JP2019166473A - Pure water production apparatus - Google Patents

Abstract

To provide a pure water production apparatus capable of stably producing pure water having high water quality.SOLUTION: A part of fresh water in a fresh water tank 1 is used as supply water of a low pressure boiler or a middle pressure boiler. The fresh water in the fresh water tank 1 is supplied through a pipe 2, a valve 3, a water supply pump 4 and an MF membrane device 5 constituting a main system 10 to an RO device 6. Permeable water of the RO device 6 is supplied to an electric deionization device 11. A preliminary system 20 passes the fresh water from the fresh water tank 1 to an MF membrane device 25 with a pipe 21, a valve 22 and a water supply pump 24, and passes MF filtrate water to an ion exchange resin device 26 and deionizes the MF filtrate water to produce pure water. A slime control agent substantially containing no hardness component and halogen substance can be added to any one of treated water, RO supply water and RO concentration water.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pure water production apparatus, and more particularly to a pure water production apparatus suitable for a pure water production apparatus in a ship.

  In ships that sail in the ocean, it is important to secure water such as drinking water and domestic water. Therefore, a ship is often equipped with a fresh water generator that produces fresh water from seawater by distillation or the like. Moreover, the fresh water manufactured with the fresh water generator may be used as boiler water supply other than drinking water etc. (patent document 1).

Here, the boiler in a ship is used for the following uses, for example.
(1) In the turbine ship, a main boiler is installed as a steam generator for supplying superheated steam to the turbine.
(2) Diesel ships require a large amount of steam for heating, cooking, hot water supply, heating, etc. for fuel, lubricating oil, cooling fresh water, and install an auxiliary boiler that supplies saturated steam to supplement the diesel engine .
(3) In a tanker ship, a boiler for supplying boiler exhaust (non-combustible) with an oxygen concentration ≦ 5% is installed as an inert gas for pushing out the volatile gas in the cargo tank.

Conventionally, low-pressure / medium-pressure boilers are mainly used as inboard boilers in any application. In this case, when fresh water is used as boiler feed water, the case where the quality of fresh water leads to poor operation is difficult to be realized.
Here, in particular, a turbine ship needs to manufacture steam for operating a steam turbine mainly by a boiler, and the influence of the number of operating boilers on fuel efficiency is great. Therefore, in recent years, an approach for reducing fuel consumption by reducing the number of operating boilers by using a high-pressure boiler as a boiler and operating a plurality of steam turbines with one high-pressure boiler has been studied.

  However, when a high-pressure boiler is used as an inboard boiler, since the boiler feed water is hot, poor water quality (for example, corrosiveness) tends to lead to poor operation of the boiler. Because the impact when a boiler becomes inoperable is enormous, it is possible to further improve the quality of boiler feedwater from fresh water, desalinate to produce so-called pure water, and use pure water as boiler feedwater It is considered desirable.

  As a pure water production apparatus for boilers, a device in which a UF membrane device, an RO device, and electric membrane ions are installed in series is known (Patent Document 2).

JP 2007-132227 A Japanese Patent Laid-Open No. 2003-136065

  If the water flow to the RO device is continued, slime adheres to the RO membrane and the filtration performance deteriorates. In normal cases, there is no RO equipment chemical cleaning equipment installed in the ship, so even if the RO equipment deteriorates due to slime adhesion during navigation, the RO equipment cannot be cleaned and the RO equipment performance is restored. I can't let you.

  An object of this invention is to provide the pure water manufacturing apparatus which can manufacture the pure water of high water quality stably.

  The pure water production apparatus of the present invention is a pure water production apparatus for producing pure water by treating the treated water with at least an RO apparatus. The treated water, the water supplied to the RO apparatus, and the concentrated water of the RO apparatus. At least one is provided with an adding means for adding a slime control agent substantially free of a hardness component and a halogen substance.

  The pure water production apparatus of one aspect of the present invention is a pure water production system capable of producing pure water by treating water to be treated with at least the RO device, and capable of passing water in series or in parallel with the main series. And a preliminary sequence for use.

  The pure water manufacturing apparatus according to one embodiment of the present invention is for ship use.

  In one aspect of the present invention, the preliminary series includes an ion exchange resin device.

  In 1 aspect of this invention, it has the electrodeionization apparatus which processes the permeated water of the said RO apparatus.

  The pure water production apparatus of the present invention has means for adding a slime control agent substantially free of hardness components and halogen substances to at least one of treated water, RO feed water, and RO concentrated water.

  In order to prevent biofouling due to slime adhesion to the RO membrane, if a chlorine-based disinfectant is used as a slime control agent, the ion-exchange resin in the electric desalination apparatus or ion-exchange resin tower is likely to deteriorate, and the RO Corrosion is likely to occur in low and medium pressure boilers where fresh water circulated from the concentrated water to the tank and mixed is supplied. Further, when an agent mixed with a hardness component is used as a slime control agent, scale is likely to occur in a boiler heat exchanger or the like. In contrast, by using a slime control agent that does not substantially contain a hardness component and a halogen substance as a slime control agent as in the present invention, it prevents (inhibits) slime adhesion on the RO membrane while preventing the occurrence of the above trouble. Can be included).

  The pure water production apparatus according to one aspect of the present invention includes a preliminary series, so that when the performance of the main series deteriorates or the main series malfunctions, the preliminary series is immediately activated to produce pure water with good water quality. Can continue.

  A ship equipped with the pure water production apparatus of the present invention can be used to the next port of call without repairing the failure of the main line even when the performance of the main line deteriorates or the main line of the pure water production apparatus fails. You can sail.

It is a block diagram of the pure water manufacturing apparatus which concerns on embodiment. It is a block diagram of the pure water manufacturing apparatus which concerns on embodiment.

  FIG. 1 shows a pure water production apparatus according to an embodiment. Fresh water obtained by distilling seawater is introduced into the fresh water tank 1. A part of the fresh water in the fresh water tank 1 is used as water supply for a low pressure boiler or an intermediate pressure boiler. Fresh water in the fresh water tank 1 is supplied to an RO (reverse osmosis) device 6 through a pipe 2, a valve 3, a feed water pump 4, and an MF membrane device 5 constituting the main series 10. The concentrated water of the RO device 6 is returned to the fresh water tank 1 through the pipe 7, and a part thereof is discharged out of the system through the blow pipe 8 and the blow valve 9 branched from the pipe 7.

  The permeated water of the RO device 6 is supplied to the electrodeionization device 11. As in Patent Document 2, the electrodeionization apparatus 11 includes a cathode and an anode, a plurality of cation exchange membranes and anion exchange membranes arranged between the cathode and anode, and a concentration formed between these membranes. A chamber, a desalting chamber, an ion exchanger filled in the desalting chamber, and a power supply device for applying a voltage between the anode and the cathode. The RO permeated water is deionized while passing through the desalting chamber to become pure water. Part of this pure water is taken out via the pipe 12 and the valve 13 and used as water supply for a high-pressure boiler or the like. The remaining pure water is returned to the fresh water tank 1 via the pipe 15.

Hardness components and halogen substances are substantially reduced by the slime control agent adding device 18 (comprising a chemical tank and a chemical injection pump) with respect to the RO concentrated water returned from the RO device 6 to the fresh water tank 1 through the pipe 7. The slime control agent which does not contain can be added. By adding this slime control agent, the slime failure of the fresh water tank 1 to which the RO concentrated water is returned is prevented, and further, the fresh water diffused in the fresh water tank 1 is supplied as the RO feed water. Is prevented. Further, as described above, deterioration of the electrodeionization apparatus 11 and ion exchange resin described later is prevented. In addition, by using a slime control agent that does not substantially contain a hardness component and a halogen substance as a slime control agent, scale generation in a boiler heat exchanger or the like is also prevented.
In the present invention, a slum control agent may be added to any of RO water supply, RO concentrated water, and fresh water, but when added to RO water supply, the RO water supply is a high-pressure line and requires a high-pressure pump. If added to a high concentration, there is a concern about deterioration of the RO membrane and the ion exchange resin of the electrodeionization apparatus 11. Further, when added to the fresh water tank 1, it is considered that it takes time to achieve sufficient uniform mixing in the tank. Therefore, it is preferable to add a slime control agent to the RO concentrated water so that the chemical can be easily added and can be easily mixed in a fresh water tank. However, it is desirable to add it to the fresh water tank when operating only the backup line.

  The slime control agent needs to be an agent that does not substantially contain halogen substances such as chlorine and bromine and hardness components (Ca, Mg). However, even if the agent does not contain chlorine or bromine, it is common to contain a trace amount of hardness component, and it is not enough to use demineralized water as the preparation water, so using hydrazine causes trouble. It is preferable to perform slime control of the RO membrane while preventing it. It is preferable to prepare and use a chemical solution in which hydrazine is adjusted to a predetermined concentration with demineralized water.

  Another embodiment will be described with reference to FIG. In this embodiment, the pure water production apparatus shown in FIG. 1 is provided as the main series 10, and a spare series 20 is further provided separately from this.

  In the preliminary series 20, fresh water from the fresh water tank 1 is passed through the MF membrane device 25 by the pipe 21, the valve 22, the pipe 23, and the water supply pump 24, and the MF filtered water is passed through the ion exchange resin device 26 for deionization. It is configured to produce pure water by processing. The pure water from the preliminary series 20 flows from the pipe 27 in the order of the pipe 12 to the fresh water tank 1 through the pipe 15, and a part thereof is taken out through the valve 13 during use.

  The quality of pure water (such as specific resistance or electrical conductivity) from the electrodeionization device 11 is measured by a sensor such as a resistivity meter or an electric conductivity meter, and the flow rate of pure water from the electrodeionization device 11 is a flow rate. Measurement is performed by sensors, and detection signals from these sensors are input to a controller (not shown). The controller monitors the quality and quantity of pure water during the operation of the main series 10 described above, and at least one of the quality and quantity of water falls below a set value for a predetermined period or longer (poor water quality or water quantity is low). In the case of a small number), it is determined that some abnormality has occurred in the main series 10, and the management department of the pure water production apparatus is notified of the abnormality using a satellite communication system or the like, and the pure water production by the preliminary series 20 is performed. Let it begin.

  When operating the standby system 20, the main system 10 may be stopped, and the entire amount of pure water produced by the pure water production apparatus may be manufactured by the standby system 20, and both the main system 10 and the standby system 20 are operated, The pure water from the main line 10 and the pure water from the backup line 20 may be merged and taken out.

  In FIG. 2 described above, the main series 10 and the standby series 20 are installed in parallel, but a series connection pipe 30 indicated by a two-dot chain line in FIG. 2 may be provided. The amount of pure water from the electrodeionization device 11 is sufficient, but if the water quality is poor, the pure water from the electrodeionization device 11 is passed through the preliminary series 20 with the valve 22 closed. After processing, pure water with good water quality is flowed in the order of the pipes 27 and 12, returned to the fresh water tank 1 through the pipe 15, and a part is taken out through the valve 13 during use.

  As described above, since the standby series 20 capable of passing water in parallel or in series with the main series 10 is installed, pure water can be stably produced even if a trouble occurs in the main series 10. In addition, since pure water is stably supplied to the high-pressure boiler, the ship can be navigated to the next port of call.

  In the above embodiment, the pipe 21 for supplying the fresh water in the fresh water tank 1 to the standby system 20 is directly connected to the fresh water tank 1, but the pipe 21 may be branched from the pipe 2.

  In the above embodiment, the MF membrane device 5 is used, but a UF membrane device may be used. Also, these membrane devices may be omitted. 1 and 2, only one stage of the RO device 6 is shown, but it may be installed in two or more stages.

  The ion exchange resin device 26 has features such as space saving; fast start-up; withstands fluctuations in raw water quality; and maintenance work is simple or unnecessary. The ion exchange resin apparatus has a shorter life until breakthrough compared to an electrodeionization apparatus or the like, but it is only necessary to stably demineralize for a short period until the next port of call. Can be used. In particular, in order to save space by simplifying the apparatus, it is preferable to use a non-regenerative ion exchange resin apparatus.

  As an ion exchange resin apparatus, only one tower or two towers may be arranged in series. In the case of two towers, various combinations such as cation exchange → anion exchange, anion exchange → cation exchange, anion / cation mixture → anion / cation mixture can be employed. In addition, the tower is filled with cationic resin and anion resin in a layered state, and the tower is divided into upper and lower chambers by horizontal water shielding plates, and piping is provided for draining from the upper chamber and introducing it into the lower chamber. A two-stage treatment of cation exchange / anion exchange may be performed in one tower such as a system.

  Furthermore, when more stable treatment is required, it is preferable to perform membrane filtration treatment with an MF membrane, UF membrane, or the like in the preliminary series as shown in FIG.

  Thus, by installing the preliminary sequence 20 having a removal mechanism different from that of the main sequence 10, there is also an advantage that troubles caused by the same cause as the main sequence can be avoided.

In the case of FIG. 2, while the main line 10 is operating normally, the preliminary line is basically not used for desalting and may be stopped in the immersed state, but the generation of bacteria is suppressed. In order to be able to collect water immediately after the switching, it is preferable to circulate water in the standby system using the pipe 28 and to stand by. However, in this case, there is concern about the rise in water temperature (above 50 ° C.) in the preliminary system and the accumulation of organic substances eluted from the ion exchange resin. It is preferable to control so that. In addition, when the return water from the pipe 28 is returned to the fresh water tank 1, it takes in water in which atmospheric CO ₂ is dissolved, and a load is applied to the ion exchange resin. Therefore, it is preferably returned to the pipe 23.

DESCRIPTION OF SYMBOLS 1 Fresh water tank 6 RO apparatus 10 Main series 11 Electrodeionization apparatus 18 Slime control agent addition apparatus 20 Preliminary series 26 Ion exchange resin apparatus

Hardness components and halogen substances are substantially reduced by the slime control agent adding device 18 (comprising a chemical tank and a chemical injection pump) with respect to the RO concentrated water returned from the RO device 6 to the fresh water tank 1 through the pipe 7. The slime control agent which does not contain can be added. By adding this slime control agent, the slime failure of the fresh water tank 1 to which the RO concentrated water is returned is prevented, and further, the fresh water diffused in the fresh water tank 1 is supplied as the RO feed water. Is prevented. Further, as described above, deterioration of the electrodeionization apparatus 11 and ion exchange resin described later is prevented. In addition, by using a slime control agent that does not substantially contain a hardness component and a halogen substance as a slime control agent, scale generation in a boiler heat exchanger or the like is also prevented.
In the present invention, it may be added to slide Lee beam control agent in any of the RO water and RO concentrate and fresh water, but when added to RO feedwater, RO water supply is required pumps for high pressure for the high pressure line Moreover, when added to a high concentration, there is a concern about deterioration of the RO membrane and the ion exchange resin of the electrodeionization apparatus 11. Further, when added to the fresh water tank 1, it is considered that it takes time to achieve sufficient uniform mixing in the tank. Therefore, it is preferable to add a slime control agent to the RO concentrated water so that the chemical can be easily added and can be easily mixed in a fresh water tank. However, it is desirable to add it to the fresh water tank when operating only the backup line.

Claims (6)

  In a pure water production apparatus for producing pure water by treating water to be treated with at least an RO device, a hardness component and a halogen substance are included in at least one of the water to be treated, water supplied to the RO device, and concentrated water of the RO device. An apparatus for producing pure water, characterized in that it comprises an adding means for adding a slime control agent that is substantially free of sucrose.   It has a main series for producing pure water by treating the water to be treated with at least the RO device, and a preliminary series for producing pure water capable of passing water in series or in parallel to the main series. The pure water manufacturing apparatus according to claim 1.   The apparatus for producing pure water according to claim 1 or 2, which is for use on a ship.   4. The pure water production apparatus according to claim 2, wherein the preliminary series includes an ion exchange resin apparatus.   The pure water production apparatus according to any one of claims 2 to 4, wherein the main series includes an electrodeionization apparatus that processes permeated water of the RO apparatus.   The pure water production apparatus according to claim 1, wherein the slime control agent is hydrazine.

Images