Please save your self hours of aggravation by purchasing a pipeline pig to clean your delivery pipe.

Do not purchase hose for this service as it is not

worth the time or effort as you will develope pinhole leaks and loose many Hg. vacuum as vacuum energy is like electricity snd water very lazy and it will go anywhere if it can.

Keep it simple, dumb and stupid by using a

flexible pipeline cleaning pig.

All thay you will need to do is install a 4 inch pig launcher "Y" and a 4 inch pig reciever at the end of the pipe line in both directions to facilitate cleaning from end to end. besides that they don't squeal to much when they get blown out of the pipe :^).

Google (Pipeline Pigs) in parenthesis and you will be able to find a supplier that will help you very easily and quickly especially if you can use grooved pipe fittings -Victaulic brand- You will save money and time and you will not have bang on pipe or replace elbows either and not have to worry about pinhole leaks from erosion of metal in the elbows or energy loss from poor vacuum performance. You will not be disappointed.

I do not mean to be long winded but I hate to see effort and money wasted. Gibbsy took my advice about pipeline pigs and solved his problem.

I am not affiliated with any pipeline pig organisation etc.

lzaharis ■

Jake

While pigging is one approach, there is good history in using flexible hose which is anchored in place but not FIXED as to restrict any movement. The flexing of the hose will tend to release build up of material.

One supplier to contact for hose recommendations is Titan Industries. Check out www.titanindustries.com.

Another solution you may wish to consider is to use elbows which have removeable wear back plates. The plates can be removed at various time intervals and you then have an easy access to clean out build-ups. The elbows will be of the short radius design but since you only have (4), I wouldn't expect a significant affect on your conveying capacity. One such supplier is Delta-Ducon; Contact Matt DelPizzo. See www.deltaducon.com.

Good Luck

Regards ■

Mr. Hilbert, what about "actual gasket life" in regard to the elbows in question. since they are a compression gasket it leads me to think they would be a problem as well.

lzaharis ■

Dear Izaharis

The gaskets can easily be a sealant applied to the surface of the elbow and replaceable back section when assembled and cleaned and replaced when the elbows are cleaned out.

As an alternative, normal flat gaskets can also be used between the mating surfaces.

Remember, we are talking about a vacuum system here where all air flow is INTO the system. If gaskets become compromised in a vacuum system, it typically isn't a problem UNLESS sufficient air flow leaks in to create a pick-up velocity problem up- stream of the leak.

Regards ■

Dear Mr. Hilbert,

I was using the experiences of repairing and maintaining roof bolting machines used in hard rock mining which utilised a variety of piping for rock dust collection etc.

leon ■

Jake,

Build up in bends is mostly caused by low solids velocity unless the solids are such that they smear. Solids slow down as they enter and go around the bend. Difference between the air velocity and the solids velocity at the exit from the bend depends upon the solids' properties but it can vary from 10% to 30%. If your pick-up velocity is close to saltation, this reduction in solids' velocity when going through a bend will result in this build-up.

If this is the case, one simple solution is to increase the solids velocity by speeding-up your vacuum blower.

Regards,

Amrit Agarwal

Consulting Engineer

Pneumatic Conveying Consulting

Emailolypcc@aol.com

Ph and Fax: 304 346 5125 ■

Jake

Build up in bends due to low velocity normally is a recirculating type of action where a mass of material remains in the bend or slightly downstream and falls back if a vertical line follows a bend. When the conveying batch is over and the differential pressure across the conveying line drops, the velocity automatically increases and typically sweeps the bends clean. There are some cases if the velocity is so low that residual material will remain in the horizontal lines.

From your original description, material dropping out from low velocity typically wouldn't stratify on the pipe walls requiring "beating" to get it free.

Increasing your velocity can very often lead to reduction in conveying capacity so I would suggest caution in just speeding up the blower without first checking the existing velocity profile in the system and also, where on the vacuum blower performance curve you are operating so you don't exceed the available motor HP.

Regards ■

Dear Sir,

please note that your Problem Can be solved by using long radious Bends in The Conveying Line to over come the prblem.

Please do contact for it.

Saravana Kumar.P

manager Marketing & Service

91-80-25485362

09448273095

pcem@iqara.net ■

Jake,

There are two methods to solve your problem: one is prevention and the second is removal. I have given above the high velocity method for preventing the build-ups. This method is used if the higher velocity does not exceed the conveying blower pressure limit. If it does, the other technique is to inject additional conveying air at inlet of the bends using a properly sized sonic nozzle.

If the above method is not cost effective, a proven method for deposits removal is conveying of crushed ice through the conveying line.

Regards,

Amrit Agarwal

Consultant

Pneumatic Conveying Consulting

Emailolypcc@aol.com

Ph and Fax: 304 346 5125 ■