US4057401A — Methane gas process and apparatus

Claim 1

Independent Claim 184 words

Apparatus for the manufacture of methane gas comprising: a plurality of digester tanks arranged in series, first conduit means connecting said tanks for fluid flow between them, pump means to provide fluid flow through said first conduit means, agitator means for mixing liquid material contained within said tanks, a substantially air-tight enclosure surrounding said tanks, a solar heater to heat a stream of air passing through the heater, second conduit means connecting said enclosure with said solar heater for passage of a stream of air from said enclosure to said solar heater, third conduit means connecting said solar heater to said enclosure for passing a stream of air heated in said solar heater into said enclosure for indirect heat exchange with liquid material contained within said tanks, fourth conduit means connected to said enclosure to remove methane gas produced in said tanks therefrom, fifth conduit means connected to the last digester tank in said series to remove liquid material from said last tank, and sixth conduit means connected to the first digester tank in said series to introduce liquid material into said first tank.

Claim 2

Dependent Claim 184 words

Apparatus for the manufacture of methane gas comprising: a plurality of digester tanks arranged in series, first conduit means connecting said tanks for fluid flow between them, pump means to provide fluid flow through said first conduit means, agitator means for mixing liquid material contained within said tanks, a substantially air-tight enclosure surrounding said tanks, a solar heater to heat a stream of air passing through the heater, second conduit means connecting said enclosure with said solar heater for passage of a stream of air from said enclosure to said solar heater, third conduit means connecting said solar heater to said enclosure for passing a stream of air heated in said solar heater into said enclosure for indirect heat exchange with liquid material contained within said tanks, fourth conduit means connected to said enclosure to remove methane gas produced in said tanks therefrom, fifth conduit means connected to the last digester tank in said series to remove liquid material from said last tank, and sixth conduit means connected to the first digester tank in said series to introduce liquid material into said first tank.

Claim 3

Dependent Claim 105 words

The apparatus of claim 1 wherein said solar heater comprises a rectangular container comprising a bottom and four sides, a transparent panel coverning the top of said container, a rectangular section of black wire screen positioned in said container parallel to said transparent panel, a hinge attached to one edge of said container to permit it to be moved between a position of about 30° t0 80° of horizontal and an accordian pleated unit attached to the bottom of said container to provide a closed chamber beneath said container which can vary in size as the container is moved between said 30° to 80° positions.

Claim 4

Dependent Claim 175 words

In the method of producing methane gas by anaerobic digestion of a slurry of water material at a pH of between about 6 and 8 and a temperature between about 100° to 140° F wherein methane gas produced by bacterial action upon the heated slurry is collected and dewatered solid residue for use as fertilizer is obtained, the improvement which comprises exposing a metal screen to rays of the sun passing through a transparent panel spaced apart from said metal screen forming a first longitudinal passageway therebetween, said panel defining the sunward side of a gas-tight chamber, said chamber having a second longitudinal passageway substantially parallel to said first passageway defined by the shadow side of said metal screen and the spaced-apart back of said chamber, passing air through said first passageway, then through said second passageway, next passing the resulting heated air in indirect heat exchange with slurry undergoing anaerobic digestion and finally recycling said air to said first passageway for continuation of said procedure for heating of the digesting slurry using solar energy.

Claim 5

Dependent Claim 175 words

In the method of producing methane gas by anaerobic digestion of a slurry of water material at a pH of between about 6 and 8 and a temperature between about 100° to 140° F wherein methane gas produced by bacterial action upon the heated slurry is collected and dewatered solid residue for use as fertilizer is obtained, the improvement which comprises exposing a metal screen to rays of the sun passing through a transparent panel spaced apart from said metal screen forming a first longitudinal passageway therebetween, said panel defining the sunward side of a gas-tight chamber, said chamber having a second longitudinal passageway substantially parallel to said first passageway defined by the shadow side of said metal screen and the spaced-apart back of said chamber, passing air through said first passageway, then through said second passageway, next passing the resulting heated air in indirect heat exchange with slurry undergoing anaerobic digestion and finally recycling said air to said first passageway for continuation of said procedure for heating of the digesting slurry using solar energy.

Claim 6

Dependent Claim 24 words

The method of claim 3 wherein heat from combustion of methane gas produced by said method is employed to supplement said hot air heating.

Claim 7

Dependent Claim 13 words

The method of claim 3 wherein said organic waste material is sewage sludge.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1980-11-07	1981-05-09	1981-11-08	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1984-11-07	1985-05-09	1985-11-08	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1988-11-07	1989-05-09	1989-11-08	$7700.00	Window Closed / Lapsed

Methane gas process and apparatus

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