Abstract: A boom system having a flexible barrier is supported by floats on offset arms. The offset arms and floats thereon are mounted to the barrier in a manner which allows the angle between the barrier and the offset arms to be easily varied. The orientation of the barrier with respect to the surface the boom system is disposed on can thus be easily varied to account for variations in wind, waves and currents. Furthermore, the orientation of the barrier is controlled without the use of ballast weights.

Abstract: Recirculating tube cleaners pass through inside diameters in a bank of heat exchanger tubes. Variable density tube cleaners are provided which are pressurized to compress and have a substantially neutral buoyancy upon entry from an inlet manifold to the inside diameter of the tubes. Upon exiting from a heat exchanger outlet manifold, the tube cleaners return to either positive or negative buoyancy depending upon the embodiment. Skimmer means intercept tube cleaners having positive buoyancy from the upper portion of flow and direct them to a recirculation system. Open cell elastomer tube cleaners having negative buoyancy may be intercepted at the bottom of the flow and then partially dewatered for adjustment toward neutral buoyancy. As contrasted to prior art embodiments in which the entire outlet flow must be screened, here only a small percentage, for example one percent of the outlet flow, need be intercepted.

Abstract: A cleaning device for heat exchanger tubes comprising a rubbing body consisting of a hollow casing member of elastomeric material with diametrical openings, and an encased check ball. A thickened band extends intermediately around the casing member for rubbing against the tube wall and is provided with slots enhancing the flexibility of the band. The overall density of the device approximates that of the liquid with which it is to be used.