Sound pressure thermal composite sterilization equipment for flexibly packaged food

Abstract

The invention discloses sound pressure thermal composite sterilization equipment for soft package food, which relates to the technical field of food sterilization and comprises a tank body, an ultrasonic transducer, an ultrasonic sensor, a heat tracing band and a control unit. The tank body has an inner cavity. The tank body is provided with a compressed air inlet, a compressed air outlet, a water inlet, a water outlet and a feed port, and an upper cover is mounted at the feed port. The ultrasonic transducer is used for emitting ultrasonic waves into the inner cavity. The ultrasonic transducers are arranged in pairs, and the positions of the two ultrasonic transducers in each pair are opposite to each other. The ultrasonic sensor is used for monitoring the energy and waveform of ultrasonic waves in the ultrasonic wave superposition area. The multiple ultrasonic sensors are used for monitoring the ultrasonic wave superposition areas respectively. The heat tracing band is used for preserving heat of the tank body. The control unit is electrically connected with the ultrasonic transducer so as to adjust the power and the phase of the ultrasonic transducer. According to the sterilization equipment, the sterilization temperature of the flexibly packaged food can be reduced while the sterilization effect is ensured, so that the taste and the nutritional value of the food are ensured.

Description

Technical Field

[0001] The invention relates to the technical field of food sterilization, in particular to a sound pressure heat composite sterilization device for soft packaged food. Background Art

[0002] High-temperature sterilizer is one of the mainstream sterilization equipment for soft-packaged food. The standard sterilization temperature of the sterilizer is 121℃, which can ensure the killing of most microorganisms including heat-resistant spores. However, the high-temperature sterilization of the sterilizer may affect the nutritional content and flavor of the food, bringing the risk of over-sterilization to the food. Summary of the invention

[0003] The purpose of the present invention is to provide a sound pressure heat composite sterilization device for soft packaged food, which can reduce the sterilization temperature of soft packaged food while ensuring the sterilization effect.

[0004] To achieve the above object, the present invention provides the following solutions: The invention discloses a sound pressure heat composite sterilization device for soft packaged food, comprising: A tank body, the tank body having an inner cavity for accommodating soft-packaged food; the tank body is provided with a compressed air inlet, a compressed air outlet, a water inlet, a water outlet and a feed inlet, and an upper cover is installed at the feed inlet; An ultrasonic transducer, the ultrasonic transducer being fixed on the outer wall of the tank body and used for emitting ultrasonic waves into the inner cavity; the ultrasonic transducers are arranged in pairs, and the two ultrasonic transducers in each pair are positioned opposite to each other, so as to form an ultrasonic superposition area in the inner cavity between the two ultrasonic transducers; An ultrasonic sensor, the ultrasonic sensor being fixed inside the tank body and used for monitoring the energy and waveform of the ultrasonic wave in the ultrasonic wave superposition area; the number of the ultrasonic sensors is multiple, so as to monitor each of the ultrasonic wave superposition areas respectively; A heating belt, which is fixed to the outer wall of the tank body and is used to keep the tank body warm; A control unit, the control unit is electrically connected to the ultrasonic sensor to obtain the energy and waveform of the ultrasonic wave in the ultrasonic superposition area; the control unit is electrically connected to the ultrasonic transducer to adjust the power and phase of the ultrasonic transducer; The control unit adjusts the power of the ultrasonic transducer by comparing the ultrasonic energy in the ultrasonic superposition area with its own preset energy threshold, and when the energy threshold is exceeded, adjusting the power of a pair of ultrasonic transducers corresponding to the ultrasonic superposition area so that the ultrasonic energy in the ultrasonic superposition area no longer exceeds the energy threshold; The control unit adjusts the phase of the ultrasonic transducer in such a manner that, in the ultrasonic superposition region, a node of an ultrasonic wave of one ultrasonic transducer overlaps an antinode of another ultrasonic wave.

[0005] Preferably, the tank body is further provided with a steam inlet, and the steam inlet is used to introduce hot steam into the inner cavity.

[0006] Preferably, the acoustic pressure and thermal composite sterilization equipment for soft-packaged food also includes a temperature sensor, which is fixed on the tank body and is used to monitor the temperature of the inner cavity; the temperature sensor is electrically connected to the control unit and is used to transmit temperature information to the control unit; a steam regulating valve is installed at the steam inlet to control the supply of steam; the control unit is electrically connected to the steam regulating valve to control the opening and closing of the steam regulating valve.

[0007] Preferably, a pressure reducing valve is installed at the compressed air inlet to reduce the pressure of the compressed air delivered to the inner cavity.

[0008] Preferably, a back pressure valve is installed at the compressed air outlet to maintain the pressure in the inner cavity below a preset pressure.

[0009] Preferably, a water inlet butterfly valve is installed at the water inlet to control the supply of water flow; and a water outlet butterfly valve is installed at the water outlet to control the discharge of water flow.

[0010] Preferably, the acoustic pressure and thermal composite sterilization equipment for soft-packaged food further comprises reinforcing ribs, which surround the side of the can body to limit the outer diameter of the can body.

[0011] Preferably, the heating belt is annular and surrounds the side of the tank body.

[0012] Preferably, the number of the heating tape and the number of the reinforcing ribs are both plural, and the heating tape and the reinforcing ribs are alternately arranged in the up and down directions.

[0013] Preferably, the tank body is a cubic structure, and the ultrasonic transducers distributed in a rectangular array are arranged on the four sides of the tank body.

[0014] Compared with the related art, the present invention has achieved the following technical effects: Compared with conventional high-temperature sterilization equipment, the present invention provides ultrasonic assisted sterilization through an ultrasonic transducer and compressed air assisted sterilization through an air inlet, thereby reducing the temperature requirement of the sterilization process, enabling soft-packaged food to be sterilized at a lower temperature, thereby helping to maintain the taste and nutritional value of the food.

[0015] Compared with the conventional ultrasonic sterilization method of setting a single probe-type ultrasonic transducer, the ultrasonic transducer in the present invention is installed in a wall-mounted manner, and the ultrasonic transducers are arranged in pairs, and the positions of the two ultrasonic transducers in each pair are directly opposite, so that an ultrasonic superposition area is formed in the inner cavity between the two ultrasonic transducers. Under the control of the control unit on the phase of the ultrasonic transducer, in the ultrasonic superposition area, the node of the ultrasonic wave of one ultrasonic transducer overlaps with the antinode of the other ultrasonic wave, so that the node positions of the two ultrasonic waves have a certain ultrasonic energy, thereby improving the sterilization effect of the ultrasonic node position.

[0016] Compared with the conventional ultrasonic sterilization method without ultrasonic sensors, the present invention combines multiple ultrasonic sensors to monitor multiple ultrasonic superposition areas respectively, and controls the power of the ultrasonic transducer through the control unit, so as to adjust the energy distribution of the ultrasonic wave in the inner cavity of the tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a schematic diagram of a sound pressure heat composite sterilization device for soft packaged food according to an embodiment of the present invention; Figure 2 This is the working principle diagram of the control unit.

[0019] In the figure: 1-tank body; 11-feed port; 12-ultrasonic transducer; 13-heating belt; 14-reinforcement rib; 15-temperature sensor; 16-pressure sensor; 17-ultrasonic sensor; 2-compressed air inlet; 21-pressure reducing valve; 3-compressed air outlet; 31-back pressure valve; 4-steam inlet; 41-steam regulating valve; 5-water inlet; 51-water inlet butterfly valve; 6-water outlet; 61-water outlet butterfly valve; 7-control unit; 71-low-pass digital filter; 72-PID temperature control module; 73-threshold control module. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] The purpose of the present invention is to provide a sound pressure heat composite sterilization device for soft packaged food, which can reduce the sterilization temperature of soft packaged food while ensuring the sterilization effect.

[0022] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] Reference Figure 1 , Figure 2 This embodiment provides an acoustic pressure and thermal composite sterilization device for soft-packaged food (hereinafter referred to as the sterilization device), including a tank body 1, an ultrasonic transducer 12, an ultrasonic sensor 17, a heating belt 13 and a control unit 7.

[0024] The tank body 1 has an inner cavity for accommodating soft-packaged food. The tank body 1 is provided with a compressed air inlet 2, a compressed air outlet 3, a water inlet 5, a water outlet 6 and a feed inlet 11, and an upper cover is installed at the feed inlet 11. The ultrasonic transducer 12 is fixed on the outer wall of the tank body 1 (i.e., wall-mounted), and is used to emit ultrasonic waves into the inner cavity. The ultrasonic transducers 12 are arranged in pairs, and the positions of the two ultrasonic transducers 12 in each pair are directly opposite to form an ultrasonic superposition area in the inner cavity between the two ultrasonic transducers 12. The ultrasonic sensor 17 is fixed on the outer wall of the tank body 1 to monitor the energy and waveform of the ultrasonic wave in the ultrasonic superposition area. The number of ultrasonic sensors 17 is multiple to monitor each ultrasonic superposition area separately. The heating belt 13 is fixed on the outer wall of the tank body 1 to keep the tank body 1 warm. The control unit 7 is electrically connected to the ultrasonic sensor 17 to obtain the energy and waveform of the ultrasonic wave in the ultrasonic superposition area. The control unit 7 is electrically connected to the ultrasonic transducer 12 to adjust the power and phase of the ultrasonic transducer 12.

[0025] Among them, the control unit 7 adjusts the power of the ultrasonic transducer 12 by comparing the ultrasonic energy in the ultrasonic superposition area with its own preset energy threshold. When the energy threshold is exceeded, the power of a pair of ultrasonic transducers 12 corresponding to the ultrasonic superposition area is adjusted so that the ultrasonic energy in the ultrasonic superposition area no longer exceeds the energy threshold.

[0026] The energy threshold may be only a minimum energy threshold, in which case the ultrasonic energy may be dynamically maintained above the minimum energy threshold.

[0027] The energy threshold may also include a minimum energy threshold and a maximum energy threshold at the same time, in which case the ultrasonic energy may be dynamically maintained between the minimum energy threshold and the maximum energy threshold.

[0028] The control unit 7 adjusts the phase of the ultrasonic transducer 12 in such a way that, in the ultrasonic superposition region, the node of the ultrasonic wave of one ultrasonic transducer 12 overlaps the antinode of the ultrasonic wave of another ultrasonic wave.

[0029] The working principle of the sterilization equipment in this embodiment is as follows: Compared with conventional high-temperature sterilization equipment, this embodiment uses ultrasonic wave-assisted sterilization provided by the ultrasonic transducer 12 and compressed air assisted sterilization introduced into the inner cavity through the compressed air inlet 2, thereby reducing the temperature requirement of the sterilization process, so that soft-packaged food can achieve the sterilization effect at a lower temperature (65°C~95°C), which helps to maintain the taste and nutritional value of the food.

[0030] Compared with the conventional ultrasonic sterilization method of setting a single probe-type ultrasonic transducer, the ultrasonic transducer in this embodiment is installed in a wall-mounted manner, and the ultrasonic transducers 12 are arranged in pairs, and the positions of the two ultrasonic transducers 12 in each pair are directly opposite, so that an ultrasonic superposition area is formed in the inner cavity between the two ultrasonic transducers 12. Under the control of the control unit 7 on the phase of the ultrasonic transducer 12, in the ultrasonic superposition area, the node of the ultrasonic wave of one ultrasonic transducer 12 overlaps with the antinode of the other ultrasonic wave, so that the node positions of the two ultrasonic waves have a certain ultrasonic energy, thereby improving the sterilization effect of the ultrasonic node position.

[0031] Compared with the conventional ultrasonic sterilization method without an ultrasonic sensor 17, this embodiment combines multiple ultrasonic sensors 17 to monitor multiple ultrasonic superposition areas respectively, and controls the power of the ultrasonic transducer 12 through the control unit 7, so as to adjust the energy distribution of the ultrasonic wave in the inner cavity of the tank body 1.

[0032] The specific way in which the control unit 7 adjusts the power of the ultrasonic transducer 12 may be to make the ultrasonic energy evenly distributed in the inner cavity of the can body 1, which is suitable for the case where the microorganisms are evenly distributed on the surface of the soft-packaged food. In this case, the energy thresholds of each ultrasonic superposition area are consistent.

[0033] The specific way in which the control unit 7 adjusts the power of the ultrasonic transducer 12 is to increase the local ultrasonic energy, which is applicable to the case where microorganisms are enriched in a part of the soft-packaged food (such as the bag mouth). In this case, the energy threshold of the ultrasonic superposition area for key sterilization is higher than that of other areas.

[0034] As a possible example, in this embodiment, a steam inlet 4 is also provided on the tank body 1, and the steam inlet 4 is used to introduce hot steam into the inner cavity. It should be noted that although the heating belt 13 can heat and keep the tank body 1 warm, its heating speed is slow. When a larger soft-packaged food enters the cavity, the soft-packaged food absorbs the heat of the water in the cavity, causing the water to cool down rapidly. If the water is heated only by the heating belt 13, it will take a long time to wait, reducing the sterilization efficiency. In this embodiment, a steam inlet is provided on the tank body 1. After the soft-packaged food enters the cavity, heat can be quickly supplied by direct steam injection, so that the temperature in the cavity quickly returns to the required sterilization temperature, thereby improving the sterilization efficiency.

[0035] As a possible example, in this embodiment, the sterilization device further includes a temperature sensor 15, which is fixed to the tank body 1 and is used to monitor the temperature of the inner cavity. The temperature sensor 15 is electrically connected to the control unit 7 and is used to transmit temperature information to the control unit 7. A steam regulating valve 41 is installed at the steam inlet 4 to control the supply of steam. The control unit 7 is electrically connected to the steam regulating valve 41 to control the opening and closing of the steam regulating valve 41.

[0036] Exemplarily, there are multiple temperature sensors 15 to monitor the temperature of different areas in the inner cavity. The control unit 7 is provided with a low-pass digital filter 71 and a PID temperature control module 72. The temperature sensor 15 transmits temperature data to the low-pass digital filter 71, filters the temperature signal, and then inputs it into the PID temperature control module 72. The PID temperature control module 72 outputs a control signal to the steam regulating valve 41 after calculation to control the opening and closing of the steam regulating valve 41. The calculation logic of the PID temperature control module 72 can adopt conventional technical means, which will not be repeated here.

[0037] As a possible example, in this embodiment, a pressure reducing valve 21 is installed at the compressed air inlet 2 to reduce the pressure of the compressed air delivered to the inner cavity.

[0038] As a possible example, in this embodiment, a back pressure valve 31 is installed at the compressed air outlet 3 to maintain the pressure in the inner cavity below a preset pressure.

[0039] As a possible example, in this embodiment, a water inlet butterfly valve 51 is installed at the water inlet 5 to control the supply of water flow, and a water outlet butterfly valve 61 is installed at the water outlet 6 to control the discharge of water flow.

[0040] As a possible example, in this embodiment, the sterilization device further includes a reinforcing rib 14, which surrounds the side of the tank body 1 to limit the outer diameter of the tank body 1. When compressed air enters the inner cavity of the tank body 1 from the compressed air inlet 2, the tank body 1 expands under the action of the internal and external pressure difference. At this time, the reinforcing rib 14 limits the outer dimensions of the tank body 1 to prevent the tank body 1 from bursting.

[0041] As a possible example, in this embodiment, the heating belt 13 is annular, and the heating belt 13 surrounds the side of the tank body 1. By setting the heating belt 13 in annular shape, it is ensured that the side wall of the tank body 1 in the entire circumferential direction can be heated.

[0042] As a possible example, in this embodiment, the number of the heating belt 13 and the reinforcing ribs 14 are both multiple, and the heating belt 13 and the reinforcing ribs 14 are alternately arranged in the vertical direction. With this arrangement, each part of the side wall of the tank body 1 can be strengthened and heated in the entire height direction.

[0043] As a possible example, in this embodiment, the tank body 1 is a cubic structure, and ultrasonic transducers 12 distributed in a rectangular array are arranged on the four sides of the tank body 1. According to different actual needs, those skilled in the art may also select a tank body 1 in the shape of a regular hexagonal prism, a regular octagonal prism, a cylinder, etc., as long as it has opposite sides to install the ultrasonic transducers 12 arranged in pairs.

[0044] Exemplarily, the material of the tank body 1 is food-grade stainless steel, and the pressure resistance of the tank body 1 is not less than 4 bar.

[0045] As a possible example, in this embodiment, the sterilization device also includes a pressure sensor 16, which is fixed on the tank body 1 and is used to monitor the air pressure in the inner cavity of the tank body 1. The pressure sensor 16 is electrically connected to the control unit 7 and is used to transmit pressure information to the control unit 7. When the air pressure in the inner cavity is lower than the pressure threshold preset with the control unit 7, the control unit 7 sends a control signal to the pressure reducing valve 21 to open the pressure reducing valve 21, and the compressed air is passed into the inner cavity of the tank body 1 from the compressed air inlet 2 until the air pressure in the inner cavity is higher than the pressure threshold. Since the back pressure valve 31 can act as a safety valve to a certain extent, the pressure threshold is only a low pressure threshold, and the maximum air pressure in the inner cavity can be controlled by the back pressure valve 31.

[0046] In this embodiment, the control unit 7 is provided with a threshold control module 73. The pressure sensor 16 and the ultrasonic sensor 17 transmit the monitored data to the threshold control module 73. After calculation, the threshold control module 73 issues control instructions to the pressure reducing valve 21 and the ultrasonic transducer 12.

[0047] In summary, the sterilization equipment of this embodiment can monitor the sound field, pressure field and temperature field in different areas of the inner cavity in real time, and make precise adjustments based on the monitoring results.

[0048] The use process of the sterilization equipment is as follows: The soft-packaged food to be sterilized is placed in the hanging net and put into the tank body 1 from the feed inlet 11. The upper end of the hanging net is located outside the feed inlet 11. Water is added through the water inlet 5 until the soft-packaged food to be sterilized is completely immersed. By installing an upper cover at the feed inlet, the upper end of the hanging net is clamped between the feed inlet 11 and the upper cover.

[0049] Open the steam regulating valve 41 to heat the water in the tank to the temperature specified by the process. Open the pressure reducing valve 21, close the back pressure valve 31, and control the pressure in the tank to the pressure specified by the process. Turn on the ultrasonic transducer 12 and start sterilization according to the frequency, waveform and power specified by the process.

[0050] During the sterilization process, the opening of the steam regulating valve 41 and the phase and power of the ultrasonic transducer 12 are automatically adjusted by the control unit 7 according to the real-time temperature and ultrasonic energy distribution in the can obtained by the temperature sensor 15 and the ultrasonic sensor 17, so that the temperature field and ultrasonic field in the can are kept uniform and stable. After the sterilization is completed, the ultrasonic transducer 12, the pressure reducing valve 21 and the steam regulating valve 41 are closed, and the back pressure valve 31 is opened to release the pressure. After the pressure is released, the upper cover is opened, and the sterilized soft-packaged food is lifted out of the can by the hanging net to complete the sterilization process operation.

[0051] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A sound pressure and heat composite sterilization equipment for soft packaged food, characterized in that: include: A tank body, the tank body having an inner cavity for accommodating soft-packaged food; the tank body is provided with a compressed air inlet, a compressed air outlet, a water inlet, a water outlet and a feed inlet, and an upper cover is installed at the feed inlet; An ultrasonic transducer, the ultrasonic transducer being fixed on the outer wall of the tank body and used for emitting ultrasonic waves into the inner cavity; the ultrasonic transducers are arranged in pairs, and the two ultrasonic transducers in each pair are positioned opposite to each other, so as to form an ultrasonic superposition area in the inner cavity between the two ultrasonic transducers; An ultrasonic sensor, the ultrasonic sensor being fixed inside the tank body and used for monitoring the energy and waveform of the ultrasonic wave in the ultrasonic wave superposition area; the number of the ultrasonic sensors is multiple, so as to monitor each of the ultrasonic wave superposition areas respectively; A heating belt, which is fixed to the outer wall of the tank body and is used to keep the tank body warm; A control unit, the control unit is electrically connected to the ultrasonic sensor to obtain the energy and waveform of the ultrasonic wave in the ultrasonic superposition area; the control unit is electrically connected to the ultrasonic transducer to adjust the power and phase of the ultrasonic transducer; The control unit adjusts the power of the ultrasonic transducer by comparing the ultrasonic energy in the ultrasonic superposition area with its own preset energy threshold, and when the energy threshold is exceeded, adjusting the power of a pair of ultrasonic transducers corresponding to the ultrasonic superposition area so that the ultrasonic energy in the ultrasonic superposition area no longer exceeds the energy threshold; The control unit adjusts the phase of the ultrasonic transducer in such a manner that, in the ultrasonic superposition region, a node of an ultrasonic wave of one ultrasonic transducer overlaps an antinode of another ultrasonic wave.

2. The acoustic pressure and heat composite sterilization equipment for soft packaged food according to claim 1, characterized in that: The tank body is also provided with a steam inlet, and the steam inlet is used to introduce hot steam into the inner cavity.

3. The acoustic pressure and heat composite sterilization equipment for soft packaged food according to claim 2, characterized in that: It also includes a temperature sensor, which is fixed on the tank body and is used to monitor the temperature of the inner cavity; the temperature sensor is electrically connected to the control unit and is used to transmit temperature information to the control unit; a steam regulating valve is installed at the steam inlet to control the supply of steam; the control unit is electrically connected to the steam regulating valve to control the opening and closing of the steam regulating valve.

4. The acoustic pressure and heat composite sterilization equipment for soft packaged food according to claim 1, characterized in that: A pressure reducing valve is installed at the compressed air inlet to reduce the pressure of the compressed air delivered to the inner cavity.

5. The acoustic pressure and heat composite sterilization equipment for soft packaged food according to claim 1, characterized in that: A back pressure valve is installed at the compressed air outlet to maintain the pressure in the inner cavity below a preset pressure.

6. The acoustic pressure and heat composite sterilization equipment for soft packaged food according to claim 1, characterized in that: A water inlet butterfly valve is installed at the water inlet to control the supply of water flow; a water outlet butterfly valve is installed at the water outlet to control the discharge of water flow.

7. The acoustic pressure and heat composite sterilization equipment for soft packaged food according to claim 1, characterized in that: The tank also includes reinforcing ribs which surround the side of the tank body to limit the outer diameter of the tank body.

8. The acoustic pressure and heat composite sterilization equipment for soft packaged food according to claim 7, characterized in that: The heating belt is annular and surrounds the side surface of the tank body.

9. The acoustic pressure and heat composite sterilization equipment for soft packaged food according to claim 8, characterized in that: The number of the heating belt and the reinforcing ribs are both plural, and the heating belt and the reinforcing ribs are alternately arranged in the up and down directions.

10. The acoustic pressure and heat composite sterilization equipment for soft packaged food according to claim 1, characterized in that: The tank body is a cubic structure, and the ultrasonic transducers distributed in a rectangular array are arranged on the four sides of the tank body.

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