DD153811A1 - PROCESS FOR SELF-USE IN BIOLOGICAL PLANT EQUIPMENT - Google Patents

Abstract

The invention relates to a method for intensifying the Klaer and sludge processes by own energy utilization in biological Klaeranlagen, in which the sewage sludge during the sludge stabilization anzaellt. The aim of the invention is an improved Energieoekonomie Klaeranlagen while intensifying the Klaer and sludge processes by opening up the energy of the resulting fermentation gas and the unused Abwasserwaerme. The task is solved by using the resulting biogas in whole or in part to drive or heat pump, which opens up the energy of the wastewater without additional energy from the outside and the total energy thus obtained is fed to a separate hot water cycle. In addition to this, the heat released during operation of the heat pump drive unit can be tapped by suitable heat exchangers and used to further increase the temperature of the hot water obtained by the heat pump. The total energy obtained in the form of the hot water can e.g. for sludge heating in septic tanks, for heating sludge treatment sites, for heating purposes and in particular for heating the sludge regeneration tanks in the activated sludge process.

Description

Title of the invention

Process for self-energy utilization in biological wastewater treatment plants

Field of application of the invention

The invention relates to a method for intensifying the sewage and soak process by utilizing own energy in biological sewage treatment plants, in which biogas is produced as part of the sludge stabilization.

Characteristic of the known technical solutions In anaerobic stabilization of organic sewage sludge produced biogas, which due to its, high "methane content (> 60%) have a high heating ^\! Vert has _β Although currently a part of! Digester gas for healing within the treatment plant is used ( z * B _o Sludge heating in closed digesters _s System / building heating), in individual cases also offered for external use outside of the sewage treatment plantj However, to a large extent (depending on the season up to 60%) it is uselessly flared.

It is known that} digester gas is used auch.nach energy conversion Gasmotoreng gas turbines u.ä _e m, the driving machines.

In sewage treatment plants in the form der.fühlbaren heat of the waste water a second power source is available, "the wircU not normally accessible due to their low temperature consumed However, since in most wastewater around Ο is in households energy enfehal-

are not given a remarkable source of energy by the.

3o It is also known that the biodegradation processes are temperature-dependent, whereby a temperature increase accelerates the decomposition processes.

Due to the currently low degree of utilization of the development

35 baren and on the other hand the amount of energy required in sewage treatment plants essential intensification effects such as smaller reaction spaces, smaller area requirements, improved efficiency of the Kl ss process _s lower Energieeinsat ζ unused,

4o sources of information sum. State of the art

Ranclolf. R <

Author collective iv

Heinrich / Najork / Nestler

- Brandner

- Author collective

Sewerage and wastewater treatment Verlag für Bauwesen _s Berlin 197 ^

Teaching and Handbook of Wastewater Technology

Publisher W ₆ Ernst u _e Sohn ₉ Berlin / Munich 1978.:

Heat pumps for industry / agriculture and company publishing Verlag Technik Berlin 1978

The gas engine in use for? / Poor ~ pumping systems

OeI and gas firing 23 (Oct _e I978) 1o Page 533-5 ^ 5

Study on the possibilities of utilization of digester gas VEB projecting water management.

1979

Object of the invention

The aim of the invention is an improved .60 · energy economy of wastewater treatment plants with simultaneous intensification of the clarification and sludge process *

'-3-221 672

Presentation of the essence of the invention

The invention has as its object to develop the biological energy in treatment plants in the form of the Paul gas and the unused heat of the waste water so that

, the sewage and sludge processes material and. energy economy · »mixers are designed *

Erfindungsgeinäß the object is achieved _s that the resulting in the sludge stabilization digester gas with a notable by the high methane content calorific value. partially or completely a drive unit, ζ · Β. a gas engine ^ is supplied, which in turn directly drives the Yerdichtungsaggregat a gas heat pump, with an efficiency of about _{e e} 30%, based on the Ausgangsfaulgasenergie, can be achieved. The performance figures of the heat pump depend on the temperature gradient between the cold heat source (waste water) and the usable hot water. _Β At waste water temperatures from 8 ⁰ C to 20 ⁰ C, the performance figures are 4 to 6, provided that the hot water is heated to 3O ⁰ C to 5O ⁰ C and 2 to 4, when hot water with 40 ⁰ C to 80 ⁰ C is obtained. Thus, the • thermal efficiency depending on the wastewater temperature? and intended use of the hot water from 30% to 60% to 18o% increased * In addition, additional shares of the remaining approximately 70% igeh chemical ¹ energy of the digester gas are as heat energy is also closable * Approximately 25% of Gesamtariteils flows into the use of gas engines the

Cooling water of the gas engine, 35% contained in the exhaust gas and the rest are radiation losses _e of cooling water component whose usable temperature range in dependence varies from the motor type is between 75 ° C and 117 ° C "The% contained in the exhaust RME is energetically valuable kann.maxi- 'times to 25% are also used for heating purposes, "Thus, a total thermal efficiency of 110% to 23o% is achievable ο to the contrary, the biogas directly used on" heating of hot water _s may as a result of Kesse IwIrkuügsgrades maximum thermal W of 85% be achieved _e

'ti

Another effect is through the use of energy

1oo of the fermentation gas to drive the heat pump of the ever-increasing temperature of the waste water so much heat'entzogen, 'that unwanted Eutrophierungserscheinungen ~ as they arise at higher Abwassertemperaturen' - can be largely counteracted.

For the heat energy generated, in particular as hot water, there are a large number of sampling options inside and outside of sewage treatment plants. "In addition to the necessary heating of the septic tanks, buildings and. -maxed installations ₉ , the available heat surplus on

11p the intensification of biological processes, ζ _β Β _β heating of sludges requiring regeneration, are concentrated. "In the separate sludge regeneration, the absorption of the Schinutzstoff deposited on the Eelebtschlammfllocke takes place in a separate container _β As temperatures rise, the rate of degradation of BSBc AnteUe _{1 increases} which leads to a reduction of the pelvic voluffiina and consequently to a saving in building capacity. "In another example, there is the possibility of the hot water with temperatures between 30 ⁰ C to 50 ⁰ C through

12o heating coils similar to underfloor heating in the gravel area of sludge dewatering sites to lead and thus improve the drainage regime due to higher soil temperatures, resulting in a reduction of the complex space requirement and saving.an building capacity «

It is also possible to use the hot water content of the engine cooling water for the thermal sludge treatment by the method of pasteurization. This method allows a universal use of the sludge in agriculture., Is environmentally friendly and epidemically desirable hygienic Due to its high energy requirements, it has not been widely used,

The invention is explained below using an example:. ,

The accompanying drawing shows schematically the Faulbe 'holder'('I) in the ?, the Paulgas obtained, which is required to drive the gas engine (2). This gas engine (2) is coupled directly to the compressor unit (3) of the heat pump (4) and drives it. The clarified waste water in the secondary clarifier (5) is fed via a separate heat exchanger (6) _s "with the heat pump (4 ) is, it was withdrawn * It is transformed according to the principle of heat pumps to a higher temperature level in the form of hot water.This hot water is supplied to the heated cooling water of the gas engine (2) of a mixing device (7) and a combined warm water circulation offered to both the digester (1) and the sludge regeneration basin (8). "In both biological reaction basins, increasing the temperature regimen intensifies the reaction rates of the bacteria, thus reducing residence times and Saving on construction capacity The still usable exhaust heat can be converted directly or indirectly via conversion into hot water for heating - the Geb and enclosed facilities (9) are used *

Claims (2)

2 21 Invention claim 1 * Process for the exploitation of own energy in biological sewage treatment plants in which digester gas is produced in the context of sludge stabilization _9, characterized in that the temperature level is raised to intensify the sewage and sludge processes by partially or completely using the resulting digester gas to drive a heat pump, whereby on the one hand the by exploiting the energy of the wastewater by utilizing the gas from the digested sludge without additional energy from the outside gained total «own energy _s a separate _s the temperature increase of the sewage and sludge processes causing hot water circuit is fed, on the other hand the ge. • so much heat is removed from the treated wastewater that temperature-related eutrophication phenomena can be avoided «, 2 * method according to item 1, characterized in that to improve the energy economy released during operation of the drive unit heat, such as exhaust heat _s heated cooling water is opened by suitable heat exchanger and with the obtained by the heat pump hot water for further tempera. Door lift is mixed » 3e .The method of point 1 and 2, characterized in that the · gewonnene'Warmwasser preferably "vervjendet sludge process for heating sludge regeneration pool at what _s activated by rising 2 2167 Degradation rates at elevated temperature leads to a reduction in pelvic volumes. For this 1 page drawings