This is a photo of my current RIMS brewing system, which is a two-tier / three-vessel system with the RIMS located in the middle. The frame is constructed of wooden 2x4's that are bolted together using 2-1/2" to 3" long bolts and screws (you don't want this thing wabbling under the weight of full boiling kettles). The frame legs have wheels that can be locked down in place once I roll it out from the garage. From left to right you can see the boiling kettle, the mash/lauter tun (with insulation), and the hot water tank elevated above the other tanks to allow for gravity flow. The large vertical copper pipe to the right of the mash tun houses the heating element. The grey box at the bottom of the heating element piping is a water-proof GFCI-outlet housing where everything plugs in. The silver box to the right of that is an old computer power supply box that houses my new PID temperature controller. The pump is located below the center mash tun and is mostly hidden by the framework. The two vertical poles on the two end kettles are liquid level sighting glasses.
There are many other setups that you can use besides this, so use your imagination. Some people have their entire system gravity fed (three-tier), others have all vessels on the same level (usually requires an additional pump), and some use only two vessels with one doing double-duty as both the hot water tank and the boiling kettle. Other ideas include using only one propane burner that is mounted so that is can slide back-and-forth under the appropriate kettle.
The next step is to walk you through the construction of the RIMS. I think the most logical order would be the order in which you use them, starting with mashing in the mash tun....
Here you can see that my mash tun is well insulated. I wrapped it with insulation purchased from a hardware store that is made for hot water heaters. I also cut a hole in the top of the lid of a plastic bucket to further reduce the heat loss to the atmosphere. The better you insulate, the less your heating element will have to work.
The silver colored tubing is connected the the elevated hot water tank to the right. I use this only when mixing hot water with the freshly crushed grains (doughing-in) and when sparging. Otherwise, it is folded out of the way. You can also notice in the lower right corner the red handle of the ball valve that I use to control the flow rate during recirculation.
Once the mash tun is complete, the false bottom is constructed and placed in the bottom of the mash tun to hold the grain bed up while allowing the wort to circulate through it. My false bottom is made out of two pizza oven screens with an aluminum screen sandwiched between the pizza screens. These pizza screens are made of rigid aluminum. I bought them at Wal Mart and bolted together so that the diamond shaped holes are oriented at 90° angles to each other. This setup gives a very large percent-open-area for my false bottom, which is important for a RIMS system. If your false bottom does not have a large enough percent-open-area, then your pump may try to pump the wort at a rate faster than it can naturally flow through the false bottom. If this happens then the pump might create a suction below the grain bed that is strong enough to cause the grain bed to compact and thus restrict even further the rate of recirculation.
There has been some concern in the past about the use of aluminum in making beer. A recent study initially concluded that high levels of aluminum were found in patients with Alzheimer's disease, and that there was possibly a link between the two. However, recent follow-up studies found flaws in the previous experiment. Apparently the aluminum actually came from the test solutions used in the experiment and were not from the brain itself. Therefore, I would not be too concerned about the use of aluminum pots or pizza screens in your brewery.
This is a close-up of the underside of the mash tun. Besides wrapping the vessel in insulation, you can also see that I have sprayed the bottom with an expanding foam for additional insulation. A ball-valve, placed just on the underside of the mash tun, allows me to dough-in my grains with the valve closed before opening it prior to recirculation. The pump is a Teal brand pump model #1P677A which I bought from W.W.Grainger for about $85.
There are other brands of pumps to choose from, and you might be able to save some money if you buy from a surplus catalog, but you should always look for a magnetically coupled pump when building your RIMS. A magnetically coupled pump is one where the motor drives the impeller of the pump through the interaction of magnets. This allows for the pump head to be totally isolated from the motor shaft so that the wort never comes into contact with the motor, which is beneficial for obvious sanitary reasons. Furthermore, this magnetic coupling of the drive shaft and the pump head allows you to be able to control the pumping rate by simply putting a ball-valve on the outlet side of the pump. You can even close this valve completely without damaging the motor of the pump because the magnets will simply de-couple and the motor will not burn up. However, you should not place this control valve on the inlet side of the pump, as the pump will then run dry and may become damaged.
Some people choose to control the speed of their pump electrically instead of restricting the flow with a ball valve. Do not attempt this using common dial dimmer type switches since they reportedly can damage the pump motor over time. However, according to both Dion Hollenbeck and Evan Kraus, you can safely use a ceiling fan speed controller. Be careful not to slow the pump motor down too much though. The motor acts as its own cooling fan and you can actually overheat it by slowing it too much. For this reason as well as price, I still prefer the ball valve.
After the wort flows out of the mash tun, down through the false bottom, and through the pump, it then travels into the heating chamber. The large copper vertical pipe in the center of this photo is 1.5" in diameter which houses the heating element that is used to maintain mashing temperatures. At the top you can also see a large dial bi-metal thermometer that I use to verify the temperature readout of the PID controller (redundant and probably unnecessary) and also a plastic cup that covers the exposed wires of the heating element so some idiot (like myself) doesn't rest his or her hand on it! Near the bottom are two boxes. The grey one is simply a water-protection cover for the outlets where I plug everything in. The metallic box to the right of this grey one houses the PID temperature controller..... the brains of this outfit! About midway up to the right of the copper heating chamber is a small black device. This is called a Solid State Relay (SSR) and it is the interface between the PID and the heating element.
Before the recirculating wort enters the heating element chamber, it crosses the tip of a thermocouple so that the PID can read the temperature. In this photo, the wort is being pumped up from below before making a couple of turns up into the heating element chamber. The thermocouple consists of the black rubber stopper on the right with the blue wiring coming out of it. The part you can't see is a 4" sharp metal probe that is inserted horizontally into a white rubber stopper that I glued into the end of the "T" fitting. I purchased this type-t thermocouple from Cole-Parmer because they had slightly better prices ($15, Part# DW-08439-24). This is a penetration style probe with a sharp point for sticking it through the rubber stopper into my plumbing. It comes with a jack/plug on the end that you will need to cut off so you can wire it to the PID. Since the polarity is important when wiring it to the PID, just remember that the red insulated side is negative and the blue side (copper wire) is positive.
The wort now flows up into the heating element chamber where it may or may not be heated depending on what temperature the PID sensed with the thermocouple. The design of the heating element chamber is not as trivial as it may first appear. My first attempt used a small, 8" long element rated for about 1500W at 110 volts. The problem was that this small element (ie small surface area) created too high of a "heat output density" and the wort scorched as it flowed over it. I didn't realize this was happening at the time, but as Murphy's Law goes, my element finally became encrusted in burnt, caramelized wort and died the day I invited the entire brew club over to see a demonstration. Needless to say I have since replaced this unit with a more appropriately sized element. I now a have an element that is 13" long, but is actually almost twice that long because it is doubled over on itself. It is rated for 4500W at 220volts, but I'll only be wiring it at 110 volts so the wattage will be around 1200 (when you halve the volts, you approximately quarter the wattage). Therefore, I'm actually back around my original heat output in wattage (a little less) but it is spread of over the much larger surface area of the longer heating element. Thus a "low heat density output" and no chance of scorching!
Another lesson from this is that your element should probably be removed periodically for cleaning, even if you don't undersize it. Dion Hollenbeck reports a thin grey fuzzy film covering his element after every batch that must be cleaned, while others report elements that look like new after multiple uses. To be on the safe side, I'd design mine for easy access. Thus the easily removed plastic cup covering the end of mine!
This little device is the PID, the brain of the system. I purchased it from Omega Engineering, Inc. for $165 (Part #CN8590-DC1). The engineers at Omega were very nice and helpful while helping me decide exactly what parts I needed. The PID is actually a very cool little device. PID stands for Proportional, Integral, and Differential. Other than telling me that it uses calculus, I have no idea how it works. Once wired, I simply had to tell it it was using a type-T thermocouple, then put it in auto-tune mode to learn my system. Since every system reacts differently (for example oil would take longer than water to heat) it needs to learn how your system reacts so that it can ramp to the set point temperature as quickly as possible without over shooting it. Once it learned how my system reacts, it filled in the P, I, and D variables automatically. To "teach" it, I simply placed some cold tap water (62°F) in my mash tun, turned the pump and PID on, and placed the PID in auto-tune mode while trying to heat it to 155°F. Now that it knows how my system reacts to heating, I can walk away from the system while it automatically holds my mash temps for me without varying even one degree. Stepping up to the next mash temperature is a simple as dialing in a new set point on the digital display and walking away (to take a nap, or read the morning paper, etc.)
For the PID to properly control your heating element you will also need to purchase a Solid State Relay (SSR) from Omega (about $24, can't remember part#) which the PID uses to control the heating element. The SSR is a small electrical device shown near the top of this photo that has the PID wired to one side and your heating element wired to the other. The PID can then turn the element on by supplying a small voltage to the SSR which closes the circuit on the other side for the element. In addition to the SSR and PID, don't forget your type-T thermocouple for sensing the temperature of the wort, which can just barely be seen to the far left.
After flowing up through the heating chamber, the wort has almost completed one trip through the RIMS. Here you can see the top of the heating element chamber with the wires exposed. Also, notice the red handle of the ball valve that is used to control the speed of flow. This is typically the position that I keep it at during recirculation. The wort now flows through a short piece of plastic braided tubing into my wort distribution manifold
This is a photo of my returning wort distribution manifold as you are looking down into the mash tun (the false bottom has been removed). The design is a modification of Dion Hollenbeck's star-shaped design, although I think this "H"- shape works just as well and is easier to build. It is just six lengths of 2" x 1/2" diam. copper tubing, three 1/2" diam. "T" fittings (one in the center and two one each side of the "H"), and four 1/2" diam. "L" fittings on the outlets which I soldered together using lead free solder. After the wort is pumped from the bottom of the mash tun, across the heating element and back to the top of the grain bed, it flows out of this manifold. The unit rests on top of the grain bed and is submerged by about 1" of wort. The wort then flows out of each of the four upward turned ends and gently flows back down into the grain bed. This prevents the flow from disturbing the grain bed, which is acting as your filter bed to keep the wort crystal clear. Even at full pumping speeds the wort flows out of the four outlets gently. When designing this manifold for a 15 1/2" diameter kettle, I calculated that each of the six legs of the "H"-shaped unit should be about 2 1/2" long. I cut each of the 6 pieces about 2" long, so that the additional length added by the "T" and "L" fittings made the length of each leg approximately the correct length. This placed each of the four outlets near the centroid of its respective quadrant for even distribution of the recirculating wort.
The wort now continues on another cycle through the RIMS.....