GB2638951A

GB2638951A - Filtration Apparatus

Info

Publication number: GB2638951A
Application number: GB2402499.4A
Authority: GB
Inventors: Brett Williams Leon; Spencer Collins Matthew
Original assignee: Cranfield University
Current assignee: Cranfield University
Priority date: 2024-02-22
Filing date: 2024-02-22
Publication date: 2025-09-10
Also published as: WO2025176852A1; GB202402499D0

Abstract

A separation device 10 separates liquid-solid slurry into a predominantly liquid phase and a predominantly solid phase, using a rotatable drum 31 within a tank 11. The drum has a mesh wall 33 defining an internal drum chamber 31a. A chute 37 within the drum chamber receives predominantly solid waste from an interior of the drum wall, wherein a funnelled outlet of the chute is in communication with a solid waste outlet 13 of the tank. A liquid waste outlet 12 of the tank is in fluidic communication with an exterior of the drum wall. At least one spray nozzle 15 direct(s) a fluid spray onto the exterior of the drum wall. A human waste processing apparatus comprises: the separation device as a pre-filter, a membrane distillation unit (50, Fig. 6) and may also comprise a pyrolysis unit (64, Fig. 13). In another aspect, a filtration device for solid/liquid separation comprises a filter cartridge (51, Fig. 7), preferably with a frustoconical configuration. A conical flow director (52, Fig. 8) is positioned at an upper inlet end of the filter cartridge to direct radially outward a fluid flow onto an interior surface of the filter wall.

Description

Filtration Apparatus

Field of invention

The present invention relates to separation and in particular filtration apparatus to facilitate 20 separation of solids from liquids and in particular, although not exclusively, to filtration apparatus to filter human waste into predominantly liquid waste and predominantly solid waste.

Background

According to the World Health Organisation as reported in June 2019, around 2 billion people do not have basic sanitation facilities such as toilets or latrines. Of these, an estimated 673 million defecate in the open, for example in street gutters, behind bushes or into open bodies of water. Poor sanitation is linked to transmission of diseases such as cholera, diarrhoea, dysentery, hepatitis A, typhoid and polio. In particular, inadequate sanitation, is estimated to cause around 432k diarrhoea deaths annually. Additionally, poor sanitation has been proven to reduce human wellbeing and social and economic development.

Additionally, the use of pit latrines is extensive in countries that do not have adequate sewage infrastructures. These latrines typically involve digging a deep pit that provides a waste deposit for small communities. The pit is typically covered by a platform having a suitable hole through which an individual's waste is deposited. The pit latrine continues in use until it reaches capacity. The waste should then be extracted and disposed of sustainably. However, in many countries across the world, the waste is typically extracted 10 and discharged untreated into a local river or other water course.

Attempts to address the various problems associated with no or little sewage infrastructure has included with the use of non-flushing or chemical toilets and that may be conveniently supplied and installed in remote and rural communities. It is generally required that such toilets be environmentally friendly, can be easily maintained and require low energy consumption.

Non-flushing toilets have existed for many years including for example incinerator toilets as described within US 3,020,559 and US 3,230,913. These types of toilet use a coiled electrical heating element to incinerate/burn the faeces with all emitted gases and smoke exhausted via ducts into the surrounding environment. Whilst such devices are effective to kill bacteria and other pathogens within the faeces, they are typically very energy intensive and generate harmful NOX and SOX gases (together with carbon dioxide) that are released into the surrounding environment.

Chemical toilets collect human excreta in holding tank and use chemicals to minimise odours and in some cases initiate chemical breakdown of the excreta to inhibit the growth of harmful bacteria and pathogens. However, such toilets typically require large holding tanks and significant volumes of disinfectant and deodorising chemicals. Biocides, alcohols and ammonium-based compounds are typically used. However, the collected and chemically treated waste is required to be transported to large-scale sewage processing plants before it can be discharged safely and preferably utilised for applications such as within fertilisers.

Accordingly, there is a need for improved apparatus and methods for the safe, effective and 5 environmentally sustainable collection and treatment of human waste particularly in deprived regions with poor sanitation facilities and connection to sewage treatment networks.

Summary of the Invention

It is an objective of the present concept to provide filtration apparatus to separate a mixed liquid-solid slurry into predominantly solid and predominantly liquid forms. It is a further specific objective to provide filtration apparatus for the processing of human waste in slurry form being a mixture of solid and liquid waste (faeces and urine) according to environmentally sustainable, effective and convenient pathways. It is a further specific objective to provide human waste filtration apparatus and a system to process human waste and in particular a slurry form of human waste via an energy efficient and environmentally sustainable process.

The objectives are achieved via apparatus and method that utilise a separation/filtration assembly capable of receiving a fluid being a liquid-solid mix (i.e., a slurry) at an inlet and separating the slurry into predominantly liquid and predominantly solid forms optionally via a mechanised, actuating or static filtration arrangement that utilises a minimised volume of additional liquid (in order for normal/maintained operation) such as a source of fresh liquid and/or a source of partially processed, pre-treated or pre-filtered liquid.

The present apparatus and method may comprise an actuating filtration drum having a drum internal chamber into which is delivered mixed a liquid-solid slurry wherein the drum walls comprise a mesh (or similar liquid permeable material) such that a predominantly solid phase is retained within the drum internal chamber whilst a predominantly liquid phase is allowed to pass through the drum wall as a means of separation.

According to certain aspects, the separation apparatus may comprise a generally static or non-actuating filtration mechanism in particular, according to such arrangements, the filtration device may comprise a funnel-shaped mesh screen or curved filtration wall defining an internal chamber into which is delivered a mixed liquid-solid slurry. Separation of a predominantly solid from/phase and a predominantly liquid form/phase is similarly provided via the mesh screen wail and the capability of the predominantly liquid phase to pass/flow through the liquid permeable/transmissible wall.

The present filtration/separation apparatus is capable of connection and/or integration within human solid-liquid waste processing systems and arrangements that include paralysis or torrefaction apparatus and processes and/or membrane distillation processes and/or apparatus. In particular, the present filtration apparatus may be integrated, optionally via a modular installation configuration, within a static or mobile human waste processing module having a pyrolysis/torrefaction unit and a membrane distillation unit. In particular, a pyrolysis device is connectable to the predominantly solid phase outlet of the present separation/filtration device. Additionally, membrane distillation apparatus is connectable to the predominantly liquid phase outlet of the present separation/filtration device.

The pyrolysis apparatus and process according to aspects of the present concept is configured to thermally decompose solid waste and to effectively eliminate pathogens and bacteria within faeces so as to generate a safe and biologically benign product char that may be disposed of conveniently and/or used for one or more applications. Preferably, the present pyrolysis system is configured for torrefaction processing to convert generally solid biomass into a product char via a mild form of pyrolysis involving heating temperatures optionally between 200°C to 350°C. Such a configuration is beneficial to kill pathogens and bacteria within the biomass without releasing harmful product gases such as NOX and SOX pollutants directly into the environment. The present torrefaction thermochemical treatment apparatus and method is conveniently operational at atmospheric pressure and utilises an oxygen depleted environment that is convenient and energy efficient to create and maintain.

It is a further specific objective to provide a toilet and/or human waste processing system and apparatus to process human liquid waste to filter and to remove solid matter and solid particulates optionally in addition to toxins and bacteria so as to generate a processed liquid suitable for further applications such as hand washing, toilet flushing, crop irrigation etc. These objectives are achieved via the predominantly liquid processing assembly and system that utilises a variety of sequential staged filter treatment processes and units adapted specifically to separate sequentially solid matter from liquid waste. The present liquid processing assembly and system is configured specifically to require little or zero flushing water and/or additional liquids and chemicals as part of the filtration process. In particular, the present liquid processing assembly and system utilises liquid processing loops for the efficient use of liquid and additional materials and apparatus. The present assembly and system is designed specifically to minimise the number of working components and to facilitate transport to remote locations and for installation and use within confined spaces. Moreover, the present system attempts to minimise the use of chemicals and material that are not suitable for recycling or further uses. Membrane distillation according to the present system is advantageous to separate non-volatile components, such as ions, macro-molecules and colloidal particles from a condensate liquid generated by the distillation-condensation cycle and the water-repelling nature of the membrane.

Reference within the specification to 'permeate ' encompasses a liquid that is the result of vapourisation and condensation via a membrane distillation unit. Such a term includes a condensate, a vapour, a gas, a product and the condensation of vapour or a gas within or outside the membrane module/unit. Preferably, the apparatus comprises a holding tank positioned in a fluid flow direction between the pre-filter treatment unit and the membrane distillation unit. Preferably, the apparatus comprises a first distillation flow pump to drive a flow of liquid from the holding tank to the membrane distillation unit. Preferably, the apparatus further comprises a permeate collection reservoir to collect liquid permeate output from the permeate flow outlet.

Preferably, the membrane distillation unit further comprises a permeate flow inlet connected in fluid flow with the permeate flow outlet to provide a permeate flow loop through the filter membrane. Preferably, the apparatus further comprises a second distillation flow pump connected in fluid flow with the permeate flow loop. Preferably, the apparatus further comprises a permeate output filter connected in fluid communication to an outlet of the permeate collection reservoir to receive and collect output from the membrane distillation unit.

Preferably, the apparatus comprise at least one conduit network coupled to the membrane distillation unit to provide a feed loop conduit/manifold having a feed loop inlet and a feed loop outlet at respective regions and connected in fluid communication to the membrane distillation unit. Optionally, the feed loop conduit/manifold is connected to the holding tank positioned between the pre-filter treatment unit and the membrane distillation unit. Preferably, the feed loop conduit/manifold comprises a pump. Preferably, the feed loop conduit/manifold comprises a heater. Preferably, the pump and heater of the feed loop conduit/manifold are positioned in a fluid flow direction up-stream of a feed inlet at the membrane distillation unit. Preferably, the holding tank is positioned in a fluid flow direction upstream of the pump and/or the heater. Preferably, the feed loop conduit/manifold comprises an outlet to provide an outflow/purge of liquid. Preferably, the outlet conduit of the feed loop is positioned in a fluid flow direction between the pump or heater and the membrane distillation unit. Preferably, the outlet conduit is connected to a waste collection tank. Preferably, the feed loop conduit/manifold comprises one or a plurality of valves, sensors, heaters and/or pumps.

Preferably, the apparatus comprises a permeate feed loop conduit/manifold coupled in fluid flow communication with the membrane distillation unit. Preferably, the permeate flow loop conduit/manifold comprises at least one pump, at least one condenser and/or at least one permeate holding tank. Preferably, an outlet of the permeate flow loop/conduit at the membrane distillation unit is connected in fluid communication with a condenser and an inlet of the permeate flow loop conduit/manifold at the membrane distillation unit is connected in fluid communication to the pump. Preferably, the permeate holding tank is positioned in a fluid flow direction between the condenser and the pump. Preferably, the holding tank comprises an overflow liquid outlet. Preferably, the overflow liquid outlet comprises a weir arrangement. Preferably, the outlet of the permeate holding tank is connected in fluid communication to a storage tank and/or output of the apparatus. Preferably, a filter (for example a carbon filter) is connected in fluid communication with the permeate holding tank so as to receive an outflow of liquid from the permeate holding tank and to filter the liquid to remove odours and/or any pathogens, bacteria, microbes etc. Optionally, the filter at this polishing step comprises an antimicrobial compound. Optionally, the filter at the polishing step comprises silver and/or activated granular carbon.

Reference within the specification to a mesh or mesh screen encompass components and a configuration to enable a through-flow of a predominantly liquid phase or slurry (having fines suspended solid particles) whilst retaining a predominantly solid phase at a first side of the mesh or screen. Such a term encompasses configurations including a wall or screen having perforations, a liquid permeable membrane, a net, a web, a fabric or a textile. Preferably, the pre-filter treatment unit comprises: a first pre-filter treatment unit having a first pre-filter storage tank and a first particulate filter. Optionally, the pre-filter treatment unit comprises a second pre-filter treatment unit having a second pre-filter storage tank and a second particulate filter. Optionally, the pre-filter treatment unit comprises a plurality of particulate such as in the range 2 to 4, 2 to 6 filters. Optionally, the filters may comprise the same and/or different sized filtration meshes/membranes. Optionally, the pre-filter treatment unit comprises a first particulate filter that comprises a first mesh pore size; and a second particulate filter that comprises a second mesh pore size being less than the first mesh pore size. Optionally, the pore size of the first and second filters may be approximately the same. Optionally, the first particulate filter comprises a mesh pore size in a range 50 to 800 pin, 50 to 150 [oil or 80 to 120 pm; and the second particulate filter comprises a mesh pore size in a range 0.5 to 50 pm, 0.5 to 20 pm, 0.5 to 10 pm or 0.5 to 5 pm. Reference within the specification to 'mesh pore size' refers to the size of each aperture or opening of the mesh according to conventional standards ISO 565:1990 and ISO 3310-1:2000 and EN 933-1.

According to a first aspect of the present concept there is provided a separation device to separate solid and liquid human waste comprising: a tank having an internal main chamber, a primary waste inlet, a predominantly solid waste outlet and a predominantly liquid waste outlet; a drum rotatably mounted within the main chamber having a mesh drum wall defining an internal drum chamber, a drum chamber inlet in fluidic communication with the primary waste inlet and a drum chamber outlet in fluidic communication with the predominantly solid waste outlet, the predominantly liquid waste outlet in fluidic communication with an exterior of the drum wall; a chute mounted within the drum chamber and having an opening to receive predominantly sold waste from an interior of the drum wall and a funnelled outlet in communication with the predominantly solid waste outlet; and at least one spray nozzle positioned opposed to the exterior of the drum wall and configured to direct a fluid spray onto the exterior of the drum wall.

Optionally, the chute is statically mounted within the drum chamber to be stationary 15 relative to a rotation of the drum.

Optionally, the tank comprises an internal sub chamber at least partially partitioned from the main chamber, the sub chamber in fluidic communication with the primary waste inlet. Optionally, the sub chamber comprises an inclined base surface that slopes downwardly to terminate at one side at the drum chamber inlet. Optionally, the sub chamber is provided in direct fluidic communication with the primary waste inlet. Optionally, the main chamber is provided in indirect fluidic communication with the primary waste inlet via the sub chamber.

Optionally, the predominantly liquid waste outlet is positioned below the drum, and the tank comprises a liquid outflow guide surface to direct a flow of predominantly liquid waste received through the drum wall to the predominantly liquid waste outlet. Optionally, the liquid outflow guide surface is concave of V-shaped to define a gulley or channel provided in direct fluidic communication with the predominantly liquid waste outlet.

Optionally, the device further comprises a drive actuator and a motor to drive a rotation of the drum about a central rotational axis. Optionally, the drive actuator comprises a toothed gear and/or belt drive mechanism or arrangement at least partially coupling the drum and the motor.

Optionally, the device further comprises at least one sensor mounted within the chamber to 5 monitor a volume or level of waste within the chamber.

Optionally, the waste inlet comprises an inlet valve. Optionally, the device comprises a multi-port valve connected in fluidic communication with the predominantly solid waste outlet, the multi-port valve having at least three fluid flow ports.

Optionally, the device further comprises a source of a gas (e.g., air) provided in fluidic communication with the at least one nozzle to enable a spray of the gas (e.g., air) onto the exterior of the drum wall via the at least one nozzle Optionally, the device further comprises a gas pump to drive a transfer of the gas (e.g., air) to the at least one spray nozzle. Optionally, the device comprises a liquid source connected in fluidic communication with the at least one spray nozzle to enable a spray of liquid onto the exterior of the drum wall via the at least one spray nozzle. Optionally, the device comprises at least one mixer valve connecting the at least one spray nozzle and the source of gas (e.g., compressed air tank) and liquid to enable a mixed gas and liquid spray onto the exterior of the drum wall. According to the present concept, the use of a gas such as compressed air as a back-washing medium for the drum based filter is advantages. In particular, this minimises both the use of processed clean water, e.g., from a toilet (a limited resource of typically 5L) and avoids adding excessive volumes of backwash water to the present filtration unit. The present concept is adapted also for water flushing/backwashing in addition to gas/air washing. Optionally, such water washing may be minimised and used to provide a final rinse only as required. The chamber of the present filtration unit is important to provide there are no 'dead spaces' for faecal contaminated liquid to remain and thus contaminate incoming and outgoing streams (especially if urination only inputs are more frequent).

Optionally, the device further comprises a control module provided in electronic communication with any one or a combination of the following components: the sensor; the inlet valve; the multi-port valve; the gas pump; the drive actuator and/or the motor connected to the drum; the mixer valve; to enable remote electronic control of any one or a combination of said components. Optionally, the device further comprises a plurality of electromagnetic and/or electronic control components provided at or coupled to any one or a combination of said components to provide electronic control of any one or a combination of said components. Optionally, the control module is connected to the sensor and the drive actuator and/or the motor of the drum to control actuation and/or rotation of the drum about the axis in response to a signal from the sensor that a volume or level of waste within the chamber is at predefined amount.

The configuration of the inlets and outlets of the present actuating/rotating drum-based filtration devices as described herein is advantageous to eliminate any Vead-zones' within the device and avoid contamination build-up. In particular, the shape of the present chamber and/or the centralised input/backwashed output ports provides that the present concept does not require a manual maintenance cycle and is self-cleaning.

According to a further aspect of the present concept there is provided human waste processing apparatus comprising: a) a predominantly liquid waste processing assembly comprising: at least one pre-filter treatment unit comprising a separation device to separate solid and liquid human waste as described claimed herein; a membrane distillation unit having a membrane distillation vessel with an internal filter membrane, a primary flow liquid inlet and outlet and a permeate flow outlet, the primary flow liquid inlet connected in fluidic communication to the predominantly liquid waste outlet of the separation device; and at least one flow actuator to drive a flow of waste liquid through the pre-filter treatment unit and in a flow direction towards the membrane distillation unit.

Optionally, the apparatus further comprises at least one pre-filter treatment unit comprising a first separation device to separate solid and liquid human waste, the first separation device comprising: a tank having an internal main chamber, a primary waste inlet, a predominantly solid waste outlet and a predominantly liquid waste outlet; a drum rotatably mounted within the main chamber having a mesh drum wall defining an internal drum chamber, a drum chamber inlet in fluidic communication with the primary waste inlet and a drum chamber outlet in fluidic communication with the predominantly solid waste outlet, the predominantly liquid waste outlet in fluidic communication with an exterior of the drum wall; a chute mounted within the drum chamber and having an opening to receive predominantly sold waste from an interior of the drum wall and a funnelled outlet in communication with the predominantly solid waste outlet; and at least one spray nozzle positioned opposed to the exterior of the drum wall and configured to direct a fluid spray onto the exterior of the drum wall; and a second separation device to separate solid and liquid human waste, the second separation device connected in fluid communication with the first separation device and comprising: a funnel-shaped mesh screen having a curved filtration wall extending around a longitudinal axis of the filtration device and between axial inlet and outlet ends; a flow director configured to receive a flow of a liquid-solid slurry, the flow director having a cone-shaped flow guide surface that tapers radially outward from a leading to a trailing axial end; the flow director positioned on the longitudinal axis at or towards the axial inlet end of the mesh screen to direct radially outward a flow of a fluid onto an interior surface of the mesh screen.

Optionally, the apparatus further comprises: b) a solid waste processing assembly comprising: a pyrolysis unit having at least one heater and a pyrolysis chamber provided with a solid waste inlet, a solid waste outlet, a gas/moisture vapour outlet, the solid waste inlet provided in fluidic communication with the predominantly solid waste outlet of the separation device; and a scrubber unit having a scrubber tank to contain a scrubber liquid and provided with a liquid outlet, a gas outlet and a gas/moisture vapour inlet coupled to the gas/moisture vapour outlet of the pyrolysis chamber.

Optionally, the apparatus comprises a plurality of pre-filter treatment unit comprising a separation device to separate solid and liquid human waste as claimed herein, the separation devices arranged in-series in a fluid flow direction through the apparatus. Optionally the apparatus comprises 2 to 10, 2 to 8, 2 to 6, 2, 3 or 4 devices arranged and connected in fluid communication in-series. Optionally the separation devices are identical/the same. Optionally, the apparatus may comprise at least two different types of separation device as described herein including a mechanised/actuating drum filter-type arrangement and a funnel-shaped mesh screen type arrangement as described herein.

Optionally, the apparatus comprises: a toilet or human waste receiving device having a toilet outlet coupled to the primary waste inlet of the separation device as claimed herein.

Optionally, the apparatus further comprises a mixed waste actuator to transport and/or at least partially separate the solid and liquid waste, the actuator positioned in a waste flow direction between the toilet outlet and primary waste inlet of the separation device.

According to further aspect of the present concept there is provided a filtration device for solid and liquid separation comprising: a funnel-shaped mesh screen having a curved filtration wall extending around a longitudinal axis of the filtration device and between axial inlet and outlet ends; a flow director configured to receive a flow of a liquid-solid slurry, the flow director having a cone-shaped flow guide surface that tapers radially outward from a leading to a trailing axial end; the flow director positioned on the longitudinal axis at or towards the axial inlet end of the mesh screen to direct radially outward a flow of a fluid onto an interior surface of the mesh screen.

Optionally, the mesh screen is frusto-conical. Optionally, the flow director is conical or frusto-conical. Optionally, the device comprises a head collar releasably attachable to the 20 leading axial inlet end of the mesh screen, the flow director mounted at the collar via radial spokes.

Optionally, the trailing axial end of the flow director is axially separated from the axial inlet end of the mesh screen by an axial thickness of the collar. Optionally, the head comprises a first mount for attachment to a fluid supply conduit to enable a supply flow of a slurry to the mesh screen.

Optionally, the device further comprises a frame attachable and configured to positionally support the mesh screen. Optionally, the frame comprises a radially inner frame part and a radially outer frame part, the mesh screen capable of being contained radially intermediate the inner and outer frame parts. Optionally, the frame comprises a second mount for attachment to a flow outlet conduit.

According to a further aspect of the present concept there is provided fluid filtration apparatus for solid and liquid separation comprising: the filtration device as claimed herein; and a tank having an internal chamber, the filtration device housed within the 5 internal chamber.

Optionally, the apparatus comprises a multi-port valve connectable in fluidic communication with the outlet end of the mesh screen or a flow outlet conduit attached to the outlet end. Optionally, the valve comprises at least one electromagnetic and/or electronic control component to enable electronic control of the valve.

Optionally, the apparatus comprises at least one sensor mounted within the internal chamber of the tank and/or mounted at the mesh screen to monitor a volume and/or a level of slurry or liquid within the tank.

Optionally, the apparatus comprises a control module provided in electronic communication with the sensor, the control module comprising hardware and/or software.

Optionally, the control module is provided in electronic communication with the electromagnetic and/or electronic control component such that the control module is configured to control operation of the multi-port valve to direct a flow of fluid from the separation device to one of a plurality of fluid flow conduits provided in fluidic communication with the multi-port valve.

Brief description of drawings

A specific implementation of the present invention will now be described, by way of example only, and with reference to the accompanying drawings in which: Figure 1 is a side view of a liquid-solid slurry separation device according to a specific implementation of the present concept; Figure 2 is a perspective side view of the separation device of figure 1; Figure 3 is a cross sectional perspective view through the device of figure 2; Figure 4 is a perspective view of a chute mounted within a rotatable drum within the separation device of figure 3; Figure 5 is a perspective view of a rotatable drum mounted within the separation device of figure 3; Figure 6 is a perspective view of selected components of human waste processing apparatus having a plurality of separation devices of figure 3 in processing communication with a variety of other components forming part of the apparatus according to a specific implementation of the present concept; Figure 7 is a perspective view of a liquid-solid separator device according to a further specific implementation connectable to other components of human waste processing apparatus; Figure 8 is a cross sectional perspective view of the separator device of figure 7; Figure 9 is a cross sectional perspective view of a filter cartridge forming part of the separation device of figure 8; Figure 10 is an upper perspective view of the filter cartridge of figure 9; Figure 11 is a schematic illustration of a separation device of figure 3 coupled to a separation device of figure 7 connected in-series according to a combined pre-filtration arrangement according to a specific implementation of the present concept; Figure 12 is a schematic illustration of a pair of separation devices of figure 7 connected in-series forming part of a pre-filtration arrangement according to a specific implementation of the present concept; Figure 13 is a perspective view of a modular waste processing system configured for processing human waste according to a specific implementation of the present concept; Figure 14 is a perspective view of a pyrolysis/torrefaction processing unit configured for processing predominantly solid phase matter according to a specific implementation of the 10 present concept.

Detailed description of preferred embodiment of the invention Referring to figure 1, a liquid-solid separation device 10 comprises a tank 11, a predominantly solid phase outlet 13 and a predominantly liquid phase outlet 12. A plurality of spray nozzles 15 are mounted at an upper region (i.e., a roof) of the tank 11 relative to the predominantly liquid phase outlet 12 that is located at a lower or base region of the tank 11. Referring to figures 2 and 3, tank 11 defines an internal chamber 25 that, according to the specific implementation is partitioned internally via partition wall 26 into a primary or main chamber 25a and a secondary or sub chamber 25b (corresponding to primary tank portion 24 and sub tank portion 23, respectively). A mixed liquid-solid slurry waste inlet 14 is provided at tank 11 specifically in fluidic communication with sub chamber 25b. A slurry volume or level sensor (in the form of a float switch 21) is mounted at tank 11 to extend internally within sub-chamber 25. Sub chamber 25 further comprises an overflow outlet 22. Tank 11, at sub chamber 25b, comprises an internal base surface 27 that is V-shaped to define a gully or channel 28 extending from a first side lla to a second side 1 lb of sub chamber 25b. A drum 31 is rotatably mounted within main chamber 25. Drum 31 comprises a generally cylindrical drum wall 32 extending between respective axial ends, each end mounted at respective bearings/rotation couplings to enable rotation of drum 31 about a drum axis 59 (figure 5) within chamber 25. Drum wall 32 is modular and comprises a multicomponent arrangement. In particular, drum wall 32 comprises a frame, rib or cage structure having openings extending through wall 32. A mesh screen (represented by reference 33) extends over and bridges the apertures of the frame to define a predominantly liquid phase permeably/transmissible wall of drum 31. The cylindrical drum wall 32 comprises an internal facing surface 34 and an external facing surface 35. Internal facing surface 34, in part, defines a drum interior 31a. A conduit 36 in the form of a bore or opening extends through partition 26 to provide fluidic communication between sub chamber 25b and drum interior 31a. In particular, conduit 36 is positioned at sub chamber end l lb and aligned with channel 28, at the lower end of the inclined base surface 27. Accordingly, liquid-solid slurry is encouraged to flow under gravity downwardly over base surface 27 and then directly into drum interior 31a.

Referring to figures 3 and 4, a chute 37 is mounted statically within drum interior 31a. Chute 37 comprises an enlarged open end 37a capable of receiving predominantly solid phase matter into an interior of chute 37. Chute 37 further comprises a predominantly solid phase outlet 37b. A curved or funnel shaped section 37c extends between the respective open end 37a and outlet 37b to encourage predominantly solid phase matter to flow/fall under gravity from open end 37a to outlet 37b. Chute 37 is mounted statically within chamber 25 and preferably mounted to a wall region of tank 11 at or towards the predominantly solid phase outlet 13. In particular, chute outlet 37b is provided in fluidic communication with tank outlet 13 such that predominantly solid phase matter is able to flow from the drum interior 31a through the tank wall and out of the separation device 10 via the predominantly solid phase outlet 13. Suitable bearings and couplings (not shown) provide a mounting of the chute 37 relative to drum 31 to enable drum 31 to rotate whilst chute 37 remains static/stational), within drum interior 31a. According to the specific configuration, chute open end 37c is maintained at an elevated upper region of drum interior 31a. In particular, open end 37a is positioned opposed to drum interion face 37 and opposed to a roof or upper face of tank 11 relative to a lower or base side of tank 11 corresponding to the location of the predominantly liquid phase outlet 12.

Tank 11 at main chamber 25a comprises a lower or base internal surface 29 positioned opposed to the exterior surface 35 of drum wall 32. Surface 29 is declined between a first side 11c and a second lower side 11 d with the predominantly liquid phase outlet 12 collocated at second side 11d. The lower or base region of tank 11 at main chamber 25a is V-shaped so as to define a channel or gully 30 extending between surface sides 11c, lld. Accordingly, predominantly liquid phase matter within main chamber 25 is encouraged to flow under gravity downwardly over surface 29 and along channel 30 towards the outlet 12.

Referring to figures 3 and 5, spray nozzles 15 arc mounted at the roof or upper region of tank 11 and extend into main chamber 25. In particular, a pair of spray nozzles 15 comprise terminal ends that are positioned opposed to the exterior face 37 of the drum wall 32. Spray nozzles 15 are each configured to dispense a spray of a fluid (gas and/or liquid phase) onto drum exterior surface 35 as drum 31 is rotated within chamber 25.

Rotation of drum 31 is provided by a mechanical actuator arrangement according to the specific implementation comprising a toothed primary gear 38 coaxial with drum 31 and extending about drum longitudinal axis 59. Primary gear 39 comprises a central aperture 41 for collocating around conduit 36. A toothed drive gear 39 is mounted in inter-engaging operation with main gear 38 and drivably coupled to a motor 40. Accordingly, actuation of motor 40 provides a corresponding rotation of drive gear 39, a corresponding rotation of primary gear 38 and a corresponding rotation of drum 31 about axis 59.

Referring to figure 6, the separation device 10 of figures 1 to 5 is capable of being installed within human waste processing apparatus as a modular pre-filtration assembly. In particular, a plurality of separation devices 10 are mounted in a waste processing fluid direction in-series such that waste flows through a first separation device 10a and then through a second separation device lob. Each device 10a, 106 may comprise a drum wall 32 having a mesh 33 with a different respective mesh size. For example, a first device 10a may comprise a 10 to 50 nm, optionally 25pm mesh, whilst second device 10b may comprise a finer/smaller mesh of e.g. 100 to 250 nm. In particular, according to the in-series arrangement of figure 6, the predominantly liquid phase outlet 12 of first separation device 10 is coupled to inlet 14 of the second separator device 10. The predominantly solid phase outlets 13 are coupled to a downstream predominantly solid phase processing module that comprises a pyrolysis/torrefaction unit 65 (figure 14). According to the specific implementation, the predominantly liquid phase outlet 12 of the second separation device 10b may be coupled in fluidic communication with a downstream predominantly liquid phase treatment module optionally in the form of a membrane distillation unit 50. The separation devices 10a, 10b may be coupled to the respective pyrolysis/torrefaction and membrane distillation units 65, 50 via intermediate holding tanks 48, 49 respectively, with all unis and modules coupled via connecting conduits as illustrated in figure 6.

Each separation device 10a, 10b and in particular spray nozzles 15 are connected in fluidic communication to a gas source 44 via a regulator 46. A flow of gas from source 44 is supplied to nozzles 15 via pump 45 and respective connecting conduits 47.

Each separation device 10, 10a, 10b comprises a respective sensor 21. Additionally, each device 10, 10a, 10b may comprise further sensors (not shown) positioned at any one or a combination of main chamber 25a, sub chamber 25b, drum interior 31a, outlets 12, 13 and inlet 14. Each separation device 10, 10a, 10b is connectable to a control unit 42 via a suitable electronic wiring/connection 43. According to one mode of operation, sensor 21 (implemented as a float switch) may be triggered when a volume of liquid/solid slurry within sub chamber 25a reaches a predetermined level. Control unit 42 is configured to actuate drive motor 40 and a rotation of drum 31 within chamber 25 whilst terminating flow of a slurry into sub chamber 25 via inlet 14. In particular, according to preferred embodiments, an inlet valve (not shown) is provided at inlet 14 optionally in the form of an electromagnetic or electronically controllable valve. Similar electromagnetic and/or electronically controllable valves (not shown) may be provided at outlets 12 and/or 13.

Referring to figure 2, the nozzles 15 are connected to gas source 44 via a mixer valve 16 having a first supply conduit 20 and control valve 18 to receive the fluidic transfer of gas from gas source 44. Mixer valve 16 is also coupled to liquid supply conduit 19 connected to a further control valve 17. Conduit 19 is connectable to a liquid supply source (not shown). Optionally, liquid supply conduit 19 may be coupled to predominantly liquid phase storage tank 49 that contains the predominantly liquid phase that has been pre-filtered by the separation devices 10a, 10b according to the in-series arrangement of figure 6. Accordingly, spray nozzles 15 are configured to supply a spray onto the exterior surface of drum wall 32 in the form of a gas, a liquid and/or a mixed gas-liquid phase via supply conduits 20, 19. Control unit 42 is electronically/electrically connected to the plurality of different valves within the apparatus including in particular separation device so as to control each and all valves and mechanical actuators as described.

Accordingly, a fully automated apparatus is provided to filter and process liquid-solid 5 phase slurries and to separate a predominantly liquid phase from a predominantly solid phase via an automated process as described.

A further embodiment of the separation device 10 is illustrated in figure 7. The separation device 10 comprises a tank 11 having internal chamber 25 which, unlike the separation device of figures 1 to 5, is not separated into a main and sub chamber. A filter cartridge indicated generally by reference 51 is removably mounted within tank chamber 25. A predominantly liquid phase outlet 12 is coupled to a lower region or base surface of tank 11 and a predominantly solid phase outlet 13 is similarly coupled to the lower or base surface of tank 11 coaxial with filter cartridge 51. A liquid-solid slurry inlet 14 is provided 15 at tank 11 and is coupled to a roof or upper region of tank 11 in fluidic communication with filter cartridge 51.

Referring to figures 8 to 10, filter cartridge 51 comprises a frusto conical configuration having a cone-shaped main filter wall extending axially between a first (upper) axial end 51a and a second (lower) axial end 51b. The cone walls 54 are formed from a radially outer frame part 55, a radially inner frame part 56 and a mesh 53 trapped/positioned radially between the respective outer and inner frame parts 55, 56. Each of the frame parts 55, 56 and mesh 53 extend longitudinally between cartridge axial ends 51a, 51b. The cartridge cone is radially enlarged at inlet end 51a relative to outlet end 51b. Accordingly, the cone walls 54 taper radially inward from end 51a to 51b. Each of the outer and inner frame parts 55, 56 comprise a skeletal, caged or grid type structure having openings over which extend the intermediate mesh 53 (in a similar/corresponding arrangement to the embodiment of figures 1 to 5). The conical filter walls 54 accordingly define a filtration inner chamber extending axially between ends 51a, 51b.

A flow director in the form of a conical body 52 is positioned at cone inlet end 51a Conical body 52 is located on the central longitudinal axis of filter cartridge 51 and is mounted in static position centrally at the inlet end 51a via radial spokes 56 that extend radially between an annular collar 57, that defines the opening of inlet end 51a, and the flow director 52. According to a specific implementation, three spokes 56 are provided and are uniformly spaced in a circumferential direction around the director 52. Director 52 comprises an enlarged diameter trailing end 52b and a pointed leading axial end 52a (relative to a fluid flow direction through the cartridge 51). The cone shaped director 52 is arranged opposed to the liquid-solid slurry flow direction so as to present a radially increasing body between ends 52a, 52b. This is in contrast to the filtration cartridge 51 having a cone shape in which the diameter of the cone decreases from input end 51a to output end 51b. Filter cartridge 51 is held in place at tank 11 via an input coupling in the form of a cap. The cap comprises an outer locking collar 200 having screw threads 207 to cooperate with corresponding threads provided at an annular locating flange 204 at tank 11. Locking collar 200 is configured to engage with an inner mounting collar 203 having corresponding screw threads 202 to cooperate with an inner mounting 208 that together form an attachment to secure filter cartridge 51 at the axial inlet end 51a. A corresponding axial tube 205 projects axially from filter outlet end 5 lb to sit within a housing 206 provided at and/or partially defining the predominantly solid phase outlet 13. Accordingly, filtration cartridge 51 is removably mountable/attachable at tank 11 via the respective mountings at axial ends 51a, 51b as described and illustrated according to figures 8 and 9.

In use, a slurry of liquid-solid phase matter is introduced into the inner chamber of filtration cartridge 51 via inlet 14. The slurry contacts director 52 and is deflected radially outward onto an interior surface of the cone walls 54 (that define the internal cartridge chamber). Predominantly solid phase matter is at least partially retained by mesh 53 and prevented from passage through the filter walls 54. Predominantly liquid phase matter is capable of flowing through the mesh/filter walls 54 to flood chamber 25. As the liquid-solid slurry continues to flow into filtration cartridge 51, the predominantly solid phase is encouraged to fall under gravity axially from inlet end 51a to outlet end 51b and to exit cartridge 51 via the predominantly solid phase outlet 13. The predominantly liquid phase captured within chamber 25 is then allowed to exit via predominantly liquid phase outlet 12. Director 52 is advantageous to deflect the predominantly solid phase matter onto the cartridge internal wall surface where it is at least partially retained and encouraged/channelled to travel under gravity axially downward towards outlet 13. The opposed conical arrangement of director 52 and main cone body of filter 51 has been found to facilitate liquid and solid phase separation.

Referring to figure 11, a combined filtration/separation assembly is provided comprising an in-series arrangement of separation devices 10a, 10b (to form part of a modular processing system as described referring to figure 6. According to the embodiment of figure 11, the arrangement comprises a first separator 10a comprising the components and function described referring to figures 1 to 5 and a second separation device 10b corresponding to the embodiment of figures 7 to 10. As illustrated, first separation device 10a is connected in fluidic communication with the second device 10b via conduit 58 extending between outlet 12 and inlet 14 of the respective devices 10a, 10b. To ensure delivery of liquid/slurry to the second device 10b at sufficient pressure, a pump 72 is connected to the conduit 58 to pressurize the liquid as it is transferred between devices 10a and 10b. Pump 72 may be controlled via suitable electronic control 42 (figure 6) and may be connect to other components described herein. The multi-port predominantly solid phase outlet 13 comprises a first outlet port 13a and second outlet port 13b, each configured to provide a flow of matter to an appropriate downstream location such as a solid phase processing unit e.g. pyrolizer/torrefaction unit 65 (figure 14) and/or intermediate storage tank 48 for onward transport and supply to corresponding downstream processing utilities.

Figure 12 illustrates a further embodiment of an in-series arrangement of separation devices. According to the further embodiment, the separation arrangement comprises a first separation device 10a and a second separation device 10b of the type described referring to figures 7 to 10 being the internal filtration cartridge 51. Cartridge 51 within first device 10a may comprise a relatively coarser mesh 53 in a range 10 to 50 gm whilst the corresponding mesh 53 within device 10b may comprise a finer configuration with a mesh size in a range 100 to 250 gm. As with the embodiment of figure 11, fluidic communication is provided via conduit 58 extending between predominantly liquid phase outlet 12 of device 10a and the inlet 14 of device 10b.

Referring to figure 13, the separation device 10 as described herein may be integrated within a human waste processing system 61 forming a modular assembly having a frame 62 that mounts the various components. In particular, system 61 comprises a plurality of separation devices 10 that represent a pre-filtering module; a front end toilet 60; a liquid-solid waste transporter 67 extending between toilet 60 and a pyrolysis and emission scrubber module 65 (63, 64, 66,) via interconnection supply conduit 68. Separation devices 10 are also coupled to a predominantly liquid waste processing module in the form of a membrane distillation unit 50 via intermediate storage tank 49. Membrane distillation module 50 comprises associated pumps and permeate and distillate flow loops/circuits (not shown) in which predominantly liquid waste is configured to flow through a main chamber that includes a membrane where the waste is distilled via conventional membrane distillation processes to provide a distillate being accordingly separated from the permeate flow liquid as described according to the system and apparatus of WO 2022/214576 Al that is incorporated herein by reference.

Figure 14 illustrates further details of the pyrolysis/torrefaction module 65. Module 65 comprises the pyrolysis and emission scrubber configured specifically for the processing and treatment of predominantly solid waste (faeces/faecal matter). The primary components of the module 65 comprise the pyrolysis unit 64, emission scrubber 63, a char collection trap 66, a heater 69, a gas/moisture vapour conduit 71 providing fluid communication between the pyrolysis unit 64 (via gas outlet 73) and the emission scrubber 63 (via inlet 76) in addition to various inlets and outlets. The emission scrubber 215 comprises a tank for containment of a scrubbing liquid (typically water) into which is discharged directly the gas product of the pyrolysis unit 64. Both the emission scrubber 63 and the pyrolysis unit 64 are elongate having respective first upper ends and second lower ends. A char collection trap 238 is mounted to the second lower end of the pyrolysis unit 64.

The emission scrubber 63 comprises a gas/moisture vapour inlet defined generally by reference 76. Inlet 76 comprises an elongate inlet tube that extends from the first upper end towards second lower end. A lower terminal end of the tube is submerged within the scrubber liquid contained in the scrubber tank. Scrubber tank also comprises a liquid outlet positioned in a lengthwise direction tank between ends just above a mid-length position. Emission scrubber 63 also comprises a gas/moisture vapour outlet 70 located at its first upper end.

The modular arrangement of figures 13 and 14 provide a human waste treatment system in which the separator devices 10 form a component part and represent a pre-filtration module according to the system and apparatus described in WO 2022/214576 Al that is incorporated herein by reference. That is, the respective predominantly liquid and solid phase outlets of the respective separator devices 10 are connectable respectively to at least one membrane distillation unit and pyrolysis/torrefaction unit, optionally via intermediate storage tanks for the automated processing of human waste according to an initial or preseparation/filtration process followed by downstream processing of predominantly liquid phase waste (via the membrane distillation module) and predominantly solid phase waste (by the pyrolysis/torrefaction module).

According to specific implementations, the apparatus may comprise any configuration of in-series filtration devices 10 having a plurality of devices 10 corresponding to the embodiment of figures 1 to 5 and/or the embodiment of figures 7 to 10 to form an in-series interconnected multi filtration device module in which each device 10 comprises corresponding components and features whilst optionally differing in a respective size of mesh 33, 53 as described so as to provide a progressive and effective modular filtration assembly.

Claims

Claims 1. A separation device to separate solid and liquid human waste comprising: a tank having an internal main chamber, a primary waste inlet, a predominantly 5 solid waste outlet and a predominantly liquid waste outlet; a drum rotatably mounted within the main chamber having a mesh drum wall defining an internal drum chamber, a drum chamber inlet in fluidic communication with the primary waste inlet and a drum chamber outlet in fluidic communication with the predominantly solid waste outlet, the predominantly liquid waste outlet in fluidic 10 communication with an exterior of the drum wall; a chute mounted within the drum chamber and having an opening to receive predominantly sold waste from an interior of the drum wall and a funnelled outlet in communication with the predominantly solid waste outlet; and at least one spray nozzle positioned opposed to the exterior of the drum wall and configured to direct a fluid spray onto the exterior of the drum wall.
2. The device as claimed in claim 1 wherein the chute is statically mounted within the drum chamber to be stationary relative to a rotation of the drum.
3. The device as claimed in claim 1 or 2 wherein the tank comprises an internal sub chamber at least partially partitioned from the main chamber, the sub chamber in fluidic communication with the primary waste inlet.
4. The device as claimed in claim 3 wherein the sub chamber comprises an inclined 25 base surface that slopes downwardly to terminate at one side at the drum chamber inlet.
5. The device as claimed in claims 3 or 4 wherein the sub chamber s provided in direct fluidic communication with the primary waste inlet.
6. The device as claimed in any one of claims 3 to 5 wherein the main chamber is provided in indirect fluidic communication with the primary waste inlet via the sub chamber.
7. The device as claimed in any preceding claim wherein the predominantly liquid waste outlet is positioned below the drum, and the tank comprises a liquid outflow guide surface to direct a flow of predominantly liquid waste received through the drum wall to 5 the predominantly liquid waste outlet.
8. The device as claimed in claim 7 wherein the liquid outflow guide surface is concave of V-shaped to define a gulley or channel provided in direct fluidic communication with the predominantly liquid waste outlet.
9. The device as claimed in any preceding claim further comprising a drive actuator and a motor to drive a rotation of the drum about a central rotational axis.
10. The device as claimed in claim 9 wherein the drive actuator comprises a toothed 15 gear and/or belt drive mechanism or arrangement at least partially coupling the drum and the motor.
11. The device as claimed in any preceding claim further comprising at least one sensor mounted within the chamber to monitor a volume or level of waste within the 20 chamber.
12. The device as claimed in any preceding claim wherein the waste inlet comprises an inlet valve.
13. The device as claimed in any preceding claim comprising a multi-port valve connected in fluidic communication with the predominantly solid waste outlet, the multi-port valve having at least three fluid flow ports.
14. The device as claimed in any preceding claim further comprising a source of a gas provided in fluidic communication with the at least one nozzle to enable a spray of the gas onto the exterior of the drum wall via the at least one nozzle.
15. The device as claimed in claim 14 comprising a gas pump to drive a transfer of the gas to the at least one spray nozzle
16. The device as claimed in claim 14 or 15 comprising a liquid source connected in 5 fluidic communication with the at least one spray nozzle to enable a spray of liquid onto the exterior of the drum wall via the at least one spray nozzle.
17. The device as claimed in claim 16 comprising at least one mixer valve connecting the at least one spray nozzle and the source of gas and liquid to enable a mixed gas and 10 liquid spray onto the exterior of the drum wall.
18. The device as claimed in claims 9 to 17 further comprising a control module provided in electronic communication with any one or a combination of the following components: * the sensor * the inlet valve * the multi-port valve * the gas pump * the drive actuator and/or the motor connected to the drum * the mixer valve to enable remote electronic control of any one or a combination of said components.
19. The device as claimed in claim 18 further comprising a plurality of electromagnetic and/or electronic control components provided at or coupled to any one or 25 a combination of said components to provide electronic control of any one or a combination of said components.
20. The device as claimed in claims 18 or 19 wherein the control module is connected to the sensor and the drive actuator and/or the motor of the drum to control actuation 30 and/or rotation of the drum about the axis in response to a signal from the sensor that a volume or level of waste within the chamber is at predefined amount.
21. Human waste processing apparatus comprising: a) a predominantly liquid waste processing assembly comprising: at least one pre-filter treatment unit comprising a separation device to 5 separate solid and liquid human waste according to any one of claims 1 to 20; a membrane distillation unit having a membrane distillation vessel with an internal filter membrane, a primary flow liquid inlet and outlet and a permeate flow outlet, the primary flow liquid inlet connected in fluidic communication to the predominantly liquid waste outlet of the separation device; and at least one flow actuator to drive a flow of waste liquid through the pre-filter treatment unit and in a flow direction towards the membrane distillation unit.
22. The human waste processing apparatus as claimed in claim 21 further comprising: b) a solid waste processing assembly comprising: a pyrolysis unit having at least one heater and a pyrolysis chamber provided with a solid waste inlet, a solid waste outlet, a gas/moisture vapour outlet, the solid waste inlet provided in fluidic communication with the predominantly solid waste outlet of the separation device; and a scrubber unit having a scrubber tank to contain a scrubber liquid and provided with a liquid outlet, a gas outlet and a gas/moisture vapour inlet coupled to the gas/moisture vapour outlet of the pyrolysis chamber.
23. The apparatus as claimed in claim 22 comprising: a toilet or human waste receiving device having a toilet outlet coupled to the 25 primary waste inlet of the separation device according to any one of claims 1 to 20.
24. The apparatus as claimed in claim 23 further comprising a mixed waste actuator to transport and/or at least partially separate the solid and liquid waste, the actuator positioned in a waste flow direction between the toilet outlet and primary waste inlet of the 30 separation device.
25. A filtration device for solid and liquid separation comprising: a funnel-shaped mesh screen having a curved filtration wall extending around a longitudinal axis of the filtration device and between axial inlet and outlet ends; a flow director configured to receive a flow of a liquid-solid slurry, the flow director having a cone-shaped flow guide surface that tapers radially outward from a leading to a trailing axial end; the flow director positioned on the longitudinal axis at or towards the axial inlet end of the mesh screen to direct radially outward a flow of a fluid onto an interior surface 10 of the mesh screen.
26. The device as claimed in claim 25 wherein the mesh screen is frusto-conical.
27. The device as claimed in claims 25 or 26 wherein the flow director s conical or 15 frusto-conical.
28. The device as claimed in any one of claims 25 to 27 comprising a head collar releasably attachable to the leading axial inlet end of the mesh screen, the flow director mounted at the collar via radial spokes.
29. The device as claimed in claim 28 wherein the trailing axial end of the flow director is axially separated from the axial inlet end of the mesh screen by an axial thickness of the collar.
30. The device as claimed in claims 28 or 29 wherein the head comprises a first mount for attachment to a fluid supply conduit to enable a supply flow of a slurry to the mesh screen.
31. The device as claimed in any one of claims 25 to 30 further comprising a frame attachable and configured to positionally support the mesh screen.
32. The device as claimed in claim 31 wherein the frame comprises a radially inner frame part and a radially outer frame part, the mesh screen capable of being contained radially intermediate the inner and outer frame parts.
33 The device as claimed in claim 32 wherein the frame comprises a second mount for attachment to a flow outlet conduit.
34. Fluid filtration apparatus for solid and liquid separation comprising: the filtration device as claimed in any of claims 25 to 33; and a tank having an internal chamber, the filtration device housed within the internal chamber.