CA2122399A1 - Envirowaste conversion system - Google Patents

Abstract

This invention was developed by combining a series of technologies to work in concert to convert wastes to useful commodities. A vast improvement over just moving waste to different locations.

Combustible materials such as municipal garbage, tires, plastic, paper, etc. are converted to gases in a high temperature, oxygen starved oven, that has proven capable of burning without emitting smoke or unacceptable emissions. The gases are burned in high temperature after-burners creating energy that is used to generate electricity and heat. In other words co-generation using tires and garbage for fuel.

The Thermophilic Digester draws heat from the burner to create an ideal environment to enhance the production of enzymes. Electricity is supplied from the co-generation unit to operate the pumps, choppers and compressor. Air is injected in perforated pipes that are situated in the bottom of round horizontal tanks to provide oxygen for the bacterial function and convectively circulates the sludge without the need for mechanical paddles. This system reduces maintenance and operating costs.

The odours and gases generated by the digestors in the treatment process are drawn off and channelled into the oven and afterburners. The undigestible solids that remain are used as fertilizer. In the event they contain heavy metals as occurs in some areas these are recovered by dissolving said metals with sulphur dioxide in a closed circuit system and separating same by precipitation and filtration.

Description

MULTI TECHNOLOGIES WORKING IN CONCERT
TO ACHIEVE CONVERSION OF WASTE TO ~ A 2 1 2 ~ 3 ~ ~
USEFUL COMMODITIES

SPECIFICATIONS AND BACKGROUND OF THE INVENTION

The invention relates to the association of a series of l~ working in concert to convert wastes into usable products. The excessive build up of wastes that come in manV different forms has ~luylb~ increased to a serious status in the industrialized nations and to some extent in third world countries.

This , ~I,ed~ t~d dC.,.IIl ' ti ., of waste is the result of the u, rMI 1 ~ ,.r;. 1, of unique t ' 'c~ to create a better way of life. In the last 100 years individual transportation and the movement of goods changed from the horse and mule to motorized vehicles resulting in billions of tires being piled around cities and towns. They are unsightly, a fire hazard and breeding grounds for mosquitoes and rats.

The d~,~, 'r, of oil and gas to fuel mechanized transportation of people and goods has led to the d~,..' ",.,.,t of plastics and chemicals to such an extent that they are almost dominating our way of life.
Much of the products we use are made of plastic or packaged in plastic containers. They are not L;~d~,y~ ' " and eventually become waste in uM ' :aLh volumes.

In years past it seemed a simple matter to set up incinerators to burn waste without regard to the fact they emitted a great deal of smoke and toxic fumes. With the advent of plastics that give off toxic fumes and the increase in waste, air pollution became so unacceptable, burning had to be stopped. An alternate solution to burning was the creation of land fill sites to bury the waste. This so called solution has resulted in a new set of e.,K.~ ,.,.,t problems.

Most close-in sites were filled in a few years and the noxious gases being emitted have caused sickness and in some cases death to persons who lived on or near these sites. Pollution of the ground waters from these sites has become a concern also. Some cities have increased in size as much as ten times since World War 11. Thus the distances the garbage has to be hauled through traffic to reach the land fill sites has increased costs to the point where taxation to fund the handling of waste is putting a tremendous strain on the economies of b,.lu~lridli~d communities.

While the above problems were increasing with the growth of cities, immense sewage treatment plants and gathering systems had to be built. Many of these are now overloaded and inefficient. Their C A 2 ~ 2 2 3 9 9 design requires large lagoons to dewater the undigested solids occupying valuable land within a city. The noxious odors caused bV these lagoons are often carried over sections of the city they are serving.

Un li~ :~ " solids represent up to 10% of sewage by weight. This sludge was once thought to be good fertilizer to restore nutrients to the soil and increase food production. To the dismay of those responsible it was found the solid waste from sewage contained unacceptable levels of heavy metals that were being put back into the food chain causing health hazards. Mercury, lead, chromium, cadmium, cobalt, nickel, copper, platinates, silver, gold and other trace metals are present in various amounts most of which are injurious to humans when channeled into the food supply. This form of pollution had to be legislated against also.

The enormity of these problems requires a large army of workers and utilizes a ,u~uylt~ ly higher percentage of each tax dollar with no solution in site for most cities. Coping with waste has become so costly some cities have been forced to , u".;sx, ~",~;.1 . .:al standards at the risk of polluting thesoil, air, lakes, rivers, andlor ground water. Land fills were the only known alternative to hazardous tire piles until it was learned tires will not stay buried and on the surface they harbor mosquitoes and rodents. These with non ' ' ~ ~ ' " plastic blowing around and garbage piles that create obnoxious odors and swarms of flies are the realistic result of land fill sites.

This invention constitutes a combination of unique t~ull~uluy;~s that compliment and assist each other to provide a solution for the above problems.

DISCLOSURE - DETAILED DESCRIPTION OF THE INVENTION AND DRAWINGS

D~1). Figure 1 - Garbage andlor tires are fed into the Oven through Chute 2. Three doors or gates 3, 4, and 5 control the flow of materials into oven 6 and provide an air lock to prevent a flow of oxygen from entering the oven or smoke from exiting. Burner 7 ignites the waste materials with a direct flame created by a controlled flow of air from fan 8 to mix with propane or natural gas. This external source of fuel is shut - -down, except the pilot lights, as the conversion of solids to gases takes place. These gases provide more than enough fuel to maintain an oven temperature of 2000 F more or less. The entire internal surfaces of oven 6 and the horizontal burners 11 and 12 are lined with refractory to protect the outer shell from heat damage.

D(2). Approximately 20% of the gas generated is required to maintain the oven temlæld~ul~. An essential aspect of the technology is that the oven is constantly oxygen starved to prevent bonding of sulphur molecules with oxygen molecules, to avoid the production of sulphur dioxide. Sulphur molecules then elect an alternative by bonding with carbon molecules forming a non toxic alliance.

D(3). The controlled air flow into the oven to mix with the methane and other gases controls the oven . dlul ~. The sulphurous methane gases flow out through a port 9 in the top of the oven controlled by a damper 10 into the first of a pair of horizontal elongated tubes 11 and 12 referred to herein as d~ bU.ll~lo one positioned above the other. Air is blown from fan 14 into said tubes 11 & 12 through burner units 13 and 1 3A mounted in the end of each of the said horizontal tubes.

D(4). An igniter flames the propane or natural gas flowing through burner 13 to commence a burn of methane gases flowing out of oven 6 as it mixes with air blown into tube 11. Once this burn is started the outside gas whether it be propane or natural gas is shut down except to maintain the pilot light. This mix of air and gases in l~,.,,,~, dtUll,o Up to 2200 F s~hst~nti ll~ burns the smoke emitted from oven 6 which is unburned carbon particles floating in the air that becomes good fuel at high temperatures. The emissions from the burning in horizontal tube 11 flows into horizontal tube 1 2 where a second burner igniter 1 3A and air flow also from fan 14 assure the continued burning of the smoke and emitted gases.

Dl5). Ashes resulting from the conversion of solids to gases in oven 6 are discharged with a hyd,~ ' 'ly operated plunger 17 that pushes ashes out a rear door 18 into a water tank 1~. The hood 20 hangs down into the water to prevent oxygen from flowing into the oven when the ashes door is opened and to contain any steam or fumes that may occur when hot ashes are dropped into water.

~12~39q D(6). Figure 2 shows how the flow of heat from the oven and the two horizontal d~ bUll~ i is directed through a heat exchanger 21 to generate steam to turn a turbine 22 (Figure 2A) to power the generator 23 to produce electricity. The waste heat is then directed into the stack 24 which is installed on the exit of the heat exchanger 21. The heat created by burning the gases can be used directly for heating purposes as steam or heated air. The size of the oven and d~ltllbUII.~ can vary to -- n ' ~ various market demands.

D(7). Figure 3 is a Thermophilic Digester. A series of horizontal tanks 31 A, 31 B and 31 C are connected together allowing overflow from one to another. Food waste andlor sewage in a slurry is pumped by 30 through a chopper 32 and into tank 31 A that will in turn overflow into tank 31 B and then into tank 31 C.
One inch air lines 34, with fine perforated holes along their full length, are installed inside at the bottom of each horizontal tank and air is pumped into each tank with a compressor 33. Continuous circulation of the slurry results as aeration in the center creates the convective motion in the round horizontal tanks. - `

D(8). Electricity to power the pumps and r , r~SûlS iS drawn from the Generator 23, Figure 2A, developed by heat energy from the Oven (Figure 2). Heat is also drawn off the oven as required to assure that the t , dlul~ of the slurry in tanks 31A, B and C is an ideal c,..;,~ : for the rapid production of enzymes. This shortens the time factor by speeding up the decaying process, which is in reality an accelerated version of natures way of cleansing the earth. The 'is ' ' sludge is removed from tank 31 C by a sludge pump 35 and dried for market in drier 36. Due to the convective motion of the slurry in tanks 31 A, B and C most of the solids in 31 A and 31 B will flow into 31 C. Should there be a build up of sludge in tanks 31 A and 31 B, they are equipped with a drain valve to allow for an intermittent clean out, should it become necessary. --D(9). The unique aspect of the association of these n ' ~1 ~, - working in concert is that for the first time the problems ov~" whc'",;"g most cities namely the l~ d volume of municipal waste, tires, plastic, food stuffs and sewage can be resolved by this ~ r of Ir h"~l~J:- s without polluting land, air or waters. The tire piles, land fill sites and sewage plants with their obnoxious lagoons can be eliminated.

Combining these modified systems and enabling them to support each other constitutes a valid claim for a patent within the designated category of "Inventive Ingenuity". It is truly a unique ' of l~h ' ~ , that work in concert, to resolve the immense problems confronting civilization world wide.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

C(1). The claims made herein indicate that this inventive process is a practical and unique combination of proven systems working in concert that can solve the above complex problems economically and effectively.
The conversion of waste, into electricity and fertilizer whether it be tires, garbage, food waste or ordinary household garbage and sewage, without causing health hazards and/or doing environmental damage to air, water or land is clearly inventive ingenuity.

C(2). Waste management in the past could only be defined as the act of moving waste to less conspicuous locations and/or burying it. Responsible waste management is the conversion of these resources into useful commodities without polluting the environment.

C(3). This inventive process should be defined as an amalgamation of known technology with numerous improvements resulting in an all inclusive system to solve the entire waste problem of any town or city. The process actually goes beyond the no-damage aspect into a beneficial status by converting these wastes into energy and the production of non chemical fertilizer to enhance organic food supplies. Being able to achieve the above without injury to the environment is of vital importance and a primary aspect of the claims made herein.

C(4). This combination of processes working in concert can convert all the hard garbage, tires and plastic into heat and electricity in a smokeless oxygen starved oven while the food waste, wet garbage and sewage is digested by enzymes in a Thermophilic Digester leaving only a small percentage of sludge for fertilizer. In cases where heavy metals occur in the sludge these can be removed by applying a component part of the total process to purge the sludge by removing the base and precious metals and returning them to the industrial market. The solution is to burn sulphur in a closed circuit system and treat the solids with sulphur dioxide to solubilize heavy, toxic and noble metals which are then recovered from the liquor.

By adding a flocculent and normalizing the PH the metals are recovered by precipitation and filtration. The separated sludge solids form a desirable metal free fertilizer.

C(5). The ability to remove the heavy metals is a very important dimension of this inventive process as most sewage sludge carries unacceptable amounts of these metals. This combination of technologies offers a complete solution to the waste problems and is available. Land fill sites often referred to as the dump can be eliminated. This combination of processes is truly a conversion of garbage, sewage, tires, and plastic into useful commodities without polluting the air, water or land, and should truly be called the environments best friend.

C(6). The description and drawings attached hereto indicate why and how this combination of processes functions and its effectiveness and viability besides other benefits.

C(7). The initial segment of the process is a smokeless oven generating gases from tires, hard garbage, oil filters, magazines, and other combustible waste that are not readily digestible by bacteria but can be converted to fuel gas in intense heat. No smoke is emitted during the conversion. The abundance of carbon molecules in the oven bond with the toxic molecules to minimize their effect.. Heat and power produced by this segment of the process supply the operating needs of a companion segment, namely, the Thermophylic Digesters that provide an ideal environment to produce bacteria to digest food waste and sewage. It is important to note that any objectionable gases emitted by this operation are in turn consumed in the smokeless oven. In the smaller markets recovery of heavy and precious metals may be uneconomic. About 80% of the sludge would in these cases be converted to fuel gas in the Oven andconverted to electricity with the remaining 20% discharged as ash.

C(8). Maintaining the correct temperature and oxygen supply creates an ideal aerobic environment for enzymes to multiply. This shortens the time period necessary for the digestion of the food waste and sewage. Most of the water used in the Digesters can be recycled to conserve water and the enzyme base.
In cases where undigested solid sludge is produced in volume and heavy metals are present in unacceptable quantities another segment of the overall process referred to in par C(4) above can recover the metals rendering the sludge suitable for fertilizer. Sufficient quantities are necessary to make this phase economic.

C(9). This inventive process is a multicomponent unit each part of which is necessary to do a complete job. The segments compliment each other and work in concert to convert numerous forms of waste into heat or electricity and fertilizer. The key to the successful performance of these thechnologies to work efficiently in concert is an automated control unit developed over a period of years identified herein as an Auto - Teck Regulator System that adjusts to accomodate variations in both the feed rate and the B.T.U.
factors prevalent in municipal garbage and tire sizes.