| 摘要 |
<p>A water boiler has a series of upright heat exchanger tubes that accumulate combustion deposits removed by insertion of a high pressure hanging water lance. Following insertion the lance rotates back and forth about a zero position in which the water jet is directed downwards, in which position it is in-line with a water trap vessel (9) inlet. The vessel has sidewall outlets and may be raised or lowered as required.</p> |
