Flow Rates for Solar Pumps

[periolus]

Just out of interest, I was wondering what the flow rates would be for liquid coming through 15mm and 22mm pipe, assuming there is a good quantity of liquid to provide decent pressure? The reason for asking is to help me determine the model of pump to get, as Solar Pumps (20/20 model) come in 6, 8 and 11 litre/min setups.

I am keen on the Solar 20/20 and wondered if anyone with the above models could let me know what flow rates they end up with, and how to maximise it using any plumbing wizardry!

 

[pjbiker]

I had a solar pump that I think claimed a 7l/min flow rate. I think this was reduced somewhat (maybe 1/2) when I pumped up about 1.5m via 15mm copper. I reckon the height had a greater effect than the pipe diameter. Basically, I'd go for 15mm as it won't make much difference for the cost. You must either regulate the power supply or use a balance valve to prevent overloading the pump when throttled, (I didn't, and did ). Now use a Totton 240V pump.

 

[periolus]

Hi!

That seems a shame - it's supposed to be able to support a 2.3m head at full flow rate. I would be pulling up about 1m at the most, so maybe that would be better. I will chat to Wendy1971 some more too.

Cheers for the response!

Counting the days to Christmas now :

 

[Mark1964]

we have one and the company owner said you need this one

this one

 

[Staz]

I've just purchased the 14watt version that's supposed to pump 11 litres per minute and have a 5 metre head. I should get the chance to test it the weekend provided my power supply arrives in time.

 

[periolus]

we have one and the company owner said you need this one

this one

That's the one I'm keen on, but didn't know whether to get the 6,8, or 14 watt version, as I didn't know what the likely maximum rate of flow out of a 15mm ball valve was. Does the pump pull the fluid faster from a vessel fitted with a ball valve, or do you have to match the output to what it is given by the natural gravity-feed from the vessel?

 

[pjbiker]

we have one and the company owner said you need this one

this one

That's the one I'm keen on, but didn't know whether to get the 6,8, or 14 watt version, as I didn't know what the likely maximum rate of flow out of a 15mm ball valve was. Does the pump pull the fluid faster from a vessel fitted with a ball valve, or do you have to match the output to what it is given by the natural gravity-feed from the vessel?

Not sure I fully understand your question but pump works best it the output is throttled by a valve, rather than the input. Also, they will not pump air, so make sure you have a way of 'priming' the system to allow air out. If you can make the pump the lowes point in the system this will be easier.

 

[Mark1964]

thats what we do put the pump lower than the vessel your pumping from the flow is adjustable by using the power output 3v slow flow and 12v fast flow it will pump over 6 litres a minute when we tested it on 12 v

 

[periolus]

pjbiker - sorry, I wasn't very clear. What I was trying to say was that with a 15mm valve fully open there is going to be a maximum rate at which fluid will flow out of it naturally (fed by gravity only). What I wondered was - will a pump be able to suck the fluid through its input at a higher rate than that, forcing fluid through the valve at a higher speed than if the pump wasn't being used.

I see the point about having another valve to act as a throttle for the output. I will have to factor that into the build!

 

[pjbiker]

What I wondered was - will a pump be able to suck the fluid through its input at a higher rate than that, forcing fluid through the valve at a higher speed than if the pump wasn't being used.

Yes it will.

I see the point about having another valve to act as a throttle for the output. I will have to factor that into the build!

As mark says, you can control flow rate using a voltage adjuster but I'd still say it's worth having some kind of valve on the output

 

[periolus]

That's the answer I was looking for! Just out of interest, is it a really bad idea to use a pump to get from boiler to FV? I know there is a serious issue with post-boil sanitisation, but can it be done easily?

 

[pjbiker]

That's the answer I was looking for! Just out of interest, is it a really bad idea to use a pump to get from boiler to FV? I know there is a serious issue with post-boil sanitisation, but can it be done easily?

No, providing you sanitise. Rinsing then pumping boiling hot wort through everything for a few minutes should be sufficient. I pump through my chiller into FV. I usually give the chiller a good flush with hot washing soda or oxy bleach before rinsing and sanitising.

 

[Mark1964]

take note though if your pumping from boiler to fv let the wort fall in to your fv from a bit of a height as the oxygenation of the wort will help the yeast get going