Fermentation equipment dissolved oxygen control device

Abstract

The utility model discloses a dissolved oxygen control device of fermentation equipment. An oxygen dissolving instrument, a temperature instrument, a PH detector and a liquid level relay are arranged in a fermentation tank; the PLC is in communication connection with the analog quantity input module; the dissolved oxygen meter, the PH detector and the thermometer are respectively connected with the analog quantity input module; the total operation switch, the dissolved oxygen starting and stopping switch, the temperature control starting and stopping switch, the PH control starting and stopping switch, the material supplementing starting and stopping switch, the defoaming starting and stopping switch and the liquid level relay are respectively connected with the input end of the PLC; the steam generator, the steam valve, the hot water valve, the cold water valve, the feeding pump, the alkali liquor valve, the material supplementing valve, the defoaming valve and the stirring motor are connected to the output end of the PLC. And the frequency converter is in communication connection with the PLC through 485. The frequency of the frequency converter is controlled by the PLC, the speed of the stirring motor can be conveniently and quickly regulated according to process requirements, and the dissolved oxygen proportion value can be well controlled.

Description

Technical Field

[0001] The utility model relates to a dissolved oxygen control device for fermentation equipment, belonging to the technical field of fermentation equipment. Background Art

[0002] Dissolved oxygen is a very important parameter in the microbial fermentation process. As the microorganisms continue to ferment, the dissolved oxygen ratio gradually decreases, so it is necessary to increase the stirring speed in the tank to increase the dissolved oxygen ratio. Currently, common fermentation tanks use ordinary motor stirring, which cannot be adjusted in speed and cannot well control the dissolved oxygen ratio value.

[0003] At the same time, the fermentation process also requires process flows such as feeding control, fermentation temperature control, pH control, feeding, and defoaming control.

[0004] With the development of industrial frequency converters, the application scope of frequency converters has gradually become wider. Combining frequency converters with fermentation equipment to develop a new control system to solve the technical problem of dissolved oxygen ratio control in fermentation tanks has broad practical application value. Utility Model Content

[0005] The purpose of the utility model is to provide a dissolved oxygen control device for fermentation equipment, which solves the problem that the common fermentation tanks mentioned in the background art use ordinary motors for stirring, cannot adjust the speed, and cannot well control the dissolved oxygen ratio value.

[0006] The purpose of this utility model is achieved through the following technical solutions:

[0007] A dissolved oxygen control device for fermentation equipment, comprising a PLC, an analog input module, a dissolved oxygen meter, a temperature meter, a pH detector, a main operation switch, a dissolved oxygen start-stop switch, a temperature control start-stop switch, a pH control start-stop switch, a feeding start-stop switch, a defoaming start-stop switch, a liquid level relay, a steam generator, a steam valve, a hot water valve, a cold water valve, a feeding pump, an alkali solution valve, a feeding valve, a defoaming valve, a stirring motor, and a frequency converter; the dissolved oxygen meter, temperature meter, pH detector, and liquid level relay are installed in a fermentation tank; the PLC and the analog input module are connected to each other. The input module is communicated; the dissolved oxygen meter, pH detector, and temperature meter are respectively connected to the analog input module; the main operation switch, dissolved oxygen start-stop switch, temperature control start-stop switch, pH control start-stop switch, feeding start-stop switch, defoaming start-stop switch, and liquid level relay are respectively connected to the input end of the PLC, and the steam generator, steam valve, hot water valve, cold water valve, feeding pump, alkali solution valve, feeding valve, defoaming valve, and stirring motor are respectively connected to the output end of the PLC; the frequency converter and PLC are connected via 485 communication.

[0008] The purpose of this utility model can be further achieved by the following technical measures:

[0009] The aforementioned dissolved oxygen control device for fermentation equipment further includes a proximity switch, which is installed on the stirring motor; the proximity switch is connected to the input end of the PLC, and the model of the proximity switch is Autonics PRL18-8DP.

[0010] The aforementioned dissolved oxygen control device for fermentation equipment, wherein the model of the PLC is Siemens CPU ST20, and the model of the analog input module is Siemens 6ES7288-3AE04-0AA0.

[0011] The aforementioned dissolved oxygen control device for fermentation equipment, wherein the model of the dissolved oxygen meter is the LianCe Instrument SIN-DY3000, the model of the pH detector is the LianCe Instrument SIN-DC2000 / 2100, and the model of the temperature transmitter is the LianCe Instrument SIN-P202.

[0012] The aforementioned dissolved oxygen control device for fermentation equipment, wherein the model of the steam generator is LDR54KW.

[0013] The aforementioned dissolved oxygen control device for fermentation equipment, wherein the inverter model is Orei E800-0030T3.

[0014] The aforementioned dissolved oxygen control device for fermentation equipment, wherein the model of the liquid level relay is Chint JYB-714BAC220V.

[0015] Compared with existing technologies, the present invention offers the following advantages: It utilizes a PLC to control the frequency of the inverter, which in turn controls the rotation of the motor, which in turn drives the agitator shaft. This technology utilizes inverter technology to precisely control the speed of dissolved oxygen agitation, allowing for convenient and quick adjustment of the agitator motor speed according to process requirements, effectively controlling the dissolved oxygen ratio. Furthermore, the use of an inverter is more cost-effective than using servo controller technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is the electrical principle diagram of the utility model;

[0017] Figure 2 This is the wiring diagram of the frequency converter of this utility model. DETAILED DESCRIPTION

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0019] like Figure 1As shown, the dissolved oxygen control device of the fermentation equipment of the present invention includes a PLC, an analog input module, a dissolved oxygen meter, a temperature meter, a pH detector, a main operation switch, a dissolved oxygen start-stop switch, a temperature control start-stop switch, a pH control start-stop switch, a feeding start-stop switch, a defoaming start-stop switch, a liquid level relay, a steam generator, a steam valve, a hot water valve, a cold water valve, a feeding pump, an alkali solution valve, a feeding valve, a defoaming valve, a stirring motor, and a frequency converter; the main operation switch, the dissolved oxygen start-stop switch, the temperature control start-stop switch, the pH control start-stop switch, the feeding start-stop switch, and the defoaming start-stop switch are toggle switches.

[0020] The dissolved oxygen meter, temperature meter, pH detector, and liquid level relay are installed in the fermentation tank; the PLC is connected to the analog input module; the dissolved oxygen meter, pH detector, and temperature meter are connected to the analog input module respectively; the main operation switch, dissolved oxygen start-stop switch, temperature control start-stop switch, pH control start-stop switch, feeding start-stop switch, defoaming start-stop switch, and liquid level relay are connected to the input end of the PLC respectively, and the steam generator, steam valve, hot water valve, cold water valve, feeding pump, alkali liquid valve, feeding valve, defoaming valve, and stirring motor are connected to the output end of the PLC respectively; the frequency converter is connected to the PLC via 485 communication. The above components are selected and configured as follows: the PLC model is Siemens CPU ST20, and the analog input module model is Siemens 6ES7288-3AE04-0AA0. The dissolved oxygen meter is a LianCe Instrument SIN-DY3000, the pH meter is a LianCe Instrument SIN-DC2000 / 2100, and the temperature transmitter is a LianCe Instrument SIN-P202. The steam generator is an LDR54KW. The inverter is an Orei E800-0030T3. The liquid level relay is a Chint JYB-714BAC220V.

[0021] The wiring diagram of the PLC and the frequency converter of this utility model is as follows Figure 2 As shown in the figure, the inverter communicates with the PLC through the 485 port. L1, L2, and L3 of the inverter are connected to the power supply respectively, and U, V, and W are connected to the motor. When starting is required, the PLC output terminal outputs a signal to energize the relay KA9, and the relay KA9 contacts are closed, so that the inverter's enable terminal D13 is connected to the common terminal CM, and the inverter starts working.

[0022] To achieve more precise control of the stirring motor speed, the fermentation equipment's dissolved oxygen control device can also be equipped with a proximity switch. The Autonics PRL18-8DP is used. This proximity switch is electrically connected to the input of the PLC and installed on the stirring motor. Each time the motor rotates, the proximity switch sends a pulse signal to the PLC. The PLC determines the motor speed based on the pulse interval and compares the collected speed with the process setpoint. The PLC then controls the inverter frequency to adjust the speed, achieving more precise control of the stirring motor speed.

[0023] The control process of each functional part of the utility model is as follows:

[0024] 1. Dissolved oxygen control:

[0025] (1) The output of the dissolved oxygen meter is connected to the PLC analog input module. The sensor output signal type is 4-20mA, and the actual data value read by the PLC is 5530-27648;

[0026] (2) After calibration by the PLC program, 5530 corresponds to 0% dissolved oxygen content and 27648 corresponds to 100% dissolved oxygen content;

[0027] (3) The current dissolved oxygen percentage can be calculated based on the collected data values;

[0028] (4) Set the default stirring speed and required dissolved oxygen value in advance;

[0029] (5) The inverter output frequency is 0~50HZ, and the corresponding control motor speed is 0~1450rmp / min;

[0030] (6)PLC sends the frequency to the inverter through the 485 communication port;

[0031] (7) First, close the main operation switch to start working and allow other function buttons to be operated;

[0032] (8) Close the dissolved oxygen start-stop switch, the PLC controls the frequency converter to make the motor rotate at the initial speed, and the motor drives the stirring shaft to rotate;

[0033] (9) If the dissolved oxygen value continues to decrease during the fermentation process, the rotation speed should be increased by 10 rpm / min for every 1% decrease;

[0034] (10) If the dissolved oxygen value returns to normal, the default speed will be restored.

[0035] 2. Temperature control

[0036] (1) The output of the temperature meter is connected to the PLC analog input module. The sensor output signal type is 4-20mA. The actual data value read by the PLC is 5530-27648, corresponding to -30-150℃;

[0037] (2) Close the temperature control start-stop switch, and the PLC controls the hot water valve or cold water valve to input cold or hot water according to the current temperature and the set temperature to adjust the temperature;

[0038] (3) The control method can be as follows: according to the temperature difference, the PLC sets the water valve to a control cycle every 30 seconds, the opening time is 10 to 20 seconds, and the water valve is closed for the rest of the time. The periodic adjustment can play a role in fine adjustment and prevent overshoot;

[0039] 3. PH control

[0040] (1) The output of the pH meter is connected to the PLC analog input module. The sensor output signal type is 4-20mA. The actual data value read by the PLC is 5530-27648, corresponding to 0-14;

[0041] (2) Close the pH control start-stop switch, and the PLC controls the alkali solution valve to add alkali solution according to the current pH value and the set pH value;

[0042] (3) The control method can be as follows: according to the pH difference, set the addition valve to a control cycle of every 30 seconds, the opening time is 5-10 seconds, and the lye valve is closed for the rest of the time;

[0043] 4. Feeding Control

[0044] (1) Close the feeding start and stop switch, and the PLC opens and closes the feeding valve according to the set time;

[0045] (2) The control method can be as follows: the entire fermentation process is divided into 5 time periods, and different settings are set according to different fermentation varieties, such as 1-2 hours, 3-4 hours, 5-6 hours, 7-8 hours, and 9-10 hours. 100 mL of feed (microbial strain) is added in each hour period, and an interval feeding method is used, such as feeding for 10 seconds and stopping for 30 seconds;

[0046] 5. Defoaming control

[0047] (1) Continuous stirring during the fermentation process will produce foam. A liquid level relay is installed to detect the liquid level. The monitoring point is higher than the normal liquid level. If foam is generated, the liquid level relay alarm is triggered;

[0048] (2) Close the defoaming start / stop switch. If the liquid level relay alarms, the PLC opens the defoaming valve according to the bubble signal from the liquid level relay and adds defoaming liquid to remove the foam. If the liquid level relay alarm is cleared, the defoaming is stopped.

[0049] In addition to the above embodiments, the present invention may also have other implementation methods. Any technical solutions formed by equivalent replacement or equivalent transformation fall within the protection scope required by the present invention.

Claims

1. A dissolved oxygen control device for fermentation equipment, characterized in that , including PLC, analog input module, dissolved oxygen meter, temperature meter, pH detector, main operation switch, dissolved oxygen start-stop switch, temperature control start-stop switch, pH control start-stop switch, feeding start-stop switch, defoaming start-stop switch, liquid level relay, steam generator, steam valve, hot water valve, cold water valve, feeding pump, alkali solution valve, feeding valve, defoaming valve, stirring motor, frequency converter; the dissolved oxygen meter, temperature meter, pH detector, liquid level relay are installed in the fermentation tank; PLC communicates with analog input module connection; the dissolved oxygen meter, pH detector, and temperature meter are respectively connected to the analog input module; the main operation switch, dissolved oxygen start-stop switch, temperature control start-stop switch, pH control start-stop switch, feeding start-stop switch, defoaming start-stop switch, and liquid level relay are respectively connected to the input end of the PLC, and the steam generator, steam valve, hot water valve, cold water valve, feeding pump, alkali solution valve, feeding valve, defoaming valve, and stirring motor are respectively connected to the output end of the PLC; the frequency converter and PLC are connected via 485 communication.

2. The fermentation equipment dissolved oxygen control device according to claim 1, characterized in that: It also includes a proximity switch, which is installed on the stirring motor; the proximity switch is connected to the input end of the PLC, and the model of the proximity switch is Autonics PRL18-8DP.

3. The fermentation equipment dissolved oxygen control device according to claim 1, characterized in that: The model of PLC is Siemens CPUST20, and the model of analog input module is Siemens 6ES7288-3AE04-0AA0.

4. The dissolved oxygen control device for fermentation equipment according to claim 1, wherein: The model of the dissolved oxygen meter is SIN-DY3000, the model of the pH detector is SIN-DC2000 / 2100, and the model of the temperature transmitter is SIN-P202.

5. The dissolved oxygen control device for fermentation equipment according to claim 1, characterized in that: The model of the steam generator is LDR54KW.

6. The fermentation equipment dissolved oxygen control device according to claim 1, characterized in that: The model of the inverter is Orei E800-0030T3.

7. The fermentation equipment dissolved oxygen control device according to claim 1, characterized in that: The model of the liquid level relay is Chint JYB-714B AC220V.

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