Valve to fill additional compressed air tank

I wired an Allen Bradley PLC 5 to a Brinkman Gourmet Electric Smoker. Had a PanelView 550 for operator interface. A RTD probe for the meat and another for the temperature inside the smoker. The meat set point temperature ramped up over 12 hours as the smoker temperature was kept within limits. After the temperature was reached, it was held for a period of time to allow it to even out, then brought down to a set point of 140 degrees for "keep warm". It worked great but was a pain to drag out & set up then put back up. I need to mount the controller in a box and use plugs for the temperature probes and power. It was done for fun but made pretty good BBQ, need an automatic smoke wood feeder!

Next step I could use some actuators for the air inlets and control my Weber Smokey Mountain smoker!

PLC 5's are a bit old but their cards are cheap since the 1771 racks date back to PLC 2's. The downside is the programming software but I have it on my work laptop.

RogerN

What is OK for an outdoor smoker, is not OK for an indoor wood fired stove, a much more dangerous device.

i

True, if you make a mistake with the program, you may never find out!

However, about everything that can be sensed with electronic sensors can be fed into a controller and acted upon or at least sound an alarm. So, on a wood stove you could monitor temperatures, carbon monoxide, or any other relevant conditions that you might want to monitor on a wood stove. Controls checking and acting on conditions hundreds of times per second can catch and correct a problem better than a person can.

I used to attempt to fly R/C helicopters before Gyro's were common to assist tail rotor control, probably averaged 1/4 tank of fuel between crashes. After purchase of a cheap mechanical gyro, next crash was around 70 full tanks of fuel later. The crash after 70 tanks of fuel was due to getting it too far away and losing orientation, not a control or gyro related problem.

RogerN

I share Iggy's concern enough that I don't run the stove when I'm away. In midwinter I came home from work to a 50F house, the setting of the electric backup.

The control I was considering would have closed the air inlet on the door as the stove came up to temperature. I didn't add it because I don't want any possible interference if the fire runs away and I need to shut it down.

After Thanksgiving I let the house cool to measure the rate vs outdoor temperature. At 2AM on Saturday the smoke alarm blasted me out of bed, to the smell of something electrical that had overheated. I rushed around checking all the electronics, found nothing warm, rechecked them twice anyway. Then I noticed that the smell was strongest near the hallway radiator, which hadn't been disassembled and vacuumed out in a long time. I had forgotten about the backup setting. The radiator had turned on, and the alarm and hot plastic smell were from rug fibers in it.

jsw

What fun!

I woke up to some fun this morning. -=No water=- The pump pressure is up but the lines are frozen. I put a heater in the pump house (the light had burned out, allowing the freeze?) an hour ago but no joy yet. I'll put it in the crawlspace in a few minutes and see if that does it.

It has been 10 or 11F here two days in a row. The lowest I've seen here before is 17F, and my outside line burst 8 years ago. I have insulated the exterior pipes and shut them off for the winter now, so this is the first problem I've had, and the first time losing water. There's a shutoff valve for each inside and outside lines.

Crap!

I bought a 200W Lasko personal heater for $12 in WalMart to see if it can keep my water meter above freezing when I'm away without running up an excessive electric bill. Right now it's defrosting dinner. It could be wired through an electric heat wall thermostat as a backup to the light bulb that distributes heat differently, like downwards or through a conduit.

For the light bulb:

jsw

Wow, aren't those little cuties? That's much better for ladies' feet under the desk than a 1,500W energy sucker. I wish I'd seen that earlier today when I visited Wally World for my prescription, which just left the $4/mo list and cost me $15.68 instead. Big Pharma ended their price deal with Wally and bumped prices a wee bit! The Lasko MyHeats are $18.62 today.

Dinner, eh?

That's a thought.

I've been wanting to replumb in PEX and insulate the crap out of it when done, but the ongoing recession took care of that for me. Red Beacon (thru Home Depot) is bringing more work to me during the wet season than ever before, so I may be able to afford that next year.

Hmm, I may do that some day...

3:30pm update: Shit, still frozen shut. I had warmed the pump house for over an hour, then put the heater aimed at the pipe in the crawlspace for about 4 hours, but it's still frozen. Temps had risen to 31F for awhile, but are back to 28F now and dropping. Rain is due Weds, so I hope to have water again by then.

I saw no indication of burst pipes during my quick foray under the house. The visqueen was dry to the end. I'm keeping my fingers crossed.

Been there and done that. Not fun. If the pipes are metal , you can hook an Ac welder to the pipe with one connection to each side of the frozen se ction. Put the welder on the lowest current and turn it on. The current thru the pipe will heat the pipe enough to allow a trickle of water . And the trickle of water will melt more of the ice in the pipe.

A good long term solution is heat cable made by Raychem. It is a cable tha t does not draw much current when warm and more when cold. Look on the int ernet for better write up.

Dan

Compressor output to inlet. Outlet to primary tank. Exhaust to secondary tank. Plug the throttle port.

Second line between tanks with check valve blocking flow from primary to secondary.

Startup of morning - secondary tank will be empty until primary is at

120. Then flow goes to secondary until primary drops to 90. Secondary will fill in increments. If primary usage keeps pressure below 90, no air will go to secondary.

Your pressure switch should be set 5psi higher than the unloader pressure so the pump doesn't turn off every time the unloader cycles. When the pump does turn off, both tanks will be at the same pressure and with usage, will bleed down together.

My power outage emergency shower is a garden spray tank with a sink spray hose replacing the wand. I removed the dip tube and jammed 3/8" tubing into the tank outlet.

I heat a kettle of water on the wood stove, mix it to tolerable temperature in a pail, then fill the sprayer in the shower where spills don't matter. You could add a saucepan to scoop hot water from the kettle to the pail so you don't risk spilling it on your feet, and a bungee cord to hold the tank upright. The 2 gallon size of sprayer is a reasonable balance between running time and ease of handling when you and it are slippery with soap.

In the summer the sprayer is stored out back as a quick-reaction fire extinguisher. The modification makes it obvious that it isn't for chemicals. jsw

Sounds like a winner, and something which could be used after the fall of civilization. (I'm soooo positive, aren't I?)

Excellent. Showering in RoundUp residue wouldn't do, would it?

UPDATE as of 10:45pm last evening: I have hot water! It was back down to 20F when the hot water suddenly came back on. I guess my day of heating things took a long while to work, but finally did. Whew! I have a hot cup of coffee in me and now it's off to the shower.

Also I don't want kids spraying each other in the face with pesticide. I bought a new sprayer for this. jsw

probably not. The 90-120 psi stuff is just a distraction from the real problem. you don't want to fill the large tank when there's a load on your compressor from tools. Pressure on the system doesn't truly indicate if you have a load or not.

I don't deal with air systems, maybe somebody can answer this-

do they make simple flow guages or sensors for compressed air systems?

If so connect both tanks with a check valves in a Y, allowing flow out to your load, but no flow between tanks. The connection to each tank from the compressor is with a solenoid valve in the same Y configuration. The only states are compressor connected to no tank, connected to the small tank, connected to the large tank or connected to both tanks.

back to the flow detector-

When you detect a load on your system, disconnect the large tank from the compressor. Only the small tank is connected to the compressor. It will fill quickly so nobody is standing around.

If there is no, or low tool load, disconnect the small tank from the compressor, and connect the compressor to the large tank. The air supply to your load will be from the tank with the highest pressure, which is the small one. Immediate usage needs are met.

When the pressure there (small tank) drops too much, you start the compressor and disconnect the large tank.

Add a pressure sensor to the large tank. Once it hits minimum acceptable pressure (90 in your case) leave both valves from the compressor to both tanks open. You're now using the capacity of both tanks and the fill of the large tank never interrupted with your immediate use requirements.

You need a little logic to run this, but it's nothing beyond a couple relays.

This is completely untrue.

There is nothing wrong with filling secondary tank, and using tools at the same time, as long as the system pressure is adequate (above 90 PSI for tools).

Whatever you describe, is not hard to do with pressure switches and relays.

i

have at it.

you solved your own problem in the most clever way possible. it's brilliant. job well done.

Google Backpressure Regulator - Fisher makes them, and probably others. Holds off flow till the feed side is above a minimum.

We used them at Ye Olde GTE so that the underground cables always had ~9 PSI on them even if someone opened the aerial to work on it, rather than let the whole pipeline see a 'zero leak'.

Which is important if one of the manholes in the underground is full of water and also has a tiny leak on a case, you want to maintain pressure going out than have water coming in - if it's paper insulated cable, just a few drops of water and you're in huge trouble.

Even with Plastic insulated cables it can be real bad - Call it in if you ever see a flooded street with a little string of bubbles coming out of the phone manhole. If someone lets the pressure off somewhere else on that lead to work on a cable...

Thanks.I will check them out.

They have them in air braked trucks too for the secondary system (wipers etc).

Interesting.

i

OK, I got this nice tank, I may try your suggstions with it.

240 gallon Sylvan tank:

Look closer. Compare it to garbage cans next to it. The one on the very right is a 44 gallon Brute cans.

I personally hope that it is a 240 gallon tank, but I will know when we bring it in.

Buy you did not rebuild the air end itself, right?

i