managers. The amount of acid to be added varies depending on the size and type of
the unit. Consult the manufacturer's instructions. Generally, the acid cleaning is
continued during a 2-hour recirculation period; methyl orange is used as the indicator
to show when the acid is spent. After treatment, drain the unit, flush well, rinse with
alkaline solution to neutralize any remaining acid, and return to service.
The equipment needed to remove scale formation
mechanically includes an electric drill with bit and wire brush attachments that fit the
through the drill bit during operation. Drill each tube and then wire brush. Remove
scale from the evaporator shell or head by scraping; remove all dislodged particles of
scale from the evaporator. Reassemble the evaporator and return it to service.
Note: For safety, ground the electric drill used for removing scale, and
protect the operator from electrical shock resulting from using an electric drill in a wet
Check all mechanical controls, fuel lines, electrical connections,
lubrication points, and valves each quarter.
exchanger, cooler system, and instrumentation twice a year. Clean, adjust, and repair
this equipment as necessary.
Check the entire system. Clean, repair each year, and paint as
Maintenance Procedure Schedule. Maintenance operation frequencies
and the schedule of inspection for distillation equipment are summarized in Table 38.
Electrodialysis Equipment. When establishing maintenance procedures,
follow the detailed instructions provided by the equipment manufacturer. General
maintenance procedures for electrodialysis equipment can be found in par. 2.2.27.
Reverse Osmosis Equipment. Membrane equipment is very specialized.
Maintain it in accordance with the manufacturer's instructions. General information on
reverse osmosis equipment maintenance--including daily, weekly and monthly
monitoring, membrane cleaning, and troubleshooting procedures for a variety of
operating problems--can be found in pars. 2.2.28 and 2.3.15.
Backflow Preventers. See par. 10.7.