Desalination plant with PAHAP cleaning unit

摘要

1. A sea-water desalination plant, with a plurality of tubular heat exchanger stages each with a tubular heat exchanger and a tube cleaning appliance, in which cooling water flows through the tubes of the tubular heat exchanger stages, and the tubular heat exchanger stages are series connected by a cooling water pipe system in respect of the flow of cooling water, in which moreover the tube cleaning appliance, that operates with cleaning bodies, possesses a cleaning bodies infeed in the cooling water supply before the heat exchanger plant and a cleaning bodies offtake with offtake sieve in the cooling water outlet from the heat exchanger plant, in which also the cleaning bodies offtake and the cleaning bodies infeed are connected together by a cleaning pipe system with a cleaning bodies lock and pump, which cleaning bodies lock possesses a collecting sieve for the cleaning bodies with a lock chamber situated before the collecting sieve and a lock chamber situated after the collecting sieve, and which cleaning pipe system possesses on one hand a hot water pipe leading from the cleaning bodies offtake to the lock chamber situated before the collection sieve and a hot water return pipe attached to the lock chamber situated after the collecting sieve, and on the other hand a cold water pipe leading from the area of the cleaning bodies infeed to the cleaning bodies lock and a cold water plus cleaning bodies return pipe leading back from the lock chamber situated before the collecting sieve to the cleaning bodies infeed, and in which the tube cleaning appliance can be changed over from cleaning to collecting by change-over valves that form part of the cleaning pipe system, characterized in that pump (13) of the tube cleaning appliance (2) is located in a short feed pipe (34) of the cleaning bodies lock (12) which opens out into the lock chamber (15) situated before the collecting sieve (14), that both the hot water pipe (17) and the cold water pipe (19) are attached to the short feed pipe (34) before pump (13), and accordingly can be changed over from admission of hot water to admission of cold water, and thereby from collecting to cleaning, by valves (21, 23, 24, 25, 26, 28, 30, 31, 32, 33), and that finally the tube cleaning appliance possesses at least two additional cleaning pipes (35, 36) with valves (22, 27, 29, 30, 31, 32, 33) for opening and closing them, one of which (35) leads off from the cooling water pipe system (4) and is also attached to the short feed pipe (34) before pump (13) and the other of which (36) feeds back into the cooling water pipe system (4) before the tubular heat exchanger stage (1) or stages to be cleaned.