How does an iced tea dispenser work?

ironhorse

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I have been trying to figure out how a McDonald's iced tea dispenser will allow all of the liquid out, when the dispensing valve is in the middle of the container.

There is no outside power source for an internal pump. I have found that they call it a sump dispense valve, but I cannot find any mention of how it works. These dispensers can be purchased, but I have not found any description of how they actually work.

Anyone know, or have any experience with these?
 

bykfixer

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Ball valve or plug valve

A round ball with a stub sticking out of it and has a hole at a right angle to the stub. Turn stub with handle attached downwards to make the handle horizontal and hole becomes vertical, thus allowing liquid to flow through the hole.

The weight of the liquid squeezes past the hole.

Gas valves at places like your water heater use the same type ball valve system. Only those are generally brass where the tea dispenser is plastic.

Some use a valve operated by a spring pressure to keep the plug valve pushed up to keep it closed and pulling down the handle forces the spring down which allows a gap between the plug (or may be called a bung) and outlet to open up.
 

ironhorse

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No, they dispense to the bottom, or very near the bottom, per the product descriptions.

I understand how the valve works. What I don't understand is how the liquid flows up to the valve from below.
 

ironhorse

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From the product description:
"The sump dispense valve makes sure to drain out every ounce of fluid."

This is for a dispenser with the dispenser in the middle of the container. There is no mention of any power requirements, so that leads me to believe that there is no internal pump. What baffles me is the physics of having the liquid flowing up with no pump, siphon or pressure of the contents.
 

louie

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I assumed that the valve is actually the bottom of the liquid container, and that the lower part is just a base to elevate the valve above glass level.

I just looked around the Bunn Commercial iced tea dispenser catalog, but none of the documents I saw showed the actual cross section. I was going to look around Youtube for video showing the urns, but ran out of time today!
 

ironhorse

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I assumed that the valve is actually the bottom of the liquid container, and that the lower part is just a base to elevate the valve above glass level.

I just looked around the Bunn Commercial iced tea dispenser catalog, but none of the documents I saw showed the actual cross section. I was going to look around Youtube for video showing the urns, but ran out of time today!


I have not been able to find a cross section either but from a video, it would appear that you are correct. It appears the bottom of the inside is at the level of the dispenser valve and from the valve down is nothing more than an elevated base. I had assumed that the entire container was open on the inside.
 

louie

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I found some cross section drawings on the Bunn commercial site. We can't post direct links, so PM if you can't find them. I looked at the iced tea dispenser model TDO-4. There is a download tab of images and drawings. One of the drawings is cross sections of several models.
 

Empath

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We can't post direct links, so PM if you can't find them. ...............

Post your link, already.

We have no rule against posting links. As long as it isn't advertising in violation of our advertising policies, shilling or hotlinking, there's no problem with a link.
 
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