Gravity Fed or Hopper Feed Multi-Fuel Wood Pellet & Bituminous Coal

Stove, Boiler, Furnace, Fireplace, Burner

Inventor's Contact
E-mail: Tel No£º(86)13901185127 (China)

A burning element and its burner International Patent PCT/CN2009/001387

Principle Feature Benifit Difference Comparision Boiler Stove

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Type Wolf Tiger Elephant
Power 15kw or,
50,000 BTU
30Kw or
100,000 BTU
50kw, or
170,000 BTU
Fuel Bin 32 L or
50 bls
90 L or
130 bls
160 L, or
240 lbs
Flue 90mm or 3.5"
115 mm or 4.5" 150mm or 6"
Water 65 L or
17 Gals
115 L or
30 Gals
150 L, or
40 Gals
Material 6mm steel plate 6mm steel plate 6mm steel plate
Overal Size 40x40x125cm or
50x50x125cm or
60x60x125cm or
Weight 230kg or
510 lbs
280 kg or
625 lbs
340kg or
760 lbs
Price 6mm steel plate US$1000 US$1300 US$1700
Optional, made from stainless steel
Price 3mm
904 stainless steel
US$1200 US$1600 US$2100
Price 3mm
316L stainless steel
US$1800 US$2300 US$2900
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Type High Nickle High Chrome. Carbon Steel
Power 10Kw, or
35000 BTU
10Kw, or
35000 BTU
10Kw, or
35000 BTU
Fuel Bin 30L or
45 lbs
30L or
45 lbs
30L or
45 lbs
Flue 90mm or
90mm or
90mm or
Overal Size 25x25x125cm or
25x25x125cm or
25x25x125cm or
Material Stainless Steel 3mm 316L Stainless Steel 3mm 409 Carbon Steel Plate 6mm
Weight 50kg or 110bls 50kg or 110bls 90kg or 200 bls
Price ex-works US$950 ex-works US$600 ex-works US$550
Price of 20,000 BTU stove, can be sent via post office
Price 20,000BTU stove, 3mm 316L stainless steel US$750
Price 20,000BTU stove, 3mm 409 stainless steel US$450
the stove is very hot. a stainless steel protect net is optional at US$100.

If the boiler is placed outdoor, a layer of fiberglass and then stainless steel cover will be applied. Nice looking and heat insulated. If the boiler is placed indoor, high temperature paints will be applied. If you select stainless steel, the boiler looks neat and rust free
Blower is optional: the Blower is 0 to 10 watt adjustable, which is smaller than a common electrical bulb. Your car battery can run it full day. Blower helps falling down of ash to ash pan. If not blower you may need to hand shake ash every 3 hours depanding on height of flue and quality of pellet.

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Difference of my patent with other gravity fed stove or patents

I did search for American patent for Gravity Fed or Hopper Fed Stove. I did find 4 patents of it.But main problems are:
1.All pictures of fuel flow are "IMAGINARY". All patents can NOT control quantity of fuel being burned. When hopper is FULL, pressure is HIGH, more fuel flows to burning pot, and in turn big fire. When fuel level inside hopper is low, pressure is low, less fuel or no fuel flows to burning pot. In turn fire is small or dies. I read a BBS post, One guy has to put a heavy iron block inside the hopper to help the flow of fuel.
2. In these patents, fuel bin is BESIDE the burning pot, there is horizontal flow of fuel from fuel bin to bruning pot. Please note wood pellet and coal are NOT water, they can NOT flow easily.

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Benefit of my Patent:
1. Fuel bin is directly on top of burning element. Fuel only needs to DROP vertically by gravity. EASY.
2. Quantity of Fuel being burned is defined by size of burning element. true and reliable.
3.There are 2 burning elements, put them in vertical. Upper one has big gap of grate, and lower one has small gap of grate. You can burn mixed size of fuel efficiently.
4.It can burn wood pellet 1 to 3 days, NOT 8 hours. It can burn bituminous coal even better.

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Unique features:
1.Self-feed, can burn automatically 1 to 3 days
2.Simplest Design, No moving parts, High realiability
3.Multi-Fuel of Wood Pellet and Bituminous Coal
4.30% higher heat efficiency than hand fired coal stove
5.No auger conveyor, no jamming, low quality and in turn cheaper wood pellet
6.Better air tight design. Can easily be used in stove, furnace, boiler.

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Principle£º 1 stove body£¬2 fuel bin£¬3 burning element£¬4 hot air space£¬5 fresh air intake£¬6.flue£¬7.ash pan£¬21.cover.

open cover 21, ignating a piece of paper and charcoal in burning element 3, then put in fuel to fuel bin 2, close cover21. Fire takes place inside burning element 3. Ash falls down to ash pan 7 by gravity. As burning progresses, fuel inside burning element 3 is consuming, empty space is formed inside burning element 3. By gravity force fuel will fall from fuel bin 2 to burning element 3. In this way burning and refill is kept automatically.
size of burning element 3 and air intake 5 and flue 6 determine the strength of fire.
a 3 meter or 10 feet hight double layers stainless steel flue guarantees burning on.
a 3 to 10 watt DC blower will help burning more stable. In case clinker or bridge blocking inside fuel bin 2, a blower will help burning it down shortly.
Most wood pellet and Bituminous coal can burn automatically.The ash can drop down to ash pan automatically
Some wood pellet like cotton straw will form a tight ash ball, which can not drop to ash pan automatically. A blower will help to blow the ash to ash pan
Anthracite coal can not burn fully to ash, in turn can not drop to ash pan automatically. You need to shake the grate regularly, say every 4 hours. Even in this case it is better than handfired coal stove.
By adding blower, temperature sensor, and grate shaker, computer chips, the stove can be turned to real automatically stove or stoker.

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Comparision with Traditional hopper feed stove

This is a traditional hopper feed stove. Fire is determined by adjustable hopper plate. "buring coal" in this picture is not correct, it is nothing but an imaginary. In reality only a thin layer of coal next to grate is burning. The fresh air, flame, and hot air are flowing somewhat horizontal, they can not help ash to drop through grate. the coal directly on contact with the grate is always facing fresh air, or COLD air, it can not burn FULL to ash. My patent in contrary works this way, the flame, the hot air are flowing downward through the grate. They blow the ash through the grate to ash pan. aslo the coal directly on contact with the grate is always facing the hottest air or flame, it helps coal burning fully to ash.

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