N'Appuyez Pas Sur Le Bouton Rouge Index du Forum
S’enregistrerRechercherFAQMembresGroupesConnexion
Sponsor an event and assemble lists

 
Répondre au sujet    N'Appuyez Pas Sur Le Bouton Rouge Index du Forum » Association "N'Appuyez Pas Sur Le Bouton Rouge" » Vie de l'association Sujet précédent
Sujet suivant
Sponsor an event and assemble lists
Auteur Message
missdior


Hors ligne

Inscrit le: 21 Oct 2017
Messages: 61

Message Sponsor an event and assemble lists Répondre en citant
PublicitéSupprimer les publicités ?
There are two types of fan noise problems — those that we anticipate from our sound ratings and those emanating from some abnormal condition in the fan. Some of the more common sources of abnormal or unanticipated noise are:

1) Fan wheel unbalance.
2) Resonance of fan or attached components.
3) Rotating components rubbing on stationary parts.
4) Failing Leandro Castan AS Roma Jersey , misaligned, or contaminated bearings (on the fan or on the motor).
5) Air leakage. This can allow sound leakage and also generate a whistle-type noise.
6) Belts slipping.
7) Coupling misalignment.
8) Motor noise, especially with improper power supply. Inverter drives may increase motor noise at certain speeds.
9) Air turbulence.
10) Operation in surge.
11) Loose components.
12) High velocity air blowing over fixed components which are not part of the fan.

The phenomena of both sound and vibration are very similar and related. The term “sound” is used for air or other gas while “vibration” is used for a similar disturbance of motion in a solid. The sound pressure disturbance impacting on a solid can impart a vibration while the vibration of a solid can result in sound. Some prefer to call the concept of vibration which results in sound “structure borne noise.”

The other class of noise problems are those we have anticipated because of normal fan sound ratings. Some cures for these problems are:

- Select a different fan. Computerized selection routines allow us to examine many fan types looking for the quietest. Use a custom fan design, if required.
- Relocate the fan to where sound is not a problem.
- Vibration isolation and flexible connectors on the inlet and discharge will reduce structure-borne noise.
- Insulate or acoustically enclose the fan housing if housing radiated noise is a problem.
- Add silencers or duct lining to inlet and or discharge to reduce sound in these directions. However Kostas Manolas AS Roma Jersey , a silencer on the outlet does not reduce the housing radiated noise or inlet noise; and an inlet silencer does not affect the housing radiated andor outlet noise.
- Look for ways to reduce system resistance since sound output is proportional to fan static pressure.

One final tip which can help to avoid noise problems is to select lower RPM fans. Fans exceeding 3000 RPM are much more likely to tune in to an attached structure resulting in structure borne noise. Structure borne noise easily propagates an entire system and can become a problem at many locations. Also, people tend to become more annoyed with higher frequencies than with lower, increasing the likelihood of a noise problem.

Recently, several changes are developing in the technology of fan noise. Some of these are:

1. The latest codes define testing for fan inlet noise Kevin Strootman AS Roma Jersey , fan outlet noise, and noise radiating from the housing (or casing). The inlet noise can no longer be assumed to apply to the outlet and vice-versa.
2. A new test code which uses sound intensity is near adaption. In theory, integrating a series of measured sound intensities over an enclosed area yields the sound power directly.
3. Sound criteria is playing an ever more important role in the selection process. Many fans are insulated for sound or use other sound reduction apparatus.
4. Active noise cancellation continues to be difficult to apply to most fan installations. If it ever proves practical, this technique can cancel fan noise by adding a second pressure wave out of phase with the original.
5. Many more fan specifications are requiring AMCA sound certification. Certified sound ratings mean that AMCA has verified that the ratings are generated in accordance with the codes and that at least one sample has been tested in the AMCA Laboratory to verify the ratings.

For additional information please refer to http:www.tenderallventilatorindex

Oleg Tchetchel
Process air systems engineer
nisco@globalserve.net
Tenderall Fan Co.
http:www.tenderallcontactindex
http:www.tenderallahuindex It will be important to focus on designing the best possible business cards for your company Juan Jesus AS Roma Jersey , because they will be the first impression that many people will get when you hand them out. You will definitely want to find the right place to get your business cards printed up at, but it will also be necessary to focus on the actual design and layout of them. In order to make your business cards as effective as possible at bringing in new customers, it will be crucial to consider what they are going to look like.

One of the more common mistakes which you will want to avoid when it comes to business card design is overly cluttering yours with too much information or graphics. Make sure that you include basic details such as the name of your business as well as contact information and perhaps a tagline. When it comes to business card design, simple is the way to go. Although you will want to make these cards look nice and get people interested in what you have to offer Juan Iturbe AS Roma Jersey , it will be important to resist the urge to cram too much into such a small space.

Another thing which you will need to do is to list the web address of your business on the cards you have made up, so people will be able to visit your site and learn more about what you have to offer. It will also be necessary to make certain that you keep all of the information that is on your business cards up to date, because you will want the people who receive them to be able to contact you easily.

Whatever you do, make sure to get your business cards printed up professionally. Most people are instantly turned off when they receive cards which are made with flimsy low-quality paper and ink Hector Moreno AS Roma Jersey , so you will need to take the time . Cheap NBA Jerseys   Cheap Jerseys   Cheap Jerseys From China   Cheap Jerseys   Wholesale Jerseys   Wholesale Jerseys From China   Wholesale Hockey Jerseys   Cheap Nike NFL Jerseys   Wholesale Jerseys China   Wholesale Jerseys China 


Mar 7 Nov 2017 - 08:05
Contenu Sponsorisé






Message Sponsor an event and assemble lists

Aujourd’hui à 05:28
Montrer les messages depuis:    
Répondre au sujet    N'Appuyez Pas Sur Le Bouton Rouge Index du Forum » Association "N'Appuyez Pas Sur Le Bouton Rouge" » Vie de l'association Toutes les heures sont au format GMT + 2 Heures
Page 1 sur 1

 
Sauter vers: 

Index | créer un forum gratuit | Forum gratuit d’entraide | Annuaire des forums gratuits | Signaler une violation | Conditions générales d'utilisation
Powered by phpBB © 2001, 2005 phpBB Group
Design by Freestyle XL / Music Lyrics.Traduction par : phpBB-fr.com