JP3718055B2 - Operation control method of ozone circulation cleaning device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an operation control method for an ozone circulation cleaning apparatus, and more particularly to an operation control method suitable for reliably suppressing the adhesion and growth of microorganisms on a heat transfer surface of a heat exchange plate.
[0002]
[Prior art]
A conventional ozone circulation cleaning device for a plate heat exchanger is configured as shown in FIG. That is, a heat exchange unit 2 composed of an assembly of a plurality of heat exchange plates 1, 1 is inserted into the heat exchanger body 3, and the heat medium F enters the heat exchange plates 1, 1 from the inlet 2 A of the heat exchange unit 2. Are introduced and passed through, and the heat medium F is led out of the heat exchange unit 2 from the outlet 2B, and water W such as sewage, river water or seawater is passed inside the heat exchanger body 3, and this passage is performed. The water W and the heat medium F passing through the heat exchange plates 1 and 1 are indirectly heat-exchanged via the heat transfer surfaces of the heat exchange plates 1 and 1.
[0003]
A water supply pipe 4 is connected to the inlet 3 </ b> A of the heat exchanger body 3, a drain pipe 5 is connected to the outlet 3 </ b> B, a water cutoff valve 6 is interposed in the water supply pipe 4, and a water cutoff valve is connected to the drain pipe 5. 7 is interposed. The position immediately downstream of the water shutoff valve 6 in the water supply pipe 4 and the position immediately upstream of the water shutoff valve 7 in the drain pipe 5 are communicated with each other via the communication pipe 8. The communication pipe 8 is allowed to flow only from the first circulation valve 9 and the communication pipe 8 to the water supply pipe 4, and the second circulation valve 10 is constituted by a check valve that blocks the flow from the water supply pipe 4 to the communication pipe 8. Is installed. Accordingly, the circulation loop 11 including the water supply pipe 4, the inside of the heat exchanger body 3, the drain pipe 5 and the communication pipe 8 is formed by closing the water cutoff valves 6 and 7 and opening the first circulation valve 9. Can be configured. A circulation pump 12 is interposed in the communication pipe 8.
[0004]
On the other hand, the ozone generation source 14 communicates with the communication pipe 8 through the ozone supply pipe 15 and the ozone injection ejector 13. For this reason, by operating the circulation pump 12 and the ozone generation source 14 in a state where the circulation loop 11 is formed, ozone is injected (supplied) into the circulation loop 11 and the ozone-dissolved water can be circulated.
[0005]
On the other hand, since the apparent volume in the circulation loop 11 is increased by injecting ozone, the discharge pipe 18 in which the expansion tank 16 and the ozone decomposer 17 filled with activated carbon are connected in series from the communication pipe 8 is branched. The expansion tank 16 absorbs the volume increase, and the excess gas is led from the top of the expansion tank 16 to the ozonolysis device 17 and discharged. With such a configuration, the circulation loop 11 is opened to the atmosphere.
[0006]
By the way, the water shutoff valves 6 and 7 are opened, the first circulation valve 9 is closed, and water W such as sewage, river water or seawater is allowed to pass through the heat exchanger main body 3, and this passing water When W and the heat medium F passing through the heat exchange plates 1 and 1 are indirectly heat exchanged via the heat transfer surfaces of the heat exchange plates 1 and 1, sewage, river water, seawater, etc. Microorganisms contained in the water W may grow on the surface of each heat exchange plate 1, 1, that is, the heat transfer surface, to produce microbial dirt called slime. Lowers the heat exchange efficiency.
[0007]
Accordingly, the water shutoff valves 6 and 7 are closed, the first circulation valve 9 is opened, and the circulation pump 12 and the ozone generation source 14 are operated to inject ozone into the circulation loop 11, Ozone treatment that circulates dissolved water removes microbial soil called slime and suppresses the adhesion and growth of microorganisms on the heat transfer surface.
[0008]
According to the ozone circulation cleaning device of the plate type heat exchanger, it is relatively easy to save time and effort compared to the disinfecting cleaning, the stationary cleaning using chemicals called CIP or the stationary cleaning using hot water. In addition to removing microbial soil called slime, it is possible to suppress the adhesion and growth of microorganisms on the heat transfer surface.
[0009]
[Problems to be solved by the invention]
In this ozone circulation cleaning apparatus, the water shutoff valves 6 and 7 are opened, the first circulation valve 9 is closed, and water W such as sewage, river water or seawater is allowed to pass inside the heat exchanger body 3. In the state where heat is exchanged, a pressure corresponding to the use conditions is applied in the heat exchanger main body 3, and the heat exchanger main body 3 expands with a slight internal pressure. When performing ozone circulation cleaning, first, the water shutoff valves 6 and 7 are closed, then the first circulation valve 9 is opened to form the circulation loop 11, but the first circulation valve 9 is opened. Instantly, the water corresponding to the expansion of the heat exchanger body 3 overflows through the expansion tank 16 and the ozone decomposer 17, and the function of the expansion tank 16 is lost due to the full water and the ozone decomposition function due to the flooding of the ozone decomposer 17. There is a risk of causing loss. Moreover, even if the ozonolysis function of the ozonolysis device 17 is not lost, the dissolved residual ozone in the circulation loop 11 flows down from the water supply pipe 4 to the drain pipe 5 when the heat exchange after the ozone cleaning process is resumed. In some cases, it may adversely affect the water supply and drainage pipe system.
[0010]
Therefore, the present invention prevents the water corresponding to the volume of the heat exchanger body that has been expanded when the circulation loop is formed from overflowing through the expansion tank and the ozonolysis device, An ozone circulating cleaning device that avoids loss of function of the ozone decomposer and prevents dissolved residual ozone in the circulation loop from flowing from the water supply pipe to the drain pipe when resuming heat exchange after the ozone cleaning treatment. The object is to provide an operation control method.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, an operation control method of the ozone circulation cleaning apparatus according to the present invention includes a heat exchange unit including a plurality of heat exchange plates assembled in a heat exchanger body, The heat medium is sequentially introduced into and passed through each heat exchange plate from the inlet, and the heat medium is led out of the heat exchange unit from the outlet, and water is passed through the heat exchanger body. And a heat medium passing through the heat exchange plates are indirectly heat exchanged via the heat transfer surfaces of the heat exchange plates, and a water supply pipe connected to the inlet of the heat exchanger body, and the heat exchanger body A drain pipe connected to the outlet of the water supply pipe, a water cutoff valve interposed in each of the water supply pipe and the drain pipe, the water supply pipe downstream of the water cutoff valve and the drain pipe upstream of the water cutoff valve, And communication pipes that communicate with each other Circulating the water supply pipe, the inside of the heat exchanger body, the drain pipe, and the communication pipe by closing each water cutoff valve and opening a circulation valve interposed in the communication pipe A loop is formed, the circulation pump is operated, and ozone generated from an ozone generation source is supplied to the circulation loop to circulate ozone-dissolved water, and an expansion tank and an ozone decomposer are provided in series in the circulation loop. In the ozone circulation cleaning device for a plate heat exchanger provided with a branched discharge pipe, the water shutoff valve is closed, the relief valve is opened, and the internal pressure of the heat exchanger main body is opened. After releasing the volume of water that had been expanded, the relief valve was closed and then the circulation valve was opened to form a circulation loop. After the water was supplied from the water supply tank to the circulation loop, the circulation pump was turned on. Drive The ozone generated by the operation of the ozone source is supplied to the circulation loop, and after the ozone circulation cleaning by circulating the ozone-dissolved water is performed, the operation of the ozone source is stopped, and the ozone dissolved after the operation of the ozone source is stopped Continue to circulate water to decompose dissolved residual ozone, then stop the operation of the circulation pump, and open the drain valve provided in the circulation loop with the water supply from the water supply tank to the circulation loop stopped. After draining dirty water in the circulation loop, the drain valve is then closed and water is supplied from the water tank to the circulation loop, and then the circulation valve is closed and the water shutoff valve is opened. It is characterized by returning to a replaceable state.
[0012]
According to the present invention, after the water shutoff valve is closed, the relief valve is opened to release the volume of water that has been expanded by the internal pressure of the heat exchanger body, thereby expanding the volume. Water corresponding to a minute can be prevented from overflowing through the expansion tank and the ozonolysis device, and loss of function of the expansion tank and ozonolysis device can be avoided. In addition, after performing ozone circulation cleaning by circulation of ozone-dissolved water, the operation of the ozone generation source is stopped, and after the operation of the ozone generation source is stopped, the circulation of ozone-dissolved water is continued to decompose dissolved residual ozone. It is possible to prevent the dissolved residual ozone in the circulation loop from flowing down from the water supply pipe to the drain pipe.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an example of a configuration diagram applicable to the implementation of the present invention. In addition, the same code | symbol is attached | subjected to the part which is the same as that of the prior art example shown in FIG. 6, or an equivalent, and detailed description is abbreviate | omitted. In FIG. 1, an expansion relief pipe 19 is branched and provided at a position immediately upstream of the first circulation valve 9 in the communication pipe 8, and a relief valve 20 is interposed in the expansion relief pipe 19. The water supply tank 21 communicates with the discharge side of the circulation pump 12 in the communication pipe 8 through the water supply pipe 22, and the water supply pipe 22 only flows from the water supply tank 21 side to the water supply valve 23 and the communication pipe 8. And a check valve 24 that interrupts the flow from the communication pipe 8 to the water supply valve 23 is provided in series. Further, a drain pipe 26 provided with a drain valve 25 is branched from the communication pipe 8. In the figure, 27 indicates a gas-liquid separator, and 28 indicates an air vent valve.
[0014]
Next, the control method of the present invention will be described. As shown in FIG. 1, the water shutoff valves 6 and 7 are opened and the first circulation valve 9, the relief valve 20, the water supply valve 23 and the drain valve 25 are closed, and the heat exchanger main body 3 is opened. By passing water W such as sewage, river water or seawater, the passing water W and the heat medium F passing through the heat exchange plates 1 and 1 are passed through the heat transfer surfaces of the heat exchange plates 1 and 1. Indirect heat exchange.
[0015]
On the other hand, when it is desired to perform ozone cleaning regularly or periodically, a cleaning start signal is output. Based on the output cleaning start signal, the water shutoff valves 6 and 7 are closed as shown in FIG. 2, the relief valve 20 is opened, and the heat exchanger body 3 is moved by the internal pressure of the heat exchanger body 3. The expanded volume of water is allowed to escape within a predetermined time (T1). This prevents the water corresponding to the volume which has been expanded from overflowing through the expansion tank 16 and the ozonolysis device 17, thereby avoiding the loss of function of the expansion tank 16 and the loss of function of the ozonolysis device 17. be able to.
[0016]
When a predetermined time (T1) has elapsed, the relief valve 20 is closed as shown in FIG. 3 and the first circulation valve 9 is opened to form a circulation loop 11 and the water supply valve 23 is opened to supply water. Water is supplied from the tank 21 to the circulation loop 11 to fill the circulation loop 11 with water within a predetermined time (T2), and the circulation pump 12 is operated when the predetermined time (T2) has elapsed. The water supply from the water supply tank 21 to the circulation loop 11 is shut off even if the water supply valve 23 is open due to the influence of the discharge pressure due to the operation of the circulation pump 12.
[0017]
By continuing the operation of the circulation pump 12 for a predetermined time (T3), the air in the circulation loop 11 is vented from the path of the gas-liquid separator 27 and the air vent valve 28.
[0018]
When the predetermined time (T3) elapses, the operation of the ozone generation source 14 is started, ozone generated by the ozone generation source 14 is supplied to the circulation loop 11 within the predetermined time (T4), and ozone circulation is performed while circulating the ozone-dissolved water. Wash.
[0019]
When the predetermined time (T4) elapses, the operation of the ozone generation source 14 is stopped, and the ozone-dissolved water is circulated in the circulation loop 11 by the operation of only the circulation pump 12 for the predetermined time (T5). Thereby, the dissolved residual ozone in the circulation loop 11 is decomposed. When the predetermined time (T5) has elapsed, the operation of the circulation pump 12 is stopped.
[0020]
When the predetermined time (T5) has elapsed, the operation of the circulation pump 12 is stopped as described above, the water supply valve 23 is closed for a predetermined time (T6), and the drain valve 25 is opened as shown in FIG. Thereby, the cleaned dirty water in the circulation loop 11 is discharged.
[0021]
When the predetermined time (T6) has elapsed, the drain valve 25 is closed as shown in FIG. 5 and the water supply valve 23 is opened for a predetermined time (T7) to supply water to the circulation loop 11.
[0022]
When the predetermined time (T7) elapses, the first circulation valve 9 and the water supply valve 23 are closed, and the water cutoff valves 6 and 7 are opened, so that the state shown in FIG. The internal passing water W and the heat medium F passing through each heat exchange plate 1, 1 can be returned to a state where heat exchange is performed indirectly through the heat transfer surface of each heat exchange plate 1, 1.
[0023]
In this way, after closing the water shutoff valves 6 and 7, the relief valve 20 is opened to release the volume of water that the heat exchanger body 3 has expanded due to the internal pressure of the heat exchanger body 3. Thus, it is possible to prevent the water from overflowing through the expansion tank 16 and the ozonolysis device 17, thereby avoiding the loss of the function of the expansion tank 16 and the loss of the function of the ozonolysis device 17. In addition, after performing ozone circulation cleaning by circulation of ozone-dissolved water, the operation of the ozone generation source 14 is stopped, and the dissolved residual ozone is decomposed while continuing the circulation of the ozone-dissolved water. Since ozone can be prevented from flowing down from the water supply pipe 4 to the drain pipe 5, it does not adversely affect the water supply / drain pipe system.
[0024]
【The invention's effect】
As described above, the present invention prevents the water corresponding to the volume of the heat exchanger body that has been expanded when the circulation loop is formed from overflowing through the expansion tank and the ozonolysis device, By circulating the ozone-dissolved water in a state where the loss of the function of the ozone and the function of the ozonolysis device is avoided, the microbial soil called slime is removed, and the operation of the ozone source is stopped and the ozone-dissolved water is stopped. Since the dissolved residual ozone is decomposed while continuing the circulation, the dissolved residual ozone in the circulation loop can be prevented from flowing down from the water supply pipe to the drain pipe, so that the supply / drain pipe system is not adversely affected.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an embodiment of the present invention.
FIG. 2 is a configuration diagram showing a state when an expansion component is released by opening the expansion valve.
FIG. 3 is a configuration diagram showing a formation state of a circulation loop and a water supply state to the circulation loop.
FIG. 4 is a configuration diagram showing a discharged state of cleaned sewage in the circulation loop.
FIG. 5 is a configuration diagram showing a state of supplying water to the circulation loop.
FIG. 6 is a configuration diagram of a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heat exchange plate 2 Heat exchange unit 3 Heat exchanger main body 4 Water supply pipe 5 Drain pipe 6 Water shutoff valve 7 Water shutoff valve 8 Communication pipe 9 First circulation valve 10 Check valve (second circulation valve)
DESCRIPTION OF SYMBOLS 11 Circulation loop 12 Circulation pump 14 Ozone generation source 15 Ozone supply pipe 16 Expansion tank 17 Ozone decomposer 20 Relief valve 21 Water supply tank 22 Drain valve F Heat medium W Water S Swirl

Claims (1)

A heat exchange unit composed of an assembly of a plurality of heat exchange plates is inserted into the heat exchanger body, and a heat medium is sequentially introduced and passed through each heat exchange plate from the inlet of the heat exchange unit, and heat exchange is performed from the outlet. The heat medium is led out to the outside of the unit, and water is allowed to pass inside the heat exchanger body, and the passing water and the heat medium passing through the heat exchange plates are heat transfer surfaces of the heat exchange plates. Indirect heat exchange via a water supply pipe connected to the inlet of the heat exchanger body, a drain pipe connected to the outlet of the heat exchanger body, and each of these water supply pipe and drain pipe A water shutoff valve, and a communication pipe communicating the water supply pipe on the downstream side of the water shutoff valve and the drain pipe on the upstream side of the water shutoff valve, and closing each of the water shutoff valves, And by opening the circulation valve provided in the communication pipe A circulation loop composed of the water supply pipe, the heat exchanger main body, the drain pipe and the communication pipe is formed, a circulation pump is operated, and ozone generated from an ozone generation source is supplied to the circulation loop to generate ozone. In the ozone circulation cleaning apparatus for a plate heat exchanger, in which the dissolved water is circulated and a discharge pipe in which an expansion tank and an ozone decomposer are connected in series is branched in the circulation loop, After the valve is closed, the relief valve is opened, and after the water of the volume that the body has expanded due to the internal pressure of the heat exchanger body is released, the relief valve is closed, and then the circulation valve is opened. Then, a circulation loop is formed, water is supplied from the water supply tank to the circulation loop, and then the circulation pump is operated. Then, ozone generated by the operation of the ozone generation source is supplied to the circulation loop, and ozone dissolved water is supplied. After performing ozone circulation cleaning by circulation, stop the operation of the ozone generation source, continue the circulation of the ozone dissolved water after the operation of the ozone generation source to decompose the dissolved residual ozone, and then stop the operation of the circulation pump With the water supply from the water supply tank to the circulation loop stopped, the drain valve provided in the circulation loop is opened to discharge dirty water in the circulation loop, and then the drain valve is closed to supply water. An operation control method for an ozone circulation cleaning apparatus, wherein water is supplied from a tank to a circulation loop, and then the circulation valve is closed and the water cutoff valve is opened to return to a heat exchangeable state.

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