JP3405433B2 - Oil leak detector - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil leak detector for detecting oil leak.

[0002]

2. Description of the Related Art In a transportation pipeline or the like, oil leakage detection means is arranged at a place where leakage is likely to occur, such as a joint portion, from the viewpoint of safety measures, and the oil leakage can be centrally monitored at a monitoring station. It is being appreciated.

Since such oil leakage detecting means is required to have reliability for a long period of time, for example, Japanese Patent Laid-Open No. 5-203
As seen in Japanese Patent No. 533, a combination of a highly oil-absorbent resin that absorbs oil and swells and a switch that electrically detects a swelling displacement of the highly-oil-absorbent resin is used.

[0004]

On the other hand, a pump connected to a pipeline of a petrochemical plant or the like is equipped with a mechanical seal and constantly produces a small amount of oil leakage, so that an abnormal leakage from the mechanical seal occurs. If oil is to be detected by the above-mentioned highly oil-absorbent resin, a small amount of oil leakage during normal operation may cause the highly-oil-absorbent resin to swell gradually, resulting in erroneous detection. Therefore, it is necessary to periodically replace the highly oil-absorbent resin with a new one, which causes a problem that maintenance labor and cost are required.

Further, when a large amount of oil whose temperature is as high as 200 ° C. or more is leaked out, such as in a petroleum refining plant, the highly oil-absorbent resin is denatured before it is swollen, resulting in a detection error. There is a problem of causing it.

The present invention has been made in view of the above problems, and an object thereof is to provide an oil leak detector capable of preventing the detection substance from swelling due to a slight amount of oil leak that occurs in a normal state. To do. Another object of the present invention is to provide an oil leak detector that can reliably detect even if high temperature oil leaks.

[0007]

[Means for Solving the Problems] That is, in order to achieve such a problem, the present invention provides an inflow port connected to a leaked oil monitoring device, and an upper and lower position which is located below the inflow port. A branch body having two outlets provided in such a manner, an emission amount limiting member connected to the outlet on the low side, and an outlet on the high side connected to the outlet on the high side In addition to accommodating an oil absorber that absorbs oil and swells so as to be located at a lower position, a detection unit that detects displacement due to swelling of the oil absorber is provided.

[0008]

A small amount of oil leakage that occurs during normal operation is discharged to the outside of the device on the upstream side of the detection means by the discharge amount limiting member, and is prevented from flowing into the oil absorber.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 shows an embodiment of the present invention. In the figure, reference numeral 1 is a branching body provided with a filter housing chamber 3, and an inflow port 2 through which oil leaked from a monitored device flows, Outflow ports 5 and 6 are formed at two locations that are located lower than the inflow port 2 and have a vertical relationship with each other.

Reference numeral 4 denotes a cylindrical filter, which has an upper opening 4a.
Is connected to the inflow port 2 and the bottom opening 4 b is attached so as to be sealed by the branch body 1. A flow rate adjusting mechanism 10 is connected to the outflow port 5 located on the lower side via a flow path 7 extending downward. The flow rate adjusting mechanism 10 is configured as a needle valve 11 whose valve opening can be adjusted by advancing and retracting a needle 11a with a knob 12.

On the other hand, a detection unit 20, which will be described later, is connected to the outflow port 6 located at the high place side via a pipe 18 so as to be located below the outflow port 6.

Reference numeral 20 denotes the above-mentioned detection unit, which slides on the cylinder 26 also serving as a case, with an oil absorbing body 21 made of a substance which absorbs oil and swells when it comes into contact with the oil, according to the displacement caused by the swelling. A piston 22 made of a heat-resistant resin and provided with a magnetic piece 23 on the upper side, and an oil absorber 21.
When it swells, the reed switch 25 provided at a position where the magnetic force is changed by the magnetic piece 23 is housed, and the oil leaked through the pipe 18 is absorbed by the oil absorber 21.
Is configured to wet.

A terminal casing 30 is attached to the upper end of the detection unit 20, and a cable 28 of the reed switch 25 and a cable 41 of a temperature fuse 40, which will be described later, are relayed by an internal terminal block 31 to connect a resistor, which will be described later. R
It is connected to the transmission cable 32 via t and Ro.
Note that reference numeral 24 in the drawing denotes a window formed in the cylinder 26 for visually recognizing the movement of the piston 22 from the outside.

Reference numeral 40 is a thermal fuse, which is housed in the flow path of the pipe 18 connecting the branch body 1 and the detection unit 20 so as to come into contact with the oil flowing from the branch body 1, and through the cable 41. Are guided to the terminal casing 30.

In this embodiment, when a small amount of oil leak which is constantly generated flows into the inflow port 2, this oil leak flows through the filter 4 and the outflow port 5 on the low side. Road 7
Flow into the needle and the needle valve 11 of the flow control mechanism 10
Is discharged from the system.

Since the oil flowing into the needle valve 11 is filtered by the filter 4, the needle valve 11 is not closed even if dust is contained in the leaked oil, and the discharge amount of the needle valve 11 is reduced. The reliability as the limiting member can be ensured.

Therefore, if the valve opening of the needle valve 11 is adjusted to the upper limit flow rate that does not need to be detected by the knob 12, a slight amount of oil leakage will cause the detection unit 20, that is, the oil absorber 21.
Can be prevented from flowing into.

Next, when oil leakage with a flow rate exceeding the permissible range occurs, the amount of oil leakage flowing into the inflow port 2 exceeds the flow rate that can be discharged from the flow path 7, so the pipe from the outflow port 6 on the high place side. It flows out to 18 and swells the oil absorption body 21 of the detection unit 20.

The piston 22 rises due to the swelling of the oil absorber 21, the magnetic piece 23 approaches the reed switch 25, and the reed switch 25 is switched from OFF to ON. At this time, it can be confirmed by visual observation through the window 24 of the detection unit 20 that the piston 22 has moved to a position where a steady amount or more of oil has leaked.

If a large amount of hot oil leaks, the pipe 18
Detection unit 20 without receiving cooling in the flow path such as
Since the oil absorption body 21 melts and loses its swelling function, the temperature fuse 40 provided in the flow path of the pipe 18 melts and the leakage can be detected.

Needless to say, when the temperature fuse 40 is blown and the oil at the temperature at which the oil absorbing body 21 is swollen flows into the detection unit 20, both the temperature fuse 40 and the reed switch 25 cause a state change, so that detection is performed. can do.

FIG. 2 shows an embodiment of the oil leakage detection circuit, which is a first series circuit composed of a temperature fuse 40 and a resistance Rt, and a second series circuit composed of a reed switch 25 and a resistance Ro. And are connected in parallel, and the current detection means 5 is connected to this.
The constant voltage source V is connected via 0. The resistors Rt and Ro are preferably attached to the terminal block 31 (FIG. 1).

With a small amount of oil leakage during normal operation, the oil absorber 21 does not operate the reed switch 25, so the reed switch 25 is kept in the OFF state, and the current Ia determined by the resistance Rt of the first series circuit is the current. It flows to the detection means 50.

When oil leakage is detected by the oil absorber 21, the reed switch 25 is turned on, so that the sum of the current Ia flowing in the first series circuit and the current Ib flowing in the second series circuit. That is, Ia + Ib flows to the current detection means 50.

Further, when a large amount of oil having a high temperature leaks, the cooling in the flow path becomes insufficient, so that the temperature fuse 40 is melted and the oil absorber 21 cannot swell. Since the switch 25 maintains the OFF state, the current flowing through the current detecting means 50 becomes zero.

When oil leakage is detected by the oil absorber 21 and the thermal fuse 40, the thermal fuse 40 is blown,
Further, since the reed switch 25 is turned on, the current Ib regulated by the resistance Ro of the second series circuit flows through the current detection means 50.

As a specific example, the resistance Rt is 3 kΩ and the resistance R is
When o is 2 kΩ and the voltage of the constant voltage source V is 6 V, the output current value I displayed on the current detecting means 50 is as follows. Normal 2mA Oil leak detection 5mA High temperature oil detection 0mA Oil leak detection and high temperature oil detection 3mA In this way, the current values in each state are different from each other. The condition can be grasped accurately.

[0028]

As described above, according to the present invention, an inlet connected to a leaked oil monitoring device and two inlets located below and above and below the inlet. A branching body having an outlet, a discharge amount limiting member connected to the outlet on the low side, and an outlet on the high side, and located at a lower position than the outlet on the high side In addition to accommodating an oil absorber that absorbs oil and swells, and equipped with a detection means that detects displacement due to swelling of the oil absorber, the amount of leakage oil that is not detected can be discharged outside the system by the discharge amount limiting member. Thus, the oil can be prevented from flowing into the oil absorber, and the swelling of the oil absorber due to a small amount of oil leakage can be prevented.

Further, since the temperature detecting means is provided in the flow path connecting the outlet on the high side of the branch body and the detecting means, even if the oil absorbing body loses its swelling function due to the high temperature oil, the leakage is sure to occur. Oil can be detected.

Further, since the filter is provided between the inflow port and the two outflow ports, the needle valve is prevented from being blocked by the dust contained in the oil leak and the reliability as the discharge amount limiting member is secured. can do.

[Brief description of drawings]

FIG. 1 is a sectional view of an apparatus showing an embodiment of the present invention.

FIG. 2 is a diagram showing an embodiment of an oil leakage detection circuit of the same device.

[Explanation of symbols]

2 Inlet 4 filters 5 Low-side outlet 6 High-side outlet 10 Flow rate adjustment mechanism 20 detection unit 21 Oil absorber 23 Magnetic pieces 25 reed switch 40 thermal fuse

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G01N 33/28 G01M 3/04

Claims (5)

(57) [Claims] 1. A branch body having an inflow port connected to a leaked oil monitoring device and two outflow ports located below and further above and below the inflow port, and a low place. Discharge limiting member connected to the outlet on the high side and the outlet connected to the high side, and absorbs oil to swell so as to be located lower than the outlet on the high side. An oil leakage detector, comprising an oil absorber, and a detector for detecting a displacement of the oil absorber due to swelling. 2. The oil leakage detector according to claim 1, wherein the discharge amount limiting member is a flow rate adjusting means. 3. The oil leakage detector according to claim 1, wherein a temperature detecting means is provided in a flow path connecting the outlet on the high side of the branch and the detecting means. 4. The oil leakage detector according to claim 3, wherein the temperature detecting means is a thermal fuse. 5. The oil leak detector according to claim 1, wherein a filter is provided between the inflow port and the two outflow ports.