Table 3-5. M easured ARFs and RFs During the Venting of Superheated Aqueous Solutions

DOE-HDBK-3010-94

3.0 Liquids; Aqueous Solutions

Table 3-5. M easured ARFs and RFs During the Venting of Superheated

Aqueous Solutions

(Tables A.3 and A.4 - Ballinger, Sutter and Hodgson, M ay 1987)

Source

Pressure, psig

ARF

ARF x RF

Volum e, m l

700

125

1.0E-2

0.78

1.0E-2

350

240

5.0E-2

0.73

4.0E-2

125

2.0E-2

0.66

1.0E-2

9.0E-3

0.62

6.0E-3

125

9.0E-2

0.69

6.0E-2

100

solutions were heated to pressures of 0.39 MPa (57 psig at ~134 oC), 0.85 MPa

(124 psig at ~161 oC) and 1.65 MPa (240 psig at ~202 oC) using source volumes of

700 cm3, 350 cm3 and 100 cm3. Figure 3-6 reproduced from Ballinger, Sutter and

Hodgson (May 1987) indicates the temperature of the aqueous solution at the stated

pressures although the extrapolation to the lower temperature/pressure is questionable

given datum point #5. The uncertainty at these lower values, however, does not pose

any significant concern. The liquid was released from the open top of the ~4-in.

diameter apparatus via a double rupture disk arrangement. The experimental

apparatus is shown schematically in Figures A.5 and A.6 in Appendix A. The

fraction airborne increased with initial pressure and decreasing source size. The

highest ARF, 9E-2, was measured at 0.85 MPa using a 100 cm3 source and 69% of

the airborne material was in the respirable size fraction. The ARF and RF depend

upon the amount of heat (sensible heat in the liquid plus in the container) available

and the heat needed to vaporize the solvent. The greater the fraction of solvent that

can be flashed, the larger the ARF and RF. The ARFs and RFs measured are

tabulated in Tables A.8 and A.9 in Appendix A.

Two bounding values are selected. For relatively low energy liquids with

temperatures greater than the boiling point but less than 50 oC superheat, bounding

ARF and RF values are assessed to be 1E-2 and 0.6 based on the 60 psig

experimental run in Table 3-5. For more severe conditions between 50 and 100 oC

superheat, bounding values for ARF and RF are assessed to be 1E-1 and 0.7. Median

values for these conditions are 2E-2 and 0.7 with average values of 4E-2 and 0.7.

B. E m p irical C orrelation s/M od els. For situations where the temperature of the

liquid released exceeds 100 oC superheat, an empirical correlation was presented by

Ayer et al. (May 1988) for the evaporation/settling corrected data for the flashing

spray experiments performed by Ballinger, Sutter and Hodgson (May 1987):

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