摘要 |
The process heats a flowing medium using a heat-exchange pipe, one of whose ends is higher than the other. An upwards current of the medium is generated, in contact with the outside of the pipe, while the hot products of the combustion of gaseous fuel and air are forced downwards through the pipe. Flow speeds and temps. are such that the combustion products are cooled below thier dew point before leaving the pipe. The process can be used to heat water, the combustion products being forced through the pipe by a fan. A shutter at the pipe outlet opens only when the fan is running. |