FR2816614A1 - Gas content measuring and regulating system for compost or waste treatment platforms has measuring probes, suction pump and valves - Google Patents

Abstract

Gas content measuring and regulating system for compost or waste treatment platforms, is new. The system consists of a separate cabinet (4) containing one or more sensors (5) for measuring gases, especially oxygen or CO2, a gas suction pump (6). solenoid valves (8) operated by a programmed control unit (9), and tubes (11) connecting the valves to gas sampling probes (10) with strainers (15) on their tips, implanted in waste or compost heaps (14). Each of the probes corresponds to a single tube, and the valves connected to the suction pump allow air and gases from the probes to be drawn in successively and passed to the sensors. The oxygen sensor contains a zirconium oxide detector for a fast response time (under 6 seconds) which does not need recalibrating more than once in six months during normal operation.

Description

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 Piloting by controlled ventilation of the composting and waste treatment platforms.

 The present invention relates to an optimized device for regulating and measuring the content of oxygen or any other gas in composting or waste treatment platforms.

 The invention relates more particularly to a device for discontinuous measurement of the gas content, and in particular of oxygen, of the windrows of composts, green waste, fermentable waste or any other waste the gas content of which must be measured.

 In the context of the present invention, the term waste indifferently designates all of this waste.

 The measuring device is intended to make it possible to take the gas content at a waste treatment platform, and in particular composting platforms or platforms for cleaning up polluted soil; each swath forming a differentiated heap of waste or a single heap that can have a large area of several hundreds to several thousand square meters.

 The waste can be in particular of woody, fibrous, muddy or earthy nature, or even the whole indifferently.

 Waste treatment platforms, in particular composting and treatment of polluted soils, systematically use one or more probes for measuring the gas content and in particular the oxygen or C02 content with the sensor directly integrated into each probe. The probe then includes a sensor which sends the measurement signal through a transmitter directly to the programming system.

 The disadvantages of these measurement and regulation systems are numerous when the platforms are large and it is necessary to take the measurement of the gases and in particular of the oxygen, at the level of several swaths or at several places in the pile of waste.

 The sensors are sensitive elements, and there is an even greater risk that the equipment breaks down on site.

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There is not a single sensor but several measurement sensors making it possible to carry out the gas measurement in the waste pile.

 Measuring probes are expensive since each of them integrates a sensor, signal measurement and a device for transmitting the signal to the regulation.

 The integration of these different devices in the probe means that the sealing constraints on site must be controlled, in order to properly protect the electronic part of the sensors, from humidity and dust.

 The transmitted signal is electrical in nature, which means that the measuring probe must be connected to the regulation and its programming by an electric wire.

 In the case of platforms for composting or soil remediation, the use of waste turning devices promotes the tearing of electric wires, otherwise the breakage of the measurement probes and their sensors.

 The use of probes and in particular on-site oxygen probes requires regular and systematic calibration of all probes.

 The probe (s) must be supplied with electricity to operate.

 These drawbacks and these problems lead to high maintenance and upkeep costs, probe calibration, non-cleanliness when it comes to moving the probes, stopping operation of the processes when pulling out the electrical wires. of connection between the probes and the regulation.

 The object of the invention is to propose a measurement and regulation device which can overcome these drawbacks.

 The object of the invention is achieved by a device for measuring and regulating gases and in particular for measuring oxygen or C02, operating discontinuously. This device includes a remote control unit from the central regulation cabinet, comprising a regulation and programming automaton, regulation solenoid valves integrated or not in the programming automaton; one or more gas sampling rods and in particular of the oxygen or CO 2 content; in particular, for the measurement of the rate

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 oxygen in the waste pile, an oxygen sensor of the heated Zirconium oxide type; a single suction pump for gases and in particular oxygen; one or more rods making it possible to capture in depth the gases to be analyzed present in the air contained in the pile of waste, and in particular the oxygen content contained in the pile or piles of waste.

 The heated zirconium oxide sensors have a very short response time, of the order of a few seconds (less than ten seconds), and only require, as an interval to recalibrate the probe, a delay of the order of six months in normal operation.

 According to the invention, the device also comprises one or more canes for sampling gases and in particular oxygen. Each rod has a strainer inside which opens a plastic pipe which runs right through the rod.

 This hose allows the air and gas in the waste pile to be sucked in at this level. The plastic tube of each rod connects each rod to the control solenoid valves integrated in the remote cabinet. The rods are far from the remote cabinet.

 The air contained in the waste pile is sucked in thanks to the pump contained in the remote cabinet. The gas produced by the waste and contained in the air is therefore also sucked up to the remote cabinet where the gas content is analyzed (Zirconium probe for oxygen). The variation of the parameters linked to the gas triggers, as a function of the specific parameters linked to the process, a regulation making it possible to control and maintain the specific operating parameters of the platform, within given values (example of maintaining '' an oxygen level between two framework values, for a device for operating composting platforms by controlled ventilation using ventilation blowers).

 The device can be used, at the same time, to measure the content of one or more gases contained in the air and characterizing this heap or all the swaths forming the heap or the heaps of waste.

 The advantages of this device are numerous: - There is no longer any gas measurement sensor on the pile of waste and in the canes (no more gas measurement probe

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 on site, with sensor, and in particular in waste turning areas).

 - A single probe for measuring the gas content in the air for a given gas, such as oxygen or C02, and completely protected in the remote cabinet, making it possible to provide analyzes of the content of this gas, for an entire platform, and successively for each swath whose physicochemical characteristics are to be followed.

 - The probes are deleted. From now on, the gas is only taken from hollow canes immersed in the waste pile (s).

 - There is no longer a wired and electrical connection between the rod and the regulation, but a simple 45 plastic pipe used for the passage of the air and the gas or gases analyzed, at the level of the remote cabinet.

 Many rods can be installed, the cost of this material being very limited, compared to that which would consist in installing in each rod, a measurement sensor. And its transmitter.

 With a suitable PLC integrating PT 100 and PT 1000 inputs and outputs, it is now possible to also remove the transmitter usually fitted to temperature probes, for controlling the composting and pollution control platforms.

To obtain proper functioning of the device, a certain number of conditions must advantageously be met:
It is imperative that a strainer at the end of the rods immersed in the waste otherwise the plastic air supply pipe, may be blocked or clogged.

 Perfect sealing is required from the strainer to the solenoid valves integrated in the control cabinet or directly coupled to the programming machine; just as it is necessary that none of the plastic pipes are drilled, otherwise the air which will be sucked at the level of each rod, will not be that which must be

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 analyzed at the heart of the waste heap or of each waste heap, or of each swath.

 The pump installed in the remote cabinet must be of sufficient power to quickly suck in the air which is successively sucked in from each cane.

 The sensors for the measurement of gas in the sampled air must be sensitive enough to give a reliable and almost immediate measurement of the measured gas content.

 The gas analyzer must not take into account the gas content immediately aspirated and which stagnated in the plastic pipe, at the start of pumping, because this data is false and does not correspond to the value which must be measured. Only the value to be measured, is that obtained and corresponding to the air actually sucked out of the cane and not having stagnated in the plastic pipe.

 The cane must be long enough to measure the gas content in the heart of the waste pile.

 The programming automaton controlling the opening and closing of the solenoid valves making it possible to pump the air and the gases successively taken from each rod, must be efficient enough to control the openings and closings of the valves, the opening times and closings these valves, the time for a reading of the relevant signal; reading the signals supplied by the gas probe or by probes corresponding to other gases (example of oxygen probe or probe of C02) and the other measurement probes (example of temperature probes).

 If you want to remove the transmitters for temperature sensors, the programming automaton in the remote cabinet must integrate analog input cards PT 100 or PT 1000.

 To protect the following equipment (probe or probes with measurement sensors, the suction pump, the regulating and programming automaton and the regulating solenoid valves), it is necessary to place all of these materials in one or more cabinets deported. This or these remote cabinets can be separated from the central cabinet which can collect

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 the technical data provided by the measurement sensor (s).

 At the upper part of the hollow cane, a cable gland or a simple connection is sufficient to ensure the blocking and perfect sealing between the cane and the plastic air and gas suction pipe.

 The following description refers to Figures 1 to 4 which show a device for measuring the gas content present in the air present inside a pile of waste, according to two preferred embodiments of the invention.

 The installation comprises a central control cabinet (1) comprising the central control unit which can be coupled to a control PC or computer (2).

It also includes, connected by a Bus type link (3), to this central cabinet (1), a remote cabinet (4) containing one or more measurement probes (5) (one probe per type of gas analyzed); it also includes a gas suction pump (6) and an apparatus for regulating and regulating the air flow supplying the pump (7); it includes several solenoid valves (8) controlled by the programming automaton (9) (one solenoid valve per sampling rod (10)). Preferably, the gas suction pump (6) is equipped with an apparatus for regulating air flow to the probe (s), for example of the rotameter type.

 The suction pump (6) sucks the air successively contained in each of the rods (10) and necessarily passing through the plastic pipes (11) connecting the sampling rods (10) of gas to the solenoid valves (8).

 The suction pump (6) is directly connected to the probe (5) such as the oxygen probe, if not to the other gas measurement probes, by a supply pipe (11).

 The gas probe (s) (5) are directly connected by an electric cable (12) to the programming machine (9). The cable transmits the measurements obtained by each of the probes (5) to the programming automaton (9).

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 The programming machine (9) is directly connected to the solenoid valves by electrical cables (13) providing the electrical signal giving the order to open and close the solenoid valves (8).

 The gas is taken from the waste pile (s) (14) by means of a cane through which a plastic pipe (11) passes.

 Each plastic pipe (11) connects a sampling rod (10) to a solenoid valve (8).

 A rod (10) has a strainer (15) at its end and optionally a cable gland or a fitting (16) at each end of the tube (17) forming the rod (lao), and thus making it possible to keep the plastic pipe in the body of the cane.

 According to an embodiment represented by FIG. 2, the programming unit can include input and output cards directly integrating the solenoid valves and input and output cards of the PT 100 and PT 1000 (temperature) type making it possible to remove the transmitters usually fitted to each temperature probe.

 It goes without saying that the number of solenoid valves depends on the size of the platforms and the number of measurements desired for the analysis.

 It goes without saying that the remote cabinet can contain a single measurement probe for a single type of gas, just as it can contain several probes making it possible to analyze with the same device, several types of gas, present in the pile (s) of waste.

 According to a variant of the embodiments shown, the analysis equipment normally integrated in a single remote cabinet, can be integrated in one, two or more remote cabinets, depending on operating and process constraints.

 The present device has the following numerous advantages: - elimination of gas measurement sensors on piles of waste and integrated into rods; simplicity, reliability and economy of the device;

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1-facilité de remplacement des tuyaux plastiques en cas d'arrachement de ceux ci par les engins travaillant sur les plates-formes ; - réduction du nombre de capteurs et notamment de capteurs servant à la mesure de la teneur en oxygène ou en C02 pour le pilotage des plates-formes de compostage ou de traitement des déchets (un seul capteur sinon seulement deux ou trois capteurs peuvent suffire pour piloter des plates-formes de compostage de plusieurs dizaines de milliers de tonnes).

1-ease of replacement of the plastic pipes in the event of their being torn off by the machines working on the platforms; - reduction in the number of sensors and in particular of sensors used to measure the oxygen or C02 content for the control of composting or waste treatment platforms (a single sensor if not only two or three sensors can be enough to control composting platforms of several tens of thousands of tonnes).

 - possibility of having a single oxygen sensor to control and regulate a composting platform treating several thousand tonnes of green waste, sludge and fermentable waste, or polluted soil.

 - possible deletion of the temperature signal transmitter at each temperature probe.

 - possibility of having rods of a single standard model allowing to receive either the plastic air supply pipe or either a PT 100 or PT 1000 type probe, or any other type of sensor (humidity sensor).

 - the oxygen analysis probe in the case of a composting platform may no longer drift and therefore no longer be as regularly as in the past, recalibrated (recalibrated).

 - in this device, if a recalibration must nevertheless be carried out, it no longer concerns possibly only one probe, or even two or three oxygen probes only.

 The invention finds a whole series of preferred applications in the field of composting of all types of organic waste, and in particular green waste, sludge and fermentable waste, treated separately or mixed together.

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It also finds preferred applications in the field of treatment of polluted soils.

Claims (9)

 in particular, at least one oxygen or C02 measurement probe; a gas suction pump (6); solenoid valves (8) controlled by a programming automaton (9); a pipe (11) which connects each of the solenoid valves (8) to a gas sampling cane (10) which can be planted in the pile or piles of waste or compost; each of the sampling rods (10) corresponding to a single pipe comprising a strainer (15) for air intake; the solenoid valves (8) coupled to the pump (6) allowing successively the suction of the air and gases contained in the air at each cane (10) and the sending of this air and gases to the or the measurement probes (5).

 CLAIMS 1. Optimized device for regulating and discontinuous measurement of the content of oxygen or any other gas, in composting or waste treatment platforms, characterized in that the device comprises at least one remote cabinet (4) itself comprising one or more gas measurement probes (5) and, in  2. Device according to claim 1, characterized in that the remote cabinet (4) comprises the solenoid valves (8), each of these solenoid valves (8) being able to be connected to a sampling rod (10) by a supply pipe in air (11).  3. Device according to one of claims 1 to 2, characterized in that the solenoid valves (8) are separate from the programming machine (9) or are integrated directly into the programming machine (9).  4. Device according to one of claims 1 to 3, characterized in that it necessarily comprises at least one suction pump (6) and at least one probe (5) for measuring oxygen or C02.  5. Device according to one of claims 1 to 4, characterized in that a single gas measurement probe (5), in particular oxygen or C02, can allow the measurement of the content, respectively of oxygen or C02 , several swaths, thanks to the samples obtained from the different gas sampling rods (10). <Desc / Clms Page number 11>  6. Device according to one of claims 1 to 5, characterized in that the programming automat (9) comprises temperature probes and one or more input-outputs of the PT 100 or PT 1000 type.  7. Device according to one of claims 1 to 6, characterized in that the air sampling rod (10) in the waste, and used to measure the content of oxygen, C02 or any other gas, does not include no sensor or transmitter integrated into the body of the rod, but only a strainer (15) and an air supply pipe (11).  8. Device according to one of claims 1 to 7, characterized in that the gas suction pump (6) can be equipped with an apparatus for regulating the air flow (7) to the probe (s), of the rotameter type.  9. Device according to one of claims 1 to 8, characterized in that the oxygen measurement probe (5) must be capable of providing, in a very short response time, the measurement of the oxygen content of several swaths; and that this probe should therefore be with a heated zirconium oxide sensor, with a very short response time, of the order of a few seconds (less than ten seconds), and not requiring, as a probe calibration interval , that a delay of the order of six months in normal operation, to recalibrate the probe.