| 摘要 |
<p>An air temperature control apparatus for controlling the temperature of drying air for kilning comprising two heat exchange units W1 and W2 each having two elements W11, W12 and W21 and W22 respectively. One of the units W1 is placed in thermal contact with hot exhaust air FL, the other W2 in contact with cold feed air AL. The units W1, W2 are connected via heat conducting fluid lines such that by altering the position of valves 21 heat can be transferred either directly from unit W1 to unit W2, or indirectly via a heat pump circuit 16 comprising an evaporator unit 17, a compressor 18, a condenser unit 19 and a pressure reducer 20 such that heat is transferred at a higher temperature, or both. A waste heat exchange circuit 37 is connected to a motor 27 which drives the pressure reducer 20 to allow waste heat to be extracted and transferred via piping to a waste heat exchange element 26 which serves to further heat the feed air AL. <IMAGE></p> |
