JP2000240902A - Chemicals injection apparatus in multiple can installation system of boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly inject a proper amount of a pharmaceutical solution in a multiple can installation system without installing many pharmaceutical solution injection apparatuses. SOLUTION: An apparatus is adapted such that a plurality of boilers 1 are installed, and water supply to the boilers is done through a water supply passage 2 common to the boilers part of the way. In this instance, there are provided two systems of pharmaceutical solution injection apparatuses of a basic introduction of a pharmaceutical solution injection apparatus for basically introducing a pharmaceutical solution through basic pharmaceutical solution injection tube 4 and a predetermined amount introduction pharmaceutical solution injection apparatus for introducing a predetermined amount of a pharmaceutical solution through a predetermined amount pharmaceutical solution injection tube 5. The predetermined amount pharmaceutical solution injection tube 5 is connected with the common water supply passage 2, whereby a pharmaceutical solution is injected at a predetermined part for water supply of many boilers 1 by injecting the pharmaceutical solution to the common water supply passage 2, and the basic pharmaceutical solution injection tube 4 is connected, branched for each boiler and basically introduces a predetermined amount of the pharmaceutical solution to the boilers subjected to full blowing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical injection device in a boiler multi-can installation system.

[0002]

2. Description of the Related Art In a boiler, a chemical is injected into a boiler in order to prevent corrosion and scale adhesion in a can. There are two types of chemical liquid injection into the boiler: basic injection, which is performed when the entire water is blown and the canned water is replaced, and quantitative injection, which is injected at a fixed rate with respect to the water supply. In the case of basic injection, it is necessary to inject the chemical solution to the predetermined concentration with respect to the non-concentrated can water. Since the concentration is performed, the amount of the chemical solution required for the supplied water amount is small. For this reason, in the chemical dosing device, the amount of chemical injection in the case of basic injection and the amount of chemical injection in the case of fixed amount injection are set, and when water is supplied after all blows are performed, the amount of basic injection and other water supply In the case of, the chemical solution is injected so as to have the concentration of the fixed amount.

[0003] Further, by installing a plurality of small boilers and operating the required number of boilers, a multi-can installation of a boiler that always keeps high efficiency is widely performed. Even in the case of multi-can installation, one set of chemical dosing device is provided for each boiler, and the basic dosing amount and the fixed dosing amount are set for each dosing device, so that each boiler has a basic dosing amount. It is common to perform input and quantitative input. However, installing a large number of dosing devices has problems such as increased costs, complicated structure, and increased management labor.
There has been proposed a system for injecting a chemical solution into a plurality of boilers using a single chemical injection device. In this method, the chemical injection pipe is branched and connected to each boiler, and the chemical liquid is injected into each boiler with one chemical injection device, or the chemical liquid is injected into the water supply tank common to each boiler. Then, a chemical solution is injected into the water supply of all the boilers.

However, when a single chemical injection device is used to inject a chemical into a multi-can boiler, it is not possible to change the amount of the chemical to be injected between a basic injection and a fixed injection. Infusion of chemicals cannot be performed. Without proper chemical injection, water quality management cannot be complete,
Corrosion will occur in the boiler can. For this reason, in order to always inject a proper amount of the chemical solution, one set of chemical injection device must be provided for each boiler.

[0005]

The problem to be solved by the present invention is that, in a multi-can installation system of a boiler, an appropriate amount of base injection and fixed amount injection with different required chemical injection amounts are required. A liquid medicine can be injected, and an injection of an appropriate amount of the liquid medicine is performed with a minimum amount of a liquid injector.

[0006]

A plurality of boilers are installed, and water is supplied to the boilers halfway through a common water supply path common to each boiler. Two sets of chemical dosing devices are provided: a basic dosing device to perform the dosing, and a metering dosing device to perform the metered dosing of the drug solution through the metering dosing tube, and the metering dosing tube is connected to the common water supply path, By injecting the chemicals into the common water supply path, the chemicals are injected at a fixed rate with respect to the water supply of many installed boilers, and the basic chemical injection pipes are branched and connected for each boiler, and all blows are performed. A predetermined amount of chemical solution is basically charged into the boiler.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a flow chart of a boiler multi-can installation system according to an embodiment of the present invention. In this embodiment, five boilers 1 are installed in parallel, and the boiler operation control device 1
Reference numeral 2 denotes a multi-can installation system that determines the number of boilers that perform combustion in accordance with the required amount of steam and burns the required number of boilers. Water is supplied to the boiler 1 through a common water supply path 2 including a water supply tank, a water supply pipe, a water supply pump, and the like common to each of the boilers, and the individual boilers are branched from the common water supply path 2 to the respective boilers. This is performed through the branch water pipes 3 connected to each other. The injection of the chemical solution into the boiler is performed using a basic dosing device and a fixed dosing device.
It is performed with a chemical injection device of the system.

The metering dosing device is performed through a metering tube 5 having one end connected to the chemical tank 10 and the other end connected to the common water supply path 2. Is provided with a chemical injection pump 9 for metering.

The chemical dosing device for basic dosing is performed through a basic chemical dosing pipe 4 having one end connected to the chemical liquid tank 10 and the other end branched midway and connected to the branch water supply pipe 3 of each boiler. A base injection pump 8 is provided at a portion of the base injection pipe 4 before branching. A chemical injection control valve 6 is provided in each of the portions of the basic chemical injection pipe 4 after branching, and the basic injection of the chemical is performed only when the chemical injection control valve 6 is opened.

A chemical injection pump 8 for basic injection, an injection pump 9 for fixed amount injection, and an injection control device 7 electrically connected to each injection control valve 6 are provided. The chemical injection control device 7 is also connected to a flow meter 11 provided in the middle of the common water supply path 2 and a boiler operation control device 12 for controlling the operation of the boiler.
Based on information from the flow meter 11 and the boiler operation control device 12, the respective operations of the basic dosing pump 8, the fixed dosing pump 9, and each of the dosing control valves 6 are controlled.

The fixed amount of chemical solution is to inject the chemical solution at a constant rate with respect to the amount of water supplied to the boiler.
The chemical injection control device 7 calculates the required amount of the liquid medicine from the amount of water supply detected by the flow meter 11, and controls the operation of the fixed amount injection chemical injection pump 9 so that the required amount of the liquid medicine is injected.

During operation of the steam boiler, still water concentrates, and impurities in feedwater accumulate inside the boiler. For this purpose, all blows for discharging canned water are regularly performed to discharge impurities. Since the can water is not concentrated at all when the entire blow is performed, it is necessary to inject a chemical solution in the water supply in that case so as to have a higher concentration than that in the case of the fixed amount supply. Information that all the blows have been performed is sent from the boiler operation control device 12 to the chemical injection control device 7, and the chemical injection control device 7 performs a basic injection of the chemical solution into the boiler that has performed the full blow by using the chemical injection control valve. 6 is opened and the chemical injection pump 8 for basic introduction is operated to inject a predetermined amount of the chemical solution. Since the amount of water supply after all blows is constant, the amount of chemical liquid injected at the time of basic injection is the same every time.
Is operated for a predetermined time, thereby injecting a predetermined amount of the chemical solution.

When the injection amount of the basic solution is determined by the operation time of the injection pump 8 for basic injection, if a plurality of vapor discharge pipes 6 are opened at the same time, a correct amount of the chemical solution cannot be injected. Therefore, in the event that the basic injections overlap, the chemical injection control device 7 does not open the plurality of chemical injection control valves 6 at the same time, and starts the basic injection on the other side after the end of the basic injection. By doing so, it is possible to inject a proper amount of the drug solution.

[0014]

According to the present invention, even in a multi-can installation system in which a large number of boilers are installed, an appropriate amount of chemical solution can always be injected with only two sets of chemical injection devices, and water quality can be improved. The effect of preventing corrosion in the boiler can can be obtained by perfecting the management.

[Brief description of the drawings]

FIG. 1 is a flowchart of a boiler multi-can installation system according to an embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Boiler 2 Common water supply path 3 Branch water supply pipe 4 Basic chemical injection pipe 5 Fixed quantity chemical injection pipe 6 Chemical injection control valve 7 Chemical injection control apparatus 8 Basic injection chemical injection pump 9 Fixed quantity injection chemical injection pump 10 Chemical liquid tank 11 Flow meter 12 Boiler operation control device

Claims (2)

[Claims] A plurality of boilers are installed, water is supplied to the boiler halfway through a common water supply path, and water is supplied to each boiler through a branch water supply pipe branched from the common water supply path. , Which has a basic dosing injection pump and has a basic dosing device for dosing the basic solution through the basic dosing tube, and a quantitative dosing pump which has a fixed dosing pump and performs fixed dosing of the solution through the fixed dosing tube By providing two systems of the dosing device for dosing, the dosing tube of the dosing device is connected to the common water supply path, and the liquid medicine is injected into the common water supply path. A fixed quantity of chemical injection pumps can inject chemicals at a fixed rate to the water supply of many installed boilers, and the basic injection pipes of the basic injection chemical are branched and connected to each boiler. Aside
A dosing control valve provided in the middle of each basic dosing tube after branching, and a dosing control device connected to each dosing control valve to control opening and closing of the dosing control valve is provided. Controlling the opening and closing of each chemical injection control valve allows one basic injection chemical injection pump to perform basic injection of chemical liquid for each individual boiler. apparatus. 2. The chemical dosing device in the boiler multi-can installation system according to claim 1, wherein the chemical dosing control device is set to prohibit a plurality of chemical dosing control valves from being simultaneously opened. A chemical injection device in the boiler multi-can installation system.