1 Scope
This part of JB/T 8941 specifies the performance test methods of roots type blower for general purpose (hereinafter referred to as blower).
This part is applicable to performance test of roots type blower for general purpose. For blower with special working condition as well as being used for conveying special gas, the performance test may be carried out by making reference to this standard.
2 Normative References
The following documents for the application of this document are essential. Any dated references, just dated editions apply to this document. For undated references, the latest editions (including any amendments) apply to this document.
GB/T 2624.2-2006 Measurement of Fluid Flow by Means of Pressure Differential Devices Inserted in Circular Cross-section Conduits Running Full - Part 2: Orifice Plates
GB/T 2888 Methods of Noise Measurement for Fans Blowers Compressors and Roots Blowers
GB/T 6075.1-2012 Mechanical Vibration-Evaluation of Machine Vibration by Measurements on Non-rotating Parts-Part 1: General Provisions
JB/T 8941.1 Roots Type Blower for General Purpose - Part 1: Specification
3 Terminologies and Definitions
For the purposes of this document, the following terminologies and definitions apply.
3.1
Standard inlet point
The typical inlet point for each kind of blower, which varies from the structure and configuration of blower.
Note 1: the standard inlet point of single-stage blower is the point of inlet flange.
Note 2: the standard inlet point of the double-stage blower is the point of the first-stage blower's inlet flange.
Note 3: the standard inlet point of the blower package is the inlet initial end of blower.
3.2
Inlet condition
Foreword I
1 Scope
2 Normative References
3 Terminologies and Definitions
4 Symbols, Units and Subscripts
5 Measuring Methods and Accuracy
5.1 Pressure Measurement
5.2 Temperature Measurement
5.3 Humidity Measurement
5.4 Rotational Speed Measurement
5.5 Measurement of Flow Rate
5.6 Power Measurement
5.7 Vibration Measurement
5.8 Noise Measurement
5.9 Other Measurements
5.10 Instrument Calibration
6 Test Methods
6.1 Test
6.2 Test Apparatuses
6.3 Reading Examination
6.4 Test Result Calculation
7 The Comparison between Test Results and the Specified Values
8 Test Report
Appendix A (Normative) Discharge Coefficient and Swellability Coefficient
A.1 Discharge Coefficient C
A.2 Swellability Coefficient ε
Appendix B (Informative) Water Vapor Pressure
Figure 1 Test Apparatuses of Positive Pressure Blower
Figure 2 Test Apparatuses of Negative Pressure Blower
Figure 3 Test Apparatus of Blower Package
Figure 4 Structure of Pressure Port
Table 1 Symbols and Units
Table 2 Subscripts
Table 3 The Accuracy of Measuring Instruments
Table 4 Transmission Efficiency
Table 5 Deviation Between the Test Conditions and Specified Working Conditions
Table A.1 The Discharge Coefficient C When the Angle Joint Tapping Orifice Plate Dn≥71.12mm
Table A.2 Dynamic Viscosity of Air
Table A.3 Coefficient of Swellability ε
Table B.1 Water Vapor Pressure in Saturated Air under 1×105Pa
