1、BRITISH STANDARD BS4531:1986 Specification for Portable and mobile troughed belt conveyors UDC 621.867.218182.3/.4BS4531:1986 This British Standard, having been prepared under the directionof the Mechanical Handling Standards Committee, was published under the authorityof the Board of BSI andcomes i
2、nto effect on 30 May1986 BSI 08-1999 First published December1969 First revision May1986 The following BSI references relate to the work on this standard: Committee reference MHE/9 Draft for comment84/72596 DC ISBN 0 580 14883 1 Cooperating organizations The preparation of this British Standard was
3、entrusted by the Mechanical Handling Standards Committee (MHE/-) to Technical Committee MHE/9 upon which the following bodies were represented: Amalgamated Union of Engineering Workers Associated Offices Technical Committee Association of British Mining Equipment Companies Association of Consulting
4、Engineers British Aggregate Construction Materials Industries British Rubber Manufacturers Association British Steel Industry Coke Oven Managers Association Cranfield Institute of Technology Department of Trade and Industry (Mechanical and Electrical Engineering Division) Electrical, Electronic, Tel
5、ecommunications and Plumbing Union Engineering Equipment and Materials Users Association Health and Safety Executive Institution of Mining Engineers Institution of Production Engineers Mechanical Handling Engineers Association Metal Packaging Manufacturers Association National Coal Board National In
6、stitute of Agricultural Engineering Society of Dairy Technology Solids Handling and Processing Association Amendments issued since publication Amd. No. Date of issue CommentsBS4531:1986 BSI 08-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Definitions 1 3 Belt
7、ing 2 4 Take-up devices 2 5 Pulleys (including motorized pulleys) 5 6 Idlers 6 7 Power units 7 8 Skirt plates 7 9 Luffing gear 7 10 Lubrication 7 11 Walkways and access stairways 7 12 Radial conveyors 7 13 Belt cleaning 7 Appendix A Nominal cross-sectional area of load stream and nominal belt carryi
8、ng capacity 8 Figure 1 Typical portable troughed belt conveyor 3 Figure 2 Typical mobile troughed belt conveyor with fixed discharge height 3 Figure 3 Typical mobile troughed belt conveyor with adjustable discharge height 4 Figure 4 Typical crowned pulley profile 6 Figure 5 Load stream areas with tw
9、o- and three-roll idlers 8 Table 1 Minimum belt edge clearance 2 Table 2 Minimum pulley face length 5 Table 3 Minimum pulley diameter in relation to belt construction 6 Table 4 Nominal diameters of idler rollers 6 Table 5 Surcharge angle 8 Table 6 Values of terms related to surcharge angle S and tro
10、ughing angle A 9 Publications referred to Inside back coverBS4531:1986 ii BSI 08-1999 Foreword This revision of this British Standard has been prepared under the direction of the Mechanical Handling Standards Committee. It supersedes BS4531:1969 which is withdrawn. It applies to portable and mobile
11、troughed belt conveyors, and is a companion standard to BS2890. This revision specifies more detailed requirements for pulley and idler lengths than the earlier edition. The relationship between specified dimensions and those in the relevant ISO standard are also now given in this standard. For safe
12、ty precautions only handrails have been included in this revised standard. Safety requirements and statutory requirements will be the subject of a future code of practice. The attention of users of this standard is drawn to the need to comply with all the statutory instruments and regulations approp
13、riate to the equipment, its siting and use, covered by this standard. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immu
14、nity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to10, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the am
15、endment table on the inside front cover.BS4531:1986 BSI 08-1999 1 1 Scope This British Standard specifies requirements for portable and mobile troughed belt conveyors, in particular for their belting, pulleys and power units, together with requirements for ancillary items. Requirements for belting o
16、nly apply to belts with a smooth or patterned surface. NOTE 1Equations for calculating the belt carrying capacity are given in Appendix A. NOTE 2The titles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this British Standard th
17、e following definitions apply. 2.1 portable conveyor a conveyor designed to be lifted and moved as a unit from one position to another NOTEA typical portable troughed belt conveyor is shown in Figure 1. 2.2 mobile conveyor a conveyor on wheels, crawlers, skids or pontoons NOTETypical troughed belt m
18、obile conveyors are shown in Figure 2 and Figure 3. 2.3 head of the conveyor the discharge end of the conveyor 2.4 tail of the conveyor the loading end of the conveyor 2.5 carrying idler an idler which supports the loaded belt. An assembly of one or more carrying idlers comprises a carrying idler se
19、t 2.6 impact idler an idler which supports the loaded belt at the feed point of the conveyor and is usually covered with rubber to absorb the impact of the material being fed 2.7 return idler an idler which supports the empty side of the belt. An assembly of one or more return idlers comprises a ret
20、urn idler set 2.8 take-up device the device for taking up slack and applying tension to the belt 2.9 anti-run-back device an automatic device for preventing a loaded elevating conveyor belting running backwards 2.10 driving pulley the pulley which drives the belt 2.11 snub pulley the pulley used to
21、develop the necessary arc of contact (angle of wrap) of the belt on the driving pulley 2.12 bend pulley the pulley used to change the direction of the belt 2.13 head pulley the terminal pulley at the head of the conveyor 2.14 tail pulley the terminal pulley at the tail of the conveyor 2.15 take-up p
22、ulley the travelling pulley used in the take-up device 2.16 drive the equipment which drives the belt consists of a power unit, transmission and driving pulley 2.17 power unit the conveyor power source, e.g.an electric motor, internal combustion engine, motorized pulley etc. 2.18 transmission the as
23、sembly of devices coupling the power unit to the driving pulley for driving the belt at the desired speed 2.19 handing of conveyor the designation of the sides of a unidirectional conveyor, e.g.left or right, when viewed from the tail to the head of the conveyor 2.20 brake a device for bringing the
24、belting of the conveyor to rest and maintaining it at restBS4531:1986 2 BSI 08-1999 2.21 scraper a device fixed or flexibly mounted across the width of a belt or pulley of a conveyor, for removing adherent material 2.22 chute a straight or curved, open-topped or enclosed, smooth trough by which mate
25、rials are directed and lowered by gravity 2.23 safeguard a guard or device designed to protect persons from danger 2.24 feed boot a three-sided trough for feeding material centrally on to the belt 2.25 feed hopper a three- or four-sided extension to the feed boot, fitted to the conveyor or free stan
26、ding, for receiving material in bulk from the loading device, e.g.a lorry, tractor, shovel 2.26 skirt plate an extension to the feed boot along the length of the conveyor for centralizing and/or retaining material on the belt 2.27 decking plate the plate between the top and bottom strands of the bel
27、t for preventing spillage on to the return strand 2.28 belt edge clearance the clearance between each edge of the belt and the conveyor structure or any obstacle 2.29 profile pitch length the distance between repeats of the consecutive patterns of the patterned surface of some inclined belts 3 Belti
28、ng NOTEBelts having cleats or chevrons on the carrying surface are designed to increase the effective conveyor inclination, depending on the height of cleat or chevron and the material being conveyed. Certain limitations occur in pulley diameters and configurations with the use of cleats or chevrons
29、, and these are noted in the text. 3.1 Belt width The belt width shall be selected from the following: 3.2 Belt length 3.2.1 Belting which is ordered to a definite open-ended length shall be supplied with a tolerance on its length of in accordance with BS490-1. 3.2.2 The length of a belt supplied in
30、 the spliced endless form (net endless length) shall not vary by more than0.5%from the specified length in accordance with BS490-1. 3.2.3 In the case of moulded profile belts the net endless length shall be a multiple of the profile pitch length. 3.3 Belt edge clearance The minimum belt edge clearan
31、ce shall be as given in Table 1, as appropriate. Table 1 Minimum belt edge clearance 3.4 Belt capacity The nominal belt carrying capacity, calculated using Appendix A, shall be stated, together with the value of all the variables used in the calculation. The nominal belt carrying capacity shall be s
32、uch that the conveyor will operate without spillage. NOTEThe belt width and speed (upon which the belt carrying capacity depends) should be chosen to suit the particular application, with due regard to the nature, size grading, characteristics and surcharge angle of the material to be handled. 4 Tak
33、e-up devices 4.1 The conveyor shall be equipped with a take-up device to ensure adequate belt tension for driving, to limit belt sag to2%of the belt span between carrying idlers, and to compensate for variations in belt length. 300mm 400mm 450mm a 500mm 600mm 650mm 750mm a 800mm 900mm a 1000mm 1050m
34、m a 1200mm a The belt widths marked with an asterisk should only be used for replacement belting on existing conveyors; they are not recommended for new designs and are not specified in ISO251. Belt width Minimum clearance mm 300 to650 750 to1200 mm 50 75 +2% 0%BS 4531:1986 BSI 08-1999 3 Figure 1 Ty
35、pical portable troughed belt conveyor Figure 2 Typical mobile troughed belt conveyor with fixed discharge heightBS 4531:1986 4 BSI 08-1999 Figure 3 Typical mobile troughed belt conveyor with adjustable discharge heightBS4531:1986 BSI 08-1999 5 NOTEThe most frequently used device is a screw operated
36、adjustment manually effected by means of two screws acting upon the pulley bearings. 4.2 The length of adjustment shall take account of the working tension, the characteristics of the belt and the method of joining. 4.3 After initial setting up sufficient adjustment shall remain to compensate for be
37、lt stretch during normal working life. 5 Pulleys (including motorized pulleys) 5.1 Pulley face length The pulley face length, which shall be greater than the belt width to take account of any belting tolerances and misalignment, shall be selected from the lengths given in Table 2, as appropriate. Ta
38、ble 2 Minimum pulley face length 5.2 Pulley diameters NOTEA typical crowned pulley profile is shown in Figure 4. 5.2.1 General. The nominal diameter of a flat or crowned pulley (D1) shall exclude the thickness of any pulley lagging. The nominal diameter of a crowned pulley is its maximum diameter (D
39、1). 5.2.2 Diameter in relation to belt construction. The minimum pulley diameters for belts of different carcass thickness shall be as given in Table 3, as appropriate. NOTEThe use of pulleys with diameters that are too small for the carcass thickness and construction of the belt may lead to prematu
40、re failure of the belt. The pulley diameters shown are satisfactory for the recommended maximum belt tension (RMBT). If the belt is to operate at an anticipated maximum tension which is lower than its recommended maximum belt tension (RMBT), the appropriate belt tension figure shall be chosen from c
41、olumn1 of Table 3. NOTEIf metal fastener joints are to be used, these should be selected to suit the pulley diameter. Care should be taken to provide driving pulleys of sufficient diameter to ensure adequate traction. 5.3 Pulley profiles The pulley surface shall have a flat or crowned profile depend
42、ing upon the application. The crown profile shall be regular and symmetrical about the centre of the pulley face width. The nominal diameter (D1) shall not exceed the edge diameter (D2) by more than1%of the pulley face width (L). NOTE 1A typical crowned pulley profile is shown in Figure 4. NOTE 2Cro
43、wning should not be applied to snub or bend pulleys. 5.4 Pulley shell thickness The thickness of the pulley shell shall be such that the pulley shall resist buckling due to the belt tension and failure due to wear or corrosion. 5.5 Pulley bearing life Bearings shall be designed to give a minimum wor
44、king life of25000h for conveyors which are being used up to16h per day and50000h for conveyors used over16h per day. Belt width Minimum pulley face length mm 300 400 450 500 600 650 750 800 900 1000 1050 1200 mm 400 500 a 550 600 a 700 750 a 900 950 a 1050 1150 a 1200 1350 a Preferred sizes in accor
45、dance with ISO1536.BS4531:1986 6 BSI 08-1999 Table 3 Minimum pulley diameter in relation to belt construction 6 Idlers 6.1 Idler roller diameters The nominal diameters of idler rollers shall be selected from those given in Table 4, as appropriate. Table 4 Nominal diameters of idler rollers 6.2 Idler
46、 pitch The spacing of the carrying idlers is determined by the characteristics of the belt, the volume, density and granularity of the material to be conveyed and shall be such that the sag of the belt between the idlers does not exceed2%of the belt span so as to ensure good belt life, prevent spill
47、age and keep friction to a minimum. Anticipated maximum belt tension per unit width Nominal belt carcass thickness u u2mm 2mm tou u3mm 3mm tou u4mm 4mm tou u5mm 5mm tou u 6.5mm Minimum pulley diameter A B C A B C A B C A B C A B C N/mm 8 and below 10 12.5 16 20 25 32 40 50 63 80 100 mm 160 160 200 2
48、00 200 250 250 315 mm 160 160 160 160 200 200 250 250 mm 160 160 160 160 160 200 200 200 mm 200 200 200 200 250 250 315 315 400 mm 160 160 200 200 200 250 250 315 315 mm 160 160 160 160 200 200 200 250 250 mm 200 250 250 250 315 315 315 400 400 400 mm 200 200 200 250 250 250 315 315 315 400 mm 160 2
49、00 200 200 200 250 250 250 315 315 mm 250 250 315 315 315 400 400 400 500 500 mm 200 250 250 250 315 315 315 400 400 400 mm 200 200 200 250 250 250 315 315 315 400 mm 315 315 400 400 400 500 500 500 500 mm 250 315 315 315 400 400 400 500 500 mm 250 250 250 315 315 315 400 400 400 Key A stands for driving pulleys and head pulleys. B stands for non-driving pulleys (terminal, take-up snub and bend pulleys) where belt tension may exceed60%of anticipated maximum. C stands for non-driving pulleys (terminal, take-up snub and bend pulleys) w
