JP2017096380A - Instrument air supply facility and instrument air supply method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an instrument air supply facility capable of stably supplying instrument air as a backup in a case of a reduction in pressure of regular use instrument air.SOLUTION: An instrument air supply facility 1 comprises: a first air supply source 10; first air piping 11 to supply instrument air from the first air supply source 10 to a device 50 therethrough; a second air supply source 20; and second air piping 21 which is connected to the first air piping 11 to supply the instrument air from the second air supply source 20 to the device 50 therethrough. The first air piping 11 has: a pressure gauge 15 which measures pressure of the instrument air supplied from the first air supply source 10; and an air cut-off valve 16 which cuts off a supply of the instrument air from the first air supply source 10. When a pressure value measured by the pressure gauge 15 is lower than a predetermined value, the supply of the instrument air from the first air supply source 10 is cut off with the air cut-off valve 16 and the instrument air is supplied to the device 50 through the second air piping 21 with the second air supply source 20 activated.SELECTED DRAWING: Figure 1

Description

  The present invention relates to instrumentation air supply equipment, and instrumentation air that can stably supply instrumentation air to instrumentation equipment even when a pipe breakage or other emergency occurs. The present invention relates to a supply facility and a method for supplying instrument air using the facility.

  For example, in a dry copper smelting process, acidic gas containing sulfur oxides and nitrogen oxides is generated during smelting. The generated acid gas is drawn in at various places and discharged to the atmosphere in a detoxified state through a detoxification process in a detoxification facility.

  In the detoxification treatment in the detoxification facility, neutralization detoxification is carried out by adding an alkaline aqueous solution such as caustic soda or magnesium hydroxide to the acid gas, and then the dust is removed by a wet electrostatic precipitator provided continuously. Is released into the atmosphere.

  Now, the addition valve for adding an alkaline aqueous solution provided in such a detoxification facility is generally composed of a reverse-actuated automatic air-operated valve, which depends on the concentration of acidic gas to be drawn. The amount of alkaline aqueous solution added is adjusted.

  Instrumented air that operates the air-operated automatic valve is produced by a compressor and a dehumidifier (hereinafter collectively referred to as “instrumented air production device”). Instrument air produced by the instrument air production equipment is supplied to equipment at various locations through the instrument air piping, but the instrument air production equipment and regular instrument air pipes are damaged. When the air pressure decreases, valves and instrumentation devices that require instrument air become inoperable. In particular, in the case of an alkaline aqueous solution addition valve as used in the above-described detoxification treatment, since it is a generally reverse-acting air-operated automatic valve, the valve is fully closed due to a decrease in instrument air pressure, Alkaline aqueous solution cannot be supplied. Thereby, it becomes impossible to neutralize and remove the acidic gas, and even if it is a short time, the possibility that the acidic gas is discharged out of the system will be increased. In such a situation, the operation itself such as the smelting process must be stopped, and the operation efficiency is significantly reduced.

  In order to solve such a problem, for example, in Patent Document 1, when the N2 backup gas supply path is connected to the normal self-supply air path, and the normal self-supply air pressure drops below a specific value, the backup gas supply is performed. A method for automatically switching a three-way valve provided in a path and supplying instrument air downstream by this is disclosed.

  However, in the supply system as disclosed in Patent Document 1, when the instrument air is supplied through the N2 backup gas supply path based on the decrease in the self-supply air pressure, the check provided in the normal self-supply air path is used. When an abnormality occurs in the valve, the N2 back-up gas flows backward to the upstream side of the self-supply air path whose pressure is lower than that of the downstream side. In general, the upstream pipe is configured to be thicker than the downstream pipe. Therefore, when a back flow of the N2 backup gas occurs, the majority of the back side gas flows back, and gas or instrumentation is performed on the downstream target. Air cannot be supplied.

  Furthermore, with a check valve provided in such a self-supplied air path, it is difficult to check normality by performing maintenance and operation check during normal operation. There is a possibility that the problem that N2 back-up gas flows backward without acting as a check valve when the air pressure is lowered may occur.

JP 2006-275436 A

  The present invention has been proposed in view of such circumstances, and can stably supply instrumentation air for backup when the pressure of ordinary instrumentation air is reduced without causing backflow. The object is to provide instrumentation air supply equipment.

  (1) The first invention of the present invention is an instrument air supply facility for supplying instrument air to an instrument, and connects the first air supply source, the first air supply source, and the instrument. And a first air pipe for supplying instrument air from the first air supply source to the device, a second air supply source, and the first air pipe at a predetermined position. A second air pipe for supplying instrumentation air from the second air supply source to the device, and the first air pipe is supplied from the first air supply source. An air shut-off that is located upstream of the connection point between the pressure gauge for measuring instrument air pressure and the second air pipe, and shuts off the supply of instrument air from the first air supply source A valve, and when the pressure of the instrument air in the first air pipe measured by the pressure gauge falls below a predetermined value The supply of instrument air from the first air supply source is shut off by the air shut-off valve, and the second air is operated via the second air pipe. An instrument air supply facility, wherein instrument air is supplied from a supply source to the device.

  (2) According to a second aspect of the present invention, in the first aspect, the supply of instrument air from the first air supply source is blocked by the air shutoff valve, and the second air supply source is It is an instrument air supply facility in which the predetermined value of the pressure of the instrument air that operates is a value within the range of 0.4 MPaG to 0.7 MPaG.

  (3) According to a third aspect of the present invention, in the first or second aspect, an instrumented air storage tank is provided at a position downstream of the first air pipe where the pressure gauge is provided. Is an instrument air supply facility.

  (4) A fourth invention of the present invention is an instrument air supply facility according to any one of the first to third inventions, wherein the second air pipe is provided with an instrument air storage tank. is there.

  (5) A fifth invention of the present invention is an instrument air supply method for supplying instrument air to an instrument by an instrument air supply facility connected to the instrument, the instrument air supply facility comprising: A first air pipe for connecting the first air supply source, the first air supply source, and the device, and supplying instrument air from the first air supply source to the device; Two air supply sources, and a second air pipe connected to the first air pipe at a predetermined position for supplying instrument air from the second air supply source to the device. The first air pipe is located upstream of a connection point between a pressure gauge for measuring the pressure of instrument air supplied from the first air supply source and the second air pipe. And an air shut-off valve for shutting off the supply of instrument air from the first air supply source. Stops the second air supply source, operates the first air supply source, and supplies instrumentation air from the first air supply source to the device via the first air pipe. When the pressure of the instrument air in the first air pipe measured by the pressure gauge falls below a predetermined value, the air shut-off valve controls the instrument air from the first air supply source. The supply air is cut off, the second air supply source is operated, and instrumented air from the second air supply source is supplied to the device through the second air pipe. This is an instrument air supply method.

  (6) According to a sixth aspect of the present invention, in the fifth aspect, when the pressure of the instrumented air in the first air pipe measured by the pressure gauge is below a predetermined value, After the air supply source 2 is operated and the supply of instrument air from the second air supply source is started, the air shutoff valve waits for a predetermined time before the metering from the first air supply source. This is an instrument air supply method that shuts off the supply of instrument air.

  According to the present invention, it is possible to stably supply instrument air for backup when the pressure of normal instrument air is reduced without causing a backflow upstream.

It is a figure which shows an example of a structure of instrumentation air supply equipment. It is a figure which shows an example of a structure of instrumentation air supply equipment. It is a flowchart which shows the flow of the supply method of instrumentation air using instrumentation air supply equipment.

  Hereinafter, a specific embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment, A various change is possible in the range which does not change the summary of this invention.

<< 1. Instrument air supply equipment >>
The instrument air supply facility according to the present embodiment is for supplying instrument air to various devices provided with an automatic valve (air automatic operation valve) that is operated by instrument air, for example, provided in a detoxification facility. Is. Hereinafter, the device provided with the air automatic operation valve is simply referred to as “device” or “instrumentation device”.

  FIG. 1 is a diagram illustrating an example of the configuration of an instrument air supply facility according to the present embodiment. As shown in FIG. 1, the instrumentation air supply facility 1 supplies instrumentation air by connecting a first air supply source 10, and the first air supply source 10 and an instrument (instrumentation instrument) 50. A first air pipe 11, a second air supply source 20, and an instrument air from the second air supply source 20 connected to the first air pipe 11 at a predetermined position. The second air pipe 21 is provided.

  In the instrument air supply facility 1, the pressure gauge 15 that measures the pressure of the instrument air supplied from the first air supply source 10 and the first air supply source 10 in the first air pipe 11. And an air shutoff valve 16 for shutting off the supply of instrument air.

  Further, the instrumentation air supply facility 1 is provided with a control device 17 electrically connected to the pressure gauge 15, the air cutoff valve 16, and the second air supply source 20.

[First air supply source]
The first air supply source 10 is an air generation supply source that generates instrument air used by the device 50 and supplies the instrument air generated to the device 50. The first air supply source 10 is an air supply source that generates instrumentation air from the instrumentation air supply facility 1 and supplies it to the device 50 during normal operation, that is, a normal air supply source.

  The generation of instrument air as used in the present specification means obtaining a gas suitable for the operation of the device, and known means can be used as the generation means. For example, it can be generated by compressing the atmosphere and performing dust removal or dehumidification as necessary.

  A first air pipe 11 to be described later is connected to the first air supply source 10, and is connected to a device 50 that is an instrument air supply destination via the first air pipe 11.

[First air piping]
The first air pipe 11 is a pipe for connecting the first air supply source 10 and the device 50, allowing instrumentation air generated from the first air supply source 10 to pass therethrough, and supplying it to the device 50. is there. The first air pipe 11 is a pipe for supplying instrument air from the instrument air supply equipment 1 to the device 50 during normal operation, that is, a normal air supply pipe.

  The first air pipe 11 may be any one that connects the first air supply source 10 and the device 50 and can supply instrument air to the device 50, and is branched at the end. There may be. For example, a plurality of devices are installed as the device 50, and in the first air piping 11, a position immediately before being connected to the plurality of devices 50 (the end portion of the first air piping 11) is branched. As a configuration, instrument air may be supplied from the first air supply source 10 to each device 50. In such a case, in the branched first air pipe 11, a valve is provided at a position from the branch point to the connection to each device 50 to control supply of instrument air to the device 50 (ON / OFF). OFF control etc.) may be performed.

  Here, in the first air pipe 11, as described above, the pressure gauge 15 for measuring the pressure of the instrument air supplied from the first air supply source 10, and the first air supply source 10 from Air shutoff valves 16 that shut off the supply of instrument air are provided at predetermined positions.

(Pressure gauge)
The pressure gauge 15 measures the pressure of instrument air supplied through the first air pipe 11, that is, the pressure of instrument air passing through the first air pipe 11. The pressure gauge 15 is connected to a connection point between a second air pipe 21 (to be described later) and the first air pipe 11 (“P” portion in FIG. 1; hereinafter referred to as “connection point P”). The first air supply source 10 is provided on the upstream side from the above. Further, the pressure gauge 15 is provided on the upstream side of the first air pipe 11 with respect to a location where an air shut-off valve 16 described later is located.

  The pressure gauge 15 is not particularly limited as long as it can measure the pressure of air in the pipe, and the same one as a pressure gauge provided in a pipe of a normal factory facility can be used.

  The pressure gauge 15 measures the pressure of the instrument air passing through the first air pipe 11 continuously, intermittently, or at regular intervals, and the first air pipe 11 is connected to the device 50. It is possible to recognize a change with time of the pressure of the instrument air supplied through the air.

  In the instrument air supply facility 1, a control device 17, which will be described in detail later, is provided. The pressure gauge 15 is electrically connected to the control device 17, and the pressure of the instrument air measured by the pressure gauge 15. A signal relating to the value can be transmitted to the control device 17.

(Air shut-off valve)
The air shutoff valve 16 is a valve that shuts off the flow of instrument air supplied from the first air supply source 10 via the first air pipe 11. The air shutoff valve 16 is located upstream of a connection point P between the second air pipe 21 and the first air pipe 11 described later in the first air pipe 11, and is located on the first air pipe 11. The pressure gauge 15 is provided downstream of the position where the pressure gauge 15 is provided.

  The air shut-off valve 16 can be configured as an ON / OFF valve that performs only opening / closing of the valve and controls only ON / OFF of the passage of instrumentation air in the first air pipe 11. .

  The air shutoff valve 16 is in the “open” state based on the pressure value of the instrument air supplied from the first air supply source 10 via the first air pipe 11 measured by the pressure gauge 15 described above. Alternatively, control of the “closed” state is performed, and the instrument air is passed through the first air pipe 11. Alternatively, the passage of instrument air is blocked. The flow of instrumentation air supply control based on opening and closing of the air shutoff valve 16 will be described in detail later.

  In the instrumentation air supply facility 1, the control device 17 is provided as described above, and the air shutoff valve 16 is electrically connected to the control device 17, and the control device 17 opens and closes the air shutoff valve 16. It is configured to be able to transmit a signal related to the control.

  Further, the air shutoff valve 16 is not limited to the ON / OFF valve configuration. For example, the valve opening / closing degree is 30%, 50%, 70% (Note that the opening degree is 100% when the valve is fully open. The degree of opening of the valve may be controlled such that the degree of opening is 0%). By configuring the air shutoff valve 16 as a control valve in this way, the supply of instrument air from the first air supply source 10 via the first air pipe 11 based on the control of the degree of opening and closing of the valve. The amount can also be controlled.

  The air shut-off valve 16 is preferably a reverse operation type. Because it is a reverse-actuated valve, it will operate on the “closed” side even if the driving force is insufficient when the normal instrumentation air, which will be described in detail later, falls and becomes emergency, the low pressure Thus, it is possible to reliably block the flow of normal instrument air. Furthermore, by being reversely operated, even when the control device 17 breaks down or when a malfunction occurs in the signal system between the control device 17 and the air shut-off valve 16, the “closing” operation can be easily performed. Therefore, instrument air can be reliably shut off.

[Second air supply source]
Similar to the first air supply source 10, the second air supply source 20 generates instrument air used by the device 50 and supplies the generated air to the device 50. Is the source. The second air supply source 20 is used when the supply of instrument air from the first air supply source 10 is reduced for some reason, such as damage to the first air pipe 11, which is a normal air supply pipe. In addition, it is an emergency air supply source that is operated based on a drop in the pressure of the instrument air. The flow up to the operation of the second air supply source 20 will be described in detail later.

  A second air pipe 21 to be described later is connected to the second air supply source 20, and the instrument air is supplied to the instrument 50 to which the instrument air is supplied via the second air pipe 21. It is a configuration to be supplied. More specifically, instrument air generated from the second air supply source 20 first passes through the second air pipe 21, and then at a predetermined position with the second air pipe 21. It passes through the connected first air pipe 11 and is supplied to the device 50 connected to the first air pipe 11.

  In the instrumentation air supply facility 1, the control device 17 is provided as described above, and the second air supply source 20 is electrically connected to the control device 17 and measured by the pressure gauge 15 described above. The operation or stop of the second air supply source 20 is configured to be automatically controllable according to the pressure value or the valve opening / closing operation of the air shutoff valve 16.

[Second air piping]
The second air pipe 21 has one end connected to the second air supply source 20 and the other end connected at a predetermined position in the first air pipe 11 (connection point P). Therefore, instrument air generated from the second air supply source 20 passes through the second air pipe 21 and is then supplied from the point of the connection point P to the device 50 via the first air pipe 11. The As described above, the second air pipe 21 is a pipe for sending instrument air from the second air supply source 20 which is an emergency air supply source to the device 50, that is, emergency air. Supply piping.

  In the present embodiment, the example in which the second air pipe 21 is connected to the first air pipe 11 at the connection point P is shown, but the present invention is not limited to this. For example, by connecting the other end of the second air pipe 21 directly to the device 50, the second air supply source 20 and the device 50 are connected only by the second air pipe 21. The instrument air may be supplied directly to the device 50 via the second air pipe 21.

[Control device]
The control device 17 supplies instrumentation air from the second air supply source 20 based on a decrease in the supply amount of instrumentation air supplied to the device 50 from the first air supply source 10 or a decrease in supply pressure. To control.

  In the instrument air supply facility 1, the control device 17 is electrically connected to the pressure gauge 15 on the first air pipe 11 and the air shutoff valve 16. Thereby, the control apparatus 17 receives the signal regarding the measured value of the pressure of the instrumentation air from the 1st air supply source 10 which passes the inside of the 1st air piping 11, and is based on the measured value of the pressure. Thus, a signal for instructing opening / closing of the air shutoff valve 16 can be transmitted to the air shutoff valve 16.

  Specifically, when the control device 17 receives a signal related to the pressure value of the instrumented air measured by the pressure gauge 15, the control device 17 transmits the signal continuously or intermittently or every certain time. The pressure value data over time can be recorded. The control device 17 monitors the pressure value fluctuation based on the pressure value data with time, and the pressure of the instrument air supplied from the first air supply source 10 via the first air pipe 11 is a predetermined value. It is determined whether or not the pressure has fallen below (whether or not the pressure has become low). When the control device 17 determines that the pressure of the instrumentation air has fallen below a predetermined value, the control device 17 next opens the air shutoff valve 16 in order to shut off the flow of instrumentation air through the first air pipe 11. An instruction signal is transmitted to close the valve.

  The control device 17 is electrically connected to the second air supply source 20. Thereby, the control apparatus 17 can control operation | movement or a stop of the 2nd air supply source 20 which is an emergency air supply source.

  Specifically, as described above, for example, when an emergency situation occurs in which the pressure value of instrumentation air supplied from the first air supply source 10 via the first air pipe 11 falls, the control device 17 When the air shut-off valve 16 is closed based on the pressure value from the pressure gauge 15, next, a signal for starting generation and supply of instrument air is transmitted to the second air supply source 20, The second air supply source 20 is operated. Thereby, the situation where instrumentation air is no longer supplied to the device 50 can be avoided.

  Thus, in the present embodiment, the opening and closing of the air shutoff valve 16 is automatically controlled according to the pressure value of the instrument air in the first air pipe 11, and the second air supply source 20 By being configured to automatically control operation, a sufficient amount of instrument air from the emergency second air supply source 20 can be generated without causing a reverse flow upstream. 50. As a result, normal instrumentation air becomes low pressure, and even in an emergency where the required amount of instrumentation air could not be supplied to the device 50 in the past, the instrumentation air can be stably and continuously supplied. Can continue to supply.

[Other configurations]
(Instrument air storage tank)
Although not an indispensable aspect, in the instrumentation air supply facility 1, an instrumentation air storage tank (air receiver tank) may be provided at a predetermined location.

  For example, when the first air pipe 11 that is a normal air supply pipe is damaged and the degree of the damage is large, or when the instrument 50 consumes a large amount of instrument air, the first air pipe 11 is used. The pressure of instrumentation air from the air supply source 10 may drop rapidly. In preparation for such a case, by providing an instrumentation air storage tank at a predetermined location, it becomes possible to store instrumentation air in the instrumentation air storage tank in advance. Even immediately after the air pressure drops or immediately after the air shutoff valve 16 is closed as described above, the instrument air is stably supplied to the device 50 for a certain period of time. You can continue.

  FIG. 2 is a diagram illustrating an example of the configuration of the instrumentation air supply facility 1 in which an instrumentation air storage tank is installed. For example, as shown in the block diagram of FIG. 2, in the instrumentation air supply facility 1, the instrumentation air storage tank 30 is located on the path of the first air pipe 11 from the location where the pressure gauge 15 is provided. It can be provided at a downstream position.

  With respect to the installation location, in the configuration example shown in FIG. 2, the instrument air storage tank 30 is provided downstream from the location where the pressure gauge 15 is provided and further downstream from the location where the air shutoff valve 16 is provided. However, the present invention is not limited to this. For example, the first air pipe 11 may be provided at a location between the pressure gauge 15 and the air shutoff valve 16. In the configuration diagram of FIG. 2, a position on the path of the first air pipe 11 and downstream of the connection point P with the second air pipe 21, that is, the instrument 50 that uses instrument air. It is also possible to install an instrumentation air storage tank at an adjacent position, but in such a case, unless a pipe that bypasses the installed instrumentation air storage tank is provided, the instrumentation air storage tank is repaired. There is a possibility that the supply of instrument air may be interrupted during replacement.

  Further, the instrument air storage tank 30 may be provided on the path of the second air pipe 21. By providing the instrument air storage tank on the path of the second air pipe 21 in this way, not only the rapid decrease in the pressure described above, but also the pressure fluctuation that occurs when the air is supplied from the second air supply source 20 is observed. It can also be absorbed.

In the instrument air supply facility 1, the number of instrument air storage tanks 30 is not particularly limited. For example, only one instrument air storage tank 30 may be installed at the location shown in the configuration diagram of FIG. A plurality of instrument air storage tanks 30 may be provided in total. In addition, the capacity of the instrumentation air storage tank 30 is not particularly limited, and is preferably determined as appropriate based on the required air amount calculated from the total amount of air used by the device 50 to which instrumentation air is supplied. For example, a tank having a capacity of 0.4 m ³ can be installed as the instrumented air storage tank 30.

  Moreover, when providing the instrumentation air storage tank 30, in consideration of work, such as repair and replacement | exchange of the instrumentation air storage tank 30, you may provide a shut-off valve in each before and behind the installation location. In the configuration diagram of FIG. 2, the shut-off valves 31 a and 31 b provided before and after the instrument air storage tank 30 installed on the path of the first air pipe 11 are used when the instrument air storage tank 30 is repaired or replaced. It is a valve for shutting off the flow of instrument air. As described above, by providing the shutoff valves 31a and 31b before and after the installation location of the instrument air storage tank 30, it is possible to efficiently perform repairs and replacement work while preventing leakage of instrument air. At this time, the supply of instrumentation air to the device 50 can be continued using the second air supply source 20.

≪2. Instrument air supply method with instrument air supply equipment≫
Next, a method for supplying instrument air for supplying instrument air to the device 50 that uses instrument air using the instrument air supply facility 1 described above will be specifically described.

[About control flow]
When supplying instrument air from the instrument air supply facility 1 to the device 50 that uses instrument air, it is required to stably supply a certain amount of the instrument air. The device 50 that uses instrument air is, for example, various types of equipment that includes an automatic valve (air operated valve) that is operated by instrument air. Specific examples include chemical addition equipment such as an alkaline aqueous solution provided in a detoxification facility for neutralizing and detoxifying acidic gas containing sulfur oxide, nitrogen oxide, and the like.

  By supplying instrumentation air stably to a chemical addition device or the like provided in such a detoxification facility, the air operation valve operates properly, and the drug is stably generated by opening and closing the air operation valve. Is added. However, on the other hand, when a situation occurs in which instrumentation air is not stably supplied to the air operated valve, the result is that the addition control of the chemical is not performed, so that the treatment for the acidic gas to be abated is not sufficiently performed. There is also the possibility of acid gases being released into the atmosphere.

  Therefore, the instrumentation air supply facility 1 includes a second air supply source 20 to which a second air pipe 21 is connected in order to stably supply instrumentation air to the device 50. In addition, the first air pipe 11 which is a normal air supply pipe is provided with a pressure gauge 15 and an air shutoff valve 16. According to the instrumentation air supply facility 1 having such a configuration, instrumentation air can be stably supplied even when, for example, a failure such as breakage occurs in the regular first air pipe 11.

  FIG. 3 is a flowchart for explaining a control flow for supplying instrument air to the device 50 using the instrument air supply facility 1.

(Normal operation)
As shown in the flowchart of FIG. 3, in normal operation, that is, in normal operation in which no trouble such as breakage occurs in the pipe for supplying instrument air (first air pipe 11), step S11 is performed. Then, supply of instrumentation air from the first air supply source 10 is started, and instrumentation air generated from the first air supply source 10 is supplied to the device 50 via the first air pipe 11.

  At this time, the second air supply source 20 is in a stopped state, and instrumentation air is supplied from the second air supply source 20 to the device 50 via the second air pipe 21. Absent.

  Next, as step S <b> 12, the pressure gauge 15 measures the pressure of the instrument air supplied from the first air supply source 10 and passing through the first air pipe 11. In the instrumentation air supply facility 1, a signal of the pressure value measured by the pressure gauge 15 is transmitted to the control device 17, and the pressure fluctuation of the instrumentation air is monitored.

  Next, in step S <b> 13, the control device 17 determines whether or not the pressure value has fallen below a predetermined value based on the variation in the pressure value of the instrumented air measured by the pressure gauge 15. When the control device 17 determines that the pressure value of the instrumentation air is not lower than the predetermined value (in the case of “NO”), the operation of step S13 is repeated again, and the instrumentation that is continuously supplied is determined. Measure the air pressure.

  In this way, during normal operation, instrument air is supplied from the first air supply source 10 to the device 50 through the first air pipe 11, and the pressure value of the instrument air is equal to or higher than a predetermined value. The value is maintained and supplied stably.

(Emergency operation)
Here, when the pressure value of the instrument air whose fluctuation over time is monitored falls below a predetermined value at a certain time, it passes from the first air supply source 10 through the first air pipe 11. It means that the supply amount of the instrumented air supplied is less than the consumption amount, and thus the pressure value is low. For example, a failure such as breakage occurs in the first air pipe 11, and the instrument 50 cannot stably supply a necessary amount of instrument air, or the first air supply source 10 is broken. This occurs when the required amount of instrument air cannot be generated due to the occurrence of the

  When such a failure has occurred, in step S13 described above, the control device 17 determines that the pressure value of the instrumented air measured by the pressure gauge 15 has fallen below a predetermined value (in the case of “YES”) ) Then proceed to step S14.

  In step S14, the second air supply source 20 provided in the instrumentation air supply facility 1 is operated. Next, in step S15, the supply of instrumentation air from the operated second air supply source 20 is performed. Start. Instrumented air generated from the second air supply source 20 passes through the second air pipe 21 and is supplied to the device 50.

  Subsequently, in step S16, with the start of the supply of instrument air from the second air supply source 20, the air shutoff valve 16 provided on the first air pipe 11 is closed, and the first air The flow of instrumentation air from the supply source 10 through the first air pipe 11 is cut off. In step S <b> 17, the first air supply source 10 is stopped, and the supply of instrumentation air from the first air supply source 10 is stopped.

  In step S18, following step S15, the supply of instrumentation air from the second air supply source 20 is continued, and instrumentation air is stably supplied to the device 50.

  Thus, the instrumentation air supply facility 1 is provided with the second air supply source 20. At the same time, the pressure of the instrumented air passing through the first air pipe 11 from the first air supply source 10 is always measured, and it is determined whether or not the pressure value falls below a predetermined value. . And when it detects that the pressure of the instrumentation air from the 1st air supply source 10 became low pressure, the 2nd air supply source 20 is operated, and the 2nd air supply source 20 The instrument air supply is started. According to the instrumentation air supply facility 1 and the instrumentation air supply method using the instrumentation air supply facility 1, it is always possible to prevent the device 50 from flowing back even if the piping is damaged. Instrument air can be supplied stably.

  In the above description, in step S16, the second air supply source 20 is operated in step S14, and supply of instrumented intake air from the second air supply source 20 to the device 50 is started in step S15. The air shutoff valve 16 is closed and the supply of instrumentation air from the first air supply source 10 via the first air pipe 11 is stopped.

  At this point, as shown in the flow of the dotted line from step S13 in the flowchart of FIG. 3, the air shutoff valve 16 is closed in step S16 almost simultaneously with the operation of the second air supply source 20 in step S14. An operation may be performed. By doing so, the loss of air can be minimized when the piping is significantly damaged.

  However, from the viewpoint of preventing the supply of instrumentation air to the device 50 from being completely stopped, the second air supply source 20 is operated as shown by the solid line flow in the flowchart of FIG. (Step S14), supply of instrumentation air from the second air supply source 20 is started (Step S15), and after a predetermined time, measurement from the first air supply source 10 by the air shutoff valve 16 is performed. It is preferable to shut off the supply of the charge air (step S16). In addition, since it may take time to start depending on the type of the second air supply source 20, from this point of view, the time after the start of the supply of instrument air from the second air supply source 20 is reduced. After that, it is preferable to shut off the air shutoff valve 16.

[Predetermined value of instrument air pressure]
In step S13 in the control flow described above, it is determined whether or not the pressure value of the instrumentation air passing through the first air pipe 11 from the first air supply source 10 has fallen below a predetermined value. The predetermined value of the air pressure is not particularly limited, and may be set as appropriate according to the amount of instrument air required for operation in the device 50.

  More specifically, it is preferable to set a pressure value higher than the pressure corresponding to the amount of instrument air required for the operation of the air operated valve in the device 50. For example, a value within the range of 0.4 MPaG to 0.7 MPaG, more preferably a value within the range of 0.6 MPaG to 0.8 MPaG can be set as the predetermined value.

[Behavior during recovery]
As described above, for example, when the first air pipe 11 is damaged or the like, the instrument air is switched from the second air supply source 20 and then the first air pipe 11 is switched. When the repair or replacement is completed, a recovery operation is performed to switch to the regular instrument air supply path.

  Specifically, as an operation in the restoration work, the first air supply source 10 is operated while the second air supply source 20 is in operation, and instrumentation air is supplied into the first air pipe 11. . Then, while monitoring the pressure value of the instrument air with the pressure gauge 15 provided on the first air pipe 11, it is confirmed that the pressure value of the instrument air has stabilized, and then the first air The air cutoff valve 16 provided on the pipe 11 is opened. Thereby, the supply of instrumentation air from the first air supply source 10 via the first air pipe 11 is resumed. Then, while appropriately checking the measurement value of the pressure gauge 15, the second air supply source 20 is stopped, and the supply of instrument air from the second air supply source 20 is stopped. It should be noted that after the restoration, the control flow restarted from step S12 can be executed.

  The operation in such recovery work may be performed automatically or manually by the operator.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

Example 1
Instrumentation air supply equipment 1 having the configuration shown in FIG. 1 is used for 10 alkaline aqueous solution supply valves (corresponding to “apparatus 50” in FIG. 1) provided in the acid gas abatement equipment Supplied. This alkaline aqueous solution supply valve is for supplying caustic soda and magnesium hydroxide used to remove acid gas generated by dry copper smelting, and is an automatic air operated valve that operates with instrument air. It is.

  In the instrument air supply facility 1, instrument air is supplied from the first air supply source 10 to the alkaline aqueous solution supply valve via the first air pipe 11 during normal operation. On the other hand, in the control device 17 provided in the instrumentation air supply facility 1, a pressure value higher than the pressure value corresponding to the minimum instrumentation air amount necessary for the operation of the alkaline aqueous solution supply valve is recorded as the “reference pressure value”. The pressure of instrumentation air passing through the first air pipe 11 from the first air supply source 10 was monitored over time.

  Then, when the pressure value of the instrument air in the first air pipe 11 fluctuates and falls below the recorded reference pressure value, the second air supply source 20 is activated and the second air The supply of instrument air from the supply source 20 via the second air pipe 21 was started, while the air shutoff valve 16 provided on the first air pipe 11 was operated to close.

  When operation was performed over a predetermined period while performing such operation control, the normal detoxification process proceeded without any abnormality, and the instrumental air was continuously supplied to each alkaline aqueous solution supply automatic valve and It was confirmed that the product was stably supplied.

DESCRIPTION OF SYMBOLS 1 Instrumentation air supply equipment 10 1st air supply source 11 1st air piping 15 Pressure gauge 16 Air shut-off valve 17 Control apparatus 20 2nd air supply source 21 2nd air piping 30 Instrumentation air storage tank (air Receiver tank)
31a, 31b Shut-off valve 50 Equipment (instrumentation equipment)

Claims (6)

An instrument air supply facility for supplying instrument air to an instrument,
A first air supply;
A first air pipe for connecting the first air supply source and the device, and for supplying instrument air from the first air supply source to the device;
A second air supply source;
A second air pipe connected to the first air pipe at a predetermined position and for supplying instrument air from the second air supply source to the device;
In the first air pipe,
A pressure gauge for measuring the pressure of instrument air supplied from the first air supply source;
An air shut-off valve that is located upstream of a connection point with the second air pipe and shuts off the supply of instrument air from the first air supply source;
When the pressure of instrument air in the first air pipe measured by the pressure gauge falls below a predetermined value, the supply of instrument air from the first air supply source is shut off by the air shut-off valve. And the instrument air is supplied to the device from the second air supply source via the second air pipe when the second air supply source is operated. Supply equipment. A predetermined value of the pressure of the instrumentation air at which the supply of instrumentation air from the first air supply source is shut off by the air shutoff valve and the second air supply source operates is 0.4 MPaG to The instrumentation air supply facility according to claim 1, wherein the instrumentation air supply facility has a value within a range of 0.7 MPaG. The instrumentation air supply facility according to claim 1 or 2, wherein the first air pipe is provided with an instrumentation air storage tank at a position downstream of a place where the pressure gauge is provided. The instrument air supply facility according to any one of claims 1 to 3, wherein an instrument air storage tank is provided in the second air pipe. An instrument air supply method for supplying instrument air to the instrument by an instrument air supply facility connected to the instrument,
The instrument air supply equipment
A first air supply;
A first air pipe for connecting the first air supply source and the device, and for supplying instrument air from the first air supply source to the device;
A second air supply source;
A second air pipe connected to the first air pipe at a predetermined position and for supplying instrument air from the second air supply source to the device;
In the first air pipe,
A pressure gauge for measuring the pressure of instrument air supplied from the first air supply source;
An air shut-off valve that is located upstream from the connection point with the second air pipe and shuts off the supply of instrument air from the first air supply source; and
During normal operation,
Stopping the second air supply source, operating the first air supply source, and supplying instrument air from the first air supply source to the device via the first air pipe;
In the case where the pressure of instrumented air in the first air pipe measured by the pressure gauge is below a predetermined value,
The air shutoff valve shuts off the supply of instrumentation air from the first air supply source, operates the second air supply source, and sends instrumentation air from the second air supply source to the first air supply source. An instrumentation air supply method, comprising: passing through the air pipe of 2 and supplying the instrument to the equipment. In the case where the pressure of instrumented air in the first air pipe measured by the pressure gauge is below a predetermined value,
After the second air supply source is operated and supply of instrumentation air from the second air supply source is started, a predetermined time is passed, and then the air shut-off valve causes the first air supply source to The instrumentation air supply method according to claim 5, wherein the instrumentation air supply is cut off.

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