40m for brunt lime is not a problem. Standard tanker arrangement should unload it in 4” within an hour. Give details of your current tanker type,compressor and unloading procedure. What problems you are currently facing ? 6 bar compressor is not an option. ■

I am sure my friend Teus will give you sage advise on this as well;

What is the conditon of the burnt lime? is it damp?

What has changed recently, repairs, rebuilds, new hoses?

What has the surrounding ambient air temperature been? if it is hotter the system will

not perform as well due tot he air being less dense. Perhaps making deliveries at night will solve this problem for you?

If the system is in good condition you may be dealing with a

dense phase/ mass flow situation rather than a dilute phase transfer with your

burnt lime and need to restrict discharge prior to the airstream.

Not having seen your unit I must ask if the tanks are segregated with individual valves between tanks-

closing the tanks furthest away from the discharge end will be a simple fix for this as the blower will be

pulling the lime from the entire length of the drawdown piping if it is fully open from front to back.

Regarding your blower- when was the air filter changed last?

The air filter may have plugged and it may not be noticed

IF IT IS A TWO STAGE FILTER BOTH THE INNER AND OUT FILTER MUST BE CHANGED

AS THE INNER FILTER WILL PLUG BEFORE THE OUTER FILTER.

If an oil bath precleaner filter is used the sediment bowl needs to be cleaned and the oil needs to be dumped and replaced regularly.

Is the discharge muffler emmiting dust- the blower may be damaged.

How long has this blower been in service?

Have you checked the condition of the relief/ vacuum regulator valve?

It could be that the relief regulator may be bad and needs replacing

Have you checked the loading hatches and or gaskets of the tank?

can this unit be used for suction as well as pressure?

What about any check valves?

Even a little build up ruins the seal amd use of vacuum.

Do you have a milk house vacuum testing kit to check the blowers efficiency?

You cannot trust the guages provided with the system.

Have you checked the delivery pipe for any build up of dust? heat from friction will draw moisture.

The piping from the silo may have build up and it will cause youu delvery problems.

Is the silo automaticly vented with an elbow and screen or is it using a relief pressure hatch?

If the screen is plugged the air preessure will back up and be relieved by the regulator/relief valve.

Related to the question above what are the gaskets or pipe joints sealing surfaces condition?-thats a big one.

How old are the piping clamps? if they are loose they will leak reducing The HG.

If they are sprung they must be replaced.

Any dedicated swivels in the delivery piping?

As the system is under pressure it may have one or more pin hole leaks you may not be hearing during the transfer as well

I would see if i could by a 4 inch flexible pipeline pig that you could clean the delivery lines within the bulk unit piping=assuming

there under the trailer by sing the pull ring to pull the pig through and cleaning the lines if they have build up. the same pig could

be used for the silo with some rope and a fishing tape used for pulling wire= but look for the simple things first.

If the blower is a regenerative vane type the vanes may be worn and need replacing.

If its a Roots type Positive displacement lobe blower it may need a new blower.

Have you checked the oil level for the gears sets? How often do you grease the bearings?

look for the simple problems first and then go forward inch by inch.

Use some very soapy water to check for joint leaks, hatch leaks, hose leaks, piping leaks at the blower itself including the

end plates sealing surfaces/gaskets inlet piping at the air filter and the discharge pipe exiting the blower.

I hope it will be an easy find and easy fix for you.

Teus My aplogies if I missed something.

leon ■

Dear sebabu,

I hope that the 6 bar was not put on the tank on the truck. You might end up as “Breaking News”.

For answering your question, we need to know:

Particle size (distribution) of the quicklime

Compressor data: air displacement and maximum pressure.

Horizontal conveying length

Vertical conveying length

Number of bends.

Then it is possible to calculate the conveying capacity and compare that result with the actual performance. (Standard approach)

Have a nice day

Teus ■

Sebabu,

Suggest you read my article "Debottlenecking Pneumatic Conveying Systems" published in Chemical Enginering. This article can be used by you to investigate why you are having this problem. You can then select any of several methods described in the article.

Regards,

Amrit Agarwal

Consulting Engineer

Pneumatic Conveying Consulting

Charleston, WV, USA

Email: polypcc@aol.com ■