JP2003225651A - Automatic priming maintenance system and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic priming maintenance system and a device for a chemical feed pump. <P>SOLUTION: This automatic priming maintenance system is interposed as a chemical feed circuit in a water treatment path and allows a pump to start up at all times by disposing a priming mechanism having a water conditioning function always on the pump when the pump is started or restarted as necessary. Therein, a self-priming vessel is disposed, the chemical feed pump is operated in the vessel so as to control a communication water level, and the supply water level to the chemical feed pump is always assured and the cut-off of water vein is prevented by linking the self-priming vessel to a mother liquid tank. Thereby, this system can cope with the gas lock and can start the pump and, when a circulation pump is used as the pump attached to the mother liquid tank, the homogenization of chemicals can be attained. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a priming system and a device using the priming system, which is always suitable for starting or restarting a pump when a chemical is injected in a water treatment process.

[0002]

2. Description of the Related Art In recent years, when a target treated water is obtained from raw water in a water treatment process, many kinds of treatment chemicals are used in various treatment processes which are often stepwise depending on the nature of the raw water. In particular, when drinking well water is treated, drinking well water is usually received in a raw water tank, further treated by a filtering device, and then transferred to a treated water tank for storage. During these steps, chemical treatment is usually performed in many cases, and a chemical liquid injection unit is installed. When injecting these chemicals, intermittent control injection is often employed in addition to the pump that is always operating.

In the intermittent chemical dosing process, it is important that the chemical dosing pump is kept in an immediate response state to the constant start command,
Further, when injection accuracy is required, careful control of the supply water level communicating with the chemical injection pump is also required.
On the other hand, in a process in which a particularly long standby state is predicted, a phenomenon caused by an abnormality in the pipe that occurs during the standby time, for example, a trouble due to disconnection of a water vein due to a so-called gas lock caused by generated gas occurs Can be lost and is a major concern in the water treatment process.

As measures against such troubles, various measures against priming have been generally proposed. For example, priming is unnecessary by injecting priming water to discharge the air in the pump case, changing the inflow path using a flow path switching valve, and devising the volume to the inlet to the pump case Japanese Unexamined Patent Publication No. 8-121863 has been reported. However, these methods alone do not provide a complete solution that can deal with so-called gas locks.

Further, in the case of a trouble such as a gas lock caused by chlorine gas which naturally occurs in piping such as a chemical to be injected, for example, sodium hypochlorite solution, a diaphragm pump is directly connected for the purpose of automatic degassing. The scheme has been announced. This method is effective for generating a small amount of gas, but when the amount of generated gas is large, there is a drawback that the pump runs idle and satisfactory operation guarantee cannot be obtained.
Not safe. Further, a high-tech-led system in which the injection amount and the ejection amount are controlled by PID has been announced, but it is difficult to be adopted for general purpose since it is extremely expensive. Under these circumstances, some measures are required as a substantially stable priming system, which is simplified and the existing system is almost unchanged.

[0006]

As described above, it is difficult to say that the currently announced various methods are sufficient solutions, and in particular, in order to adapt to existing water treatment equipment, it is necessary to introduce corresponding measures. Becomes Furthermore, difficulties are expected in terms of requiring new operations. For this reason, a unique priming system that can be easily applied to existing processes and is compatible with new technological processes, with a focus on a stable priming system, while being able to always start the target chemical injection pump. , And investigated an inexpensive method that facilitates starting or restarting the pump. According to this system, it is expected that the improvement of the conventional method will be easy and that it will contribute to the realization of reuse rather than the new disposal of equipment.

[0007]

Means for Solving the Problems The inventors of the present invention have diligently studied from such a viewpoint in order to achieve the above-mentioned object, and have a self-priming tank having a self-priming tank incorporating a system capable of reliably maintaining a specific water level. The present invention has been found to be easily achieved by providing a mother liquor tank equipped with a pump and a control injection pump that operates in conjunction with the pump.

That is, the gist of the present invention is to provide a priming mechanism which is inserted as a chemical liquid injection circuit in a water treatment route and has a constant water regulating function for the pump when the pump is started or restarted as necessary. It is an automatic priming maintenance system that is characterized by being attached.

Various types of priming mechanism having a constant water regulating function for the pump shown here can be considered, but representative examples thereof are as follows. This is a system that installs a self-priming tank that holds a communication water level that can be activated with respect to a chemical injection pump and a mother liquor tank that is equipped with a liquid delivery pump that is effective and controllable for this purpose. Further, in order to always maintain a communicable water level that can be activated with respect to the pump and at the same time uniformly hold the chemical solution, the chemical solution from the mother liquor tank to the self-priming tank is constantly circulated and supplied.

In the present invention, when precise injection of a chemical solution is required, a level sensor specially provided in the self-priming tank for precisely controlling the communicating water level of the self-priming tank is used to feed the liquid on the mother liquor tank side. This can be achieved by controlling the pump. Furthermore, if the mother liquor tank equipped with a circulation type liquid feed pump is used to maintain a constant water level for communication with the pump of the self-priming tank that is involved in direct injection and to maintain homogenization of all chemical liquids, concentration changes This is an extremely effective means for delivering a chemical solution that is likely to cause. Especially when in a standby state for a long time, the circulation of the chemical liquid by the circulation type liquid feed pump system prevents the adverse effects such as the concentration change of the chemical liquid component in the chemical liquid tank and its connecting pipe or the deposition on the tank or the pipe wall. It is also effective in that it can be done.

The application of the system of the present invention can be applied to any field in which precision injection is required, but is particularly suitable for injection of a drug which is apt to cause gas lock. In particular, it can be said that it is a very convenient system for a field in which a small amount of a water-soluble drug needs to be accurately pumped in-line. A typical example is intermittent injection of sodium hypochlorite solution, which is necessary for the oxidation of iron and manganese contained in well water. On the other hand, it can be adopted as a reliable method for precision injection as in the case of controlled injection of coagulant such as aluminum sulfate or PAC. In addition, it can be similarly adopted in the field of wastewater treatment.

In the present invention, in order to connect the pump to the self-priming tank, it is necessary to take care so that the water vein is not always cut off, and the chemical solution is always sucked into the pump from the bottom of the self-priming tank. It is important to completely eliminate the inclusion of gas. For this reason, a degassing mechanism can be attached to the water guiding circuit as needed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The configuration of a typical example 1 in which the above-described automatic priming water conservation system of the present invention is implemented is shown in FIG. In the example, a chemical injection device of sodium hypochlorite liquid into well water is shown therein, and an embodiment of the present invention is shown therein. First, the mother liquor tank T1 is made of PVC with a plate thickness of 3 mm and has a length of 50 cm, a height of 100 cm, and a volume of 2 cm.
A 50 liter V-equipped container was manufactured. For the purpose of installing it on the top plate of this container, the height and width are 20 cm and the height is 30 c.
A PVC tank T2 having a volume of 12 liters and a plate thickness of 12 liters was manufactured as a self-priming tank and attached. Inside the self-priming tank, a return pipe was provided so that the water level could be kept at a maximum of 25 cm, and a pipe was provided in the mother liquor tank T1. On the other hand, EHB manufactured by Iwaki Co., Ltd.
Two -10VC metering pumps are designated as P1 and P2, respectively.
The arrangement of the present invention was completed as shown in FIG.

The pump P1 comprises a mother liquor tank T1 and a self-priming tank T.
2 tanks, each tank being filled with 6% sodium hypochlorite solution. This system is used to connect to the oxidation process of the iron and manganese components of the actual well water, and P1 is 0.4 cc / min and P2 is 0.2 cc / m.
It was set to in and the operation was continued for one week. As for the water level in the self-priming tank, the fluctuation range was within about 1 cm, and there was no fluctuation in the amount of inflow to P2, and the quantitative injection was maintained. At this time, the residual chlorine content during the oxidation step was continuously measured, but 0.5 mg / l was constantly maintained, and no problem occurred. On the other hand, in the conventional method using only the P1 pump of the direct injection method, the residual chlorine concentration in the process started to change after about 3 hours, and the initial chlorine concentration was 0.
The pump is unstable even when set to 2 cc / min,
It was 1.4 mg / l and it was found that proper drug administration could not be performed.

Further, FIG. 2 shows a configuration of a typical example 2 in which the automatic priming water conservation system of the present invention is implemented.
In the example, an example of in-line injection into an adsorption filtration tank in the oxidation adsorption process of iron and manganese by chemical injection of sodium hypochlorite solution into existing well raw water with many gas lock troubles has been shown. Is. In the representative example 2 of the present invention, the mother liquor tank T1 is made of vinyl chloride having a thickness of 3 mm, and has a length of 40 cm, a height of 70 cm, and a volume of 11 cm.
A 2 liter open container was made. As a self-priming tank used integrally with this, the height and width are 15 cm and height is 30 cm.
A vinyl chloride tank T2 having the same plate thickness and having a volume of 6.75 liters in cm.

In the self-priming tank, a level sensor LC is set so that the water level can be kept at a maximum of 25 cm ± 1, and a metering pump P is installed.
Linked to 1. The pump P1 is connected near the bottom of the mother liquor tank T1 and the mother liquor tank T1 is connected through the chemical transfer of the pump.
And the drug solution in the self-priming tank T2 is shared and held. The two metering pumps P1 and P2 are EHB-10 manufactured by Iwaki Co., Ltd., respectively.
The configuration of the present invention was completed with VC as the arrangement order as shown in FIG.

The pump P1 comprises a mother liquor tank T1 and a self-priming tank T.
It operates based on the level sensor LC between 2 and both tanks are each filled with 6% sodium hypochlorite solution.
P1 is set to 1.2 cc / min to oxidize the iron and manganese components in the actual well raw water using this system.
2 was set to 1.0 cc / min and the 2-inch in-line injection operation was continued for 10 days. As a result, the fluctuation level of the water level in the self-priming tank was within about 1 cm, and there was no fluctuation in the inflow amount to P2, and the quantitative injection was maintained. At this time, the residual chlorine content in the oxidation step was continuously measured, but 0.5 mg / l was constantly maintained, and no gas lock problem occurred.

The first feature of the present invention is that it is a system configuration aiming at precise injection of a chemical solution and can be easily achieved. That is, it is possible to achieve the object within a practical range without adding any special improvement to the conventionally adopted system and without newly adding special advanced equipment. The applicable range is not particularly limited and can be adopted as various medicinal injection means.

The second feature of the present invention is that the gas lock, which is liable to be spontaneously decomposed and which is likely to occur in the chemical injection process, can reliably restart the pump to avoid the chemical injection failure due to the idling of the pump. . In chemical injection with generation of easily decomposable gases such as iron and manganese in the raw water of wells, troubles due to gas locks may lead to serious situations depending on the application. In particular, in the water distribution system for hospitals and pharmaceutical lines, no troubles can be recognized in the water treatment line because the quality of water is precisely required to be guaranteed. With the advent of the system of the present invention, it becomes easier to take reliable measures.

[0020]

Industrial Applicability The present invention digitally improves the accuracy of a chemical liquid injection system required to perform a water treatment process which has been conventionally performed, and ensures a reliable operation. It provides a system. At the site of the water treatment process, the role of the chemical injection pump, which is in charge of the center of the treatment process, is extremely important under the current situation that unmanned operation is the main tendency. For this purpose, the system must be constructed on the assumption that each device operates reliably according to the set control method.

The system of the present invention fulfills the necessary and sufficient conditions for the unattended operation of the water treatment process. Especially, for the trouble of the chemical injection pump due to the gas lock caused by the easily decomposable chemicals, etc. It has been completed as a technical configuration that can be reliably prevented. Above all, I am convinced that the configuration of the self-priming tank that secures the communication water level to the direct injection pump and the mother liquor tank that backs up and cooperates with this tank can contribute as an industrially useful system.

[Brief description of drawings]

FIG. 1 is a set showing an example in which an automatic priming water maintenance system of the present invention is incorporated.

FIG. 2 is a flow diagram in which an example of the automatic priming maintenance system of the present invention is applied to an existing inline.

[Explanation of symbols]

T1 mother liquor tank T2 self-priming tank V vent P1 liquid feed pump P2 chemical injection pump L1 level 1 L2 level 2 L 2 inch raw water pipe Sodium hypochlorite solution LC level sensor

Claims (6)

[Claims] 1. An automatic priming system, which is inserted as a chemical liquid injection circuit in a water treatment route and is provided with a priming mechanism having a constant water regulating function for the pump when the pump is started or restarted as necessary. Priming water conservation system. 2. The automatic priming maintenance system according to claim 1, wherein a mother liquor tank provided with a controllable liquid feed pump is installed in the priming process. 3. The automatic priming according to claim 1, comprising a self-priming tank for holding a communication water level that can be activated with respect to the pump, and a mother liquor tank provided with a pump for feeding the self-priming tank. Conservation system. 4. The automatic priming water conservation system according to claim 1, wherein the pumping of the liquid is controlled by detecting and controlling the communication water level of the self-priming tank. 5. The mother liquor tank equipped with a circulation type liquid feeding pump in order to keep the communication water level of the self-priming tank and the uniformity of the chemical liquid quality constant. Priming water conservation system. 6. An automatic priming maintenance apparatus, which is performed by using the system according to any one of claims 1 to 5.