Feasibility of Mechanical Cleaning 



Housing . A system using a combination of multibrush vehicles and hand-held 

 single rotary brushes could remove fouling on all exterior surfaces on 

 either OTEC plant concept. This includes the central platform of the 

 Lockheed concept if it proves to be weight critical in actual service and 

 the exterior of the four power modules, if the surface becomes heavily 

 fouled between dry-docking schedules. To permit driver access to the warm 

 water inlet, the vertical screen of the TRW concept should be attached to 

 the main platform in sections. Each section should be hinged at the upper 

 end and equipped with butterfly lug connections at the lower end. A stop 

 should be provided at the hinges so that the inner surface remains firm 

 when it is being cleaned. The Lockheed warm water inlet screen also could 

 be attached in sections with hinges at the inner circumference and with 

 butterfly lug connections at the outer circumference. However, because 

 of its horizontal design, the entire screen could be raised in one piece. 

 In this case, the screen would float freely and could be positioned by its 

 own negative buoyancy. A stop or projection should be provided to limit 

 the ascent of the screen when it is in the floating mode along the center 

 core. The warm water inlet is cleaned in the following manner: 



1. The diver cleans the exterior surface of the screen with SCAMP. 

 This is expected to be more efficient than Brush-Kart on screened surfaces. 



2. The divers then attach deflated flotation collars around the 

 outer and inner circumference. 



3. The collars are inflated with compressed air to provide suffi- 

 cient buoyancy to raise the screen vertically using the core section as 

 a guide. 



4. The divers clean the interior surface of the ducts leading to the 

 evaporator with a multibrush vehicle. 



The SCAMP impeller should be equipped with a flexible manifold which 



transfers water containing debris to a containment area similar to a scheme 



1 30 

 patented in Japan. The debris may require containment to prevent its 



ingress into the heat exchanger during restart. It may be necessary to 



use a hydraulic jet unit to clean the less accessible areas of the duct. 



The inside of the warm water inlet should have recessed hand and foot rails. 



63 



