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Very small pump or equivilent for caustic chemicals — Parallax Forums

Very small pump or equivilent for caustic chemicals

ArchiverArchiver Posts: 46,084
edited 2003-06-16 12:26 in General Discussion
Thanks to invaluable assistance from Tracy Allen and others on this list, I
have successfully made a full fledged prototype of a pool chemistry controll
replete with 320x200 graphics LCD, trend log graphing (4000 sample history),
serial output, pushbuttons, the works. Its based around the AVR Mega32 now
(needed the memory and I/O) but the stamp and this list is what taught me
the majority of what I needed to learn. I'm just working on getting it off
the breadboard and onto a PCB at the moment.

As a stepping stone, I'm going back to an earlier design (no logging, no
clocks, just displayed numbers at a 4 line text LCD) as a tool for teaching
people how these controllers work. My BS2 will hopefully provide the brains
for it.

Anyway, I plan on using a 5 gallon bucket as to represent a swimming pool
and I'm looking for ideas on how to feed in sodium hypochlorite and muratic
acid. The amounts added will be very small and the solutions quite dilute. 1
oz should take between 5-10 minutes to add and the feed rate needs to be
variable. I need to simulate metering pumps (as used in real swimming pools)
to show the affects of mismatched pump speeds etc.

I've no experience with feeding these miniscule quantities other than using
an eyedropper... Any ideas? My only (half formed) thoughts so far is some
sort of miniature solenoid and gravity feed through a small plastic tube, or
a small pump (like the Earth measurements kit one) and using short pulses
spaced far apart.

Merci!

Meridian 59 is back! Sacred Haven - server 200
www.skotos.net
Original Message
From: "acatano2002" <acatano2002@y...>
To: <basicstamps@yahoogroups.com>
Sent: Tuesday, June 10, 2003 7:13 PM
Subject: [noparse][[/noparse]basicstamps] Play with DUALSHOCK 2


> For those interested in playing with the BS2P and the Sony
> DUALSHOCK 2 Controller, I created a small game.
> Please contact me and will send you a copy.
>
>
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Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-06-11 04:26
    Just don't forget about siphon action when you figure it out. Maybe a small
    single-stroke air pump forcing the chemicals out of a sealed container? Or
    one of the roller pumps like they use on medical stuff?

    Original Message

    > Thanks to invaluable assistance from Tracy Allen and others on this list,
    I
    > have successfully made a full fledged prototype of a pool chemistry
    controll
    > replete with 320x200 graphics LCD, trend log graphing (4000 sample
    history),
    > serial output, pushbuttons, the works. Its based around the AVR Mega32 now
    > (needed the memory and I/O) but the stamp and this list is what taught me
    > the majority of what I needed to learn. I'm just working on getting it off
    > the breadboard and onto a PCB at the moment.
    >
    > As a stepping stone, I'm going back to an earlier design (no logging, no
    > clocks, just displayed numbers at a 4 line text LCD) as a tool for
    teaching
    > people how these controllers work. My BS2 will hopefully provide the
    brains
    > for it.
    >
    > Anyway, I plan on using a 5 gallon bucket as to represent a swimming pool
    > and I'm looking for ideas on how to feed in sodium hypochlorite and
    muratic
    > acid. The amounts added will be very small and the solutions quite dilute.
    1
    > oz should take between 5-10 minutes to add and the feed rate needs to be
    > variable. I need to simulate metering pumps (as used in real swimming
    pools)
    > to show the affects of mismatched pump speeds etc.
    >
    > I've no experience with feeding these miniscule quantities other than
    using
    > an eyedropper... Any ideas? My only (half formed) thoughts so far is some
    > sort of miniature solenoid and gravity feed through a small plastic tube,
    or
    > a small pump (like the Earth measurements kit one) and using short pulses
    > spaced far apart.
  • ArchiverArchiver Posts: 46,084
    edited 2003-06-11 17:17
    Pat,

    I built a small project that required flows similar to yours. Your may
    be slightly lower than mine, but the solution should be the same.

    Check out:

    http://www.clippard.com/

    They have some great miniature solenoids, they advertise for use with
    air, but water can go through them also (but I doubt acid).

    Consider putting your liquid in a sealed container (I used 4" PVC pipe
    with a 4" caps glued on) and use the solenoid to allow air to enter the
    container, allowing liquid to come out. You may be able to create a
    small enough orifice to reduce your flows, or turn the solenoid on and
    off intermittently.

    I purchased mine from www.McMaster.com but there are other resellers out
    there too.

    I also got tiny fittings that fit the solenoid from McMaster, they were
    barb style hose connectors, and I put a small zip tie on the tubing to
    keep it in place.

    Let me know if you need part numbers, I'll look them up for you at home.

    Hope it helps,

    -John


    Original Message
    From: Pat M [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=E1b0_tmJGBIFWE9uSWgSmYa1dxSMYrh44_qTH3kC_aEWohfhi_C8yEe3WAgSVqTFj56G4YKB]pmeloy@s...[/url
    Sent: Tuesday, June 10, 2003 10:14 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] Very small pump or equivilent for caustic
    chemicals

    Thanks to invaluable assistance from Tracy Allen and others on this
    list, I
    have successfully made a full fledged prototype of a pool chemistry
    controll
    replete with 320x200 graphics LCD, trend log graphing (4000 sample
    history),
    serial output, pushbuttons, the works. Its based around the AVR Mega32
    now
    (needed the memory and I/O) but the stamp and this list is what taught
    me
    the majority of what I needed to learn. I'm just working on getting it
    off
    the breadboard and onto a PCB at the moment.

    As a stepping stone, I'm going back to an earlier design (no logging, no
    clocks, just displayed numbers at a 4 line text LCD) as a tool for
    teaching
    people how these controllers work. My BS2 will hopefully provide the
    brains
    for it.

    Anyway, I plan on using a 5 gallon bucket as to represent a swimming
    pool
    and I'm looking for ideas on how to feed in sodium hypochlorite and
    muratic
    acid. The amounts added will be very small and the solutions quite
    dilute. 1
    oz should take between 5-10 minutes to add and the feed rate needs to be
    variable. I need to simulate metering pumps (as used in real swimming
    pools)
    to show the affects of mismatched pump speeds etc.

    I've no experience with feeding these miniscule quantities other than
    using
    an eyedropper... Any ideas? My only (half formed) thoughts so far is
    some
    sort of miniature solenoid and gravity feed through a small plastic
    tube, or
    a small pump (like the Earth measurements kit one) and using short
    pulses
    spaced far apart.

    Merci!

    Meridian 59 is back! Sacred Haven - server 200
    www.skotos.net
    Original Message
    From: "acatano2002" <acatano2002@y...>
    To: <basicstamps@yahoogroups.com>
    Sent: Tuesday, June 10, 2003 7:13 PM
    Subject: [noparse][[/noparse]basicstamps] Play with DUALSHOCK 2


    > For those interested in playing with the BS2P and the Sony
    > DUALSHOCK 2 Controller, I created a small game.
    > Please contact me and will send you a copy.
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject
    and
    Body of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to
    http://docs.yahoo.com/info/terms/
    >
    >


    To UNSUBSCRIBE, just send mail to:
    basicstamps-unsubscribe@yahoogroups.com
    from the same email address that you subscribed. Text in the Subject
    and Body of the message will be ignored.


    Your use of Yahoo! Groups is subject to
    http://docs.yahoo.com/info/terms/
  • ArchiverArchiver Posts: 46,084
    edited 2003-06-12 03:47
    forget any type of valve or windshield pump. go directly to a
    peristalic pump. the tubing is the only thing connected to the
    chemicals and the pump is never near the stuff.

    the tubing gets squished and pushes out the fluid, one 'unit' at a
    time, and the squshed tubing regains it's shape and refils itself on
    each pump cycle. each pump revolution is one unit of chemicals.
    repeat to get the total quantiy you need.

    not hard to build and not hard to find, e-bay " Peristaltic Pump "
    and there are some great ones available.

    I remeber having one on the dishwasher at the restauranut I worked at
    as a kid for diswashing fluid.

    McMaster has them for retail prices so they are a common device.

    An alternative home brew would be to use an IV (think M.A.S.H.) with
    the chemical in the air, and a solenoid on the tubing. NOT good for
    true metering.

    yet another idea is a syringe. squeeze the tubing and it shuts off,
    unsqueeze and you get flow. a trio of solenoids could run in
    sequence.

    close ouput tubing
    open inlet tubing
    withdraw the syringe and it will fill.
    close inlet tubing
    open outlet tubing
    push on syringe to push stuff into bucket.
    repeat

    Dave
  • ArchiverArchiver Posts: 46,084
    edited 2003-06-12 13:07
    I've been searching ebay and google. Can't actually find any small
    paristalic pumps anywhere. Say one for $8,500.00 but I get the feeling thats
    not the one you're talking about [noparse]:D[/noparse]

    McMaster as in auto-parts place? I was searching there too and no paristalic
    hits.

    Meridian 59 is back! Sacred Haven - server 200
    www.skotos.net
    Original Message
    From: "Dave Mucha" <davemucha@j...>
    To: <basicstamps@yahoogroups.com>
    Sent: Wednesday, June 11, 2003 7:47 PM
    Subject: [noparse][[/noparse]basicstamps] Re: Very small pump or equivilent for caustic
    chemicals


    > forget any type of valve or windshield pump. go directly to a
    > peristalic pump. the tubing is the only thing connected to the
    > chemicals and the pump is never near the stuff.
    >
    > the tubing gets squished and pushes out the fluid, one 'unit' at a
    > time, and the squshed tubing regains it's shape and refils itself on
    > each pump cycle. each pump revolution is one unit of chemicals.
    > repeat to get the total quantiy you need.
    >
    > not hard to build and not hard to find, e-bay " Peristaltic Pump "
    > and there are some great ones available.
    >
    > I remeber having one on the dishwasher at the restauranut I worked at
    > as a kid for diswashing fluid.
    >
    > McMaster has them for retail prices so they are a common device.
    >
    > An alternative home brew would be to use an IV (think M.A.S.H.) with
    > the chemical in the air, and a solenoid on the tubing. NOT good for
    > true metering.
    >
    > yet another idea is a syringe. squeeze the tubing and it shuts off,
    > unsqueeze and you get flow. a trio of solenoids could run in
    > sequence.
    >
    > close ouput tubing
    > open inlet tubing
    > withdraw the syringe and it will fill.
    > close inlet tubing
    > open outlet tubing
    > push on syringe to push stuff into bucket.
    > repeat
    >
    > Dave
    >
    >
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-06-12 13:14
    Pat,

    That would be McMaster-Carr at http://www.mcmaster.com/, where you can get
    practically anything from motors and gears to raw titanium.

    Mike Sokol
    mikes@m...
    www.ModernRecording.com


    "Yes, we're mum and dad - and good and bad -
    and everyone's happy to be here.
    Genesis-

    Original Message
    From: "Pat M" <pmeloy@s...>
    To: <basicstamps@yahoogroups.com>
    Sent: Thursday, June 12, 2003 8:07 AM
    Subject: Re: [noparse][[/noparse]basicstamps] Re: Very small pump or equivilent for caustic
    chemicals


    > I've been searching ebay and google. Can't actually find any small
    > paristalic pumps anywhere. Say one for $8,500.00 but I get the feeling
    thats
    > not the one you're talking about [noparse]:D[/noparse]
    >
    > McMaster as in auto-parts place? I was searching there too and no
    paristalic
    > hits.
    >
    > Meridian 59 is back! Sacred Haven - server 200
    > www.skotos.net
    >
    Original Message
    > From: "Dave Mucha" <davemucha@j...>
    > To: <basicstamps@yahoogroups.com>
    > Sent: Wednesday, June 11, 2003 7:47 PM
    > Subject: [noparse][[/noparse]basicstamps] Re: Very small pump or equivilent for caustic
    > chemicals
    >
    >
    > > forget any type of valve or windshield pump. go directly to a
    > > peristalic pump. the tubing is the only thing connected to the
    > > chemicals and the pump is never near the stuff.
    > >
    > > the tubing gets squished and pushes out the fluid, one 'unit' at a
    > > time, and the squshed tubing regains it's shape and refils itself on
    > > each pump cycle. each pump revolution is one unit of chemicals.
    > > repeat to get the total quantiy you need.
    > >
    > > not hard to build and not hard to find, e-bay " Peristaltic Pump "
    > > and there are some great ones available.
    > >
    > > I remeber having one on the dishwasher at the restauranut I worked at
    > > as a kid for diswashing fluid.
    > >
    > > McMaster has them for retail prices so they are a common device.
    > >
    > > An alternative home brew would be to use an IV (think M.A.S.H.) with
    > > the chemical in the air, and a solenoid on the tubing. NOT good for
    > > true metering.
    > >
    > > yet another idea is a syringe. squeeze the tubing and it shuts off,
    > > unsqueeze and you get flow. a trio of solenoids could run in
    > > sequence.
    > >
    > > close ouput tubing
    > > open inlet tubing
    > > withdraw the syringe and it will fill.
    > > close inlet tubing
    > > open outlet tubing
    > > push on syringe to push stuff into bucket.
    > > repeat
    > >
    > > Dave
    > >
    > >
    > >
    > >
    > > To UNSUBSCRIBE, just send mail to:
    > > basicstamps-unsubscribe@yahoogroups.com
    > > from the same email address that you subscribed. Text in the Subject
    and
    > Body of the message will be ignored.
    > >
    > >
    > > Your use of Yahoo! Groups is subject to
    http://docs.yahoo.com/info/terms/
    > >
    > >
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-06-12 17:51
    --- In basicstamps@yahoogroups.com, Pat M <pmeloy@s...> wrote:
    > I've been searching ebay and google. Can't actually find any small
    > paristalic pumps anywhere. Say one for $8,500.00 but I get the
    feeling thats
    > not the one you're talking about [noparse]:D[/noparse]

    FlexiFlo III Digital Peristaltic Pump - Item # 2536966098 $49.00
    Clinitec 2200 enteral peristaltic pump - 2536966852 $49.00
    Peristaltic Pump - 2537187907 $25.00
    LKB ReCyChrom PERISTALTIC PUMP TYPE 4912A -2537700420 $19.00
    Rainin Rabbit-Plus Peristaltic Pump - 2537157965 - $9.95

    This is what is currently on e-bay under p-E-ristal-T-ic pumps.

    they are pretty large, but you can get smaller ones from different
    places like McMaster, but new cost big $$.

    If you are good at mechanical stuff, you can make one from a stepper
    motor and get good control, or even a DC motor and just time a pulse
    to get one-half rev or one cycle of pump per pulse.

    Dave



    Dave



    >
    > McMaster as in auto-parts place? I was searching there too and no
    paristalic
    > hits.
    >
    > Meridian 59 is back! Sacred Haven - server 200
    > www.skotos.net
    >
    Original Message
    > From: "Dave Mucha" <davemucha@j...>
    > To: <basicstamps@yahoogroups.com>
    > Sent: Wednesday, June 11, 2003 7:47 PM
    > Subject: [noparse][[/noparse]basicstamps] Re: Very small pump or equivilent for caustic
    > chemicals
    >
    >
    > > forget any type of valve or windshield pump. go directly to a
    > > peristalic pump. the tubing is the only thing connected to the
    > > chemicals and the pump is never near the stuff.
    > >
    > > the tubing gets squished and pushes out the fluid, one 'unit' at a
    > > time, and the squshed tubing regains it's shape and refils itself
    on
    > > each pump cycle. each pump revolution is one unit of chemicals.
    > > repeat to get the total quantiy you need.
    > >
    > > not hard to build and not hard to find, e-bay " Peristaltic
    Pump "
    > > and there are some great ones available.
    > >
    > > I remeber having one on the dishwasher at the restauranut I
    worked at
    > > as a kid for diswashing fluid.
    > >
    > > McMaster has them for retail prices so they are a common device.
    > >
    > > An alternative home brew would be to use an IV (think M.A.S.H.)
    with
    > > the chemical in the air, and a solenoid on the tubing. NOT good
    for
    > > true metering.
    > >
    > > yet another idea is a syringe. squeeze the tubing and it shuts
    off,
    > > unsqueeze and you get flow. a trio of solenoids could run in
    > > sequence.
    > >
    > > close ouput tubing
    > > open inlet tubing
    > > withdraw the syringe and it will fill.
    > > close inlet tubing
    > > open outlet tubing
    > > push on syringe to push stuff into bucket.
    > > repeat
    > >
    > > Dave
    > >
    > >
    > >
    > >
    > > To UNSUBSCRIBE, just send mail to:
    > > basicstamps-unsubscribe@yahoogroups.com
    > > from the same email address that you subscribed. Text in the
    Subject and
    > Body of the message will be ignored.
    > >
    > >
    > > Your use of Yahoo! Groups is subject to
    http://docs.yahoo.com/info/terms/
    > >
    > >
  • ArchiverArchiver Posts: 46,084
    edited 2003-06-16 06:40
    Pat -

    I have been following the responces to your question on what type
    of pump to use for metering in the chemicals to a pool control
    system. I would have to agree that the peristaltic pump would be the
    best option for you. If it is possible I would recommend getting one
    with a stepper motor rather than just a straight DC motor with speed
    control. I have worked for a number of years in the medical device
    industry and there are a number of instruments that use this exact
    technology. You may be able to find some of the parts you are
    looking for at an industrial liquidation store around you.
    I have been wanting to write and ask what type of sensors are you
    using in your system. We put in a pool last year and I have been
    trying to figure out how to build a monitoring system so my cholorine
    and pH don't get out of control. Your system sounds like exactly
    what I have been looking for. Any information you could share would
    be greatly appreciated.

    Thanks,

    Eric Warner
    Warner Consulting
    eric@w...
  • ArchiverArchiver Posts: 46,084
    edited 2003-06-16 12:26
    The problem with the peristaltic pumps (the ones I could fine) is that they
    are too large for this application. I am going to pick up two of them later
    on for my own pool - they seem better suited than the LMI reciprocating
    pumps we use in the commercial setting (and cheaper believe it or not!).
    Right now though I'm trying to feed a 5 gallon pail with a system that I can
    lug around with me from facility to facility around the city.

    Sensors are the easy part, though not cheap. I'll be using Acu-trol sensors
    since they're available locally and aren't horrendously expensive - last I
    saw they were about $250 CDN. There are knock-offs of these are around $170
    as well but I just had one die at one pool after just a few years so I'm not
    sure I trust them. (acu-sense I think the brand name was - close but not
    actually from acu-trol). Acu-trol says to replace the sensors every three
    years but I've had several in service for close to seven years and they
    still work perfectly.

    Just look up swimming pool dealers in your neighborhood - they'll have
    sensors in stock.

    As for the circuits - ORP sensors are easy - just hook them directly to an
    ADC and away you go. Its the pH sensors that are tough - the output current
    is in femto-amps so you have to run the signal through a couple of op-amps
    for conditioning before the ADC.

    Check out Tracy Allen's site for a pH sensor schematic
    http://www.emesys.com/OL2ph.htm then have a boo at my site for where I've
    gone with it http://members.shaw.ca/pmeloy/

    Meridian 59 is back! Sacred Haven - server 200
    www.skotos.net
    Original Message
    From: "ewarner77" <eric.warner@u...>
    To: <basicstamps@yahoogroups.com>
    Sent: Sunday, June 15, 2003 10:40 PM
    Subject: [noparse][[/noparse]basicstamps] Re: Very small pump or equivilent for caustic
    chemicals


    > Pat -
    >
    > I have been following the responces to your question on what type
    > of pump to use for metering in the chemicals to a pool control
    > system. I would have to agree that the peristaltic pump would be the
    > best option for you. If it is possible I would recommend getting one
    > with a stepper motor rather than just a straight DC motor with speed
    > control. I have worked for a number of years in the medical device
    > industry and there are a number of instruments that use this exact
    > technology. You may be able to find some of the parts you are
    > looking for at an industrial liquidation store around you.
    > I have been wanting to write and ask what type of sensors are you
    > using in your system. We put in a pool last year and I have been
    > trying to figure out how to build a monitoring system so my cholorine
    > and pH don't get out of control. Your system sounds like exactly
    > what I have been looking for. Any information you could share would
    > be greatly appreciated.
    >
    > Thanks,
    >
    > Eric Warner
    > Warner Consulting
    > eric@w...
    >
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
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