Pasteurization steam direct injection mixer

Abstract

The invention discloses a pasteurization steam direct injection mixer, which comprises a steam inlet module, a spray head main body module, a jet flow module and an outlet module, and is characterized in that the steam inlet module and the outlet module are respectively connected with the spray head main body module; and the jet flow module is clamped and fixed with the spray head main body module through the outlet module. Aiming at the temperature rise working condition of pasteurization, a better gas-liquid mixing effect can be achieved, meanwhile, the temperature of mixed materials can be more uniform, and a better sterilization effect can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of food sterilization equipment, and in particular to a pasteurization steam direct injection mixer. Background Art

[0002] The main purpose of heat treatment of milk is to kill microorganisms and inactivate enzymes. The effectiveness of heat treatment and its impact on product quality are mainly related to the temperature-time combination, the heating method used and the pretreatment conditions of milk. At present, there are four main types of heat sterilization: preheating sterilization, pasteurization, ultra-high temperature instantaneous sterilization and maintenance sterilization. After a long period of scientific experiments and practical exploration, countries around the world have now formed a relatively unified production model, mainly pasteurization and ultra-high temperature instantaneous sterilization (UHT) sterilization. Two forms of heat processing.

[0003] In addition, an advanced sterilization method has emerged: direct steam injection sterilization. This technology is to inject steam directly into the milk to increase the temperature, and then pass it through the sterilization temperature pipe at high pressure to achieve instant sterilization. The core breakthrough of this technology is to retain the natural nutritional active protein in milk to the maximum extent. The direct steam injection sterilization process (infection, referred to as INF) has high heat transfer efficiency because of direct contact with the heating medium (steam) and then immediate cooling through vacuum, thereby limiting the product quality loss caused by excessive heat exposure. The main principle of direct steam injection sterilization is to fully mix the liquid phase fluid to be sterilized with the steam phase fluid, and use the high temperature of steam to sterilize the liquid phase fluid. It mainly includes two categories: (1) steam immersion sterilization (steam infusion): spraying the liquid phase fluid into a steam bath for sterilization; (2) steam injection sterilization (steam injection): the liquid phase is first formed into a ring jet, and then mixed with the injected steam for sterilization. Steam direct injection (INF) sterilizes directly. Due to the direct contact between the material and the heating medium (steam), the heat transfer efficiency is high, which greatly reduces the product quality loss caused by excessive heat exposure and can greatly improve the active nutrition of the product. At the same time, the direct heat transfer of steam also greatly reduces thermal damage and slagging due to the absence of heat transfer surface, avoiding the occurrence of pipe sticking.

[0004] At present, the direct steam injection sterilization technology mainly adopts a mixer structure such as that in CN101969782B to achieve the mixing and heat transfer of steam and materials. However, the mixing of steam and materials in this structure is only for a very short time through the annular slit. After the steam enters the material, it will form bubbles of larger size, which greatly reduces the speed of phase change heat transfer and cannot achieve full and complete mixing and heat transfer, resulting in uneven heating of the material and the local material temperature is lower than the sterilization temperature, affecting the sterilization effect. Therefore, when using the direct steam injection sterilization process, the sterilization temperature is usually 3-5°C higher than the traditional indirect sterilization temperature to ensure the sterilization effect. However, a higher sterilization temperature will also cause additional heating of the material, resulting in the loss of active business and sensory flavor. This is also one of the reasons why the application of direct steam injection sterilization technology is currently limited. Summary of the invention

[0005] Aiming at the problem of uneven gas-liquid mixing in existing steam direct injection mixers, the present invention proposes a pasteurization steam direct injection mixer, comprising a steam inlet module, a nozzle main body module, a jet module, and an outlet module, wherein the steam inlet module and the outlet module are respectively connected to the nozzle main body module; the jet module is clamped and fixed to the nozzle main body module through the outlet module.

[0006] Furthermore, the steam inlet module and the outlet module are respectively fastened to the nozzle main body module through threads, and the jet module is clamped and fixed when the outlet module and the nozzle main body module are fastened through threads.

[0007] Furthermore, the space between the steam inlet module and the jet module forms a vortex mixing chamber, and the liquid material inlet is connected to the vortex mixing chamber.

[0008] Furthermore, the steam inlet module includes a steam inlet, a compression section, a contraction accelerator, and a steam jet nozzle, and the diameter of the compression section is smaller than that of the steam inlet; the contraction accelerator is a conical structure, which is used to accelerate the steam after entering; the steam is ejected through the steam jet nozzle in the form of a supersonic jet and passes through the vortex mixing chamber.

[0009] Furthermore, a liquid material inlet is provided above the vortex mixing chamber, for liquid material to enter the vortex mixing chamber from the liquid material inlet.

[0010] Furthermore, the liquid material forms a high Reynolds number vortex in the vortex mixing chamber and is fully mixed with the supersonic steam, and the supersonic steam jet entrains the liquid material to form a gas-liquid mixture.

[0011] Furthermore, the gas-liquid mixture enters the collimated jet section of the jet module and continues to enter the shock wave expansion section; the gas-liquid mixture forms a shock wave in the shock wave expansion section, further promoting mixing, heat transfer and phase change processes.

[0012] Furthermore, the gas-liquid mixture fully transfers heat and changes phase in the relative mixing zone, gradually transforming into a liquid phase while slowing down; the relative mixing zone is connected to the material outlet.

[0013] Furthermore, the diameter of the compression section is 50%-70% of the diameter of the steam inlet; the diameter of the steam jet nozzle is 30%-50% of the diameter of the compression section; the cone angle of the compression section is 35°-45°; the distance between the steam jet nozzle and the collimated jet section is 35%-50% larger than the diameter of the steam jet nozzle; the diameter of the collimated jet section is 5%-8% larger than the diameter of the steam jet nozzle; the length of the collimated jet section is 10%-20% larger than the diameter of the steam jet nozzle; the length of the shock wave expansion section is 10%-15% larger than the length of the collimated jet section; and the diameter of the phase change mixing zone is the same as the length of the collimated jet section.

[0014] Furthermore, the diameter of the compression section is 60% of the diameter of the steam inlet; the diameter of the steam jet nozzle is 40% of the diameter of the compression section; the cone angle of the compression section is 30°; the distance between the steam jet nozzle and the collimated jet section is 42% larger than the diameter of the steam jet nozzle; the diameter of the collimated jet section is 6% larger than the diameter of the steam jet nozzle; the length of the collimated jet section is 15% larger than the diameter of the steam jet nozzle; the length of the shock wave expansion section is 13% larger than the length of the collimated jet section.

[0015] Beneficial effects of the present invention: 1. The present invention aims at the temperature rising condition of pasteurization and achieves better gas-liquid mixing effect; 2. The present invention can make the temperature of the mixed materials more uniform and achieve better sterilization effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention has the following accompanying drawings: Figure 1 is a schematic diagram of a pasteurization steam direct injection mixer of the present invention; Figure 2 Schematic diagram comparing the mixer of the present invention and the traditional mixer; Among them, 1. Steam inlet module; 2. Nozzle main body module; 3. Jet module; 4. Outlet module; 5. Steam inlet; 6. Compression section; 7. Contraction acceleration section; 8. Steam jet nozzle; 9. Liquid material inlet; 10. Vortex mixing chamber; 11. Collimated jet section; 12. Shock wave expansion section; 13. Phase change mixing zone; 14. Material outlet. DETAILED DESCRIPTION

[0017] In order to make the objects, advantages and features of the present invention more obvious, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] like Figure 1 As shown, a steam direct injection mixer comprises: 1. a steam inlet module; 2. a nozzle main body module; 3. a jet module; 4. an outlet module; 5. a steam inlet; 6. a compression section; 7. a contraction acceleration section; 8. a steam jet nozzle; 9. a liquid material inlet; 10. a vortex mixing chamber; 11. a collimated jet section; 12. a shock wave expansion section; 13. a phase change mixing zone; 14. a material outlet; wherein the steam inlet module 1 and the outlet module 4 are respectively fastened to the nozzle main body module 2 by threads, and the jet module 3 is clamped and fixed when the outlet module 4 is fastened to the nozzle main body module 2 by threads. The space between the inlet module 1 and the jet module 3 forms a vortex mixing chamber 10, and the liquid material inlet 9 is connected to the vortex mixing chamber 10.

[0019] Steam enters the steam inlet module 1 from the steam inlet 5 and enters the compression section 6. Since the diameter of the compression section 6 is smaller than the steam inlet 5, the steam is compressed and accelerated in the compression section 6. Subsequently, the steam enters the contraction acceleration section 7 with a conical structure for acceleration, and is ejected through the steam jet nozzle 8 as a supersonic jet, and passes through the vortex mixing chamber 10. The liquid material enters the vortex mixing chamber 10 from the liquid material 9. Since there is a supersonic steam jet at the center of the vortex mixing chamber 10, the liquid material is driven to form a high Reynolds number vortex in the vortex mixing chamber 10 and is fully mixed with the supersonic steam. Subsequently, the supersonic steam jet entrains the liquid material to form a gas-liquid mixture and enters the collimated jet section 11 of the jet module 3, and continues to maintain a high-speed state, and enters the shock wave expansion section 12. The gas-liquid mixture forms a shock wave in the shock wave expansion section 12, which further promotes the mixing, heat transfer and phase change processes. Next, the gas-liquid mixture achieves sufficient heat transfer and phase change in the phase mixing zone 13, and gradually changes to be mainly liquid phase, while achieving deceleration.

[0020] Relative size: 1) The diameter of the compression section 6 is 50%-70% of the diameter of the steam inlet 5, preferably about 60%; 2) The diameter of the steam jet nozzle 8 is 30%-50% of the diameter of the compression section 6, preferably about 40%; the cone angle of the compression section 6 is 35°-45°, preferably 30°; 3) The distance between the steam jet nozzle 8 and the collimated jet section 11 is 35%-50% larger than the diameter of the steam jet nozzle 8, preferably about 42%; 4) The diameter of the collimated jet section 11 is 5%-8% larger than the diameter of the steam jet nozzle 8; preferably about 6%; 5) The length of the collimated jet section 11 is 10%-20% greater than the diameter of the steam jet nozzle 8; preferably about 15%; 6) The length of the shock wave expansion section 12 is 10%-15% greater than the length of the collimated jet section 11; preferably about 13%; 7) The diameter of the phase change mixing zone 13 is the same as the length of the collimated jet section 11.

[0021] In order to better demonstrate the technical effect of the present invention, a specific embodiment is made and a comparative analysis is made with the traditional mixer, as follows: 1) The diameter of the steam inlet 5 is 30 mm; the diameter of the compression section 6 is 17 mm 2) The diameter of the steam jet nozzle 8 is 7 mm; the cone angle of the compression section 6 is 30°; 3) The distance between the steam jet nozzle 8 and the collimated jet section 11 is 10 mm 4) The diameter of the collimated jet section 11 is 7.4 mm; 5) The length of the collimated jet section 11 is 8 mm; 6) The length of the shock wave expansion section 12 is 9 mm; 7) The diameter of the phase change mixing zone 13 is 8 mm.

[0022] like Figure 2 As shown, the temperature fluctuation of the material within 1 hour after mixing and heating is compared between the mixer of the present invention and the conventional mixer. The mixer adopts the size in the specific embodiment. The material is milk, and the sterilization temperature is set to 85°C. It can be seen that the temperature fluctuation of the mixer of the present invention is between 84.8-85.3°C, while the temperature fluctuation of the conventional mixer is between 84.8-85.6°C. Compared with the conventional steam mixer, the present invention can achieve a better steam and liquid mixing effect, the temperature of the mixed material is more uniform, and a better sterilization effect can be achieved.

[0023] The above embodiments describe the technical solutions of the present invention in detail. Obviously, the present invention is not limited to the described embodiments. Based on the embodiments of the present invention, people familiar with the technical field can also make various changes accordingly, but any changes that are equivalent or similar to the present invention belong to the scope of protection of the present invention.

[0024] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A pasteurization steam direct injection mixer, characterized in that: It comprises a steam inlet module, a nozzle main body module, a jet module and an outlet module. The steam inlet module and the outlet module are respectively connected to the nozzle main body module; the jet module is clamped and fixed to the nozzle main body module through the outlet module.

2. A pasteurization steam direct injection mixer as claimed in claim 1, characterized in that: The steam inlet module and the outlet module are respectively fastened to the nozzle main body module through threads, and the jet module is clamped and fixed when the outlet module and the nozzle main body module are fastened through threads.

3. A pasteurization steam direct injection mixer as claimed in claim 2, characterized in that: The space between the steam inlet module and the jet module forms a vortex mixing chamber, and the liquid material inlet is communicated with the vortex mixing chamber.

4. A pasteurization steam direct injection mixer as claimed in claim 3, characterized in that: The steam inlet module includes a steam inlet, a compression section, a contraction accelerator, and a steam jet nozzle. The diameter of the compression section is smaller than that of the steam inlet. The contraction accelerator is a conical structure for accelerating the steam after entering. Steam is ejected through the steam jet nozzle in the form of a supersonic jet and passes through the vortex mixing chamber.

5. A pasteurization steam direct injection mixer as claimed in claim 4, characterized in that: A liquid material inlet is provided above the vortex mixing chamber, and is used for liquid material to enter the vortex mixing chamber from the liquid material inlet.

6. A pasteurization steam direct injection mixer as claimed in claim 5, characterized in that: The liquid material forms a high Reynolds number vortex in the vortex mixing chamber and is fully mixed with the supersonic steam. The supersonic steam jet entrains the liquid material to form a gas-liquid mixture.

7. A pasteurization steam direct injection mixer as claimed in claim 6, characterized in that: The gas-liquid mixture enters the collimated jet section of the jet module and continues to enter the shock wave expansion section; the gas-liquid mixture forms a shock wave in the shock wave expansion section, further promoting mixing, heat transfer and phase change processes.

8. A pasteurization steam direct injection mixer as claimed in claim 7, characterized in that: The gas-liquid mixture fully transfers heat and changes phase in the relative mixing zone, gradually transforming into a liquid phase while slowing down; the relative mixing zone is connected to the material outlet.

9. A pasteurization steam direct injection mixer as claimed in claim 8, characterized in that: The diameter of the compression section is 50%-70% of the diameter of the steam inlet; the diameter of the steam jet nozzle is 30%-50% of the diameter of the compression section; the cone angle of the compression section is 35°-45°; the distance between the steam jet nozzle and the collimated jet section is 35%-50% larger than the diameter of the steam jet nozzle; the diameter of the collimated jet section is 5%-8% larger than the diameter of the steam jet nozzle; the length of the collimated jet section is 10%-20% larger than the diameter of the steam jet nozzle; the length of the shock wave expansion section is 10%-15% larger than the length of the collimated jet section; the diameter of the phase change mixing zone is the same as the length of the collimated jet section.

10. A pasteurization steam direct injection mixer as claimed in claim 9, characterized in that: The diameter of the compression section is 60% of the diameter of the steam inlet; the diameter of the steam jet nozzle is 40% of the diameter of the compression section; the cone angle of the compression section is 30°; the distance between the steam jet nozzle and the collimated jet section is 42% larger than the diameter of the steam jet nozzle; the diameter of the collimated jet section is 6% larger than the diameter of the steam jet nozzle; the length of the collimated jet section is 15% larger than the diameter of the steam jet nozzle; the length of the shock wave expansion section is 13% larger than the length of the collimated jet section.

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