Vapor Phase Cleaning Application of DECON-X Example
Vapor Phase Application of DECON-X and DECON-X
Preparatory:
Obtain simplified process flow diagram review; with operations, the sequence and priority for equipment decontamination. Mark up diagram to show DECON-X injection points and vent locations; show flow path for vapor cleaning through process vessels.
Prepare a layout page showing sequence and volumes of DECON-X (or DECON-X). Time, temperature, results, and rinse columns will be completed as application proceeds.
Application:
Prior to pumping DECON-X, verify the following, by physically checking:
1) Vessel is drained - Condensate not hydrocarbon coming from bottom drain connection. Do not rely on control instrument levels. They may be plugged or blocked in.
2) Vessel is vented to relief system, sometimes called blowdown or vapor recovery system.
3) DECON-X injection valves into vessel are open, and that only one flow path for DECON-X exists.
4) Check and record vessel temperature. Depending on system flow and vessel size, temperature should be over 200°F after a couple of hours of steaming.
5) Check rinse line (reflux line) to be free of H.C. and hot via steam.
Begin pumping DECON-X into vessel:
Typically one drum per 20 minutes. After pumping ½ of the calculated DECON-X required, re-check drain line, any top vent connection and reflux (rinse) line for DECON-X lemon odor to verify vaporization is adequate. When completed, DECON-X injection continue steaming for several more hours; then have operations lower steam rates dropping vessel pressure and perform sniff for LEL, benzene, and H2S. If vessel is a column, the overhead accumulator would have DECON-X injected immediately after column DECON-X injection and would be sniffed at the same time as column.
If sniff OK, start fresh water rinse, hot water is preferred. Maximize flow of rinse & continue for several hours until the bottom drain is clear of soap emulsion. Caution, do not use accumulator water or reflux pump as water rinse source. The accumulator may have sludge emulsion from DECON-X cleaning and could recontaminate column.
After:
Complete layout page info and discuss with operations. Flush DECON-X pumps with water. Remove empty DECON-X drums to location for later pick up.