Multiple Coolers | CAL3K Features

The cooler is the slowest system component. We have optimised it as best we can; but it is slow! It cools a vessel down by blowing air at it. Not a very efficient way, BUT very resource friendly and economical. Cooling the vessel with air is possible because the temperature RANGE of the vessel is large: 1°C to 70°C. It is limited on the top by the operator feeling the warm bomb. Above 55°C the CAL3K outputs a warning that the vessel is warm to the touch.​

A 'standard' charge increases the vessel temperature by ~12.5°C. To cool this down to an ambient temperature takes an infinite time. However, cooling it down to Ambient +8°C requires ~7 minutes.This means that the cooler performs better if it works well above the ambient temperature. The 8°C is the Ambient Cooling Gap.​

Assuming a ambient temperature of 25°C and a firing temperature of 33°C (Cooling Gap=8°C) then the cooler needs 7 minutes to cool the warm vessel (33+12.5°C=45.5°C) down to 33°C.​

If the 7 minute cooling is insufficient (too slow) then two options exist :​

  • A) Use two coolers. This requires 3 bombs!
  • B) Increase the cooling performance by increasing the Cooling Gap. This can be done two ways:
    • B1) Air conditioning the room to 22°C. This rises the cooling gap to 11°C.
    • B2) Raise the cooling target to 36°C. Then a warm vessel is about 49°C (acceptable), and the cooling gap is 11°C.
    • B3) Use air conditioning and raise to cooling gap : You can get cooling cycles of less than 5 minutes.
  • The cooler can be programmed to a fixed target or to flexible target which consists of the ambient plus the Cooling Gap. The latter method results in foxed cooling times.

This is all very technical. Our recommendation (if the above doesn't suit your application) : Purchase an extra air cooler.

This feature applies to the following CAL3K Systems : CAL3K-AP , CAL3K-A , CAL3K-U, CAL3K-F


Multiple CAL3K Air Coolers | DDS Calorimeters

AIR COOLER

The cooler 3K-2 can be controlled from the CAL3K or via the USB port at the rear. The cooler indicates this on its display: COOLING FROM VESSEL. Another way to change the cooling parameters is to connect the cooler to a PC via the USB interface and change the parameters.

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IMPROVED AIR COOLER

The new Air Cooler replaces the traditional (but very fast and expensive) water cooler. It also uses less resources (electricity & water). The air cooler works best when the vessel temperature is well above the ambient temperature. This is possible because the CAL3K vessel, with linear temperature sensing, allows higher vessel temperatures. The air cooler can cool a vessel in 6-7 minutes from 44°C to 32°C when the ambient (room) temperature is at 25C.

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SYSTEM CONFIGURATION

The system timing depends on the timing of the CAL3K and the Air Cooler. The cooling cycle depends on the room temperature: A warmer room temperature results in longer cooling times. The Cooler ‘READY’ time can be adjusted to suit your operating conditions, but an average of 7 minutes per cooling cycle is the design target.

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