The present invention relates to a debris management device for a sprinkler system. Fluid flow systems, such as sprinkler systems are widely used in onshore and offshore installations, such as oil and gas platforms, to contain or suppress fire. During operation of the sprinkler system, it is likely that scale, debris and other pollutants will build up and become a problem. Such systems normally draw on the surrounding salt water and direct it though the sprinkler system to the fire.

As well as a variety of water borne debris or particulates, such as dirt and indeed marine life, scale is typically formed by the precipitation of mineral compounds from water, such as calcium carbonate or calcium sulphate, due to pressure and/or temperature changes in the pipeline. Corrosion in pipelines can build up along the inner wall of pipe and also results in debris entering the system. Marine growth can also cause blockage problems. Salts can also crystallise and cause blockage problems. The by-products of salt water as a delivery fluid are also a problem and it is known that this has contributed to firefighting /deluge systems offshore failing where there has been loss of life, asset and indeed oil spills.

It is known to provide an inline filter between the salt water inlet and the nozzles, in order to mitigate the risk of the debris blocking nozzles. However the inventor of the present invention has noted that the filters themselves may become blocked, which in turn chokes water flow to the nozzles. WO 2015/150836 discloses a filter which can mitigate blockages in a downstream nozzle. Whilst generally satisfactory, the inventor of the present invention has developed a debris management device for a sprinkler system.

A debris management device for a sprinkler system, the debris management device comprising:

a housing having an inlet and an outlet;

a filter in the housing, wherein fluid flow between the inlet and the outlet of the housing must pass through the filter, the filter having a plurality of inlets therein;

a fluid flow control device downstream of the filter;

wherein the fluid flow control device is adjustable to control fluid flow downstream of the filter. Thus in use the fluid flowing into the debris management device can vent to atmosphere. The fluid flow control device may be attached to the outlet of the housing.

Thus the fluid flow control device may be in fluid communication with and downstream of the outlet of the housing. The filter is typically over the outlet. At least a portion of the internal diameter of the housing is normally larger than the inner diameter of the pipe from which it is configured to extend. This provides capacity to hold debris between the filter and the housing. It may be larger by a multiple of at least 1.2 or at least 1.4. For example, the pipe from which it extends may have an internal bore of 0.75 - 1.25" and the internal diameter of at least a portion of the housing is 1.5 - 2.5".

Said portion may be at least 25% of the length of the housing, or at least 50% or at least 75%. The filter is normally a fluid flow conduit. The filter normally has an outer surface and a throughbore. The filter may be tubular in shape. The filter may have a first end and a second end. The throughbore of the fluid flow conduit normally has a cross-sectional area. The cross-sectional area of the throughbore of the fluid flow conduit may be referred to as an internal cross-sectional area.

The plurality of inlets typically provide fluid communication between the outer surface and the throughbore. The plurality of inlets are typically slot shaped. The width of the slots is preferably less than the diameter of any downstream passage, such as the flow control device or an exit to atmosphere. In this way, any debris which proceeds through the slots will not block the exit to atmosphere.

They may have a diameter of from 0.1 - 10mm, preferably 0.5 - 2mm. The spacing between the slots may be slightly larger, such as 1 - 12mm, or 1.5 - 4 mm. Preferably the solid state area (i.e. outside of the inlets) is larger than the filter area (the inlets) in order to provide stability to the filter. The filter typically has an end inlet and an outlet. The end inlet of the filter typically has an end inlet cross-sectional area. The outlet of the filter is normally positioned through the outlet of the housing. The outlet of the filter typically has an outlet cross-sectional area. The cross-sectional area of the end inlet of the filter is typically less than the cross-sectional area of the outlet of the filter.

The housing may be referred to a debris chamber. When the debris management device is part of a sprinkler system, debris in the fluid flow is typically drawn into the debris chamber. It is an advantage of certain embodiments of the present invention that when the debris management device is part of a sprinkler system, debris in the fluid flow is typically managed and encouraged into specific locations, rather than more randomly distributed throughout the sprinkler system. It may be a further advantage of the present invention that this may reduce service and maintenance costs and/or the associated risks.

The fluid flow control device is typically adjustable to control the fluid flow rate and/or volume of fluid flow therethrough and therefore also through the outlet of the housing. The fluid flow control device may have at least a first and a second setting. The first setting allows a greater fluid flow rate and/or volume of fluid to flow through the fluid flow control device compared to the second setting. The first setting may use a first larger diameter aperture in the fluid flow control device. The second setting may use a second smaller diameter aperture in the fluid flow control device. The first aperture allows a greater fluid flow rate and/or volume of fluid to flow through the fluid flow control device compared to the second aperture.

The inventor of the present invention has noted that on start-up more debris may have built up in the system over time. Therefore a purge of the system can clear this accumulated debris. In use, the fluid flow control device may be opened at the first larger aperture to clear the system of debris on start up, and then switched to the second smaller aperture to continue a fluid and debris flow towards the delivery line filter.

For certain embodiments therefore, the first larger aperture is larger than an aperture towards nozzles in nozzle branches. This allows for a greater flow rate through the delivery line filter and first aperture of the fluid flow control device, compared to the flow rate to the nozzles, and so preferentially directs the initial flow and accumulated debris through the delivery line filter rather than the nozzles. The second aperture is sized to match the flow rate through the nozzles, so that pressure can be maintained through the nozzles. Therefore it may be +1-20%, preferably +/-10% of the size of an aperture in the nozzle branches directing flow to the nozzles.

The diameter of the second aperture may be from 50 to 5%, normally from 50 to 25% and typically from 40 to 30% of the diameter of the first aperture. The fluid flow control device is typically a ball valve. A ball of the ball valve may have one, typically two apertures. The two apertures may be the first and the second aperture. The first aperture therefore typically has a greater diameter compared to the second aperture. Rotation of the ball in the ball valve can therefore typically change the fluid flow rate and/or volume of fluid flow through the fluid flow control device. The first aperture with a greater diameter typically allows a greater fluid flow rate and/or volume of fluid to flow through the fluid flow control device compared to the second aperture with a smaller diameter.

The fluid flow control device may be any valve. The fluid flow control device may be a fluid flow restrictor or fluid flow limiter.

Adjustment of the fluid flow control device to control the fluid flow downstream of the filter, normally through the outlet of the housing, may be remote from the debris management device and/or automatic. Adjustment of the fluid flow control device to control the fluid flow through the outlet of the housing may be timed, that is the fluid flow control device may be adjusted after a period of time to change the fluid flow rate and/or volume of fluid flow through the outlet of the housing and/or change the fluid flow control device from the first to the second setting. The period of time varies depending on a number of system-specific variables, such as the size of the filter, the size of the filter outlet, the size of a header, and the volumes and pressures. Thus the period of time is very variable and may be for example as little as 10 seconds or for example more than two minutes or for example as much as 20 minutes. When the fluid flow control device is a ball valve comprising a ball with a first aperture having a greater diameter compared to a second aperture and adjustment of the fluid flow control device to control the fluid flow through the outlet of the housing is timed, the ball of the ball valve may be rotated after for example 30 seconds to direct fluid flow from through the first aperture to the second aperture. This reduces the fluid flow rate and volume of fluid flow through the fluid flow control device.

It is an advantage of certain embodiments of the present invention that when the fluid flow control device is part of a sprinkler system for helping to contain, mitigate or extinguish a fire, the sprinkler system and debris management device can operate concurrently and debris in the fluid flow may be removed from the sprinkler system while it is in operation.

The fluid flow control device typically has an inlet and an outlet. The inlet is typically in fluid communication with the outlet of the housing. The outlet typically provides a fluid outlet from the debris management device. The fluid flow control device may be downstream of the outlet of the housing.

The debris management device may direct the fluid flow out of the housing to a collection tray, or dump it overboard. Alternatively it may be directed to a nozzle.

However, the primary function of the debris management device is to draw debris away from a primary supply line used for other nozzles, rather than to filter debris for a downstream nozzle. Any downstream nozzle may thus be a "sacrificial" nozzle.

Preferably, the functioning of such a nozzle would not be necessary for the overall fire safety management plan, because debris is encouraged into the debris management device, in order to keep other nozzles relatively clear of debris.

The nozzle is typically in fluid communication and/or attached to the outlet of the fluid flow control device.

The debris management device is normally part of a sprinkler system. The sprinkler system and typically a spray of fluid, normally water, from the nozzle may be used to help contain, mitigate or extinguish a fire. The debris management device may be attached and/or in fluid communication with a larger or a smaller bore fluid supply pipe. The larger bore fluid supply pipe normally has a greater internal diameter compared to the smaller bore fluid supply pipe. The larger bore fluid supply pipe may have an internal diameter of from 4 - 12", typically from 6 - 10". The smaller bore fluid supply pipe may have an internal diameter of from 0.5 to 4", typically from 1 to 2.5".

The filter typically substantially extends into the housing. The filter typically substantially extends between the outlet and the inlet of the housing. The inlet is typically opposite and/or opposed to the outlet. The filter may extend greater than 50%, normally greater than 75% and typically greater than 80% of the distance between the inlet and the outlet of the housing. The ratio of the length to width of the filter is normally from 2 to 20, and typically from 5 to 10. The length of the filter may be at least 6", optionally at least 8". Slots may extend for at least 50% of the length of the filter, optionally at least 70% or at least 90%. Thus this is relatively long, though serves to provide capacity to the housing to contain more debris. For example, where debris has accumulated in the housing the relatively long filter can still provide a filter length to be free to allow flow therethrough to atmosphere for a longer period of time than if the filter was covered by debris.

The debris management device may part of an open atmospheric system. The fluid flow control device is adjustable to control fluid flow downstream of the filter. The inlet and the outlet of the fluid flow control device are in fluid communication such that fluid flow from the outlet of the housing may be maintained, this fluid flow being to atmosphere.

The debris management device may use one or more of pressure, flow path, fluid density and gravity to draw debris down into the housing. The pressure may be provided by a pump pulling and/or flowing fluid into the system. The flow path may be provided by the filter and housing arrangement. The fluid density and gravity may be provided by the relative orientation of the device. The position of the debris management device and therefore the filter at the end of a supply and/or delivery line of a sprinkler system, reduces the chance of a blockage in the sprinkler system. This in unlike conventional systems that might use an inline filter which itself can block. According to a further aspect of the invention, there is provided a sprinkler system for marine environments, comprising the debris management system described herein. According to a yet further aspect of the invention there is provided a method of using the debris management system for a sprinkler system in a marine environment. A marine environment is particularly susceptible to rust and other difficult conditions. Moreover the supply of fluids to the sprinkler system is typically taken from the surrounding salt water, which includes debris.

An embodiment of the invention will now be described by way of example only and with reference to the accompanying drawings, in which:

Figure 1 is a schematic sectional view of the debris management device in a large bore portion of a sprinkler system in accordance with an embodiment of the present invention;

Figure 2 is a schematic sectional view of the debris management device in a small bore portion of a sprinkler system in accordance with another

embodiment of the present invention; and

Figure 3 shows the filter in more detail.

Figure 1 is a schematic sectional view of the debris management device 80 in accordance with an embodiment of the present invention. The debris management device 80 comprises a housing 82 having an inlet 84 and an outlet 86 and also has a filter 88 in the housing 82, wherein fluid flow (not shown) between the inlet 84 and the outlet 86 of the housing must pass through the filter 88. The filter 88 has a plurality of inlets 83 therein. The debris management device 80 comprises a fluid flow control device 90 attached to the outlet 86 of the housing 82. The fluid flow control device 90 is adjustable to control fluid flow through the outlet 86 of the housing 82.

The filter 88 comprises a threaded portion 87 and a filter tube 89 which comprises the plurality of inlets 83. The plurality of inlets 83 are slot shaped.

The fluid flow control device 90 is a ball valve comprising a ball 91 with a first aperture 92 having a greater diameter compared to the second aperture 93. Adjustment of the fluid flow control device 90 to control the fluid flow (not shown) through the outlet 86 of the housing 82 may be timed. The first aperture 92 is used when the debris management device and larger sprinkler system is first put into to use. The increased fluid flow through the first aperture 92 helps to draw debris accumulated in the system into the housing 81 and away from other components of the larger sprinkler system. After 60 seconds, for example, the ball valve is rotated using the actuator 94 and fluid flow is then through the second aperture 93. This ensures more of the fluid flow, typically water, is directed to the parts of the sprinkler system used for helping to contain, mitigate or extinguish a fire but some debris is still drawn into the housing 81 and away from other components of the larger sprinkler system. Moreover, as flow can continue through the smaller aperture, debris continues to be drawn into the debris management device, away from the sprinklers.

The size of the first aperture 92 is typically larger than an aperture directing fluid onto the nozzles, so that the initial flow of fluids is directed to the device 80. The size of the second aperture 93 is sized to be similar to that of the aperture directing fluid onto the nozzles, so that the system can be suitably pressurised.

The top 88a of the filter tube 89 is prism-shaped, with a pointed apex, and comprises an inlet having two slots 88b and 88c.

In use, any large particles of debris (not shown) in the fluid flow (not shown) can be fractured and/or broken into smaller particles if they make contact with the pointed apex 88a of the filter tube 89. The slots 88b & 88c help to prevent any debris above a predetermined size from entering the throughbore of the filter tube 89. Debris (not shown) above this predetermined size will collect inside 81 the housing 82 and may itself assist in the filtering action.

It is an advantage of certain embodiments of the present invention that the pointed apex 88a of the filter tube 89 can break larger particles of debris into smaller particles, because this may help to mitigate the risk of the filter becoming blocked, and also more debris can potentially be stored in the housing compared to conventional containers. It is an advantage of certain embodiments of the present invention that the debris may be collected in the housing below the inlets 83, because this can help to mitigate the risk of the inlets becoming blocked with large particles of debris.

Furthermore, it is an advantage of certain embodiments of the present invention that in use, the inlets 83 can help to reduce the volume of debris, such as scale, rust particles and salt deposits, being distributed out with the debris management device, thus reducing the risk of blockages to the larger sprinkler system.

The two slots 88b & 88c are at right-angles to each other, and the two slots 88b & 88c cross each other at the apex 88a of the prism at the top of the filter tube 89. At the four ends of the two slots 88b & 88c there is a circular hole.

The debris management device 80 further includes a pressure gauge 98 and an isolation valve 99.

The housing is disconnectable from the rest of the sprinkler network. To do this, the isolation valve 99 is closed, and the housing detached and debris therein emptied, before being reattached and the isolation valve 99 opened again. An advantage of such embodiments is that this may be done when the sprinkler system is still online and operable. In contrast, clearing in-line filters requires intervention in the direct flowpath between the inlet and the nozzles, and so requires a sprinkler system to be shut down. Consequently regulations may require work on the installation protected by the sprinkler system to be suspended. The debris management device 80 shown in Figure 1 is part of a larger sprinkler system 100a and 100b.

Figure 2 is a schematic sectional view of the debris management device 80 in accordance with another embodiment of the present invention. Many of the features of the debris management system shown in Figure 2 are the same or at least comparable to those features of the debris management system shown in Figure 1. The same or at least comparable features shown in Figure 2 have been given the same reference numerals. The debris management device 80 comprises a housing 82 having an inlet 84 and an outlet 86 and also has a filter 88 in the housing 82, wherein fluid flow (not shown) between the inlet 84 and the outlet 86 of the housing must pass through the filter 88. The filter 88 has a plurality of inlets 83 therein. The debris management device 80 comprises a fluid flow control device 90 attached to the outlet 86 of the housing 82. The fluid flow control device 90 is adjustable to control fluid flow through the outlet 86 of the housing 82. In this embodiment an outlet 91 of the fluid flow control device 90 is in fluid

communication with a nozzle 92. In use, water expelled from the nozzle 92 is used to help contain, mitigate or extinguish a fire (not shown).

In this embodiment, the housing has a larger internal diameter than the inner diameter of the pipe from which it extends (and normally of the sprinkler network 34 more generally). The additional volume that results allows for a larger capacity of debris to gather between the filter and the housing. Thus, combined with the longer length of the filter, in certain embodiments, flow can continue through the filter without blockages for a much longer period of time, compared to known filters mounted on a nozzle or pipe, for example.

Figure 3 shows the filter 88 in more detail. The filter has a plurality of inlets 83 therein. The filter 88 comprises a threaded portion 87 and a filter tube 89 which comprises the plurality of inlets 83. The plurality of inlets 83 are slot shaped.

The top 88a of the filter tube 89 is prism-shaped, with a pointed apex, and comprises an inlet having two slots 88b and 88c. The two slots 88b & 88c are at right-angles to each other, and the two slots 88b & 88c cross each other at the apex 88a of the prism at the top of the filter tube 89. At the four ends of the two slots 88b & 88c there is a circular hole.

Modifications and improvements can be incorporated herein without departing from the scope of the invention.