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1、SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefr
2、om, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2002 Society of Automotive Engineers, Inc. All rights reserved. No part of
3、this publication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER:Tel: 877-606-7323 (inside USA and Canada) Tel: 724-776-4
4、970 (outside USA) Fax: 724-776-0790 Email: custsvcsae.org SAE WEB ADDRESS:http:/www.sae.org SURFACE VEHICLE STANDARD J1792-2 REV. AUG2002 Issued1996-09 Revised2002-08 Superseding J1792-2 SEP1996 Self-Propelled SweepersAir Flow Performance Part 2: Suction/Blower Fan Performance ForewordThe only chang
5、es to this document were to Equation 5 and Figure 5. Some of the information from Equation 6 was inadvertently used in Equation 5 when the documents were converted for Electronic purposes. Some of Figure 5 was missing. 1.ScopeThis SAE Standard establishes a test method and a definition for disclosin
6、g the performance of suction/blower fans when applied to self-propelled sweepers that solely use a pneumatic conveyance means for the collection and transfer of “sweepings” into a collection hopper. 1.1PurposeThe purpose of the document describes a test practice for measuring the performance of suct
7、ion/ blower fans used in vacuum and regenerative air street sweepers. The measured performance considers the air volume movement versus the static depression developed by the fan across a spectrum of different operating conditions. The document also sets-out to propose a format for the presentation
8、of the test results. The method in this document can be used to disclose or compare particular operating performance criteria under similar conditions. 2.Reference 2.1Applicable PublicationThe following publication forms a part of the specification to the extent specified herein. Unless otherwise in
9、dicated, the latest issue of SAE publications shall apply. 2.1.1SAE PUBLICATIONAvailable from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001. SAE J2130Self-Propelled Sweepers 3.Definitions 3.1SweeperA self-propelled vacuum or regenerative air street sweeper that is primarily designed to swee
10、p material from highways, parking lots, airport complexes, industrial and construction sites, and during road maintenance work. The sweeper may use broom means to dislodge and direct material into a pneumatic collection mechanism that is the sole means to convey the swept material into a collection
11、hopper. 3.2Suction/Blower FanCentrifugal fan means for developing the required air movement/pressure employed in the sweepers pneumatic conveyance mechanism. SAE J1792-2 Revised AUG2002 -2- 4.Technical Requirements 4.1Apparatus RequiredManometer - Pitot tube - Tachometer - Thermometer - Barometer -
12、Hygrometer (see note in 4.4) - test duct. 4.2MethodThe machine shall be set up in its optimum running condition according to the recommendations given in its operators instruction manual. The hopper filter meshes shall be clean or may be removed. All air ducts shall be clean and free from debris. Wa
13、nder hoses, drain off hoses, etc., shall be sealed and blanked- off. The suction pick-up nozzle and flexible conduit shall be removed and substituted with a test duct, a suggested test duct and blanking mechanism is shown in Figures 1 and 2. It is important to monitor the engine and suction/blower f
14、an speed during the test in order that it always runs at a constant speed. Ideally a digital tachometer connected to the engine or actual fan itself shall be used. An instrument giving a precise speed to the nearest revolution per minute is preferred. The running speed of the fan shall be set to a p
15、redetermined level for the test and recorded in the results. The manometer and pitot tube used in the tests measurements shall be checked to ensure the pitot tube is clean and that the manometer and connecting tubes are perfectly sealed with no leakage to atmosphere. If an electronic manometer is us
16、ed, first ensure that it is calibrated to zero pressure in the inert state. Two small holes shall be provided at 90 degrees to each other in the test duct large enough to permit the insertion of the pitot tube. These holes shall be located mid-way along the test duct to ensure minimum turbulence wit
17、hin the air-stream. FIGURE 1SUGGESTED TEST DUCT FIGURE 2TEST DUCT SET-UP SAE J1792-2 Revised AUG2002 -3- The ambient temperature shall be recorded before and after the tests in order that results may be corrected to a standard of 20 C (68 F). Barometric pressure shall also be recorded so that correc
18、tions may be made to a standard of 760 mm Hg or 1013 mb (norm at sea level). Corrections for temperature and barometric pressure will ensure that quantifiable comparative data is available to a common standard. The pitot tube shall have a calibrated scale marked with six positionsrefer to Figure 3,
19、according to the internal size of the test duct being used. The pitot tube is then inserted into the test duct with the probe pointing into the air-stream within 5 degrees of the duct axis. Velocity head pressure readings are then read from the manometer at each of the twelve positions, six for each
20、 pass (or hole). Readings taken are the total velocity head (in millimeters water gauge), shown on the manometer. From these twelve results, the average velocity head and hence air flow velocity and volume shall be calculated based on the ducts cross-sectional area. Prior to and after the test pass,
21、 the static pressure within the eye of the fan shall be recorded. The test process shall be repeated a number of times, each time with the test duct inlet progressively blanked by moving it nearer to the ground to reduce and inhibit air flow into it. Each time the negative pressure within the eye of
22、 the fan shall be recorded before and after each test pass. Care must be taken while measuring the velocity head readings to ensure that the pitot tube is held parallel to the walls of the duct. This may be checked by reference to the direction pointer on the tail of the pitot tube (this points in t
23、he same direction to the pitot probe). The static depression shall also be measured within the duct in order to make a correction for air density by connecting the side holes in the pitot tube only to the manometer, leaving the other side open to atmosphere. The total deflection (in millimeters wate
24、r gauge) shall again then be read from the manometer. Note that in this application the reading will be a negative pressure and shall be used as such when applying the formulae for correction of duct depression. FIGURE 3PITOT TUBE POSITIONS FOR A SIX-POINT PASS IN CIRCULAR DUCTS SAE J1792-2 Revised
25、AUG2002 -4- 4.3Results TabulationThe test results can be typically recorded in the format shown in Figure 4, the corrected values would be derived by the calculation methods given in 4.4. FIGURE 4RESULTS CALCULATION 4.4CalculationsSee Equations 1 to 6. (Eq. 1) (Eq. 2) (Eq. 3) (Eq. 4) (Eq. 5) (Eq. 6)
26、 NOTE Corrections may also be made for relative humidity conditions. Usually the results shall be specified at 50% humidity. High humidity will result in lower air volume recordings due to lower density. The effect is often small and can therefore be ignored. Average velocity head (in mm H2O) 2 n 12
27、 -= Correction for temperature (correct to 20 C) ambient temp. (C) + 273 293 -= Correction for barometric pressure (correct to 1013 mbsea level) 1013 barometric pressure (mb) -= Correction for duct depression (correct to std. density) 10363 10363 + static depression (mm H2O) in test duct -= Air velo
28、city in duct (m/s) 4.0321( )2( )3( )4( ) (multiply by 196.8 to convert m s to ft / min) = Volume of conveying air (m3s) (5)duct cross section m2() multiply by 2118.9 to convert m3s to cfm() = SAE J1792-2 Revised AUG2002 -5- 4.5Typical Test Summary FormatThe calculated results for corrected air flow
29、volume versus the negative air pressure (static pressure) within the fan eye may be shown graphically and presented together with the operational criteria in the format in Figure 5: FIGURE 5TYPICAL TEST SUMMARY FORMAT SAE J1792-2 Revised AUG2002 -7- APPENDIX A (INFORMATIVE) (BIBLIOGRAPHY) A.1The fol
30、lowing references are made to these documents which only serve for information and have merely served as a reference in the preparation of this document. ANSI/AMCA 210-85American National Standard LaboratoryMethods of testing fans for rating ISO3966:1977Measurement of fluid flow in closed conduitsVe
31、locity area method using pitot static tubes ISO7194:1983Measurement of fluid flow in closed conduitsVelocity area method of flow measurement in swirling or asymmetric flow conditions in circular ducts by means of current meters or pitot static tubes SAE J1792-2 Revised AUG2002 RationaleThe only chan
32、ges to this document were Equation 5 and Figure 5. Some of the information from Equation 6 was inadvertently used in Equation 5 when the documents were converted for Electronic purposes. Part of Figure 5 was missing. Relationship of SAE Standard to ISO StandardNot applicable. ApplicationThe SAE Stan
33、dard establishes a method of disclosing the suction air volume and suction/blower fan performance of self-propelled sweepers that use pneumatic conveyance means for the transfer of “sweepings” into a collection hopper. Reference Section SAE J2130Self-Propelled Sweepers Developed by the SAE Machine Technical Committee SC2Sweeper, Cleaner, and Machinery Sponsored by the SAE Machine Technical Committee