JP2005055243A - Inundation detector and inundation alarm system having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inundation detector that can be maintained and managed easily and cannot be damaged easily, and to provide an inundation alarm system having the inundation detector in the inundation detector for detecting the inundation of a cargo hold and the inundation alarm system having the same. <P>SOLUTION: The inundation detector has a differential pressure sensor for detecting the difference between pressure in a first air chamber, where a first air pipe is connected, and pressure in a second air chamber, where a second air pipe is connected. the opening end of the first air pipe provided in the cargo hold is positioned at a lower part than the lowest detection water level, and the opening end section of the second air pipe provided in the cargo hold is positioned at an upper part than the highest detection water level. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an inundation detection device for detecting inundation in a cargo hold of a ship and an inundation warning system having the inundation detection device.

Conventionally, a marine vessel is provided with an inundation detection device for detecting inundation as needed. Such an inundation detection device is usually configured to detect that the amount of inundation has reached a predetermined amount by a float sensor or the like, and activates a predetermined alarm device based on detection by the float sensor. Has constructed an inundation warning system for operating a drain pump (see, for example, Patent Document 1).
JP 2002-225789 A

  However, when detecting inundation in an empty space such as a passenger ship or leisure ship, it is possible to detect the inundation with a float sensor, but cargo ships, especially bulk cargo ships and mineral carriers, etc. When cargo is directly stored in the cargo hold as described above, the float sensor cannot detect inundation in the cargo hold, and there is a problem that other sensors must be used.

  In particular, in bulk cargo ships, mineral carriers, etc., when the cargo hold is flooded, a mixed liquid of cargo stored in the cargo hold using the flooded water as a solvent is generated. For example, the cargo is sugar or salt. In the case where it is easy to dissolve in water, it is difficult to reliably detect the inundation state by the sensor, and there is a possibility that the sensor in contact with the high-concentration liquid mixture may fail.

  Moreover, based on the International Convention for the Safety of Life at Sea (SOLAS Convention), it will be obliged to install an inundation warning device in the cargo hold of ships in the future. Since the sensor for detecting inundation is likely to break down, the sensor may be frequently replaced or maintenance work may be required, which may increase the maintenance cost of the ship.

  Therefore, the inundation detection device of the present invention has a differential pressure sensor that detects the difference between the pressure in the first air chamber to which the first vent pipe is connected and the pressure in the second air chamber to which the second vent pipe is connected. The opening end of the first ventilation pipe provided in the cargo hold is positioned below the lowest detection water level, and the opening end of the second ventilation pipe provided in the cargo hold is positioned above the maximum detection water level. In addition, the infiltration of cargo hold was detected by the differential pressure sensor.

  Further, in the inundation detection device of the present invention, connected to a detection tube whose opening end is positioned below the detection water level, and a pressure compensation tube whose opening end is positioned above the inundation water surface, The inundation detection device is composed of a differential pressure switch that operates based on the atmospheric pressure in the detection pipe when the inundation water surface in the cargo hold reaches the detection water surface.

  Further, in the inundation detection device of the present invention, the first detection tube whose opening end is positioned below the first detection water level, and the pressure compensation whose opening end is positioned above the water surface A first differential pressure switch that is connected to the pipe and operates based on the atmospheric pressure in the first detection pipe when the inundated water surface in the cargo hold reaches the first detection water level, and the opening end is connected to the second detection water level. The second detection pipe positioned below the pressure detection pipe is connected to the pressure compensation pipe and operates based on the atmospheric pressure in the second detection pipe when the inundated water surface in the cargo hold reaches the second detection water level. It was set as the inundation detection apparatus which consists of a 2nd differential pressure switch.

  Moreover, in the inundation alarm system of the present invention, in the inundation alarm system in which the alarm means is operated by detecting the inundation of the cargo hold with the inundation detection apparatus, the inundation detection apparatus is provided in the first air chamber connected to the first vent pipe. It has a differential pressure sensor that detects the difference between the pressure and the pressure in the second air chamber to which the second vent pipe is connected, and the opening end of the first vent pipe provided in the cargo hold is below the lowest detected water level. In addition, the opening end portion of the second ventilation pipe provided in the cargo hold is positioned above the maximum detection water level to detect inundation in the cargo hold.

  Further, in the inundation alarm system of the present invention, in the inundation alarm system having an inundation detection device for detecting inundation of the cargo hold, the inundation detection device includes a detection pipe having an opening end positioned below the detection water level, and an inundation Connected to the pressure compensation pipe with the opening end positioned above the water surface, and composed of a differential pressure switch that operates based on the pressure in the detection pipe when the flooded water surface in the cargo hold reaches the detection water surface .

  Moreover, in the inundation alarm system of the present invention, in the inundation alarm system having the inundation detection device for detecting the inundation of the cargo hold, the inundation detection device has a first opening end positioned below the first detection water level. Is connected to a pressure compensation pipe having an opening end positioned above the water surface, and the air pressure in the first detection pipe when the inundated water surface in the cargo hold reaches the first detection water level. A first differential pressure switch that operates based on the second detection pipe, a second detection pipe whose opening end is positioned below the second detection water level, and a pressure compensation pipe, and the inundated water surface in the cargo hold is the second And a second differential pressure switch that operates based on the atmospheric pressure in the second detection tube when the detected water level is reached.

  According to the first and fourth aspects of the present invention, the inundation detecting device calculates the difference between the pressure in the first air chamber to which the first vent pipe is connected and the pressure in the second air chamber to which the second vent pipe is connected. It has a differential pressure sensor to detect, and the opening end of the first ventilation pipe provided in the cargo hold is positioned below the lowest detection water level, and the opening end of the second ventilation pipe provided in the cargo hold is the highest. By locating above the detected water level and detecting the inundation in the cargo hold by the differential pressure sensor, the inundation state can be accurately detected without being affected by the inundation in the cargo hold.

  In addition, even if inundation occurs in the cargo hold, the inundated water does not come into direct contact with the differential pressure sensor, so it is possible to prevent the inundation detection device from being deteriorated due to inundation, and to maintain the inundation detection device. Costs required can be reduced.

  According to the second and fifth aspects of the present invention, the detection pipe in which the opening end is positioned below the detection water level, and the pressure compensation pipe in which the opening end is positioned at a position above the flooded water surface. Connected to the, and the inundation detection device consists of a differential pressure switch that operates based on the pressure in the detection pipe when the inundation water level in the cargo hold reaches the detection water level. It is possible to detect a flooded state.

  Moreover, even if the cargo hold is flooded, the flooded water does not come into direct contact with the differential pressure switch, so that it is possible to prevent the flooded detector from deteriorating due to flooding, which is required for maintenance management of the flooded detector. Cost can be reduced.

  According to the third and sixth aspects of the present invention, the first detection tube in which the opening end is positioned below the first detection water level, and the opening end is positioned at a position above the water surface. And a first differential pressure switch that operates based on the atmospheric pressure in the first detection pipe when the flooded water surface in the cargo hold reaches the first detection water level, Based on the atmospheric pressure in the second detection pipe when the submerged water surface in the cargo hold reaches the second detection water level, connected to the second detection pipe positioned below the detection water level of 2 and the pressure compensation pipe. By adopting the inundation detection device including the operating second differential pressure switch, it is possible to detect the two water levels of the first detection water level and the second detection water level. Furthermore, since the pressure compensation of the first differential pressure switch and the second differential pressure switch can be performed with a single pressure compensation tube, it is possible to provide a highly accurate inundation detection device at low cost.

  The inundation detection device of the present invention and the inundation alarm system having the inundation detection device form a closed space by the water surface that rises with the inundation, and the internal pressure increases while the volume decreases as the water surface further rises. Infiltration detection is performed by using the pressure change in the closed space, and this change in pressure is detected by using a differential pressure sensor or a differential pressure switch.

  Hereinafter, the first embodiment will be described in detail based on the drawings. FIG. 1 is a schematic explanatory view showing a state in which a flooding alarm system having an inundation detection device B1 of the first embodiment is arranged in a bulk cargo ship A having a cargo compartment, and FIG. 2 is an inundation detection device B1. It is a system configuration | structure figure of the inundation warning system which has this.

  The bulk carrier A is provided with a plurality of cargo holds a, and the cargo hold a is configured to receive a required cargo such as ore, coal, salt, sugar, flour, or the like as it is. And after the cargo is accommodated, each cargo hold a can be sealed in order to prevent inundation and the like.

  As shown in FIG. 2, the inundation detection device B1 includes a detection unit b1 having a differential pressure sensor 30 and a low water level detection signal S42 based on an output signal S30 output from the differential pressure sensor 30 of the detection unit b1. An output signal adjustment unit b2 that can output the high water level detection signal S43.

  The detection unit b1 includes a first air chamber 10 and a second air chamber 20 provided in parallel to the differential pressure sensor 30 so as to sandwich the differential pressure sensor 30 via a flexible membrane, and the first air chamber 10 The first vent pipe 11 has one end connected to the second air chamber 20 and the second vent pipe 21 has one end connected to the second air chamber 20. 1 and 2, reference numeral 12 denotes a first filter provided at the end of the first vent pipe 11, and 22 denotes a second filter provided at the end of the second vent pipe 21.

  In particular, the first vent pipe 11 and the second vent pipe 21 each have an open end inserted into the cargo hold a, and the open end of the first vent pipe 11 is positioned below the lowest detected water level L1, and 2 The opening end of the vent pipe 12 is positioned above the maximum detected water level L2.

  Therefore, when the cargo hold a is submerged to the lowest detected water level L1, the opening of the first vent pipe 11 is closed with water, and the first air chamber 10 and the first air chamber 10 communicated with the first air chamber 10 are connected. The internal space of the trachea 11 is a closed space Q.

  On the other hand, the opening end of the second vent pipe 12 is positioned above the maximum detected water level L2, so that the second air chamber 20 and the internal space of the second vent pipe 12 communicating with the second air chamber 20 are provided. Is always an open space. At this time, although the cargo hold a is configured to be able to be sealed, the cargo hold a is always at atmospheric pressure because it is not completely sealed, so the pressure in the second air chamber 20 is also large. It is almost equal to atmospheric pressure. Here, the pressure in the second air chamber 20 is P2.

  When the amount of water in the cargo hold a increases, the liquid level W in the cargo hold a rises, and as the liquid level rises, the liquid level w in the first vent pipe 11 rises as shown in the schematic diagram of FIG. To do.

  When the liquid level w in the first vent pipe 11 rises, the accumulation of the above-mentioned closed space Q is reduced by the rise in the liquid level w. As the volume decreases, the internal pressure of the closed space Q, that is, the first The pressure in one air chamber 10 will rise. The pressure in the first air chamber 10 is P1.

  On the other hand, even if the liquid level W in the cargo hold a rises, the pressure P2 in the second air chamber 20 is always atmospheric pressure, so P1> P2.

  The differential pressure sensor 30 outputs a pressure difference between the pressure P1 in the first air chamber 10 and the pressure P2 in the second air chamber 20 as an output signal S30.

  As shown in FIG. 2, the output signal adjustment unit b2 amplifies the output signal S30 output from the differential pressure sensor 30, and outputs the low water level detection signal S42 from the amplified signal amplified by the amplifier circuit 41. The first detection signal generation circuit 42 to be generated and the second detection signal generation circuit 43 to generate the high water level detection signal S43 from the amplified signal.

  The first detection signal generation circuit 42 includes a first multiplier 42a that multiplies the amplified signal by a detection signal for the lowest detection water level L1, a first comparator 42b that generates a detection signal for the lowest detection water level L1, and a lowest The first output control transistor 42c outputs a low water level detection signal S42 when the amplified signal obtained by multiplying the detection signal for the detection water level L1 is equal to or greater than a predetermined value.

  Connected to the first comparator 42b are a first differential circuit 42d that supplies an adjustment potential for adjusting the detection accuracy of the lowest detection water level L1, and a first level adjustment circuit 42e that adjusts the level of the lowest detection water level L1. By adjusting the first differential circuit 42d and the first level adjustment circuit 42e, the lowest detected water level L1 can be set to an arbitrary height.

  The second detection signal generation circuit 43 includes a second multiplier 43a that multiplies the amplified signal by a signal for detecting the highest detection water level L2, and a second comparator 43b that generates a signal for detection of the highest detection water level L2. The second output control transistor 43c outputs a high water level detection signal S43 when the amplified signal obtained by multiplying the detection signal for the highest detection water level L2 is equal to or greater than a predetermined value.

  Connected to the second comparator 43b is a second differential circuit 43d for supplying an adjustment potential for adjusting the detection accuracy of the highest detection water level L2, and a second level adjustment circuit 43e for adjusting the level of the highest detection water level L2. By adjusting the second differential circuit 42d and the second level adjustment circuit 42e, the maximum detected water level L2 can be set to an arbitrary height.

  The low water level detection signal S42 or the high water level detection signal S43 output from the inundation detection device B1 is input to the remote control circuit 2 via the connection wiring 1 as shown in FIG. A required output is given to the alarm panel 4 provided in the steering chamber 3 of the ship A to notify that the cargo hold a is inundated.

  The remote control circuit 2 collectively manages a plurality of cargo holds a, and is arranged in the vicinity of the cargo hold a, while the remote control circuit 2 and the alarm panel 4 are connected by a connection cable 5 capable of multiplex transmission. Thus, the wiring work can be performed very easily, and the installation cost of the inundation detection device B1 on the existing bulk carrier A can be reduced.

  In addition, since the inundation detection device B1 detects the water level using the pressure difference as described above, the differential pressure sensor 30 portion and the output signal adjustment portion b2 portion should be accommodated in the explosion-proof case. Thus, even when cargo that may cause dust explosion-proofing such as flour is stored in the cargo hold a, it can be safely used.

  Furthermore, in the inundation detection device B1, since the second vent pipe 12 is provided, the second vent pipe 12 can compensate the temperature of the cargo hold a and the rise or fall of the internal pressure. It is possible to suppress malfunction of the sensor 30 and improve detection accuracy.

  Moreover, since the water that has entered the cargo hold a only contacts the first vent pipe 11, there is no risk of causing damage to the differential pressure sensor 30 due to the water that has entered the cargo hold a, and the inundation detection device. B1 maintenance costs can be reduced.

  In the remote control circuit 2 of the present embodiment, when the low water level detection signal S42 or the high water level detection signal S43 is input from the inundation detection device B1, the low water level detection signal S42 or the high water level detection signal S43 continues for a predetermined time. When it is input, the alarm panel 4 is operated by outputting to the alarm panel 4.

  As a result, the inundation detection device B1 is activated instantaneously due to the swinging of the inundated water surface caused by rolling or pitching of the bulk carrier A, and the alarm panel 4 can be prevented from being activated instantaneously. The operation reliability can be improved.

  In FIG. 1, reference numeral 6 denotes a float switch that detects flooding of the boson store, and a detection signal from the float switch 6 is input to the bow drainage control circuit 7. When the amount of water in the bosun store reaches a predetermined amount, drainage is performed by operating the drainage pump 8 by the bow drainage control circuit 7. The bow drainage control circuit 7 is also connected to the remote control circuit 2 so that a required alarm can be output to the alarm panel 4 via the remote control circuit 2.

  Hereinafter, the second embodiment will be described in detail based on the drawings. FIG. 4 is a schematic explanatory view showing a state in which a flood alarm system having the flood detection device B2 of the second embodiment is arranged on a bulk carrier A similar to the second embodiment, and FIG. FIG. 3 is a schematic configuration diagram of an inundation detection device B2. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this embodiment, the inundation detection device B2 includes a first differential pressure switch (not shown) connected to a first detection pipe 51 that detects the lowest detection water level L1, and a second detection pipe 52 that detects the highest detection water level L2. The first differential pressure switch and the second differential pressure switch are accommodated in an explosion-proof case 53. 4 and 5, 54 is a first filter attached to the opening end portion of the first detection tube 51, and 55 is a second filter attached to the opening end portion of the second detection tube 52.

  As shown in FIG. 5, the first differential pressure switch includes a first detection pipe 51 having an opening end positioned below the lowest detection water level L1, which is the first detection water level, and a position above the water surface. Is connected to a pressure compensation pipe 56 having an opening end positioned at the bottom, and a required detection signal is output when the flooded water surface in the cargo hold a reaches the lowest detection water level L1.

  That is, when the flooded water level in the cargo hold a reaches the lowest detection level L1, one end of the first detection tube 51 is closed by the flooded water surface, the first detection tube 51 becomes a closed space, and the flooded water level rises. Along with this, the volume of the enclosed space decreases and the pressure in the enclosed space increases. This pressure is P1 ′.

  On the other hand, in the pressure compensation pipe 56 connected to the first differential pressure switch, the pressure in the pressure compensation pipe 56 matches the pressure in the cargo hold a even if the flooded water level in the cargo hold a rises. No pressure increase occurs. This pressure is P2 ′.

  Therefore, when the inundated water level in the cargo hold a reaches the lowest detection water level L1, P1 ′> P2 ′, and this pressure difference is detected by the first differential pressure switch.

  When the differential pressure switch is used in this way, a slight pressure difference can be detected. Therefore, the minimum detection water level L1 can be easily adjusted only by adjusting the arrangement position of the opening end of the first detection tube 51. Detection can be performed, and the output signal adjustment unit b2 of the first embodiment described above is not necessary, and the installation work of the inundation detection device B2 can be easily performed.

  As shown in FIG. 5, the second differential pressure switch includes a second detection pipe 52 having an opening end positioned below the highest detection water level L2, which is the second detection water level, and a position above the water surface. Is connected to a pressure compensation pipe 56 having an opening end positioned at the bottom, and a required detection signal is output when the flooded water surface in the cargo hold a reaches the lowest detection water level L2.

  The second differential pressure switch detects the lowest detection water level L2 based on the same principle as the first differential pressure switch, and can easily detect the highest level simply by adjusting the position of the open end of the second detection tube 52. The water level L2 can be detected, and the output signal adjustment unit b2 of the first embodiment described above can be dispensed with.

  In particular, the first differential pressure switch and the second differential pressure switch share the pressure compensation pipe 56, whereby the water immersion detection device B2 can be configured at low cost.

  The detection signal output from the first differential pressure switch or the second differential pressure switch is input to the transmission device 57 provided adjacent to the explosion-proof case 53. As shown in FIG. 4, a plurality of transmission devices 57 provided in the bulk carrier A are connected in series via transmission wiring 58 and connected to an alarm panel 4 provided in the steering chamber 3 of the bulk carrier A. Thus, it is possible to notify that the cargo hold a is flooded. In this way, by connecting the transmission devices 57 in series, the installation work of the transmission wiring 58 can be easily performed, and the work cost can be reduced.

  Even in the above-described infiltration detection device B2, the transmission device 57 outputs the alarm panel 4 to the alarm panel 4 when a detection signal is continuously output from the first differential pressure switch or the second differential pressure switch for a predetermined time. 4 is activated. As a result, the inundation detection device B2 is activated instantaneously due to the rocking of the inundated water surface caused by rolling or pitching of the bulk carrier A, and the alarm panel 4 can be prevented from being activated instantaneously. The operation reliability can be improved.

  In this embodiment, the cargo hold a ′ on the bow side of the bulk carrier A is also used as a ballast tank, and a predetermined amount of water can be injected into the cargo hold a ′.

  In FIG. 4, reference numeral 61 denotes a float switch for detecting the flooding of the boon store, and a detection signal from the float switch 61 is input to the bow drainage control circuit 60. When the amount of water inundation at the bosun store reaches a predetermined amount, drainage is performed by operating the drainage pump 62 by the bow drainage control circuit 60. In FIG. 4, 63 is a motor for operating a motor valve (not shown). The bow drainage control circuit 60 can also control the drainage work of the cargo hold a ′ as a ballast tank. The bow drainage control circuit 7 is also connected to the alarm panel 4 via an appropriate connection wiring 64 so that the flooding information of the Bosun store can be output to the alarm panel 4.

1 is a system configuration diagram of a bulk carrier provided with an inundation warning system according to the present invention. It is a schematic explanatory drawing of the water immersion detection apparatus concerning this invention. It is explanatory drawing of the detection mechanism of the inundation detection apparatus concerning this invention. 1 is a system configuration diagram of a bulk carrier provided with an inundation warning system according to the present invention. 1 is a schematic configuration diagram of a water immersion detection device according to the present invention.

Explanation of symbols

A Bulk carrier a Cargo hold
B1 Inundation detector
B2 Inundation detection device
b1 detector
b2 Output signal adjuster
S30 output signal
S42 Low water level detection signal
S43 High water level detection signal
L1 Minimum detection water level
L2 Maximum detection water level 1 Connection wiring 2 Remote control circuit 3 Wheelhouse 4 Alarm panel 5 Connection cable
10 First air chamber
11 First vent pipe
12 First filter
20 Second air chamber
21 Second vent pipe
22 Second filter
30 Differential pressure sensor
41 Amplifier circuit
42 First detection signal generation circuit
42a First multiplier
42b First comparator
42c 1st output control transistor
42d First differential circuit
42e First level adjustment circuit
43 Second detection signal generation circuit
43a Second multiplier
43b Second comparator
43c Second output control transistor
43d Second differential circuit
43e Second level adjustment circuit

Claims (6)

  The first pressure sensor provided in the cargo hold has a differential pressure sensor for detecting a difference between a pressure in the first air chamber connected to the first vent pipe and a pressure in the second air chamber connected to the second vent pipe. The opening end of the ventilation pipe is positioned below the lowest detection water level, and the opening end of the second ventilation pipe provided in the cargo hold is positioned above the maximum detection water level, so that the differential pressure sensor An inundation detecting device for detecting inundation in the cargo hold.   The detection pipe with the open end positioned below the detection water level and the pressure compensation pipe with the open end positioned at a position above the inundation water surface are connected. The inundation water surface in the cargo hold reaches the detection water surface. An inundation detection device comprising a differential pressure switch that operates based on the atmospheric pressure in the detection tube. The first detection pipe whose opening end is positioned below the first detection water level, and the pressure compensation pipe whose opening end is positioned above the water surface are connected to the inundated water surface in the cargo hold. A first differential pressure switch that operates based on the atmospheric pressure in the first detection tube when the first detection water level is reached;
A second detection pipe whose opening end is positioned below the second detection water level is connected to the pressure compensation pipe, and a second case where the water level in the cargo hold reaches the second detection water level. An inundation detection device comprising a second differential pressure switch that operates based on the atmospheric pressure in the detection tube. In an inundation warning system having an inundation detection device that detects inundation in a cargo hold,
The inundation detection device includes a differential pressure sensor that detects a difference between a pressure in a first air chamber to which a first vent pipe is connected and a pressure in a second air chamber to which a second vent pipe is connected. The opening end of the first vent pipe provided in the warehouse is positioned below the lowest detection water level, and the opening end of the second ventilation pipe provided in the cargo hold is positioned above the maximum detection water level. An inundation alarm system for detecting inundation in the cargo hold. In an inundation warning system having an inundation detection device that detects inundation in a cargo hold,
The inundation detection device is connected to a detection pipe whose opening end is positioned below the detection water level and a pressure compensation pipe whose opening end is positioned above the inundation water surface, and inundates the cargo hold. An inundation alarm system comprising a differential pressure switch that operates based on the atmospheric pressure in the detection pipe when the water surface reaches the detection water surface. In an inundation warning system having an inundation detection device that detects inundation in a cargo hold,
The inundation detection device is
The first detection pipe whose opening end is positioned below the first detection water level, and the pressure compensation pipe whose opening end is positioned above the water surface are connected to the inundated water surface in the cargo hold. A first differential pressure switch that operates based on the atmospheric pressure in the first detection tube when the first detection water level is reached;
A second detection pipe whose opening end is positioned below the second detection water level is connected to the pressure compensation pipe, and a second case where the water level in the cargo hold reaches the second detection water level. A submersion warning system comprising a second differential pressure switch that operates based on the atmospheric pressure in the detection tube.

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