Increase production rate of Grit Blasting of steel plates

[Adarsh]

Hi SE forum!

I am new to this forum and I am completely new to Blasting plant systems. I am currently working on improving the production rate of a steel blasting plant in Singapore and I had a few questions regarding improving production rate while keeping quality at the same level. I appreaciate any help on this matter.

Currently the blasting plant in use is a very old plant that runs the conveyor belt at 1.1m/min. the Blasting quality achieved is a smoothness deviation of about 60-80 microns and what I am told is "Level 2 on the Blastmaster quality chart" for steel blasting. this level 2 rating is based on the requirement that the surface is smooth and there are still few marks which signal the areas that were infected with rust flakes. Level 2.5 requires that almost all the marks of rust are completely removed. (this normally requires repeated blasting).

Upon turning up the speed of the conveyor belt for a test plate, i noticed that with the increased speed, significantly higher portion of the rust marks were visibile on the surface but it was still as smooth as before.

My question is, does it matter that there are more rust marks visible? is this very important to a long shelf life for the steel?

and if it is important, then is there any other way i can improve the blasting and at the same time increase the production speed? (Like better abbrasive grits, or higher pressure on the grits)

Cheers to anyone who answers this!
Adarsh

[Gordon]

Hi Adarsh

to the Surface Engineering Forum.

My question is, does it matter that there are more rust marks visible? is this very important to a long shelf life for the steel?

I suppose that this depends really on what the steel is going to be used for and any post surface treatments.

and if it is important, then is there any other way i can improve the blasting and at the same time increase the production speed? (Like better abbrasive grits, or higher pressure on the grits)

Better abrasive grits and higher blasting pressure will have an effect, but really to increase production will really need you to increase volume of of grit being thrown at parts ie have two blasting nozzles rather than one.

[Adarsh]

Thanks Gordon!

I dont think the cost of a new Blasting nozzle, or another blasting machine itself will be very cost effective for us with regards to increasing production. I will be looking at the other suggestions you gave.

With regards to conveyor belt speed, is there a industry benchmark that we can hope to compete againts? Right now we blast about 30 9.144 m steel plates in one 10 hr shift. Is this a below par performance or is it ok?

Thanks,
Adarsh

[Gordon]

Hi Adarsh

With regards to conveyor belt speed, is there a industry benchmark that we can hope to compete againts? Right now we blast about 30 9.144 m steel plates in one 10 hr shift. Is this a below par performance or is it ok?

Can't really help with this one. But I would imagine you would need to talk in terms of surface area treated per unit time, while considering hardness and surface condition of steel and resultant finish obtained to make any comparison.

[djewell]

With regards to conveyor belt speed, is there a industry benchmark that we can hope to compete againts? Right now we blast about 30 9.144 m steel plates in one 10 hr shift. Is this a below par performance or is it ok?

Thanks,
Adarsh

How wide are your steel plates? How hard is the steel? Is it regular carbon steel or some hard alloy? How rusty are the plates before you start blasting them?