DOC neutralisation
Budget: $10 – $30 USD
Project Overview
I need a CAD designer to model a subsea neutralisation mixing chamber and multiport discharge diffuser system in Autodesk Fusion 360. The system is part of a Direct Ocean Capture (DOC) process that captures CO₂ from seawater.
I will also need 2–3 hand-drawn style conceptual design sketches (annotated diagrams showing the system layout, flow path, and key components) that look like engineering concept sketches — not CAD renders. These can be done digitally in a sketch style (iPad/tablet sketch, Illustrator pencil style, etc.) as long as they look hand-drawn and annotated.
All dimensions, materials, nozzle positions, and component specifications are provided below in full detail. You do not need to do any engineering calculations — just model exactly what is specified.
Deliverables
Deliverable 1: Conceptual Design Sketches (2–3 annotated diagrams)
Sketch 1 — System Overview / Flow Path Diagram
A side-view schematic sketch showing the full system from left to right:
* Acid stream inlet and base stream inlet (from left, labelled "From WP3 Reactor")
* Arrows entering the neutralisation mixing chamber (large horizontal cylinder)
* Internal baffles shown inside the chamber (4 alternating plates with gaps)
* pH sensor shown on top of the chamber at the outlet end
* Discharge pipeline running horizontally to the right (50 m, show as a line with break marks "//")
* Valves along the pipeline: manual gate valve (HV-401), motorised ESD valve (XV-401), check valve (CV-401)
* Pipeline connecting to the multiport diffuser (long horizontal pipe with 12 angled nozzles pointing upward at 60°)
* Diffuser sitting on a seabed base frame
* Environmental monitoring cluster on a vertical mast at the far end
* Seabed shown as a hatched line beneath everything
* Label "To Ocean" above the diffuser jets
* Recirculation loop shown as a dashed line from the pipeline (after the chamber) back to the chamber inlet, with a small pump symbol (P-401A/B)
* Annotate with: flow direction arrows, component names, pipe sizes (DN300, DN350), key dimensions (chamber: 1.6m dia × 4.8m long, pipeline: 50m, diffuser: 18m long)
Sketch 2 — Mixing Chamber Cross-Section
A longitudinal cross-section through the centre of the mixing chamber showing:
* Cylindrical shell with wall thickness (12 mm) shown
* 2:1 ellipsoidal dished ends at both ends
* Four internal baffles:
* Baffles 1 & 3 attached to the top with 400 mm gap at bottom
* Baffles 2 & 4 attached to the bottom with 400 mm gap at top
* Flow path shown with arrows weaving up and down through the baffle gaps (serpentine path)
* Nozzle positions annotated:
* N1 (Acid in, DN150, 10 o'clock on inlet head)
* N2 (Base in, DN150, 2 o'clock)
* N3 (Outlet, DN300, bottom at x=4000mm)
* N4 (pH sensor, DN50, top at x=4000mm)
* N5 (Recirc return, DN100, bottom at x=200mm)
* N6 (Drain, DN50, bottom of outlet head)
* N7 (Vent, DN25, top of inlet head)
* N8 (CIP, DN50, inlet head)
* Key dimensions:
* ID = 1600 mm
* L = 4800 mm
* Baffle spacing = 960 mm
* Baffle diameter = 1200 mm
* Saddle supports shown beneath the vessel at x = 1200 mm and x = 3600 mm
Sketch 3 — Diffuser Detail
A close-up sketch of 3–4 diffuser ports on the header pipe showing:
* DN350 header pipe in cross-section/side view
* Branch nozzles angled at 60° from horizontal, showing the removable nozzle insert inside
* O-ring groove on the insert
* Retaining collar with M12 bolts
* Anti-scour mattress shown beneath the base frame
* Seabed base frame cross-member with U-cradle support
* Annotate: port spacing = 1500 mm, port ID = 65 mm, insert length = 100 mm, jet direction arrows
Style: Clean engineering sketch style — black lines on white, annotations with leader lines and dimension callouts. Must look like hand-drawn concept sketches, NOT CAD screenshots.
Format: High-resolution PNG or PDF, minimum 300 DPI, A3 landscape.
Deliverable 2: Fusion 360 CAD Model (5 components + assembly)
All components modelled as separate files, then assembled in one top-level assembly.
Component 1: Neutralisation Mixing Chamber (V-401)
Vessel shell:
* Horizontal cylinder
* Internal diameter (ID): 1600 mm
* Wall thickness: 12 mm → Outer diameter (OD): 1624 mm
* Barrel length: 4800 mm
* Both ends: 2:1 semi-ellipsoidal dished heads
* Semi-major = 812 mm
* Semi-minor = 406 mm
* Same 12 mm wall thickness
* Material appearance: Brushed stainless steel
Nozzles (8 total):
* N1 (Acid in): DN150, inlet dished end, 30° CW from 12 o'clock, 200 mm projection, flanged, reinforcing pad
* N2 (Base in): DN150, opposite side, same specs as N1
* N3 (Outlet): DN300, bottom at x = 4000 mm, 250 mm projection, flanged, reinforcing pad
* N4 (pH sensor): DN50, top at x = 4000 mm, 150 mm, threaded
* N4A (spare): DN50 at x = 4150 mm
* N5 (Recirc return): DN100, bottom at x = 200 mm, flanged
* N6 (Drain): DN50, outlet head bottom
* N7 (Vent): DN25, inlet head top
* N8 (CIP): DN50, inlet head
(Include full flange specs and reinforcing pads exactly as provided.)
Internal baffles (4):
* Ø1200 mm, 12 mm thick
* Positions: x = 960, 1920, 2880, 3840 mm
* Alternating top/bottom hung with 400 mm gaps
* Trimmed to fit vessel ID
Saddle supports (2):
* 120° contact angle
* 16 mm thick plate
* Width: 300 mm
* Baseplate: 600 × 400 × 20 mm
* Positions: x = 1200 mm and 3600 mm
* Include PTFE wear pad
Component 2: Discharge Pipeline (Line 401-C)
* DN300 pipe, 50 m total length
* Vertical drop via 90° elbow, then horizontal run
* Valves (simplified blocks): HV-401, XV-401, CV-401, HV-403
* Flanged connections throughout
* 17 pipe supports at 3 m spacing
Component 3: Multiport Diffuser Manifold
* DN350 header, 18 m long
* DN300 inlet + reducer
* DN350 blind flange at end
* 12 angled DN65 ports (60° upward)
* Reinforcing pads at each branch
* Removable nozzle insert (separate component, with O-ring grooves and retaining collar)
Component 4: Seabed Base Frame
* 20 m × 2 m structure using 200 × 200 SHS
* Cross-members at 2 m spacing
* U-cradle supports for pipe
* Levelling feet (M30 threaded)
* Pad eyes (4)
* Ballast pockets (4)
* Anti-scour mattresses beneath
Component 5: Monitoring Bracket
* 1.5 m vertical mast (DN80)
* Sensor rail with 5 instrument mounts
* Cable routing down mast
* Subsea junction box mounted to frame
Assembly Instructions
* Base frame fixed at origin
* Diffuser mounted onto frame
* Pipeline connected to diffuser
* Mixing chamber connected upstream
* Monitoring bracket mounted
* Umbilical cable routed along system
Required CAD Views / Renders
* Full isometric assembly
* Side elevation (50 m pipeline)
* Mixing chamber close-up
* Cross-section with baffles
* Diffuser port detail
* Nozzle exploded view
* Base frame detail
* Top plan view
File Delivery
* Fusion 360 files (.f3d / .f3z)
* STEP file
* Rendered PNG images
* Concept sketches (A3, 300 DPI)
Material Appearances
* Stainless steel (chamber, pipeline, diffuser)
* Galvanised steel (frame)
* Dark grey (valves, sensors)
* Concrete (mattresses)
* White (PTFE pads)
* Black (umbilical cable)
Important Notes
* CAD does NOT require manufacturing tolerances
* All dimensions in millimetres
* Do not deviate from provided specs
* Valve internals not required
* Pipe supports can be simplified
* Sketches must be hand-drawn style
* Export all views as separate files
* Ask if anything is unclear before modelling
Skills Required
* Autodesk Fusion 360 (expert)
* Mechanical / piping design experience
* Engineering sketching / technical illustration
I will also need 2–3 hand-drawn style conceptual design sketches (annotated diagrams showing the system layout, flow path, and key components) that look like engineering concept sketches — not CAD renders. These can be done digitally in a sketch style (iPad/tablet sketch, Illustrator pencil style, etc.) as long as they look hand-drawn and annotated.
All dimensions, materials, nozzle positions, and component specifications are provided below in full detail. You do not need to do any engineering calculations — just model exactly what is specified.
Deliverables
Deliverable 1: Conceptual Design Sketches (2–3 annotated diagrams)
Sketch 1 — System Overview / Flow Path Diagram
A side-view schematic sketch showing the full system from left to right:
* Acid stream inlet and base stream inlet (from left, labelled "From WP3 Reactor")
* Arrows entering the neutralisation mixing chamber (large horizontal cylinder)
* Internal baffles shown inside the chamber (4 alternating plates with gaps)
* pH sensor shown on top of the chamber at the outlet end
* Discharge pipeline running horizontally to the right (50 m, show as a line with break marks "//")
* Valves along the pipeline: manual gate valve (HV-401), motorised ESD valve (XV-401), check valve (CV-401)
* Pipeline connecting to the multiport diffuser (long horizontal pipe with 12 angled nozzles pointing upward at 60°)
* Diffuser sitting on a seabed base frame
* Environmental monitoring cluster on a vertical mast at the far end
* Seabed shown as a hatched line beneath everything
* Label "To Ocean" above the diffuser jets
* Recirculation loop shown as a dashed line from the pipeline (after the chamber) back to the chamber inlet, with a small pump symbol (P-401A/B)
* Annotate with: flow direction arrows, component names, pipe sizes (DN300, DN350), key dimensions (chamber: 1.6m dia × 4.8m long, pipeline: 50m, diffuser: 18m long)
Sketch 2 — Mixing Chamber Cross-Section
A longitudinal cross-section through the centre of the mixing chamber showing:
* Cylindrical shell with wall thickness (12 mm) shown
* 2:1 ellipsoidal dished ends at both ends
* Four internal baffles:
* Baffles 1 & 3 attached to the top with 400 mm gap at bottom
* Baffles 2 & 4 attached to the bottom with 400 mm gap at top
* Flow path shown with arrows weaving up and down through the baffle gaps (serpentine path)
* Nozzle positions annotated:
* N1 (Acid in, DN150, 10 o'clock on inlet head)
* N2 (Base in, DN150, 2 o'clock)
* N3 (Outlet, DN300, bottom at x=4000mm)
* N4 (pH sensor, DN50, top at x=4000mm)
* N5 (Recirc return, DN100, bottom at x=200mm)
* N6 (Drain, DN50, bottom of outlet head)
* N7 (Vent, DN25, top of inlet head)
* N8 (CIP, DN50, inlet head)
* Key dimensions:
* ID = 1600 mm
* L = 4800 mm
* Baffle spacing = 960 mm
* Baffle diameter = 1200 mm
* Saddle supports shown beneath the vessel at x = 1200 mm and x = 3600 mm
Sketch 3 — Diffuser Detail
A close-up sketch of 3–4 diffuser ports on the header pipe showing:
* DN350 header pipe in cross-section/side view
* Branch nozzles angled at 60° from horizontal, showing the removable nozzle insert inside
* O-ring groove on the insert
* Retaining collar with M12 bolts
* Anti-scour mattress shown beneath the base frame
* Seabed base frame cross-member with U-cradle support
* Annotate: port spacing = 1500 mm, port ID = 65 mm, insert length = 100 mm, jet direction arrows
Style: Clean engineering sketch style — black lines on white, annotations with leader lines and dimension callouts. Must look like hand-drawn concept sketches, NOT CAD screenshots.
Format: High-resolution PNG or PDF, minimum 300 DPI, A3 landscape.
Deliverable 2: Fusion 360 CAD Model (5 components + assembly)
All components modelled as separate files, then assembled in one top-level assembly.
Component 1: Neutralisation Mixing Chamber (V-401)
Vessel shell:
* Horizontal cylinder
* Internal diameter (ID): 1600 mm
* Wall thickness: 12 mm → Outer diameter (OD): 1624 mm
* Barrel length: 4800 mm
* Both ends: 2:1 semi-ellipsoidal dished heads
* Semi-major = 812 mm
* Semi-minor = 406 mm
* Same 12 mm wall thickness
* Material appearance: Brushed stainless steel
Nozzles (8 total):
* N1 (Acid in): DN150, inlet dished end, 30° CW from 12 o'clock, 200 mm projection, flanged, reinforcing pad
* N2 (Base in): DN150, opposite side, same specs as N1
* N3 (Outlet): DN300, bottom at x = 4000 mm, 250 mm projection, flanged, reinforcing pad
* N4 (pH sensor): DN50, top at x = 4000 mm, 150 mm, threaded
* N4A (spare): DN50 at x = 4150 mm
* N5 (Recirc return): DN100, bottom at x = 200 mm, flanged
* N6 (Drain): DN50, outlet head bottom
* N7 (Vent): DN25, inlet head top
* N8 (CIP): DN50, inlet head
(Include full flange specs and reinforcing pads exactly as provided.)
Internal baffles (4):
* Ø1200 mm, 12 mm thick
* Positions: x = 960, 1920, 2880, 3840 mm
* Alternating top/bottom hung with 400 mm gaps
* Trimmed to fit vessel ID
Saddle supports (2):
* 120° contact angle
* 16 mm thick plate
* Width: 300 mm
* Baseplate: 600 × 400 × 20 mm
* Positions: x = 1200 mm and 3600 mm
* Include PTFE wear pad
Component 2: Discharge Pipeline (Line 401-C)
* DN300 pipe, 50 m total length
* Vertical drop via 90° elbow, then horizontal run
* Valves (simplified blocks): HV-401, XV-401, CV-401, HV-403
* Flanged connections throughout
* 17 pipe supports at 3 m spacing
Component 3: Multiport Diffuser Manifold
* DN350 header, 18 m long
* DN300 inlet + reducer
* DN350 blind flange at end
* 12 angled DN65 ports (60° upward)
* Reinforcing pads at each branch
* Removable nozzle insert (separate component, with O-ring grooves and retaining collar)
Component 4: Seabed Base Frame
* 20 m × 2 m structure using 200 × 200 SHS
* Cross-members at 2 m spacing
* U-cradle supports for pipe
* Levelling feet (M30 threaded)
* Pad eyes (4)
* Ballast pockets (4)
* Anti-scour mattresses beneath
Component 5: Monitoring Bracket
* 1.5 m vertical mast (DN80)
* Sensor rail with 5 instrument mounts
* Cable routing down mast
* Subsea junction box mounted to frame
Assembly Instructions
* Base frame fixed at origin
* Diffuser mounted onto frame
* Pipeline connected to diffuser
* Mixing chamber connected upstream
* Monitoring bracket mounted
* Umbilical cable routed along system
Required CAD Views / Renders
* Full isometric assembly
* Side elevation (50 m pipeline)
* Mixing chamber close-up
* Cross-section with baffles
* Diffuser port detail
* Nozzle exploded view
* Base frame detail
* Top plan view
File Delivery
* Fusion 360 files (.f3d / .f3z)
* STEP file
* Rendered PNG images
* Concept sketches (A3, 300 DPI)
Material Appearances
* Stainless steel (chamber, pipeline, diffuser)
* Galvanised steel (frame)
* Dark grey (valves, sensors)
* Concrete (mattresses)
* White (PTFE pads)
* Black (umbilical cable)
Important Notes
* CAD does NOT require manufacturing tolerances
* All dimensions in millimetres
* Do not deviate from provided specs
* Valve internals not required
* Pipe supports can be simplified
* Sketches must be hand-drawn style
* Export all views as separate files
* Ask if anything is unclear before modelling
Skills Required
* Autodesk Fusion 360 (expert)
* Mechanical / piping design experience
* Engineering sketching / technical illustration