Ilya -
250kg week is 2500, 100gr bars or about 3500 70gr bars. If your mold has 3 cavities in it and you can process 3 molds per minute thats 3x3x60 or 540 bars/hour. So, molding 250kg would take 5-7 hours per week at those speeds. Tempered chocolate requirement is ~35-50kg/hr.
Cooling time is dependent on several things, with the thickness of the bar a key factor. A 7mm-thick bar is going to take a lot longer than a 3mm-thick bar (the time difference might not be a linear function).
If it takes 15 minutes to cool down a mold (a cooling tunnel will make this much faster, BTW), then you need to have a minimum of 45 molds at 3 molds/minute if everything went perfectly and there were no delays. To be safe you will want twice that number.
Throughput is going to be dependent on getting your molds into the mold loader, de-molding at the other end, and returning the mold to the mold loader.
One of the things people think is that going to a cooling tunnel eliminates labor. That's not strictly the case as you need people to operate the machine. A skilled operator and manual dosing can do a lot more than you think. It's about organizing production to be efficient.
A case in point is to consider that at .5 meters/minute you need at least a 7.5 meter cooling tunnel to keep up. And that's going to mean a lot of walking from one end of the tunnel to the other.
[ That's not the case with the Selmi bar tunnels because there is one fold. They go down to one end then move to another level, and return to the beginning. ]
A specialized crystallization fridge with 20 racks can probably hold 80-90 molds. It might cost you $6-7000 delivered. By the time you put the bottom tray into the fridge the bars on the top rack will be ready to take out. The operator can work at their own pace - it's not dictated by the machine.
When you need to double production, duplicate the line. It will be less expensive and require less space. When your production projections reach into the 1000 bar/hour range and you have to run at that pace for more than 5 hours/day, then go get a tunnel. And then consider a folded (vertical) tunnel not a linear tunnel.
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@DiscoverChoc