JPH06194345A - Ethanol concentration measuring system - Google Patents

Abstract

PURPOSE:To solve problems in durability, running cost, deterioration of accuracy in measurement, acquisition of ethanol concentration calibration data, etc., by providing a fermenter with a bypath passing through a thermostatic bath and placing a measurement cell incorporating an ultrasonic oscillator and a thermocouple in the thermostatic bath. CONSTITUTION:A fermenter 10 is provided with a bypath, i.e., sampling pipes 1a, 1b, passing through a thermostatic bath 9a in which a measurement cell 5 incorporating an ultrasonic oscillator 4 and a thermocouple 6 is disposed. The pipes 1a, 1b are used for sampling fermentation liquid which is fed from the fermenter 10 to the cell 5 by means of a pump 2. Temperature of the fermentation liquid fed into the cell 5 is measured by means of the thermocouple 6 and ultrasonic wave is sent from the oscillator 4 and reflection wave is received in the cell 5. Transmission wave signal of the oscillator 4 is fed from an operating unit 8 through an amplifier 7 and the operating unit 8 receives a receiving signal from the oscillator 4 and a temperature signal from the thermostat 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for measuring the concentration of ethanol in an ethanol fermentation tank.

[0002]

2. Description of the Related Art There are various methods for measuring the ethanol concentration in an ethanol fermentation tank, including a method of utilizing the molecular recognition function of biological substances, microorganisms, antibodies, cells, etc., and sampling through a porous membrane. There is a method of analyzing the concentration of ethanol in the gas by an infrared gas analyzer, a near infrared method, or the like.

[0003]

However, in the method utilizing the above-mentioned molecular identification function, it is necessary to repeatedly sterilize (heat disinfect) the sensor, which causes a problem in durability and a high running cost. There is a problem of becoming. In addition, regarding the method using an infrared gas analyzer, in addition to the problems of durability and running cost against heat sterilization described above,
There is a problem that the measurement accuracy deteriorates when sugar coexists in the fermentation liquid, or that ethanol concentration calibration data needs to be acquired for each application target. Furthermore, in the near-infrared method, in addition to the problem of obtaining the concentration calibration data described above, it is necessary to remove suspended components such as bacterial cells in the fermentation liquid, and the cost of the entire device and running cost (consumption There is a problem that the electric power) becomes extremely high.

The present invention is a new ethanol concentration measuring apparatus which solves the problems in the above-mentioned methods, namely, durability, running cost, deterioration of measurement accuracy, acquisition of ethanol concentration calibration data, and the cost of the entire apparatus. For the purpose of providing.

[0005]

Means for Solving the Problems The present invention that achieves the above-mentioned object is to provide a pump and a sluice valve provided in a sampling pipe whose both ends are connected to a fermentation tank, and a sampling pipe between the pump and the sluice valve. Measuring cell in which an ultrasonic transducer is placed inside, a thermocouple with one end inserted in the measuring cell, an ethanol concentration calculator connected to the other end of the thermocouple, and this calculator An amplifier connected between the ultrasonic transducer and the ultrasonic transducer, a thermostatic chamber in which the measurement cell is housed and the sampling pipe penetrates, and a cooling / heating device for supplying cold water or hot water into the thermostatic chamber, It is characterized by having.

[0006]

[Function] Since the fermentation tank is provided with a bypass to pass through the inside of the constant temperature tank, a measuring cell is provided in this constant temperature tank, and an ultrasonic vibrator and a thermocouple are provided in the measuring cell, so that the fermentation liquid changes depending on the temperature change. The ethanol concentration is obtained from the relationship between the temperature characteristic of the sound velocity and the ethanol concentration while suppressing the temperature of the bubbles in the inside to improve the accuracy.

[0007]

EXAMPLE An example of the present invention will now be described with reference to FIG. In FIG. 1, a fermentation tank 10 is connected with sampling pipes 1a and 1b (hereinafter referred to as pipes 1a and 1b) as bypass passages above and below the fermentation tank 10. The pipe 1a is provided with a gate valve 3 and the pipe 1b is provided with a pump. 2 is provided, and the measuring cell 5 is interposed and communicated between the pipes 1a and 1b. One end of the thermocouple 6 is arranged in the measuring cell 5, and the other end of the thermocouple 6 is connected to the calculator 8 by an electric wire. In addition, an ultrasonic transducer 4 is arranged in the measuring cell 5, and the ultrasonic transducer 4 is connected to an arithmetic unit 8 via an amplifier 7.
It is connected to the. In addition, the piping 1 centered around the measurement cell 5
The thermostat 9a including a and 1b is penetrated, and a cooling / heating device 9b is connected to the thermostat 9a by piping.

In the above structure, the bypasses of the pipes 1a and 1b are provided for the fermentation liquid sample, and the fermentation liquid in the fermentation tank 10 is supplied to the measuring cell 5 by the pump 2. The temperature of the fermented liquid supplied into the measuring cell 5 is measured by the thermocouple 6, and ultrasonic waves are transmitted from the vibrator 4 and reflected waves are received in the measuring cell 5. The transmission signal of the ultrasonic transducer 4 is sent from the calculator 6 through the amplifier 7, and the reception signal of the transducer 4 and the temperature signal of the thermocouple 6 are input to the calculator 6.

In such a measurement, the bubbles generated by the bacterial cells hinder the measurement and bring about a decrease in accuracy. However, by setting the temperature of the fermentation solution to a temperature range outside the temperature range in which the bacterial cells become active, Occurrence can be suppressed.
The constant temperature bath 9a is for that purpose, and cold water or hot water is supplied from the cooling / heating device 9b into the constant temperature bath 9a to set the temperature of the fermented liquid to a temperature range in which bubbles are not generated, thereby improving the measurement accuracy. . The temperature of the fermented liquid is set to the above-mentioned temperature range, and the temperature signal of the fermented liquid and the time intervals of transmission and reception by the ultrasonic oscillator 4 are performed several times while changing the temperature.
The calculator 8 calculates the speed of sound and then determines the ethanol concentration from the temperature characteristics and the speed of sound. The ethanol concentration n _E of the fermentation broth is expressed by the following equation (Equation 1).

[Equation 1]

The pump 2 serves to supply the fermented liquid from the fermentation tank 10 to the measuring cell 5, and the fermented liquid can be pressurized by driving the pump 2 with the sluice valve 3 closed. The generation of bubbles can also be suppressed by pressurizing the fermentation liquid by the pump 2. In this way, highly accurate and rapid measurement of ethanol concentration became possible continuously.

[0011]

As described above, according to the present invention, the generation of bubbles due to bacterial cells can be suppressed, and the temperature characteristic of the sonic velocity of the fermentation broth can be obtained. Therefore, the pretreatment of the fermentation broth becomes unnecessary. In addition, rapid and highly accurate ethanol concentration measurement can be performed at low cost without being affected by coexisting bacterial cells and sugars.

[Brief description of drawings]

FIG. 1 is a configuration diagram according to an embodiment of the present invention.

[Explanation of symbols]

 1a, 1b Piping 2 Pump 3 Gate valve 4 Transducer 5 Measuring cell 6 Thermocouple 7 Amplifier 8 Computing unit 9a Constant temperature bath 9b Cooling / heating device 10 Fermentation tank

Claims (1)

[Claims] 1. A measurement in which a pump and a sluice valve are provided in a sampling pipe whose both ends are connected to a fermentation tank, and an ultrasonic transducer is arranged inside the pump and the sluice valve and communicated with the sampling pipe. A cell, a thermocouple with one end inserted in the measuring cell, an ethanol concentration calculator connected to the other end of the thermocouple, and an amplifier connected between the calculator and the ultrasonic transducer. An ethanol concentration measuring device comprising: a thermostatic chamber in which the measuring cell is housed and through which the sampling pipe penetrates; and a cooling / heating device for supplying cold water or hot water into the thermostatic chamber.