Abstract: A method that includes conveying overheated dialysate through a cassette in a manner to reduce the temperature of the overheated dialysate, and a dialysis system including a control unit configured to cause overheated dialysate to be conveyed through a cassette in a manner to reduce the temperature of the overheated dialysate.

Abstract: Systems, methods and apparatus are provided for utilizing a substantially condensed phase cryogenic fluid for the purpose of remediation and retrieval of, e.g., spilled crude oil and other “oil spill”-related products from marine/aquatic and terrestrial environments. In some implementations, systems and apparatus are provided for applying a substantially condensed phase cryogenic fluid to a volume of spilled oil, and further having structure for collecting the spilled oil. Some implementations are environmentally-neutral. Substances other than oil may be remediated as well.

Abstract: Equipment for controlling blood flow in an extra-corporeal blood circuit, comprising at least a first sensor (11), de-signed to measure an arterial pressure (Part) upstream of a peristaltic pump (9); at least a second sensor (12), designed to measure an angular velocity (?) of the peristaltic pump; a memory (14) de-signed to store at least one set value (Qset) of the desired blood flow through the access branch, and a calibration function (F) in at least the variables (vI), related to the angular velocity (?) of the pump, (v2), related to the arterial pressure (Part) in the portion of the said access branch upstream of the peristaltic pump, (v3), related to an actual flow of blood (Qactual) through the said access branch; and at least one control unit (13), capable of calculating an actual flow value (Qactual) by applying the function F to the values of angular velocity and arterial pressure (Part, ?) measured by the sensors; comparing the actual flow (Qactual) with the desired flow (Qset); and varying the an

Abstract: A non-invasive device for measuring blood temperature in a circuit for the extracorporeal circulation of blood includes a line in which blood taken from a patient flows. The device also includes a temperature sensor connected to the line and provided with a device for measuring the intensity of an electromagnetic radiation. The measuring device faces a connecting portion or window of the line that is permeable by electromagnetic radiation in a first wave band, and generates a first signal, correlated with the electromagnetic radiation in the first band and therefore with the temperature of the blood flowing in the line.

Abstract: The present invention relates to a system for treating contaminated ballast water, comprising water inlets and outlets, piping connected to said inlets and outlets, at least one treatment unit connected to said piping, which treatment unit comprises UV radiation means, and catalysts, capable of, during operation, create photo-catalytic reactions in ballast water flowing through said unit, filter means for said ballast water and valve means for controlling the flow through said piping, treatment unit and filter means, characterised in control unit capable of, controlling and monitoring of said system for ensuring that no untreated water leaves the system in an uncontrolled manner.

Abstract: A reactor apparatus and method for removing chemical and biological contaminants from a contaminated fluid while minimizing disinfection by-products, sludges, and harmful residue. The reactor has a sequential, multi-stage, reaction vessel with an upper end region and a lower end region. The vessel has a liquid inlet port into which the contaminated fluid may pass. Treated liquid may exit the reactor through a liquid outlet port. A gas inlet port and a gas outlet port are provided. A plurality of stacked reaction chambers have a sieve tray and flange assembly, the sieve tray having holes up through which a gaseous phase may pass. A gas phase electrode, an electrical power supply capable of producing pulsed electrical discharges connected thereto, and a liquid phase electrode are provided. The electrodes create therebetween a pulsed corona discharge for generating reactive species in situ and destroying bacterial contaminants in the liquid.

Abstract: A system for load control in an electrical power system is described, wherein one or more temperature-monitoring devices are provided to control operation of a pool pump. When ambient temperatures are relatively high, and thus, electrical power demands from air conditioning systems are relatively high, the temperature-monitoring devices can remove power from the controlled device during the hottest portions of the day. The temperature-monitoring devices can provide power to the controlled devices during the cooler portions of the day. During heat waves or other periods of relatively continuous high heat, the temperature-monitoring devices can schedule power to the controlled devices to reduce overall power demands and to run the controlled devices during the cooler portions of the day when air conditioning electrical loads are reduced. The temperature-monitoring devices can also coordinate operation of the pool pump and a pool heater.

Abstract: A continuous flow multistage aerobic wastewater sludge treatment system and process comprising at least two stages connected in series, each stage comprising one or more covered tanks, tank segments or compartments, each having an enclosed separate gas headspace, wherein the gas headspaces of each stage are connected in a specified sequence that may be identical to or different from the staging sequence followed by the sludge liquid. An oxygen containing gas stream, such as air or an oxygen enriched gas stream, is supplied to the headspace of each stage, and a means for aerating the sludge in one or more of the tanks, tank segments or compartments is provided to enhance the transfer of oxygen from the gas headspace into the sludge liquid for use by bacteria in digestion of the sludge. At least one stage of the sludge digestion system is operated at a thermophilic temperature above 50° C.

Abstract: Heating systems and methods of preventing freeze-ups of underground tank systems. In septic underground tank systems, bacteria activity is enhanced by raising the temperature within the bacteria's environment. The preferred heater system includes a thermostatic control unit with a temperature sensor which may be selectively located to sense the temperature within a portion of the underground tank system. The heating systems and methods are particularly useful in mound or drainfield septic systems as well as underground water tanks.

Abstract: A method for submerging a submersible reservoir management system for large water reservoirs to circulate the water, monitor and add chemicals to the water and reduce temperature gradients. The method comprises locating a submersible Pump assembly in the reservoir, the assembly comprising one or more pumps, one or more jet mixers and a frame. The reservoir management system is analyzed for chemical content, and the submersible pump assembly adds disinfecting chemical when necessary to control water quality. A jet stream is produced to provide circulation of the chemicals and temperature uniformity within the reservoir. The reservoir management system can be repositioned both vertically and horizontally.

Abstract: A chemical treatment system that injects one or more dosage chemical solutions into a process. Conditions of the process are sensed by sensors, communicated to a chemical treatment management system. The chemical treatment management system processes the process conditions and issues command signals to one or more chemical storage systems to provide a dosage of chemical to the process. The chemical storage systems each comprise a chemical storage tank, a level sensor for the tank, a controller and a pump. The controller uses the command signals for varying in real time the dosage of the chemical solution by varying the pump operation. The chemical treatment management system also uses additional data from the chemical storage systems, such as tank level, and from other sources to provide the command signals and alerts/alarms and other user information.

Abstract: A filtering apparatus for purifying cooking oil is provided. The filtering apparatus comprises a housing, a filter housing including a filter and a first conduit in communication with a deep fryer for extraction of cooking oil requiring purifying from the deep fryer. The apparatus further comprises a pump for pumping cooking oil through the first conduit, a valve assembly in flow communication with the pump, and a second conduit in flow communication with the pump which transports cooking oil to the filter housing. The filtering apparatus also comprises one or more heating cables attached to the first and second conduits and located adjacent the pump and valve assembly, and a thermostat in communication with a thermostat probe attached to the first and second conduits and the valve assembly and pump, whereby use of the thermostat prevents activation of said one or more heating cables when activation is not required.

Abstract: A system and method are disclosed for purifying a waste fluid stream. The system includes a recirculation pump having an inlet for a recirculation stream and an outlet to expel a pressurized stream. The system includes a compressor having an inlet for an evaporation stream and an outlet for a pressurized evaporation stream. A primary heat exchanger has inlets for the pressurized stream and the pressurized evaporation stream, an internal surface area for heat transfer from the evaporation stream to the pressurized stream, and outlets for a cooled product stream and a heated pressurized stream. The heated pressurized stream is formed by heating the pressurized stream and the cooled product stream is formed by cooling the evaporation stream. The system includes an evaporation unit having an inlet for the heated pressurized stream and outlets for an evaporation stream and the recycled liquid bottoms stream.

Abstract: A method and system for providing Water for Injection using reverse osmosis. Water for Injection can be produced by reverse osmosis and the reverse osmosis membrane can be kept in a constantly self-sanitizing condition. One way of obtaining a constantly self-sanitizing condition is to maintain the reverse osmosis membrane at an elevated temperature during production of Water for Injection.

Abstract: A water distribution apparatus comprises a water user outlet facility and a water recirculation loop. The water re-circulation loop comprises a water supply, a water pump for establishing and maintaining a flow of water in the loop, a water delivery path extending from the pump to a water user outlet facility, a water return path extending from the water user outlet facility to the water supply, and a thermal disinfection apparatus disposed in the water delivery path for improving the potability of the water within the loop. A thermal heating apparatus and control is provided in the water delivery path or water storage tank to add thermal energy to prevent freezing of the stored water as well as the water flowing in the water re-circulation loop.

Abstract: The present invention relates to a method of controlling a dialysis apparatus, which can be used, e.g., for hemodialysis, hemodiafiltration, or hemofiltration. Numerous alarms occur during treatments creating additional workloads for the operator. The present method of controlling the apparatus allows an automatic switch from a first control mode to another, thus allowing the treatment to continue without operator influence.

Abstract: A system and method is described for destroying microbes in water from bathing apparatuses, such as swimming pools, using heat. Part of the stream from the pool is diverted, heated to an antimicrobial temperature, and recombined as a merged stream before it reenters the pool at a safe temperature. Further embodiments include addition of chemical antimicrobial agents, a controller, a storage vessel, and a cooler. Operating costs will increase little, if any, as compared with a conventional system.

Abstract: A method, system, apparatus and program for effecting the decomposition of organic waste material comprises: providing a treatment tank for decomposition of organic waste material, the treatment tank containing an active biomass comprising at least one bacteria that decomposes organic material; providing at least two inlets to the treatment tank, a first inlet comprising an inlet for organic material and a second inlet comprising an inlet for an aqueous stream; a processor that receives and stores information on: the status of chemical oxygen demand of the active biomass; and the oxygen provision capability of a first organic material that can be fed into the treatment tank through the first inlet; a mass flow control system controlled by the processor which feeds the at least one organic material through the first inlet at a rate based at least in part upon the status of chemical oxygen demand in the treatment tank as recognized by the processor.

Abstract: An integrated heating system for adding heat to a feed fuel within a module by way of an integrated heating element within the body or casing of the module. The heat may be selectively added to maintain a selected temperature.

Abstract: A method of operating an electronic device manufacturing system is provided which includes the steps of receiving information with an interface, wherein the information relates to an abatement system, and shutting down a process tool and an abatement tool in response to the information.

Abstract: An anti-foaming device (1) configured to reduce foaming of a fluid within a fluid reservoir (2, 3), the device including; a conduit (5) wherein the conduit (5) is in contact with at least a part of the exterior surface of the fluid reservoir (2, 3); a thermally conductive media wherein the media is past through the conduit (5); and, a heat transfer device; characterised in that the heat transfer device controls the temperature of the media within the conduit to hold the temperature of the fluid above or below a foaming temperature.

Abstract: A method and system of providing ultrapure water for semiconductor fabrication operations is provided. The ultrapure water is treated by utilizing a free radical scavenging system and a particulate removal system. The free radical scavenging system can utilize actinic radiation with a free radical precursor compound, such as ammonium persulfate. The particulate removal system can comprise one or more ultrafiltration apparatus. The ultrapure water may be further treated by utilizing ion exchange media and degasification apparatus. A control system can be utilized in feedforward or feedback mode to regulate addition of the precursor compound and the actinic radiation source, and to maintain a temperature of the ultrapure water product.

Abstract: The invention discloses a biotechnological process for the treatment of hydroxide sludge containing As produced in potable water production processes which use FeCI3 as a coagulant. The process seeks to modify the physicochemical properties of the produced sludge in such a way to facilitate the use of mechanical dehydration methods that allow decreasing the sludge volume and facilitating its final disposal.

Abstract: An improved method of altering a fluid-borne contaminant includes the steps of: providing a pump (21) having an inlet (22) and an outlet (23); connecting the pump inlet to a source (24) of contaminated fluid; operating the pump at a pressure ratio of at least 2.0 so as to sufficiently elevate the temperature of the fluid and contaminants passing through the pump, or, alternatively, operating the pump so that the outlet temperature of the fluid and contaminants passing therethrough is at least about 200° C.; and controlling the time during which the temperature of the fluid and contaminants are elevated; thereby to alter or convert substantially all of the contaminants passing through the pump.

Abstract: The invention relates to a device for purifying water, in particular for the continuous purification of water in the paper industry, said device comprising at least one supply line and at least one drain line for the water. The device also comprises a compression device for at least one sub-stream of the water, an injection device for injecting at least one gas and an expansion device for expanding at least one sub-stream of the water. In addition, the device comprises a unit for separating different phases of the water for purification. The device is characterized by a control system, which detects at least one parameter of the water and controls at least the addition of at least one additive in accordance with the process parameter.

Abstract: An apparatus and method of determining chemical dosage required to reduce sulfides in wastewater includes providing a headspace apart from the wastewater. The temperature of the wastewater and the concentration of sulfide gas in the headspace are measured. Dissolved hydrogen sulfide gas concentrations in the wastewater are calculated from the temperature of the wastewater and the concentration of sulfide gas in said headspace. When pH is monitored, dissolved sulfide concentrations can be calculated.

Abstract: An improved method of controlled energy delivery utilizing solid, liquid, and gaseous carbon dioxide (CO2) into a water well and the surrounding aquifer to remove deposited material which may cause loss of capacity in wells and a variety of water quality problems. After proper study and evaluation of problems associated with a well to be treated, adequate injection of the required amount of CO2 and energy is achieved by real-time monitoring during the injection and manipulating the phase changes in the CO2 that take place in the well and the aquifer.

Abstract: Continuous biowaste sterilization process, the operability of which is ensured in such a way that during process startup, extreme conditions possibly coming into question during operation are simulated, i.e. the greatest possible flow rate and the lowest temperature of the feed flow. In the startup stage, a liquid to be sterlized is circulated in the apparatus, until the capacity has been ascertained, whereafter the discharge stream can be conducted to a sewer system. The apparatus according to the invention comprises, in the flow direction of the biowaste-containing liquid, a storage tank, at least one feed pump capable of delivering a constant flow, at least one heating unit, at least one cooling unit, and a circulation circuit for circulating the biowaste-containing liquid through the heating unit, as well as connecting piping and valves. By means of specific piping and valve arrangements it is also ensured that all parts of the apparatus can be sterilized for maintenance purposes.

Abstract: An apparatus and method recycles the abrasive fluid or slurry effluent used in the polishing step in the manufacture of semiconductors. Agglomerations of abrasive grains built up in the slurry effluent are crushed using a mill, ultrasonic oscillation, or pressurized circulation. The slurry effluent is then regenerated and reused.

Abstract: An apparatus is adapted to centrifuge a container for separating a component, such as fibrin monomer, from blood or plasma. The container includes a cylindrical member, and a piston displaceable therein and a tubular piston rod, which extends through a top wall of the cylindrical member. The piston divides the cylindrical member into a first chamber positioned above the piston between the piston and the top wall, and a second chamber positioned below the piston. The apparatus includes a supporting turntable which releasably retains the cylindrical member. The supporting turntable is connected to a first activator for rotating the supporting turntable with the container about the central axis thereof. The apparatus also includes a rotatably journalled piston activating mechanism adapted to activate the piston by a second activator.

Abstract: New and in-use fire sprinkler systems can be sterilized by employing antimicrobial gases. The gases include steam, oxygen, and chlorine. Water added to the system after sterilization can be sterilized to prevent the reoccurrence of microbiological contamination.

Abstract: A monitoring system such as a septic tank monitoring system for distinguishing between and identifying the location of a sedimentary layer, a scum layer, and any intervening liquid zone in a septic tank with an elongate sensing probe for being disposed in the septic tank, a plurality of sensors disposed along the sensing probe, and a remote monitor operably associated with the plurality of sensors, such as thermistors, for providing a remote indication to a septic tank operator of the location of the sedimentary layer, the scum layer, and any intervening liquid zone in the septic tank based on the signals from the plurality of sensors so that a septic tank operator can monitor the contents and condition of the septic tank without a need for excavating and physically inspecting the septic tank.

Abstract: A method, system and apparatus for performing peritoneal dialysis are provided. To this end, in part, a method of controlling a medical fluid heater is provided. The method includes the steps of determining a first heater control output based on a number of measured inputs for the heater and at least one mathematical relationship between at least two of the measured inputs, determining a second heater control output based on at least one fuzzy logic membership function and at least one fuzzy logic rule, and determining a third heater control output based on the first and second outputs and using the third heater control output to control the heater.

Abstract: A computer-implemented process rates pipe segments in a water distribution system, the water distribution system including pipe segments and hydrants. Information gathered from maintenance tasks and inspections performed on the pipe segments and hydrants within the water distribution system is stored in an electronic database. The information in the electronic database is analyzed for a specified period of time to determine the presence of water quality factors and service interruption factors. Points are assigned to the pipe segments based on the presence of the water quality factors and service interruption factors. The pipe segments are rated based on the total points assigned to the pipe segments. The pipe segment ratings can be used for prioritizing the replacement of pipe segments in the water distribution system.

Abstract: The present invention relates to a method and apparatus for reducing the amount of hydrogen sulfide in the effluent of a water heater. A water heater of the present invention comprises an aeration device comprising a pump connected to a tube connected to an air sparging unit. The water heater may further comprise a programmable thermostat capable of controlling the temperature of the water in the water heater. The method of the present invention comprises the step of periodically or constantly passing a plurality of air bubbles through the water contained in a water heater. The method may further comprise the step of heating the water in the water heater.

Abstract: A system is provided for removing dissolved metals from industrial wastewater by electrocoagulation. The system includes an electrocoagulation reactor with a DC power supply having an insulation support enclosure with positive and negative electrode plates disposed thereon. The electrode plates are insulated for each other but remain in direct contact with the wastewater as it flows between the electrodes. The DC power supply induces opposite charges on alternate electrodes thereby generating an electric field between adjacent electrodes to cause the electrodes to ionize and go into solution for interaction with the contaminants in the wastewater as it flows through the reactor. The reactor is housed in a pressure vessel container so the exterior pressure on the reactor is higher than its internal pressure preventing leakage of fluids and oxygen and hydrogen gases produced in the reactor by decomposition of water.

Abstract: An arrangement for performing chromatography with a mobile phase and a chromatographic bed having a stationary phase is provided. The arrangement includes a support assembly configured to support the stationary phase. The support assembly has a sealed cavity configured so that when the support assembly is supporting the stationary phase a portion of the chromatographic bed and the stationary phase extends into the sealed cavity. The arrangement further includes a bladder having a void defined therein. The bladder is positioned within the sealed cavity. The arrangement also includes a fluid positioned within the void of the bladder so that the bladder is urged toward the stationary phase within the sealed cavity. The arrangement further includes an anode positioned in contact with the mobile phase.

Abstract: The invention comprises novel apparatuses and testing methods for evaluating a fluid diffusion component. The apparatus includes a fluid capable of undergoing oxidation or reduction, a half-cell electrode assembly able to receive the fluid, and a change in acidity indicator in communication with the assembly. An inventive method of the invention includes the steps of passing a fluid capable of undergoing oxidation or reduction through a half-cell electrode assembly to form a sample, contacting the sample with an indicator, and detecting a change in acidity in the indicator.

Abstract: A filtration assembly for filtering polymer fluids at varying flow rates includes at least two filter housing assemblies releasably attached to a filter support or main block. Polymer fluid is delivered to the filter housing assemblies via an inlet passage in the main block, and filtered polymer fluid is transported from the filter housing assemblies to an outlet passage in the main block. One end of each filter housing assembly is attached to the main block and includes an inlet port for receiving polymer fluid from the inlet passage and an outlet port for delivering filtered polymer fluid to the outlet passage. A single valve disposed on the main block selectively alternates fluid flow between the main block and each filter housing assembly.

Abstract: A system and method of desalinating brackish water from an inland, underground water supply is disclosed. The system includes a source of underground water, at least one distillation and/or non-distillation desalination stage, and a source of waste heat from a power generator. The method includes desalinating brackish water drawn from an underground source using waste heat from a power generator and one or more non-distillation and/or distillation desalination stages. Potable water is recovered from both the brackish underground water using waste heat from the power generator, while dissolved salts are taken to dryness and removed as solids and from the flue gases.

Abstract: An isotope separator includes a cylindrical chamber having first and second ends, and a length “L.” Inside the chamber, an E×B field is applied to produce plasma rotation. The energy in the plasma rotation is chosen to be much higher than the electron temperature which is clamped by radiation. As the plasma then transits the chamber through the length “L”, the electrons cool the thermal temperature of the isotope ions while maintaining the rotation. Under these conditions, the minority and majority isotopes become substantially separated from each other before they exit the chamber. To achieve this result, E×B is determined using mathematically derived expressions and, in compliance with these parameters, the length “L” of the chamber is determined so that the plasma residence time in the chamber, &tgr;1, will be greater than the cooling time, &tgr;2 (&tgr;1>&tgr;2) necessary to affect isotope separation.

Abstract: An oil circulation system that monitors filter life and can notify the operator of the oil filter life status. The oil filter life is calculated based upon oil pressure sensors on the inlet and outlet of the oil filter. Pressure drop, oil temperature, and engine speed from the tachometer are factored into an algorithm to calculate the percentage of oil filter life remaining. If the percentage is below the predetermined level, the system will warn the operator to change the filter. If the percentage is above the predetermined level, the system will record the extent of oil filter life remaining and repeat the process.

Abstract: A method, system and apparatus for performing peritoneal dialysis are provided. To this end, in part, a method of controlling a medical fluid heater is provided. The method includes the steps of determining a first heater control output based on a number of measured inputs for the heater and at least one mathematical relationship between at least two of the measured inputs, determining a second heater control output based on at least one fuzzy logic membership function and at least one fuzzy logic rule, and determining a third heater control output based on the first and second outputs and using the third heater control output to control the heater.

Abstract: A paraffin filter system (10) includes an in-line low-profile particulate filter (20) connected to a suction tube (14) which is used as an inlet to the paraffin filter system (10). A paraffin pump (54) pumps the melted paraffin from a paraffin spa (12) through the particulate filter (20) to a transfer container (11) via a discharge tube (22). A heater (78) is controlled by control logic (146) to operate in certain modes to melt any residual paraffin in the filter (20) and pump (54) before operation of the pump (54). The control logic (146) provides various modes of operation of the filter system (10) to assure that the system is ready to operate, irrespective of the operation of a control panel switch (6) by the user. When the paraffin is transferred back to the spa (12) from the transfer container (11), the melted paraffin is carried through a bacteria filter (21) in the filter system (10).

Abstract: This invention is directed to a method and apparatus for controlling and optimizing the feed of two or more oxidizers to an aqueous stream, thereby providing a synergistic effect. The system combines the use of amperometric or ORP based sensor technology with amperometric sensor technology employing a gas permeable membrane, thereby providing definitive control of each oxidizer feed stream.

Abstract: A method of treating industrial wastewater using casein includes an optimization step whereby treatment operating variable are optimized through statistical methods on experimental designs.

Abstract: The invention provides methods and an apparatus for more efficiently and economically producing purified water from sea water or some other salty or brackish water source. The efficiency is derived from the co-location with a power plant or other thermal generating source that will heat the feed water. Reverse osmosis membrane filtration systems work optimally when the feed water is at certain higher temperature, where that temperature is typically higher than the feed water at ambient temperatures. By using the heated sea water as the byproduct of the power plant electricity generating process and if necessary mixing it with ambient temperature sea water, if needed to lower the water temperature, and using this feed water with a higher temperature than ambient water temperature, the efficiency of the reverse osmosis system can be increased.

Abstract: A method for incubation of nitrifying bacteria in a high concentration which are contained in small amount in activated sludge includes subjecting the activated sludge to nitrification and acclimation culture for about one to two months using a sludge-treated waste liquid such as dehydrate sludge filtrate and digested eluate under such a condition that the dissolved oxygen is 2-4 mg/liter, the pH is 7.5-8.5 and the temperature is 25-35° C. and, at the same time, constantly maintaining the pH within the pH range of 7.7-8.5 by addition of an incubation promoter comprising a mixture of sodium carbonate and sodium hydrogen carbonate.

Abstract: A process for separating oily films from sand particles carried in a solvent free water stream includes the use of a jet pump scrubber in a density classification tank to treat such oily coated particles at controlled operating temperatures above 65° C. whereby, at such controlled temperature, enhanced cavitation in the jet pump separates the oily film from the sand particles to form slop oil, the tank providing for recirculation of the particles through the jet pump before discharge.

Abstract: The present invention pertains to a system for thermal disinfection of sludge with the aim of pathogen reduction. Such thermal sludge treatment systems require a certain minimum detention time t dependent on the temperature T of the heated sludge. The system according to the present invention is a continuous flow system. The system includes means for continuous sludge heating. The heated sludge flows continuously through at least one chamber, whereby the flow through the chamber has a substantially vertical direction. The mean residence time t2 of the sludge between entering the chamber and leaving the chamber is minimum 2 times the time period t required by regulations for conventional batch systems. The ratio of the flow path length of the flow through the chamber or chambers to the hydraulic diameter of the vertical flow through the chamber or chambers l/d is at least 3:1. The higher the ratio t2/t, the smaller can be the required ratio l/d. The relationship is: l/d*t2/t>8.