Tagged With "housing"

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Raw Mill Bag House Fan Vibration Critical Issue

Garry Kristen ·
Hi there, I would like to share the vibration trend of our Raw mill Bag House Fan. the fan has been running with abnormal vibration from 4.5 to 7 mm/sec on Horizontal point NDE bearing HH for last 6 months. the main problem is coating and fine dust that is coming from the bag house chambers due to worn and useless bags. this coating build up on fan impeller rapidly and results the fan is unbalance twice in a week. Then we have to stop the fan for a hour and clean the coating by air pressure...
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Equipment protection for storage

Alvin MC ·
Im looking for best practices when it comes to protecting storage equipment like pumps and gearboxes for an extended period of time? Do you store equipment with just vaprotech or cortec for preservation? How about storing them with mineral oil and preservative? If so, what should be the oil level? fill the whole housing? Thanks
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Vibration at houses near to a Pumping Station

Alvaro Loayza ·
Good morning, We have a problem with people complaining about vibration due to our Waste Water Treatment Plant operation. I will explain this briefly: We built a WWTP to treat and clean waste water for the city. Part of this water goes to our concentrator plant. So we have a pumping station in the suburbs and a 48 inch diameter pipe that sends the waste wáter from the city collector to the WWTP. I know that this is a buried but not insulated pipe. The problem is that since this plant started...
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tilting pad design

Hesam267 ·
Hi friends As we know there are instructions and limits in tilting pad journal bearing. I know it's for Babbitt side (or side of rotating shaft) but I don't know anything about bottom side the side lead on cover or housing bearing. Do you know any information about it's design law's.
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High gearbox housing vibration

Santosh Shankarappa ·
Hi, GB details: Double stage single helical for cooling water pump application. Power: 1450kW; Input/Output speed: 5900/590 (10:1 ratio) Recently I was shared a site vibration data of a high speed gearbox , The housing vibrations measurement details are attached; From the spectrum data , the dominant frequency is at 53,000 cpm which is close to 9X of Input pinion shaft rpm. The vibrations are found dominant at pinion shaft non drive end (28 mm/sec) Kindly share your views. Santosh S
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Re: Vibration at houses near to a Pumping Station

Beatnik ·
It looks like resonance, I suppose those pumps are variable speed?? You need to record this event with an analyser to find the frequency and see if it fits with the vann pass frequency of the pumps at this moment. You could go in the field and have them vary the speed in all the operating range and record the vibration to see how much the amplitude vary. If you can recreate the phenomenon this way you could also find which segment of the pipe vibrate the most and learn where to act. If you...
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Re: Vibration at houses near to a Pumping Station

Shurafa ·
In large projects, pre-construction survey is usually conducted to establish a baseline for key parameters that could lead to legal complications (after the plant is put in service). For example, vibration, noise, air quality and seawater marine parameters (temp, PH etc.) are taken through a very specific and reproducable procedure. In your case, you may need to check if such a survey was conducted or not. I would also recommend to take measurements to establish/falsify the complaint about...
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Re: Vibration at houses near to a Pumping Station

Alvaro Loayza ·
Dear Ali Al-Shurafa, Thank you for your response, We have started to make measurements with advance transient in our CSI2140.Also, we are taking triaxial vibration overall value in G's pk-pk according to ISO2632-2. We expect to get some usefull information, specially from transient surveys. ¿Could hydraulic forces or pipe resonance be the source of this problem? Load is variable due to collector tank level and transient events could generate this fluctuation. Please let me know if you have...
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Re: Vibration at houses near to a Pumping Station

Callum S ·
Have you determined the frequency of the vibration?
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Re: Vibration at houses near to a Pumping Station

Alvaro Loayza ·
We made a measurement perpendicular to a house wall in second floor. When we put our backs to the house wall we really noticed that complains were true because vibration is continuous. I think 0.8 mm/s at 525 CPM could be structure vibration due to a natural frequency But, what is exciting it? Greetings
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Re: Vibration at houses near to a Pumping Station

Shurafa ·
If I were you, I will take many measurements witnessed by the house owners focusing on the locations of most concerns. The readings I would report and use the as baseline for the severity to close the case later. I would also collect different (many) measurements to diagnose the problem. With respect to 0.8 mm/sec, it is high. With respect to the frequency 525 cpm, I doubt it is a structural resonance of the house walls excited by a force far a way but I could be wrong. What material is the...
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Re: Vibration at houses near to a Pumping Station

Dan Timberlake ·
What is the construction of the walls? Acoustic phenomena can easily excite wall and other panel vibration over long distances. If, by chance, the "sound" frequency is a match for the panel's lateral resonance then the panel vibration can be quite high. 2X4 stud wall construction here in the US often has resonant frequencies in the low audible range. When a Honda Civic drives by and the owner has his 1000 Watt sound system cranked, the bass thump gets right into my house even if the doors...
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Re: Vibration at houses near to a Pumping Station

Dan Timberlake ·
" .......... 0.8 mm/s at 525 CPM ....... But, what is exciting it?" You are the only one in a position to answer that. Measurement on the facility walls and equipment, and getting familiar with the nature of the equipment will be required.
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Re: Vibration at houses near to a Pumping Station

Walt Strong ·
"But, what is exciting it?" The first items on your list should be pump speed and number of impeller vanes. Can you find any machine or plant structure with the same frequency to at least have the possibility that frequency at neighbor is the same as at the plant? Is the vibration noticed when sitting in chair, standing on floor, or laying on bed? Do windows or loose items rattle when vibration is present? Is audible sound part of the annoyance? If there are considerable complaints and there...
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Re: Vibration at houses near to a Pumping Station

Alvaro Loayza ·
Hello to everybody, Thanks for every response. Well we are actually making lots of measurements.We have surveys with 12 hours of transient waveform in every complainer house. Measurements are made putting accelerometer vertical over a 8' x 5' x 2'steel plate. (I mean vertical is perpendicular to floor). We are also making 2 hour overall waveform value in some places expecting to catch peak events. We have not found strong conclusions. I've noticed, talking about amplitudes, that vibration is...
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Re: Vibration at houses near to a Pumping Station

Shurafa ·
Very good comments/questions have been given already. Can you let us know these basics? 1- The speed(s) of the pumps. Is the speed constant? I assume there is no gear or VFD. 2- No of vanes and stages of each pump. 3- Can the pumps be shutdown for a short period of time? 4- Is 520 cpm common in all/most readings collected from those houses? Any common signs? 5- Are there any underground piping from the station running under or close by these houses? 6- How long the peak vibration levels...
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Re: Vibration at houses near to a Pumping Station

John from PA ·
You can't correlate any vibration measurements taken on an 8 x 5 x 2 steel plate to a house wall, and I assume you mean the plate is 2 inches thick, not 2 feet thick.
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Re: Vibration at houses near to a Pumping Station

Callum S ·
I would assume, that since the pumping station is designed to serve the nearby affected homes in the suburbs that the homes and the pumping station would have to be directly connected with underground solid piping from the homes to the plant . If it is an older community the piping would be very thick wall as well not todays plastic or thin walled piping.
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Re: Vibration at houses near to a Pumping Station

Alvaro Loayza ·
Thanks for your replies. I will answer all your questions - There are 6 pumps running between 1550 to 1780 RPM. There are no gearboxes only VFD - These single stage centrifugal pumps impeller have 5 vanes each one of them - They can't be shut down but when equalization tank level is low there is only one pump working so this could be a way to have the other ones off. - I made this velocity vibration measurement only in one house perpendicular to the wall luckily when a high vibration event...
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Re: Vibration at houses near to a Pumping Station

Shurafa ·
The vibration recorded inside the house is 525 CPM = 525/1550 = 0.339 X pump speed or slightly above 1/3 X. Do you have this frequency in the station anywhere? Are you sure the frequency is accurate enough? Was this frequency clear in other points in the house (eg other rooms, same room but different wall, same wall but different height) from which you took this spectrum? Based on your feedback, you could detect high vibration only on one house anong a few you survived despite the long data...
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Re: Vibration at houses near to a Pumping Station

Ron Stiemsma ·
Do more than one pump run at a time. If so maybe two pumps running slightly different speeds are causing a low frequency beat or pulsation in the piping.
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Re: Vibration at houses near to a Pumping Station

Alvaro Loayza ·
Hello to everyone. I'm writing this post 50 days after your last reply and want to apologize for it. We have solved this big problem with ATA engineering help because they brought some new data acquisition modules and made data collection and analyzing it for us. Well, they found that high vibration came from EDS valve station. Actually the pipe that returns water from WWTP to the river had several issues with flow turbulence due to the high pressure and restriction in valves. They decided...
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Re: Equipment protection for storage

John from PA ·
API 686 Recommended Practices for Machinery Installation and Installation Design has a section covering preservation. It is very specific as to machine type; for example, what you might want to do relative to a centrifugal compressor might be significantly different than what you would do to a reciprocating compressor.
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Re: Raw Mill Bag House Fan Vibration Critical Issue

CM Inspector ·
Dear Rizwan , This is common in cement industries,Particularly in Preheater Fans due to high sulphur content and various other Process parameters. But in case of Raw mill Bag house it is the question of effectiveness of the fabric filters, first course of action would be through checking of the filter bags.second would be asking your process people to measure the dust loading and flow measurements to know whether any change happened. if both are ruled out , then if coating is the real issue...
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Re: tilting pad design

John from PA ·
Kingsbury makes a vast amount of material available online. I suggest you go to http://www.kingsbury.com/file_library.shtml and perhaps start with the first item ( http://www.kingsbury.com/pdf/universe_brochure.pdf )
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Re: High gearbox housing vibration

John from PA ·
Q1. What is the tooth combination? Q2. Fluid film or rolling element bearings? Q3. Is the casing a weldment or a casting? Q4. What is the exact transducer being used? Q5. I see 16 mm/sec 2 as your highest level acceleration. I could have done the conversion incorrectly (I'm working from a tablet) but in making the conversion to g's I get the following. In comparison to API 613, the levels you have measured seem low.
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Re: High gearbox housing vibration

Walt Strong ·
The spectrum document shows both acceleration (g) and velocity (mm/sec) plots. Point #4 12.7 g acceleration and 16.7 mm/sec velocity at cursors. The gear tooth mesh (51 to 53 kHz) appears to have modulation sidebands. Suggest more resolution to identify which shaft/gear may have a fault. Walt
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Re: High gearbox housing vibration

John from PA ·
I stand corrected, I quickly scanned the spectra for frequency and relied on the spreadsheet for amplitudes, which are only micron, mm/sec and mm/sec 2 My questions Q1 through Q4 remain to be answered. Are you certain this is a single helical? Is the ratio supposedly 10:1 exactly .
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Re: High gearbox housing vibration

Santosh Shankarappa ·
Q1. What is the tooth combination? AI: It is single helical double stage gearbox, Teeth count: I/P P/S: 26; Int P/S:32 & Int G/W:85; O/P G/W:99 Speed: Input shaft: 5900; Intermediate shaft: 1805 & Output shaft: 590 Q2. Fluid film or rolling element bearings? A2: It is hydrodynamic bearings Q3. Is the casing a weldment or a casting? A3: Fabricated casing with weldments Q4. What is the exact transducer being used A4: Accelerometer
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Re: High gearbox housing vibration

John from PA ·
Q4. What is the exact transducer being used By "exact" I had hoped to learn the make and model of the accelerometer. In addition it would be good to know how it is mounted, and where. Is it mounted on a relatively thin portion of the casing or the thick portion of the casing near the bearing. Any pictures of transducer when mounted?
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