JP2023172545A - liquid supply device - Google Patents

Abstract

To efficiently cool or heat circulating liquid and supply the same to a use point.SOLUTION: A liquid supply device 1 includes: a tank 2 that stores liquid; a supply line L21 that supplies the liquid from the tank 2 to a use point 3; a pump 21 that is provided in the supply line L21 and circulates the liquid in the tank 2 to the supply line L21; a heat exchanger 22 that is provided in the supply line L21 on a downstream side of the pump 21 and cools or heats the liquid supplied to the use point 3 and used, to a temperature different from that of the liquid in the tank 2; and a reflux line L22 that refluxes liquid that is not used at the use point 3 out of the liquid supplied to the use point 3 through the supply line L21 to the supply line L21 on an upstream side of the pump 21.SELECTED DRAWING: Figure 1

Description

The present invention relates to a liquid supply device.

As a device that supplies purified water used in pharmaceutical manufacturing to the point of use, in order to suppress the generation of viable bacteria due to stagnation of purified water, the system is designed to supply water between the tank and the point of use, regardless of whether there is demand at the point of use. There are known devices that perform a circulation operation in which purified water is constantly circulated (see, for example, Patent Documents 1 and 2).

Japanese Patent Application Publication No. 2006-095479 Japanese Patent Application Publication No. 2017-196587

Some of these devices are equipped with a heat exchanger with a cooling or heating mechanism on the circulation path in order to meet the required temperature at the point of use, which is set lower or higher than room temperature. . In this case, purified water that has been cooled or heated to the required temperature at the point of use flows back into the tank that stores purified water, and is replenished with room-temperature purified water as needed. The temperature of purified water deviates from the required temperature at the point of use. And cooling or heating the purified water in such a tank to the required temperature at the point of use leads to unnecessary energy consumption.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a liquid supply device that efficiently cools or heats circulating liquid and supplies it to a point of use.

In order to achieve the above-mentioned object, the liquid supply device of the present invention includes a tank for storing liquid, a supply line for supplying the liquid from the tank to a point of use, and a supply line for supplying the liquid in the tank to the supply line. A heat exchanger installed in the supply line downstream of the pump to cool or heat the liquid supplied to the point of use to a different temperature than the liquid in the tank; It has a reflux line for refluxing liquid that is not used at the use point among the liquid supplied to the use point to the supply line on the upstream side of the pump.

According to such a liquid supply device, since it is possible to circulate the liquid without using a tank, the circulating liquid can be cooled or heated with the minimum necessary energy.

As described above, according to the present invention, the circulating liquid can be efficiently cooled or heated and supplied to the point of use.

1 is a schematic diagram showing the configuration of a purified water supply device according to an embodiment of the present invention.

Embodiments of the present invention will be described below with reference to the drawings. In this specification, as the liquid supply device of the present invention, a purified water supply device that supplies purified water used in pharmaceutical manufacturing to a point of use is exemplified, but the present invention is not limited to this, and for example, It can also be applied to devices that supply water (liquid) such as deionized water, ultrafiltrated water (purified water or deionized water treated with an ultrafiltration membrane), and water for injection to points of use. .

FIG. 1 is a schematic diagram showing the configuration of a purified water supply device according to an embodiment of the present invention. Note that the illustrated configuration of the purified water supply device is merely an example, and does not limit the present invention.

The purified water supply device 1 includes a tank 2 that stores purified water, a normal temperature water supply section 10, and a low temperature water supply section 20. In this embodiment, two types of required temperatures at use point 3 are set: room temperature (for example, 25° C.) and lower temperature (for example, 5° C.). Therefore, although the details will be described later, the normal temperature water supply section 10 is configured to supply the purified water in the tank 2 to the use point 3 as it is at room temperature, and the low temperature water supply section 20 is configured to supply the purified water in the tank 2 to the point of use 3. It is configured to be cooled to a temperature lower than room temperature and supplied to the use point 3. Below, in order to distinguish between the two types of purified water supplied to use point 3, purified water at room temperature may be referred to as "normal temperature water" and purified water at low temperature may be referred to as "low temperature water." Furthermore, the purified water supply device 1 has a control section (control means) 4 that controls the operation of the purified water supply device 1.

The room temperature water supply unit 10 includes a room temperature water circulation line L10 that circulates room temperature water, and a room temperature water pump 11 provided in the room temperature water circulation line L10. The room temperature water circulation line L10 connects the tank 2 and the inlet 3a of the use point 3, and the room temperature water supply line L11, in which the room temperature water pump 11 is provided, connects the outlet 3b of the use point 3 and the tank 2. It includes a reflux line L12. Note that the use point 3 is provided with a room temperature water supply line L1 connected to the room temperature water circulation line L10 via an on-off valve V1. The number of room temperature water supply lines L1 is not limited to one, and may be plural.

With this configuration, the room temperature water in the tank 2 is supplied to the use point 3 by the room temperature water pump 11 through the room temperature water supply line L11, and the room temperature water that is not used at the use point 3 is supplied through the room temperature water return line L12. It is refluxed to tank 2. In this way, a circulation operation is performed in which room temperature water is circulated through the tank 2, and the room temperature water is consumed at the use point 3 as necessary.

The low temperature water supply unit 20 includes a low temperature water circulation line L20 that circulates low temperature water, a low temperature water pump 21 provided in the low temperature water circulation line L20, and a heat exchanger 22 also provided in the low temperature water circulation line L20. There is. The low-temperature water circulation line L20 connects the tank 2 and the inlet 3c of the use point 3, and connects the low-temperature water supply line L21 with a low-temperature water pump 21 and the heat exchanger 22, the outlet 3d of the use point 3, and the low-temperature water It includes a low-temperature water recirculation line L22 that connects to a low-temperature water supply line L21 on the upstream side of the pump 21. The heat exchanger 22 has a function of cooling purified water flowing through the low-temperature water supply line L21 to a predetermined temperature to generate low-temperature water. Note that the use point 3 is provided with a low-temperature water supply line L2 connected to the low-temperature water circulation line L20 via an on-off valve V2. The number of low-temperature water supply lines L2 is not limited to one, and may be plural.

With this configuration, the low-temperature water sent by the low-temperature water pump 21 and cooled to a predetermined temperature by the heat exchanger 22 is supplied to the use point 3 through the low-temperature water supply line L21, and is not used at the use point 3. The low-temperature water is returned to the low-temperature water supply line 21 through the low-temperature water return line L22. In this way, a circulation operation is performed in which low-temperature water is circulated without going through the tank 2, and the low-temperature water is consumed at the use point 3 as necessary. In such a low-temperature water circulation operation, the low-temperature water from the low-temperature water reflux line L22 is not returned to the tank 2 as described above, but is combined with room-temperature water supplied from the tank 2 as needed to generate heat. It is supplied to the exchanger 22. That is, when the flow rate of the low temperature water supply line L21 changes depending on the amount used at the use point 3, room temperature water is supplied from the tank 2 to the low temperature water supply line L21 accordingly, and the room temperature water is supplied to the low temperature water reflux line. The low temperature water from L22 is combined and supplied to the heat exchanger 22. Note that the room temperature water is supplied from the tank 2 using the pressure difference between the pressure inside the tank 2 and the pressure inside the low temperature water supply line L21, or the suction pressure of the pump. In this way, the temperature rise of the low-temperature water supplied to the heat exchanger 22 can be minimized, and the energy for generating the low-temperature water can be minimized. This is preferable because a heat exchanger 22 with a small cooling capacity can be used, leading to cost reduction.

The room temperature water reflux line L12 is provided with an ultraviolet sterilizer 12 and a heat exchanger (not shown). The ultraviolet sterilizer 12 is used to sterilize the room temperature water flowing through the room temperature water return line L12 by irradiating it with ultraviolet light. The heat exchanger is used in a hot water sterilization process that is carried out periodically between normal operations, and heats the purified water circulating along the room temperature water circulation line L10 to a predetermined temperature or higher, for example, 80 to 90°C. The hot water is used to sterilize the tank 2 and the room temperature water circulation line L10. Note that the room temperature water circulation operation is performed even during periods when there is no demand for room temperature water at use point 3, such as at night or on holidays. As a result, the temperature of room temperature water may rise to exceed the required temperature at point of use 3. Therefore, the heat exchanger for hot water sterilization described above may be provided with a cooling function, and a heat exchanger with a separate cooling function may be provided in the room temperature water circulation line L10.

An on-off valve V11 is provided on the downstream side of the ultraviolet sterilizer 12 in the room-temperature water return line L12, and a room-temperature water discharge line L13 is provided between the on-off valve V11 and the ultraviolet sterilizer 12 via the on-off valve V12. It is connected. During the circulation of room temperature water, the on-off valve V11 of the room temperature water recirculation line L12 is opened and the on-off valve V12 of the room temperature water discharge line L13 is closed. room temperature water tends to accumulate. On the other hand, when discharging room temperature water, the on-off valve V11 of the room temperature water reflux line L12 is closed and the on-off valve V12 of the room temperature water discharge line L13 is opened. Room temperature water tends to accumulate in the area from the connection point to the on-off valve V11. In order to eliminate the influence of such dead legs as much as possible, it is preferable, for example, that the distance from the center of the main pipe to the closing mechanism at the tip of the branch pipe be within six times the inner diameter of the branch pipe. That is, the distance from the center of the room temperature water recirculation line L12 to the closing position of the on-off valve V12 at the connection point with the room temperature water discharge line L13 is preferably within six times the inner diameter of the room temperature water discharge line L13. Similarly, the distance from the center of the room temperature water discharge line L13 to the closing position of the on-off valve V11 at the connection point with the room temperature water reflux line L12 is also preferably within six times the inner diameter of the room temperature water reflux line L12.

The low temperature water reflux line L22 is provided with an ultraviolet sterilizer 23, similar to the room temperature water reflux line L12. The ultraviolet sterilizer 23 is used to sterilize the low-temperature water flowing through the low-temperature water recirculation line L22 by irradiating it with ultraviolet rays. However, the propagation rate of living bacteria is slower in low-temperature water than in room-temperature water, and if the room-temperature water in the tank 2, which is also the water intake source for the low-temperature water supply section 20, has already been sterilized, it is not necessary to sterilize the low-temperature water with ultraviolet rays. Since it is not necessary, the ultraviolet sterilizer 23 may be omitted. Further, in the low temperature water circulation line L20, the same hot water sterilization process as in the case of the room temperature water circulation line L10 is performed. Therefore, in order to generate hot water by heating the purified water circulating along the low-temperature water circulation line L20 above the predetermined temperature, the heat exchanger 22 described above may have a heating function, and a separate heating function may be provided. A heat exchanger with a heating function may be provided in the low temperature water circulation line L20. Note that since the low temperature water supply section 10 is always provided with a heat exchanger 22 for cooling, even if the low temperature water circulation operation continues for a long period of time, low temperature There is no concern about water temperature rising.

Further, the low temperature water recirculation line L22 is provided with a pressure sensor 24, a temperature sensor 25, and a flow rate sensor 26. These are used not only for the purpose of grasping the usage status of low-temperature water at the use point 3, but also for controlling the operation of the purified water supply device 1 by the control unit 4, as will be described later.

The low temperature water reflux line L22 is connected to the low temperature water supply line L21 via the on-off valve V21, and is connected to the upstream side of the connection point, specifically, at a position close to the downstream end of the low temperature water reflux line L22. A low temperature water discharge line L23 is connected to via an on-off valve V22. During low-temperature water circulation, the on-off valve V21 of the low-temperature water recirculation line L22 is opened, and the on-off valve V22 of the low-temperature water discharge line L23 is closed (that is, the on-off valves V21 and V22 as flow path switching means are in the first The low-temperature water reflux line L22 and the low-temperature water supply line L21 are connected to each other. Therefore, low-temperature water tends to stay in the portion of the low-temperature water discharge line L23 on the upstream side of the on-off valve V22. On the other hand, when low-temperature water is drained, the on-off valve V21 of the low-temperature water recirculation line L22 is closed, and the on-off valve V22 of the low-temperature water discharge line L23 is opened (that is, the on-off valves V21 and V22 as flow path switching means are 2), the low temperature water reflux line L22 and the low temperature water discharge line L23 are communicated with each other. Therefore, low-temperature water tends to accumulate in a portion of the low-temperature water recirculation line L22 from the connection point with the low-temperature water discharge line L23 to the on-off valve V21 and a portion downstream of the on-off valve V21. In order to eliminate the influence of such dead legs as much as possible, as described above, it is preferable that the distance from the center of the main pipe to the closing mechanism at the end of the branch pipe be within six times the inner diameter of the branch pipe. That is, the distance from the center of the low temperature water recirculation line L22 at the connection point with the low temperature water discharge line L23 to the closing position of the on-off valve V22 is preferably within six times the inner diameter of the low temperature water discharge line L23. Similarly, the distance from the center of the low temperature water supply line L21 at the connection point with the low temperature water reflux line L22 to the closing position of the on-off valve V21, and the distance from the center of the low temperature water discharge line L23 at the connection point with the low temperature water reflux line L22. It is also preferable that the distance to the closed position of the on-off valve V22 is within six times the inner diameter of the low temperature water recirculation line L22.

A purified water supply line L3 is connected to the tank 2, and for example, purified water is supplied from a purified water production device (not shown) according to the water level in the tank 2 detected by a water level sensor (not shown). will be replenished. Specifically, when the water level in the tank 2 falls below a predetermined lower limit water level, purified water is supplied to the tank 2 through the purified water supply line L3, and when the water level in the tank 2 reaches a predetermined upper limit water level, the tank 2 Purified water supply to the area will be suspended.

The control unit 4 includes an inverter (not shown) that controls the rotation speed of the low-temperature water pump 21, and controls the rotation speed of the low-temperature water pump 21 during normal operation of the purified water supply device 1 (purified water circulation operation). By doing so, the flow rate control of low-temperature water is executed. Specifically, based on the flow rate of low-temperature water detected by the flow rate sensor 26, the rotation speed of the low-temperature water pump 21 is controlled so that the flow rate of low-temperature water flowing through the low-temperature water recirculation line L22 is constant. By controlling the flow rate of low-temperature water in this manner, the flow rate of low-temperature water supplied to the heat exchanger 22 can be stabilized, the cooling capacity of the heat exchanger 22 can be stably demonstrated, and a stable temperature can be maintained at the point of use 3. This makes it possible to supply low-temperature water. The pressure sensor 24 may be used instead of the flow rate sensor 26 as the low-temperature water flow rate detection means, and therefore the rotation speed of the low-temperature water pump 21 may be controlled so that the detected pressure is constant. Further, the low temperature water flow rate adjustment means is not limited to the low temperature water pump 21, and a flow rate adjustment valve may be provided in the low temperature water recirculation line L22. Although not described in detail here, the control unit 4 controls the rotation speed of the room temperature water pump 11 based on the detection result of a flow rate sensor or a pressure sensor (none of which are shown) provided in the room temperature water return line L12. Also executes room temperature water flow rate control to maintain a constant flow rate of room temperature water flowing through the room temperature water reflux line L12.

During the low temperature water circulation operation, the return pressure of the low temperature water recirculation line L22 (the pressure detected by the pressure sensor 24) is set such that the low temperature water recirculation line L22 is negative so that room temperature water can be smoothly sent from the tank 2 to the pump 21. Adjusted to avoid pressure. As a result, room temperature water is automatically supplied from the tank 2 to the low temperature water supply line L21 without installing a valve or pump between the tank 2 and the confluence of the low temperature water supply line L21 and the low temperature water reflux line L22. Supplied. The detected pressure of the pressure sensor 24 is preferably adjusted to a range of 0.01 to 0.2 MPa, and more preferably adjusted to a range of 0.05 to 0.15 MPa, for example. This is because if you try to control the pressure detected by the pressure sensor 24 to less than 0.01 MPa, the control will not be able to keep up with the use of low temperature water at use point 3, and there is a possibility that the low temperature water reflux line L22 will become a negative pressure. This is because there is. In addition, if the return pressure of the low temperature water recirculation line L22 becomes too high, room temperature water cannot be smoothly sent from the tank 2 to the pump 21, which may ultimately disturb the pressure detected by the pressure sensor 24. . However, the ease with which room-temperature water can be sent from the tank 2 to the pump 21 varies depending on the water head pressure from the tank 2 and the pressure loss of the on-off valve V21 (opening degree of the on-off valve V21), so the above-mentioned pressure range is limited to the present invention. It is not intended to limit.

By the way, in the purified water supply apparatus 1 that handles purified water used for pharmaceutical manufacturing, the system of the purified water supply apparatus 1 including the tank 2 and each circulation line L10, 20 is cleaned in order to prevent the generation of bacteria and microorganisms. Sterilization by steam is preferred. For this purpose, a steam introduction line (steam introduction means) L4 for introducing steam is connected to the tank 2, and the control unit 4 periodically performs sterilization processing using steam between normal operations. This steam sterilization process will be explained below.

When the steam sterilization process is started, the operation (circulation of purified water) of the purified water supply device 1 is stopped, and a drainage operation is performed to discharge the purified water in the system to the outside. Specifically, when the operation of the heat exchanger 22 is stopped and purified water was used at the use point 3 immediately before, the on-off valves V1 and V2 of the water supply lines L1 and L2 are closed. Then, the on-off valve (not shown) of the purified water replenishment line L3 is closed to stop the supply of purified water to the tank 2, and the on-off valve V11 of the room temperature water reflux line L12 and the on-off valve V21 of the low-temperature water reflux line L22 are closed. At the same time, the on-off valve V12 of the room-temperature water discharge line L13 and the on-off valve V22 of the low-temperature water discharge line L23 are opened. As a result, the purified water stored in the tank 2 is discharged to the outside from the room temperature water circulation line L10 through the room temperature water discharge line L13 by the operation of the pumps 11 and 21, and similarly from the low temperature water circulation line L20 to the low temperature water discharge line L23. is discharged to the outside through. After that, when the water level in the tank 2 drops to a certain level, the pumps 11 and 21 stop operating, and clean air is introduced into the tank 2, and the purified water in each circulation line L10 and L20 is also pushed out by the pressure. is discharged outside.

When the purified water in the system is discharged to the outside, the on-off valve V11 of the room temperature water reflux line L12 and the on-off valve V21 of the low-temperature water reflux line L22 are opened, and at the same time, the on-off valve V3 of the steam introduction line L4 is opened. be done. In this way, steam is introduced into each circulation line L10, 20 through the tank 2, and the inside of the system of the purified water supply device 1 is sterilized. Note that the steam at this time is introduced at a temperature and pressure that can appropriately sterilize the inside of the system. For example, in order to introduce steam at 121° C. or higher, a pressure of about 0.11 MPa in gauge pressure (0.21 MPa in absolute pressure) is sufficient. In addition, when introducing steam at 121°C or higher, if the length of piping to be steam sterilized is long, if the tank 2 to be steam sterilized is large, if there are many devices to be steam sterilized, each circulation line If there are many pipes branching from L10 and L20, or if you want to reliably supply steam to a location far from the steam supply source, the pressure should be adjusted to a gauge pressure of 0.15 to 0.19 MPa. good. On the other hand, it is difficult to maintain the system pressure when the on-off valves V21 and V22 are open, so if necessary, only steam condensed water is discharged to the secondary side of the on-off valves V21 and V22 to maintain the system pressure. A perforated or grooved valve may be installed for this purpose.

After the steam is introduced for a certain period of time, the on-off valve V3 of the steam introduction line L4 is closed, and the introduction of steam is stopped. When the steam sterilization step is completed in this way, the on-off valve (not shown) of the purified water supply line L3 is opened and supply of purified water to the tank 2 is started, and the room temperature water supply section 10 and the low temperature water supply section 20 respectively supply purified water. Circulation operation is resumed. Specifically, in the room temperature water supply unit 10, the on-off valve V12 of the room temperature water discharge line L13 is closed and the room temperature water pump 11 is operated, so that the purified water in the tank 2 is discharged from the room temperature water supply line L11 to room temperature water. It is refluxed to the tank 2 through the reflux line L12. In this way, the circulating operation of purified water (normal temperature water) along the normal temperature water circulation line L10 is restarted. On the other hand, in the low-temperature water supply unit 20, after an air purge operation for discharging the air in the low-temperature water circulation line L20 to the outside is performed, the purified water circulation operation is restarted. Specifically, the on-off valve V21 of the low temperature water reflux line L22 is closed and the low temperature water pump 21 is activated, so that after the purified water in the tank 2 flows from the low temperature water supply line L21 to the low temperature water reflux line L22. , and is discharged to the outside through the low-temperature water discharge line L23 without being returned to the low-temperature water supply line L21. Due to such drainage of purified water, the air that filled the low temperature water circulation line L20 after the end of the steam sterilization process is discharged to the outside together with the purified water. Thereafter, the on-off valve V21 of the low-temperature water reflux line L22 is opened, and the on-off valve V22 of the low-temperature water discharge line L23 is closed, so that the purified water flowing through the low-temperature water reflux line L22 is returned to the low-temperature water supply line 21. Then, purified water is circulated along the low temperature water circulation line L20.

However, at this time, if the air in the low-temperature water circulation line L20 is not sufficiently removed, the air may flow back to the low-temperature water pump 21, causing cavitation and damaging the low-temperature water pump 21. Furthermore, even if the circulation of purified water is restarted and the heat exchanger 22 is operated in a state where the air in the low-temperature water circulation line L20 has not been sufficiently removed, it will take a considerable amount of time before the temperature of the purified water (low-temperature water) stabilizes. This takes time and consumes unnecessary energy and refrigerant.

Therefore, the purified water at this time is not drained until it is confirmed that all the air in the low temperature water circulation line L20 has been removed. It is preferable to continue this process until it is confirmed that the condition is satisfied. Thereby, the purified water can be efficiently cooled by the subsequent operation of the heat exchanger 22, and the time (startup time) until the temperature of the purified water (low-temperature water) stabilizes can be shortened. . Whether or not the inside of the low-temperature water reflux line L22 is filled with purified water depends, for example, on whether the pressure or flow rate of the purified water flowing through the low-temperature water reflux line L22 has reached a steady state. The determination can be made based on whether a predetermined period of time has elapsed since the detection value of the sensor 24 or the flow rate sensor 26 became equal to or greater than a predetermined value. Note that the full-water detection means for the low-temperature water recirculation line L22 is not limited to the pressure sensor 24 or the flow rate sensor 26, and the temperature sensor 25 may be used. That is, it may be determined from the temperature change of the purified water detected by the temperature sensor 25 whether or not the inside of the low temperature water reflux line L22 is filled with purified water.

In this manner, when it is confirmed that the inside of the low-temperature water circulation line L20 is filled with purified water, the air purge operation of the low-temperature water circulation line L20 is completed, and the operation is switched to the circulation operation as described above. Then, the heat exchanger 22 operates to start cooling the purified water, and when the temperature of the circulating purified water (low-temperature water) becomes stable, the low-temperature water circulation operation along the low-temperature water circulation line L20 is restarted, That is, the normal operation of the purified water supply device 1 is restarted.

Note that if piping restrictions such as suppression of purified water retention permit, after the steam sterilization process is completed, the low temperature water supply unit 20 uses purified water flowing through the low temperature water reflux line L22 to vent air in the low temperature water circulation line L20. Instead of discharging the water to the outside, the air in the low-temperature water circulation line L20 may be returned to the tank 2 by circulating it back to the tank 2.

In the above-described embodiment, the case where two types of purified water, one at room temperature and one at a lower temperature, are supplied to the point of use is explained as an example, but the present invention is not limited to this, and two types of purified water, one at room temperature and one at a higher temperature, are supplied to the point of use. It is also applicable when supplying purified water to points of use. That is, the liquid supply device of the present invention has a heat exchanger equipped with a heating mechanism instead of a low-temperature water supply section, and the circulating purified water is heated to a temperature higher than the temperature of the purified water in the tank (normal temperature). A high temperature water supply may be provided for heating and supplying the water to the point of use. In this case as well, the high-temperature water supply section has the same configuration as the low-temperature water supply section, thereby enabling circulation operation in which high-temperature purified water is circulated without going through a tank.

1 Purified water supply device (liquid supply device)
2 Tank 3 Point of use 4 Control section (control means)
10 Room temperature water supply section 11 Room temperature water pump 12 Ultraviolet oxidizer 20 Low temperature water supply section 21 Low temperature water pump 22 Heat exchanger 23 Ultraviolet oxidizer 24 Pressure sensor (flow rate detection means, full water detection means)
25 Temperature sensor (full water detection means)
26 Flow rate sensor (flow rate detection means, full water detection means)
L1, L2 Water supply line L3 Steam introduction line (steam introduction means)
L10 Room temperature water circulation line L11 Room temperature water supply line L12 Room temperature water reflux line L13 Room temperature water discharge line L20 Low temperature water circulation line L21 Low temperature water supply line L22 Low temperature water reflux line L23 Low temperature water discharge line V1 to V3, V11, V12 On-off valves V21, V22 On-off valve (flow path switching means)

Claims (11)

A tank for storing liquid,
a supply line that supplies liquid from the tank to the point of use;
a pump provided in the supply line;
a heat exchanger that is provided in the supply line downstream of the pump and cools or heats the liquid supplied to the point of use to a temperature different from that of the liquid in the tank;
A liquid supply device comprising: a reflux line for refluxing liquid that is not used at the use point among the liquids supplied to the use point through the supply line to the supply line upstream of the pump. The liquid supply device according to claim 1, further comprising a discharge line connected to the reflux line at a position close to a downstream end of the reflux line and discharging the liquid in the supply line and the reflux line to the outside. In order to perform a circulation operation in which the liquid flowing through the reflux line is refluxed to the supply line, the reflux line and the supply line are in communication with each other, and the liquid in the supply line and the reflux line is discharged. In order to perform a drainage operation to discharge outside from the line, or after the drainage operation is performed, liquid is supplied from the supply line to the reflux line to drain the air in the supply line and the reflux line to the discharge line. 3. The liquid supply device according to claim 2, further comprising flow path switching means that can be switched to a second state in which the reflux line and the discharge line communicate with each other in order to perform an air purge operation for discharging air from the reflux line to the outside. In the circulation operation, the liquid in the tank is supplied to the supply line by the pressure difference between the pressure in the tank and the pressure in the supply line, or by the suction pressure of the pump, and the liquid is refluxed from the reflux line. 4. The liquid supply device according to claim 3, wherein the liquid supply device is combined with the liquid supplied to the liquid. Claim 3, further comprising a control means for switching the flow path switching means from the second state to the first state when it is detected that the inside of the reflux line is filled with liquid during the air purge operation. Or the liquid supply device according to 4. The liquid according to claim 5, wherein the control means operates the heat exchanger to start the cooling or heating after switching the flow path switching means from the second state to the first state. Feeding device. 6. The liquid supply device according to claim 5, further comprising a full-water detection means that includes a flow rate sensor, a pressure sensor, or a temperature sensor and detects whether the inside of the reflux line is filled with liquid. a flow rate detection means for detecting the flow rate of the liquid flowing through the reflux line;
a flow rate adjustment means for adjusting the flow rate of the liquid flowing through the reflux line;
6. The control means controls the flow rate adjustment means so that the flow rate of the liquid flowing through the reflux line is constant based on the flow rate detected by the flow rate detection means during the circulation operation. liquid supply device. A heat exchanger that is installed in the supply line or the reflux line and heats the liquid flowing through the supply line or the reflux line to a predetermined temperature or higher to generate hot water for sterilizing the supply line and the reflux line. The liquid supply device according to any one of claims 1 to 4. Any one of claims 1 to 4, further comprising steam introduction means for introducing steam into the supply line and the reflux line through the tank in order to sterilize the tank, the supply line, and the reflux line. The liquid supply device according to item 1. another supply line supplying liquid from the tank to the point of use;
another pump provided in the other supply line;
5. Another reflux line for refluxing liquid not used at the point of use among the liquids supplied to the point of use through the other supply line to the tank. The liquid supply device described in .

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