A spray drying apparatus for the dehydration of yeast using water vapour as the medium

Abstract

The utility model relates to a kind of spray drying device for yeast dehydration with water vapor as medium, comprising: steam generator, with the steam output port of output steam;Spray dryer has opposite material inlet, material drying outlet, hot air inlet and hot air outlet, hot air inlet is communicated steam output port, material drying outlet is equipped with the first discharge valve for unloading drying material;Cyclone collector, cyclone collector is communicated hot air outlet;Heat pipe heat exchanger is installed between cyclone collector and hot air outlet, and the heat exchange medium pipeline of heat pipe heat exchanger is communicated the heating system of steam generator.Such, using water vapor instead of traditional air as drying medium, using the high specific heat capacity and latent heat characteristics of water vapor, improve drying efficiency and thermal efficiency, relatively lower energy consumption.Moreover, the present application can recycle the heat in the tail gas of spray dryer by setting heat pipe heat exchanger, which can further reduce energy consumption.

Description

Technical Field

[0001] This utility model relates to the field of spray drying technology, and in particular to a spray drying device for yeast dehydration using water vapor as a medium. Background Technology

[0002] In the process of producing single-cell protein (SCP) through microbial fermentation, drying is a crucial step. Its purpose is to effectively remove moisture from fermenting yeasts and other microorganisms to obtain a stable, storable product. Currently, commonly used industrial drying technologies include drum drying and spray drying. Among these, spray drying technology, due to its fast drying speed, high efficiency, and good product solubility and flowability, is particularly suitable for drying heat-sensitive microbial proteins, effectively preserving protein activity and nutrients, and has become one of the mainstream choices. In the entire process of spray drying technology, which uses air as the heat exchange medium, the spray drying system achieves efficient drying of microbial proteins through multiple stages, including air handling, material atomization, heat exchange drying, product collection, and exhaust gas treatment, ensuring product quality and the environmental friendliness of the production process.

[0003] However, existing spray drying technology using air as the heat exchange medium faces significant technical bottlenecks when applied to drying proteins from microorganisms such as yeast, and the following problems exist:

[0004] Significant heat loss: A large amount of heat is discharged with the exhaust gas, the system thermal efficiency is generally low (usually only 50%-60%), and energy waste is prominent.

[0005] Air has limited heat carrying capacity: air has a low specific heat capacity, and in order to meet the heat demand for rapid evaporation of moisture, it must be heated to a high temperature and maintained at a large flow rate, resulting in huge heating energy consumption.

[0006] High power consumption: Handling large volumes of air requires high-power fans, significantly increasing power consumption. Especially when producing fine powder products, the entrainment loss of exhaust gas (approximately 20%) necessitates the use of efficient and expensive separation devices, further increasing system complexity and cost.

[0007] The drying time is relatively long: Compared with some new drying technologies, its drying cycle is longer, and continuous operation in large-scale production scenarios exacerbates the energy consumption problem.

[0008] Insufficient temperature control precision: Yeast is extremely sensitive to changes in drying temperature, and traditional air spray drying equipment has limitations in accurately maintaining a suitable and stable drying temperature, which directly affects drying efficiency and the survival rate / activity of the final product.

[0009] Therefore, although researchers have tried to alleviate the above problems by optimizing process parameters (such as inlet air temperature / pressure and feed rate), adding protective agents (such as lactose and trehalose), or using microencapsulation technology, the inherent high energy consumption and potential damage to microbial activity of air-based spray drying remain the core challenges restricting its more efficient and economical application in this field. Utility Model Content

[0010] Therefore, it is necessary to provide a spray drying device for yeast dehydration using water vapor as a medium, which has relatively low energy consumption, can improve drying efficiency and drying effect, and has relatively convenient process control.

[0011] This application provides a spray drying apparatus for yeast dehydration using water vapor as a medium, comprising:

[0012] A steam generator with a steam outlet for outputting steam;

[0013] A spray dryer has a material inlet, a material drying outlet, a hot air inlet, and a hot air outlet. The hot air inlet is connected to the steam outlet, and the material drying outlet is equipped with a first discharge valve for unloading the dried material.

[0014] A cyclone collector, wherein the cyclone collector is connected to the hot air outlet;

[0015] A heat pipe heat exchanger is installed between the cyclone collector and the hot air outlet, and the heat exchange medium pipeline of the heat pipe heat exchanger is connected to the heating system of the steam generator.

[0016] In one embodiment, the spray drying apparatus further includes a material tank and a feed pump, the material tank being connected to the material inlet via the feed pump.

[0017] In one embodiment, a filter is also installed between the steam outlet of the steam generator and the hot air inlet of the spray dryer.

[0018] In one embodiment, the cyclone collector has a gas outlet, a main ash discharge outlet and an auxiliary ash discharge port. The gas outlet is equipped with a tail gas condenser and a tail gas filter. The main ash discharge outlet is equipped with a second discharge valve. The auxiliary ash discharge port is equipped with an airlock discharge valve.

[0019] In one embodiment, the drying tower of the spray dryer has multiple atomization layers.

[0020] In one embodiment, the drying tower of the spray dryer has 2-4 atomizing layers.

[0021] In one embodiment, the drying tower of the spray dryer is made of stainless steel.

[0022] In one embodiment, a preheating water tank is added before the water inlet of the steam generator. A heat pipe condensing section coil is installed in the preheating water tank, and the heat pipe condensing section coil is connected to the heat exchange medium pipeline of the heat pipe heat exchanger.

[0023] In one embodiment, the steam generator has a water preheating chamber, in which a heat pipe condenser coil is arranged, and the heat pipe condenser coil is connected to the heat exchange medium pipeline of the heat pipe heat exchanger.

[0024] In one embodiment, the steam generator is equipped with a pressure regulating valve and a pressure sensor.

[0025] The aforementioned spray drying device for yeast dehydration using water vapor as a medium incorporates a steam generator. The steam generated by the steam generator is connected to the hot air inlet of the spray dryer. By using water vapor instead of traditional air as the drying medium, and leveraging the high specific heat capacity and latent heat of water vapor, drying efficiency and thermal efficiency are improved, resulting in relatively low energy consumption. Furthermore, by using water vapor as the medium, the temperature of the water vapor can be directly controlled by adjusting the pressure. In this case, the control system mainly consists of a steam generator, a pressure regulating valve, and a pressure sensor. The steam generator produces water vapor, and the pressure regulating valve precisely controls the water vapor pressure by changing its opening, thereby controlling the temperature. The pressure sensor monitors the pressure in real time and feeds it back to the control system to ensure the stability of the water vapor pressure and temperature. Since the pressure and temperature of saturated water vapor correspond one-to-one, this control method is simple and effective. In contrast, the temperature control system of a conventional air-medium spray dryer requires multiple devices to work together, while the water vapor system can control the temperature simply by adjusting the pressure, reducing equipment requirements and simplifying control. Moreover, by incorporating a heat pipe heat exchanger, the heat in the exhaust gas of the spray dryer can be recovered and reused, further reducing energy consumption. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a spray drying apparatus according to an embodiment of the present invention. Detailed Implementation

[0027] To facilitate understanding of this utility model and to make the aforementioned objects, features, and advantages of this utility model more apparent, the specific embodiments of this utility model are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this utility model, and preferred embodiments are shown in the accompanying drawings. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this utility model. This utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model; therefore, this utility model is not limited to the specific embodiments disclosed below. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly and specifically defined. All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the utility model.

[0028] This application provides a spray drying apparatus for yeast dehydration using water vapor as a medium. Please refer to [link to relevant documentation]. Figure 1 The spray drying device includes a steam generator 100, a spray dryer 300, a heat pipe heat exchanger 700, and a cyclone collector 400 connected to each other. The steam generator 100 is used to provide steam as a heat medium to the spray dryer 300. The spray dryer is used to dehydrate yeast by spray drying. The heat pipe heat exchanger is used to recover the waste heat of the exhaust gas of the spray dryer and exchange it with the steam generator. The cyclone collector is used to collect the yeast material in the exhaust gas for a second time.

[0029] The steam generator 100 has a steam outlet for outputting steam; the steam generator 100 is used to heat water into steam, for example, to generate steam with a temperature range of 150℃-250℃, or to generate high-pressure steam with a temperature range of 150℃-250℃.

[0030] The spray dryer 300 has a material inlet 310, a material drying outlet 330, a hot air inlet 320, and a hot air outlet 340. The hot air inlet 320 is connected to the steam outlet, and the material drying outlet 330 is equipped with a first discharge valve 350 for unloading the dried material. In this application, the spray dryer is used to dry yeast liquid to be dried by spray drying. The material inlet is used to connect to the yeast liquid to be dried. It should be noted that the spray dryer typically includes an atomizer, which is installed in the drying tower. The pressurized yeast liquid enters the atomizer at the top of the drying tower and is dispersed into tiny droplets. These droplets have a large specific surface area, which is beneficial for rapid drying. Heated water vapor enters from the side or bottom of the drying tower and comes into full contact with the atomized droplets for heat exchange. The yeast droplets rapidly evaporate moisture during contact with the hot steam, forming a dried powdery or granular product. The dried product falls to the bottom of the drying tower.

[0031] The cyclone collector 400 is connected to the hot air outlet 340. In this application, the dried air containing product particles enters the cyclone separator, where centrifugal force separates larger particles from the airflow. The separated product is collected through a discharge valve. By setting up the cyclone collector 400, this application further collects the material in the exhaust gas flowing out of the hot air outlet 340, reducing material waste.

[0032] A heat pipe heat exchanger 700 is installed between the cyclone collector 400 and the hot air outlet 340, and the heat exchange medium pipeline of the heat pipe heat exchanger 700 is connected to the heating system of the steam generator. In this application, the heat of the exhaust gas from the hot air outlet 340 of the spray dryer 300 is further recovered through the heat pipe heat exchanger 700 and used as the heating system of the steam generator, thereby reducing heat energy waste.

[0033] The aforementioned spray drying device for yeast dehydration using water vapor as a medium, by incorporating a steam generator, connects the steam generated by the generator to the hot air inlet of the spray dryer. By using water vapor instead of traditional air as the drying medium, and leveraging the high specific heat capacity and latent heat of water vapor, drying efficiency and thermal efficiency are improved, resulting in relatively low energy consumption. Furthermore, by using water vapor as the medium, the temperature of the water vapor can be directly controlled by adjusting the pressure. In this case, the control system mainly consists of a steam generator, a pressure regulating valve, and a pressure sensor. The steam generator produces water vapor, and the pressure regulating valve precisely controls the pressure of the water vapor by changing its opening, thereby controlling the temperature. The pressure sensor monitors the pressure in real time and feeds it back to the control system to ensure the stability of the water vapor pressure and temperature. Since the pressure and temperature of saturated water vapor correspond one-to-one, this control method is simple and effective. In contrast, the temperature control system of a conventional spray dryer requires multiple devices to work together, while the water vapor medium system can control the temperature simply by adjusting the pressure, reducing equipment requirements and simplifying control. Moreover, by incorporating a heat pipe heat exchanger, the heat in the exhaust gas of the spray dryer can be recovered and utilized, further reducing energy consumption.

[0034] In one embodiment, please refer to Figure 1 The spray drying device also includes a material tank 500 and a feed pump 600. The material tank 500 stores yeast liquid to be dried. The material tank 500 is connected to the material inlet 310 through the feed pump 600. Thus, by setting the feed pump 600, it is convenient to pump the yeast liquid to be dried to the spray dryer for spray drying.

[0035] In one embodiment, please refer to Figure 1 A filter 200 is also installed between the steam outlet of the steam generator 100 and the hot air inlet 320 of the spray dryer 300. In this way, dust and other substances can be filtered out by setting up the filter.

[0036] In one embodiment, the cyclone collector 400 has a gas outlet 430, a main ash discharge outlet 410, and an auxiliary ash discharge outlet 420. The gas outlet 430 is equipped with a tail gas condenser 431 and a tail gas filter 432. The tail gas from the gas outlet 430 is discharged after being treated by the tail gas condenser 431 and the tail gas filter 432. The main ash discharge outlet 410 of the cyclone collector 400 is equipped with a second discharge valve 411, and the auxiliary ash discharge outlet 420 is equipped with an airlock discharge valve 421, both used to collect the dried yeast particles.

[0037] In one embodiment, the drying tower of the spray dryer has multiple atomization layers. For example, the drying tower of the spray dryer has 2-4 atomization layers. This results in better spray drying effect. For example, the tower body of the spray dryer is made of stainless steel, which provides high-temperature resistance and corrosion resistance. For example, the tower body material and pressure-resistant design: the tower body is made of high-temperature resistant, corrosion-resistant, and smooth stainless steel to ensure it can withstand the high-temperature and high-pressure environment of water vapor and prevent damage to the tower body. At the same time, the tower body design must fully consider the pressure of water vapor to ensure the strength and stability of the overall structure and prevent deformation or leakage under high temperature and high pressure. For example, multiple high-efficiency atomizing devices are installed inside the tower to ensure that the yeast protein liquid can be evenly dispersed into tiny droplets, increasing the contact area with water vapor and improving drying efficiency. Simultaneously, the layout of the baffles and guide plates inside the tower is rationally designed to ensure that water vapor and droplets are fully mixed and in contact, extending the drying time while preventing droplets from directly impacting the tower wall and reducing wall adhesion. For example, proper insulation of the drying tower can reduce heat loss to the outside, improve thermal efficiency, and reduce energy consumption.

[0038] For example, a heat pipe heat exchanger can be used as a heat recovery device, installed in the exhaust gas pipeline. The heat pipe heat exchanger utilizes the phase change of the working fluid inside the heat pipe during evaporation and condensation to transfer heat, featuring high efficiency, high reliability, and a compact structure. When high-temperature exhaust gas passes through the heat pipe heat exchanger, heat is transferred to the heat pipe, and the working fluid inside the heat pipe evaporates, transferring heat to the other side for preheating steam or other media requiring heating, thus achieving heat recovery and reuse. For instance, the heat pipe heat exchanger can be installed at the front end of an exhaust gas treatment system, ensuring that high-temperature exhaust gas first enters the heat exchanger for heat exchange. The cold side of the heat exchanger is connected to the preheating pipeline of the steam supply system, using the recovered heat to heat the steam entering the drying tower, reducing the energy consumption of the steam generator.

[0039] In one embodiment, a preheating water tank is added before the water inlet of the steam generator. A heat pipe condenser coil is installed inside the preheating water tank, and the heat pipe condenser coil is connected to the heat exchange medium pipeline of the heat pipe heat exchanger. For example, the steam generator has a water preheating chamber, in which a heat pipe condenser coil is installed, and the heat pipe condenser coil is connected to the heat exchange medium pipeline of the heat pipe heat exchanger. For example, the steam generator is equipped with a pressure regulating valve and a pressure sensor.

[0040] The aforementioned spray drying device for yeast dehydration using water vapor as a medium, by incorporating a steam generator, connects the steam generated by the generator to the hot air inlet of the spray dryer. By using water vapor instead of traditional air as the drying medium, and leveraging the high specific heat capacity and latent heat of water vapor, drying efficiency and thermal efficiency are improved, resulting in relatively low energy consumption. Furthermore, by using water vapor as the medium, the temperature of the water vapor can be directly controlled by adjusting the pressure. In this case, the control system mainly consists of a steam generator, a pressure regulating valve, and a pressure sensor. The steam generator produces water vapor, and the pressure regulating valve precisely controls the pressure of the water vapor by changing its opening, thereby controlling the temperature. The pressure sensor monitors the pressure in real time and feeds it back to the control system to ensure the stability of the water vapor pressure and temperature. Since the pressure and temperature of saturated water vapor correspond one-to-one, this control method is simple and effective. In contrast, the temperature control system of a conventional spray dryer requires multiple devices to work together, while the water vapor medium system can control the temperature simply by adjusting the pressure, reducing equipment requirements and simplifying control. Moreover, by incorporating a heat pipe heat exchanger, the heat in the exhaust gas of the spray dryer can be recovered and utilized, further reducing energy consumption.

[0041] This application incorporates a dedicated steam generator to produce high-pressure steam, such as steam with a temperature range of 150℃-250℃. A high-precision pressure control system ensures stable and controllable steam temperature throughout the drying process, meeting the needs of different yeast protein drying stages. This reduces the need for essential temperature control components found in traditional spray drying equipment, such as heaters, temperature sensors, blowers, and PID controllers.

[0042] In this application, an automatic control system can be equipped to monitor the exhaust gas temperature, pressure, and the operating status of the heat pipe heat exchanger in real time. The system can automatically adjust the heat exchanger's operating parameters according to actual conditions to ensure maximum heat recovery efficiency while guaranteeing the safe and stable operation of the system. For example, the spray drying device also includes a PLC controller, which is electrically connected to the steam generator, spray dryer, cyclone collector, and heat pipe heat exchanger. All components of the steam generator, spray dryer, cyclone collector, and heat pipe heat exchanger are controlled by the PLC controller.

[0043] The following section provides a comparative analysis of the throughput of spray drying equipment using air and water vapor as media.

[0044] Based on a common small centrifugal spray dryer, some of its parameters are as follows: moisture evaporation rate: 10 kg / h, air inlet temperature: 260℃, air volume of blower: 9.5 m3 / min, drying chamber diameter: 1200 mm, drying tower height: 1200 mm.

[0045] Calculation basis:

[0046] Specific heat capacity of air: 1.005 kJ / (kg·℃)

[0047] Air density (at 210℃): approximately 0.897 kg / m³

[0048] Specific heat capacity of water vapor (dry steam): 1.88 kJ / (kg·℃)

[0049] Water vapor density (210℃, saturated vapor): approximately 0.818 kg / m³

[0050] Calculation process:

[0051] Assume that during the drying process, the inlet temperature is 210℃, the outlet temperature is 180℃, and the drying time is 5 seconds.

[0052] Air medium:

[0053] Airflow: 9.5m 3 / min=0.158m 3 / s

[0054] Air mass flow rate: 0.158 m³ / h 3 / s×0.897kg / m 3 ≈0.142kg / s

[0055] Heat provided by the air: Qair = m˙air·cp, air·(Tin - Tout)

[0056] Qair=0.142kg / s×1.005kJ / (kg\cdotp℃)×(210-180)℃=4.28kJ / s=4.28kW

[0057] Water vapor medium:

[0058] Water vapor flow rate: Assuming the same volumetric flow rate as air, i.e., 9.5 m³ / h. 3 / min=0.158m 3 / s

[0059] Water vapor mass flow rate: 0.158 m³ 3 / s×0.818kg / m 3 ≈0.129kg / s

[0060] The heat provided by water vapor: Qsteam=m˙steam·cp,steam·(Tin-Tout)

[0061] Qsteam=0.129kg / s×1.88kJ / (kg\cdotp℃)×(210-180)℃=7.43kJ / s=7.43kW

[0062] Processing volume comparison

[0063] In spray drying, the mass of water evaporated per unit time is directly proportional to the heat provided. Based on the above calculations:

[0064] Qsteam / Qair=7.43kw / 4.28kw=1.74

[0065] As can be seen from the above, the spray drying equipment using water vapor as the medium in this application has significantly increased the throughput per unit volume by 74%.

[0066] Conclusion: Under the same volumetric flow rate, the water evaporation rate of spray drying equipment using water vapor as the medium is higher than that of equipment using air as the medium. This is mainly because water vapor has a higher specific heat capacity and can provide more heat for water evaporation.

[0067] The aforementioned spray drying device for yeast dehydration using water vapor as a medium, by incorporating a steam generator, connects the steam generated by the generator to the hot air inlet of the spray dryer. By using water vapor instead of traditional air as the drying medium, and leveraging the high specific heat capacity and latent heat of water vapor, drying efficiency and thermal efficiency are improved, resulting in relatively low energy consumption. Furthermore, by using water vapor as the medium, the temperature of the water vapor can be directly controlled by adjusting the pressure. In this case, the control system mainly consists of a steam generator, a pressure regulating valve, and a pressure sensor. The steam generator produces water vapor, and the pressure regulating valve precisely controls the pressure of the water vapor by changing its opening, thereby controlling the temperature. The pressure sensor monitors the pressure in real time and feeds it back to the control system to ensure the stability of the water vapor pressure and temperature. Since the pressure and temperature of saturated water vapor correspond one-to-one, this control method is simple and effective. In contrast, the temperature control system of a conventional spray dryer requires multiple devices to work together, while the water vapor medium system can control the temperature simply by adjusting the pressure, reducing equipment requirements and simplifying control. Moreover, by incorporating a heat pipe heat exchanger, the heat in the exhaust gas of the spray dryer can be recovered and utilized, further reducing energy consumption.

[0068] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. It should be noted that the terms "in one embodiment," "for example," and "again," etc., in this application are intended to illustrate the application and not to limit it. The above embodiments only illustrate several implementation methods of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A spray drying apparatus for yeast dehydration using steam as a medium, characterized in that, include: A steam generator with a steam outlet for outputting steam; A spray dryer has a material inlet, a material drying outlet, a hot air inlet, and a hot air outlet. The hot air inlet is connected to the steam outlet, and the material drying outlet is equipped with a first discharge valve for unloading the dried material. A cyclone collector, wherein the cyclone collector is connected to the hot air outlet; A heat pipe heat exchanger is installed between the cyclone collector and the hot air outlet, and the heat exchange medium pipeline of the heat pipe heat exchanger is connected to the heating system of the steam generator.

2. The spray drying apparatus according to claim 1, characterized in that, The spray drying device also includes a material tank and a feeding pump, wherein the material tank is connected to the material inlet via the feeding pump.

3. The spray drying apparatus according to claim 1, characterized in that, A filter is also installed between the steam outlet of the steam generator and the hot air inlet of the spray dryer.

4. The spray drying apparatus according to claim 1, characterized in that, The cyclone collector has a gas outlet, a main ash discharge outlet and an auxiliary ash discharge port. The gas outlet is equipped with a tail gas condenser and a tail gas filter. The main ash discharge outlet is equipped with a second discharge valve. The auxiliary ash discharge port is equipped with an airlock discharge valve.

5. The spray drying apparatus according to claim 4, characterized in that, The drying tower of the spray dryer has multiple atomization layers.

6. The spray drying apparatus according to claim 5, characterized in that, The drying tower of the spray dryer has 2-4 atomization layers.

7. The spray drying apparatus according to claim 6, characterized in that, The drying tower of the spray dryer is made of stainless steel.

8. The spray drying apparatus according to claim 1, characterized in that, A preheating water tank is added before the water inlet of the steam generator. A heat pipe condenser coil is installed in the preheating water tank. The heat pipe condenser coil is connected to the heat exchange medium pipeline of the heat pipe heat exchanger.

9. The spray drying apparatus according to claim 1, characterized in that, The steam generator has a water preheating chamber, in which a heat pipe condenser coil is arranged, and the heat pipe condenser coil is connected to the heat exchange medium pipeline of the heat pipe heat exchanger.

10. The spray drying apparatus according to any one of claims 1 to 9, characterized in that, The steam generator is equipped with a pressure regulating valve and a pressure sensor.

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