Wood preservation facilites, pentachlorophenol thermal: chapter F, table 13

Table of contents

Next page

Table 13. Additional Recommended Design Features for PCPT Treatment Process Systems

(Use in conjunction with Part I, Chapter A - General Recommendations for All Wood Preservatives, Table 13.)

Objectives:

To minimize and contain all releases of PCP
To recover and recycle releases that occur
To provide fail-safe operation of the treatment system
To minimize the potential for PCP spills
To conform with the NFCC

Design feature	Recommendations
Shelter, configuration	Use exterior treatment tank. Locate other process equipment and systems in a centralized area. Provide heated (where necessary) enclosure for process controls, with any air emissions vented externally.
Tanks, piping and valves	Provide effective access and containment for all subsurface tanks and piping.
Process emissions to air	Locate treatment tanks so as to minimize downwind effects either to yard workers or to adjacent properties actively used for residential/commercial purposes. Install any control equipment as necessary to comply with applicable emission limits. Provide vapour traps for hot liquid tank vents and vacuum exhaust. Vent tank vapours (cold storage) to outside.
Treating tanks	Engineer treatment tanks for long-term integrity. Ensure that tanks are secured to prevent uplifting. Provide secondary containment vessel or other impermeable containment around treatment tanks. Install an effective protection device to prevent overfilling of treatment tanks with preservative: Install independent overflow indication/alarm/pump interlocks between the treating tanks and the control point (where the tank is not visible from the control point). Provide containment for collection and direct return of tank overflow. Construct overflow connection as per the NFCC. Provide corrosion protection of subsurface steel tanks as per the NFCC. Provide for tank lids or roofing to reduce vapour emissions and to reduce or prevent rain and snow falling into tanks. Construct lids as per the NFCC. Provide walkway grates (or alternative design) to prevent worker contact or tracking of chemicals. Provide guard rails and other safety measures as required by provincial authorities for operations near open tanks. Provide means to contain frothing and/or overflows.
Piping and recycle systems	Design an overall system that is effective at containing and recycling all chemicals, with minimum potential for release and dispersal and minimum infiltration of water. Select and install piping as per Table 11 of Chapter A.
Process controls	Design for simple, unambiguous operation (regardless of the degree of automation). Establish a clear relationship between process controls and process functions in order to minimize operator error (e.g. provide flow diagrams for process).

Table of contents

Next page

Page details

Date modified:: 2014-07-08