1、PD CEN/TR13930:2009ICS 23.080NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWPUBLISHED DOCUMENTRotodynamic pumps Design of pump intakes Recommendationsfor installation ofpumpsIncorporatingcorrigendumJune 2010National forewordThis Published Document is the UK implementation of C
2、EN/TR 13930:2009, incorporating corrigendum June 2010.The UK participation in its preparation was entrusted to Technical Committee MCE/6, Pumps and pump testing. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to in
3、clude all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.PD CEN/TR 13930:2009This Published Document was published under the authority of the Standards Policy and Strategy Comm
4、ittee on 28 February 2009 BSI 2010Amendments/corrigenda issued since publicationDate Comments 31 August 2010 Implementation of CEN/TR corrigendum June 2010; Figure 23 a) replacedISBN 978 0 580 71461 0TECHNICAL REPORTRAPPORT TECHNIQUETECHNISCHER BERICHTCEN/TR 13930January 2009ICS 23.080 Supersedes CR
5、 13930:2000 English VersionRotodynamic pumps - Design of pump intakes -Recommendations for installation of pumpsPompes rotodynamiques - Conception des ouvragesdaspiration - Recommandations dinstallation des pompesKreiselpumpen - Gestaltung der Einlaufbauten -Empfehlungen zur Installation der PumpenT
6、his Technical Report was approved by CEN on 13 October 2008. It has been drawn up by the Technical Committee CEN/TC 197.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, I
7、taly, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: Avenue Marnix 17, B-1000 B
8、russels 2009 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. CEN/TR 13930:2009: EIncorporating corrigendum June 2010PD CEN/TR 13930:2009CEN/TR 13930:2009 (E) 2 Contents Page Foreword 3Introduction . 41 Scope 52 General 52.1 Factors whic
9、h influence the operation of the plant . 52.2 General design principles for a pumping plant 63 Plant with vertical suction inlet 73.1 General arrangements . 73.2 Diameter (D) at the entrance of the bellmouth or the tapered suction. 93.3 Distance (C) between the bellmouth or the tapered suction inlet
10、 and floor 103.4 Distances between suction inlet axis and walls . 113.4.1 Distance (L) between suction inlet axis and side walls . 113.4.2 Distance (E) between suction inlet axis and rear wall . 113.5 Submergence (S) . 113.5.1 Conditions to be satisfied for the determination of submergence . 113.5.2
11、 Determination of submergence (S) 123.6 Strainer . 123.7 Feed intake - Pump environment . 133.7.1 Feed intake . 133.7.2 Immediate environment of the pump . 203.8 Case of pumping plant with vertical suction inlet and flow rate less than 50 m3/h 234 Plant with intake with top suction inlet . 235 Plant
12、 with intake with floor suction inlet . 245.1 Bellmouth . 255.2 Submergence of horizontal plate . 255.3 Special anti-vortex devices . 256 Plant with intake with wall suction inlet 256.1 Shape and position of suction inlet . 256.2 Submergence . 276.3 Special anti-vortex devices . 27Bibliography 29PD
13、CEN/TR 13930:2009CEN/TR 13930:2009 (E) 3 Foreword This document (CEN/TR 13930:2009) has been prepared by Technical Committee CEN/TC 197 “Pumps”, the secretariat of which is held by AFNOR. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent ri
14、ghts. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes CR 13930:2000. PD CEN/TR 13930:2009CEN/TR 13930:2009 (E) 4 Introduction In addition to the risks of cavitation that may exist at the intake of any pump depending on the NPSH
15、 available, pumping from a sump poses specific problems. In fact, if the water passes from a flow state with an exposed surface to flow under pressure, significant swirling movements may occur and sometimes be amplified, thus creating a sort of funnel or vortex which opens out into the exposed surfa
16、ce of the sump with a risk of air being entrained or creating a swirling chimney, or whirl between the bottom and the intake producing degassing or vaporisation of the liquid in the entrance of the pump (see Figures 1a) and 1b) below). These phenomena, which are generally unsteady, can have unwanted
17、 effects on the plant: undesirable vibration of various pump components; increased risk of cavitation; drop in efficiency; reduction in flow rate and/or head; risk of floating bodies being sucked in; intense and irregular noise. Compliance with the recommendations in this document makes it possible,
18、 in most commonly encountered industrial applications, to avoid or at least limit the phenomena mentioned above. 1a) Vortex causing entrainment of air in suction piping 1b) Chimney or whirl between the floor and the suction inlet Figure 1 Types of possible disturbances PD CEN/TR 13930:2009CEN/TR 139
19、30:2009 (E) 5 1 Scope 1.1 This technical Report contains recommendations for the design of pump intakes and the installation of pumps. As far as possible, these recommendations should be adhered to in order to obtain correct operation of the plant. These recommendations are applicable regardless of
20、the flow rate of the plant: plant which works with clear water (or relatively unclouded) and relatively non-aerated water or any other liquid having physical and chemical properties which are similar to those of water; NOTE This document nevertheless contains several general recommendations for oper
21、ation with cloudy (or very cloudy) water. pumping plant which has its own floor. 1.2 This document deals with various intake configurations: Clause 3 contains recommendations which apply to intakes with vertical suction inlet; Clause 4 contains recommendations applicable to intakes with top suction
22、inlet; Clause 5 contains recommendations applicable to intakes with floor suction inlet; Clause 6 contains recommendations applicable to intakes with side-wall suction inlet. 2 General 2.1 Factors which influence the operation of the plant The following factors have an effect on the operation of the
23、 plant: a) Characteristics and position of the suction inlet: arrangements of the suction inlet (vertical with bellmouth or tapered suction, top, floor or side-wall intake); presence or absence of a bellmouth or tapered suction; distance between suction inlet and floor; distance between suction inle
24、t and side-walls; submergence (level of liquid relative to suction inlet); strainer. b) Inflow of liquid to the intake: inflow velocity of the liquid; shapes and dimensions of inflow; PD CEN/TR 13930:2009CEN/TR 13930:2009 (E) 6 position of inflow. c) Environment of the pump in the plant: velocity of
25、 liquid close to the pump; shapes and dimensions of the plant; special devices (gratings), anti-vortex device; relative positions of pumps to each other and in the plant. Clauses 3 to 6 below contain recommendations concerning the determining factors for each arrangement of the suction inlet. NOTE I
26、f the liquid is charged with solid particles in suspension, the following recommendations may be amended. Prevent the velocity of the fluid falling below a value which allows the deposition of solid materials. A minimum value of 0,7 m/s close to the suction inlet is currently admitted. 2.2 General d
27、esign principles for a pumping plant In order for the pump to be fed under the best possible conditions, effort should be made to obtain a permanent, uniform and even flow in the suction pipe. To achieve this, it is necessary to: supply the suction pipe for each pump with a balanced flow which is fr
28、ee from swirl; ensure that the water accelerates gradually along the intake; any deceleration generates flow instabilities; avoid any entrainment of air by suction (vortex) or by churning (weir). Ensure that these conditions are adhered to as closely as possible regardless of the operating condition
29、s of the plant (one or more pump(s) working, one or more intake sluice(s) or filter(s) in service, high water level or low water level, etc.). The stipulations in the following clauses are aimed at achieving this. In those, inevitably numerous, situations that are not dealt with in this document, th
30、e plant designer should adopt the following principles: a) in water inflows intakes, stay within moderate velocities which allow gradual acceleration: examples of such velocities are those of the order of 0,3 m/s in the approach channel, 0,5 m/s in the strainer, 1,5 m/s in the bellmouth or tapered s
31、uction, and 4 m/s in the suction pipe; b) avoid excessively large chambers and dead zones which generate overall swirl in the flow and vortices as well as the deposition of solids if the water contains substances in suspension; c) prevent separation by avoiding sudden widening and excessively diverg
32、ent angles by preferring shaped forms for pillars, low walls, bellmouth or tapered suction, etc; d) avoid sudden changes in direction caused, for instance, by lateral feed and excessively sloping falls; e) eliminate any obstacle which might interfere with flow over a sufficient distance (of the orde
33、r of 10 times the diameter D at the entrance to the bellmouth or tapered suction) before the suction pipe; f) avoid any asymmetry in the mode of operation as well as in the design of structures; g) at the entrance to the suction pipe, ensure an adequate submergence for the minimum working level and
34、increase the submergence recommended below in this standard significantly if flow conditions are mediocre; h) if a chamber is fed with water by an overflow, ensure that the later does not entrain air and provide a baffle device. PD CEN/TR 13930:2009CEN/TR 13930:2009 (E) 7 It is far preferable to des
35、ign a plant which is intrinsically problem-free from the outset rather than to rely on baffles or anti-vortex accessories which are often only a palliative offering efficiency which is difficult to predict. In difficult cases and if the importance of the plant justifies it, it is recommended to use
36、a reduced model to check whether there is any need to improve the arrangements made. 3 Plant with vertical suction inlet 3.1 General arrangements In these configurations the presence of a bellmouth is necessary but alternatively, the bellmouth may be replaced by a tapered suction. Installations with
37、 a vertical suction are shown diagrammatically in Figures 2 and 3. a) The pump design may be: axial flow without exceeding the outside diameter of the bellmouth or tapered suction greatest diameter; centrifugal or mixed flow with bellmouth possibly wider than diameter of the bellmouth or tapered suc
38、tion greatest diameter. b) The position of the pump on the piping can be: horizontal or vertical; immersed or not immersed. Figure 2 Vertical suction inlet with bellmouth - Normal configuration PD CEN/TR 13930:2009CEN/TR 13930:2009 (E) 8 3a) Centrifugal impeller a)a) The number of stages is stated f
39、or information only 3b) Mixed-flow impeller a)a) The number of stages is stated for information only 3c) Axial flow impeller a)a) The number of stages is stated for information only 3d) Non-immersed horizontal pump 3e) Non immersed vertical pump 3f) Non immersed vertical pump 3g) Immersed vertical p
40、ump Figure 3 Vertical suction inlet with bellmouth (or with tapered suction) - Example of possible configurations PD CEN/TR 13930:2009CEN/TR 13930:2009 (E) 9 3.2 Diameter (D) at the entrance of the bellmouth or the tapered suction Figure 4 shows typical profile of bellmouth. Figure 4 Bellmouth The d
41、iameter D at the entrance to the bellmouth is a result of the bellmouth profile, which is generally a quarter ellipse of which the short and long axes have the values 2a and 2b respectively. If Dois the diameter of the piping at the entrance to the impeller of the pump, the value of D is generally b
42、etween 1,4 Do and 1,8 Doinclusive, the most common values are between 1,5 Doand 1,6 Do inclusive. It is this value which is used as a reference for the recommendations given in sub-clause 3.3 and so on. As an alternative of a suction by bellmouth, Figure 5 illustrates typical profile of tapered suct
43、ion. Figure 5 Alternative with tapered suction PD CEN/TR 13930:2009CEN/TR 13930:2009 (E) 10 3.3 Distance (C) between the bellmouth or the tapered suction inlet and floor Figure 6 indicates the recommended dimensions between suction inlet and the floor, in the case of a bellmouth. Figure 6 Distance b
44、etween the bellmouth and the floor The distance (C) between the suction inlet and the floor should be between 0,25 and 0,5 times the diameter (D) at the entrance to the bellmouth; the most common values are between 0,4 and 0,5 D inclusive. NOTE In the case of an intake on a natural floor (river, pon
45、d, sea, etc.) where there is always a risk of filling with sand, silting up or changing water levels, the distance (C) should be increased. Its value should be specified jointly with the pump manufacturer. As an alternative of bellmouth suction, the case of tapered suction inlet is illustrated by Fi
46、gure 7. Figure 7 Distance between the tapered suction inlet and the floor PD CEN/TR 13930:2009CEN/TR 13930:2009 (E) 11 3.4 Distances between suction inlet axis and walls Figure 8 indicates the dimensions between suction inlet axis and walls. Key 1 Rear wall 2 Water inflow Figure 8 Distance between s
47、uction inlet axis and walls 3.4.1 Distance (L) between suction inlet axis and side walls The recommended dimension (L) is 1 D. 3.4.2 Distance (E) between suction inlet axis and rear wall The recommended dimension (E) is 0,75 D. NOTE If cloudy or very cloudy water is sucked in, consult the pump manuf
48、acturer before specifying dimensions (L) and (E). In fact, it is necessary to take into account the risks of the pump feed being disturbed if deposits form (see note to sub-clause 2.1). 3.5 Submergence (S) 3.5.1 Conditions to be satisfied for the determination of submergence Figure 9 shows a typical
49、 submergence. Key S = 1 D to 1,5 D Figure 9 Submergence PD CEN/TR 13930:2009CEN/TR 13930:2009 (E) 12 The submergence value (S) should satisfy two conditions: a) the NPSH available should exceed the NPSH required at the maximum flow rate during use by a sufficient margin. In particular, this margin should make allowance for the air content of the water; b) the maximum submergen
