JP6651866B2 - Dissolution / dilution equipment for polymer liquid - Google Patents

Description

  The present invention relates to an apparatus for dissolving or diluting a liquid polymer or a polymer liquid such as a polymer solution or dispersion in a medium such as water.

  Liquid polymer coagulants such as emulsion-type polymers and dispersion-type polymers are 2 to 5 times more effective when the stock solution is dissolved in water to about 0.1 to 1% than when used as the stock solution. Therefore, it is desirable to use it after dilution. In a conventional automatic dilution, dissolution, and injection device, water and polymer are continuously or intermittently placed in a stirring tank for dilution and dissolution, sufficiently stirred and dissolved in the tank, and then the solution is pumped and injected. Or the stock polymer was injected into the water sent by piping, and then stirred and dissolved by a line mixer before injection.

  Line mixers are prone to clogging, require frequent cleaning, and do not have long residence times, making it difficult to adequately dissolve the polymer. In addition, in the method of stirring and dissolving in a tank, the solution to be sent by the pump is a polymer solution and the viscosity is high, the pump is also somewhat special, and the stirrer, control and other equipment are complicated and expensive. .

  Patent Literature 1 describes a dissolving method and a dissolving system in which a polymer chemical liquid is added by a pump while diluting water is supplied through a pipe by a fixed amount supply device, and then mixed by a line mixer or a centrifugal pump. A mixing device such as a line mixer or a centrifugal pump is required.

  Patent Document 2 discloses that dilution water is added to an emulsion polymer or a primary diluent thereof and mixed with a static mixer, but a static mixer is required.

JP-A-10-57790 JP 2007-69167

  Using a mixing device such as a static mixer, a line mixer, or a centrifugal pump complicates the structure of the dissolving / diluting device and increases the cost. May be impaired.

  The present invention does not require a mixing device such as a static mixer, a line mixer, a centrifugal pump, and the like, and provides a polymer liquid dissolving / diluting device that has a simple device configuration and excellent operation stability. Aim.

  The polymer liquid dissolving / diluting apparatus of the present invention includes: a pipe through which water for dissolving or diluting is supplied to a polymer injection point of the water system to be treated via a first diaphragm pump and a first check valve; And a polymer liquid supply means for supplying a polymer liquid into the pipe via a second check valve downstream of the one check valve.

  In the present invention, it is preferable that the polymer liquid supply means has a second diaphragm pump for feeding the polymer liquid.

  In the present invention, it is preferable that the length of the pipe from the polymer liquid supply point to the injection point into the water to be treated has a residence time of the supplied liquid of 1 minute or more.

  In the polymer liquid dissolving / diluting device of the present invention, water supplied from the first diaphragm pump flows in a pipe (hose) while pulsating, and the polymer liquid is added to the pipe. The polymer liquid is sufficiently uniformly dissolved and / or diluted by the stirring effect of the water flowing in the pipe while pulsating.

  By adding the polymer liquid with the second diaphragm pump, the polymer liquid is also added while pulsating, and the polymer liquid is dissolved or diluted sufficiently uniformly.

  The polymer liquid dissolving / diluting device of the present invention does not have a mixing device such as a line mixer and is low in cost. In addition, there is no trouble due to blockage of the mixing device and the like, so that the operation is performed stably.

1 is a configuration diagram of a polymer liquid dissolving / diluting device according to an embodiment.

  Hereinafter, an apparatus for dissolving and diluting a polymer liquid according to an embodiment will be described with reference to FIG.

  Working water is introduced into a tank 1 for storing water for dissolution and dilution (in this embodiment, working water (industrial water)) by a ball tap 1a so as to reach a specified water level. The water in the tank 1 is sent through a hose 2a, a diaphragm pump 2, a hose 2b, and a first check valve (butterfly check valve in this embodiment) 3 to a hose 4 as a pipe made of a blade hose or the like. It is. The end of the hose 4 is connected to the first inlet 5 a of the cheese 5.

  The polymer liquid in the polymer liquid tank 6 is supplied to the second inflow port 5b of the cheese 5 via a diaphragm 8 and a hose 8 as a pipe including a hose and a check valve 9. A hose 10 as a pipe made of a long hose or the like is connected to the outlet 5c of the cheese 5, and a dissolved or diluted liquid is injected from the end of the hose 10 into water to be treated such as booth circulating water or drainage.

  The working water from the tank 1 is sent to the hose 10 by the diaphragm pump 2 and thus pulsates. Further, the polymer liquid from the polymer liquid tank 6 is also pulsated because it is sent from the cheese 5 to the hose 10 by the diaphragm pump 7. Thus, the polymer liquid is sufficiently dissolved or diluted by the stirring effect obtained by flowing the working water and the polymer liquid in the pipe 10 while pulsating.

  Preferably, the length L of the hose 10 is such that a residence time is required to sufficiently dissolve the polymer. The residence time for sufficiently dissolving the polymer varies depending on the polymer solution, but it is preferable that the residence time be 1 minute or more for any of the polymer solutions, and 2 minutes or more for the dispersion polymer and the emulsion polymer. In this case, the time is more preferably 3 minutes or more.

  In order to sufficiently dissolve or dilute the polymer liquid, it is preferable that the dissolving or diluting liquid be supplied in the hose 10 at a sufficient flow rate. %, The inner diameter of the hose 10 is 4 to 50 mm, and the flow rate of the polymer diluent (polymer solution + water for dissolution or dilution) is about 10 to 100,000 mL / min, particularly 500 to 50,000 mL. / Min is preferable.

  The dissolving / diluting device for the polymer liquid does not require a mixing device such as a line mixer, a static mixer, and a centrifugal pump, and has a simple configuration and low cost. Further, since the mixing device is not used, there is no blockage in the mixing device, and the operation stability of the device is excellent. By increasing the length of the pipe 10, even a polymer liquid that is difficult to dissolve can be sufficiently dissolved or diluted. The length of the hose 10 may be adjusted according to the dissolution characteristics of the polymer liquid.

  Examples of the polymer liquid to be dissolved or diluted in the present invention include a liquid polymer (undiluted solution) and a solution or dispersion thereof. As the polymer liquid, specifically, a liquid polymer flocculant is suitable, and a liquid polymer flocculant such as an emulsion polymer or a dispersion polymer is exemplified.

  By determining the flow rate of the working water from the pump 2 and the flow rate of the polymer liquid from the pump 7, it is possible to supply the polymer liquid dissolved water or the dispersion liquid having a specified concentration.

  In addition, the water for dissolving or diluting is arbitrary such as tap water and groundwater in addition to industrial water.

[Example 1]
An aqueous polymer solution to be added to the sludge collecting device in the circulating water pit of the coating booth was produced using the device shown in FIG.

  The ball tap 1a was attached to the tank 1 consisting of a 30L polypropylene tank. The water tap and the ball tap 1a were connected with a 15 mm inner diameter blade hose. A Takumina CS2 diaphragm pump (1.5 L / min, 0.3 MPa) 2 is installed on the tank 1, one end of the hose 2 a is connected to the suction port of the pump 2, and the other end of the hose 2 a is inserted into the tank 1. I inserted.

  The discharge port of the pump 2 was connected to the inlet of a brass butterfly check valve 3 via a hose 2b having a length of 1 m. The outlet of the butterfly check valve 3 was connected to the inlet 5a of the cheese 5 via a hose 4 having a length of 20 cm. A check valve (CA4) 9 for polymer stock solution was attached to the inflow port 5b of the cheese 5, and the rear end of the hose 10 having an inner diameter d = 15 mm and a length L = 20 m was connected to the outflow port 5c. This hose 10 was wound and placed compactly in one place.

  A check valve 9 for the polymer stock solution was connected to a discharge port of a diaphragm pump (solenoid type, 38 ml / min, 1 MPa) 7 manufactured by Iwaki Corporation via a hose 8 (50 cm in length) having an inner diameter of 4 mm. The tip of a hose 7a connected to the suction port of the diaphragm pump 7 is inserted into a polymer stock solution (Crystack B-303 manufactured by Kurita Kogyo Co., Ltd., a polymer flocculant composed of a dispersion type cationic polymer) in a polymer solution tank 6. It is.

  The end of the hose 10 was set so that the dissolved polymer flowing out of the hose 10 was sucked into the suction port of a floating sludge intake pump (submersible pump) in the booth circulation water pit.

  The diaphragm pump 2 is actuated to pump the working water in the tank 1 to the hose 10 at 1.5 L / min (residence time in the hose 2.3 minutes, linear velocity 8.7 m / min), and the diaphragm pump 7 It was operated and the stock polymer solution was injected into the hose 10 through the cheese 5 at 10 mL / min.

The flocculated water sent from the floating sludge intake pump was sent to a pressurized floating device (water intake 100 L / min, capacity 3 m ³ ), and the aggregated sludge floated and was scraped off. The treated water from which the floating sludge was separated was returned to the pit. The treated water and the coagulated liquid entering the pressure flotation device (raw water in Table 1; hereinafter the same) were collected, and the concentration of each suspended solid was measured by the JIS method. Table 1 shows the results.

[Example 2]
A test was performed in the same manner as in Example 1 except that the polymer flocculant was changed to Crifix EC-482 (Emulsion type cationic polymer, Kurita Water Industries Ltd.), and the added amount was 5 mL / min. The treated water and the flocculated liquid entering the pressure flotation device were collected, and the concentration of each suspended substance was measured by the JIS method. Table 1 shows the results.

[Example 3]
The test was performed in the same manner as in Example 2 except that the length of the hose 10 for feeding the polymer mixture was 30 m. The treated water and the flocculated liquid entering the pressure flotation device were collected, and the concentration of each suspended substance was measured by the JIS method. Table 1 shows the results.

[Comparative Example 1]
The same test as in Example 1 was performed except that the polymer stock solution was directly added to an intake port (a suction port of a floating sludge intake pump in the booth circulating water pit). The treated water and the flocculated liquid entering the pressure flotation device were collected, and the concentration of each suspended substance was measured by the JIS method. Table 1 shows the results.

[Comparative Example 2]
The same test as in Example 3 was performed except that the polymer was added to the water intake as the undiluted solution. The treated water and the flocculated liquid entering the pressure flotation device were collected, and the concentration of each suspended substance was measured by the JIS method. Table 1 shows the results.

[Comparative Example 3]
A check valve and a valve were attached to the discharge port of the working water in the factory where the pressure was applied (about 0.5 MPa) without using the diaphragm pump 2, and the working water was supplied at 1.5 L / min from here. Except for this, the diluted polymer was sent to the suction port of the water pump in the same manner as in Example 1. In this case, since no diaphragm pump is used, there is no pulsation in the pumped water. The treated water and the flocculated liquid entering the pressure flotation device were collected, and the concentration of each suspended substance was measured by the JIS method. Table 1 shows the results.

  As shown in Table 1, according to Examples 1 to 3, the suspended solids concentration of the treated water was found to be significantly lower than that of the comparative example. In particular, according to Example 3 in which the length of the hose 10 was 30 m, It was found to be more effective than Example 2.

1,6 tank 2,7 diaphragm pump 5 cheese 10 piping (hose)

Claims (3)

A pipe through which water for dissolution or dilution is supplied to an injection point into the water system to be treated via a first diaphragm pump and a first check valve;
And a polymer liquid supply means for supplying a polymer liquid as a liquid polymer flocculant into the pipe via a second check valve downstream of the first check valve. Dissolving and diluting device for polymer liquid. According to claim 1, wherein the polymer solution supply means, dissolution and dilution device of a polymer solution characterized by having a second diaphragm pump for feeding the polymer solution. According to claim 1 or 2, the length from the polymer solution supply point of the pipe to the injection point to be treated water system, and wherein the residence time of the liquid supplied are those having more than one minute Dissolution / dilution device for polymer liquid.

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