Temperature Controlled Grill

[billman]

Hey Guys
New here but long time BBQ Fan.

I need some advice. I am in the process of installing a Temperature Controller on my LP Gas BBQ Grill. I've acquired a PID Controller and a Solenoid Valve.

I have the following setup in mind.

1. Install a Pilot light into the Gas Grill directed at the Gas Burners.
2. Solenoid valve will control the gas flow to the Gas Grill
3. The PID Controller will open solenoid valve when the temperature is below the set temperature on the controller.
4. Once temperature is reached on the PID Controller, the controller will close the solenoid valve which will seize the gas flow.

My biggest concern with this setup is if the Pilot light goes off, the gas will build up and you know the disaster that could cause if just a spark has to hit the gas that collects in the burner. Is there anything I can install to completely shut off the gas if the Pilot Light turns off?

If you have any other suggestion for a better setup, please feel free to discuss.

Take Care

 

[daveomak]

Yes... A flame out sensor.... It operates on the flame from the pilot flame... No flame.... gas shuts off.....
Some back yard turkey fryers or crab cookers have the flame sensors ... aftermarket are available...
I don't have any in mind at the moment....
Maybe some members have a thought or two...

Search this on Amazon, as an example....
Monessen 14D0477 LP Gas ODS Milivolt Fireplace Pilot

 

[billman]

Thank you daveomak - sounds like exactly what I need.
I've got some direction now - just need to find it.

 

[chopsaw]

I dont see that working . How many burners is it ? A furnace works off of 1 pilot light , but has a ignition rail that feeds the burners to all light at once . Seems to me that you would have raw fuel searching for ignition .

 

[billman]

The grill has a single igniter and all the burners join up somehow - I would place the Pilot Light next to the igniter.

 

[daveomak]

What do you not see working ???

 

[chopsaw]

What do you not see working ???

If he has a single ignition it should be fine . I saw it as single igniter for each burner .

 

[daveomak]

He would have to run a pilot to each burner for re-ignition after a temp shut down, in order for it to start up again as the controller called for more heat...
the single controller would still shut off the primary gas supply when the pilot went out...

 

[chopsaw]

Yes that or have an ignition rail like a furnace . That was my concern .
I should have been more clear. I was commenting on re ignition . Not the flame out .

 

[solman]

see my the mod link in my signature. i've done exactly what you're looking to do, although your definition of pilot light may differ slightly from my setup.

 

[billman]

see my the mod link in my signature. i've done exactly what you're looking to do, although your definition of pilot light may differ slightly from my setup.

Hey Solman

Sorry to be responding so late - I completely forgot to check your setup after receiving a notification of your reply.

You have done exactly what I am looking for - if you don't mind me bombarding you with questions once I start putting together a similar solution, I will just keep it to 1 question for now.

How does the Thermocouple Shutoff function?

Thanks

 

[solman]

i'm not exactly sure how it functions. a quick google says the heated probe sends a voltage signal to the shutoff valve to keep the valve open, once it cools, the voltage drops and shuts off the valve. https://www.thespruce.com/replacing-water-heater-thermocouple-flame-sensor-1824918

 

[billman]

Hey Guys
So.... ever since my last reply, I went all out to buy everything I needed to undertake this project and they it all got side tracked due to time constraints.

I finally managed to pick this project up again and I got as far as hooking up the Solenoid Valve to a PID Controller and then to my Gas Griller. The PID Controller opened the Solenoid Valve when the temperature was below the set temperature.

Then..... I got stumped with a problem
When the Solenoid Valve Opens, the gas flow to my griller is too low that it barely has a flame. If I blow into the Solenoid Valve when it's open, it takes some effort to get enough air come out on the other end.

I checked the pressure range of the valve and this what it says
Pressure Range: 0.02-0.8Mpa
My gas Regulator Pressure Range is 2.8KPA

I'm not all that clued up with understanding these measurements - hopefully someone can provide some insight how to get around this problem.

Thanks

 

[daveomak]

Get a low pressure regulator..
Try and get the flame height close and just above the required temp in the smoker..
The best way to do that is...
Adjust the length of the burner to provide the required temperature, while the gas flow is adequate....
Some members have attained that gas flow/flame height by doing this...




......

 

[billman]

Hello Daveomak
Thank you for responding

My regulator is a Low Pressure one but it isnt adjustable - I suspect the regulator has too low pressure to push through the Solenoid Valve. I'll try and take some pics to further clarify my situation.

 

[solman]

My regulator is a Low Pressure one but it isnt adjustable - I suspect the regulator has too low pressure to push through the Solenoid Valve. I'll try and take some pics to further clarify my situation.

i think it might be your solenoid. the low end of your solenoid's working pressure is .02mpa, which is around 3psi. a low pressure regulator is <1psi.

 

[daveomak]

The solenoid may restrict the flow too much... Is the solenoid designed for a gas appliance ????

 

[billman]

solman, I'm thinking the same - I dismantled my Solenoid and it seems that the valve is almost like a flap that requires a bit of pressure to open it once the solenoid is energized. I guess the pressure from my Gas Regulator isn't enough to do that - this is the valve I have
https://www.banggood.com/AC-220V-1-...r-p-914444.html?rmmds=search&cur_warehouse=CN

I've been looking at your project again and notice the Solenoid Valve you use is one similar to this - what do think, will this work better - I'm thinking of ordering it.
https://www.banggood.com/12-34-1-In...eft-hotproducts__3&ID=518829&cur_warehouse=CN


Daveomak - not sure if it's designed for Gas - it did say air in the description so I though it would handle gas flow.

 

[solman]

I've been looking at your project again and notice the Solenoid Valve you use is one similar to this - what do think, will this work better - I'm thinking of ordering it.
https://www.banggood.com/12-34-1-In...eft-hotproducts__3&ID=518829&cur_warehouse=CN

Based on the specs i don't see why it wouldn't work if you're planning to use a 220v power source. My solenoid is a valve type that goes up and down, versus this one that appears to rotate. No idea which is better but they both do the same thing, open and close as needed.

 

[billman]

Hi Solman

I've been taking tips and ideas from your design and hope you don't mind me posting a picture of it with labels and a few questions I have

Firstly, the way I understand your's to work is as follows.

Your LPG/Propane tank connects directly to (A) which I would term as your Gas input. The Gas then flows through the solenoid (C) if it's opened and goes out through (B) which I would term as your Gas Output. (B) is connected directly to your smoker.

Questions I have

1. D looks like a Manual Valve to me and I'm not sure the function it plays in your setup since if D is open and the Solenoid closes, Gas will still flow through D and out B.

2. You mentioned a Safety Valve which I understand to be connected to a Thermocouple which shuts off automatically should the Pilot light go out - Where does it go in your Diagram?


Thanks again for all your assistance and guidance - greatly appreciate it.