Table D3. Pressure loss and air flows through Dust Director vacuum cleaner 10-04-2007 Round 1

Before (B) or after (A) adding 5 pounds

Total weight of debris transferred (lb)

Venturi meter δP (inches of water)

Static Pressure Measurements with manometer (inches of water) ¹

Absolute pressures measured with pressure transducers (psi)

Time to start loading

Time to stop loading

Air flow (cfm)

Pressure in vacuum cleaner bag (inches of water)

Pressure after the bag (inches of water

Pressure after first filter (inches of water)

Pressure after second filter (inches of water)

Pressure after the bag (psi) 87614

Pressure after first filter (psi) 53748

Pressure after second filter (psi) 55481

B

5.2

7.9

 -3.7

-7.2

-8.4

-12

14.152

13.865

13.723

1:47pm

1:50pm

73.95

A

6

-2.6

-6.5

-35.7

-38.9

14.043

12.979

12.881

64.51

B

10.4

5.5

 -3.5

-5.6

-34.7

-38

14.202

12.891

12.754

2:08pm

2:09pm

61.76

A

3.5

-1.3

-6.8

-50.6

-53.3

14.177

12.328

12.224

49.19

B

15.4

3.4

 -1.5

-6.1

-50

-52.6

14.177

12.344

12.232

2:22pm

2:23pm

48.47

A

2.5

-1.5

-8.5

-57.8

-59.9

14.11

12.069

11.938

41.46

B

20.4

2.8

 -1.6

-8.8

-55.6

-58.1

14.11

12.144

12.022

2:34pm

2:35pm

43.92

A

1.2

-1

-14.1

-63.9

-65.9

13.993

11.843

11.752

28.48

B

25.8

2

 -1.1

-12.4

-62.5

-64.5

14.002

11.885

11.786

2:44pm

2:45pm

37.00

A

1.4

-0.85

-16.9

-66.5

-68.4

13.968

11.743

11.651

30.82

B

30.8

1.95

-1.1

-12.8

-62.2

-63.9

14.01

11.902

11.803

2:56pm

2:57pm

36.52

A

1.2

-0.9

-18.2

-68.4

-70

13.876

11.684

11.584

28.48

B

36

3.6

 -2.2

-12

-49.8

-52.5

14.085

12.361

12.409

3:09pm

3:10pm

49.90

A

1.8

-1.2

-19.3

-63.9

-65.9

13.885

11.843

11.736

35.06

Final

 36

3.5

-2

-13.5

-51.3

-54.2

13.977

12.303

12.157

3:18pm

49.19

¹ Static pressure is the difference in pressure from atmospheric pressure. These static pressures are less than atmospheric pressure