Distillation — continuous ethanol/water column

{
  "nodes": [
    { "id": "cond", "type": "snowflake", "label": "Total condenser (cooling water)", "x": 390, "y": 40, "width": 150, "height": 104, "fill": "#e0f2fe", "stroke": "#0369a1" },
    { "id": "drum", "type": "cylinder", "label": "Reflux drum", "x": 565, "y": 40, "width": 150, "height": 104, "fill": "#e0f2fe", "stroke": "#0369a1" },
    { "id": "dist", "type": "bottle", "label": "Distillate — 89 mol% ethanol", "x": 740, "y": 40, "width": 150, "height": 104, "fill": "#dcfce7", "stroke": "#15803d", "bold": true },
    { "id": "vapour", "type": "wave", "label": "Vapour rises, richer in ethanol", "x": 215, "y": 200, "width": 150, "height": 104, "fill": "#f1f5f9", "stroke": "#475569" },
    { "id": "rect", "type": "stacked-cylinder", "label": "Rectifying section — trays 1 to 10", "x": 390, "y": 200, "width": 150, "height": 104, "fill": "#fef3c7", "stroke": "#a16207" },
    { "id": "reflux", "type": "gauge-chart", "label": "Reflux ratio R = L/D ≈ 3", "x": 565, "y": 200, "width": 150, "height": 104, "fill": "#e0f2fe", "stroke": "#0369a1" },
    { "id": "azeo", "type": "cross", "label": "Azeotrope — 95.6 wt%, 78.2 °C", "x": 740, "y": 200, "width": 150, "height": 104, "fill": "#fee2e2", "stroke": "#b91c1c", "bold": true },
    { "id": "sieve", "type": "honeycomb", "label": "Molecular sieve → 99.5% grade", "x": 915, "y": 200, "width": 150, "height": 104, "fill": "#f1f5f9", "stroke": "#475569" },
    { "id": "feed", "type": "flask", "label": "Feed — 10 mol% ethanol in water", "x": 40, "y": 360, "width": 150, "height": 104, "fill": "#dbeafe", "stroke": "#1d4ed8", "bold": true },
    { "id": "pre", "type": "gas-flame", "label": "Feed preheater", "x": 215, "y": 360, "width": 150, "height": 104, "fill": "#ede9fe", "stroke": "#6d28d9" },
    { "id": "ftray", "type": "layers", "label": "Feed tray — sets the q-line", "x": 390, "y": 360, "width": 150, "height": 104, "fill": "#fef3c7", "stroke": "#a16207", "bold": true },
    { "id": "liquid", "type": "water-drop", "label": "Liquid falls, richer in water", "x": 565, "y": 360, "width": 150, "height": 104, "fill": "#f1f5f9", "stroke": "#475569" },
    { "id": "pump", "type": "motor", "label": "Feed pump", "x": 40, "y": 520, "width": 150, "height": 104, "fill": "#ede9fe", "stroke": "#6d28d9" },
    { "id": "strip", "type": "stacked-cylinder", "label": "Stripping section — trays 11 to 20", "x": 390, "y": 520, "width": 150, "height": 104, "fill": "#fef3c7", "stroke": "#a16207" },
    { "id": "reb", "type": "gas-flame", "label": "Reboiler — low-pressure steam", "x": 390, "y": 680, "width": 150, "height": 104, "fill": "#ede9fe", "stroke": "#6d28d9", "bold": true },
    { "id": "bottoms", "type": "water-drop", "label": "Bottoms — water at about 100 °C", "x": 565, "y": 680, "width": 150, "height": 104, "fill": "#dcfce7", "stroke": "#15803d" }
  ],
  "edges": [
    { "id": "e1", "source": "feed", "target": "pump" },
    { "id": "e2", "source": "pump", "target": "pre" },
    { "id": "e3", "source": "pre", "target": "ftray", "label": "at its bubble point", "thickness": 2.5 },
    { "id": "e4", "source": "ftray", "target": "rect", "label": "vapour up", "thickness": 2.5 },
    { "id": "e5", "source": "ftray", "target": "strip", "label": "liquid down", "thickness": 2.5 },
    { "id": "e6", "source": "rect", "target": "vapour", "style": "dashed" },
    { "id": "e7", "source": "strip", "target": "liquid", "style": "dashed" },
    { "id": "e8", "source": "rect", "target": "cond", "label": "overhead vapour", "thickness": 2.5 },
    { "id": "e9", "source": "cond", "target": "drum" },
    { "id": "e10", "source": "drum", "target": "dist", "label": "product draw", "thickness": 2.5 },
    { "id": "e11", "source": "drum", "target": "reflux", "label": "split L and D" },
    { "id": "e12", "source": "reflux", "target": "rect", "label": "reflux returns", "thickness": 2.5 },
    { "id": "e13", "source": "dist", "target": "azeo", "label": "cannot be passed", "style": "dashed" },
    { "id": "e14", "source": "azeo", "target": "sieve", "label": "dehydrate instead" },
    { "id": "e15", "source": "strip", "target": "reb", "label": "liquid to the reboiler", "thickness": 2.5 },
    { "id": "e16", "source": "reb", "target": "bottoms", "label": "water out", "thickness": 2.5 }
  ]
}