Starch raw material liquefaction waste heat recovery system

Abstract

The invention relates to a starchy raw material liquefaction waste heat recovery system, which belongs to the technical field of starch processing, and comprises a size mixing tank, a liquefier, a liquefaction maintaining tank, a flash separator, a laminar flow tank group and a saccharification removing tank which are sequentially communicated through pipelines, the waste heat recovery system further comprises a preheating recovery unit, the material output end of the size mixing tank is further communicated with the material input portion of the preheating recovery unit, the material input end of the flash separator is further communicated with the material output end of the preheating recovery unit, and the tail gas exhaust end of the flash separator is communicated with the heat exchange input end of the waste heat recovery unit. According to the invention, heat in starch liquefaction can be fully recovered, and the heat is applied to the starch liquefaction process, so that the purposes of energy conservation and emission reduction are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of cleaning, and in particular to a starchy raw material liquefaction waste heat recovery system. Background Art

[0002] Starch liquefaction is an important step in the production of starch sugar products. Starch liquefaction is the process in which starch macromolecules are decomposed into small molecular dextrins under the catalysis of amylase. Its purpose is to increase the solubility of starch so that the subsequent saccharification process can be carried out more effectively.

[0003] The existing starch liquefaction process includes: adding amylase to starch milk, adjusting the pH to 5.5-6.5, heating the slurry to perform a liquefaction reaction, and then flashing the slurry, cooling it after the flashing, and transporting it to the saccharification section. With respect to the above-mentioned technology, the inventor believes that in the starch liquefaction process, since circulating water is usually used to cool the slurry, the process consumes a large amount of circulating water to eliminate the heat of the slurry after flashing, thereby causing a waste of heat and circulating water, and there is also a phenomenon of heat loss in the process of exhaust gas discharge during the flashing process. Summary of the invention

[0004] The purpose of the present invention is to provide a starch raw material liquefaction waste heat recovery system to fully recover the heat in starch liquefaction and apply the heat to the starch liquefaction process to achieve energy saving and emission reduction effects.

[0005] The present invention provides a starchy raw material liquefaction waste heat recovery system, which adopts the following technical scheme:

[0006] A starch raw material liquefaction waste heat recovery system, comprising a slurry mixing tank, a liquefier, a liquefaction maintenance tank, a flash separator, a laminar flow tank group and a desaccharification tank which are sequentially connected through pipelines;

[0007] It also includes a preheating recovery unit, the material output end of the slurry mixing tank is also connected to the material input part of the preheating recovery unit, the material input end of the flash separator is also connected to the material output end of the preheating recovery unit, and the tail gas discharge end of the flash separator is connected to the heat exchange input end of the waste heat recovery unit.

[0008] Preferably, a liquefied liquid buffer tank is further provided between the laminar flow tank group and the desaccharification tank, the material output end of the liquefied liquid buffer tank is connected to the material input end of the preheating recovery unit, and the material output end of the preheating recovery unit is connected to the material input end of the desaccharification tank.

[0009] Preferably, a liquefied liquid outlet pump is provided between the material output end of the liquefied liquid buffer tank and the preheating recovery unit.

[0010] Preferably, the material output end of the liquefied liquid pump is also connected to the material input end of the desaccharification tank.

[0011] Preferably, a starch emulsion pump is provided at the material output end of the slurry mixing tank.

[0012] Preferably, a starch milk ejector is provided at the output end of the starch milk pump.

[0013] Preferably, the preheat recovery unit is also connected to a steam recovery unit.

[0014] Preferably, the laminar flow tank group includes a plurality of groups of unit laminar flow tanks connected in sequence, and each group of the unit laminar flow tanks is connected to the flash separator.

[0015] In summary, the present invention includes the following beneficial technical effects:

[0016] 1. During the starch liquefaction process, the temperature of the material output from the slurry mixing tank is generally 35-45°C. The liquefier needs to heat the material from the slurry mixing tank to 110-112°C and transport it to the liquefaction maintenance tank. The flash separator flashes the material from the liquefaction maintenance tank at 100-102°C. The material treated by the flash separator enters the laminar flow tank group and the desaccharification tank in turn. The tail gas discharge end of the flash separator is connected to the heat exchange input part of the preheat recovery unit, so that the preheat recovery unit recovers the waste heat in the tail gas of the flash separator, and the material output end of the slurry mixing tank is also connected to the material input part of the preheat recovery unit, and the material input end of the flash separator is also connected to the material output end of the preheat recovery unit, so that the waste heat in the tail gas of the flash separator collected by the waste heat recovery machine is used to heat the material, thereby reducing the amount of steam used by the flash separator and fully recovering the waste heat.

[0017] 2. A liquefied liquid buffer tank is also arranged between the laminar flow tank group and the desaccharification tank. The temperature of the material in the laminar flow tank group is generally 98-100°C. The material output end of the liquefied liquid buffer tank is connected with the material input end of the preheating recovery unit, so that the heat exchanger in the preheating recovery unit absorbs the heat of the material. The material output end of the preheating recovery unit is connected with the material input end of the desaccharification tank, so that the temperature of the material entering the desaccharification tank is reduced to 60-65°C, and then circulating water is used to reduce the temperature of the material in the desaccharification tank to 58-62°C. This process reduces the use of circulating water, and also uses the temperature of the material in the liquefied liquid buffer tank to heat the material transported to the liquefied liquid in the preheating recovery unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of a starchy raw material liquefaction waste heat recovery system provided in an embodiment of the present invention.

[0019] Explanation of the reference numerals: 1. slurry mixing tank; 11. starch emulsion pump; 2. liquefier; 3. liquefaction maintenance tank; 4. flash separator; 5. laminar flow tank group; 6. desaccharification tank; 7. preheating recovery unit; 71. steam recovery unit; 8. starch emulsion ejector; 9. liquefied liquid buffer tank; 91. liquefied liquid outlet pump. DETAILED DESCRIPTION

[0020] The following is combined with Figure 1 The present invention is described in further detail.

[0021] The present invention provides a system for recovering waste heat from liquefaction of starchy raw materials. Figure 1 , including a slurry mixing tank 1, a liquefier 2, a liquefaction maintenance tank 3, a flash separator 4, a laminar flow tank group 5 and a desaccharification tank 6 connected end to end by a pipeline; the system also includes a preheating recovery unit 7. The preheating recovery unit 7 in this embodiment is a prior art, which mainly includes a steam regenerator and a heat exchanger, and is mainly used to recover the heat lost in the starch liquefaction process, and is used in the heating and steam regeneration process of the starch milk material to achieve the purpose of recycling heat.

[0022] Reference Figure 1 In this embodiment, the temperature of the starch milk material output from the slurry mixing tank 1 is generally 35-45°C. The liquefier 2 needs to heat the material from the slurry mixing tank 1 to 110-112°C and transport it to the liquefaction maintenance tank 3 for maintenance. The flash separator 4 performs a flash treatment at 100-102°C on the material from the liquefaction maintenance tank 3, wherein the temperature difference between the starch milk material in the flash separator 4 and the liquefier 2 is 8-12°C. The tail gas discharge end of the flash separator 4 is connected to the heat exchange input end of the preheat recovery unit 7, and the preheat recovery unit 7 is used to recover the heat of the liquefied flash gas discharged from the flash separator 4; the material output end of the slurry mixing tank 1 is also connected to the material input part of the preheat recovery unit 7 through a pipeline, that is, a part of the starch milk material output by the slurry mixing tank 1 enters the material input end of the preheat recovery unit 7, and a part enters the material input end of the flash separator 4, and the starch milk material entering the preheat recovery unit 7 is heated by the recovered liquefied flash gas; the material input end of the flash separator 4 is also connected to the material output end of the preheat recovery unit 7 through a pipeline, that is, the material input end of the flash separator 4 receives the starch milk material transported by the slurry mixing tank 1, and the material input end of the flash separator 4 also receives the starch milk material heated by the waste heat of the liquefied flash gas recovered to the preheat recovery unit 7.

[0023] Reference Figure 1The material output end of the slurry mixing tank 1 is connected to a starch emulsion pump 11, and the output end of the starch emulsion pump 11 is connected to a starch emulsion ejector 8, that is, the starch emulsion material output from the slurry mixing tank 1 is transported under the action of the starch emulsion pump 11, and the starch emulsion ejector 8 atomizes the starch emulsion to facilitate subsequent production work. A part of the starch emulsion material treated by the starch emulsion ejector 8 enters the material input end of the liquefied gas, and the other part enters the material input end of the preheating recovery unit 7.

[0024] Reference Figure 1 In this embodiment, the material treated by the flash separator 4 is transported to the laminar flow tank group 5, which includes a plurality of unit laminar flow tanks connected end to end, and each unit laminar flow tank is connected to the flash separator 4; the temperature of the starch milk material in the laminar flow tank group 5 is 100°C. A liquefied liquid buffer tank 9 is also connected between the laminar flow tank group 5 and the desaccharification tank 6, and the liquefied liquid buffer tank 9 plays the role of high liquid level alarm shutdown. The material output end of the liquefied liquid buffer tank 9 is connected to the other material input end of the preheating recovery unit 7, and the other material output end of the preheating recovery unit 7 is connected to the material input end of the desaccharification tank 6.

[0025] Reference Figure 1 , a liquefied liquid pump 91 is connected between the material output end of the liquefied liquid buffer tank 9 and the preheating recovery unit 7, and the material output end of the liquefied liquid pump 91 is also connected to the material input end of the desaccharification tank 6. That is, the starch milk material output from the liquefied liquid buffer tank 9 is transported under the action of the liquefied liquid pump 91, and the temperature of the starch milk material output from the liquefied liquid buffer tank 9 is 95-98°C. Under the action of the liquefied liquid pump 91, a part of the starch milk material flows to the desaccharification tank 6, and the other part of the starch milk material flows to the other material input end of the preheating recovery unit 7. The preheating recovery unit 7 absorbs the heat of the starch milk material transported from the liquefied liquid buffer tank 9, so that the temperature of the starch milk material output from the other material output end of the preheating recovery unit 7 to the desaccharification tank 6 is 60-65°C, thereby reducing the temperature of the starch milk material flowing to the desaccharification tank 6. The desaccharification tank 6 needs to reduce the internal starch milk temperature to 58-62°C, thereby reducing the use of circulating water.

[0026] Reference Figure 1 The preheating recovery unit 7 in this embodiment is also connected to a steam recovery unit 71 to transport the steam with heat to external equipment to reduce the heat in the preheating recovery unit 7 and avoid overheating the starch milk material from the slurry mixing tank 1, thereby affecting the product quality. Therefore, the temperature of the material flowing from the material output end of the preheating recovery unit 7 to the liquefier 2 is controlled below 60°C.

[0027] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A starchy raw material liquefaction waste heat recovery system, characterized in that: It comprises a pulping tank (1), a liquefier (2), a liquefaction maintenance tank (3), a flash separator (4), a laminar flow tank group (5) and a desaccharification tank (6) which are sequentially connected through pipelines; It also includes a preheating recovery unit (7), the material output end of the slurry mixing tank (1) is also connected to the material input part of the preheating recovery unit (7), the material input end of the flash separator (4) is also connected to the material output end of the preheating recovery unit (7), and the tail gas discharge end of the flash separator (4) is connected to the heat exchange input end of the waste heat recovery unit.

2. A starchy raw material liquefaction waste heat recovery system according to claim 1, characterized in that: A liquefied liquid buffer tank (9) is further provided between the laminar flow tank group (5) and the desaccharification tank (6); a material output end of the liquefied liquid buffer tank (9) is connected to a material input end of the preheating recovery unit (7); and a material output end of the preheating recovery unit (7) is connected to a material input end of the desaccharification tank (6).

3. A starchy raw material liquefaction waste heat recovery system according to claim 2, characterized in that: A liquefied liquid outlet pump (91) is provided between the material output end of the liquefied liquid buffer tank (9) and the preheating recovery unit (7).

4. A starchy raw material liquefaction waste heat recovery system according to claim 3, characterized in that: The material output end of the liquefied liquid pump (91) is also connected to the material input end of the desaccharification tank (6).

5. The starch material liquefaction waste heat recovery system according to claim 1, characterized in that: A starch emulsion pump (11) is provided at the material output end of the slurry mixing tank (1).

6. A starchy material liquefaction waste heat recovery system according to claim 5, characterized in that: The output end of the starch milk pump (11) is provided with a starch milk ejector (8).

7. The starch material liquefaction waste heat recovery system according to claim 1, characterized in that: The preheat recovery unit (7) is also connected to a steam recovery unit (71).

8. The starch material liquefaction waste heat recovery system according to claim 1, characterized in that: The laminar flow tank group (5) comprises a plurality of groups of sequentially connected unit laminar flow tanks, and each group of the unit laminar flow tanks is in a state of being connected to the flash separator (4).

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