JP4941042B2 - Water treatment equipment - Google Patents

Description

  The present invention relates to a water treatment apparatus for treating water supplied to a thermal apparatus such as a boiler.

  In this type of water treatment device, a feed water pump, a filtration membrane section that filters using a filtration membrane that captures corrosion promoting components that cause corrosion of thermal equipment, and a gas permeable membrane that permeates dissolved gas in the feed water are used. A device in which a membrane type deaeration unit for deaeration is connected in series (referred to as a water treatment unit) is known from Patent Document 1 and the like. In this water treatment device, the filtration performance of the filtration membrane portion decreases when the water flow rate decreases or the water temperature rises. On the other hand, the membrane-type deaeration unit has a characteristic that contradicts the filtration membrane unit, such that the deaeration performance is reduced due to an increase in water flow rate or a decrease in water temperature. For this reason, it is comprised so that filtration and deaeration can be performed efficiently by controlling the amount of water flow according to the change of water temperature.

JP-A-2005-279459

  In recent years, a water treatment apparatus in which a plurality of water treatment units are connected in parallel to each other has been used. In this type of water treatment apparatus, control for efficiently performing filtration and deaeration is performed. There wasn't.

  Problems to be solved by the present invention include a feed water pump, a filtration membrane section that filters using a filtration membrane that captures corrosion promoting components that cause corrosion of thermal equipment, and a gas permeable membrane that permeates dissolved gas in the feed water. It is to efficiently perform filtration and deaeration in a water treatment apparatus in which a plurality of water treatment units connected in series with a membrane type deaeration unit that is used for deaeration are connected in parallel.

The present invention has been made to solve the above-mentioned problems. The invention according to claim 1 is directed to a flow rate adjusting means capable of selecting stop, low flow rate operation and high flow rate operation, and corrosion of thermal equipment. Filters the membrane using a nanofiltration membrane that captures chloride ions and sulfate ions as corrosion-promoting components , and allows silica as a corrosion-inhibiting component to pass through, and permeates dissolved gas in the feed water A water treatment apparatus in which a plurality of water treatment units connected in series with a membrane type deaeration unit for deaeration using a gas permeable membrane are connected in parallel to each other, and the flow rate adjusting means of each water treatment unit is stopped and reduced. Control means for stopping each water treatment unit, half-load operation, full-load operation, and a water temperature sensor for detecting the temperature of the water supply or the treated water by setting the flow rate operation and the high flow rate operation, Multiple control means A first control state in which the flow rate adjusting means of the water treatment unit is operated at a low flow rate, and a second control state in which one of the flow rate adjusting means is set to a high flow rate operation and the other is stopped instead of the low flow rate operation. The first control state is set when the detected water temperature of the water temperature sensor is lower than a set value, and the second control state is set when the detected water temperature of the water temperature sensor is equal to or higher than a set value . .

  The invention according to claim 2 is characterized in that, in claim 1, the flow rate adjusting means is a water supply pump.

According to this invention, when the water temperature is low, as the first control state, the amount of water passing through each of the membrane filtration units and each of the membrane type deaeration units is reduced, and the deaeration is performed without significantly reducing the filtration performance. When the performance is improved and the water temperature is high, as the second control state, the amount of water passing through the filtration membrane can be increased, and the filtration performance can be improved without significantly reducing the deaeration performance .

  The embodiment of the present invention includes a flow rate adjusting means capable of selecting stop, low flow rate operation and high flow rate operation, a filtration membrane part that filters using a filtration membrane that captures corrosion promoting components that cause corrosion of thermal equipment, A water treatment device in which a plurality of water treatment units connected in series with a membrane-type deaeration unit that deaerates using a gas permeable membrane that permeates the dissolved gas in the feed water are connected in parallel to each other, each of the water treatment units The flow control means is stopped, low flow operation, and high flow operation so that each water treatment unit is stopped, half load operation, full load operation, and the control means includes a plurality of the water treatment units. A first control state in which the flow rate adjusting means in the processing unit is operated at a low flow rate, and a second control state in which one of the flow rate adjusting means is operated at a high flow rate and the other is stopped instead of the low flow rate operation. It is characterized by that.

  In this embodiment, when it is necessary to improve the deaeration performance such as when the water temperature is low, the control means is set to the first control state. Then, the flow rate adjusting means of the plurality of water treatment units is operated at a low flow rate, an operation with high deaeration performance is performed, and treated water with a low dissolved oxygen concentration is supplied. Further, when it is necessary to improve the filtration performance such as when the water temperature is high, the control means is set to the second control state. Then, instead of the low flow operation of the plurality of water treatment units, the flow adjustment means of one of the water treatment units is operated at a high flow rate, the flow adjustment means of the other water treatment unit is stopped, and the filtration performance is high. Operation is performed and treated water with a low concentration of corrosion promoting components is supplied.

  Here, the components of this embodiment will be described. The filtration membrane part has a function of filtering using a filtration membrane that captures corrosion promoting components. As this filtration membrane, preferably, a nanofiltration membrane that captures corrosion promoting components such as chloride ions and sulfate ions contained in the feed water and permeates silica recognized as a corrosion inhibiting component is used. This filtration membrane part has the characteristic that filtration performance will fall, if an effective pressure falls, such as to-be-processed water flow volume falls or water temperature rises.

  The nanofiltration membrane is a polyamide or polyether synthetic polymer membrane. Further, the nanofiltration membrane is a liquid separation membrane that can prevent permeation of particles and polymers (having a maximum molecular weight of about several hundreds) smaller than about 2 nm. In addition, the nanofiltration membrane has an ultrafiltration membrane (a membrane capable of filtering out one having a molecular weight of about 1,000 to 300,000) and a reverse osmosis membrane (a molecular weight of about several dozen) in terms of its filtration function. It is a liquid separation membrane having a function located in the middle of a membrane that can be filtered off. Incidentally, the nanofiltration membrane is commercially available and can be easily obtained.

The flow rate adjusting means is preferably a feed water pump that can be selected from stop, low flow rate operation, and high flow rate operation by rotation speed control such as inverter control, etc., but the feed water pump and the flow rate adjustment valve are connected in series, etc. By combining them, it is possible to configure such that stop, low flow operation and high flow operation can be selected. The low flow rate operation is preferably 50% of the high flow rate operation, but is not limited to this and can be set between 60% and 70%.

  The membrane-type deaeration unit degass using a gas permeable membrane that allows the dissolved gas in the feed water to pass through. This membrane-type deaeration part is formed by forming a gas permeable membrane into a tubular, hollow fiber-like, pleated, spiral-like (spirally wound) shape, etc., and in this state accommodated in a suitable container, one component It is used as a so-called membrane module. This deaeration device has a characteristic that the deaeration performance decreases when the amount of water to be treated increases or the water temperature decreases.

  The inside of the membrane module is divided into a liquid phase side and a gas phase side, and on the liquid phase side, water to be treated (also referred to as raw water, well water, tap water, various industries) A treated water supply line having a feed water pump for supplying water (including water, other liquid products, etc.) and a treated water supply line for supplying a treated water tank for storing treated water after deaeration treatment are connected .

  On the gas phase side, a vacuum suction line is connected to a decompression means for vacuum suction in the compartment. Then, in the process of circulating the water to be treated in the membrane module, by vacuum suction through the gas permeable membrane, the dissolved gas in the water to be treated is sucked and removed, and the degassed treated water is removed from the treated water supply line. It is configured to supply to the treated water tank. The decompression means is preferably a water ring vacuum pump.

  The number of water treatment units is not limited to 2 and can be 3 or more. In addition, each flow rate adjusting means can be configured to control not only three steps of stop, low flow rate, and high flow rate but also four or more steps.

  The control unit is configured to stop the flow rate of each flow rate adjusting unit according to the water level of the treated water tank, to perform a low flow rate operation, and a high flow rate operation according to a water treatment program stored in advance. A unit is selectively controlled to stop, half load operation, and full load operation, and a plurality of the water treatment unit flow control means are in a low flow operation, and a plurality of the flow control means are low flow rates. Instead of the operation, one is configured to select a second control state in which one is operated at a high flow rate and the other is stopped. The first control state and the second control state are preferably selected according to the water temperature, but are not limited thereto. When controlling according to the water temperature, the first control state is set when the water temperature is lower than the set value, and the second control state is set when the water temperature is equal to or higher than the set value.

  Hereinafter, Example 1 of the water treatment equipment concerning this invention is described based on Drawings 1-4. FIG. 1 is a schematic explanatory diagram of the first embodiment, FIGS. 2 and 3 are diagrams for explaining different operation patterns, and FIG. 4 is an explanatory diagram of a water treatment program of the first embodiment.

  The water treatment apparatus according to the first embodiment supplies water such as tap water, industrial water, and groundwater supplied from an external water source (not shown) to thermal equipment such as a steam boiler, a hot water boiler, a cooling tower, and a water heater. It is constructed on the water supply line 1.

In the first water supply line 1 a branched from the water supply line 1, a first filtration membrane portion that performs filtration using a first water supply pump 2 a as a flow rate adjusting means and a filtration membrane that captures a corrosion promoting component that causes corrosion of the thermal equipment. 3a and the first membrane type deaeration unit 4a are connected in series to form a first water treatment unit 5a. The second water supply line 1b branched from the water supply line 1 is connected in series with a second water supply pump 2b as a flow rate adjusting means, a second filtration membrane portion 3b, and a second membrane deaeration portion 4b. Thus, the second water treatment unit 5b is formed. The water treatment units 5 a and 5 b are connected in parallel to each other and connected to the treated water rank 7 via the treated water line 6.

  The nanofiltration membrane is used as the filtration membrane of the filtration membrane portion 2. Each of the feed water pumps 2a and 2b is configured to be able to select a low flow operation, a high flow operation, and a stop by inverter control. The water treatment units 5a and 5b are set to a half load operation and a full load operation according to the low flow operation and the high flow operation of the water supply pumps 2a and 2b. The high flow rates of the pumps 2a and 2b are controlled by an inverter so as to supply a constant amount of water required for the effective pressure of the filtration membranes of the filtration membrane portions 3a and 3b when the water temperature is equal to or higher than a set value. The low flow rates of the pumps 2a and 2b are such that when the water temperature is equal to or lower than a set value, the dissolved gas concentration after deaeration of the dissolved gas in the feed water does not exceed a predetermined dissolved gas residual allowable value. The inverter is controlled so that a certain degree of deaeration can be performed.

  Moreover, the water temperature sensor 8 which measures the temperature of water supply is provided in the water supply line 1 of the arbitrary positions of the water supply line 1, and the upstream water supply line 1 of each said water treatment unit 4a, 4b in the present Example 1. FIG.

  In the first embodiment, an activated carbon filtration unit that adsorbs and removes an oxidizing agent such as sodium hypochlorite dissolved in the feed water from the raw water side on the feed water line 1 upstream of the pumps 2a and 2b. 9 to prevent clogging of the filtration membranes of the filtration membrane portions 2a and 2b due to dust and the like, and the soft water treatment portion 10 that removes hardness components such as calcium and magnesium contained in the water supply with ion exchange resin The filter 11 is arranged. Moreover, the 1st, 2nd concentrated water drainage lines 12a and 12b which drain the concentrated water produced | generated by filtration are connected to each said filtration membrane part 3a, 3b.

  Each of the water supply pumps 2a and 2b is controlled based on a water treatment program stored in advance by a controller 14 that receives detection signals of the water temperature sensor 8 and the water level sensor 13 for detecting the water level of the treated water tank 7. As shown in FIG. 4, when the water temperature is lower than a set value, the water treatment program causes the water supply pumps 2 a and 2 b of the water treatment units 5 a and 5 b to operate at a low flow rate when the water temperature is lower than a set value. A first control pattern including a first control state to be performed, and a second control state in which, when the water temperature is equal to or higher than a set value, one of the water supply pumps 2a and 2b is operated at a high flow rate instead of a low flow rate operation, and the other is stopped. The second control pattern including can be selected. The first control pattern is shown in FIG. 2, and the second control pattern is shown in FIG.

  Operation | movement of the water treatment apparatus of the present Example 1 comprised as mentioned above is demonstrated. Referring to FIG. 4, in S1, it is determined whether the detected value of the water temperature sensor 8 is less than a set value. If YES is determined here, the process proceeds to S2, and the controller 14 executes the first control pattern shown in FIG. That is, when the water level of the treated water tank 7 is equal to or lower than the first set water level L1, the feed water pumps 2a, 2b of the first water treatment unit 5a and the second water treatment unit 5b are controlled to high flow operation, To full load operation (total full load operation). When the water level exceeds the first set water level L1, the feed water pump 2b of the second water treatment unit 5b is set to a low flow operation and a half load operation (total 3/4 load operation).

  Further, when the water level exceeds the second set water level L2, both the feed water pumps 2a and 2b of the first water treatment unit 5a and the second water treatment unit 5b are controlled to low flow operation, and both are operated at half load. (Total half-load operation). This total half-load operation is in the first control state, and the deaeration performance can be improved by halving the flow rate for each of the membrane deaeration units 4a and 4b. The operation in the first control state is a deaeration performance priority operation. When the water level exceeds the third set water level H, the water supply pumps 2a and 2b are stopped (total stop operation).

  When the water temperature is high and NO is determined in S1, the process proceeds to S3, and the controller 14 executes the second control pattern shown in FIG. The second control pattern differs from the first control pattern only in the water level between the second water level L2 and the third water level H. That is, in the second control pattern, when the water level exceeds the second water level L2, the first water treatment unit 5a is operated at full load and the second water treatment unit 5b is stopped in the second control state. (Total half-load operation). This total half-load operation is in the second control state, and the filtration performance can be improved by setting the flow rate to a high flow rate for the membrane filtration unit 3a. The operation in the second control state is a filtration performance priority operation.

  According to the first embodiment, when the water temperature is low, the operation is performed in the first control state, thereby giving priority to the deaeration performance. When the water temperature is high, the operation is performed in the second control state. Since the filtering performance can be controlled with priority, appropriate water treatment can be performed in response to changes in the water temperature.

  Moreover, in this Example 1, by making the several water treatment unit 5a, 5b into the same load state, by including the operation state which combined the thing of a full load operation and the thing of a half load operation, it is more Fine water treatment can be realized.

It is a schematic explanatory drawing which shows Example 1 of the water treatment apparatus which concerns on this invention. It is explanatory drawing of the control pattern of the Example. It is explanatory drawing of the other control pattern of the Example. It is a flowchart figure explaining the principal part control procedure of the Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Water supply line 1a 1st water supply line 1b 2nd water supply line 2a 1st water supply pump (flow rate adjustment means)
2b Second water supply pump (flow rate adjusting means)
3a First membrane filtration unit 3b Second membrane filtration unit 4a First membrane warm deaeration unit 4b Second membrane deaeration unit 5a First water treatment unit 5b Second water treatment unit 14 Controller

Claims (2)

Flow control means that can be selected between stop, low flow operation and high flow operation, and nanofiltration that captures chloride and sulfate ions as corrosion-promoting components that cause corrosion of thermal equipment and permeates silica as a corrosion-inhibiting component A plurality of water treatment units in which a filtration membrane part that filters using a membrane membrane and a membrane type deaeration part that degass using a gas permeable membrane that permeates dissolved gas in the feed water are connected in series. A water treatment device connected to
Control means for stopping the water treatment units, half-load operation, full-load operation by stopping the flow rate adjusting means of each water treatment unit, low-flow operation, high-flow operation ,
A water temperature sensor for detecting the temperature of the water supply or the treated water ,
The control means is a first control state in which the plurality of water treatment unit flow rate adjusting means are operated at a low flow rate, and one of the flow rate adjusting means is set to a high flow rate operation instead of the low flow rate operation, and the other is stopped. The second control state is selectable, and when the detected water temperature of the water temperature sensor is lower than a set value, the first control state is set.When the detected water temperature of the water temperature sensor is equal to or higher than the set value, the second control state is set. A water treatment apparatus characterized by that.   The water treatment apparatus according to claim 1, wherein the flow rate adjusting means is a water supply pump.