Water Chiller

[kleclerc77]

We are trying to get the right system for a closed loop cooling water setup. Our idea now would be a system that goes: cool water tank-->mash chiller-->hot water tank-->water chiller-->back to cool water tank. I didn't realize that the cool water tank also has to mix with the hot water tank before the hot water can go into the chiller. Water that is too hot is not good for the chiller. We are considering a 10hp or a 20hp water chiller, with 2100 gallon hot and cold water tanks. This is to cool a ~800 gallon grain-in mash. We are not looking to do more than one mash per day, nor are we looking to run the still at the same time. Do you think this system could keep up with our needs? Thanks everybody!

[kleclerc77]

Man I should post about more exciting stuff. But really, any insight is appreciated here. Thanks!

[Patio29Dadio]

I am busy designing a system for my new distillery.   I have come up with the need for three tanks.  Insulated cold water tank.  Hot water tank, and staging tank.

Chill the cold water over night to 50F in the insulated tank.  Condenser and mash cooling hot water discharge to the non-insulated hot water tank where it will naturally cool over night.  Before leaving for home, pump the water from the staging tank into the cold water tank and start the chiller circulation.  In the morning pump the water from the over-night cooled water from the hot water tank to the staging tank.

Repeat process.

I will need a dedicated water pump or two for this, but not too expensive.  Later I can work on automated controls. 

The initial problem I was running into is finding tanks that would take 160F-180F water.  Poly tanks cannot.  Also the insulated tank for the chilled water can be poly, but I don't like the way they look (a marshmallow as someone else described them) and they will sit next to my other shining equipment.  A 1000G custom cold-liquor tank and a 1000G hot water tank was breaking my budget.   So I got a quote for 2 sets of two 550G stainless totes that are stacked and will connect to fill as one set x2.   The staging tank is poly.

I continue to think this through and might tweak it before final purchase of equipment, but water cannot be wasted where I am located. 

[JustAndy]

I would suggest diverting as much hot water as possible into an insulated tank to use for mash water and cleaning water rather than trying to chill it. And use a cooling tower or similar to drain off as much heat as possible overnight before putting it through a chiller.  

[Patio29Dadio]

Quote

I would suggest diverting as much hot water as possible into an insulated tank to use for mash water and cleaning water rather than trying to chill it. And use a cooling tower or similar to drain off as much heat as possible overnight before putting it through a chiller.

 Good recommendations.  Unfortunately the roof of the building cannot be used for installing a cooling tower.

The other issue I think is that chilled water cannot be used for mash water unless the chiller is configured for potable water.  At least that is what I have been told.  And my chiller is not and I understand that this is an expensive modification.  I know of one distillery that just uses straight city water for their cooling (it comes out cold)... they save it in an insulated hot water tank and use it for cleaning and mash water.  But where I am located we have many days during the summer in the high 90s and 100s and the tap water will get to high 60s and even low 70s... thus the need to chill the condenser and mash crash cool water. 

I think what I came up with will work... having a 3-tank system with an insulated cooling tank, a non-insulated steel hot water receiving tank and a non-insulated water staging tank.  Pump the water from the staging tank to the chill tank before going home for the night and start the chiller loop.  In the morning drain the previous hot water that had been allowed to cool overnight into the staging tank.  Then run production where I empty the chilled water tank and fill the hot water tank again.   And repeat. 

[kleclerc77]

On 9/16/2018 at 12:20 PM, JustAndy said:

I would suggest diverting as much hot water as possible into an insulated tank to use for mash water and cleaning water rather than trying to chill it. And use a cooling tower or similar to drain off as much heat as possible overnight before putting it through a chiller.  

Due to the sizing of the fermenters and the size of the still, I do not see it being a possibility to mash with collected hot water. If that hot water sits around for any longer than overnight, microbial issues are a big concern. We could collect it for cleaning since it will be mixed with caustic and p3, but the water collected would still be way, way more than we need to clean. The city water is an adequate temp for cooling our mash, but I don't want to dump 1,500+ gallons of water down the drain whenever we mash. I thought chilling warm water was going to be a lot simpler than it is turning out to be. We are getting lots of conflicting advice from reputable chiller companies, so we are at a loss.

[indyspirits]

3 hours ago, kleclerc77 said:

If that hot water sits around for any longer than overnight, microbial issues are a big concern

If you're doing a bourbon mash you're going to hold it at 190ish for an hour which will kill any bugs.  

 

 

[MG Thermal Consulting]

On 9/16/2018 at 12:20 PM, JustAndy said:

I would suggest diverting as much hot water as possible into an insulated tank to use for mash water and cleaning water rather than trying to chill it. And use a cooling tower or similar to drain off as much heat as possible overnight before putting it through a chiller.  

Andy, 

Even a hybrid air-glycol cooler cannot cool enough glycol to chill water to 50F in summer, and I have used them in Duluth, MN. A closed loop from a cooling tower means adding a water to water exchanger, indoor sump, pump, water makeup treatment and filtration.  First cost seems smaller, but by the time you run this system for a few years, you see water makeup and treatments costs add up and wonder why the additional water and sewer costs are so high.

Diverting warm water must done with non-Ferrous piping, pumps, evaporator from the chiller, so for every concept, there is additional equipment added, or modifications to equipment that result in a higher cost.

Each capacity of each piece of equipment has to match up, capacity wise, which is why shell/tube mash coolers are used for large mash tuns- to account for small amount heat transfer relative to the chiller+reservoir concept.  For given temperatures, the smallest capacity equipment will dictate time for cooling mash.  

If the given equipment can't offer you enough assurance though experienced suppliers, then ask for references from satisfied customers.

I can offer hot water from a heat recovery chiller to neat 170F, but in order to make the hot water, you need twice (roughly) the chiller HP to do that plus reim cooler to take out hot refrigerant when your hot water storage is maxed out.

It all depends on what is more important, water heating, quick turnaround on cooling or smallest first cost.