An adjustable refrigerant distribution device and a heat exchanger having same. The heat exchanger comprises: first and second collecting pipes; a heat exchanger core body; and a refrigerant distribution device, the refrigerant distribution device comprises a first distribution pipe, a first inlet pipe and a first drive assembly. The pipe wall of the first distribution pipe is provided with a first distribution hole. The first distribution pipe is inserted into at least one of the first and the second collecting pipes. The first inlet pipe is located outside at least one collecting pipe and is in communication with the first distribution pipe, and the first drive assembly drives the first distribution pipe to move relative to at least one collecting pipe. The distribution pipe of the refrigerant distribution device and the heat exchanger can translate along the axial direction, thereby adjusting refrigerant distribution so as to satisfy different distribution requirements.

Integrated heat spreaders having electromagnetically-formed features, and semiconductor packages incorporating such integrated heat spreaders, are described. In an example, an integrated heat spreader includes a top plate flattened using an electromagnetic forming process. Methods of manufacturing integrated heat spreaders having electromagnetically-formed features are also described.

In a cooled component system, a heat exchanger mounted on a surface of the industrial component is housed in an isolated access compartment adjacent to but separated from the primary compartment containing the industrial component. Housing the heat exchanger in a separately accessible compartment permits access to the heat exchanger for cleaning or other purposes without having to shut down the industrial component being cooled. A means for moving a cooling media over the surface a the heat exchanger might also be included to maximize heat exchange.

A rack airflow monitoring system is configured to measure airflow through an equipment rack having a housing and a perforated front door to enable air to flow into an interior of the housing. The system includes a control module, and a plurality of airflow sensors secured to the front door of the equipment rack and coupled to the control module. Each airflow sensor is configured to detect a parameter used to measure airflow and communicate detected parameters to the control module. The control module is configured to obtain temperature, airflow velocity, and airflow directionality from the plurality of airflow sensors at the front door of the equipment rack.

Embodiments of the invention provides a decoder for decoding a signal received through a transmission channel in a communication system, said signal carrying information symbols selected from a given alphabet and being associated with a signal vector, said transmission channel being represented by a channel matrix, wherein said decoder comprises: a sub-block division unit (301) configured to divide the received signal vector into a set of sub-vectors in correspondence with a division of a matrix related to said channel matrix;a candidate set estimation unit (305) for recursively determining candidate estimates of sub-blocks of the transmitted signal corresponding to said sub-vectors, each estimate of a given sub-block being determined from at least one candidate estimate of the previously processed sub-blocks,wherein said candidate set estimation unit is configured to determine a set of candidate estimates for at least one sub-block of the transmitted signal by applying at least one iteration of a decoding algorithm using the estimates determined for the previously processed sub-blocks, the number of candidate estimates determined for said sub-block being strictly inferior to the cardinal of the alphabet and superior or equal to two, the decoder further comprising a signal estimation unit (306) for calculating an estimate of the transmitted signal from said candidate estimates determined for said sub-blocks.

The present invention aims to provide a technology capable of enhancing the effect of reducing differential data in size. A bit shift unit shifts either of old data and new data in a forward direction and a backward direction of its bit string by each of 0, 1, 2, . . . , and n bit(s) to generate a plurality of data. A copy bit string extracting unit extracts information on copy bit strings based on the plurality of data and other non-shifted data. An additional bit string extracting unit excludes copy bit strings from the new data to extract information on additional bit strings. A differential data generating unit creates differential data based on the information on copy bit strings and the information on additional bit strings.

Methods and apparatus to parallelize data decompression are disclosed. An example method adjusting a first one of initial starting positions to determine a first adjusted starting position by decoding the bitstream starting at a training position in the bitstream, the decoding including traversing the bitstream from the training position as though first data located at the training position is a valid token; and merging, by executing an instruction with the processor, first decoded data generated by decoding a first segment of the compressed data bitstream starting from the first adjusted starting position with second decoded data generated by decoding a second segment of the compressed data bitstream, the decoding of the second segment starting from a second position in the compressed data bitstream and being performed in parallel with the decoding of the first segment, and the second segment preceding the first segment in the compressed data bitstream.

A switch-scanning circuit includes a chip and switching units. The chip includes pins having an output operation mode and an input operation mode, and a processing unit. The processing unit sets one of the pins as an input pin and the rest of the pins as output pins sequentially according to a clock signal, uses a scan signal to provide different voltages to the output pins, and then determines states of button switches according to a voltage of the input pin. The switching unit includes a power source resistance, switches and resistors. A first terminal and a second terminal of the power source resistance are electrically connected to a power source and a first pin respectively. The resistors have terminals electrically connected the first pin and terminals of the switches. The other terminals of the switches are connected to the pins other than the first pin.

A circuit includes a time delta detector configured to receive an input clock signal and a reference clock signal and generate a delta pulse signal and a reference pulse signal. A comparison circuit is configured to receive the delta pulse signal and the reference pulse signal. The comparison circuit generates an output indicative of a bit of a time difference between the input clock signal and the reference clock signal. A control circuit is configured to receive the output from the comparison circuit. The control circuit maintains a count of the time difference between the input clock signal and the reference clock signal.

The pulse width modulator includes a subtraction unit configured to perform subtraction between an m value digital signal and a pulse width modulation signal; a feedforward filter unit configured such that a ΔΣ modulator to which an output signal of the subtraction unit is input and which includes integrators of a second order or higher is in cascade connection, and configured to operate with a sampling frequency FS; a product-sum computing unit configured to operate with a sampling frequency (FS/n) (n: an integer of two or more) to perform product-sum computing of an output signal of each integrator of the feedforward filter unit; and a pulse width modulation unit configured to operate with the sampling frequency (FS/n) to perform pulse width modulation of an output signal of the product-sum computing unit to output a pulse width modulation signal.

A level shifter circuit includes a level shifting unit configured to receive signals that may vary in a first range via a positive input terminal and a negative input terminal, respectively and to output signals that may vary in a second range to a positive output terminal and a negative output terminal, respectively, where the second range is larger than the first range, a first pre-charging unit configured to pre-charge the positive output terminal to a predetermined level when a clock is in a first level, and a second pre-charging unit configured to pre-charge the negative output terminal to the predetermined level when the clock is in the first level.

A method for adaptively regulating a coding mode and a digital correction circuit thereof are provided. The method is for a successive-approximation-register analog-to-digital converter (SAR ADC). In the method, whether to regulate a binary weight corresponding to each of digital bits is determined according to the number of completed comparison cycles to provide a first coding sequence. The first coding sequence is directly compensated according to uncompleted comparison cycles to provide a correct digital output code.

Disclosed are an apparatus and method for compressing continuous data. The apparatus for compressing continuous data may include a data generator configured to calculate differences between adjacent values in original continuous data and generate data based on the calculated differences.

An encoder for encoding input data (D1) to generate corresponding encoded data (E2) includes data processing hardware which is operable: (a) to determine at least partial reoccurrences of data blocks or data packets within the input data (D1), wherein the data blocks or data packets include a plurality of bytes;(b) to employ at least one reference symbol to relate reoccurrences of mutually similar data blocks or data packets and/or to indicate whether or not there are reoccurrences of mutually similar data blocks or data packets within the input data (D1);(c) to employ a plurality of change symbols, for example a plurality of mask bits, to indicate changed and unchanged data elements of partial reoccurrences of data blocks or data packets within the input data (D1) and a change of data values of changed data elements; and(d) to encode the at least one reference symbol and the plurality of change symbols into the encoded data (E2). There are provided methods of using the encoder to encode input data (D1) to generate the corresponding encoded data (E2). Moreover, there are provided a corresponding decoder, and a corresponding method of decoding the encoded data (E2) to generate corresponding decoded data (D3).

Disclosed are methods and systems for significantly compressing sparse multidimensional ordered series data comprised of indexed data sets, wherein each data set comprises an index, a first variable and a second variable. The methods and systems are particularly suited for compression of data recorded in double precision floating point format.

An ultrasound device including an asynchronous successive approximation analog-to-digital converter and method are provided. The device includes at least one ultrasonic transducer, a plurality of asynchronous successive-approximation-register (SAR) analog-to-digital converters (ADC) coupled to the at least one ultrasonic transducer, at least one asynchronous SAR in the plurality having a sample and hold stage, a digital-to-analog converter (DAC), a comparator, and control circuitry, wherein a DAC update event following at least one bit conversion is synchronized to a corresponding DAC update event of at least one other ADC in the plurality of ADCs.

Methods and systems for time interleaved analog-to-digital converter timing mismatch calibration and compensation may include receiving an analog signal on a chip, converting the analog signal to a digital signal utilizing a time interleaved analog-to-digital-converter (ADC), and reducing a blocker signal that is generated by timing offsets in the time interleaved ADC by estimating complex coupling coefficients between a desired digital output signal and the blocker signal utilizing a decorrelation algorithm on frequencies within a desired frequency bandwidth. The decorrelation algorithm may comprise a symmetric adaptive decorrelation algorithm. The received analog signal may be generated by a calibration tone generator on the chip. An aliased signal may be summed with an output signal from a multiplier. The complex coupling coefficients may be determined utilizing the decorrelation algorithm on the summed signals. A multiplier may be configured to cancel the blocker signal utilizing the determined complex coupling coefficients.

A semiconductor device configured to perform an A/D conversion of a wide range of signals is provided. A semiconductor device includes: an input voltage detection unit configured to detect an analog input voltage; a reference voltage setting unit configured to set a reference voltage based on the detected input voltage; an amplifier configured to amplify a difference between the input voltage and the reference voltage; an ADC configured to perform an A/D conversion of an amplified signal; and an arithmetic processing unit configured to calculate a digital voltage corresponding to the input voltage based on a result of the A/D conversion and the reference voltage.

A current source device having a current source array includes a plurality of current source units, a plurality of least significant bits, and a plurality of most significant bits. The current source units are arranged along a plurality rows and columns of a current source array. Each of the least significant bits includes a first amount of current source units is placed at the geometric center of the current source array. Each of the most significant bits includes a second amount of current source units. The second amount is the first amount multiplied by a positive integer. The two adjacent bits in the most significant bits are centrally symmetrical to the geometric center.

An electronic apparatus and a method for detecting status of keys thereof are provided. The electronic apparatus comprises a key module, a key control circuit, a conversion circuit with calibration mechanism and a processor. The key control circuit detects whether any of keys in the key module is pressed. If the detection result is affirmative, the press status of each of the keys is scanned by the key control circuit to obtain a coarse scan result. The conversion circuit with calibration mechanism is configured to perform the other system function of the electronic apparatus. When the processor determines that at least one of the keys is not pressed according the coarse scan result, the conversion circuit with calibration mechanism is switched to assist a re-scan operation of the press status of the at least one of the keys.

For analog-to-digital converters (ADCs) which utilize a feedback digital-to-analog converter (DAC) for conversion, the final analog output can be affected or distorted by errors of the feedback DAC. A digital measurement technique can be implemented to determine timing mismatch error for the feedback DAC in a continuous-time delta-sigma modulator (CTDSM) or in a continuous-time pipeline modulator. The methodology utilizes cross-correlation of each DAC unit elements (UEs) output to the entire modulator output to measure its timing mismatch error respectively. Specifically, the timing mismatch error is estimated using a ratio based on a peak value and a value for the next tap in the cross-correlation function. The obtained errors can be stored in a look-up table and fully corrected in digital domain or analog domain.

For analog-to-digital converters (ADCs) which utilize a feedback digital-to-analog converter (DAC) for conversion, the final analog output can be affected or distorted by errors of the feedback DAC. A digital measurement technique can be implemented to determine switching mismatch error for the feedback DAC in a continuous-time delta-sigma modulator (CTDSM) or in a continuous-time pipeline modulator. The methodology forces each DAC unit elements (UEs) to switch a certain amount times and then use the modulator itself to measure the errors caused by those switching activities respectively. The obtained errors can be stored in a look-up table and fully corrected in digital domain or analog domain.

Modifying a digital data stream that includes immediately consecutive code words of different length by segmenting, based on a certain block grid, the digital data stream. Each block of the block grid includes a fixed number of bits. It is determined whether all bits of the last block associated with the digital data stream are occupied by data of the digital data stream. If not all bits of the last block are occupied, the unoccupied bits of the last block are padded with bits of an end-of-record (EOR) indicator. If all bits of the last block are occupied, attaching an EOR indicator to the digital data stream is skipped.

Continuous-time analog-to-digital converters (ADCs) such as continuous-time delta-sigma ADCs and continuous-time pipeline ADCs, has input resistor structure at the input. The input resistor structure is typically tunable, and the tunability is usually provided by metal-oxide semiconductor field effect transistor (MOSFET) switches. Core MOSFETs, which has a terminal-to-terminal voltage

An analog to digital converter includes an error integration circuit configured to receive an input charge from a detector and to integrate a difference between the input charge and one or more feedback charge pulses to create an error voltage. A quantizer is in operable communication with the error integration circuit and is responsive to the created error voltage. An accumulator having a mantissa component and a radix component is in operable communication with the quantizer. A charge feedback device in operable communication with the quantizer and the radix component of the accumulator. The charge feedback device is configured to generate the one or more feedback charge pulses proportional to the radix component of the accumulator and an output of the quantizer. Digital focal plane read out integrated circuits including the analog to digital converter are also disclosed.

For continuous-time multi-stage noise shaping analog to digital converters (CT MASH ADCs), quantization noise cancellation often requires estimation of transfer functions, e.g., a noise transfer function of the front end modulator. To estimate the noise transfer function, a dither signal can be injected in the front end modulator. However, it is not trivial how the dither signal can be injected, since the dither signal can potentially leak to the back end modulator and cause overall noise degradation. To address some of these issues, the dither signal is injected post the flash analog to digital converter (ADC) of the front end modulator. Furthermore, dummy comparator structures can be used to synchronize the dither with the quantization noise of the targeted flash ADC.

A circuit and a method for converting an analog signal to a digital value representation is disclosed. In one aspect, the circuit includes an incremental sigma-delta analog-to-digital converter (ADC). The circuit further includes a first input line for providing a primary analog signal representing a sensor measurement to the incremental sigma-delta ADC. The circuit further includes a second input line for providing a secondary analog signal to the incremental sigma-delta ADC. The incremental sigma-delta ADC receives the primary and secondary analog signals during a first period (TADC1) and a second period (TADC2), respectively. The circuit further includes a filter configured to weight the digital values in a sequence of digital values output by the incremental sigma-delta ADC, and to output a single digital value representing the sensor measurement.

System and methods for input path matching in pipelined continuous-time Analog-to Digital Converters (ADCs), including pipelined Continuous-Time Delta Sigma Modulator (CTDSM) based ADCs, includes an input delay circuit disposed in a continuous-time input path from an input of an analog input signal to a first summing circuit of the continuous-time ADC. At least one digital delay line is disposed between an output of an earlier stage sub-ADC (of a plurality of pipelined sub-ADCs) and a sub-digital-to-analog converter (DAC) that is coupled to the first summing circuit, and between the earlier stage sub-ADC and a digital noise cancellation filter. The digital delay line(s) is configured to enable calibration of delay of output of the earlier stage sub-ADC provided to the sub-DAC and the digital noise cancellation filter in accordance with process variations of the input delay match circuit to minimize residue output at first summing circuit.

A liquid separator system having a gas phase zone, an aqueous phase zone and a denser liquid zone is used to separate mixtures of fluids. The separator can be used for separating molten sulfur from liquid redox solution or reslurry water. The system includes a vessel with a top part and a bottom part. The vessel has a larger diameter at the top part than at the bottom part. The system also includes an inlet for introducing a redox solution or reslurry water and molten sulfur, which is denser than redox solution or reslurry water, into the vessel. An outlet near the bottom part of the vessel allows a flow of the molten sulfur from the vessel. An interface control structure senses an interface level between the redox solution or reslurry water and the molten sulfur, and the interface control structure controls the flow of molten sulfur from the outlet. The interface control structure is adjusted to optimally alter the vertical height of the interface level within the vessel so that the residence time of the molten sulfur in the vessel does not decrease as the sulfur production throughput decreases, and so that the interface area of the molten sulfur and the redox solution is reduced as the sulfur throughput decreases. A pressure controller monitors the pressure in the vessel and adds or removes gas from a gas phase zone in the vessel to maintain a predetermined pressure regardless of the vertical height of the interface.

Method for producing a uranium concentrate in the form of solid particles, by precipitation from a uranium-containing solution using a precipitating agent, in a vertical reactor comprising a base, a top, a central part, an upper part, and a lower part, the solid particles of the uranium concentrate forming a fluidized bed under the action of a rising liquid current which circulates from the base towards the top of the reactor successively passing through the lower part, the central part and the upper part of the reactor, and which is created by introducing a liquid recycling current (flow) at the base of the reactor, said liquid recycling current being tapped at a first determined level (A) in the upper part of the reactor and sent back without settling to the base of the reactor, excess liquid being also evacuated via an overflow located at a second determined level (B) in the upper part of the reactor; a method in which the upper limit (C) of the fluidized bed of solid particles is controlled so that it is positioned at a level below the first and second determined levels.

The present invention relates to means and methods for producing crystals or crystalline substances. In particular, crystals or crystalline substances which are useful as pharmaceutical ingredients can be manufactured.

A rotating knife is disclosed for disintegrating a crystal bed formed in a washing column for processing suspension of solid particles in a liquid. The rotating knife is provided with a spoke support. The spoke support comprises at least two spokes. The relative angle of the spokes is between approximately 20° and approximately 80°.

Disclosed herein is a method of fabricating a CIS or CIGS thin film, comprising: forming, on a substrate, a seed particle layer comprising copper-indium-compound seed particles comprising copper (Cu); indium (In); and at least one selected from the group consisting of gallium (Ga), sulfur (S) and selenium (Se),applying, on the seed particle layer, a water-soluble precursor solution comprising: a water-soluble copper (Cu) precursor;a water-soluble indium (In) precursor; andat least one selected from the group consisting of a water-soluble gallium (Ga) precursor, a water-soluble sulfur (S) precursor and a water-soluble selenium (Se) precursor, and forming a thin film at high temperature.

Method for the production of a coarse-grained ammonium sulphate product by crystallization and installation for carrying out the method from an ammonium sulphate solution in a DTB type crystallizer having an internal suspension circuit and a clarifying zone, from which a clarified partial flow of solution is constantly drawn off into an external circuit, is heated in a heat exchanger to dissolve the solids contained therein and is guided back as a clear solution into the lower region of the crystallizer. A fine crystal suspension flow is drawn off from the clarifying zone as a further partial flow and guided back into the internal circuit of the crystallization stage without any previous dissolution of the solid proportion contained therein.

A method of producing a titanium dioxide pigment is provided. Also provided is a method of improving the processability of titanium dioxide particles without adversely affecting the rheological properties of the titanium dioxide particles.

Mineral, cosmetic, pharmaceutical, agricultural, nutraceutical, and other compositions are produced using a mineral composition containing minimal concentrations of cadmium, lead, arsenic, and mercury and containing relatively high concentrations of micro and macro mineral elements, of rare earth elements, of calcium, and of silica. The mineral concentrations are produced by processing naturally occurring clay soil to concentrate mineral elements naturally occurring in the soil.

This invention relates to novel methods for affecting, controlling and/or directing various crystal formation, structure formation or phase formation/phase change reaction pathways or systems by exposing one or more components in a holoreaction system to at least one spectral energy pattern. In a first aspect of the invention, at least one spectral energy pattern can be applied to a crystallization reaction system. In a second aspect of the invention, at least one spectral energy conditioning pattern can be applied to a conditioning reaction system. The spectral energy conditioning pattern can, for example, be applied at a separate location from the reaction vessel (e.g., in a conditioning reaction vessel) or can be applied in (or to) the reaction vessel, but prior to other (or all) crystallization reaction system participants being introduced into the reaction vessel.

The present invention relates to compositions and methods to increase the output of a high quality product from the precipitation liquor crystallization process exemplified through the aluminum hydroxide recovery processes such as the Bayer process. The invention is a method of increasing the size of precipitates from a liquor. The invention in one embodiment relates to the use of a crystal growth modifier compositions added to the precipitation process to increase the particle size distribution of the precipitated alumina trihydrate.

Pelletizing device and method for pelletizing pelletizing materials having a pelletizing disk inclined to the horizontal and provided rotatable wherein the pelletizing disk is driven via a motor device. The pelletizing disk comprises a bottom and a side wall, the effective height of the side wall being variable. The side wall comprises an inner side wall device and an outer side wall device, the inner side wall device being disposed height-adjustable relative to the outer side wall device.

A method for making an agglomerate of an ore is disclosed. The method comprises contacting the ore with an acid solution and a stucco binder. The stucco binder may include calcium sulfate hemihydrate. The ore agglomerate may include ore, acid solution, and stucco-derived gypsum.

An object of the present invention is to provide a method for producing composite carbon fibers in which two or more carbon fibers are dispersed in a nearly homogenous state, the composite carbon fibers capable of being easily dispersed in a matrix such as a resin without leaving aggregate, and imparting low resistance. Disclosed is a method for producing composite carbon fibers, which comprises imparting a cavitation effect to slurry containing 6% by mass or less of two or more carbon fibers each having a different average fiber diameter under a pressure of 100 MPa or more and less than 245 MPa thereby to form a composite.

Titanium dioxide which includes particles having a large major-axis length in a large proportion and comprises columnar particles having a satisfactory particle size distribution. A titanium compound, an alkali metal compound, and an oxyphosphorus compound are heated/fired in the presence of titanium dioxide nucleus crystals having an aspect ratio of 2 or higher to grow the titanium dioxide nucleus crystals. Subsequently, a titanium compound, an alkali metal compound, and an oxyphosphorus compound are further added and heated/fired in the presence of the grown titanium dioxide nucleus crystals. Thus, titanium dioxide is produced which comprises columnar particles having a weight-average major-axis length of 7.0-15.0 μm and in which particles having a major-axis length of 10 μm or longer account for 15 wt. % or more of all the particles.

A device for taking up a silicon melt comprises at least one block of a refractory with a capillary structure.

In one embodiment, a method for producing a naturally purified salt product such as magnesium sulfate heptahydrate, wherein the salt mixture is treated with a solution comprising magnesium chloride; the first slurry is separated to provide a second slurry, which is further separated to yield a first liquid stream; the first liquid stream is crystallized to provide the naturally purified salt product. In another embodiment, a high purity salt product is produced. In another embodiment, other products that are produced include naturally purified sodium chloride and magnesium chloride.

Provided is a method and an apparatus for purifying potassium nitrate from the solid waste produced by a chemical glass-strengthening process. In the method, the solid waste is melted into a liquid waste at first. Potassium nitrate of various purity grades can be obtained by batch processing the liquid waste through stepwise cooling processes of cooling the liquid waste to a first temperature facilitating the potassium nitrate contained in the liquid waste to be crystallized at a first rate and then cooling the liquid waste to a second temperature close to the freezing point of the potassium nitrate at a second rate that is slower than the first rate. The recovered potassium nitrate from the solid waste can be recycled and reused.

The invention provides a method of agglomeration (10) which has the steps of mixing a feedstock (12) of small particles which have an average particle size of 3 mm or less with a binder (14) which is in the form of a polyvinyl alcohol in the form of an aqueous polyvinyl alcohol solution in a first blender (16) to form a binder mixture (18), reacting a gelling agent (20) with the feedstock and the binder and processing the binder mixture to deliver an agglomerate (22).

An object of the present invention is to provide a fine crystal particle production method and device that are excellent in mixing efficiency. This object is achieved by a method for producing fine crystal particles, comprising: a swirl flow producing step at which a swirl flow of liquid a comprising reactant A is supplied into a cylinder having a circumferential surface partially or wholly composed of a porous membrane; and a reaction step at which liquid b comprising reactant B which is reactive with the reactant A is supplied through the porous membrane to the swirl flow to effect mixing, whereby the reactants A and B are reacted to precipitate fine crystal particles.

Methods and apparatus for precipitating dissolved materials from a solution involve reduction of fines. In an embodiment, the method comprises: introducing a solution into a reactor, causing the dissolved materials in the solution to precipitate into crystals under a first reaction condition, adjusting the reaction condition from the first reaction condition to a second reaction condition, maintaining the reaction condition in the second reaction condition to cause a sub-population of the crystals to dissolve, and adjusting the reaction condition from the second reaction condition to the first reaction condition. In an embodiment, the apparatus comprises a reaction tank, a recycling path and at least an acid injector which is configured for dosing an acid into solution flow in the recycling path.

An application of carbon nanotubes on agglomerates of ore fines to increase the mechanical strength is provided. A process for the preparation of ore agglomerates having enhanced mechanical strength by the application of the carbon nanotubes is also provided.

The present invention provides a kiln for the combustion of agricultural waste. The kiln includes a central cylindrical combustion chamber. The central cylindrical combustion chamber includes a system for the control of combustion air to the combustion chamber. The kiln includes a second concentric cylinder surrounding the central cylindrical combustion chamber. The second concentric cylinder includes a system for the flow of cooling water through the first annulus between the central cylindrical combustion chamber and the second concentric cylinder. The kiln includes a system for the feeding of the agricultural waste into the central combustion chamber. The kiln includes a temperature sensing device to measure and display the temperature within the central combustion chamber during the combustion of the agricultural waste. The kiln includes a system for the recovery of ash from the kiln. In operation, the temperature of combustion is controlled to between 550° C. and 650° C. by a combination of increasing the supply of combustion air when the temperature in the central combustion chamber falls to near 550° C. and the introduction of cooling flowing water when the temperature in the central combustion chamber approaches 600° C.