Kiran Patil

Missed to attach this picture in my previous post.

So,

Finally the Rocket oven is installed.

These are the features-

1. Most part of he J tube is constructed in insulating fire bricks .

2.Ends of the J tube are layered using high density fire bricks. Morter for layering the bricks is 2:1:1 mix of sand, fire clay and Portland cement.

3. The oven is a black type rocket oven. We used two barrels. A clean and fresh barrel for inner part and a scrap barrel for the outer layer. Heat riser enters about four inches into the inner barrel.

4. Glasswool insulation is used between the two barrels.

Still some work is pending -

1. Installation of flu
2. Layering the inner barrel with about an inch of refractory castable
3. Layering of hearth - I accessed some used fire bricks for hearth.

We fired it up for about ten minutes . It started to roar within first 30 seconds.

Observations are -

1. A few small cracks develped around the feed tube, but none along the fire chamber or heat riser. The feed tube is made from high density fire bricks

2. I think the draft is sucking excess air, not sure though. Will it limit the attainable temperature in the fire chamber? The ten minutes test burn gave a little smoke in between feeding.


Any suggestions for further development and any issues comments with the structure as it stands are welcome. .

Hi Garry,

You are right. The test itself revealed that the heat riser isn't tall enough. I'm adding three layers of bricks to 4x height of the riser.

Do you reckon going slightly more than 4x will give better draft?

Hi folks.

I have started the construction of our food processing unit. Today we constructed the masonary J tube that will feed into a barrel oven on the top of it.

I used insulating fire brics for the burn chamber and heat riser. I have used hard fire bricks for the feed tube- so that the feeding of fuel doesn't wear out the bricks. The dimensions of the chambers throughout are 160 mm X 160 mm . So, the cross section area of the J tube is close to 40 sq inches.

Tomorrow I'm going to test fire it to see if the height of the heat riser is creating sufficient pull. I feel it will not require much change, but if the draft is found insufficient, I'll add one layer of bricks at the riser for increasing the height.

Keeping fingers crossed.

Thanks Rebecca.

I'm from Maharashtra, and it really is bright, sunny and dry most of the year here. Yes, the drying under the sun is very much a practice here. I was just thinking of speeding up the things using the residual heat from one process for another process. It's a thinking to take evry bit of useful heat out of burning the biomass.

So , dehydration is certainly not the process to use the residual heat. As of now, i am unable to find a way to put it to use. But I'll obviously keep reading and exploring .

Thanks all for responding

Haven't posted it. Will post here on my next visit to the factory.

Black oven all the way for me.

I have installed one for commercial use.  We roast paprika, tomatoes, potatoes , pumkins, eggplants to make smoked paprika, smoked tomatoes, pumkin pies,  roast potato mash, Baingan bharta etc.

That smokey flavour is the heart and soul of the food that we sell.

Thank you Garry,

Yes , I agree . While roasting tomatoes and pumpkin, a lot of moisture will get into the exhaust as you rightly pointed out. I think  I'll divide the project into two parts - 1. building a rocket oven for the puree product line. 2. Trials for dehyderation through exhaust - 2 find a way to transfer the recidual heat to another set up for dehyderation in some way. . Let's see if more inputs come so that the collective brainpower finds ways towards solution.

Regards
Kiran

Hi all,

I am Kiran Patil from India. I have been reading this topic for three four weeks now and got very valuable inputs. I decided to join this community as I found very cool discussions here.

Let me introduce myself first - I am a 43 yr who took early retirement from an automotive sector corporate job and now following my interest in food, farm and everything related to it as a lifestyle, and as a business too.

I belong to a farming family and we have a small farm in western India. We are planning to expand our farming business into a small food processing unit. I'm designing a rocket oven ( black type)  to produces smoked vegetable purees on my farm. We are planning to use farm waste biomass as a fuel to produce some smoking hot tomatoes and pumkin purees.

While we are at purees, I  was wondering if the exhaust of the rocket oven can be used for another product line of dehyderated smoked paprika, tomatoes etc.

Had anyone from the community tried to do this?
Is there any precedence to follow ?

( I'll post the progress of my project as I start building the rocket oven. And I'll be happy to share my experience and inputs as I gather them )

Thank you