WO2004094963A2

WO2004094963A2 - Fluid detecting means

Info

Publication number: WO2004094963A2
Application number: PCT/GB2004/001611
Authority: WO
Inventors: Paul Brian Luen
Original assignee: Martek Marine Ltd
Priority date: 2003-04-16
Filing date: 2004-04-14
Publication date: 2004-11-04
Also published as: WO2004094963A3; GB0308787D0

Abstract

This invention relates to means of detecting fluid, and is particularly, but not necessarily exclusively, concerned with the detection of water in cargo holds and other compartments of bulk carriers or other sea-going vessels. Water ingress into such as cargo holds can cause considerable damage, and it is known to fit water detectors, but which are restricted as to where they can be fitted, are not easily accessed for maintenance and repair, and do not allow automatic in situ testing and cleaning of filters. Such disadvantages are avoided by the present invention which comprises a fluid sensor, a housing for the fluid sensor, a fluid inlet to the housing, a particulate filter, a fluid outlet from the housing, a support means for the housing, said support means serving as a conduit for fluid to direct fluid to the inlet to the housing, and said conduit being adapted for connection to the external/internal surface of the wall of an enclosed area, in communication with a through hole in the wall or adapted for connection to an open ended pipe/conduit the lower end of which terminates in the lower part of an enclosed area.

Description

FLUID DETECTING MEANS

This invention relates to means of detecting fluid, and is particularly, but not necessarily exclusively, concerned with the detection of water in cargo holds and other compartments of bulk carriers or other sea-going vessels. There are numerous circumstances where there is a need to have early warning of water ingress into an enclosure. This is particularly so with sea-going bulk carrier vessels and their cargo holds and general compartments. Water ingress into a cargo hold of a vessel can cause considerable damage to a cargo in the hold, and excessive water ingress into a hold can put the vessel at risk. it is already known to have water detection means in general compartments of a seagoing bulk carrier such as for example in bilge areas.

Current detection methods would require special structures to be manufactured around the water detectors for mechanical protection from the cargo and cargo machinery operations if such detectors were to be fitted in such locations. Present constructions of water detectors restrict where they can be fitted, and they are not protected against failure as a result of dust accumulation on the switching parts. With a cargo or other solid or fluid in the compartment the water detector could not be isolated and accessible for testing, routine maintenance, repair or replacement, without compromising the integrity of the compartment being served. Present detectors also do not facilitate the testing of the cabling between the detector and control panel for short circuit. Present detectors do not facilitate the automatic in-situ cleaning of filter elements used to protect them and the automatic in-situ functional testing of the detectors.

The object of the present invention is to provide a means of detecting fluid that avoids those disadvantages mentioned above. According to the present invention, a means of detecting fluid comprises a fluid sensor, a housing for the fluid sensor, a fluid inlet to the housing, a particulate filter, a fluid outlet from the housing, a support means for the housing, said support means serving as a conduit for fluid to direct fluid to the inlet to the housing, and said conduit being adapted for connection to the external/internal surface of the wall of an enclosed area, in communication with a through hole in the wall or adapted for connection to an open ended pipe/conduit the lower end of which terminates in the lower part of an enclosed area. Preferably there is a means of injecting water in the reverse direction through the housing, to clean the filter and test that the detector is functioning.

Preferably, the water detector incorporates a resistor to facilitate a control panel check for a short circuit of a sensor cable connecting the fluid sensor to the control panel.

To allow air to be expelled from within the housing as water enters through the filter, bleed holes may be provided at the opposite end of the housing to the filter. At the point of cleaning the filter and testing the detector, water can be injected through one bleed hole to expel air through the other.

The enclosed area may be the cargo hold or other compartment of a sea-going bulk carrier vessel, and the wall may be the bulkhead defining the side or end of the hold or compartment, and the open ended pipe/conduit may be the 'sounding pipe' or bilge washing

( pipe of the hold or compartment.

The support means may be an elbow of tubular material of relatively high strength compatible with that of the bulkhead, and the elbow may be secured to the bulkhead either directly or mated to a pipe extension by welding, in alignment with a through-hole in the bulkhead or secured to an open ended pipe/conduit the lower end of which terminates in the bilge well of an enclosed area using a standard pipe T-piece'

The opposite end of the elbow provides support for the housing of the detecting means, and the housing may be detachably attached to the elbow such as by the provision of mating threads externally of one end at least of the housing and internally of the co- operating end of the elbow. The fluid inlet to the housing being provided with a filter prevents the ingress of particles of solid matter into the housing which could cause failure of the operation of the switch due to dust accumulation on the switching parts and restricts the outflow of injected water from the housing during testing and verification of the operation of the switch.

The fluid sensor within the housing may be a float switch, located at a predetermined height within the housing. Thus, the float may be slidably mounted on a stem dependant from the upper end of the housing, and cable means may be provided to connect the float switch to a remote sensor, or control panel, and the control panel may have visual or audible signal means, or appropriate switch means to connect the control panel to strategically positioned visual or audible signal means.

By having a rigid elbow with an isolation valve at a position accessible to an operative attached to the outer wall of a bulkhead, or secured to an open ended pipe/conduit the lower end of which terminates in the bilge well of an enclosed area, the housing can be held in a vertical condition to suit the employment of a float switch, without the requirement to fabricate special structures around the float switch for mechanical protection from the cargo and cargo machinery operations, and easily accessed by an operative who simply needs to isolate the line with the adjacent valve and unscrew the housing from the elbow to access the float switch for testing services with a cargo or other solid or fluid in the compartment and without compromising the integrity of the compartment being served. By having a filter element at the inlet to the housing which prevents ingress of particulate matter, the float switch can be protected from failure due to the accumulation of dust on its working parts. By having a means of injecting water into the housing and a filter element which restricts the outflow of injected water from the housing, by employment of a control panel controlling the injection of water, the filter element can be automatically cleaned and the float switch can be automatically functionally tested in-situ. By having an integral resistor within the float switch, by employment of a remote sensor or control panel a short circuit in the sensor cabling can be detected and an alarm given to indicate short circuit.

Thus, with the aperture in the bulkhead at a height that represents the maximum safe depth of any water in a cargo hold, and with the housing connected to the elbow and the switch connected to the control panel, any rise in the water level in the hold enters the elbow and is directed into the housing, to lift the float switch to signal the control panel of an unacceptable water level in the cargo hold, and if provided, activate visual and/or audible alarm means. Means may also be provided such that if there is a short circuit in the cabling between the sensor and the control panel, the control panel will activate visual and/or audible alarm means.

Key points with the invention are that the water detector can be screwed directly into or onto a standard pipe fitting or conduit, without the need for additional mechanical protection or support, the incorporation of an inboard filter prevents ingress of particulate matter (which may cause failure of the level switch) but allows ingress of water and the facility to automatically clean the filter element in-situ and automatically provide a true functional test of the detector in-situ.

The water detector is accessible for testing, repair and replacement whilst the vessel is carrying cargo without compromising the integrity of the space being served, and when the water detector incorporates an end of line resistor it facilitates a control panel to check for short circuit of the sensor cable.

An embodiment of the invention will now be described with reference to the accompanying drawings in which:-

Figure 1 is a sectional side elevation of a means of detecting the presence of fluid; and

Figure 2 is a side elevation of two detectors of Figure 1 sited on the wall of a container.

In the drawings a fluid sensor 1 is provided in a housing 2 having a fluid inlet 3 overlaid by a filter 4. Fluid outlets 5 from the housing are provided at the end opposite the inlet 3.

The fluid sensor 1 is formed by a float switch 6 slidably mounted on a support stem 7 depending from a mount 8 attached and extending through an orifice 9 in a top plate 10 to the housing. Extending from the mount 8 is an electrical cable 11 connecting the float switch 6 to a remote control panel, sensor etc., that preferably includes audible and visual signal means.

As is shown in Figure 2, two sensor means are provided, the housing 2 of each of which is attached to one' end of an elbow 12 the opposite end of which is attached to a mounting member 13 attached to the wall 14 of a cargo hold 15 of a vessel, each mount having an access hole 16 leading to the elbow 12 and hence to the housing 2.

Thus, in the event that water enters the cargo hold, and rises until it reaches the first, lower sensing means 1 , water flows through the access hole 16 and into the housing 2, to cause its float 6 to rise and activate switch means such as a read switch, and cause an electrical signal to pass along the cable 11 to a remote control panel, to signal that water is in the hold. If water continues to rise, it is allowed to leak from the housing 2 through the outlet holes 5, to avoid pressurising the housing 2 with potential damage to the float and switch. Further rise of water in the hold will result in water reaching the second upper sensing means 1 , and when its housing 2 fills and its float 6 to rise, to operate its switch, and signal the control means that water has risen to a new height in the hold.

By strategically positioning the two sensing means on the wall of a cargo hold, a first signal can be activated to advise that water is present but at a safe level, and subsequently activate a second signal to advise that water has continued to enter the cargo hold and has reached an unacceptably high level.

At the point of inspection of routine maintenance of the signal mans, and to allow cleaning of the filter 4, water can be caused to flow into the housing 2 through one hole 5, through the filter and out through the inlet 3, with air in the housing automatically expelled through the other hole 5.

Claims

1. A means of detecting fluid characterised by a fluid sensor (1), a housing (2) for the fluid sensor, a fluid inlet (3) to the housing, a particulate filter (4), a fluid outlet (5) from the housing, a support means (12) for the housing, said support means serving as a conduit for fluid to direct fluid to the inlet to the housing, and said conduit being adapted for connection to the external/internal surface of the wall (14) of an enclosed area, in communication with a through hole in the wall or adapted for connection to an open ended pipe/conduit the lower end of which terminates in the lower part of an enclosed area.

2. A means of detecting fluid as in Claim 1 , characterised in that there is a means of injecting water in the reverse direction through the housing, to clean the filter and test that the detector is functioning.

3. A means of detecting fluid as in Claim 1 or Claim 2, characterised in that there is incorporated a resistor to facilitate a control panel check for a short circuit of a sensor cable connecting the fluid sensor to the control panel.

4. A means of detecting fluid as in any of Claims 1 to 3, characterised in that to allow air to be expelled from within the housing (2) as water enters through the filter (4), bleed holes (5) are provided at the opposite end of the housing to the filter.

5. A means of detecting fluid as in any of Claims 1 to 4, characterised in that the support means (12) is an elbow of tubular material of relatively high strength compatible with that of the bulkhead, secured to the bulkhead either directly or mated to a pipe extension by welding, in alignment with a through-hole in the bulkhead or secured to an open ended pipe/conduit the lower end of which terminates in the bilge well of an enclosed area using a standard pipe -piece'

6. A means of detecting fluid as in any of Claims 1 to 5, characterised in that the fluid sensor (1) within the housing (2) is a float switch (6), located at a predetermined height within the housing.

7. A means of detecting fluid as in any of Claims 1 to 6, characterised in that the float is slidably mounted on a stem (7) dependant from the upper end of the housing, and cable means (11) is provided to connect the float switch to a remote sensor, or control panel.

8. A means of detecting fluid as in any of Claims 1 to 7, characterised in that the control panel has visual or audible signal means, or appropriate switch means to connect the control panel to strategically positioned visual or audible signal means.

9. A means of detecting fluid as in any of Claims 1 to 8, characterised in that means are provided such that if there is a short circuit in the cabling between the sensor and the control panel, the control panel will activate visual and/or audible alarm means.