Welfare Cabin Water System

Abstract

A free-standing welfare cabin having a water system 200 comprising a pump 203 and UV light 206, which is in flow communication with the pump and operated by a controller 209. The UV light is activated

Description

The present invention relates to welfare cabin water systems, particularly to a water filter / treatment system onboard a welfare cabin. 5 Welfare cabins are enclosures for crew working on-site, for example in a remote location, which provide facilities offering warmth, water, shelter, lighting, toilet facilities, cooking, sleeping, and the like. Welfare cabins are often required to be used as free-standing units without connection to a water mains or electrical grid. io As such they are typically powered by a diesel engine generator set and have a fresh water tank. The fresh water tank needs to be filled frequently throughout use of the cabin. The need for continued maintenance of the welfare cabin represents a large cost and 15 inconvenience to a welfare cabin operator. Over time, the maintenance costs of a welfare cabin can represent a large proportion of the overall cost. GB2581313A discloses use of grey water in welfare cabins to reduce the need for fresh water and the amount of waste water created. Water is received in a grey 20 water tank from one or multiple washing facilities outlets e.g. tap, wash basin and / or drain. A toilet is then arranged to receive water from the grey water tank. The fresh water is still required for use of all other washing facilities within the cabin. 25 There is pressure to reduce energy consumption by welfare cabins so that a cabin can reduce its environmental impact, e.g. being able to be powered entirely by renewable energy and / or to reduce fresh water consumption. In this regard, welfare cabins represent specific challenges because they may not have access to mains water supplies or other potable water sources. Furthermore, welfare cabins 30 can undergo variable levels of use, e.g. potentially requiring water to be stored onboard for days or weeks without being used or else being used by multiple occupants on a daily basis. As such, it is a challenge to develop efficient systems that can accommodate the specific practical demands placed upon welfare cabins. 20 10 25 It is an aim of the invention to provide a welfare cabin water system that mitigates one or more of the above-mentioned problems. 5 Statements of invention There is provided a free-standing welfare cabin having a water system as defined in appended Claim 1. Optional / preferable features of the free-standing welfare io cabin having a water system are defined in the appended dependent claims. Detailed description Practicable embodiments of the invention are described in further detail below with reference to the accompanying drawings, of which: 15 Figure 1 shows a schematic plan view of a welfare cabin layout; Figure 2 shows a schematic of a welfare cabin water system according to an example of the invention. Cabin 20 A free-standing welfare cabin according to an example of the present invention is shown schematically in Figure 1 and generally designated 10. The cabin can be provided in any suitable location, for example, in locations without connection to water or electricity mains. 25 The cabin comprises an outer wall 12 around its perimeter and one or more inner dividing wall 14. The cabin interior is divided by interior walls 14 into separate user rooms / compartments 16, a W / C 18 and an equipment compartment 20. The outer wall 12 provides for a rigid container that is resilient to vandalism. The outer wall may comprise one or more vents to the cabin exterior in any, any combination, or 30 all of the internal compartments. 20 10 25 Each of the user compartments 16, 18 and equipment compartment 20 is provided with a door 24 that opens to the exterior of the cabin 10. The doors 24 each have locks and are designed to be resilient to break-in by way of their fitment into the corresponding frame in the outer wall 12, as well as by the nature of the lock. 5 Electrical components within the user compartments comprise a light, personnel sensor and, optionally, a heater. The personnel sensor typically comprises a proximity sensor and / or movement sensor of a known type. A light sensor may also be provided on the interior or exterior of the cabin to sense the level of io ambient light. A suitable air heater may comprise one or more infra-red heating panel (i.e. a radiative heating panel) but could additionally or alternatively comprise an electrical fan heater of conventional type or another convective heater. A skylight 15 (not shown) may be provided in the roof of the compartment 16 so as to allow entry of ambient light into the compartment interior. One or more solar panel (described below) is mounted on the roof of the cabin 10. The solar panel(s) may be mounted adjacent about the skylight, where present. 20 e.g. between two skylights. A plurality of solar panels are typically provided on the roof. Solar panels may cover a majority, or all, of the roof area of the cabin. For example, greater than or equal to 70% of the roof area may be cover; preferably, greater than or equal to 80%. 25 The solar panels may be mounted co-planar with the roof of the cabin normally (i.e. horizontally in use). Solar panel(s) are additionally fitted to the side of the outer wall 12. Alternative solar panel configurations may be used. In the example of figure 1, the cabin unit 10 is in the form of a larger welfare cabin 30 with the WC 18 and equipment 20 compartments at one end of the cabin 10 and two living / office spaces in thew remainder of the cabin. The user compartments of the cabin 10 could comprise a kitchenette / galley 26, office 28 in addition to the toilet facilities disclosed herein, each separated by internal walls. In other 20 10 25 examples, the compartments could comprise a seating / dining area, storage lockers, washing facilities (e.g. a shower / sink). In some embodiments, the kitchenette may comprise a canteen or seating area. In some embodiments, the cabin comprises a drying room (e.g. to dry wet clothes). In a further example, the 5 cabin could comprise a smaller W / C cabin with just one or two compartments providing W / C facilities. All of the cabin options described above are just examples of welfare cabins to which the invention may be applied. It will be appreciated that a variety of welfare cabin layouts may be accommodated to suit different living and working requirements for different numbers of people. io In various examples, at least one user compartment 16 would comprise a sink with a water dispenser 30 (e.g. a tap or hot wash unit) to provide hot or cold water and a toilet fed by an on-board water system. In various examples of welfare cabins, there will typically be a plurality of water outlets fed by the onboard water system, 15 including one or more cold water tap, one or more hot water tap / tank, one or more toilet, one or more shower or other washing facility, one or more external tap. Other water-fed appliances could be connected to the onboard water system outlets. Each outlet / appliance will typically comprise a valve such that the onboard water system can be pressurised and water will be dispensed through the 20 outlet / appliance on demand upon opening of the valve. Water system Figure 2 shows a schematic of a welfare cabin water system 200 according to an example of the invention. 25 The water system 200 comprises a rainwater collector 201 on the roof of the cabin. The rainwater collector 201 may comprise a sloping roof and / or one or more channel arranged to direct rainwater landing on the roof (or any solar panels thereon) to an opening 201a. The opening 201a may provide an inlet into the 30 water system 200 and may comprise one or more filter, e.g. a mesh / screen type filter to prevent unwanted particulates entering the system 200. 20 10 25 The opening 201a is connected to a water holding tank 202, water passes through the opening and along a pipe to the water holding tank 202. In other examples, the rainwater collector 201 may be provided elsewhere on the cabin and there may be more than one opening or drainage channel to the holding tank. The rainwater 5 collector 201 may comprise side walls, e.g. a peripheral wall or rim, such that the rainwater collector and opening are generally inaccessible from ground level outside the cabin. Additionally or alternatively, the opening 201a to the system may be covered. io The size of water holding tank 202 is selected based on the cabin configuration, e.g. number of toilets, wash basins, taps etc. A valve or other overflow prevention arrangement could be provided, e.g. a float valve arranged to close when the level of water in the holding tank 202 reaches a predetermined maximum level. Alternatively, a simple opening can be provided to allow overspill of water outside 15 the cabin from the top of the holding tank 202 when full, or the overspill may travel out of the opening provided in the rainwater collector 201. A valve / diverter may be located in the flow path between the rainwater collector / roof and the holding tank. This may be used selectively, e.g. when 20 cleaning the roof, to ensure water from the roof does not enter the cabin water system under certain circumstances. The water holding tank may have a water level / volume sensor to detect the level of water within the holding tank. 25 The water system 200 further comprises a controller 209 arranged to receive the sensor output signal from the water level / volume sensor in the water holding tank 202 and other sensors in the water system 200. The water holding tank 202 comprises an outlet connected to a pump 203, the 30 pump 203 delivers water from the holding tank 202 to a pressurised side of the water system as will be described below. The pressurised side of the water system feeds the outlets 204 which comprise toilets, washing facilities such as sinks and showers, or taps providing drinking water. 20 10 25 The pump 203 is connected to the controller 209 such that the controller controls the operation of the pump 203. 5 The pump 203 pumps water from the holding tank to an accumulator 208, which in turn feeds water to the outlets 204. The pump 203 comprises an outlet connected to a series of mechanical filters 205. The pump 203 moves water from the holding tank 202 through the series of io mechanical filters 205. In other examples, the mechanical filters 205, or additional mechanical filters may be located between the opening of the rain collector and the water holding tank 202, or could be elsewhere in flow series upstream of the pump. The mechanical filters 205 remove debris from the water and may comprise a coarse filter and a fine filter. Alternatively, only one mechanical filter may be 15 provided. Located in flow series between the holding tank 202 and the accumulator is a section of the water system which comprises an ultraviolet light 206 and a flow sensor 207 both in connection with the controller 209. In this example, the flow 20 sensor 207 is used to determine when water is flowing up through the section of the water system which comprises the UV light 206. Alternatively, the flow sensor may be located elsewhere in the water system, for example in the water holding tank 202. 25 Whilst the above system has the mechanical filter(s) and UV light / filter upstream of the accumulator, it will be appreciated that they could also be provided downstream thereof, e.g. for decontaminating water upon delivery to one or more outlet from the holding (i.e. fresh water) tank. 30 A signal from the flow sensor 207 is sent to the controller 209 which activates the UV light 206 in response to the signal to disinfect the water flowing through the water system 200. Additionally or alternatively, the UV light 206 may be activated 20 10 25 when the pump 203 is activated. In some embodiments the flow sensor could be removed and the operation of the pump could be used as a proxy for sensing flow. During activation the UV light 206 may be constant or it may flash at a rate 5 suitable to disinfect the water flowing through the system. There may be a plurality of UV lights 206 provided, which may be provided in a row or they may be provided intermittently through a section of the water system 200. The pump may be operated by the controller at a rate suitable to maintain a flow io rate that is capable of being disinfected by the UV light. If the flow detected by the flow sensor 207 is such that the water flowing through the section of the system with the UV light 206 would not be adequately exposed to the light 206 to be decontaminated, the controller reduces the flow by slowing the pump 203. 15 The controller thus controls the decontamination of the water by the UV light, i.e. in combination with the water filter(s), to ensure that water flowing into the accumulator is adequately treated. This is important because water could be held in the accumulator for extended periods of time before being delivered to the outlets, i.e. depending on the occupation of the cabin. As such, any rainwater or 20 other water sources to the water system are treated so that they are suitable for use on the cabin. However it has also been found to be problematic that water may be retained in the water system, e.g. between the holding tank and accumulator 208 for 25 extended periods of time, which may in certain circumstances result in contamination / microbes migrating towards the accumulator 208, e.g. potentially entering the accumulator when use of the water system is resumed. In addition to the UV light 206 being activated when water is flowing, the UV light 30 206 is also intermittently activated at routine intervals when the water is not flowing. When the flow sensor 207 detects no flow of water though the system for a prolonged period of time, e.g., thirty minutes, the controller will activate the UV light 206 at selected intervals. Intermittent activation of the UV light 206 when the 20 10 25 water is not flowing ensures the system remains sterile during periods of non-use. This is particularly beneficial in a water system used in a welfare cabin, where the periods in which there is no water flow far exceed the periods where water is flowing. 5 It is envisaged that the UV light will be activated at predetermined intervals for the duration of a period in which water is not flowing through the system. The interval in this example is thirty minutes but could be longer or shorter. The intermittent UV light activation will thus prevent any microbes passing to the accumulator. This io mode of operation is also energy efficient, i.e. reducing use of the UV light to the minimum amount needed for safe ongoing use of the system. In addition to the UV light control, gravity is also used to discourage microbial movement towards the accumulator. A vertical section of the water system is 15 specifically arranged for water flowing up through the UV filter module towards the accumulator. The water is pumped upwards through the section of the water system 200 which comprises an ultraviolet light 206. The water being pumped against gravity helps 20 ensure microbes do not travel unimpeded through the UV light 206 when the light 206 is not in operation. The section of the water system comprising the UV light 206 could be vertically disposed or angled, such that any remaining water in this section of the water system when the pump is not activated does not travel to the through the section of the water system 200 with the UV light 206 whilst the light 25 206 is not in operation. An accumulator 208 with a pressure sensor and / or switch is located above the section of the water system comprising the UV light 206. The accumulator 208 is for maintaining water pressure provided by the pump 203. The pressure 30 sensor / switch in the accumulator 208 is in connection with the controller 209. Water pumped through the system is decontaminated by the UV light 206 and pumped into the accumulator 208 to be stored at elevated pressure for delivery to the outlets 204. 20 10 25 In addition to, or instead of a pressure switch, a valve 209 (such as a passive oneway valve or actively controlled valve) may be located between the UV light 206 and the accumulator 208 to prevent backflow. 5 The accumulator provides a ready source of water under pressure to deliver to the outlets 204 on demand, i.e. when a user uses an appliance or opens a tap that creates a water demand. io The controller may monitor the pressure and / or water level in the accumulator 208. The controller may additionally monitor the water level in the holding tank 202. The controller may activate the pump according to a sensed threshold for the accumulator, thereby causing water to flow through the UV filter unit to the accumulator. As water flows, the UV light 206 in the UV filter unit is activated. 15 The controller may cease operation of the pump when the accumulator achieves a predetermined water / pressure level. This may be sensed as a cessation of flow or sensing of a back pressure at the pump for example. The pressure switch / valve of the accumulator may shut off the accumulator inlet to preserve the pressure in the 20 water system. In some examples, the pump could activate in response to a water demand at one of the outlets 204. 25 It can be seen that the water tank 202 and / or water system 200 as a whole may have a further inlet 210 so that the holding tank 202 can be filled from other sources, such as a water main or external holding tank if such other sources are available. Preferably the additional inlet 202 is located at a point in the system upstream of the filter(s) 205 and UV filter unit 206 so that water entering the 30 system from such other sources can be decontaminated as described above before passing to the accumulator. 20 10 25 The water system 200 comprises one or a plurality of pipes to carry water around the system 200, i.e. between the components of the system described above. The pipes may comprise any suitable material and may comprise any configuration suitable for the cabin layout. 5 The water system 200 is a micro-onboard system, being of a size and capacity suitable for use on a welfare cabin. The water system 200 may receive power from a grid connection or the off-grid power source of the welfare cabin, this could be any suitable means for example a diesel generator or renewably charged battery. io The water system described above may also include an optional water mains connection if it is available. Any excess water (i.e. water that cannot be adequately stored or processed) may be discarded. Typically, the system is configured such that excess water will 15 overflow the collector 201 and / or holding tank 202. In some examples, excess rainwater overflowing the holding tank could be diverted into a grey water management system, e.g. to a grey water holding tank. That water may thus be used for flushing toilets, or other uses that do not demand the use of potable water. 20 In the examples above, a grey water system is not described for conciseness. A grey water system may be provided such that water dispensed at one or more outlet 204 may be reused before entering a black water tank. Systems of the type disclosed in UK Patent 2581313 could be implemented for example. 25 The cabin has been developed to give people efficient living / working facilities on sites where there is typically no available mains water connection or where it is desirable to reduce use fresh water. The invention allows safe use of rainwater or other sources on-board a welfare cabin in a manner that is safe and is achieved in an energy-efficient manner. 30 The welfare cabin water treatment system is suitable for use on a low-energy cabin, e.g. powered by renewable energy, and, as such, the water system controller may operate in conjunction with an on-board energy management controller, e.g. being one and the same controller or in communication therewith. Thus the controller can operate in the context of an energy control hierarchy. The control system will typically monitor energy availability, e.g. monitoring a level of charge on one or more battery or other energy store on the cabin. The control 5 system may have access to a schedule of future cabin use and / or future renewable energy generation potential (e.g. by way of daylight hours or weather forecasts). The control system may thus determine an extent to which the water system operation should be prioritised within a wider energy management control scheme for the cabin. For example, the predetermined periods or duration of io operation of the UV filter could be altered by the controller in response to the wider energy management control scheme. The level of pressure required on the accumulator and / or operation of the pump could also be varied by the controller in response to wider energy management schemes. 20 10 25 15 20 10 25

Claims

1. A free-standing welfare cabin having a water system comprising: a pump for pumping water through the system;5 a UV light for decontaminating the water, the UV light being in flowcommunication with the pump and being operated under the control of a controller;a holding tank upstream of the UV light;the UV light being activated by the controller when there is a flow of water io through the system; andwherein the UV light is activated intermittently by the controller when there is no water flow.

2. The welfare cabin of claim 1, wherein the UV light is activated by the15 controller based upon operation of the pump inducing a flow of water.

3. The welfare cabin of claim 1 or 2, further comprising a flow sensor, wherein the UV light is activated by the controller according to a flow of water sensed by the flow sensor.

204. The welfare cabin of claim 1, wherein the controller operates in a first mode of operation in which the UV light is activated when there is a flow of water through the system and a second mode of operation in which the controller monitors a duration for which water is not flowing and selectively activates25 the UV light for a predetermined time in response to determining that therehas been no water flowing for a predetermined duration.

5. The welfare cabin of any preceding claim where in the controller activates the UV light after a period in which there is no water flow of at least 1030 minutes, 20 minutes or 30 minutes.

6. The welfare cabin of any preceding claim, wherein the UV light is located such that the water is flowing against gravity when passing the UV light.20 10 257. The welfare cabin of any preceding claim, wherein the UV light is provided in a UV filter unit having an inlet and outlet, wherein water is fed to the inlet from below and the UV filter unit is oriented such that the outlet is above the 5 inlet.

8. The welfare cabin of any preceding claim, further comprising an accumulator located downstream of the UV light in flow series, the accumulator arranged to supply water to outlets of the water system on io board the cabin.

9. The welfare cabin of claim 8, wherein the flow of water determined by the controller for activating the UV light is upstream of the accumulator.15 10. The welfare cabin of claim 8 or 9, wherein the accumulator comprises apressure sensor or switch.11 .The welfare cabin of claim 10, wherein the controller activates the pump to supply a flow of water to the accumulator in response to the pressure20 sensor or switch.

12. The water system of any preceding claim, further comprising a rainwater collector for providing water to the system.25 13. The water system of claim 12, further comprising an external water supplyconnection.

14. The welfare cabin of any preceding claim, wherein the holding tank comprises a water level sensor and the controller controls operation of one 30 or more component of the water system in response to the output of saidsensor.

15. The welfare cabin of any preceding claim, further comprising one or more mechanical filter.20 10 2516. The welfare cabin of claim 15, wherein the one or more mechanical filter is located upstream of the UV light and / or upstream of the holding tank.

17. The welfare cabin of any preceding claim, comprising a plurality of UV lights 5 along a section of the flow path of the water system.

18. The welfare cabin of any preceding claim, wherein the UV light flashes during a period of activation.io 19. The welfare cabin of any preceding claim, comprising a renewable energy generator for powering the water system.

20. The welfare cabin of claim 19, wherein the water system is powered via a battery.1521 .The welfare cabin of any preceding claim, comprising an occupancy sensor and the controller controls operation of one or more component of the water system based on the output of the occupancy sensor.20 22. The welfare cabin of any preceding claim, comprising an onboard energystore for supplying energy to the water system and wherein one or more component of the water system is controlled in dependence upon a level of charge of the energy store.25

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