JPS6410674B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a pump safety monitoring device for monitoring abnormal operation of a pump for transporting flammable liquids, such as a pump for transporting and pressurizing flammable liquids such as petroleum. A large number of oil pumps are installed at oil bases that handle large amounts of oil, such as refineries and oil storage plants.These types of pumps are driven by various drive devices, generally motors, and operate continuously. Often. Therefore, if an accident occurs during operation, not only will transportation of oil be interrupted and production be seriously hindered, but there is also the risk of a major accident. For this reason, pump accidents need to be detected early, and oil terminals have traditionally carried out the following as part of their operational safety measures:
The operating status of each pump was checked by security personnel, but the monitoring work by security personnel not only took time and required a large amount of effort, but there were problems such as there was a high risk of leaks in the checks. . The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a system for transporting flammable liquids that can be easily attached to an existing pump, and that can be easily and reliably monitored. The purpose of the present invention is to provide a safety monitoring device for pumps for use. The present invention will be described below based on an illustrated embodiment. The main components of the monitor in this example consist of vibration, liquid leakage, and temperature detection elements installed at key points on the pump, and further installed on the ground at a safe flammability distance from the pump. It is formed by an alarm generating circuit and a display unit housed in a monitoring panel, and the arrangement thereof will be described in detail below with reference to FIGS. 1 and 2. First, the oil pump 1 equipped with a monitor is
Upper and lower casings 2 and 3, and the same casing 2,
The rotating shaft 4 is supported by bearings 5 and 6 integrally formed at both inner and outer ends of the lower casing 3, and is connected to a motor 8 via a coupling 7. Driven. The thus transferred oil enters the casings 2 and 3 through the suction pipe 9, and after being pressurized is discharged to the outside through the discharge pipe 10. Here, the mounting manner of each sensing element will be explained for each element. (a) Vibration detection element 11 This is screwed to the stepped surface of the casing 3 at the middle part of the inner bearing part 5 on the front side in FIG. A piezoelectric element is used in the vibration detection element 11, and when vibration of the pump is applied to the piezoelectric element, a voltage proportional to the magnitude of the vibration is generated. In this example, the characteristic is vibration acceleration (g)
It exhibits an electromotive voltage of 44 mV/g per unit,
A signal is set to generate an alarm when the vibration acceleration (g) exceeds 2±0.5g, and this setting value is arbitrarily selected according to the vibration characteristics of the pump. In this embodiment, a piezoelectric element is used as the vibration detection element 11, but other elements such as a strain cage whose resistance value changes with vibration may also be used. (b) Liquid leak detection element 12 It is attached to the side wall of the recess inside the stepped surface of the lower casing 3, and its sensing part faces close to the side of the mechanically sealed bearing. As shown in FIG. 3, the liquid leak detection element 12 that detects the leakage of flammable liquid uses an oil detection element as described later in its sensing section 13. If the mechanical seal is used in an exposed state, it is likely to malfunction due to the adhesion of oil droplets that leak slightly due to the structure of the mechanical seal, so the protective pipe 14 held in the cap nut is This covers the periphery of the sensing section 13. That is, when there is no abnormality in the pump 1, there is very little oil leakage, and almost no oil accumulates in the recessed part inside the casing 3 due to natural drying, so that the oil never reaches the sensing part 13. In the unlikely event that the pump 1 malfunctions and a large amount of oil leaks, the sensing part 13
resistance value changes rapidly. Therefore, if the alarm generating circuit 28 shown in FIG. 8, which will be described later, detects this, the abnormality can be immediately determined and an alarm can be issued. FIG. 4 shows an example of the sensing section 13.
In the figure, 41 is a base made of an insulator or a resistor, and 42 is an oil detection resistor, for example, silicone resin or silicone rubber and conductive powder such as graphite or metal powder are mixed in a ratio of 20 to 30:1. ,
Use a mixture that has been thoroughly kneaded with an appropriate amount of toluene or the like. This is formed by coating the outer periphery of the base 41. Reference numerals 43 denote electrodes provided at both ends of the base 41, and lead wires 44 are attached to each of these electrodes. Reference numeral 45 denotes an oil detection coating, which is provided to cover the oil detection resistor 42, the electrode 43, and the base of the lead wire 44.
The material for the oil detection coating 45 is water-repellent, and exhibits swelling, solubility, and permeability to oils, organic solvents, etc., such as silicone rubber, various synthetic rubbers, polypropylene, polyethylene, etc. . When oil comes into contact with the oil detection resistor 42, the oil detection resistor 42 rapidly swells, so that the electrical resistance value between both electrodes 43 changes greatly. Furthermore, since the resistance value of the oil detection resistor 42 becomes large almost instantaneously after coming into contact with oil, an oil detection coating 45 is provided for the purpose of preventing malfunction. Therefore, the characteristic of the liquid leak detection element 12 is that its resistance value changes in response to the degree of swelling caused by the adhesion of oil or organic solvent vapor, and in this embodiment, when 0.5 cc or more of oil has adhered It is set so that a signal is generated. Of course, this set value can be arbitrarily selected according to the characteristics of the pump. (c) Temperature sensing elements 15, 16 Among the two temperature sensing elements 15, 16, one temperature sensing element 15 is installed near the center of the upper surface of the casing 2, and the other temperature sensing element 16 is It is attached to the side surface of the outer bearing part 6. In each of these temperature sensing elements 15 and 16, as shown in FIG. The anode gate was set to open at Of course, the temperature detection elements 15 and 16 serving as temperature sensors may be thermocouples or other types other than those described above, and the set values may be arbitrarily selected. Next, each of these sensing elements 11, 12, 15,
Wiring for 16 is for each shielded cable 17~
21, and are concentrated in a connection housing 22, which is erected near the side of the coupling 7, as described below. (a) Temperature detection element 15 Cable 18 → Cable 17 (b) Vibration detection element 11 and liquid leakage detection element 1
2 Cable 20 → Cable 19 → Cable 17 (c) Temperature detection element 16 Cable 21 → Cable 19 → Cable 17 Also, at a position near the motor 8 and a safe distance away from the pump 1, that is, an electric spark ignites the pump 1. A monitoring panel 23 is erected in a place where there is no risk of damage, and the monitoring panel 23 and the connection case 22 are electrically connected by an underground cable 24 through which a large number of conductive wires are inserted. Incidentally, inside the connection casing 22, a lead connection board 25 for connecting the conductors of the cable 24 and the cables 17 to 21, and a circuit CI for converting the impedance of the vibration detection element as described later are installed. Also, inside the monitoring panel 23, there is an intrinsically safe keeper 27 (Zener barrier) consisting of a fuse and a Zener diode, and an alarm generating circuit 2.
8, and a display unit 30 are built in. When the cover on one side of the monitoring panel 23 is opened, the display surface of the display unit 30 (Fig. 8), that is, the pilot lamp PL, temperature, flammable liquid leakage, vibration, etc. The board surface to which another alarm indicator lamp LED, buzzer B, etc. are attached can be seen through the display window. This alarm indicator lamp LED
and buzzer B constitute an alarm. Here, the electrical operation of each part of the above-mentioned monitor device will be sequentially explained with reference to the circuit diagrams shown in FIGS. 6 to 10. FIG. 6 shows the electrical connection state of each sensing element. In this FIG. 6, the vibration detection element 11
If the output is high impedance and is connected directly to the alarm generation circuit 28 through the connection board 25, it will often pick up noise, so it is converted to low impedance through the impedance converter CI and output. An example of the circuit of the impedance converter CI is shown in FIG. 7. In Figure 7, C ₁ to C ₁₀ are capacitors, R ₁ to _{R 15} are resistors, VR is a variable resistor, FET is a field effect transistor, TR is a transistor, D ₁ and D ₂ are diodes, and PUT is a programmable unit. There is a juncture transistor. When the output of the vibration detection element 11 applied to one end of the capacitor _C1 exceeds a certain value, the field effect transistor FET turns on, this output is amplified by the transistor TR, the programmable union transistor PUT becomes conductive, and the resistor _R15
It is converted to an impedance determined by Again in FIG. 6, the temperature sensing element is 15,1
This shows a case where three pieces, 6 and 16', are connected in parallel.
C and R are a capacitor and a resistor connected in parallel between the gate and anode, the capacitor C is for making it strong against noise, and the resistor R is for controlling the operation of the thermal thyristor SCR by changing its value. This is for changing the temperature setting. And capacitor C and resistor R are heat sensitive thyristors
It can be housed in the same case as the SCR and integrated. In this way, the temperature sensing elements 15, 16, 16' using the heat-sensitive thyristor SCR have both a temperature sensing function and a thyristor function, so that the circuit configuration is extremely simplified. In addition, FIG. 6 shows liquid leakage detection elements 12, 12'.
This shows the case where two are connected in parallel. As described above, each sensing element 11 in FIG.
15, 16, 16', 12, and 12' detect and output vibration, temperature, and leakage of flammable liquid. In addition,
In FIG. 6, W indicates a lead wire, and S indicates a shield portion. The output circuit 31 from each of these sensing elements is
As shown in FIG. 8, it is connected to an alarm generating circuit 28 through an intrinsically safe holder 27 (Zener barrier). This intrinsically safe keeper 27 has the function of preventing electrical energy that could become an ignition source from being input into the side of each detection element when the alarm generation circuit 28 is detected. All pumps and motors must have an explosion-proof structure, and each sensor attached to them, including their lead wires, must have an explosion-proof structure to make them inherently safe. Next, FIG. 9 shows the alarm generation circuit 28 in FIG.
An example is shown below. In this figure, Bt, Tt, and Gt are all input terminals, and the output from each sensing element that passes through the intrinsic safety barrier is converted to a DC output level and applied. ICa, ICb, and ICc are comparators, LED ₁ to _{LED 3} are light emitting diodes incorporated in the display unit 30 in Fig. 8, PC is a photocoupler, Q ₁ to _{Q 3} are transistors, and symbols for other resistors and diodes are omitted. did. When a voltage higher than the specified value is applied to any of the input terminals Bt, Tt, and Gt, an output is output from the comparator ICa to ICc to which it is applied, and one of the transistors Q ₁ to _{Q 3} is output. operated light emitting diode
One of LED ₁ to LED ₃ is activated to notify that there is an abnormality, and at the same time, the photocoupler PC is activated and conduction is established between the output terminals Ot. Therefore, if the output terminal O is used as a switching element to operate a relay or other device, the alarm B in Fig. 8 can be activated.
It can actuate the motor or trip the motor or disconnector (not shown). FIG. 10 is another example showing the electrical connection state of each sensing element, and the difference from FIG. 6 is that the lead wires of temperature sensing elements T ₁ to T ₃ and liquid sensing elements G ₁ and G ₂ are The point is that each W is drawn out as a shield S separately. As described above, if an abnormality is detected in any of the element signals, an alarm signal is generated and applied to the display unit 30, which causes the buzzer B to sound and respond to the abnormal element. The indicator lamp LED lights up, allowing security personnel to immediately proceed to first aid. Furthermore, since the alarm display is irreversible, there will be no check errors even in the event of a short-term abnormality.In addition, although not shown in the figure, the operation switch for the drive source such as a motor can be automatically turned off along with the alarm. If you do so, you can immediately stop the motor. By the way, the circuit shown in FIG. 6 is provided with a circuit that can accommodate up to two liquid leak detection elements and three temperature detection elements, but these can be easily increased or decreased along with the detection points of the pump 1 as necessary. be able to. Further, the attachment location of each detection element can be set at an appropriate location other than the above. In addition, the location of the display unit 30 can be freely selected away from the alarm generation circuit 28. For example, if it is installed in a dedicated monitoring room such as a control room, the work efficiency of security personnel can be further improved. This makes it possible to make it easier. As described above, according to the pump safety monitoring device according to the present invention, a vibration detection element and a temperature detection element are attached to at least one of the bearing part and the casing of a flammable liquid transport pump, and the mechanical A liquid leakage detection element for detecting the leakage of flammable liquid is installed on the outside air side of the seal, and an alarm is installed to issue an alarm when at least one of the outputs of each of the detection elements exceeds the alarm set value. Since it is possible to simultaneously monitor the three elements of a pump for transporting flammable liquids: abnormal vibration, temperature rise, and oil leakage from the mechanical seal, monitoring of abnormal operation of the pump is easy and reliable, and this type of pump can be monitored easily and reliably. The safety of oil refineries, oil storage bases, etc. where pumps are installed can be easily and reliably ensured. Further, each of the detection elements has its respective output circuit,
Once integrated in a connection board built into one connection case, an alarm generation circuit is connected to the output circuit from this connection board, and the alarm is attached to this alarm generation circuit, so the handling and handling of the alarm is easy. This has the effect of facilitating maintenance and improving the economic efficiency and practicality of the pump safety monitoring device. Further, in the present invention, as shown in claim 5, each output circuit of the vibration sensing element, temperature sensing element, and liquid leakage sensing element is connected to the alarm generation circuit through an intrinsically safe keeper. By providing the pump with an intrinsically safe explosion-proof structure, the safety and reliability of the pump safety monitoring device can be further improved, and the safety of the oil base or the like where the pump is installed can be ensured.

[Brief explanation of the drawing]

FIG. 1 is a side view of the mechanical configuration of a pump safety monitoring device showing one embodiment of the present invention, FIG. 2 is a plan view of the same, and FIG. 3 is a front sectional view showing how a liquid leak detection element is equipped. Figure 4 is an explanatory diagram of the sensing section in Figure 3;
Figure 5 is a front cross-sectional view of the equipment of the temperature sensing element;
The figure shows the electrical connection circuit diagram of each detection element, and Figure 7 shows the electrical connection circuit diagram of each detection element.
8 is a block diagram of the electrical configuration of the present invention, FIG. 9 is a circuit diagram of the alarm generation circuit of FIG. 8, and FIG. 10 is an electrical connection circuit diagram of FIG. 6. It is a figure showing other examples. 1... Pump, 2, 3... Casing, 5, 6
... Bearing section, 11 ... Vibration detection element, 12 ... Liquid leakage detection element, 15, 16 ... Temperature detection element,
17-21... Shield cable, 22... Connection box, 23... Monitoring panel, 25... Connection board, 27...
Intrinsically safe barrier, 28...Alarm generating circuit, 30...
...display unit, 31...output circuit.

Claims (1)

[Scope of Claims] 1. A pump for transporting flammable liquids, comprising: a vibration detection element 11 and temperature detection elements 15, 16 attached to at least one of a bearing portion and a casing of the pump; and a mechanical seal portion of the pump. A liquid leak detection element 12 installed on the outside air side to detect leakage of flammable liquid, and a connection board 25 that temporarily consolidates the output circuits of the respective detection elements.
one connection casing 22 in which is housed, and the connection board 2
An alarm generation circuit 28 connected to the output circuit 31 of each detection element from 5 and attached to this alarm generation circuit 28 generates an alarm when at least one of the outputs of each of the detection elements exceeds the alarm setting value. A pump safety monitoring device comprising: an alarm that emits an alarm; 2. The pump safety monitoring device according to claim 1, wherein the temperature detection element is a heat-sensitive thyristor. 3. The pump safety monitoring device according to claim 1, wherein the liquid leak detection element is an oil detection resistor whose electrical resistance becomes high upon contact with a flammable liquid. 4. The pump safety monitoring device according to claim 1, wherein the alarm is an alarm indicator lamp, a buzzer, or both an alarm indicator lamp and a buzzer. 5. In a pump for transporting flammable liquid, a vibration detection element and a temperature detection element are attached to at least one of the bearing and the casing of the pump, and a vibration detection element and a temperature detection element are attached to the outside air side of the mechanical seal of the pump. A liquid leakage detection element for detecting leakage, a connection housing housing a connection board for temporarily consolidating the output circuits of each of the detection elements, and a connection box connected to the output circuit of each detection element from the connection board. A pump safety monitoring device comprising: an alarm generation circuit; and an alarm attached to the alarm generation circuit that issues an alarm when at least one of the outputs of each of the detection elements exceeds an alarm set value; Each output circuit of the vibration detection element, temperature detection element, and liquid leakage detection element is equipped with an intrinsically safe barrier that prevents electrical energy that could become an ignition source from being input to the side of each detection element by detecting the alarm generation circuit. 2
7. A pump safety monitoring device characterized in that it has an intrinsically safe explosion-proof structure by being connected to the alarm generating circuit through a wire 7. 6. The pump safety monitoring device according to claim 5, wherein the temperature detection element is a heat-sensitive thyristor. 7. The pump safety monitoring device according to claim 5, wherein the liquid leak detection element is an oil detection resistor whose electrical resistance becomes high upon contact with a flammable liquid. 8. The pump safety monitoring device according to claim 5, wherein the alarm is an alarm indicator lamp, a buzzer, or both an alarm indicator lamp and a buzzer.