provides an environmentally friendly starch saccharification system, wherein the discharge port of a slurry mixing tank, the first cold fluid discharge port and the first hot fluid discharge port of a first heat exchanger, the discharge port of a first steam jet heater, the second hot fluid discharge port and the second cold fluid discharge port of a second heat exchanger, the third hot fluid discharge port and the third cold fluid discharge port of a third heat exchanger, the first feed port and the second discharge port of a saccharification tank, and the discharge port of the second steam jet heater are respectively equipped with temperature measuring devices for detecting the temperatures of each feed port and discharge port.

[0017] An embodiment of the present invention provides an environmentally friendly starch saccharification system, wherein the discharge port of a slurry mixing tank, the first cold fluid discharge port and the first hot fluid discharge port of a first heat exchanger, the discharge port of a first steam jet heater, the second hot fluid discharge port and the second cold fluid discharge port of a second heat exchanger, the third hot fluid discharge port and the third cold fluid discharge port of a third heat exchanger, the first feed port and the second discharge port of a saccharification tank, and the discharge port of the second steam jet heater are respectively provided with solenoid valves that can be controlled to open and close to control the transportation of materials at the corresponding feed and discharge ports.

[0018] The present invention further provides a starch saccharification method, which is run in the environmentally friendly starch saccharification system described in any one of the above contents.

[0019] As an implementation mode, when the environmentally friendly starch saccharification system is just started, the first heat exchanger, the second heat exchanger and the third heat exchanger are closed, and the starch is slurried in the slurry mixing tank and then transported to the first steam jet heater to be heated to 108°C, then naturally cooled to 98°C and transported to the laminar hydrolysis tank for hydrolysis, then naturally cooled to 60°C again and transported to the saccharification tank for saccharification. When the temperature in the saccharification tank drops to 65°C, a sufficient amount of dilute sugar liquid is collected and used as a heat exchange medium for subsequent processes.

[0020] As an implementation method, after there is dilute sugar liquid that can be used as a heat exchange medium in the starch saccharification system, the starch slurry that has completed slurry adjustment enters the first heat exchanger through the first cold fluid feed port, and at the same time, the 65°C dilute sugar liquid enters the first heat exchanger through the first hot fluid feed port to perform countercurrent heat exchange with the 30°C starch slurry;

[0021] After heat exchange, the 52°C starch emulsion enters the first steam jet heater through the first hot fluid outlet and is heated to 108°C, and then enters the second heat exchanger through the second hot fluid feed port. At the same time, the 55°C dilute sugar liquid enters the second heat exchanger through the second cold fluid feed port. The 108°C liquefied liquid exchanges heat with the 55°C dilute sugar and is cooled to 98°C, and the dilute sugar liquid is heated to 65°C. The 98°C liquefied liquid is transported to the laminar hydrolysis tank through the second cold fluid outlet, and the 65°C dilute sugar liquid is transported from the second hot fluid outlet to the first hot fluid feed port to heat exchange and heat the 30°C starch emulsion.

[0022] The 98°C liquefied liquid after hydrolysis in the laminar flow hydrolysis tank enters the third heat exchanger through the third hot fluid feed port, and at the same time, the 43°C dilute sugar liquid output through the first cold fluid discharge port enters the third heat exchanger through the third cold fluid feed port. The 98°C liquefied liquid and the 43°C dilute sugar liquid undergo countercurrent heat exchange to obtain a 60°C liquefied liquid. The dilute sugar liquid after heat exchange enters the evaporation and concentration unit for evaporation and concentration.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. In the whole process of starch saccharification liquid production, the present invention mainly uses dilute sugar liquid as a circulating heat exchange material to exchange heat with liquefied liquid, and does not adopt a flash evaporation process. The liquefied liquid at 108°C is directly cooled to the temperature required by the laminar liquefaction process through heat exchange with dilute sugar, thereby recovering heat energy, eliminating flash steam emissions, and reducing air pollution.

[0025] 2. The existing starch sugar production process usually requires multiple flash evaporation equipment, and the flash evaporation equipment needs to be connected to a steam recovery device or a condensed water recovery device. However, the present invention does not adopt a flash evaporation structure, and directly heats and cools each material through a heat exchanger, thereby reducing the equipment investment cost caused by the need to purchase flash evaporation equipment and recovery equipment.

[0026] 3. The system of the present invention can greatly save energy input and significantly improve the economic benefits of the enterprise.

[0027] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0029] Figure 1It is a structural schematic diagram of the starch saccharification system of the present invention.

[0030] Figure 2 It is a simplified process flow diagram of the operation of the starch saccharification system of the present invention.

[0031] Figure 3 It is a control logic schematic diagram of the temperature control system of the starch saccharification system of the present invention.

[0032] Notes:

[0033] 1 first heat exchanger; 2 first steam jet heater; 3 second heat exchanger; 4 laminar flow hydrolysis tank; 5 third heat exchanger; 6 saccharification tank; 7 evaporation concentration unit; 8 first steam drum; 9 second pump; 10 first pump; 11 pulp mixing tank; 101 first cold fluid feed port; 102 first cold fluid outlet; 103 first hot fluid feed port; 104 first hot fluid outlet; 301 second hot fluid feed port; 302 second cold fluid feed port; 303 second hot fluid outlet; 304 second cold fluid outlet; 501 third hot fluid feed port; 502 third cold fluid feed port; 503 third hot fluid outlet; 504 third cold fluid outlet; 601 first outlet; 602 first feed port; 603 second outlet; 12 second steam jet heater; 13 a second steam drum; 111 a discharge port of a slurry mixing tank; 112 a first temperature measuring device; 105 a second temperature measuring device; 106 a third temperature measuring device; 201 a fourth temperature measuring device; 305 a fifth temperature measuring device; 306 a sixth temperature measuring device; 505 a seventh temperature measuring device, 506 an eighth temperature measuring device; 604 a ninth temperature measuring device; 605 a tenth temperature measuring device; 121 an eleventh temperature measuring device; 113 a first solenoid valve; 107 a second solenoid valve; 108 a third solenoid valve; 202 a fourth solenoid valve; 307 a fifth solenoid valve; 308 a sixth solenoid valve; 507 a seventh solenoid valve; 508 an eighth solenoid valve; 606 a ninth solenoid valve; 607 a tenth solenoid valve; 122 an eleventh solenoid valve; 14 a control unit. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In the embodiment, the ports for inlet and outlet of the heat exchanger are named according to the following rules:

[0036] For the same heat exchanger, the port with a higher discharge temperature than the raw material is the hot fluid discharge port, and the port with a relatively lower temperature is the cold fluid discharge port. The port with a relatively higher feed temperature is the hot fluid feed port, and the port with a relatively lower feed temperature is the cold fluid feed port.

[0037] As an option, the heat exchanger may specifically use a honeycomb spiral plate heat exchanger. Example

[0038] An environmentally friendly starch saccharification system, see Figure 1 , 3 , including a slurry mixing tank 11, a three-stage heat exchanger (a first heat exchanger 1, a second heat exchanger 3 and a third heat exchanger 5), a first steam injection heater 2 and a second steam injection heater 12, a laminar hydrolysis tank 4, a saccharification tank 6, an evaporation concentration unit 7, a steam drum and connecting pipelines, auxiliary components arranged on the pipelines, such as pumps, valves, etc.

[0039] A first pump 10 is installed at the discharge port 111 of the slurry mixing tank, a pipeline is connected between the first pump 10 and the slurry mixing tank 11, and the discharge port of the first pump 10 is connected to the first cold fluid feed port 101 of the first heat exchanger 1 through the pipeline.

[0040] A second pump 9 is installed at the first hot fluid discharge port 104 of the first heat exchanger 1. The second pump 9 is connected to the first heat exchanger 1 via a pipeline. The discharge port of the second pump 9 is connected to the feed port of the first steam injection heater 2 connected to the first steam drum 8. The discharge port of the first steam injection heater 2 is installed with a second heat exchanger 3.

[0041] The discharge port of the first steam jet heater 2 is connected to the second hot fluid feed port 301 of the second heat exchanger 3 via a pipeline, and the second cold fluid discharge port 304 of the second heat exchanger 3 is connected to the laminar hydrolysis tank 4 .

[0042] The discharge port of the laminar hydrolysis tank 4 is connected to the third hot fluid feed port 501 of the third heat exchanger 5 , and the third cold fluid discharge port 504 of the third heat exchanger 5 is connected to the first feed port 602 of the saccharification tank 6 .

[0043] The first discharge port 601 of the saccharification tank 6 is connected to the second cold fluid feed port 302 of the second heat exchanger 3, and the second hot fluid discharge port 303 of the second heat exchanger 3 is connected to the first hot fluid feed port 103 of the first heat exchanger 1; the second discharge port 603 of the saccharification tank 6 is connected to the second steam injection heater 12 through a pipeline, and the discharge port of the second steam injection heater 12 is connected to the evaporation concentration unit 7 through a pipeline.

[0044] Meanwhile, the first cold fluid outlet 102 of the first heat exchanger 1 is connected to the third cold fluid feed port 502 of the third heat exchanger 5 through a pipeline. The third hot fluid outlet 503 of the third heat exchanger 5 is connected to the feed port of the evaporation concentration unit 7 through a pipeline.

[0045] Auxiliary components such as valves, pumps, temperature measuring devices, etc. on the pipeline that are not specifically introduced in the embodiments of the present invention, as well as the control relationship between the control system and each device can be set or executed by referring to conventional means, which does not affect the implementation of the innovative concept of this scheme and will not be described one by one.

[0046] As an example, in order to better realize the technical concept of the present invention and more accurately and flexibly control the temperature of the material or heat exchange medium, the following auxiliary element setting method is adopted.

[0047] See also Figure 3 , respectively, at the discharge port 111 of the slurry mixing tank, the first cold fluid discharge port 102 of the first heat exchanger 1, the first hot fluid discharge port 104, the discharge port of the first steam jet heater 2, the second hot fluid discharge port 303 and the second cold fluid discharge port 304 of the second heat exchanger 3, the third hot fluid discharge port 503 and the third cold fluid discharge port 504 of the third heat exchanger 5, the first feed port 602 and the second discharge port 603 of the saccharification tank 6, and the discharge port of the second steam jet heater 12, the first temperature measuring device 112, the second temperature measuring device 105, the third temperature measuring device 106, the fourth temperature measuring device 201, the fifth temperature measuring device 305, the sixth temperature measuring device 306, the seventh temperature measuring device 505, the eighth temperature measuring device 506, the ninth temperature measuring device 604, the tenth temperature measuring device 605, and the eleventh temperature measuring device 121 are installed to detect the temperature of each feed port and discharge port;

[0048] The first solenoid valve 113, the second solenoid valve 107, the third solenoid valve 108, the fourth solenoid valve 202, the fifth solenoid valve 307, the sixth solenoid valve 308, the seventh solenoid valve 507, the eighth solenoid valve 508, the ninth solenoid valve 606, the tenth solenoid valve 607 and the eleventh solenoid valve 122 are respectively installed at the above-mentioned inlet and outlet to control the transportation of materials at the corresponding inlet and outlet.

[0049] The above temperature measuring devices and solenoid valves are all regulated by the control unit 14 . Example

[0050] See also Figure 1-3 , a working method or process of the starch saccharification system described in the above-mentioned embodiment 1 is introduced below.

[0051] During the first operation, the first heat exchanger 1, the second heat exchanger 3, and the third heat exchanger 5 are not opened. After the starch is slurried in the slurry mixing tank 11, it is transported to the first steam jet heater 2 through a pipeline for heating, and then naturally cooled. When the fourth temperature measuring device 201 detects that the heated 108°C liquefied liquid is cooled to 98°C, it is fed back to the control unit 14 to open the fourth solenoid valve 202, and the liquefied liquid is transported to the laminar hydrolysis tank 4 for hydrolysis, and naturally cooled again. The eighth temperature measuring device 506 detects that the temperature has dropped to 60°C, and the control unit 14 controls the opening of the eighth solenoid valve 508, and the liquefied liquid enters the saccharification tank 6 for saccharification. When the temperature in the saccharification tank 6 drops to 65°C, a sufficient amount of dilute sugar liquid is collected for subsequent process flow.

[0052] After the first test run, the amount of dilute sugar required for one process flow is recorded, and a certain amount of 55° C. dilute sugar is pre-stored in the saccharification tank 6, and the amount of dilute sugar meets the amount required for one process flow.

[0053] The starch and the slurry water are stirred evenly in the slurry mixing tank 11. The starch emulsion that has completed the slurry mixing step enters the first heat exchanger 1 from the pipeline through the first cold fluid feed port 101. At the same time, the 65°C dilute sugar liquid enters the first heat exchanger 1 through the first hot fluid feed port 103. The 30°C starch emulsion and the 65°C dilute sugar liquid are countercurrently exchanged through the first heat exchanger 1. After the heat exchange, when the third temperature measuring device 106 detects that the temperature of the starch emulsion rises to 52°C, it is fed back to the control unit 14, and the third solenoid valve 108 is opened. The 52°C starch emulsion after heat exchange is transported to the first steam jet heater 2 through the first hot fluid discharge port 104 by the second pump 9. The first steam jet heater 2 The first steam drum 8 connected to provide steam is used to heat the starch emulsion through the first steam jet heater 2. When the fourth temperature measuring device 201 detects that the temperature of the liquefied liquid reaches 108°C, it is fed back to the control unit 14 to open the fourth solenoid valve 202. The liquefied liquid is transported from the discharge port of the first steam jet heater 2 to the second hot fluid feed port 301 through a pipeline and enters the second heat exchanger 3. At the same time, the 55°C dilute sugar liquid enters the second heat exchanger 3 through the second cold fluid feed port 302. In the second heat exchanger 3, the 108°C liquefied liquid exchanges heat with the 55°C dilute sugar. After the heat exchange, when the sixth temperature measuring device 306 detects that the temperature of the liquefied liquid drops to 98°C, it is fed back to The control unit 14 controls the opening of the sixth solenoid valve 308, and the 98°C liquefied liquid after heat exchange is transported to the laminar hydrolysis tank 4 through the second cold fluid outlet 304 through the pipeline. When the fifth temperature measuring device 305 detects that the temperature of the dilute sugar rises to 65°C, it feeds back to the control unit 14 to open the fifth solenoid valve, and the 65°C dilute sugar is transported from the second hot fluid outlet 303 to the first hot fluid feed port 103, and the 30°C starch emulsion is heated by heat exchange. The 98°C liquefied liquid after hydrolysis in the laminar hydrolysis tank 4 enters the third heat exchanger 5 through the third hot fluid feed port 501. At the same time, the 43°C dilute sugar transported from the first cold fluid outlet 102 is transported through the pipeline It is transported to the third cold fluid feed port 502 and enters the third heat exchanger 5. The liquefied liquid at 98°C and the diluted sugar at 43°C are subjected to countercurrent heat exchange. When the eighth temperature measuring device 506 detects that the liquefied liquid at 98°C is cooled to 60°C, it is fed back to the control unit 14 to control the opening of the eighth solenoid valve 508. The liquefied liquid at 60°C enters the saccharification tank 6 through the third cold fluid discharge port 504 through a pipeline for saccharification reaction. The diluted sugar liquid after heat exchange enters the evaporation and concentration unit 7 for evaporation and concentration. At the same time, the saccharified liquid in the saccharification tank 6 is heated by the second steam injection heater 12 and then transported from the discharge port of the second steam injection heater 12 through a pipeline to the evaporation and concentration unit 7 for evaporation and concentration.

[0054] Take 1000Kg (17Be, dry starch content 30%, i.e. 300Kg) starch milk as an example. Before heating by steam jet heater, the temperature of starch milk slurry is raised from 30℃ to 52℃, and the heat energy saved is: Q=CM△T=3.35KJ / Kg*1000Kg *22=73700KJ. At the same time, 0.5MPa saturated steam is converted into 108℃ hot water, which can release 2290KJ / Kg of heat. Every 1Kg of starch heated can save 0.1073Kg of 0.5MPa saturated steam. For a factory that consumes 200,000 tons of starch per year, this item alone can save 21,460T of steam, and can save about 3-4 million yuan per year.

[0055] The 98℃ liquefied liquid after laminar hydrolysis is used to heat the 43℃ dilute sugar. After the temperature of the liquefied liquid is reduced to 60℃, the acid is adjusted and the saccharifying enzyme is added to enter the saccharification process. After the dilute sugar liquid undergoes heat exchange, the temperature rises to 81℃ and enters the four-effect evaporator for evaporation and concentration. The heat absorbed by the dilute sugar from the liquefied liquid is: Q = CM△T = 3.35KJ / Kg*1000Kg *38=127300KJ. The temperature of 1000Kg of dilute sugar rises by 38℃, and the required heat energy is about 127300KJ, which is converted to 0.5MPa primary steam (0.5MPa steam becomes 90℃ condensed water to release heat energy 2375.82KJ / Kg) is 53.58Kg (converted to dry starch 0.2232Kg / kg dry starch). For a factory that consumes 200,000 tons of starch annually, this alone can save 44,640 tons of steam and 6-7 million yuan per year.

[0056] It can be seen that the starch saccharification system of the present invention can save energy consumption investment of nearly 10 million yuan, which can significantly improve the economic benefits of the enterprise.

[0057] Although the embodiments disclosed in the present invention are as above, the contents described are only embodiments adopted to facilitate understanding of the present invention and are not intended to limit the present invention. Any technician in the field to which the present invention belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. An environmentally friendly starch saccharification system, comprising a slurry mixing tank (11), a first heat exchanger (1), a second heat exchanger (3), a third heat exchanger (5), a first steam jet heater (2) and a second steam jet heater (12) provided with a steam drum, a laminar hydrolysis tank (4), a saccharification tank (6), an evaporation concentration unit (7) and a control unit (14); The discharge port (111) of the slurry mixing tank is connected to the first cold fluid feed port (101) of the first heat exchanger (1), the first hot fluid discharge port (104) of the first heat exchanger (1) is connected to the first steam jet heater (2), the discharge port of the first steam jet heater (2) is connected to the second hot fluid feed port (301) of the second heat exchanger (3), the second cold fluid discharge port (304) of the second heat exchanger (3) is connected to the laminar flow hydrolysis tank (4), the discharge port of the laminar flow hydrolysis tank (4) is connected to the third hot fluid feed port (501) of the third heat exchanger (5), and the third cold fluid discharge port (504) of the third heat exchanger (5) is connected to the first feed port (602) of the saccharification tank (6); The first discharge port (601) of the saccharification tank (6) is connected to the second cold fluid feed port (302) of the second heat exchanger (3), and the second hot fluid discharge port (303) of the second heat exchanger (3) is connected to the first hot fluid feed port (103) of the first heat exchanger (1); the first cold fluid discharge port (102) of the first heat exchanger (1) is connected to the third cold fluid feed port (502) of the third heat exchanger (5), and the third hot fluid discharge port (503) of the third heat exchanger (5) is connected to the feed port of the evaporation concentration unit (7); The second discharge port (603) of the saccharification tank (6) is connected to the second steam injection heater (12), and the discharge port of the second steam injection heater (12) is connected to the evaporation concentration unit (7); The control unit (14) controls the working states of the pulp mixing tank (11), the first heat exchanger (1), the second heat exchanger (3), the third heat exchanger (5), the first steam jet heater (2), the second steam jet heater (12), the laminar hydrolysis tank (4), the saccharification tank (6), the evaporation concentration unit (7), and auxiliary components arranged on the connecting pipelines therebetween.

2. The environmentally friendly starch saccharification system according to claim 1, characterized in that: The auxiliary components include a pump, a solenoid valve and a temperature measuring device.

3. The environmentally friendly starch saccharification system according to claim 2, characterized in that: A first pump (10) is provided at the discharge port (111) of the slurry mixing tank, and the discharge port of the first pump (10) is connected to the first cold fluid feed port (101) of the first heat exchanger (1).

4. The environmentally friendly starch saccharification system according to claim 2, characterized in that: The discharge port (111) of the slurry mixing tank, the first cold fluid discharge port (102) and the first hot fluid discharge port (104) of the first heat exchanger (1), the discharge port of the first steam jet heater (2), the second hot fluid discharge port (303) and the second cold fluid discharge port (304) of the second heat exchanger (3), the third hot fluid discharge port (503) and the third cold fluid discharge port (504) of the third heat exchanger (5), the first feed port (602) and the second discharge port (603) of the saccharification tank (6), and the discharge port of the second steam jet heater (12) are respectively provided with temperature measuring devices for detecting the temperature of each feed port and discharge port.

5. The environmentally friendly starch saccharification system according to claim 2, characterized in that: The discharge port (111) of the slurry mixing tank, the first cold fluid discharge port (102) and the first hot fluid discharge port (104) of the first heat exchanger (1), the discharge port of the first steam jet heater (2), the second hot fluid discharge port (303) and the second cold fluid discharge port (304) of the second heat exchanger (3), the third hot fluid discharge port (503) and the third cold fluid discharge port (504) of the third heat exchanger (5), the first feed port (602) and the second discharge port (603) of the saccharification tank (6), and the discharge port of the second steam jet heater (12) are respectively provided with electromagnetic valves that can be controlled to open and close to control the transportation of materials at the corresponding feed ports and discharge ports.

6. A starch saccharification method, characterized in that: The method is run in the environmentally friendly starch saccharification system described in any one of claims 1 to 5.

7. The starch saccharification method according to claim 6, characterized in that: When the environmentally friendly starch saccharification system is just started, the first heat exchanger (1), the second heat exchanger (3) and the third heat exchanger (5) are closed, and the starch is slurried in the slurry mixing tank (11) and then transported to the first steam jet heater (2) to be heated to 108°C, then naturally cooled to 98°C and transported to the laminar hydrolysis tank (4) for hydrolysis, and then naturally cooled to 60°C again and transported to the saccharification tank (6) for saccharification. When the temperature in the saccharification tank (6) drops to 65°C, a sufficient amount of dilute sugar liquid is collected and used as a heat exchange medium for subsequent processes.

8. The starch saccharification method according to claim 7, characterized in that: After there is dilute sugar liquid that can be used as a heat exchange medium in the starch saccharification system, the starch emulsion that has been slurried enters the first heat exchanger (1) through the first cold fluid feed port (101), and at the same time, the dilute sugar liquid at 65°C enters the first heat exchanger (1) through the first hot fluid feed port (103) to perform countercurrent heat exchange with the starch emulsion at 30°C; After heat exchange, the 52°C starch emulsion enters the first steam jet heater (2) through the first hot fluid outlet (104) and is heated to 108°C, and then enters the second heat exchanger (3) through the second hot fluid feed port (301). At the same time, the 55°C dilute sugar liquid enters the second heat exchanger (3) through the second cold fluid feed port (302). The 108°C liquefied liquid exchanges heat with the 55°C dilute sugar and is cooled to 98°C, while the dilute sugar liquid is heated to 65°C. The 98°C liquefied liquid is transported to the laminar hydrolysis tank (4) through the second cold fluid outlet (304), and the 65°C dilute sugar liquid is transported to the first hot fluid feed port (103) from the second hot fluid outlet (303) to heat exchange and heat the 30°C starch emulsion. The 98°C liquefied liquid after hydrolysis in the laminar flow hydrolysis tank (4) enters the third heat exchanger (5) through the third hot fluid feed port (501), and at the same time, the 43°C dilute sugar liquid output through the first cold fluid discharge port (102) enters the third heat exchanger (5) through the third cold fluid feed port (502). The 98°C liquefied liquid and the 43°C dilute sugar liquid are subjected to countercurrent heat exchange to obtain a 60°C liquefied liquid. After the heat exchange, the dilute sugar liquid enters the evaporation concentration unit (7) for evaporation concentration.

Images