Building a metering pump

[Russ]

I think my project for this year will be the addition of a metering pump.  I am using a constant level tank now, but would like the more precise control of a metering pump.  I also like the idea of filtering before the pump, something that you cant do with the gravity feed of the constant level tank.

In the research I have done so far, it looks like the commercial built and home built units use a Suntec A2RA-7710 pump and some sort of 90VDC motor that can be controlled by a variable speed controller to adjust the RPM which affects the flow of the pump.

The motors I have seen mentioned are either Dayton or Bodine brand gear motors.  I think there are different controllers, but the one I seen mentioned was a Dart brand.

I am a little unsure of the RPM the motor needs to be.  The specs of the 7710 pump say .40GPH at 135RPM and a max of 2.5GPH at 3450RPM.  Tha'ts a pretty wide RPM range.

Does anyone have any suggestions as to where to start with a motor?

Doug, if you see this, do you have more specifics on what your motor and controller setup are?

Thanks for the help!

[doug]

Russ,

 I beleive my pump turns at 70 to 80 rpms. The motor turns faster, it is belt driven and gear to turn my pump slower.

doug

[Russ]

Hmm, thats a little slower than I was thinking.  A 500RPM motor might not even slow down that slow.

I have heard of some people using stepper motors.  I don't have any experience with them, but it sounds like maybe that would be an option as well.

[doug]

Russ,

I was going to build my own metering pump, then I found this one on ebay http://www.ebay.com/itm/Shenandoah-90-Volt-Variable-Speed-Meter-Pump-Assembly-/330647270883?pt=Motors_Automotive_Tools&hash=item4cfc1cf5e3#ht_2943wt_917 . It was cheaper buying this than building one myself.

doug


Russ: Added pictures from ebay listing for reference in case the auction is no longer available.

[Russ]

I moved your post to this topic.  Thanks for the link.  They have some nice pictures of what is going on inside that box.  That price does make me wonder if I can do it for any less.  I am still putting things together to see what I can do.

You mentioned your pump turning 70 to 80 RPM.  Is that the RPM of the pump, or the motor?  I see the pulley is quite large on the pump.  I suspect this to keep the RPMs down.

[doug]

Russ,

The 70 to 80 is pump rpm.

One of best thing I like about a metering pump is peace of mind that the float valve won't stick open and create a big mess.

This set up has worked good for me. The speed controller took a little getting used to.

To preset the amount of oil speed I needed I ran it into a measuring cup and timed it for the amount I wanted.

I tried sending you a PM the other day.

doug

[Russ]

Thanks Doug, I did get the PM.  Appreciate it.  Just didnt have anything specific for questions at the time.

What GPH is your pump at normally?

I dont even know what I am running.  I was thinking around 1GPH.

[doug]

Well if I did my math correct the amount of oil used and time the burner ran it's using 3.11 gph. I was trying to get more heat out of the boiler last year.

[doug]

Russ,


 This is the information from altfuelfurnace that I was using for a metering pump.


1. Bodine 500 rpm dc motor #24a4bepm-3f.

2. Suntec A2RA-7710 waste oil pump.

3. Bodine 810 controller .

doug

[Russ]

I found some of that info as well, but being the thrift shopper I am, I continued looking for cheaper solutions.  The post that caught my attention was this one:

i use an oriental electric motor #31k15gnaul with gearhead #3gn6ka speed control is an eso1 check out the oriental electric motor web site. this is an ac induction motor, all over ebay and not too expensive new

Oriental has many different motors that appear to be commonly used for automation equipment, packaging machinery, etc...

They have constant speed motors, but also have speed control motors.  The model listed in the quote above is pretty common on ebay, but it was the 31KR15 that I was interested in.  The "R" in the model number designates it's a speed control motor.  The beauty of these motors is not only the speed control (90-1600 RPM), but the gearheads you can attach to them.  The model of gearhead above is a 6:1 ratio head, so it would slow the motor down to 15-266RPM.  Directly coupled to a 7710 pump should give enough variation in RPM to suit quite a range of flow.

The ES01 control can be had out on ebay for around $50.

In searching around ebay I found a motor/gearhead/controller combo for $84 shipped.  Its not the 31KR15, but it has similar specs.  It is a US315-401U2 motor with a 3GN18SA gearhead and a USP315-1U2 speed controller.  All brand new in the box.  The auction said it was from the Solyndra plant that went bankrupt.  I dont think they really knew what they had.

The gearhead is a 18:1 ratio, so I hope I can get enough RPM's.  That should allow for 5-89 RPM.  If thats not enough, I can just buy a different gearhead.

Now its off to order a Suntec A2RA-7710.  I hope this all works!

[doug]

Russ,

Looking forward to seeing it in action.

Still thinking the Shenandoah metering pump will be cheaper. Beside the dc motor, controller and Sunteck pump it also came with a suction filter, vacuum gauge, pressure relief valve, pressure gauge, check valve and with a frame and cover.

doug

[Russ]

Yea, it should be a good learning experience.

You did get a lot of stuff with the complete setup.

I'm comitted now.  Pump & motor ordered. 

The pressure relief is for if the nozzle plugs?  Where does the relief go?  Is there a hose that feeds back to the tank so it doesnt make a mess on the floor?

[doug]

Nothing like the experience when you build your own.
The unit was assemble together parts memtioned in reply #10. All I had to do was wire the controller to the motor and electrical supply.
The relief valve does go on the burner side of the meter pump. On mine, I plumbed the relief side of the valve back in the supply line from the tank. After the metering pump is the check valve then the pressure relief valve.
Being the thrift shopper that you are you'll keep the cost down.

[Russ]

All of the parts have arrived.  I still need some various fittings, but should be able to get them locally.

Here is the motor, controller and pump:
$84 shipped - ebay.

[Russ]

And the pump: $85 - Pex Supply
Vacuum gauge: $11 - ebay
Pressure gauge: $9 - ebay
LOVEJOY 68514410207 5/16" coupler for pump
LOVEJOY 68514410208 3/8" coupler for motor
LOVEJOY 68514410194 Buna N spider - ebay $12 for all