Chocolate Cooling Tunnel

ETCTA, ETCTI, CTA, or CTI — which model?

Four sequential decisions narrow the choice:

• Conveyor type follows product format: PU belt for enrobed products and belt-deposited drops/coins/callets; rod or modular belt for cooling molded chocolate.
• Chassis follows the constrained axis (molded production): horizontal CTA/CTI is longest but uses standard ceiling height; ETCTA/ETCTI elevator saves up to 80% length but needs a tall ceiling; multi-storey sits between the two on both.
• Combined molded + enrobed: only multi-storey does both in one chassis — capped at 50 kg/h enrobing throughput.
• Elevator family by mold footprint: ETCTA for 175×275 mm molds (108 / 144 / 180) on artisan lines; ETCTI for 205×600 mm molds at higher capacity on industrial lines.
• PU belt family by length: CTA covers 4–12 m (belt 300–800 mm); CTI covers 12–30 m (belt 600–2000 mm). In the 600–800 mm belt overlap, production scale decides — artisan uses CTA, industrial uses CTI.

Conveyor type — PU belt, rod, or modular belt?

Product format decides:

• Polyurethane belt: enrobed products and belt-deposited drops, coins, callets — pieces release cleanly without sticking.
• Rod conveyor or modular belt: required for molded chocolate — molds need direct cold airflow underneath each cavity, which a continuous PU belt cannot provide.

CTA and CTI ship with PU belt by default but can be configured at order with rod or modular belt for mold cooling. ETCTA and ETCTI are mold-only by design. Conveyor type is fixed at order against the product format and is not field-changeable once the chassis is built.

Chassis type for molded production — horizontal, elevator, or multi-storey?

All three deliver equivalent residence time; floor area, ceiling height, and capacity decide:

• Horizontal (CTA/CTI with rod or modular belt): longest layout, standard ceiling height — when ceiling clearance is restricted but floor length is available.
• Elevator (ETCTA 18 stages, ETCTI 29 stages): saves up to 80% length but needs a tall ceiling — when floor length is restricted but overhead clearance is available. ETCTA for 175×275 mm molds, ETCTI for 205×600 mm.
• Multi-storey: between the two on both axes, artisan-scale only — when floor length and ceiling height are both partly constrained but neither is at its limit. Built on the MML100 cooling-loop principle; no own product code yet.

Picking elevator without verifying overhead clearance produces an installation that does not fit; picking horizontal without floor length wastes plant area; picking multi-storey for industrial-scale production hits the capacity ceiling.

Combined molded + enrobed in one chassis — when does multi-storey work?

Multi-storey is the only chassis where a PU belt section can run alongside the mold-cooling section, so one machine handles both. The horizontal CTA/CTI ships with one conveyor type fixed at order; ETCTA and ETCTI are mold-only.

• Fits: artisan and small-production operations running both molded and enrobed batches that want a single cooling installation.
• Does not fit: enrobing throughput above 50 kg/h — the multi-storey enrobing belt caps there, and a separate CTA or CTI with PU belt is required instead.

ETCTA or ETCTI — when does the artisan elevator run out?

Mold footprint decides. ETCTA covers 175×275 mm molds at capacities 108 / 144 / 180 — sized for artisan and small molding lines that run molds in the 175×275 mm format. 18 vertical stages, total power 8.5 kW. ETCTI covers 205×600 mm molds at higher capacities — sized for industrial molding lines that run wider, longer molds; 29 vertical stages, capacity and power scale with chassis size (typical 10.5 kW) and are confirmed at order. Picking ETCTA on an industrial molding line with 205×600 mm molds fails — the artisan chassis cavity does not accept the larger mold footprint; picking ETCTI on an artisan line with 175×275 mm molds wastes elevator volume and the larger refrigeration load. The two share construction (AISI 304, CFC-free insulation, evaporator and condenser, rodless pneumatic transfer at the top) — what differs is stage count, mold-handling cavity, and refrigeration sizing.

CTA or CTI — when does the artisan model run out?

Length is the hard switch; belt width covers a partly overlapping envelope. CTA covers tunnels 4–12 m with belt widths 300–800 mm — sized for workshop and small-production enrobing lines, drops/coins/callets at modest throughput. CTI covers tunnels 12–30 m with belt widths 600–2000 mm — sized for industrial enrobing lines, wide-belt drop production, and high-capacity callet output. Belt widths 600–800 mm fall in both families: production scale decides — artisan or small-production scale uses CTA, industrial scale uses CTI. Picking CTA for a tunnel longer than 12 m fails — single-pass residence time cannot be reached at the artisan refrigeration sizing; picking CTI for a 4–12 m artisan setup wastes belt area and the larger refrigeration load. The two share cabinet construction and refrigeration components — what differs is belt and length envelope plus refrigeration sizing.

How is residence time sized?

Residence time is the dwell inside the cooling tunnel from infeed to discharge — the time available for the chocolate to set. Sizing depends on product mass per piece, deposit or mold cavity depth, infeed temperature, and the cooling-zone air temperature profile. Drops and chips solidify quickly because each piece is small; molded pieces need longer because the core cools by conduction through the mold wall; thick enrobed centers need longer still because solidification depth grows as the square root of time. Undersized residence time discharges soft pieces — they deform on collection or stick to the next piece on the belt, or release poorly from the mold. The tunnel is sized at the order against the longest-cycle product the line will run; recipe recall on the line PLC handles changeover within that envelope.