Wood-mizer KD150 Series - Appendix; Terminology; Relay Activation Conditions

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DRY BULB: The temperature as measured by a
thermometer.
WET BULB: The temperature of a thermometer with a
wet wick over the sensor.
WET BULB DEPRESSION: The dierence between the
dry bulb temperature and the wet bulb temperature.
Example: if the dry bulb is 105º F. and the wet bulb is
98º F., the depression is 105º F. - 98º F., or 7º F.
RH-RELATIVE HUMIDITY: The ratio of the amount of
water in the air to what the air could hold. At 50%
RH, the air has 50% as much water in it as it would
hold at 100% RH. 100% is a 0º F. depression.
EMC-EQUILIBRIUM MOISTURE CONTENT: This is
the average moisture content all wood will reach
eventually when exposed to these conditions.
Example: At a dry bulb of 115º F. and a wet bulb
of 101º F., a 14º F. depression, the EMC is 10%. This
means that eventually all wood will average 10%.
Wood drier than 10% will pick up water and wood
that is wetter than 10% will give up water.
DRI-DRYING RATE INDEX: This is an index of relative
drying rate.
Example: If a dryer is operating at 120º F. and a wet
bulb depression of 12º F., and drying the load at a
rate of 1.5% per day, at the DRI is 1.1. If the wood
will dry at 2 times the rate (2.2/1.1=2), or 3% per day.
This assumes that other conditions remain the same
(airow, stacking etc.).
Appendix
Terminology
DBT Dry Bulb Temperature
WBT
Wet bulb Temperature: the difference between the dry and wet bulb
temperatures is equal to the relative moisture of the air within the
kiln.
DBT-SP Dry Bulb Temperature Set Point
WBT-SP Wet Bulb Temperature Set Point
C-SP Compressor Temperature Set Point
T-Hyst The value assigned to the temperature hysteresis parameter
H-Hyst The value assigned to the humidification hysteresis parameter
O-Thr The value assigned to the overheating threshold parameter
C-Hyst The value assigned to the compressor hysteresis parameter
Relay ON OFF
Heater DBT < DBT-SP ‒T-Hyst DBT ≥ DBT-SP
Sprayers WBT < WBT-SP ‒ H-Hyst WBT ≥ WBT-SP
Vent DBT > DBT-SP + O-Thr DBT ≤ DBT-SP
Compressor (when
enabled)
WBT > WBT-SP + C-Hyst WBT ≤ WBT-SP
Compressor enabling DBT ≥ C-SP DBT < C-SP ‒ C-Hyst
Relay Activation Conditions
Relays are subject to final moisture value and alarm conditions.
Wood-Mizer
KD150 12/22/17