| 摘要 |
<p>Recirculating tube cleaners pass through the internal diameter of the tubes of a bundle of heat-exchanger tubes. Use is made of tube cleaners of variable density which are subjected to a pressure in order to compress them and which have a neutral ascending force when they enter the internal diameter of the tubes from an inlet manifold (collector). On their exit from the outlet manifold of the heat exchanger, the tube cleaners recover their positive or negative ascending force in accordance with the embodiment. A collecting device intercepts the tube cleaners which have a positive ascending force on the upper part of the circulation (route) and direct them towards a recirculation system. The tube cleaners made from open-cell elastomer which has a negative ascending force may be intercepted in the lower part of the circulation and are then partially dehydrated so that they have a tendency to exhibit a neutral ascending force. Unlike what occurs in prior-art embodiments in which the entire outlet circulation has to be classified, in this case it is necessary only to intercept a small percentage, for example 1% of the outlet circulation. The tube cleaners are once again entrained in a pumped stream and are reintroduced in order to circulate via the tube bundle under pressure. The tube cleaners are produced so as to have a density such that their ascending force is almost neutral so that they are distributed uniformly through the upper and lower tubes. A tube cleaner may be formed from two components, one component and an ascending-force component. It is possible to restrict the variation in density in response to pressure.</p> |
