What is the Difference Between a Process Chiller and a Waterjet Chiller?

Hi, we’re here today with Mark Hensley of Hensley thermodynamics and we’re going to explain the difference between the process chiller and a true waterjet chiller.
Now, Mark, you’ve got an extensive background in Thermodynamics. You were trained by the US Navy in nuclear physics in the 1970s and then you went through extensive training in the air conditioning and refrigeration business, and started and ran your own business for a number of years. So why don’t you go through … tell us what this machine will do and why it’s different than what’s normally used for a waterjet.

Mark: A true waterjet chiller differs from a process chiller. A process chiller has been designed for processes like if you are cooling plastics or food processes where you try and maintain a narrow band of temperature to control a process. Up to now, the waterjet industry has been using process chillers to do this.

When I bought my waterjet machine and being a cheapskate like I am, they wanted $10,000 to $12,000 for 3-ton chiller for mine and I looked it and went “This is a process chiller, why would you want a use a process chiller on a waterjet machine?” So I designed and built my own, and the differences between is that it doesn’t try to maintain that narrow band of temperature, instead I can let this unit run, maintain its efficiency, chill down a storage tank of water, and shut off and still remove all the BTUs out of the water that I want to maintain. So as I built this, my salesman for my waterjet machine showed up and said “You know you really need to have a chiller and at that time I went ahead and showed him mine and next thing I knew I had engineers crawling all over this thing so they asked me if I would start building them for them and since then, I’ve come up with this recirculating one that’s about 85% more efficient than a process chiller. It’s certainly a lot quieter.

Let’s start it up and go ahead and let it run and I can show you some of the main things… what it does. The other thing about process chillers… process chillers will only really give you a 20-degree temperature differential… maybe 30%.

Omax® had been testing these and we were dumping straight dump water which was 204 degrees and it was coming out 74 degrees. So our temperature coming in right now is right at 100 degrees… the outgoing is running about 52 degrees. Now waterjet machines whether it’s an intensifier or whether it’s a flow through, it just likes water that’s below 65 degrees. It doesn’t care about if it’s maintained in the narrow band. The colder it is the better it likes it.

Why does it [waterjet machine] need the cold water?
Well, on a flow-through chiller, it keeps the seals cooled down to the right temperature where you can get the maximum wear. On an intensifier type or recirculating type chiller, it maintains the coolant temperature within the heat exchanger of the hydraulic oil down at a low temperature and it stops you from just wasting water. A lot of these people use an intensifier pump and then they just dump all their water into the sewer. Well with water being so scarce, this allows them to completely recirculate that water that they’d be using for the cooling of their hydraulic systems and save that money as well as be eco-friendly.

Now, what if they don’t want all the heat that this is going to produce?
It’s easily removed by any air conditioning refrigeration man. He can put this thing up to 200 feet away and just leave the cabinet inside if he doesn’t want the heat or this noise (that’s below 74 dB) in there. I tried to make this very user-friendly. This condensing unit is a 3-ton Ruud condensing unit, but basically, any condensing unit could be on this. Same things with all the parts that are in here [the cabinet], too. I’ve used parts that are easily available at any air condition wholesale house because people such as myself, we don’t want to be down waiting for some special OEM part to come from the manufacturer. So on a waterjet, if my chiller goes down, I need to be able to get back on the line in just a matter of hours instead of a matter of days or special overnight shipping or they don’t have the part or whatever the problem is.

You were able to take that really hot water and cool it to the temperature that is best for the machine.
Sure, and where a process chiller wouldn’t be able to do that. A process chiller needs to run constantly and be constantly unloading… it’s designed specifically for an industry that needs specific cooling parameters. A waterjet doesn’t. It just wants water below 65 degrees.

Well, Thank you very much!