JPH0672650U - Chemical dosing device - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a small-sized, low-cost chemical injection device that can supply a diluted chemical solution to a diluted tank without interrupting the chemical injection of the diluted chemical solution in the diluted tank. [Structure] In a chemical injection device having a chemical solution tank 2 and a diluting tank 1, which draws a diluted chemical solution from the diluting tank and doses it, a diluting water is supplied to the diluting tank 1 at an intermediate upstream position. A flow valve 10 and a line mixer 11 are provided downstream, and a liquid feed pipe 3 for feeding a drug substance solution in a drug solution tank by a pump is connected between the constant flow valve 10 of the water feed pipe and the line mixer 11.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This device is used to dilute boilers and other chemicals into a boiler, to inject diluted chemicals to a cooling device, to inject a deodorant stock solution to a spray device, to supply acid, The present invention relates to a chemical injection device that dilutes and injects a chemical solution such as a pH adjuster such as an alkaline solution supplied to a reactor.

[0002]

[Prior art]

2. Description of the Related Art A chemical injection device that has a chemical liquid tank and a diluting tank and draws a diluted chemical liquid from the diluting tank and injects the chemical is known in the related art. The above-mentioned known pump metering type chemical dosing device has a diluting tank 1 and a drug solution tank 2 as shown in FIG. 2. To adjust the diluting drug solution, the raw drug solution in the drug solution tank is measured by a constant flow rate pump P _A. Then, while supplying it to the diluting tank 1 through the liquid supply pipe 3, the amount of diluted water for diluting the above drug substance solution to a predetermined concentration is supplied to the diluting tank 1 through the water supply pipe 4, and the drug substance is driven by the electric stirrer 5 in the diluting tank. The liquid and diluted water are sufficiently stirred and mixed to form a diluted chemical liquid, and the chemical is injected into the device by the chemical injection pump P _B and the injection pipe 6.

[0003]

[Problems to be solved by the device]

In the above-mentioned chemical injection device, the chemical injection pump P _B is operated from the dilution tank until the stock solution and the diluted water are supplied to the dilution tank and the stirrer stirs and mixes them to obtain the diluted chemical solution of a predetermined concentration. Unable to dispense a dilute solution of constant concentration into the device. For this reason, a spare tank 7 is installed side by side, and when the diluted chemical solution having a predetermined concentration can be adjusted in the dilution tank, the solenoid valves V ₁ and V ₇ of the U-shaped communication pipe 8 connected to the bottom of the dilution tank and the spare tank are opened. When a part of the diluted drug solution in the diluting tank is introduced and filled in the spare tank and the level of the diluted drug solution in the diluting tank falls to the lower limit L, the solenoid valve V ₆ of the injection pipe ₆ is closed and the communication pipe 8 The solenoid valve V ₇ on the auxiliary tank side is opened, and the communication pipe 8 and the connection pipe 9 having one end connected to the communication pipe and the other end connected to the injection pipe 6 downstream of the solenoid valve V ₆ are connected. The diluted drug solution in the spare tank must be dosed to the device by the dose pump P _B.

That is, in the conventional chemical injection device, a spare tank is required in addition to the diluting tank and the chemical liquid tank, so that a large space is required for installation. In addition, a stirrer is needed to stir and mix the drug substance solution and the diluting water in the diluting tank and consumes electric power. Furthermore, the dilution process is performed by switching the solenoid valve, measuring the drug substance solution, measuring the diluted water, stirring, mixing, and replenishing the preliminary tank. The control circuit becomes more complicated because it needs to be equipped with a cap circuit that does not become abnormal even if a power failure occurs during the dilution process. Also, if the manual circuit is switched to the manual operation during the automatic dilution, the keep circuit is not released, which may cause an abnormality in the subsequent automatic dilution.

[0005]

[Means for Solving the Problems]

 The present invention was developed in order to solve the above-mentioned problems, and has a chemical solution tank and a diluting tank, and in a chemical pouring device for extracting a dilute chemical solution from the diluting tank and dosing the chemical, diluting water is diluted. Install a constant flow valve upstream of the water supply pipe and a line mixer downstream of the water supply pipe. It is characterized by being connected in between.

[0006]

【Example】

In FIG. 1, 1 is a diluting tank, 2 is a chemical solution tank, P _A is a constant flow pump for feeding the original drug solution in the chemical solution tank for dilution, and P _B is the diluting chemical solution in the diluting tank, which is dosed to the device. These are the same as the conventional device shown in FIG. A constant flow valve 10 is connected upstream and a line mixer 11 is connected downstream to a water supply pipe 4 for introducing diluted water into the diluting tank 1. The liquid feed pipe 3 for feeding the stock drug solution in the drug solution tank with the constant flow rate pump P _A is connected to the connection point 12 between the constant flow rate valve 10 and the line mixer 11 of the water supply pipe 4. The flow rate of the diluting water flowing into the diluting tank is kept constant by the constant flow valve 10. Therefore, the flow rate of the constant flow rate pump P _A for feeding the drug substance solution is determined so that the drug substance solution is added to the constant flow rate of diluted water to obtain the diluted drug solution of a desired concentration.

When the level of the diluted chemical liquid in the dilution tank 1 is lowered to the lower limit L of the level switch LS ₁ by chemical injection, the solenoid valve V ₄ of the water supply pipe ₄ is opened and the constant flow rate pump P _A is operated at the same time. Starting, the stock drug solution in the drug solution tank is supplied to a constant flow of diluted water at the connection point 12. The diluted water and the drug substance solution added thereto are stirred and mixed by the line mixer 11 to be a diluted drug solution having a predetermined concentration and flow into the dilution tank 1. R _e number of line mixer to 2300 or more. In this way, when the level of the diluted chemical in the dilution tank reaches the upper limit H of the level switch LS ₁ , the solenoid valve V ₄ is closed, the operation of the constant flow pump is stopped, and the dilution process is finished.

In order to prevent the supply amount of the drug substance solution supplied to the diluting water from varying above and below the level of the drug substance solution in the drug solution tank, the liquid supply pipe 3 has a back pressure downstream of the constant flow pump P _A. A back pressure valve 13 of about 1 kg / cm ² is connected, and a flow meter 14 is provided upstream of the constant flow valve in the water supply pipe 4 in order to confirm the set value of the constant flow valve 10 that makes diluted water a constant flow rate. Preferred. Further, the above-mentioned dilution process is controlled automatically by an electric circuit, and in that case, either the solenoid valve V ₄ of the dilution water or the constant flow rate pump P _A for feeding the drug substance tripped. or as a full stop time, when the dilution water is not diluted process is completed within the scheduled time, such as water outages, stop the dilution step, and outputs an alarm, failure of dilution water solenoid valve V _4, etc. If the dilution water does not stop with, the warning is output by HH of the level switch, and if the dilution process is not performed due to a failure, the warning is output by LL of the level switch. Record and display the number of times the operation was performed. Further, when the level switch of the chemical liquid tank is set to L, an alarm of a chemical liquid reception request may be output.

[0009]

[Effect of device]

 As is clear from the above, the present invention provides the line mixer 11 in the middle of the diluting water supply pipe 4 reaching the diluting tank, adds the drug substance solution upstream of the line mixer, and stirs and mixes with the line mixer to obtain a predetermined concentration. Since the diluted solution is supplied to the diluted tank, the diluted process can be performed while performing chemical injection. Therefore, since a spare tank is not necessary and the diluting tank may be small, it can be downsized and installed in a small space. In addition, since an inexpensive line mixer stirs and mixes the drug substance solution and diluted water, and the number of solenoid valves used is small, it can be provided at low cost. In addition, even if a power failure occurs during the automatic dilution process, no complicated keep circuit is required, and the dilution process is performed when the diluted chemical in the dilution tank reaches the level switch L next time.

[Brief description of drawings]

FIG. 1 is a schematic view of an embodiment of the chemical injection device of the present invention.

FIG. 2 is a schematic view of a conventional pump metering type chemical dispensing device.

[Explanation of symbols]

1 Diluting tank 2 Chemical liquid tank 3 Liquid supply pipe 4 Water supply pipe 6 Injection pipe 10 Constant flow valve 11 Line mixer P _A Constant flow pump P _B Chemical injection pump

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A chemical injection device having a chemical solution tank and a diluting tank, wherein a diluting chemical solution is extracted from the diluting tank and dosed, and a constant flow valve is provided upstream in the middle of a water supply pipe for supplying the diluting water to the diluting tank. A chemical injection device characterized in that a line mixer is provided on the downstream side, and a liquid feed pipe for feeding the drug substance solution in a drug solution tank by a pump is connected between the constant flow valve of the water feed pipe and the line mixer.