JP5831062B2 - Wastewater recovery system - Google Patents

Description

  The present invention relates to a wastewater recovery system that recovers wastewater discharged from a sterilization apparatus.

  Packaged foods and beverages such as beverage cans and canned foods (hereinafter also referred to as “objects to be processed”) are sterilized in a sealed container such as a retort kettle or pastorizer after filling a liquid or food in a sealed container.

  2. Description of the Related Art Conventionally, a sterilization treatment apparatus has been proposed that sequentially executes a sterilization (heating) process in which an object to be treated is heated at a set temperature for a certain period of time with warm water and a cooling process for cooling the object to be treated to a certain temperature or less with cold water. Yes. In this sterilization apparatus, hot water that heats the object to be processed and cold water that cools the object to be processed are collected in a tank and reused (see, for example, Patent Document 1).

JP 2008-295411 A

  When a beverage can is sterilized by a sterilization apparatus, harmful substances such as formaldehyde may be detected from the collected water. Formaldehyde contained in the collected water is considered to have eluted from the paint or the like printed on the side of the beverage can. At present, it is technically difficult to remove formaldehyde from the recovered water. Therefore, when the recovered water contains formaldehyde, the water was not reused and was discharged to sewers and rivers after being diluted to below the standard value established by local governments using a large amount of water. .

  Accordingly, an object of the present invention is to provide a wastewater recovery system that can reuse more water while ensuring the safety of water used in sterilization treatment or the like.

The present invention has a storage unit that can store an object to be processed and introduces steam or hot water into the storage part to sequentially perform pre-heat treatment and sterilization of the object to be processed, and after the sterilization treatment, Is a wastewater collection system that is connected to a sterilization treatment device that cools the object to be treated and collects wastewater discharged from the sterilization treatment device to the sterilization treatment device, and is discharged from the sterilization treatment device. A drainage line through which the wastewater flows, a drainage temperature detection unit for detecting the temperature of the drainage flowing through the drainage line, an out-of-system discharge line for discharging the wastewater flowing through the drainage line out of the system, and the drainage line a recovery line for collecting the waste water flowing into the sterilization apparatus, a distribution destination switching means for the distribution destination of the drain switch to the outside of the system discharge line or the return line, the formaldehyde in the waste water Set reference temperature based on the time, the concentration of formaldehyde is increased as the temperature of the water is higher, based on the fact that decreases as temperature decreases, the detected temperature of the waste water detected by the water discharge temperature detector distribution destination but switches the distribution destination of the waste water if the reference temperature over the outside of the system discharge line, so that the detected temperature is switched to the recovery line is less than the reference temperature, for controlling the flow destination switching means And a switching control unit.

  The reference temperature is preferably a temperature at which the concentration is 0.05 mg / L or less.

  Moreover, it is preferable that reference temperature is 40 degrees C or less.

  In addition, the recovery line includes an accelerated oxidation treatment unit that performs accelerated oxidation treatment on wastewater, an activated carbon treatment unit that performs activated carbon treatment on wastewater that has undergone accelerated oxidation treatment, and ultrafiltration on wastewater that has undergone activated carbon treatment. It is preferable to provide a filtration processing unit that performs filtration using a membrane or a microfiltration membrane.

  ADVANTAGE OF THE INVENTION According to this invention, the waste_water | drain collection | recovery system which can reuse more water can be provided, ensuring the safety | security of the water used by a sterilization process etc.

It is a schematic structure figure showing sterilization processing system 1 of an embodiment. It is a graph which shows the result of having measured the relationship between the heating time (minute) of a to-be-processed object, and the density | concentration (mg / L) of formaldehyde for every heating temperature. It is a flowchart which shows the process sequence in case the control part 7 of embodiment performs control which switches the distribution destination of the waste_water | drain W1.

  Hereinafter, an embodiment of a wastewater recovery system according to the present invention will be described with reference to the drawings. In the present embodiment, a sterilization treatment system including a sterilization treatment device and a wastewater collection system will be described. FIG. 1 is a schematic configuration diagram showing a sterilization processing system 1 of the present embodiment.

  As shown in FIG. 1, the sterilization treatment system 1 of this embodiment includes a sterilization treatment device 2, a temperature sensor 3 as a waste water temperature detection unit, a first drain valve 4 and a second drain valve as distribution destination switching means. 5, a collection tank 6, and a control unit 7 as a distribution destination switching control unit.

  The sterilization treatment system 1 includes a circulating water tank 8, a pressure pump 9, a flow rate sensor 10, an accelerated oxidation treatment unit 11, an activated carbon treatment unit 12, a sterilizing agent addition device 13, and a filtration treatment unit 14. A turbidity measuring device 15, a residual chlorine concentration measuring device 16, and a pH value measuring device 17. In FIG. 1, a path of electrical connection between the temperature sensor 3, the first drain valve 4, the second drain valve 5, and the control unit 7 is indicated by a broken line. Illustration of other electrical connection paths is omitted.

  Furthermore, the sterilization processing system 1 includes a drainage line L1, an out-of-system discharge line L2, a recovery line L3, a drainage transfer line L4, and a blow line L5. The “line” in the present specification is a general term for lines capable of flowing a fluid such as a flow path, a path, and a pipeline.

  In the sterilization treatment system 1 shown in FIG. 1, the drain line L1, the outside drain line L2, the recovery line L3, the temperature sensor 3, the first drain valve 4, the second drain valve 5, and the control unit 7 are the same as those in the present embodiment. Configure drainage collection system.

  The sterilization apparatus 2 is a retort kettle having an accommodating portion 21 that can accommodate a beverage can (not shown) as an object to be processed. The sterilization processing apparatus 2 sequentially performs pre-heat treatment, sterilization processing, and cooling processing described later on the beverage cans stored in the storage unit 21.

  The pre-heat treatment is a process of introducing steam or hot water into the accommodating portion 21 and heating the beverage can to a set temperature (described later). When heating by introducing warm water, it is preferable to pressurize the inside of the sterilization apparatus 2 in order to prevent the contents filled in the beverage can from expanding. The same applies to the sterilization treatment described later.

  The sterilization process is a process in which steam or hot water is introduced into the housing portion 21 following the pre-heat treatment, and the beverage can is heated at a set temperature for a predetermined time. The set temperature in the above-described preheat treatment and sterilization treatment is, for example, 110 ° C to 120 ° C.

  The cooling process is a process of cooling the beverage can by introducing cold water into the accommodating portion 21. In the cooling process, the temperature of the cold water is lowered step by step, and finally the cold water at 20 ° C. is introduced to cool the beverage can to below 40 ° C. In addition, when cooling by introduce | transducing cold water, in order to prevent the expansion | swelling etc. of the content with which the drink can was filled, it is preferable to pressurize the inside of the sterilization processing apparatus 2. FIG.

  In each said process, the warm water and cold water used for heating and cooling are discharged | emitted as the waste_water | drain W1 to the exterior of the sterilization processing apparatus 2 via the waste_water | drain line L1.

  The downstream end of the recovery line L3 is connected to the primary side (water supply side) port of the sterilization apparatus 2. In addition, an upstream end portion of the drainage line L1 is connected to the secondary side (drainage side) port of the sterilization apparatus 2.

The temperature sensor 3 is a device that detects the temperature of the waste water W1 that flows through the drain line L1. The temperature sensor 3 is connected to the drain line L1 at the connection portion J1. The connection part J1 is arrange | positioned between the sterilization processing apparatus 2 and the branch part J2 (after-mentioned). The temperature sensor 3 is electrically connected to the control unit 7. The temperature of the waste water W1 detected by the temperature sensor 3 (hereinafter also referred to as “detected temperature value T _s ”) is transmitted to the control unit 7 as a detection signal.

  The drainage line L1 is a line through which the wastewater W1 discharged from the sterilization treatment device 2 is distributed toward the out-of-system discharge line L2 or the recovery line L3. The downstream side of the drainage line L1 branches off to the outside discharge line L2 and the recovery line L3 at the branch portion J2.

The out-of-system discharge line L2 is a line that discharges the waste water W1 that is discharged from the sterilization apparatus 2 and flows through the drain line L1 to the outside of the system. The downstream end of the out-of-system discharge line L2 is opened toward a wastewater treatment facility (not shown) attached to a beverage factory, a food factory, or the like. In the present embodiment, the waste water W1 having a reference temperature T _b (described later) or higher flows through the out-of-system discharge line L2.

The collection line L3 is a line that causes the sterilization treatment device 2 to collect the waste water W1 that is discharged from the sterilization treatment device 2 and flows through the drainage line L1. In the present embodiment, drainage water W1 having a temperature _lower than the reference temperature Tb flows through the recovery line L3.

  The upstream end of the recovery line L3 is connected to the drain line L1 at the branch portion J2. Further, the downstream end of the recovery line L3 is connected to the primary port of the sterilization apparatus 2. As shown in FIG. 1, the recovery line L3 connects a section connecting the branch portion J2 of the drainage line L1 and the recovery tank 6, and a connection between the circulating water tank 8 and the primary port of the sterilization apparatus 2. Is divided into sections. The collection tank 6 and the circulating water tank 8 are connected by a drainage transfer line L4. The drainage transfer line L4 is a line through which the wastewater W1 stored in the recovery tank 6 is circulated toward the circulating water tank 8.

  The first drain valve 4 is a device that opens and closes the extra-system discharge line L2. The first drain valve 4 is electrically connected to the control unit 7. The opening and closing of the valve body in the first drain valve 4 is controlled by a drive signal from the control unit 7.

  The second drain valve 5 is a device that opens and closes the recovery line L3. The second drain valve 5 is electrically connected to the control unit 7. The opening and closing of the valve body in the second drain valve 5 is controlled by a drive signal from the control unit 7.

  The 1st drain valve 4 and the 2nd drain valve 5 comprise the distribution destination switching means in this embodiment. By controlling the opening and closing of the first drain valve 4 and the second drain valve 5, the distribution destination of the waste water W1 discharged from the sterilization apparatus 2 can be switched to the outside discharge line L2 or the recovery line L3.

  That is, by setting the first drain valve 4 in the open state and the second drain valve 5 in the closed state, the waste water W1 discharged from the sterilization apparatus 2 can be circulated to the outside discharge line L2. Moreover, the waste_water | drain W1 discharged | emitted from the sterilization processing apparatus 2 can be distribute | circulated to the collection | recovery line L3 by making the 1st drain valve 4 into a closed state and making the 2nd drain valve 5 into an open state.

  The collection tank 6 is a facility for storing the waste water W1 that flows through the collection line L3. A drainage transfer line L4 is connected to the side surface near the bottom of the recovery tank 6. The waste water W1 stored in the collection tank 6 is supplied to the circulating water tank 8 through the waste water transfer line L4.

  A blow line L5 is connected to the side surface near the bottom of the recovery tank 6. The blow line L5 is a line for draining the waste water W1 stored in the recovery tank 6 to the outside of the system. The concentration of impurities contained in the waste water W1 stored in the recovery tank 6 increases with time. For this reason, the blow process which forcibly drains the waste water W1 out of the system is performed regularly (about once a month).

The control unit 7 includes a microprocessor (not shown) including a CPU and a memory. Control unit 7, based on the reference temperature T _b which is set for the detected temperature value T _s of the waste water W1 detected by the temperature sensor 3, drainage W1 distribution destination outside the system discharge line L2 or recovery line L3 of The opening and closing of the first drain valve 4 and the second drain valve 5 are controlled so as to be switched.

Specifically, the control unit 7 controls the first drain valve 4 to be in an open state and the second drain valve 5 to be in a closed state if the detected temperature value T _s ≧ reference temperature T _b . As a result, the distribution destination of the waste water W1 is switched to the outside discharge line L2. Further, if the detected temperature value T _s <reference temperature T _b , the control unit 7 controls the first drain valve 4 to the closed state and the second drain valve 5 to the open state. As a result, the distribution destination of the waste water W1 is switched to the recovery line L3. Control of the first drain valve 4 and the second drain valve 5 by the controller 7 will be described later.

In the present embodiment, the reference temperature _Tb is set based on the concentration of formaldehyde contained in the waste water W1. Here, the relationship between the reference temperature _Tb and the concentration of formaldehyde will be described. FIG. 2 is a graph showing the results of measuring the relationship between the heating time (minutes) of the object to be processed (beverage can) and the concentration of formaldehyde (mg / L) for each heating temperature.

  In FIG. 2, the horizontal axis indicates the heating time (minutes), and the vertical axis indicates the detected aldehyde concentration (mg / L). In this experiment, ion exchange water was put into a beaker having a capacity of 1 L, covered with aluminum foil, and then the water temperature was adjusted to a set temperature with a water bath. After the water temperature was stabilized, a commercial beverage can serving as a sample was put into a beaker. A pattern is printed on the side of the beverage can. The paint (ink) used for the printing contains formaldehyde.

  Moreover, in this experiment, the time after putting a drink can into a beaker was made into heating time, ion-exchange water was sampled from the beaker for every preset heating time, and the concentration of formaldehyde was measured. About 5 mL of water was used each time.

  The set temperatures were 40 ° C., 60 ° C., 80 ° C., and 100 ° C. Moreover, in order to make the conditions close to the actual sterilization treatment, the heating time was lengthened as the set temperature was low, and the heating time was shortened as the set temperature was increased.

  As shown in FIG. 2, it became clear that the concentration of formaldehyde increases as the set temperature increases and decreases as the set temperature decreases. When the set temperature was 40 ° C., the formaldehyde concentration was 0.05 mg / L even when the heating time of 420 minutes (7 hours) had elapsed. If the formaldehyde concentration is 0.05 mg / L or less, the concentration is not harmful to the human body.

Reference temperature _{T b} in the present embodiment, the temperature at which the concentration of formaldehyde becomes less 0.05 mg / L. Specifically, in this embodiment, the reference temperature _Tb is set to 40 ° C.

Returning to FIG. 1 again, the configuration of the sterilization processing system 1 will be described.
The circulating water tank 8 is a facility for storing the drainage water W1 supplied from the recovery tank 6 as circulating water W2. The waste water W1 stored in the circulating water tank 8 flows through the recovery line L3 as the circulating water W2 from the circulating water tank 8 toward the sterilization apparatus 2. The circulating water tank 8 is connected to a makeup water line (not shown). The makeup water line is a line for supplying makeup water to the circulation water tank 8 when the water level of the circulation water tank 8 is low.

  The pressurizing pump 9 is a device that sucks the circulating water W2 and discharges the circulating water W2 toward the primary port of the sterilization treatment device 2. The pressurizing pump 9 is provided in the recovery line L3 between the circulating water tank 8 and the accelerated oxidation processing unit 11.

  The flow rate sensor 10 is a device that detects the flow rate of the circulating water W2 flowing through the recovery line L3. The flow sensor 10 is connected to the recovery line L3 at the connection portion J3 on the downstream side of the pressurizing pump 9. The flow sensor 10 is electrically connected to the control unit 7. The flow rate of the circulating water W2 detected by the flow sensor 10 is transmitted to the control unit 7 as a detection signal.

  The accelerated oxidation treatment unit 11 is a facility that performs accelerated oxidation treatment on the circulating water W2. “Accelerated oxidation treatment” means that a specific oxidizing agent is irradiated with ultraviolet rays to generate hydroxyl radicals having a strong oxidizing power inside the circulating water W2, thereby causing the hardly decomposable content contained in the circulating water W2. This refers to a treatment that combines oxidative decomposition of harmful substances, decomposition of chromaticity components and odor components of circulating water W2, sterilization of microorganisms, and the like. The accelerated oxidation processing unit 11 is provided on the downstream side of the pressurizing pump 9 (J3). The accelerated oxidation processing unit 11 includes an oxidant addition device 11a and an ultraviolet irradiation device 11b.

  The oxidant addition device 11a is a device that adds an oxidant to the circulating water W2. The oxidizing agent is used as a sterilizing agent that suppresses the growth of bacteria in the circulating water W2, and is also used as an oxidizing agent when performing the accelerated oxidation treatment in the ultraviolet irradiation device 11b. Examples of the oxidizing agent include sodium hypochlorite and hydrogen peroxide.

  The ultraviolet irradiation device 11b is a device that irradiates the circulating water W2 to which the oxidizing agent is added by the oxidizing agent adding device 11a with ultraviolet rays. The ultraviolet irradiation device 11b includes an ultraviolet lamp (not shown) that irradiates the circulating water W2 with ultraviolet rays, and a treatment tank (not shown) through which the circulating water W2 flows.

  The ultraviolet lamp is configured to be able to irradiate the circulating water W2 with ultraviolet rays having a preset wavelength. The treatment tank has a shape (for example, a cylindrical shape) through which the circulating water W2 can flow. The ultraviolet lamp is accommodated in the processing tank. The circulating water W2 flowing through the treatment tank contains the oxidizing agent added by the oxidizing agent adding device 11a. When this oxidizing agent is irradiated with ultraviolet rays from an ultraviolet lamp, hydroxyl radicals are generated inside the circulating water W2. Thereby, the hardly decomposable harmful substance contained in the circulating water W2 is oxidatively decomposed. Further, the chromaticity component and odor component of the circulating water W2 are decomposed. Furthermore, microorganisms contained in the circulating water W2 are sterilized.

  The activated carbon treatment unit 12 is a device that performs activated carbon treatment on the circulating water W <b> 2 that has been subjected to accelerated oxidation treatment by the accelerated oxidation treatment unit 11. “Activated carbon treatment” refers to a treatment of removing residual organic substances and the like contained in the circulating water W2 with activated carbon. The activated carbon treatment unit 12 is provided on the downstream side of the accelerated oxidation treatment unit 11.

  The sterilizing agent adding device 13 is a device that adds a sterilizing agent to the circulating water W2. By adding a disinfectant to the circulating water W2, it is possible to suppress the growth of microorganisms on the membrane surface in the subsequent filtration unit 14. Examples of the disinfectant include sodium hypochlorite.

  The filtration processing unit 14 is a device that performs filtration using an ultrafiltration membrane or a microfiltration membrane on the circulating water W2 that has been activated carbon-treated by the activated carbon treatment unit 12. The filtration processing unit 14 includes an ultrafiltration membrane module or a microfiltration membrane module (not shown). Impurities such as suspended substances contained in the circulating water W2 are removed by these filtration membrane modules. A prefilter (not shown) is provided on the upstream side of the filtration processing unit 14.

  The turbidity measuring device 15 is a device that is provided on the downstream side of the filtration processing unit 14 and measures the turbidity of the circulating water W2. The turbidity measuring device 15 is electrically connected to the control unit 7. The turbidity of the circulating water W2 measured by the turbidity measuring device 15 is transmitted to the control unit 7 as a detection signal.

  The residual chlorine concentration measuring device 16 is a device that is provided on the downstream side of the filtration processing unit 14 and measures the residual chlorine concentration of the circulating water W2. The residual chlorine concentration measuring device 16 is electrically connected to the control unit 7. The residual chlorine concentration of the circulating water W2 measured by the residual chlorine concentration measuring device 16 is transmitted to the control unit 7 as a detection signal.

  The pH value measuring device 17 is a device that is provided on the downstream side of the filtration processing unit 14 and measures the pH value of the circulating water W2. The pH value measuring device 17 is electrically connected to the control unit 7. The pH value of the circulating water W2 measured by the pH value measuring device 17 is transmitted to the control unit 7 as a detection signal.

  The control unit 7 receives detection signals from the turbidity measuring device 15, the residual chlorine concentration measuring device 16, and the pH value measuring device 17, and when the turbidity of the circulating water W2 exceeds the reference value, the residual chlorine concentration of the circulating water W2 Exceeds the reference value, or when the pH value of the circulating water W2 exceeds the reference value, for example, an alarm (not shown) is controlled to notify the system administrator of the occurrence of an abnormality.

  In FIG. 1, the circulating water W2 sent from the circulating water tank 8 to the recovery line L3 is processed by the accelerated oxidation processing unit 11, the activated carbon processing unit 12, the bactericide adding device 13, and the filtration processing unit 14, respectively. It is supplied to the primary side port of the sterilization treatment apparatus 2. And in the sterilization processing apparatus 2, it is used for pre-heat processing, sterilization processing, and cooling processing as warm water or cold water. When the amount of circulating water W2 supplied to the sterilization treatment device 2 is small, makeup water is supplied in the recovery line L3 upstream from the primary port of the sterilization treatment device 2.

  Next, in the sterilization processing system 1 configured as described above, control in which the control unit 7 switches the distribution destination of the waste water W1 will be described. FIG. 3 is a flowchart showing a processing procedure when the control unit 7 executes control for switching the distribution destination of the waste water W1. The processing of the flowchart shown in FIG. 3 is repeatedly executed during operation of the sterilization processing system 1.

In step ST101 shown in FIG. 3, the control unit 7 obtains the detected temperature value _{T s} of the waste water W1 from the temperature sensor 3.

In step ST 102, the control unit 7, the detected temperature value _{T s} is equal to or reference temperature _{T b} or more. In step ST102, when the control unit 7 determines that the detected temperature value T _s ≧ the reference temperature T _b (YES), the process proceeds to step ST103. In step ST102, when the control unit 7 determines that the detected temperature value T _s <reference temperature T _b (NO), the process proceeds to step ST104.

  In step ST103 (step ST102: YES), the control unit 7 transmits a drive signal to the first drain valve 4 to control the first drain valve 4 to an open state. Moreover, the control part 7 transmits a drive signal to the 2nd drain valve 5, and controls the 2nd drain valve 5 to a closed state. Thereafter, the processing of this flowchart ends.

  When the control unit 7 executes the process of step ST103, the distribution destination of the waste water W1 discharged from the sterilization apparatus 2 is switched from the drain line L1 to the outside discharge line L2. As a result, the waste water W1 flows through the outside discharge line L2 and is discharged to a sewer (not shown).

  On the other hand, in step ST104 (step ST102: NO), the controller 7 transmits a drive signal to the first drain valve 4 to control the first drain valve 4 to be closed. Moreover, the control part 7 transmits a drive signal to the 2nd drain valve 5, and controls the 2nd drain valve 5 to an open state. Thereafter, the processing of this flowchart ends.

  When the control unit 7 executes the process of step ST104, the distribution destination of the wastewater W1 discharged from the sterilization apparatus 2 is switched from the drainage line L1 to the recovery line L3. As a result, the waste water W1 flows through the recovery line L3 and is recovered in the recovery tank 6.

  According to the sterilization processing system 1 of the present embodiment described above, for example, the following effects can be obtained.

Sterilization system 1 of the present embodiment, on the basis of the reference temperature T _b which is set for the detected temperature value T _s of the waste water W1 discharged from the sterilization apparatus 3, the outside of the system discharge line distribution destination wastewater W1 The control part 7 which switches to L2 or the collection line L3 is provided. If the detected temperature value T _s ≧ reference temperature T _b , the control unit 7 switches the distribution destination of the waste water W1 from the drain line L1 to the outside discharge line L2. If the detected temperature value T _s <reference temperature T _b , the control unit 7 switches the distribution destination of the waste water W1 from the drain line L1 to the recovery line L3.

According to this, if detected temperature value T _s ≧ reference temperature T _b , the degree to which formaldehyde is eluted in the waste water W1 is high, and the concentration of formaldehyde increases, so the waste water W1 is discharged outside the system without being recovered. Is done. If the detected temperature value T _s <the reference temperature T _b , the degree to which formaldehyde is eluted in the waste water W1 is low and the concentration of formaldehyde is low, so that the waste water W1 is collected in the sterilization apparatus 2. In this case, the waste water W1 can be reused for heating and cooling. Therefore, according to the sterilization treatment system 1 of the present embodiment, more water can be reused while ensuring the safety of water used in the sterilization treatment or the like.

In the sterilization treatment system 1 of the present embodiment, the reference temperature _Tb is set based on the concentration of formaldehyde in the waste water W1. For this reason, the concentration of formaldehyde in the circulating water W2 can be suppressed, and more water can be reused while the water treatment facility on the recovery line L3 has a simple configuration.

Further, in the sterilizing treatment system 1 of the present embodiment, the reference temperature T _b is set to a temperature at which the concentration of formaldehyde becomes less 0.05 mg / L. For this reason, the concentration of formaldehyde in the circulating water W2 can be suppressed, and more water with high safety can be reused while the water treatment facility on the recovery line L3 has a simple configuration.

Moreover, in the sterilization processing system 1 of the present embodiment, the reference temperature _Tb is 40 ° C. or less. For this reason, the concentration of formaldehyde in the circulating water W2 can be more reliably suppressed.

  Moreover, the sterilization processing system 1 of this embodiment includes an accelerated oxidation processing unit 11, an activated carbon processing unit 12, and a filtration processing unit 14. For this reason, the water quality of the circulating water W2 to be reused can be further improved.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and can be implemented in various forms.

  For example, in this embodiment, the example which used the sterilization processing apparatus 2 as the retort pot was demonstrated. Not limited to this example, the sterilization apparatus 2 may be a pasteurizer, or may be a sterilization apparatus having a function equivalent to that of a retort pot or a pasterizer.

  Moreover, in this embodiment, the drink can was demonstrated as an example to be processed. The material to be processed is not limited to this example, and can be canned or packed food (food that is vacuum-packed).

DESCRIPTION OF SYMBOLS 1 Sterilization processing system 2 Sterilization processing apparatus 3 Temperature sensor (drainage temperature detection part)
4 First drain valve (distribution destination switching means)
5 Second drain valve (distribution destination switching means)
7 Control unit (distribution switching control unit)
11 Accelerated oxidation treatment unit 12 Activated carbon treatment unit 14 Filtration treatment unit 21 Storage unit L1 Drainage line L2 Drainage line L3 Recovery line W1 Drainage W2 Circulating water

Claims (4)

It has a storage part that can store the object to be processed, and introduces steam or hot water into the storage part, sequentially performs pre-heat treatment and sterilization treatment of the object to be processed, and introduces cold water into the storage part after the sterilization process. A wastewater recovery system connected to a sterilization treatment device that performs cooling treatment of an object to be processed, and recovers wastewater discharged from the sterilization treatment device to the sterilization treatment device,
A drainage line through which the drainage discharged from the sterilization apparatus flows,
A waste water temperature detector for detecting the temperature of the waste water flowing through the drain line;
An outside discharge line for discharging waste water flowing through the drain line to the outside of the system;
A collection line for collecting the waste water flowing through the drain line to the sterilization apparatus;
Distribution destination switching means for switching the distribution destination of wastewater to the outside discharge line or the recovery line;
A reference temperature is set based on the concentration of formaldehyde in the waste water, and the concentration of formaldehyde is detected by the waste water temperature detection unit based on the fact that the concentration of formaldehyde increases as the temperature of water increases and decreases as the temperature decreases. that if the detected temperature of the waste water is the reference temperature or more switches the distribution destination of the waste water to the outside of the system discharge line, so that the detected temperature is switched to the recovery line is less than the reference temperature, the flow destination switching means Distribution destination switching control unit for controlling
Effluent recovery system with The waste water recovery system according to claim 1 , wherein the reference temperature is a temperature at which the concentration is 0.05 mg / L or less. Waste water recovery system according to claim 1 or 2 reference temperature is 40 ° C. or less. The recovery line includes an accelerated oxidation treatment unit that performs accelerated oxidation treatment on the wastewater, an activated carbon treatment unit that performs activated carbon treatment on the wastewater that has undergone accelerated oxidation treatment, and an ultrafiltration membrane or wastewater that has undergone activated carbon treatment. The wastewater recovery system according to any one of claims 1 to 3 , further comprising a filtration processing unit that performs filtration using a microfiltration membrane.

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