• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    In the method for dewatering sewage sludge, high voltage pulses are introduced into a quantity of mechanically dewatered sewage sludge enclosed by a filter and at the same time the pressure is increased by introducing a displacement element into the sewage sludge located in the interior of the filter. The apparatus for this purpose comprises a filtration chamber, a filter arranged concentrically in it with an interior for receiving a quantity of sewage sludge, a displacement element which can be moved into the interior of the filter and a generator connected to the displacement element and the filter for generating high-voltage pulses.
    公开号:CH710311A2
    申请号:CH01652/14
    申请日:2014-10-28
    公开日:2016-04-29
    发明作者:Bernhard Wyss Felix
    申请人:Bernhard Wyss Felix；
    IPC主号:
    专利说明:

    The invention relates to a method for dewatering sewage sludge and a device for its implementation.
    Worldwide fall huge amounts of sewage sludge, which arises in the wastewater treatment by sedimentation. Sewage sludge contains polluting substances such as heavy metals, pathogens, hormones and other micropollutants. Therefore, the usual recycling or disposal options are increasingly limited or impossible. For example, the previously common application as fertilizer is already completely prohibited in many countries, but increasingly limited in other countries. Also sewage sludge landfills or co-incineration with household waste or as an addition in cement rotary kilns will be classified as problematic in the future. In the long term, only the burning of sewage sludge will be possible to ensure environmentally sound disposal.
    Experience shows that depending on the calorific value between 40 to 50% dry matter for an automatic combustion of sewage sludge (without additional fuel) are necessary. The smaller the calorific value of the dry substance, the better the sewage sludge must be dewatered to ensure self-contained combustion. The less developed an economy is, the smaller the calorific value of the dry matter of the sewage sludge.
    Well dewatered sludge has a calorific value that corresponds to that of dried lignite. In addition to the calorific value, sewage sludge also contains a considerable proportion of phosphorus in the ash, which can be recovered. For this reason, the co-incineration of dried sewage sludge in refuse incinerators or coal-fired power plants is banned in many countries, and more and more sewage sludge mono-incinerators are being built with energy and phosphorus recovery.
    In order to generate the required 40-50% dry matter, which would allow an automatic thermal utilization (combustion) with subsequent energy recovery, the methods known today are insufficient in several respects. Mechanical dewatering of sewage sludge is possible up to 30% dry substance (depending on the type of sludge), with special and expensive flocculants and chemicals, slightly higher values are possible depending on the sewage sludge. The cell structures contained in the sewage sludge contain bound cell water which, however, can not be removed by further mechanical measures. In order to achieve the necessary dry matter content for the self-combustion, further treatment measures, usually drying by supplying heat, are necessary. This increases the cost of disposing of the sewage sludge and worsens the energy balance.
    It is also known to suspend the sewage sludge high electric fields in order to break up the cell structures contained in sewage sludge and release the water.
    From DE 19 752 371 a method for the treatment of municipal sludges is known, in which high-voltage discharges are introduced into the sewage sludge in a reactor, which are killed in the sewage sludge cell structures and broken and the previously mechanically not separable water is released. The method is used for the pretreatment of sewage sludge for the purpose of conditioning before drainage and treatment of return sludge in biological sewage treatment plants.
    From US 5,893,979 a method is known in which in a continuous process already mechanically dewatered sewage sludge is exposed in a pressure vessel with integrated extrusion pulsed electrical high voltage discharges to break cell membranes and release previously not mechanically separable water. The dewatered sewage sludge is further processed via defined openings to solid particles (pellets).
    The invention has for its object to dewater sewage sludge with a simple and inexpensive method so far that a sufficiently high calorific value is achieved to allow an automatic combustion.
    According to the invention, this is achieved by a method having the characterizing features of claim 1 and by a device having the characterizing features of claim 5.
    In the following, a preferred embodiment of the invention will be described with reference to the accompanying schematic drawing.
    The drawing shows a device for dewatering sewage sludge with a cylindrical Filtrierkammer 6, in which a concentric cylindrical filter 1 is arranged. The filter is preferably a metallic or ceramic filter body (e.g., sintered filters or other pressure-resistant filter systems). A hollow cylindrical mandrel 2 is moved into and out of the filtering chamber by hydraulic cylinders 5 axially in the manner of a displacing member or piston. The mandrel 2 is referred to below as a multi-functional mandrel. An inlet valve 3 is arranged at the end of the mandrel remote from the filtration chamber, which controls the inlet of thin sludge (A) via the interior of the multifunction mandrel into the filtration space of the filtration chamber.
    At the opposite side of the multi-function mandrel Filtrierkammer an outlet valve 4 for dewatered sludge (B) is arranged. Also at the bottom of the filtration chamber is an outlet for the filtrate (C).
    A generator 7 for generating high voltage pulses is connected to the two valves 3 and 4. In the thin sludge inlet (A), an insulator 8 is mounted which during the high-voltage pulsation phase prevents the electrical conductivity via the thin sludge line (A). Furthermore, the system is electrically disconnected in the case of dewatered sludge discharge (B) and filtrate discharge (C), since the dewatered sludge and the filtrate run into an open system without a solid connection.
    At the upper end of the interior of the filter, a Austragsscheibe 9 is provided, which can be latched at the lower end of the multi-functional mandrel to discharge the dehydrated sludge through the open valve 4 after a completed dewatering cycle.
    The dewatering of thin sludge, i. not pretreated sewage sludge runs in the apparatus described above according to the following method: thin sludge is pressed by means of a pump via the open inlet valve 3 through the multi-function mandrel 2 into the interior of the filter 1. The fluid to be expelled enters the filtrate housing 6 through the filter and leaves the system via the filtrate outlet (C). In this process step, the multi-function mandrel 2 is in the upper part of the filter 1. Inside the filter, the sludge is greatly concentrated by running of the free water.
    Subsequently, the inlet valve 3 is closed, and the multi-function mandrel 2 is pressed by the hydraulic cylinder 5 in the interior of the filter 1. As a result, the pressure in the interior of the filter 1 is substantially increased and the sludge concentration in the interior of the filter is further increased in which further quantities of liquid are forced through the filter.
    As a result, the multi-functional mandrel is hydraulically retracted to the initial position, creating a cavity in the mud with the outer dimensions of the retracted multi-function mandrel in the middle of the filter. In this cavity, thin sludge is again supplied via the multi-functional mandrel 2 by means of pump pressure and pressurized. This is again a filtration, wherein the liquid is now pressed through the pressed sludge layer and the filter and then leaves the system through the Filtratauslass (C).
    The intercellular moisture trapped in the sewage sludge can not be squeezed out even when using high pressures. In order to break up the cell structures, the micro-millisecond-duration pulsed electric high-voltage discharges are supplied to the sludge via the multifunction mandrel during its immersion into the filter in a controlled manner via the inserted path (corresponding to the displaced volume) and the hydraulic pressure to be applied. In this case, a local surface evaporation of the trapped cell liquid takes place, which destroys the cell membranes, so that afterwards more liquid can be expelled. At the outlet valve, the voltage is dissipated. At this time, the voltage insulator 8 is activated at the time of thin sludge entry, i. the conductivity over the thin sludge line thus prevented. The high-voltage pulse generator 7 is designed such that, in accordance with the sludge properties, a defined number of pulses per unit time can be generated with an energy corresponding to the sludge properties and a voltage of> 10 kV. The required pulse frequency is thus regulated at constant pressure over the expected entry speed of the mandrel into the interior of the filter, i. the slower the multifunctional mandrel enters, the higher the number of pulses per unit of time must be. The pulse frequency, intensity (voltage level) and duration of the pulsation must be adapted to the Schlammigenschaft since it is always about only spend as much electrical energy necessary to allow an adequate mechanical drainage. These parameters must be determined empirically for each type of sludge. The system including the voltage generator is designed so that the necessary process parameters can be set and operated accordingly.
    With the implementation and the number of possible repetitions of the previous process steps (depending on the sludge property) lying in the interior of the filter mud is now sufficiently drained and can be ejected for further use. In this case, the multi-function mandrel is retracted to the starting position, then the Produktaustragsscheibe 9 is rotated relative to the multi-functional mandrel so that it locks positively on the front part of the multi-function mandrel. By opening the outlet valve 4, the multifunction mandrel with attached Produktaustragsscheibe eject the dehydrated sludge.
    The inventive method allows improved mechanical drainage, which makes a thermal drying of sewage sludge unnecessary. The energy required is less than 10% of the thermal energy which is used today, either via thermal post-drying and / or preheating the combustion air in the subsequent combustion stage. In any case, the invention allows a massive saving of energy and achieves a massive reduction in CO2 emissions.
    Experiments were carried out with a device according to the invention with an inner diameter of the filter of 70 mm and a multi-functional mandrel with an outer diameter of 50 mm and an immersion depth of 500 mm. With the described method, about 1 liter of water was displaced. Thus, sludge was dewatered from 27% to 55% dry matter, this under a pressure of 10 bar and about one hundred high-voltage pulses, each with 1000 joules, so a total of 100 000 joules. To thermally evaporate this amount of water about 2 250 000 joules are necessary. The solution according to the invention thus requires less than 5% of the thermal energy to be used.
    The device shown schematically in the drawing can be multiplied to an industrial size by similar to a tube bundle a plurality of filters and multi-functional mandrels is arranged in parallel. The multi-function mandrels are connected to each other at the entrance via a distribution channel. The necessary force for inserting the multi-function mandrels is accomplished by adequately dimensioned hydraulic units. The product discharge is achieved via a swing-down bottom plate which seals tightly when closed by means of a bayonet catch.
    权利要求:
    Claims (8)
    [1]
    1. A method for dewatering sewage sludge, characterized by introduction of electrical high voltage pulses in an enclosed by a filter amount of mechanically dewatered sewage sludge while increasing the pressure by introducing a displacement element in the interior of the filter sewage sludge.
    [2]
    2. Drainage method according to claim 1, characterized in that the high voltage pulses are delivered via the displacement element to the sewage sludge.
    [3]
    3. dewatering process according to claim 1, characterized in that the preceding mechanical dewatering in the interior of the filter by introducing the displacement element takes place without the introduction of electrical high voltage pulses.
    [4]
    4. dewatering process according to claim 1, characterized in that the introduction of the displacement element and the introduction of electrical high-voltage pulses takes place several times.
    [5]
    5. Apparatus for carrying out the method according to claims 1-2, characterized by a filtration chamber, a concentrically arranged in her filter with an interior for receiving a lot of sewage sludge, a retractable into the interior of the filter displacement element and one with the displacement element and the filter connected generator for generating high voltage pulses.
    [6]
    6. Apparatus according to claim 5, characterized by a displaceable on the displacement element Austragsscheibe for discharging the dewatered sewage sludge.
    [7]
    7. dewatering process according to claim 1-2, characterized in that the supply of the thin sludge takes place via the interior of the displacement element in the filtration space.
    [8]
    8. dewatering process according to claim 1-2, characterized in that the supply of the thin sludge takes place via another opening in the filtration space.
    类似技术:
    公开号 | 公开日 | 专利标题
    EP1875140B1|2012-06-13|Heat generator
    DE102004015226B3|2005-08-25|Plasma cleaning method suitable for interior surfaces of e.g. bulbs for discharge lamps, forms back pressure and ignites plasma only inside bulb
    EP0153972B1|1987-05-27|Method and apparatus for cleaning filter elements, especially for filter candles
    DE1919222B2|1976-05-20|PROCESS FOR SUPPRESSING SIDE DISCHARGES DURING ELECTROHYDRAULIC FORMING OF WORK PIECES
    DE4308390A1|1993-09-23|Electric charging, coagulation and filtering of particles suspended in fluid, e.g. air, water, oil, cleaning liq, working liq - arranging electric charging electrode in passage region through which fluid flows, electrode being made of conducting material
    DE102012107471A1|2014-05-22|Process and apparatus for purifying process water in a hydrothermal carbonation process
    CH634538A5|1983-02-15|METHOD FOR EXPRESSING CLEANERS, AND DEVICE FOR IMPLEMENTING THE METHOD.
    CH710311A2|2016-04-29|Method and apparatus for dewatering sludge.
    CH634604A5|1983-02-15|SYSTEM FOR PARTIAL TREATMENT OF LONG-STRETCHED WORKPIECES BY ELECTRICALLY POWERED GLIMMENT DISCHARGE.
    EP0027910A1|1981-05-06|Process for squeezing sewage sludges by means of a chamber filter press
    DE10040678C1|2002-05-29|Extraction device, used for high pressure extraction of abrasive material slurries, has feed line connected to feed device which extends over part of axial length of extraction container
    DE102015112270A1|2017-02-02|Apparatus and method for the extraction of flavorings from suspension in a fixed bed of plant flavorings
    EP0480176A1|1992-04-15|Process for dehydrating aqueous sludges by means of pressure
    DE2850825A1|1979-06-07|METHOD AND DEVICE FOR MECHANICAL DEWATERING OF PEAT
    DE102015210910B4|2020-11-19|Plant and method for separating an aqueous solution into purified water and residues of the solution
    EP3000516A1|2016-03-30|Method for cleaning solids by solvent extrationand shock wave treatment
    DE1461443B2|1973-03-08|FILTRATION METHODS, IN PARTICULAR DEWATERING OF SEWAGE SLUDGES
    DE2435799A1|1975-02-06|PROCESS AND DEVICE FOR THE CONTINUOUS IMPROVEMENT OF LIQUIDS OR SUSPENSIONS, WHICH MAY BE CARRIED OUT AT THE SAME TIME WITH CONTINUOUS ENRICHMENT
    DE7719666U1|1980-11-06|DEVICE FOR ADDING A LIQUID ADDITIVE TO A PUMPED MAIN LIQUID
    DE3027531C2|1982-05-19|Method and device for treating surfaces of parts, in particular the inner surfaces of plastic fuel tanks
    DE102018122517A1|2020-03-19|Process for the production of biochar by hydrothermal carbonization
    DE4141345A1|1993-06-17|Sewage sludge decontamination - forces sludge by centrifugal force against cathode wall, ionises heavy metals for deposition on anode
    DE372280C|1923-03-23|Method and device for digesting brown coal
    DE102016110866A1|2017-12-14|Ecological mulch, method and device for its production and its use
    DE1517705C3|1977-08-18|Process for dewatering sewage sludge
    同族专利:
    公开号 | 公开日
    CH710311B1|2019-04-15|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    2018-05-15| PCAR| Change of the address of the representative|Free format text: NEW ADDRESS: HOLEESTRASSE 87, 4054 BASEL (CH) |
    优先权:
    申请号 | 申请日 | 专利标题
    CH01652/14A|CH710311B1|2014-10-28|2014-10-28|Method and device for dewatering sewage sludge.|CH01652/14A| CH710311B1|2014-10-28|2014-10-28|Method and device for dewatering sewage sludge.|
    [返回顶部]