3 Heat exchanger questions...

[Catfish002]

1) Do you recommend a dual pass or a single pass plate heat exchanger for a 7 barrel brewery? Also, how many plates in the heat exchanger do you recommend for a 7 bbl batch?

2) We are needing on the outlet on our heat exchanger to have a triclamp thermometer, oxygen stone and sightglass. Does anyone know if there is a that company sells a set up like this already made for the outlet on a heat exchanger? If not, can someone walks us through on how to build one?

3) Once the beer is transferred from our brew kettle through the heat exchanger and into our fermenters, how are you guys getting the remaining wort out of the heat exchanger and hose into the fermenter? We want to capture as much wort as possible in our fermenters!

Thank you so much for your assistance!

[OneMoreBrewer]

The answers to these questions are subjective. Are you making ales or lagers? what is your desired strikeout temp? Number of plates is rather irrelevant. You are more concerned about surface area contact. How big are the plates? That effects how many you need. How long do you want to take to strike out? The more surface area the quicker. Are you using city water to cool or cold liquor? With cold liquor I see no need for a dual stage. Do you plan on recycling your now heated water or just down the drain?
As far as thermometer, oxygen stone and sight glass, just put them inline after the exchanger. Output, triclamp tee, aeration stone on top, another tee on bottom, temp probe on the side, and sight glass on the bottom. Then a butterfly valve. Then hose to cellar.
Chase the last of the wort with water, preferably filtered non chlorinated. Switch off the chase water to a dump tube as wort begins to dilute.

[CPESystems]

Dual vs single pass

A properly designed dual pass allows more contact time for the water so it is more efficient and the water comes out at a nice hot (175 F) temperature to put into your HLT.

[Peter Metaxas]

Heat Exchanger

Catfish,
The other answers to your question are great, can I add the following info as a general principal to any heat exchanger application, brewing or not.

The length of the channels in the plate that the fluid goes thru is goverened by the physical length of the heat exchanger plates and the number of passes. (Fluid = water or wort or glycol or what ever)
Lets say the plates in the heat exchanger are 30 inches long and 8 inch wide.
In a single pass unit the fluid travels the 30 inches, in a 2 pass 60 inches and in a 5 pass the path the fluid travels is 150 inches.
The longer the fluid stays inside the heat exchanger (residence time) the closer you can bring the hot fluid temperature to the cold fluid temperature,
So if you want to cool from 210 down to 60 by using a cold side fluid which is at 55 then you need to have a long path. If you only wanted to cool from 210 down to 80 the path can be shorter.
The difference between the final temperature of the hot fluid and the starting temperature of the cold fluid is called the approach temperature.
So cooling from 210 to 60 with a 55 fluid is a 5 deg approach.
You achieve this by using either a single pass heat exchanger which has very long plates (not practical) or use more than 1 pass of a shorter plate design.
We have seen DME use 5 pass exchangers.

The amount of fluid that you want to process in a given length of time will determine the physical size and number of the plates.
So with a 7 bbl system you you most likely need a small plate size.

From my experience a long single pass or a 2 pass heat exchanger is usually sufficient. Some where about $2800 to $3600.

A single pass is a bit easier to reassemble after you take it apart and clean it.

I'll write some more later when I have a bit of spare time.
Regards
Peter