Low-temperature concentration device for processing birch juice

Abstract

The utility model belongs to the technical field of low-temperature concentration, and particularly relates to a low-temperature concentration device for processing birch juice, which comprises a vacuum concentration unit for evaporating and concentrating birch juice in a low-temperature environment; the raw material storage device is used for storing birch raw material juice; a preheating cavity and a heating source cavity are formed in the preheater; the liquid level sensor is used for monitoring the liquid level of the birch juice in the evaporator; the condenser is used for condensing the steam which is not utilized by the heating source cavity into liquid water; the control valves comprise a first control valve mounted on the first ventilation pipeline and a second control valve mounted on the second ventilation pipeline; the controller controls starting and stopping of the first liquid supply pump and the second liquid supply pump according to the liquid level, monitored by the liquid level sensor, of birch juice in the evaporator, and the on-off state of the first control valve and the on-off state of the second control valve and the running state of the condenser are synchronously adjusted. According to the device, the steam flow direction is dynamically switched through the controller according to the liquid level of the evaporator, juice overheating caused by continuous preheating is avoided, and the follow-up evaporation load is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of low-temperature concentration technology, specifically relating to a low-temperature concentration device for birch sap processing. Background Technology

[0002] Birch sap is rich in sugars (mainly sucrose, glucose, and fructose), amino acids, minerals, and bioactive components (such as phenols and flavonoids), possessing extremely high nutritional value and health benefits. Low-temperature concentration is a processing technique that removes moisture while retaining nutrients at lower temperatures (usually <60°C), avoiding the degradation of heat-sensitive substances (such as vitamins and aroma components) caused by high temperatures. By lowering the boiling point of birch sap through heating or vacuum reduction, water escapes as vapor, increasing the solute concentration. Low-temperature concentration avoids the destruction of active ingredients in birch sap by high temperatures, reducing the Maillard reaction (non-enzymatic browning) and the loss of volatile aroma components.

[0003] In existing birch sap low-temperature concentration devices, the generated steam is used to preheat the birch sap to be concentrated. However, since the evaporation rate of vacuum concentration equipment (such as falling film evaporators) is usually 50-200 kg / h, the birch sap to be concentrated may only need to be replenished once every few hours. Since the temperature of steam is usually 45-50°C, assuming the birch sap to be concentrated is 4°C (after refrigeration), it only takes a few minutes to heat the birch sap to be concentrated to about 30°C. Therefore, if steam is only used to preheat the birch sap to be concentrated, it may lead to over-preheating (the sap temperature exceeds the target value, such as >30°C), which will increase the subsequent evaporation load. In addition, long-term preheating may accelerate the loss of certain heat-sensitive components (such as volatile aroma substances). Utility Model Content

[0004] To address the above problems, the purpose of this utility model is to provide a low-temperature concentration device for birch sap processing, thereby solving the problems mentioned in the background art.

[0005] This utility model provides a low-temperature concentration device for birch sap processing, including a vacuum concentration unit comprising an evaporator and a vacuum pump connected to the evaporator via a pipeline, for evaporating and concentrating birch sap at low temperatures; a raw material storage container for storing the birch sap to be concentrated; a preheater having a preheating chamber and a heating source chamber, wherein the inlet of the preheating chamber is connected to the outlet of the raw material storage container via a first liquid supply pump, and the outlet is connected to the inlet of the evaporator via a second liquid supply pump; the steam inlet of the heating source chamber is connected to the steam outlet of the evaporator via a first vent pipe for recovering secondary steam generated by the evaporator as a preheating source; and a liquid level sensor. The following components are installed on the evaporator for real-time monitoring of the birch sap level within the evaporator: a condenser, whose inlet is connected to the first vent pipe via a second vent pipe, for condensing the remaining steam not utilized by the heating source chamber into liquid water; a control valve, including a first control valve installed on the first vent pipe and a second control valve installed on the second vent pipe, for switching the steam flow direction; and a controller, electrically connected to the level sensor, for controlling the start and stop of the first and second liquid supply pumps, synchronously adjusting the on / off states of the first and second control valves, and controlling the operating state of the condenser based on the birch sap level monitored by the level sensor.

[0006] Preferably, when the level sensor detects that the birch sap level is lower than the set lower limit value L1, the first control valve is opened, the second control valve is closed, and the first and second supply pumps are turned on; when the level is higher than the set upper limit value L2, the first control valve is closed, the second control valve is opened, and the first and second supply pumps are turned off.

[0007] Preferably, the device further includes a first temperature sensor, a second temperature sensor, and a third temperature sensor; the first temperature sensor is installed on the preheater and is used to monitor the temperature of the birch sap to be concentrated in the preheater in real time; the second temperature sensor is installed on the first vent pipe and is used to monitor the temperature of the birch sap to be concentrated entering the evaporator in real time; the third temperature sensor is installed on the evaporator and is used to monitor the temperature of the birch sap in the evaporator in real time; the controller adjusts the opening of the first control valve according to the preheating chamber temperature monitored by the first temperature sensor to control the steam flow rate entering the heating source chamber, and dynamically adjusts the heating power of the evaporator according to the temperature difference monitored by the second and third temperature sensors.

[0008] Preferably, the condenser includes a steam passage with its inlet connected to the second vent pipe, and an outlet for discharging condensate is provided opposite to the inlet, for allowing steam to be passed along the second vent pipe into the steam passage for cooling and liquefaction; and two cooling chambers, located on both sides of the steam passage, for connecting to a circulating cooling system to provide a cooling medium for the steam.

[0009] Preferably, multiple baffles are evenly distributed inside the heating source cavity. Two adjacent baffles form a flow channel with the outer wall of the preheating cavity and the inner wall of the heating source cavity. This flow channel is used to divert and guide the steam to achieve uniform heating of the birch sap to be concentrated.

[0010] Preferably, it also includes a cleaning component disposed on the top of the preheater for cleaning residues remaining inside the flow channels. The cleaning component includes a liquid guide tube designed in a ring shape and connected to an external liquid supply device. Its bottom has the same number of cleaning heads as the flow channels. Each of the cleaning heads extends into each flow channel for cleaning residues remaining inside the flow channels.

[0011] The beneficial effects of this utility model are: by controlling the steam flow direction (second control valve), liquid supply pump (second liquid supply pump), and condenser in conjunction with the controller, intelligent distribution of steam is achieved when the evaporation rate and preheating demand change dynamically.

[0012] 1. Solve the problem of overheating:

[0013] Existing technologies often result in juice temperatures exceeding 30°C due to a mismatch between evaporation rate and preheating time. This device uses a controller to dynamically switch the steam flow direction based on the evaporator liquid level, avoiding overheating of the juice caused by continuous preheating and reducing subsequent evaporation load.

[0014] 2. Reduce the loss of heat-sensitive components:

[0015] Existing technologies involve prolonged preheating, which accelerates the loss of volatile aroma compounds. This device utilizes intermittent steam to shorten the time the juice is exposed to high-temperature steam, thus retaining more aroma components. Attached Figure Description

[0016] Figure 1 This is a first three-dimensional structural diagram of the present invention;

[0017] Figure 2 This is a front view structural diagram of the present utility model;

[0018] Figure 3 This is a top view of the structure of this utility model;

[0019] Figure 4 This is a bottom-view cross-sectional structural diagram of the present invention;

[0020] Figure 5 This is a schematic diagram of the first side cross-sectional structure of the present invention;

[0021] Figure 6 This is a schematic diagram of the second side cross-sectional structure of the present invention;

[0022] Figure 7This is a top view cross-sectional structural diagram of the present invention;

[0023] Figure 8 This is a structural schematic diagram of the third side cross-section of this utility model.

[0024] In the diagram: 1. Vacuum concentration unit; 2. Evaporator; 3. Raw material storage tank; 4. Preheater; 5. Preheating chamber; 6. Heating source chamber; 7. First liquid supply pump; 8. Second liquid supply pump; 9. First vent pipe; 10. Liquid level sensor; 11. Condenser; 12. Second vent pipe; 13. First control valve; 14. Second control valve; 15. First temperature sensor; 16. Second temperature sensor; 17. Third temperature sensor; 18. Steam passage; 19. Cooling chamber; 20. Cooling pipe; 21. Baffle; 22. Guide channel; 23. Liquid guide pipe; 24. Cleaning head. Detailed Implementation

[0025] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be described in detail below with reference to the accompanying drawings. The description in this part is only exemplary and explanatory, and should not be used to limit the scope of protection of this utility model in any way.

[0026] like Figure 1-8 As shown, a low-temperature concentration device for birch sap processing includes components such as a vacuum concentration unit 1, a raw material storage tank 3, a preheater 4, a condenser 11, and a controller. The vacuum concentration unit 1 includes an evaporator 2 and a vacuum pump connected to the evaporator 2 via a pipeline. An external heater for the evaporator 2 can be used to heat the birch sap. The vacuum pump (typically a water ring vacuum pump with a pumping speed of 100-500 m³ / h)... 3 / h), maintaining the pressure inside evaporator 2 ≤10kPa and the boiling point reduced to 45-50℃, used to evaporate and concentrate birch sap at low temperature; raw material storage tank 3 is used to store the birch raw material sap to be concentrated; the preheater 4 has a preheating chamber 5 and a heating source chamber 6 inside, the inlet of the preheating chamber 5 is connected to the outlet of the raw material storage tank 3 through the first liquid supply pump 7, and the outlet is connected to the inlet of evaporator 2 through the second liquid supply pump 8; the steam inlet of the heating source chamber 6 is connected to the steam outlet of evaporator 2 through the first vent pipe 9, used to recover the secondary steam generated by evaporator 2 as a preheating source; the condenser 11, its air inlet is connected to the first vent pipe 9 through the second vent pipe 1 The condenser 11 is connected to the second vent pipe 12 and is used to condense the remaining steam that is not used by the heating source chamber 6 into liquid water. Specifically, the condenser 11 includes a steam channel 18, the inlet of which is connected to the second vent pipe 12, and an outlet for discharging condensate is provided opposite to the inlet. The steam is then introduced into the steam channel 18 along the second vent pipe 12 for cooling and liquefaction. There are two cooling chambers 19, located on both sides of the steam channel 18, which are connected to the circulating cooling system (including a circulating pump, delivery pipe, refrigeration equipment, and a tank for storing coolant, all of which are prior art well known to those skilled in the art and will not be described in detail here) to provide a cooling medium for the steam. When the steam flows along the second vent pipe 12... When the gas pipe 12 enters the steam passage 18, coolant is introduced into the wavy cooling pipe 20 inside the cooling chamber 19. The coolant carries away the heat from the walls of the cooling chamber 19, cooling the steam and liquefying it. In addition, a liquid level sensor 10 is installed on the evaporator 2 to monitor the birch sap level in the evaporator 2 in real time. A first control valve 13 is installed on the first vent pipe 9, and a second control valve 14 is installed on the second vent pipe 12 to switch the steam flow direction. The controller is electrically connected to the liquid level sensor 10 to control the first liquid supply pump 7 and the second liquid supply pump 8 based on the birch sap level monitored by the liquid level sensor 10. The starting and stopping of the liquid supply pump 8, the synchronous adjustment of the on / off states of the first control valve 13 and the second control valve 14, and the control of the operating state of the condenser 11 are all controlled. Specifically, when the liquid level sensor 10 detects that the birch sap level is lower than the set lower limit value L1, it indicates that the birch sap concentrate in the evaporator 2 is about to drop to a safe value. At this time, the first control valve 13 is opened, the second control valve 14 is closed, and the first liquid supply pump 7 and the second liquid supply pump 8 are turned on. This allows the birch sap to be concentrated in the raw material storage tank 3 to enter the preheating chamber 5 of the preheater 4 under the action of the first liquid supply pump 7. At the same time, the steam in the evaporator 2 enters the heating source chamber 6 along the first vent pipe 9 as a preheating source for the preheating of the birch sap. Figure 4As shown, in order to improve the efficiency of birch sap preheating, multiple baffles 21 are evenly distributed in the heating source cavity 6. Two adjacent baffles 21 form a flow channel 22 with the outer wall of the preheating cavity 5 and the inner wall of the heating source cavity 6. The flow channel 22 is used to divert and guide the steam to achieve uniform heating of the birch sap to be concentrated. When the liquid level is higher than the set upper limit value L2, it indicates that the birch sap has been replenished. At this time, the first control valve 13 is closed, the second control valve 14 is opened, and the first liquid supply pump 7 and the second liquid supply pump 8 are closed to stop the delivery of the birch sap to be concentrated to the preheater 4. The flow direction of the steam is switched, and the steam enters the condenser 11 along the second vent pipe 12 for cooling and liquefaction, so as to avoid the sap overheating caused by continuous preheating and reduce the subsequent evaporation load.

[0027] Furthermore, such as Figure 3As shown, to achieve precise temperature control and avoid temperature fluctuations caused by single liquid level control, a first temperature sensor 15, a second temperature sensor 16, and a third temperature sensor 17 are installed. All three sensors (e.g., PT100 sensors) must cover temperatures from -20℃ to 100℃, covering the evaporation temperature of 45-60℃ for low-temperature concentration and the 4-30℃ preheating stage, with an accuracy requirement within ±0.5℃, ensuring a temperature control accuracy of ≤±1℃. The parts in contact with birch sap must be made of 316L stainless steel or have a food-grade PTFE coating to prevent corrosion and contamination. The first temperature sensor 15 is installed on the preheater 4 to monitor the temperature of the birch sap to be concentrated in the preheater 4 in real time. The second temperature sensor 16 is installed on... The first vent pipe 9 is used to monitor the temperature of the birch sap to be concentrated entering the evaporator 2 in real time; the third temperature sensor 17 is installed on the evaporator 2 to monitor the temperature of the birch sap inside the evaporator 2 in real time; the controller adjusts the opening of the first control valve 13 according to the temperature of the preheating chamber 5 monitored by the first temperature sensor 15 to control the steam flow rate entering the heating source chamber 6. For example, when the first temperature sensor 15 detects that the temperature of the birch sap to be concentrated in the preheating chamber 5 has reached the preset temperature value, the first control valve 13 is closed to stop the supply of steam to the heating source chamber 6; at the same time, the heating power of the evaporator 2 is dynamically adjusted according to the temperature difference monitored by the second temperature sensor 16 and the third temperature sensor 17. For example, when the first temperature sensor 15 monitors the temperature of the preheated original liquid (T1), the error is ≤ ±0.5℃. The second temperature sensor 16 monitors the temperature (T2) of the preheated stock solution before it enters the concentration tank, with an error ≤ ±0.5℃; the third temperature sensor 17 monitors the temperature (T3) of the heating medium (such as hot water or steam), with an error ≤ ±1℃. The temperature of the birch sap in the concentration tank needs to be maintained at 45-50℃ (the upper limit of low-temperature concentration to avoid degradation of heat-sensitive substances). If T2 < 40℃, the temperature of the heating medium (T3) is increased to 55-60℃ to accelerate the heating; if T2 > 45℃, T3 is decreased to 45-50℃ to prevent overheating. For example, when T2 = 38℃, the PID controller increases T3 from 50℃ to 58℃ until T2 stabilizes at 42℃.

[0028] Furthermore, such as Figure 4-5As shown, in order to facilitate cleaning of the guide channel 22 and avoid clogging, a cleaning assembly is installed on the top of the preheater 4 to clean the residue inside the guide channel 22. The cleaning assembly includes a liquid guide pipe 23, which is designed in a ring shape and connected to an external liquid supply device (including a tank for storing cleaning liquid and a pump body. The tank is connected to the liquid guide pipe 23 through a pipeline, and the inlet and outlet of the pump body are connected to the pipeline to transport the cleaning liquid in the tank to the liquid guide pipe 23). The bottom of the assembly has the same number of cleaning heads 24 as the guide channel 22. Each cleaning head 24 extends into each guide channel 22 to clean the residue inside the guide channel 22.

[0029] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0030] This article uses specific examples to illustrate the principles and implementation methods of this utility model. The above examples are only for the purpose of helping to understand the method and core ideas of this utility model. The above description is only a preferred embodiment of this utility model. It should be noted that due to the limitations of textual expression, there are objectively infinite specific structures. For those skilled in the art, several improvements, modifications, or changes can be made without departing from the principles of this utility model, and the above technical features can also be combined in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the protection scope of this utility model.

Claims

1. A low-temperature concentration device for birch sap processing, characterized by, include: The vacuum concentration unit (1) includes an evaporator (2) and a vacuum pump connected to the evaporator (2) via a pipeline, for evaporating and concentrating birch sap at low temperature. Raw material storage container (3) is used to store birch raw material sap to be concentrated; The preheater (4) has a preheating chamber (5) and a heating source chamber (6) inside. The inlet of the preheating chamber (5) is connected to the outlet of the raw material storage tank (3) through a first liquid supply pump (7), and the outlet is connected to the inlet of the evaporator (2) through a second liquid supply pump (8). The steam inlet of the heating source chamber (6) is connected to the steam outlet of the evaporator (2) through a first vent pipe (9) to recover the secondary steam generated by the evaporator (2) as a preheating source. A liquid level sensor (10) is installed on the evaporator (2) to monitor the level of birch sap in the evaporator (2) in real time; The condenser (11) has its air inlet connected to the first ventilation pipe (9) through the second ventilation pipe (12) and is used to condense the remaining steam that is not used by the heating source chamber (6) into liquid water. The control valves include a first control valve (13) installed on the first vent line (9) and a second control valve (14) installed on the second vent line (12), for switching the direction of steam flow; The controller is electrically connected to the liquid level sensor (10) and is used to control the start and stop of the first liquid supply pump (7) and the second liquid supply pump (8) according to the liquid level of birch sap in the evaporator (2) monitored by the liquid level sensor (10), to synchronously adjust the on / off state of the first control valve (13) and the second control valve (14), and to control the operating state of the condenser (11).

2. The low-temperature concentration device for birch sap processing according to claim 1, characterized in that: When the level sensor (10) detects that the birch sap level is lower than the set lower limit value L1, it opens the first control valve (13), closes the second control valve (14), and turns on the first liquid supply pump (7) and the second liquid supply pump (8); when the level is higher than the set upper limit value L2, it closes the first control valve (13), opens the second control valve (14), and turns off the first liquid supply pump (7) and the second liquid supply pump (8).

3. The low-temperature concentration apparatus for birch sap processing according to claim 1, characterized in that: It also includes a first temperature sensor (15), a second temperature sensor (16) and a third temperature sensor (17); The first temperature sensor (15) is installed on the preheater (4) to monitor the temperature of the birch sap to be concentrated in the preheater (4) in real time. The second temperature sensor (16) is installed on the first ventilation pipe (9) to monitor the temperature of the birch sap to be concentrated in the evaporator (2) in real time. The third temperature sensor (17) is installed on the evaporator (2) to monitor the temperature of the birch sap inside the evaporator (2) in real time; The controller adjusts the opening of the first control valve (13) according to the temperature of the preheating chamber (5) monitored by the first temperature sensor (15), controls the steam flow into the heating source chamber (6), and dynamically adjusts the heating power of the evaporator (2) according to the temperature difference monitored by the second temperature sensor (16) and the third temperature sensor (17).

4. The low-temperature concentration device for birch sap processing according to claim 1, characterized in that: The condenser (11) includes: The steam passage (18) has its inlet connected to the second vent pipe (12), and an outlet for discharging condensate is provided at the position opposite to the inlet. Steam is introduced into the steam passage (18) along the second vent pipe (12) for cooling and liquefaction. The cooling chambers (19) are configured as two, located on both sides of the steam passage (18), and are used to connect with the circulating cooling system to provide cooling medium for the steam.

5. The low temperature concentration device for birch sap processing according to claim 1, characterized in that: Multiple baffles (21) are evenly distributed inside the heating source cavity (6). Two adjacent baffles (21) form a flow channel (22) with the outer wall of the preheating cavity (5) and the inner wall of the heating source cavity (6). The flow channel (22) is used to divert and guide the steam to achieve uniform heating of the birch sap to be concentrated.

6. The low temperature concentration device for birch sap processing according to claim 1, characterized in that: It also includes a cleaning assembly disposed on top of the preheater (4) for cleaning residues remaining inside the flow channel (22), the cleaning assembly comprising: The liquid guide tube (23) is designed in a ring shape and connected to an external liquid supply device. Its bottom has the same number of cleaning heads (24) as the flow guide channel (22). Each of the cleaning heads (24) extends into each of the flow channels (22) to clean the residue remaining in the flow channels (22).

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