HEAT EXCHANGER

摘要

The heat-exchanger is self-cleaning during operation without any external cleaning methods. It includes a spiral insert (9) fixed in a housing (2). There is a spiral groove (20) for one heat-exchange operating medium between the windings of insert (9). Insert (9) is designed with a groove (10) for the second heat-exchanging operating medium. A central tube (13) which is axially mobile and has revolving facility has scraping elements for removing the accretion in groove (20). In one alternative the scraping element is in the form of a spiral insert (15) having the same design as insert (9). Insert (15) has a groove (16) for the second heat-exchanging medium. In another alternative central tube (13) has one or more scraping arms which can be cooled by a coolant. When accretion is formed on the heat-exchange surfaces, the cleaning cycle is effected by axial shifting of insert (15) which is assembled on the central tube (13) to the fixed mounted insert (9) where the heat-exchanging surfaces get in touch next to each other. Then a rotative motion is performed, e.g. part of a revolution, when the surfaces are close to each other or are in contact one next to the other, and in this way the accretion on both surfaces are rubbed or scraped out and the groove is being cleaned. 7 claims, 2 figures