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e. The transfer basket containing the items to be cleaned was lowered into the immersion sump , and statically (i.e. no liquid flow) sonicated for a finite pe-riod of time, usually 15 minutes. f. After static sonication, the rinse pump was turned on and the liquid in the immersion bath was circulated through the activated carbon columns at a rate of1,700 ml/minute for a finite period of time. The circulation time ranged fro m 15 minutes to 2 hours, depending on the purpose of the test. g. The rate of decontamination was monitored by following the concentration of the contaminant in the decontamination liquid (HFE-7100). h . Steps e and f were repeated until the presence of contaminant in the circulat-ing liquid could no longer be detected. i. When the immersion sump liquid was free of contaminant, the transfer basket was moved from the immersion sump to the superheat sump and dried for 30 minutes to remove liquid drag out. j . The transfer basket was removed from the Poly-Kleen™ system. The test pieces were removed from the basket, visually examined, photographed under visible and UV light, reweighed, and archived. I n order to maximize ultrasonic power density, the minimum amount of liquid needed to cover the parts being cleaned was used. Typically, the sump contained from 130 to 180 mm (5 to 7 inches) of liquid, which corresponds to a liquid vol-ume of approximately 15 liters to 30 liters (4 to 8 gallons) and a corresponding ul-trasonic power density of 26 to 18 watts/liter (100 to 70 watts/gallon). In prelimi-nary tests, it was noted that immersing and sonicating the test samples when the immersion sump was filled to the brim (about 53 liters (14 gallons)) did not result in effective cleaning. At that volume, the ultrasonic power density had dropped to a value of 8 watts/liter (30 watts/gallon). While this value would be considered marginal in a stainless steel ultrasonic bath, where the ultrasonic waves can be re-flected from the walls back into the liquid, in a polypropylene bath in which the walls absorb rather than reflect the ultrasonic waves, this power density level is too low. If parts were also contaminated with biological agents, after Step h, they would be sonicated in a fluorinated surfactant/HFE-7100 solution that would be circu-lated through microfilters to remove suspended materials. The parts would then be rinsed in fresh HFE-7100 to remove fluorocarbon surfactant residues, and then dried as described above. Table 3 lists the sensitive equipment decontamination experiments that were carried out in the Poly-Kleen™ system during the course of the program. The combination of equipment processed, contaminants used, and monitoring method(s) examined are listed in this table. The results of the various cleaning re-sults are summarized in Table 4. This table records the weights of the items listed in Table 3, before and after contamination, as well as the post-cleáning weight and visual appearance of these items.
DOI link for e. The transfer basket containing the items to be cleaned was lowered into the immersion sump , and statically (i.e. no liquid flow) sonicated for a finite pe-riod of time, usually 15 minutes. f. After static sonication, the rinse pump was turned on and the liquid in the immersion bath was circulated through the activated carbon columns at a rate of1,700 ml/minute for a finite period of time. The circulation time ranged fro m 15 minutes to 2 hours, depending on the purpose of the test. g. The rate of decontamination was monitored by following the concentration of the contaminant in the decontamination liquid (HFE-7100). h . Steps e and f were repeated until the presence of contaminant in the circulat-ing liquid could no longer be detected. i. When the immersion sump liquid was free of contaminant, the transfer basket was moved from the immersion sump to the superheat sump and dried for 30 minutes to remove liquid drag out. j . The transfer basket was removed from the Poly-Kleen™ system. The test pieces were removed from the basket, visually examined, photographed under visible and UV light, reweighed, and archived. I n order to maximize ultrasonic power density, the minimum amount of liquid needed to cover the parts being cleaned was used. Typically, the sump contained from 130 to 180 mm (5 to 7 inches) of liquid, which corresponds to a liquid vol-ume of approximately 15 liters to 30 liters (4 to 8 gallons) and a corresponding ul-trasonic power density of 26 to 18 watts/liter (100 to 70 watts/gallon). In prelimi-nary tests, it was noted that immersing and sonicating the test samples when the immersion sump was filled to the brim (about 53 liters (14 gallons)) did not result in effective cleaning. At that volume, the ultrasonic power density had dropped to a value of 8 watts/liter (30 watts/gallon). While this value would be considered marginal in a stainless steel ultrasonic bath, where the ultrasonic waves can be re-flected from the walls back into the liquid, in a polypropylene bath in which the walls absorb rather than reflect the ultrasonic waves, this power density level is too low. If parts were also contaminated with biological agents, after Step h, they would be sonicated in a fluorinated surfactant/HFE-7100 solution that would be circu-lated through microfilters to remove suspended materials. The parts would then be rinsed in fresh HFE-7100 to remove fluorocarbon surfactant residues, and then dried as described above. Table 3 lists the sensitive equipment decontamination experiments that were carried out in the Poly-Kleen™ system during the course of the program. The combination of equipment processed, contaminants used, and monitoring method(s) examined are listed in this table. The results of the various cleaning re-sults are summarized in Table 4. This table records the weights of the items listed in Table 3, before and after contamination, as well as the post-cleáning weight and visual appearance of these items.
e. The transfer basket containing the items to be cleaned was lowered into the immersion sump , and statically (i.e. no liquid flow) sonicated for a finite pe-riod of time, usually 15 minutes. f. After static sonication, the rinse pump was turned on and the liquid in the immersion bath was circulated through the activated carbon columns at a rate of1,700 ml/minute for a finite period of time. The circulation time ranged fro m 15 minutes to 2 hours, depending on the purpose of the test. g. The rate of decontamination was monitored by following the concentration of the contaminant in the decontamination liquid (HFE-7100). h . Steps e and f were repeated until the presence of contaminant in the circulat-ing liquid could no longer be detected. i. When the immersion sump liquid was free of contaminant, the transfer basket was moved from the immersion sump to the superheat sump and dried for 30 minutes to remove liquid drag out. j . The transfer basket was removed from the Poly-Kleen™ system. The test pieces were removed from the basket, visually examined, photographed under visible and UV light, reweighed, and archived. I n order to maximize ultrasonic power density, the minimum amount of liquid needed to cover the parts being cleaned was used. Typically, the sump contained from 130 to 180 mm (5 to 7 inches) of liquid, which corresponds to a liquid vol-ume of approximately 15 liters to 30 liters (4 to 8 gallons) and a corresponding ul-trasonic power density of 26 to 18 watts/liter (100 to 70 watts/gallon). In prelimi-nary tests, it was noted that immersing and sonicating the test samples when the immersion sump was filled to the brim (about 53 liters (14 gallons)) did not result in effective cleaning. At that volume, the ultrasonic power density had dropped to a value of 8 watts/liter (30 watts/gallon). While this value would be considered marginal in a stainless steel ultrasonic bath, where the ultrasonic waves can be re-flected from the walls back into the liquid, in a polypropylene bath in which the walls absorb rather than reflect the ultrasonic waves, this power density level is too low. If parts were also contaminated with biological agents, after Step h, they would be sonicated in a fluorinated surfactant/HFE-7100 solution that would be circu-lated through microfilters to remove suspended materials. The parts would then be rinsed in fresh HFE-7100 to remove fluorocarbon surfactant residues, and then dried as described above. Table 3 lists the sensitive equipment decontamination experiments that were carried out in the Poly-Kleen™ system during the course of the program. The combination of equipment processed, contaminants used, and monitoring method(s) examined are listed in this table. The results of the various cleaning re-sults are summarized in Table 4. This table records the weights of the items listed in Table 3, before and after contamination, as well as the post-cleáning weight and visual appearance of these items.
ABSTRACT
Except for the runs where there was visible attack of the substrate by the simulant (as in run 1 in Table 3), there was an increase of less than a 0.1 gram in the weight of the object after contamination and cleaning and the original (i.e. before contamination) weight of this object. In some cases, there was a weight loss of the order of 0.1 gram (as in the calculator in run 6 and the pistol in run 9). This was attributed to the removal of other soils that were previously present on these test items.