JPH0464658B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a cold brine treatment apparatus for cooling and preserving foods such as meat and fresh fish by immersing them in cool brine.

(b) Conventional technology For example, Japanese Utility Model Publication No. 56-12936 discloses a system equipped with a water tank for storing frozen food, a cooler, and an ozone generator.
Introduce the pipe connected to the outlet of the filtration tank inside the water tank to the inlet side of the cooler through the water suction pump, place the tip of the pipe connected to the outlet of the cooler inside the water tank, and apply ozone to the bottom of the tank. A device for defrosting frozen foods is shown which is provided with a bubble generator for generating bubbles.

(c) Problems to be solved by the invention In the above frozen food thawing apparatus, when frozen food such as fish or meat fillets is immersed in a water tank, the osmotic pressure of the water increases as the ice melts. As a result, oxidation phenomena occur due to the outflow of meat juices into the water or the ingress of water, resulting in deterioration of quality, so it is necessary to put the food into a plastic bag or the like and put it into the water tank, making the thawing process complicated. . In addition, when salt is dissolved in the water in the aquarium to adjust the osmotic pressure in order to solve the above problem, rust tends to form on the water suction pump, piping, aquarium, etc. made of metal materials, and corrosion due to rust occurs. In this case, a problem arises in that the life of the product is shortened.

(d) Means for Solving the Problems In order to solve the above problems, the present invention provides a water storage tank for storing salt water, a pump for circulating the salt water, and a cooling pipe for cooling the salt water in the water storage tank. an electrode provided apart from the cooling pipe and submerged in the salt water; a positive terminal on the output side for applying a positive voltage to the electrode; and a negative terminal on the input side for applying a negative voltage to the cooling pipe. a constant current generating circuit that flows a constant current from the electrode to the cooling pipe through the salt water; and a water shortage detection signal that compares the voltage of the positive terminal and the voltage of the negative terminal to stop operation of the pump. The present invention provides a cold salt water treatment device characterized by comprising a comparator for outputting the cold salt water.

(E) Function When filling an aquarium with salt water of a predetermined concentration and storing meat and fish foods in this aquarium for cooling preservation, each food has a different osmotic pressure, so the osmotic pressure must be adjusted to suit the various foods. For this reason, it is necessary to adjust the concentration of the brine to change each time you change the soaked food.
The conductivity of salt water varies. However, a constant current flows from the electrode connected to the positive terminal of the constant current circuit to the cooling pipe connected to the negative terminal of the constant current circuit via the salt water, regardless of the change in the current conductivity. Additionally, if the salt water in the water storage tank is drained and the electrode is exposed to air, the difference between the voltage at the positive terminal and the voltage at the negative terminal becomes zero, and the comparator outputs a water shortage detection signal, causing the pump to Operation will be stopped.

(F) Embodiment Hereinafter, an embodiment of the present invention will be described in detail based on the drawings. FIG. 2 shows a side view of the cold salt water treatment apparatus 1, and FIG. 3 shows a plan view thereof. Reference numeral 2 denotes a water storage tank defined by an insulated box that opens upward, and inside there are a main water tank 4 and a sub-water tank 5 on the left and right sides separated by a partition plate 3.
are divided into sections. A net shelf 6 is installed at the bottom of the main water tank 4 to store food. Sub-tank 5
Inside, a screen 7 as a filter is installed horizontally below the upper end of the partition plate 3, and further below the screen 7, a cooling pipe 8 included in the refrigeration cycle of the cooling device 9 is spaced apart from the bottom of the water storage tank 2. will be placed. Further, a draining table 10 is installed at the opening of the water tank 2 above the sub-water tank 5. 12 is an electric compressor 13 and a condenser 14 that constitute the refrigeration cycle of the cooling device;
It is a unit box that houses a sterilizer 15 consisting of an ozone generator, and is arranged on the side of the water tank 2 on the side of the sub-water tank 5, from which the cooling pipe 8 extends into the sub-water tank 5. The upper surface of the box body 12 is a flat surface, and its height is the same as that of the draining stand 10. This allows the top surface of the box 12 to be used as a table. Further, since the draining table 10 is located on the sub-water tank 5, it is very easy to drain the food 17 after cooling, washing, or thawing.

When the food to be stored is meat or fresh fish, the salt water 18 injected into the water storage tank 2 is mixed with salt to adjust the osmotic pressure, and the salt water is about 1% for meat and 3.5% for fresh fish. It is said that Salt water 18 is box body 1
The pump 19, which will be described later, is installed in the tank 2, and the suction pipe 20 opens at the bottom of the sub-tank 5. After being sterilized by the sterilizer 15, the water is sucked into the main tank 4 through the discharge pipe 21 opened at the bottom of the main tank 4. is discharged. The water level in the main water tank 4 is set to exceed the height of the partition plate 3 in advance, so that the overflowing salt water 18 is filtered by the screen 7 and falls into the sub water tank 5 to be stored there, and is then returned to the suction pipe 20. It goes through a cycle of being sucked in. At this time, the water level in the sub-tank 5 is set above the cooling pipe 20, thereby cooling the water to, for example, +5°C for vegetables, 0°C for meat, and -2°C for fresh fish. Such foods are cooled by cold water in the main water tank 4, which has the effect of increasing the cooling rate of their core temperatures. Further, even when used for washing food, since the screen 7 filters out dirt, the pump 19 etc. will not be clogged.

Since the salt water 18 contains food odors and fine particles that have not been filtered through the screen 7, it needs to be replaced. Therefore, in the present invention, as shown in FIG.
A conduit 51 that is suspended and branched is provided, and a normally closed valve 53 is installed in the middle of this conduit 52. That is, salt water 1
8, remove the partition plate 3 and open the valve 53 to communicate the main water tank 4 and the sub-water tank 5.
2 flows down and is discharged from the discharge port 54.
Also, since the discharge pipe 21 is positioned above the conduits 51, 52, etc. at this time, the water 1 in the discharge pipe 21 is
8 also flows back through the pump 19 and the conduit 51 to the discharge port 5.
4, the wastewater inside each pipe can also be drained well.

The cooling pipe 8 is made of copper or nickel alloy, and lead wires 30 are connected to appropriate positions thereof as shown in FIG. Reference numeral 31 denotes an electrode made of, for example, titanium, which has better corrosion resistance than the copper or nickel alloy, and is spaced apart from the cooling pipe 8 and arranged so that its lower end is approximately at the same height as the lower part of the cooling pipe 8. ing.

Further, 40 in FIG. 1 is a constant current circuit, and this constant current circuit includes a series circuit of a first resistor R ₁ and a second resistor R ₂ connected in series between the DC power supply lines 41 and 42;
An amplifier 43 whose midpoint of this series circuit is connected to the positive input terminal, a third resistor R ₃ that determines the input voltage of the negative input terminal of this amplifier 43, and a fourth resistor R ₄ connected to the output terminal of the amplifier 43. The NPN type transistor 44 is connected through the NPN type transistor 44. Here, the emitter of the transistor 44 becomes an anode through a positive terminal 45 and is connected to the electrode 31 to which a positive voltage is applied, and the negative input terminal of the amplifier 43 is connected to the cooling pipe 8 which becomes a cathode through a negative terminal 46. It is continued. Also, 47
is a comparator, and R ₅ , R ₆ and R ₇ are the fifth, sixth and seventh resistors, respectively. Note that the negative input terminal of the comparator 47 is connected to the negative input terminal of the amplifier 43.

When DC power is applied between the DC power lines 41 and 42, it is transmitted from the positive terminal 45 of the constant current circuit 40 to the negative terminal 46 via the electrode 31, the salt water 18 which becomes a conductor, and the cooling pipe 8 which is the object to be protected against corrosion. For example, a weak direct current of 30 mA, which is necessary for this purpose, flows. As a result, the potential difference (energy difference) between the electrode 31 serving as the anode portion and the cooling pipe 8 serving as the cathode portion is eliminated, and cathodic protection is performed in which a dissolution reaction of the cooling pipe 8 is avoided. That is, corrosion of the cooling pipe 8 can be prevented by a cathodic protection method in which a weak direct current is caused to flow into the surface of the cooling pipe 8, which becomes the cathode portion, thereby extinguishing the corroded battery. here,
Corrosion batteries cause localized corrosion on metal surfaces.

Further, in the constant current circuit 40, a power supply voltage V _C is applied between the DC power supply lines 41 and 42, the reference potential of the positive input terminal of the amplifier 43 is set to V _P , and a corrosion protection voltage from the positive input terminal 45 of the constant current circuit 40 is applied. The output current is I _{0 and} the resistance values of the first, second and third resistors R ₁ , R ₂ and R ₃ are equal to the sign R ₁ , R ₂ and R ₃ respectively.
Then, it is expressed as V _P =V _C /(R ₁ /R ₂ +1) I ₀ ≈V _P /R ₃ and is biased from the output terminal of the amplifier 43 to the transistor 44 through the fourth resistor R ₄ . Due to this bias, the anticorrosion output current I ₀ flows from the positive terminal 45, and the amplifier 43 outputs an output so that the potential of the negative input terminal becomes equal to the potential of the positive input terminal, thereby changing the bias voltage.

The anti-corrosion output current _I0 of the constant current circuit 40 depends on the surface area and material of the portion of the cooling pipe 8 submerged in salt water, the length of the electrode 31, and the length of the cooling pipe 8 and the electrode 31.
This is determined by the distance from the When the surface area of the cooling pipe 8 is approximately 4.5 m ² , the material is an alloy of copper and nickel, the length of the electrode 31 is approximately 20 cm, and the distance between the cooling pipe 8 and the electrode 31 is approximately 20 cm, the anticorrosion output current is By setting I ₀ to 30mA,
Corrosion prevention of the cooling pipe 8 can be achieved.

Here, water is supplied into the water storage tank 2 to store meat, for example, and the concentration of the salt water 18 is reduced to about 1
%, the conductivity of the salt water 18 decreases due to its low concentration. When the conductivity decreases, it becomes difficult for the current to flow from the electrode 31 to the cooling pipe 8, and the current flowing through the third resistor _R3 , that is, the output current _I0 of the constant current circuit 40 decreases, and the third resistor R3 decreases. ₃ terminal voltage decreases. When the terminal voltage of the third resistor R ₃ decreases, the negative input voltage of the amplifier 43 also decreases, and the output voltage of the amplifier 43 increases. Therefore, the bias of the transistor 44 increases, the output current I ₀ of the constant current circuit 40 increases by the amount of the decrease, and the current flowing from the electrode 31 to the cooling pipe 8 becomes approximately equal to that before the conductivity changed.

Furthermore, when, for example, fresh fish is stored in the water storage tank 2, salt is supplied into the tank to increase the concentration of the salt water 18 to approximately 3.5%, the conductivity of the salt water 18 increases due to the increased concentration. do. When the conductivity increases, current flows more easily from the electrode 31 to the cooling pipe 8. Therefore, the third resistor
The current flowing through R ₃ , that is, the output current I ₀ increases, and the third
The terminal voltage of resistor R ₃ increases. When the terminal voltage of the third resistor R ₃ increases, the negative input voltage of the amplifier 43 also increases, and the output voltage of the amplifier 43 decreases. Therefore, the bias of the transistor 44 becomes smaller, the output current I ₀ of the constant current circuit 40 decreases by the increased amount, and the current flowing from the electrode 31 to the cooling pipe 8 becomes approximately equal to that before the conductivity changed.

Furthermore, when the electrode 31 and the cooling pipe 8 are submerged in the salt water 18 in the water storage tank 2, the comparator 47
The negative input voltage of is equal to the terminal voltage of the third resistor _R3 , which is always higher than the positive input voltage, so
The comparator 47 outputs a low level signal and does not output a drought detection signal. At this time, if the salt water 18 in the water storage tank 2 gradually escapes and the electrode 31 leaves the water surface due to a failure of the valve 53, for example, the gap between the electrode 31 and the cooling pipe 8, that is, the positive terminal 45 and the negative terminal 46 The gap between them becomes open. Therefore, the negative input voltage of the comparator 47 becomes zero V, the comparator 47 outputs a high level signal which is a drought detection signal, and a drought warning device (not shown) such as a buzzer operates. Further, the operation of the pump 19 is stopped by the water shortage detection signal.

Therefore, when the cooling pipe 8 and the electrode 31 provided apart from the cooling pipe are both submerged in the salt water 18 in the water storage tank 2, the salt water 1
8 as a conductor, a weak direct current flows from the electrode 31 toward the cooling pipe 8, and as a result, the potential difference (energy difference) between the electrode 31, which becomes the anode part, and the cooling pipe 8, which becomes the cathode part, disappears, and cooling is performed. pipe 8
Electrolytic protection can be achieved while avoiding the dissolution reaction. That is,
By connecting the cooling pipe 8 itself to the negative terminal 46 of the constant current circuit 40 and making it double as a cathode, a weak direct current flows into the surface of the cooling pipe 8 through the salt water 18 that serves as a conductor and electrolyte, thereby preventing corrosion. Corrosion of the cooling pipe 8 can be prevented by employing an electrochemical corrosion protection method that eliminates the battery.

In addition, since the electrode 31 is made of a metal material that has better corrosion resistance than the cooling pipe 8, the corrosion rate of the electrode 31 is slow, and the salt water 1 in the water storage tank 2
When the conductivity of the salt water 18 increases by increasing the concentration of the salt water 8, the constant current circuit 40 acts so that the output current _I0 does not increase, and the same current as before the concentration change flows from the electrode 31 for cooling. Because it flows into the pipe 8, the electrolysis of metal ions in the electrode 31 is approximately constant, and corrosion does not proceed rapidly. As a result, the electrode 31 can be used for a long period of time, and the output current
It is possible to keep I ₀ constant and reduce power consumption.

Furthermore, when the conductivity of the salt water 18 decreases by diluting the concentration of the salt water 18, the constant current circuit 40 acts to prevent the output current _I0 from decreasing, which is necessary for corrosion protection equal to that before the concentration change. Since a current flows from the electrode 31 to the cooling pipe 8, even if the concentration decreases, the corrosion battery can be extinguished and corrosion of the cooling pipe 8 can be reliably prevented.

Note that the constant current circuit according to the present invention is not limited to the constant current circuit 40 described in the above embodiment, and operates in response to changes in the conductivity of the salt water 18 to connect the electrode 31 and the cooling pipe 8. It is sufficient if the circuit always flows a constant current between the two.

(G) Effects of the Invention Since the present invention is the cold salt water treatment apparatus explained in the above embodiment, the cooling pipe for cooling the salt water stored in the water storage tank is connected to the negative terminal of the constant current circuit, and the cooling pipe is connected to the negative terminal of the constant current circuit. By connecting an electrode separated from the pipe and submerged in the salt water to the positive terminal of the constant current circuit, the cooling pipe itself can be used as a cathode, so that the output from the constant current circuit Of course, it is possible to prevent corrosion of the cooling pipe by flowing direct current from the electrode to the cooling pipe through the salt water, which serves as a conductor. Even if the concentration changes and therefore the conductivity of the salt water changes, a constant current is always output from the constant current circuit, and a constant current always flows from the electrode to the cooling pipe, so that the metal ions of the electrode The rate of electrolysis of is extremely slow, and even if salt is added, corrosion will not proceed rapidly.As a result, the electrode can be used for a long period of time, and the current flowing from the electrode to the cooling pipe can be kept constant. In addition, when the conductivity is low due to the low concentration of salt water, the constant current circuit acts to prevent the output current from decreasing, so that the same current is maintained regardless of changes in concentration. Since it flows from the electrode to the cooling pipe, even if the concentration decreases, corrosion batteries can be extinguished and corrosion of the cooling pipe can be reliably prevented. Additionally, if the salt water in the water storage tank is drained and the electrode is exposed to air, the difference between the voltage at the positive terminal and the voltage at the negative terminal becomes zero, and the comparator outputs a water shortage detection signal, causing the pump to Since operation is stopped, the pump can be protected in the event that salt water leaks from the water tank due to a malfunction of the drain valve or damage to the water pipe.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention,
FIG. 1 is a schematic electric circuit and a partial vertical sectional view of the cold salt water treatment device, FIG. 2 is a side view of the cold salt water treatment device, FIG. 3 is a plan view thereof, and FIG. 4 is a sectional view of a water storage tank. 2...Water tank, 8...Cooling pipe, 18...Salt water, 3
1... Electrode, 40... Constant current circuit, 45... Plus terminal, 46... Minus terminal.

Claims (1)

[Claims] 1. A water storage tank for storing salt water, a pump for circulating the salt water, a cooling pipe for cooling the salt water in the water storage tank, an electrode provided apart from the cooling pipe and submerged in the salt water, A constant current generating circuit that includes a positive terminal on the output side for applying a positive voltage to the electrode and a negative terminal on the input side for applying a negative voltage to the cooling pipe, and that flows a constant current from the electrode to the cooling pipe via the salt water. and a comparator that compares the voltage at the positive terminal and the voltage at the negative terminal and outputs a water shortage detection signal for stopping operation of the pump.