JP2012170878A - Wastewater sterilization system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wastewater sterilization system that can reduce heating energy and the amount of water used and moreover prevent a leakage of a pollution source contained in air when carrying out evacuation.SOLUTION: Wastewater Wd in a drain tank 10 is evacuated and led into a sealed tank 13, and then the wastewater in the sealed tank 13 is maintained to high temperature and high pressure and sterilized. A water seal type vacuum pump 20 is connected to the sealed tank 13, and a storage tank 15 is connected to the sealed tank 13 through a drain line 14. A wastewater heating heat exchanger 24 exchanging heat between treated water Wt after sterilization treatment and the wastewater Wd in the drain tank 10 is connected to the drain line 14, and a treated water circulation line 21 supplying and circulating the treated water Wt in the storage tank 15 to the water seal type vacuum pump 20 is connected to the storage tank 15.

Description

  The present invention relates to a wastewater sterilization system for sterilizing wastewater discharged from a biohazard facility or the like at high temperature and pressure.

  Biohazard facilities such as genetically modified plant factories, medical facilities, experimental research facilities that handle animals, etc., wastewater discharged from food and medical facilities, various types of genetically modified plant fragments, genetically modified cells, pathogenic bacteria, animal and plant cells, etc. Contained in an active state. In order to prevent the discharge of the wastewater containing these active contamination sources to the outside, it is necessary to sterilize the various pollution sources and drain them to the outside.

  In this wastewater sterilization process, as shown in Patent Document 1, wastewater such as a culture solution is captured and drained by capturing plant fragments and cells through a filter, and then high-temperature and high-pressure steam is applied to the filter capturing the plant fragments and cells. Has been proposed to inactivate plant pieces and cells to sterilize them. However, in order to capture plant pieces and cells with a filter, there is a problem of the filter size, and when high-temperature and high-pressure steam is supplied to the filter, there is a problem that a large amount of steam is generated as drainage after sterilization.

  Patent Document 2 introduces wastewater into a sealed tank, maintains the inside of the sealed tank at high temperature and high pressure, and directly sterilizes the wastewater. In order to treat each pollution source contained in various contaminated wastewater, It is possible to provide a safe sterilization system.

  This sterilization system will be described with reference to FIG.

  The sterilization system of FIG. 2 includes a drain tank 40 that stores wastewater such as a culture solution from a plant factory and the like, a sealed tank 41 that vacuums the drainage in the drain tank 40 and sterilizes it at high temperature and high pressure, A water-sealed vacuum pump 42 that evacuates the sealed tank 41 is mainly configured.

  Here, the drainage tank 40 is provided in the plant factory in the hazard management area, and the sealed tank 41 and the water-sealed vacuum pump 42 are separated from the plant factory, and are also provided in the machine room in the hazard management area. ing.

  In this sterilization system, the open / close valve 44 of the suction line 43 that sucks the waste water in the drain tank 40 into the sealed tank 41 is closed and the open / close valve 46 of the drain line 45 of the sealed tank 41 is closed, and the water-sealed vacuum pump 42. To evacuate the sealed tank 41. During this evacuation, water such as tap water is supplied from the water supply line 47 to the water ring vacuum pump 42, the vacuum seal of the water ring vacuum pump 42, lubrication of the rotating part, cooling of the sliding part, The air in the sealed tank 41 is sucked and discharged from the water supply line 47 on the downstream side of the water-sealed vacuum pump 42 to the drainage line 45 together with the water supply.

  After the sealed tank 41 is evacuated, the on-off valve 44 is opened, whereby the waste water in the drain tank 40 is sucked into the sealed tank 41, and then the on-off valve 44 is closed, and the heater 48 discharges the waste water in the sealed tank 41 to 121. By heating to ℃ (about 0.2 MPa) to a high temperature and high pressure state and keeping this for about 20 minutes, the contamination source in the waste water is sterilized. After the sterilization treatment, the drainage in the sealed tank 41 is discharged by opening the on-off valve 46 of the drainage line 45. At this time, since the waste water is at a high temperature, cold water (tap water) is supplied from the cold water line 49 branched from the water supply line 47 to the drain line 45, and the temperature of the waste water is allowed to flow to the general drainage system or less (for example, Drain at a temperature below 60 ° C.

  Waste water in the sealed tank 41 after sterilization is discharged at its own pressure, but since the inside of the sealed tank 41 becomes negative pressure with the discharge, the air introduction valve 50 is opened to introduce air into the sealed tank 41. To discharge. After draining the drained water after sterilization, the water-sealed vacuum pump 42 is evacuated again to perform sterilization as described above.

  In this wastewater sterilization system, since the wastewater is directly heated to a high temperature and high pressure, it is possible to sterilize a contamination source that cannot be removed by a filter and is smaller than the filter pore diameter.

JP 2010-166830 A JP 2008-200244 A

  However, since the inside of the sealed tank 41 is heated and heated by the heater 48, the energy for heating is large. Further, when evacuating, if the 60 L sealed tank 41 is evacuated and the water ring vacuum pump 42 is driven for 10 minutes, 30 L of tap water needs to be supplied during that time. The air introduced into the sealed tank 41 is air in the machine room, but when the air in the machine room contains a pollution source, the air containing the pollution source is drained together with the water supply during evacuation. There is a problem of leakage into the line 45. Further, in order to allow the waste water heated to 121 ° C. in the sealed tank 41 after sterilization to flow into the general drainage system, it is necessary to make the temperature lower than the heat resistance temperature of the general drainage system. In that case, there is a problem that a large amount of 400 L of tap water must be supplied from the cold water line 49.

  Accordingly, an object of the present invention is to provide a drainage sterilization system that can solve the above problems, reduce the heating energy and the amount of water used, and can prevent leakage of contamination sources contained in the air during vacuum exhaust.

  In order to achieve the above object, the first aspect of the present invention provides a wastewater which is sterilized by keeping the wastewater in the sealed tank at a high temperature and high pressure after the wastewater in the drainage tank is evacuated and introduced into the sealed tank. In the sterilization system, a water-sealed vacuum pump is connected to the sealed tank, a storage tank for storing treated water after sterilization treatment is connected to the sealed tank via a drainage line, and the sterilization treatment is performed on the drainage line. Waste water heating heat exchanger that exchanges heat between the treated water and the waste water in the waste water tank, and the treated water circulation that supplies and circulates the treated water in the storage tank to the water-sealed vacuum pump. A drainage sterilization system characterized by connecting lines.

  The invention according to claim 2 is the drainage sterilization system according to claim 1, wherein the storage tank is formed in a closed type and has a volume 5 to 10 times that of the closed tank.

  According to a third aspect of the present invention, the storage tank is connected to a water discharge line having an upper end opened at an upper portion in the storage tank and extended from a lower portion of the storage tank to the outside, and a gas phase formed at the upper end of the water discharge line. The drainage sterilization system according to claim 2, wherein the unit and the closed tank are connected by an air supply / discharge line.

  According to a fourth aspect of the present invention, the drainage tank is formed in a volume 3 to 6 times that of the sealed tank, and the drainage tank is provided with a drainage heating circulation for supplying and draining the drainage to the drainage heating heat exchanger. It is a wastewater sterilization system in any one of Claims 1-3 to which a line is connected.

  According to a fifth aspect of the present invention, the treated water in the storage tank is disposed between the treated tank circulation line extending from the storage tank to the water-sealed vacuum pump and the drainage line upstream of the wastewater heating heat exchanger. It is a wastewater sterilization system in any one of Claims 1-4 to which the heat recovery line which supplies and circulates to the said heat exchanger for wastewater heating through a line is connected.

  The invention according to claim 6 is the heating apparatus according to any one of claims 1 to 5, wherein a heating heat exchanger for heating a supply solution such as a culture solution is connected to a drainage line downstream of the wastewater heating heat exchanger. It is a wastewater sterilization system of crab.

  The present invention evacuates the inside of a sealed tank with a water-sealed vacuum pump and introduces waste water into the sealed tank to sterilize it at a high temperature and high pressure. By supplying and circulating, water supply such as tap water can be reduced. In addition, when draining the treated water after sterilization from the sealed tank to the storage tank, the heat energy can be reduced by exchanging heat with the wastewater in the wastewater tank before treatment to recover the heat and cooling the treated water. The outstanding effect that the amount of water supply, such as tap water for performing, can be reduced is exhibited.

It is a figure which shows one embodiment of this invention. It is a figure which shows a prior art example.

  A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 is a diagram showing an embodiment of a wastewater sterilization system of the present invention.

  In FIG. 1, reference numeral 10 is provided in a hazard management area such as a genetically modified plant factory or medical facility, and used culture fluid used in the genetically modified plant factory or the like, drainage water such as drain water after steam sterilization in a medical facility or the like. (Water to be sterilized) A drainage tank for storing Wd. Although not shown in the drawing, a heat insulating material is attached to the outer periphery to form a highly heat-insulating drainage tank 10. The drainage tank 10 is supplied with drainage Wd continuously or intermittently from the line 11 and stores it. When the drainage Wd is stored in the drainage tank 10, a large contamination source having a particle size of 100 μm or more contained in the drainage is removed in advance by a filter.

  A suction line 12 is connected to the drain tank 10. The suction port of the suction line 12 is provided so as to be located in the drainage Wd in the drainage tank 10, and from the inside of the factory where the drainage tank 10 is provided, the machine room MR which is a hazard management area surrounded by the two-dotted line shown in the figure And connected to the sealed tank 13. The drain tank 10 may be provided in the machine room MR in addition to being provided in a hazard management area such as a plant factory.

  The sealed tank 13 is connected to the storage tank 15 via the drain line 14. The storage tank 15 is a highly heat-insulating storage tank 15 to which a heat insulating material is attached in the same manner as the drainage tank 10.

  An inlet side opening / closing valve 16 is connected to the suction line 12, and an outlet side opening / closing valve 17 is connected to the drainage line 14. The drain tank 10 is formed in a volume 3 to 6 times that of the sealed tank 13, and the storage tank 15 is formed in a volume 5 to 10 times that of the sealed tank 13.

  The sealed tank 13 is provided with a heater 18 for heating the introduced waste water Wd to 121 ° C. or higher. A water-sealed vacuum pump 20 that evacuates the sealed tank 13 is connected to the sealed tank 13 via a suction line 19. The water-sealed vacuum pump 20 is configured by providing an impeller 20i eccentric in a circular casing 20c.

  The water-sealed vacuum pump 20 is connected to a treated water circulation line 21 for supplying and circulating treated water Wt after sterilization in the storage tank 15. The treated water circulation line 21 includes an upstream circulation line 21 a connecting the storage tank 15 and the water ring vacuum pump 20, and a downstream circulation line 21 b connected to the water ring vacuum pump 20 and the drain line 14. A treated water circulation pump 22 is connected to the line 21a, and a pump opening / closing valve 23 is connected to the downstream circulation line 21b.

  A drainage heating heat exchanger 24 for heating the drainage Wd in the drainage tank 10 is connected to the drainage line 14 on the downstream side of the outlet side opening / closing valve 17 and a heating heat exchanger 25 for heating the culture solution. Is connected.

  A drainage circulation line 27 having a drainage circulation pump 26 that supplies and circulates the wastewater Wd in the drainage tank 10 to the wastewater heating heat exchanger 24 is connected to the drainage tank 10 and the wastewater heating heat exchanger 24. The culture medium tank 28 and the heating heat exchanger 25 are connected to a culture medium circulation line 30 having a culture medium circulation pump 29 for supplying and circulating the culture medium in the culture medium tank 28 to the heating heat exchanger 25. Is done.

  The storage tank 15 is formed in a sealed type, and the lower end 14 a of the drain line 14 is provided so as to be immersed in the treated water Wt in the storage tank 15. The storage tank 15 is connected to a water discharge line 31 that has an upper end 31a that opens to an upper portion in the storage tank 15 and that extends from the lower portion of the storage tank 15 and extends from the machine room MR to the outside. A gas phase portion 15 g formed at the upper part of the upper end 31 a of the water discharge line 31 and the closed tank 13 are connected by an air supply / discharge line 32, and a supply / discharge on / off valve 33 is connected to the air supply / discharge line 32. Further, the water discharge line 31 is formed with a water sealing portion 31 s formed in a U shape so that air in the gas phase portion 15 is not discharged through the water discharge line 31.

  A water supply line 34 for supplying tap water or the like into the storage tank 15 is connected to the downstream drain line 14 of the heating heat exchanger 25, and a water supply valve 35 is connected to the water supply line 34.

  The storage tank 15 is provided with a thermometer 36 that detects the temperature of the treated water Wt. A heat recovery line 37 that branches from the upstream circulation line 21 a and supplies and circulates the treated water to the waste water heating heat exchanger 24 is connected to the upstream circulation line 21 a of the treated water circulation line 21. A heat recovery on-off valve 38 is connected to the stub. The heat recovery on-off valve 38 is controlled to open and close by the detection value of the thermometer 36, and the drain circulation pump 26 and the culture medium circulation pump 29 are driven and controlled by the detection value of the thermometer 36. .

  Next, the sterilization process of the waste water Wd will be described.

  First, the closed tank 13 is evacuated by the water ring vacuum pump 20 with the inlet side opening / closing valve 16 and the outlet side opening / closing valve 17 closed.

  The vacuuming by the water-sealed vacuum pump 20 is performed by rotating the impeller 20i in the circular casing 20c so that the treated water Wt in the storage tank 15 enters the circular casing 20c via the upstream circulation line 21a. Then, the treated water is rotated by the impeller 20i, becomes annular due to centrifugal force in the circular casing 20c, and enters the sealed tank 13 via the suction line 19 from the intake port formed in the side wall of the circular casing 20c of the impeller 20i. The air inside is sucked and the air sucked from the exhaust port is discharged together with the treated water Wt to the storage tank 15 via the downstream circulation line 21b. In the storage tank 15, the treated water Wt and air are separated, and the air is stored in the gas phase portion 15g.

  This evacuation is performed for about 10 minutes, and the amount of treated water is 30 L. However, since the treated water Wt in the storage tank 15 is circulated and used, it is possible to prevent consumption of tap water and the like in large quantities.

  After evacuating the sealed tank 13, the water-sealed vacuum pump 20 and the treated water circulation pump 22 are stopped, and the inlet side opening / closing valve 16 is opened. As a result, the waste water Wd in the drain tank 10 is introduced into the sealed tank 13 through the suction line 12.

  After introducing the waste water Wd into the sealed tank 13, the inlet side on-off valve 16 is closed again, and the waste water Wd is heated to 121 ° C. by the heater 18. By heating, the closed tank 13 rises to a saturated water vapor pressure (about 0.2 MPa), and by maintaining this high temperature and high pressure state for about 20 minutes, contaminant sources such as plant fragments and cells in the wastewater are inactivated and sterilized. The

  After the sterilization, the outlet side opening / closing valve 17 is opened, and the water is discharged to the storage tank 15 through the drain line 14 by the pressure in the sealed tank 13. At this time, the drainage circulation pump 26 is driven, and the wastewater Wd in the drainage tank 10 is caused to flow through the drainage circulation line 27 to the wastewater heating heat exchanger 24, whereby the sterilized treated water Wt flowing through the drainage line 14 and The heat is exchanged, and the heat is recovered in the highly heat-insulating drain tank 10.

  After all the sterilized treated water Wt in the sealed tank 13 has been discharged into the storage tank 15, the outlet side open / close valve 17 is closed and the sealed tank 13 is evacuated again by the water-sealed vacuum pump 20. .

  At this time, when the temperature of the treated water Wt in the storage tank 15 is detected by the thermometer 36 and the temperature of the treated water Wt in the storage tank 15 is high, before evacuating with the water-sealed vacuum pump 20, Alternatively, the waste water heating is performed by driving the treated water circulation pump 22 simultaneously with evacuation, opening the heat recovery on-off valve 38, and flowing the treated water Wt from the upstream circulation line 21a to the drain line 14 via the heat recovery line 37. The waste heat Wd in the drain tank 10 can be heated by the heat exchanger 24 for heat recovery.

  Thus, by recovering the heat of the high-temperature treated water discharged from the sealed tank 13 to the waste water before treatment, the temperature of the drained water introduced into the sealed tank 13 is sufficiently higher than room temperature (about 60 to 80 ° C.). Therefore, the heating energy in the heater 18 can be reduced.

  Further, as described above, after the sealed tank 13 is evacuated, while the waste water Wd introduced into the sealed tank 13 is treated at high temperature and high pressure by the heater 18, the culture solution circulation pump 29 is driven to circulate the culture solution. By supplying and circulating the culture solution to the heating heat exchanger 25 in the line 30, further heat recovery can be performed by heating the culture solution.

  In this heat recovery, the volume of the drainage tank 10 is 3 to 6 times the volume of the closed tank 13, and the heat of the treated water Wt heated to 121 ° C. in the closed tank 13 is drained. Even if the waste water Wd in the tank 10 is recovered, the temperature of the waste water Wd is about 60 to 80 ° C. and does not rise excessively.

  In the storage tank 15, the air in the sealed tank 13 is accumulated in the gas phase portion 15 g when the water-sealed vacuum pump 20 is evacuated, but the storage tank 15 is 5 to 10 times the volume of the sealed tank 13. Since the volume of the gas phase portion 15g is about twice the volume of the sealed tank 13, evacuation can be performed without any trouble.

  The treated water Wt after sterilization at high temperature and pressure is discharged to the storage tank 15 by the pressure of the sealed tank 13, but the pressure in the sealed tank 13 decreases with the discharge, and the pressure of the gas phase portion 15g of the storage tank 15 After the same, by opening the supply / discharge on / off valve 33 of the air supply / discharge line 32, the treated water Wt in the sealed tank 13 flows down to the storage tank 15 by gravity, and at the same time, air in the gas phase section 15g. Is introduced into the sealed tank 13 through the air supply / discharge line 32. Both the sealed tank 13 and the storage tank 15 are sealed, and the air only moves between the sealed tank 13 and the storage tank 15, and even if a contamination source is included in the air taken in from the machine room MR, the air remains outside. There is no leakage.

  When the liquid level of the treated water Wt in the storage tank 15 rises from the upper end 31a of the water discharge line 31, the treated water Wt is discharged from the machine room MR to the outside through the water discharge line 31.

  Before the sterilization process, since the storage tank 15 is empty, tap water or the like is supplied from the water supply line 34. When the treated water Wt is discharged from the storage tank 15 through the water discharge line 31 to the outside, if the temperature of the treated water Wt is excessively high, the temperature is detected by the thermometer 36 and stored in the storage tank 15. Supply water appropriately.

DESCRIPTION OF SYMBOLS 10 Drain tank 13 Sealed tank 14 Drain line 15 Storage tank 20 Water-sealed vacuum pump 21 Treated water circulation line 24 Heat exchanger for drainage heating

Claims (6)

  In a drainage sterilization system that evacuates the drainage water in the drainage tank and introduces it into the sealed tank, and then sterilizes the drainage by keeping the drainage in the sealed tank at high temperature and high pressure, a water-sealed vacuum pump is installed in the sealed tank. A drainage tank connected to a storage tank for storing treated water after sterilization treatment through the drainage line, and exchanging heat between the treated water after sterilization treatment and the wastewater in the drainage tank. A drainage sterilization system, wherein a heat exchanger for heating is connected, and a treated water circulation line for supplying and circulating the treated water in the storage tank to the water-sealed vacuum pump is connected to the storage tank.   The drainage sterilization system according to claim 1, wherein the storage tank is formed in a closed type and has a volume 5 to 10 times that of the closed tank.   The storage tank is connected to a water discharge line having an upper end opened at an upper portion in the storage tank and extended from the lower portion of the storage tank to the outside, and a gas phase portion formed at the upper end of the water discharge line and the sealed tank The drainage sterilization system according to claim 2 connected by an air supply / discharge line.   The drainage tank is formed to have a volume 3 to 6 times that of the sealed tank, and a drainage heating circulation line for supplying and circulating drainage to the drainage heating heat exchanger is connected to the drainage tank. The wastewater sterilization system in any one of 1-3.   Between the treated water circulation line extending from the storage tank to the water-sealed vacuum pump and the drainage line upstream of the wastewater heating heat exchanger, the treated water in the storage tank is heated via the drainage line. The drainage sterilization system according to any one of claims 1 to 4, wherein a heat recovery line that is supplied and circulated to the heat exchanger is connected.   The drainage sterilization system according to any one of claims 1 to 5, wherein a heating heat exchanger for heating a supply liquid such as a culture solution is connected to a drainage line on the downstream side of the wastewater heating heat exchanger. .

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