JPH09264822A - Sampling apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sampling apparatus by which a sampling amount can be measured without using a flowmeter. SOLUTION: A first optical fiber sensor (a first sensor) 32 which detects that a plunger is moved to a discharge position (an upper dead-point position) and a second optical fiber sensor (a second sensor) 33 which detects that a plunger for a constant flow pump 4 is moved to a suction position (a lower dead-point position) are installed at the constant flow pump 4 at a sampling apparatus 31. In the sampling apparatus 31, sampling valves 8, 9 are changed over on the basis of detection signals which are output from the optical fiber sensors 32, 33, and an oil liquid can be sampled into sampling containers 22, 23, and a microfilter and a volumetric flowmeter which are required in conventional cases can be eliminated. As a result, the maintenance of the microfilter and the volumetric flowmeter is not required.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sampling device, and more particularly to a sampling device for sampling a fixed amount of liquid by starting a pump.

[0002]

2. Description of the Related Art For example, in an essential oil facility for refining oil liquid such as petroleum, a large amount of refined oil liquid is fed to a tanker or a storage tank via a main pipe line. In a facility that handles a large amount of oil liquid, it is important to accurately control not only the amount of oil liquid but also the quality.

Therefore, a sampling device for sampling a fixed amount of oil liquid is provided in the middle of the feeding pipe, and the oil liquid sampled by this device is analyzed to analyze the specific gravity, sulfur content, salt content, water content, etc. Inspection is performed for each item. As a sampling device of this type, for example, as shown in FIG. 7, a ball valve 2, a strainer 3, a metering pump from a upstream side to a pipeline 1 branched from a main pipeline (not shown) to which oil liquid is fed. 4, differential pressure valve 5, micro filter 6, positive displacement flow meter 7,
Collection valves 8 and 9, check valves 10, which are air-driven three-way valves,
A ball valve 11 is provided. Further, the downstream end of the pipe 1 is connected to the main pipe, and the oil circulates in the pipe 1 when the oil liquid is not sampled.

The solenoid directional control valve 1 is installed in the drive unit of the sampling valves 8 and 9.
The compressed air from the air source 14 is supplied by switching between 2 and 13. In addition, the electromagnetic switching valves 12, 13 and the air source 14
A regulator 16, a filter 17, and a ball valve 18 are arranged in a pipe line 15 that communicates with.

The metering pump 4 is a plunger type pump which is constructed to suck and discharge a fixed amount of oil liquid while the plunger reciprocates once. The pump drive unit 19 that drives the plunger of the metering pump 4 is drive-controlled by a control signal output from the pump control panel 20. Then, the pump control panel 20 controls the drive of the pump drive unit 19 according to the control signal output from the device control panel 21. In addition, the flow rate pulse output from the positive displacement flow meter 7 is transmitted to the device control panel 2
1 and monitor the electromagnetic switching valves 12 and 13 on the equipment control panel 21.
It is excited and switched by the signal output from.

When the sampling valves 8 and 9 are switched by the air signal from the electromagnetic switching valves 12 and 13, the metering pump 4 is operated.
The oil liquid pressure-fed from is discharged to the collection containers 22 and 23. The device control panel 21 automatically calculates operating conditions according to preset sampling data, and monitors the operating timing of the metering pump 4 and the flow rate pulse output from the positive displacement flow meter 7.

The sampling method for collecting the oil liquid includes a sampling method called "time synchronization type" used when the flow rate is constant and a "flow rate response type" used when the flow rate varies. There is a collection method called. In the time-synchronized sampling method, the sampling valves 8 and 9 are switched at predetermined time intervals to collect the oil liquid in the sampling containers 22 and 23. Also,
In the flow rate response type sampling method, the sampling frequency is calculated from the total amount of the oil liquid flowing in the main pipeline, and when the flow rate reaches the integrated value to be sampled, the sampling valves 8 and 9 are switched to collect the sampling container 22,
Collect the oil solution in 23.

[0008]

However, in the conventional sampling device having the above-mentioned structure, the microfilter 6 is arranged upstream of the positive displacement flowmeter 7 for removing foreign matters contained in crude oil. However, since it is necessary to collect the foreign matter contained in the crude oil as a component, it is not possible to use a fine mesh of the micro filter 6, and the foreign matter adheres to the rotating part of the positive displacement flow meter 7 to rotate the rotor. There is a problem of causing defects. Therefore, conventionally, the service life of the positive displacement type flow meter 7 is shortened, and the positive displacement type flow meter 7 must be frequently maintained.

Although it is conceivable to use a flow meter having no rotating part such as a Coriolis mass flow meter instead of the positive displacement flow meter 7, it is costly and not practical. Then, this invention aims at providing the sampling device which solved the said subject.

[0010]

In order to solve the above problems, the present invention has the following features. Claim 1
In the invention, a metering pump that sucks and discharges the liquid from a pipe through which the liquid is fed, a drive unit that reciprocally drives a plunger of the metering pump, and a liquid that is discharged from the metering pump is supplied to a sampling container. In a sampling device having a sampling valve for controlling the operating position of the plunger of the metering pump, a counter for counting the pulses output from the sensor, and a count value of the counter reaching a predetermined value. And a control means for switching the sampling valve to terminate the sampling.

Therefore, according to the first aspect of the present invention, when the count value of the pulse from the sensor for detecting the operating position of the plunger of the metering pump reaches a predetermined value, the sampling valve is switched to terminate the sampling. A certain amount of liquid can be collected in the collection container based on the number of times the plunger of the pump is operated.

According to the second aspect of the present invention, a metering pump that sucks and discharges the liquid from a conduit through which the liquid is fed, a drive unit that reciprocally drives a plunger of the metering pump, and the metering pump discharges the liquid. In a sampling device having a sampling valve that supplies a liquid to a sampling container, a first sensor that detects that the plunger of the metering pump has moved to a discharge position, and the plunger of the metering pump has moved to a suction position. And a counter for counting the pulses output from the first sensor, and when the pulse from the second sensor is received, the sampling valve is switched to start sampling, Control means for switching the sampling valve and ending sampling when the count value of the counter reaches a predetermined value and then receives a pulse from the second sensor. And it is characterized in and.

Therefore, according to the second aspect of the invention, by receiving the pulse from the second sensor, the sampling valve is switched to start sampling, and the count value of the pulse output from the first sensor is predetermined. When a pulse from the second sensor is received next time, the sampling valve is switched and the sampling is completed, so that a certain amount of liquid can be sampled in the sampling container according to the number of times of operation of the plunger of the metering pump. it can.

Further, the pulse from the second sensor is used as a switching timing signal of the sampling valve, and the pulse output from the first sensor is counted as a flow rate signal, thereby accurately measuring a certain amount of liquid. You can

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the sampling device according to the present invention. In FIG. 1, the same parts as those shown in FIG. 5 are designated by the same reference numerals and the description thereof will be omitted.

The sampling device 31 is, for example, an oil liquid for loading an oil liquid refined in a refinery into a tanker or a tank truck (both not shown) or an oil liquid unloaded from the tanker or the tank truck of the metering pump 4. It is collected by reciprocating motion. The metering pump 4 includes a first optical fiber sensor (first sensor) 32 for detecting that the plunger has moved to a discharge position (top dead center position), and a plunger for the metering pump 4 having a suction position (bottom dead center). A second optical fiber sensor (second sensor) 33 for detecting the movement to the point position) is provided.

In the sampling device 31, the sampling valves 8 and 9 can be switched based on the detection signals output from the optical fiber sensors 32 and 33 to collect the oil liquid in the sampling containers 22 and 23, as described later. The microfilter 6 and the volumetric flowmeter 7 which have been conventionally required can be eliminated. Therefore, maintenance of the microfilter 6 and the positive displacement flowmeter 7 can be omitted.

FIG. 2 is an enlarged view of the metering pump 4. The optical fiber sensors 32 and 33 are provided in the pump drive unit 19.
The moving position of the plunger 34 of the metering pump 4 driven by is detected in a non-contact manner, and is supported by a bracket 4a fixed to the metering pump 4. Then, when the light emitted from the ends is reflected by the plunger 34 and received, the optical fiber sensors 32 and 33 output an optical signal to the device control panel 21 as a detection signal. Although these optical fiber sensors 32 and 33 are used in explosion-proof locations,
Since it is not necessary to use an explosion-proof structure, it is possible to prevent the sensor itself from increasing in size, even when collecting a liquid having flammability, and to provide a compact structure.

The optical fiber sensor 32 is a pump drive unit 19.
The plunger 34 driven by the optical fiber sensor 3 is mounted at a position for detecting the displacement to the top dead center position.
3 is attached to a position for detecting the displacement of the plunger 34 to the bottom dead center position. In addition, the signal output from one optical fiber sensor 32 is the optical fiber 32a.
Is transmitted to the device control panel 21 and used as a signal for flow rate monitoring. The signal output from the other optical fiber sensor 33 is transmitted to the device control panel 21 through the optical fiber 33a and used as a signal for valve switching timing monitoring.

Here, a monitoring method for monitoring the operation of the metering pump 4 of the sampling device 31 will be described. In this embodiment, since the plunger type metering pump 4 is used, the discharge amount per stroke of the plunger 34 of the metering pump 4 is constant. Therefore, the device control board 21 monitors the optical signals from the optical fiber sensors 32 and 33 as a fixed amount of unit pulses discharged in one stroke of the plunger 34 of the metering pump 4, that is, a flow rate pulse. Then, on the device control panel 21, as will be described later, the optical fiber sensor 3
A control program is stored for counting the optical signals from 2, 33 and controlling the switching of electromagnetic switching valves 12, 13 that drive the flow rate calculation and sampling valves 8, 9 and the drive control of the metering pump 4.

FIG. 3 is a flow chart for explaining the first control method executed by the equipment control panel 21, and FIG. 4 is a timing chart corresponding to the processing of FIG. The device control panel 21 is step S1 (hereinafter “step” is omitted).
Set collection conditions with and start the system. The sampling conditions include a "time synchronization mode" used when the flow rate is constant and a "flow rate response mode" used when the flow rate changes. That is, in S1, a "time synchronization mode" in which sampling is performed every predetermined time, or a "flow rate response mode" in which sampling is performed when the flow rate of the main pipeline reaches a predetermined flow rate
Or set.

In the next S2, the operating timing of the sampling device is monitored based on the sampling conditions set in S1 and the operating timing (every predetermined time or every predetermined flow rate).
When it becomes, it progresses to S3, the pump drive part 19 is started, and the plunger 34 of the metering pump 4 is reciprocally driven. The reciprocating movement of the plunger 34 is caused by the optical fiber sensor 3
2,33 detected.

In next step S4, the collection valves 8 and 9 are set in a circulating state, and the oil liquid pressure-fed from the metering pump 4 is fed through the pipe line 1 and is returned to the main pipe line (not shown). Then, the previous oil liquid remaining in the pipe 1 is purged. In the next S5, the time for purging the conduit 1 is measured, and when the preset purge time t (see FIG. 4 (A)) has elapsed, the process proceeds to S6, and the liquid is fed through the conduit 1. Set the start of oil sampling. That is, in S7, the electromagnetic switching valve 12 that drives the sampling valve 8 is excited and switched. Therefore, the sampling valve 8 switches to the sampling state, and the metering pump 4
The oil liquid pressure-fed from is collected in the collection container 22.

At S8, the plunger 34 of the metering pump 4 is
When the pulse of the optical signal from the optical fiber sensor 32 output according to the number of round trips is received, the received pulse is counted (see FIG. 4B). And metering pump 4
Since the flow rate discharged from the metering pump 4 can be obtained by multiplying the discharge amount when the plunger 34 reciprocates once by the pulse count value, the pulse count value is set to the preset sampling amount in S9. It is determined whether or not the corresponding target value n has been reached.

When the pulse count value reaches the target value n in S9, it is judged that a predetermined sampling amount has been collected in the sampling container 22, the process proceeds to S10, and the electromagnetic switching valve 12 that drives the sampling valve 8 is set. Demagnetize and return the sampling valve 8 to the circulating state. Thereafter, in S11, the metering pump 4 is stopped (see FIG. 4C). Then, in S12, the collection into the collection container 22 is completed.

In this way, since a fixed amount of oil liquid can be collected in the collection container 22, there is no need to install a flow meter in the pipe line 1, and maintenance work relating to the flow meter can be omitted for maintenance and inspection work. It can be simplified and the maintenance time can be shortened. In the next S13, it is determined whether or not the number of times of sampling or the amount of sampling has reached the set value. S
In S13, when the number of times of sampling or the amount of sampling does not reach the set value, the process returns to S2 and the processes of S2 to S13 are repeated.

If the number of times of sampling or the amount of sampling reaches the set value in S13, the process proceeds to S14 and it is determined whether or not there is a sampling setting for the second container. In S14, if there is a sampling setting for the second container, the process returns to S2, and the processes of S2 to S13 are repeated to perform sampling in the sampling container 23 that is the second container.

Further, in S14, when there is no setting for sampling in the second container, there is no need to perform sampling in the sampling container 23, so the processing of this time is ended. Also,
In the case of the control method shown in FIG. 3, it is only necessary to be able to count the number of reciprocations of the plunger 34 of the metering pump 4, so that only one of the two optical fiber sensors 32 and 33 is required.

FIG. 5 is a flow chart for explaining the second control method executed by the equipment control panel 21, and FIG. 6 is a timing chart corresponding to the processing of FIG. In FIG. 5, the processing of S21 to S26 is the same as the processing of S1 to S6 described above, and thus the description thereof is omitted.

When the sampling start is set in S26, the equipment control panel 21 proceeds to S27, where the second optical fiber sensor 3
Receive the pulse output from 3. Then, using the pulse of the second optical fiber sensor 33 as a trigger, the electromagnetic switching valve 12 that drives the sampling valve 8 is excited and switched in S28 (see FIG. 6C). Therefore, the sampling valve 8 is switched to the sampling state, and the oil liquid pumped from the metering pump 4 is sampled in the sampling container 22.

In the next S29, the number of pulses output from the first optical fiber sensor 32 according to the number of reciprocations of the plunger 34 of the metering pump 4 is counted (see FIG. 6B).
I do. Then, in S30, it is determined whether or not the pulse count value has reached the target value n corresponding to the sampling amount set in S21.

When the pulse count value reaches the target value n in S30, it is judged that a predetermined sampling amount has been collected in the sampling container 22, the process proceeds to S31, and the second optical fiber sensor 33 outputs. Receive pulse. When the pulse output from the second optical fiber sensor 33 is received, the electromagnetic switching valve 12 that drives the sampling valve 8 is demagnetized by using this as a trigger to return the sampling valve 8 to the circulation state. After that, in S33, the metering pump 4 is stopped (see FIG. 6D). Then, in S34, the collection into the collection container 22 is completed. In this way, a fixed amount of oil liquid can be accurately collected in the collection container 22.

In the next step S35, it is determined whether or not the number of times of sampling or the amount of sampling has reached a set value. In S35,
When the number of times of sampling or the amount of sampling does not reach the set value, the process returns to S22 and the processes of S22 to S35 are repeated. If the number of times of sampling or the amount of sampling reaches the set value in S35, the process proceeds to S36, and it is determined whether or not there is a sampling setting for the second container. This S36
In the case where there is a sampling setting in the second container, the process returns to S22, and the processes of S22 to S35 are repeated to perform sampling in the sampling container 23 which is the second container.

If there is no setting for sampling in the second container in S36, there is no need to perform sampling in the sampling container 23, so the processing of this time is ended. Also,
In the second control method, when the start of sampling is set and the pulse from the second optical fiber sensor 33 is received, the sampling in the sampling container 22 is started as a trigger, and the first
The pulses from the optical fiber sensor 32 of are counted.
Then, when the pulse count value reaches the target value n and then the pulse from the second optical fiber sensor 33 is received, the sampling valves 8 and 9 are switched to the circulation state to end the sampling. The amount corresponding to the value can be accurately collected, and the accuracy of the collected amount can be improved.

Although the oil liquid is collected in the above embodiment, the present invention is not limited to this, and it is needless to say that the present invention can be applied to the collection of liquid chemicals other than oil liquid or foods.

[0036]

As described above, according to the first aspect of the present invention,
When the count value of the pulse from the sensor that detects the operating position of the plunger of the metering pump reaches a specified value, the sampling valve is switched to end sampling, so a fixed amount of liquid is collected from the number of times the plunger of the metering pump operates. Can be collected. Also, since the pulse output from the sensor can be used in place of the flow rate signal to collect a fixed amount of liquid, the flow meter that was conventionally required can be eliminated,
Maintenance of the flow meter can be eliminated.

According to the second aspect of the present invention, by receiving the pulse from the second sensor, the sampling valve is switched to start sampling, and the count value of the pulse output from the first sensor is predetermined. When a pulse from the second sensor is received next time, the sampling valve is switched and the sampling is completed, so that a certain amount of liquid can be sampled in the sampling container according to the number of times of operation of the plunger of the metering pump. it can.

Further, the pulse from the second sensor is used as a switching timing signal for the sampling valve, and the pulse output from the first sensor is counted as a flow rate signal to accurately measure a certain amount of liquid. Since it is possible to eliminate the flowmeter that was conventionally required,
Maintenance of the flow meter can be eliminated.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of a sampling device according to the present invention.

FIG. 2 is an enlarged view of a metering pump.

FIG. 3 is a flowchart for explaining a first control method executed by the device control panel.

FIG. 4 is a timing chart corresponding to the processing of FIG.

FIG. 5 is a flowchart for explaining a second control method executed by the device control panel.

6 is a timing chart corresponding to the processing of FIG.

FIG. 7 is a schematic configuration diagram for explaining the configuration of a conventional sampling device.

[Explanation of symbols]

 1 Pipeline 4 Metering Pump 8, 9 Sampling Valve 12, 13 Electromagnetic Switching Valve 19 Pump Drive Unit 20 Pump Control Panel 21 Equipment Control Panel 22, 23 Sampling Container 31 Sampling Device 32 First Optical Fiber Sensor (First Sensor) 33 second optical fiber sensor (second sensor) 34 plunger

Claims (2)

[Claims] 1. A metering pump that sucks and discharges liquid from a pipe through which the liquid is fed, a drive unit that reciprocally drives a plunger of the metering pump, and a liquid that is discharged from the metering pump into a collection container. A sampling device having a sampling valve for supplying, a sensor for detecting an operating position of a plunger of the metering pump, a counter for counting pulses output from the sensor, and a count value of the counter being a predetermined value. And a control means for switching the sampling valve to terminate the sampling. 2. A metering pump that sucks and discharges the liquid from a pipe through which the liquid is fed, a drive unit that reciprocally drives a plunger of the metering pump, and a liquid that is discharged from the metering pump into a collection container. A sampling device having a supply valve for supplying, a first sensor for detecting that the plunger of the metering pump has moved to a discharge position, and a second sensor for detecting that the plunger of the metering pump has moved to a suction position. Sensor, a counter for counting the pulses output from the first sensor, and when the pulse from the second sensor is received, the sampling valve is switched to start sampling, and the count value of the counter is predetermined. And a control means for switching the sampling valve to terminate the sampling when the pulse from the second sensor is received next time. Apparatus.