Building scrubber

[Emryst]

Long post so apologies for that.

I saw this design from one of the fellow members here, you prolly saw the post. My question maybe simple or not I am not sure as I have zero idea in the math to calculate the flow rate needed or maybe even whats to much. My plan is going at it with test runs with basic water when I have it completed. I don't have a fan of any type so I have to buy one. I'm working in my shed that I have retro fitted with plywood walls and put winindow a/c as i had been using it as a work shop of sorts.
Anyway to get to my question this set up would this fan have too much power in flow rate or not enough? I don't want to go wasting money on fans or anything only to have find out it's too much and should have got another one.

As far as the plans go I'm gonna follow it pretty close to plan. Tho I'm having some concerns as to how to solve the air tight system at the bucket with the pipes and hose from pump but not my biggest issue.

I'm sure I have other concerns but at the moment this is my first as I'm wanting to make purchase so I can get building it.

 

[Emryst]

Long post so apologies for that.

I saw this design from one of the fellow members here, you prolly saw the post. My question maybe simple or not I am not sure as I have zero idea in the math to calculate the flow rate needed or maybe even whats to much. My plan is going at it with test runs with basic water when I have it completed. I don't have a fan of any type so I have to buy one. I'm working in my shed that I have retro fitted with plywood walls and put winindow a/c as i had been using it as a work shop of sorts.
Anyway to get to my question this set up would this fan have too much power in flow rate or not enough? I don't want to go wasting money on fans or anything only to have find out it's too much and should have got another one.

As far as the plans go I'm gonna follow it pretty close to plan. Tho I'm having some concerns as to how to solve the air tight system at the bucket with the pipes and hose from pump but not my biggest issue.

I'm sure I have other concerns but at the moment this is my first as I'm wanting to make purchase so I can get building it.

Sorry I forgot to mention in post the fans specs state 700cfm as noted in the Pic attached. It's like 38 bucks from amazon.

 

[Yggdrasil]

Sorry I forgot to mention in post the fans specs state 700cfm as noted in the Pic attached. It's like 38 bucks from amazon.

There are many posts regarding this and one thread that has been going on just now is this one:
https://goldrefiningforum.com/threa...s-and-fume-scrubbers-_hood_.34601/post-372857

Please spend some time searching before you post new threads.

 

[4metals]

The fan is way too large. The fume needs to stay in contact with the solution pumping over the packing for around 8 seconds. Calculating the area of the packing in the design and the CFM listed for the fan, it is 152 times more flow than required. At that rate the exposure of the fumes to the scrubbing chemicals, the system will have little to no effect.

Area of packing = .610 cubic feet
to get the flow time correct multiply by 7.5 (the number of 8 second increments in a minute) This translates into 4.579 cubic feet effective area for proper fume exposure. making 700 CFM 152 times too big.

edit to add calculation.

 

[Emryst]

The fan is way too large. The fume needs to stay in contact with the solution pumping over the packing for around 8 seconds. Calculating the area of the packing in the design and the CFM listed for the fan, it is 152 times more flow than required. At that rate the exposure of the fumes to the scrubbing chemicals, the system will have little to no effect.

Area of packing = .610 cubic feet
to get the flow time correct multiply by 7.5 (the number of 8 second increments in a minute) This translates into 4.579 cubic feet effective area for proper fume exposure. making 700 CFM 152 times too big.

edit to add calculation.

Thanks so much. I don't know the math on how to calculate the flow rate to keep the games in solution long enough but with all my reading on this forum and elsewhere I had a feeling it was to much flow. I guess my thinking is always bigger is better and more power is the best. Lol not for this application tho.

 

[Emryst]

There are many posts regarding this and one thread that has been going on just now is this one:
https://goldrefiningforum.com/threa...s-and-fume-scrubbers-_hood_.34601/post-372857

Please spend some time searching before you post new threads.

My bad I saw equipment thread and naturally thought the scrubber fell within that requirement. I mean shouldn't we all be using a scrubber of some sort for our equipment. Is there a way I can move this post or do I have to copy paste it a an new add to the scrubber thread?

 

[Emryst]

The fan is way too large. The fume needs to stay in contact with the solution pumping over the packing for around 8 seconds. Calculating the area of the packing in the design and the CFM listed for the fan, it is 152 times more flow than required. At that rate the exposure of the fumes to the scrubbing chemicals, the system will have little to no effect.

Area of packing = .610 cubic feet
to get the flow time correct multiply by 7.5 (the number of 8 second increments in a minute) This translates into 4.579 cubic feet effective area for proper fume exposure. making 700 CFM 152 times too big.

edit to add calculation.

Question would too low flow rate make it so there is no pull of air at the intake on the hood but rather just suck the air from the tub of solution making it implode?
With that concern is there a flow rate of solution I should be shooting for with the pump. I picked a 400gph with a 6 ft upward lift capacity. But in fairness it's a pump for a pond not a small aquarium. Sadly I already bought this so if I'm over shooting again with too much power I'll have to suck that one up as on the learning curve. My thinking on the pump was it being made of something that will last in 2M NaOH solution so I'm not just throwing good money after bad when it fails in a month. And to have enough power to project the solution upward the 5 ft or so to the 4" pvc pipes and keep everything lubricated for good contain for scrubbing.

 

[Emryst]

The fan is way too large. The fume needs to stay in contact with the solution pumping over the packing for around 8 seconds. Calculating the area of the packing in the design and the CFM listed for the fan, it is 152 times more flow than required. At that rate the exposure of the fumes to the scrubbing chemicals, the system will have little to no effect.

Area of packing = .610 cubic feet
to get the flow time correct multiply by 7.5 (the number of 8 second increments in a minute) This translates into 4.579 cubic feet effective area for proper fume exposure. making 700 CFM 152 times too big.

edit to add calculation.

Question would too low flow rate make it so there is no pull of air at the intake on the hood but rather just suck the air from the tub of solution making it implode?
With that concern is there a flow rate of solution I should be shooting for with the pump. I picked a 400gph with a 6 ft upward lift capacity. But in fairness it's a pump for a pond not a small aquarium. Sadly I already bought this so if I'm over shooting again with too much power I'll have to suck that one up as on the learning curve. My thinking on the pump was it being made of something that will last in 2M NaOH solution so I'm not just throwing good money after bad when it fails in a month. And to have enough power to project the solution upward the 5 ft or so to the 4" pvc pipes and keep everything lubricated
I guess I'm also concerned that if the water flow is to high thru the packing it could back up and cause a back up of gas in the hood.