Hydraulic and earth engineering – Subterranean waste disposal – containment – or treatment – With treatment of waste
Reexamination Certificate
1999-10-22
2001-08-21
Neuder, William (Department: 3673)
Hydraulic and earth engineering
Subterranean waste disposal, containment, or treatment
With treatment of waste
C405S128600, C237S059000
Reexamination Certificate
active
06276872
ABSTRACT:
BACKGROUND OF THE INVENTION
1) Field of the Invention
The field of this invention relates to impoundments and specifically to the removal of accumulated water from an impoundment.
2) Description of the Prior Art
The subject matter of the present invention will be discussed primarily in conjunction with a landfill. However it is considered to be within the scope of this invention that this invention could be utilized with other impoundments. As far as this invention is concerned, an impoundment is to include any material that is contained within an enclosure. Typical material could comprise a liquid, such as a brackish water, and also it can comprise leachate from a solid waste landfill. The enclosure frequently will be formed within a recess formed within soil. However, the enclosure could also be a non-soil enclosure such as a fabricated type of structure.
Within the United States, the incineration of solid waste is restricted due to the potential for creation of air pollution. Therefore, communities have selected the use of a landfill for disposal of solid waste. A landfill generally takes the form of a ravine so that the natural configuration of the terrain can be utilized to form a large container into which the solid waste is deposited. The bottom or floor of this ravine is covered with a thick plastic sheet. Liquids from within the solid waste will settle to the bottom and rainwater will also be passed through the solid waste to the bottom. The liquid that accumulates at the bottom is called leachate. Mounted within the landfill at the bottom is a leachate removing pipe. A typical leachate removing pipe is a length of pipe, generally a plastic pipe, that is basically porous as by including a mass of holes through its sidewall along its longitudinal length. The leachate is to be moved by a pump through the leachate pipe exteriorly of the landfill and deposited at an exterior location. This leachate is considered to be a waste material, and generally it requires the leachate to be transported to a liquid waste treatment and disposal facility that is designed for the disposal of hazardous liquid waste material. This may require the transporting of the leachate hundreds of miles and the application of expensive treatment procedures. Inherently, the treatment and disposal of leachate is an expensive procedure.
Although the leachate may contain numerous dissolved and suspended solids, the primary constituent in leachate is water. Water not only is released from the solid waste but also the landfill receives water from rain. The landfill and the surface impoundment in which leachate is frequently stored is subjected to evaporation due to heat from the sun. However, in wet climates, the annual precipitation will be greater than the amount of evaporation. Therefore, if something can be done to increase the evaporation rate within the surface impoundment, then a substantially lesser amount of leachate can result with this leachate being far more concentrated containing dissolved and suspended solid materials requiring the treatment and disposal of a substantially smaller volume of this leachate. If all of the water can be removed from the leachate, it may be suitable for disposal without additional treatment in the same landfill from where it was generated.
SUMMARY OF THE INVENTION
The subject matter of the present invention is directed to the inclusion of a closed heat pipe system within the surface impoundment with the closed heat pipe system to conduct heat into the liquid waste material contained in the surface impoundment. This will cause raising of the temperature of the liquid waste in the surface impoundment and thereby increase the evaporation rate of the water from the surface impoundment by as much as thirty times or more. The closed heat pipe system includes a heat transfer fluid with generally water being preferred. This heat transfer fluid is to be raised to a temperature of as much as one hundred seventy degrees Fahrenheit with this raising of the temperature being accomplished by solar collectors or other heat sources, such as the combustion of a fuel. The heat transfer fluid is then pumped through that portion of the closed heat pipe system that is submerged in the liquid waste contained within the surface impoundment so that the heat can be transferred to the liquid waste. A surface impoundment operated in conjunction with a closed heat pipe system in this manner is called a Low Temperature Heat-Assisted Evaporation Impoundment (LTHAI). An LTHAI can increase the evaporation rate of water by thirty times or more at an operating temperature that is well below the boiling point of water. In time, suspended solids accumulate in the leachate in the LTHAI as water evaporates and the solids precipitate to prevent the leachate from becoming supersaturated. The accumulated dissolved and suspended solids can be separated from the leachate in a conventional cooling crystallization process. The cooling crystallization process can be conducted exteriorly of the LTHAI or it can be conducted within the LTHAI by allowing the contents of the LTHAI to cool.
Without the application of external heat, surface impoundments are not practical in most of the United States because annual precipitation exceeds the annual evaporation from the surface impoundment. In an average year, the impoundment will gain water instead of losing water. This situation can be reversed by the heating of the liquid in the surface impoundment to increase the evaporation from the impoundment to thirty times or more than the rate from an unheated impoundment.
An advantage of the present invention is that the addition of heat to an impoundment is a technically simple procedure which can be constructed to operate unattended for extended periods of time thereby having a minimal labor expense.
Another advantage of the present invention is that the heated water utilized in conjunction with the closed heat pipe system is heated to a maximum temperature which is substantially below the boiling point of water which thereby reduces the chance of any maintenance individual incurring a severe burn from contacting the heated water or the closed heat pipe system.
Another advantage of the present invention is that a low-quality or low temperature heat source can be used to heat the heat transfer fluid in the closed heat pipe system. Such low-quality or low temperature heat sources are usually considered waste heat and have little or no value for other uses.
Another advantage of the present invention is that the heating of the surface impoundment is not to the temperature that would occur if the heating was accomplished by a boiling liquid evaporator. A boiling liquid evaporator accelerates the production and release of odorous compounds. Therefore, the evaporation system of the present invention reduces the creation of noxious odors which can prove to be, at the very least, undesirable and actually can present a health hazard to any individual that is in close proximity to the landfill.
REFERENCES:
patent: 4984594 (1991-01-01), Vinegar et al.
patent: 5261765 (1993-11-01), Nelson
patent: 5375539 (1994-12-01), Rippberger
patent: 5788412 (1998-08-01), Jatkar
patent: 5813799 (1998-09-01), Calcote et al.
patent: 5836718 (1998-11-01), Price
Das, Braja M., Principles of Geotechnical Engineering, Third Edition, PWS Publishing Company, pp. 596-599, 1994.
Envirosolve Corporation
Mayo Tara L.
Munro Jack C.
Neuder William
LandOfFree
Low temperature heat-assisted evaporation impoundment does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Low temperature heat-assisted evaporation impoundment, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Low temperature heat-assisted evaporation impoundment will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2537861