Abstract: An apparatus for supplying water containing dissolved gas comprising a flowmeter for measuring a flowrate of pure or ultra-pure water and a mechanism for controlling a flowrate, a means for adjusting an amount of water which adjusts an amount of the pure or ultra-pure water supplied to the apparatus for dissolving a gas, a tank which receives the water containing dissolved gas in an excessive amount which is not used at a point of use, a piping system through which the water containing dissolved gas glows from the tank towards the point of use and the water containing dissolved gas in an excessive amount returns to the tank, a piping system for supplying the water containing dissolved gas to the tank, and a controlling means for adjusting an amount of water based on a water level in the tank.

Abstract: A controller directs the operation of an air pollution control (APC) system having one or more controllable operating parameters and a defined operating limit representing a regulatory limit on an allowed amount of pollutant to be emitted by the APC system. An interface receives data representing a value of a regulatory credit available for emitting less of the pollutant than the regulatory limit on the allowed amount of pollutant. A control processor (i) determines a target set point for each of at least one of the one or more controllable operating parameters, which will maximize the regulatory credits earned, based on the received data and (ii) to directs control of each of the at least one controllable operating parameter based on the determined target set point for that parameter.

Abstract: A vacuum cleaner includes a motor-driven blower for drawing air and a dust-catching unit for separating dust from the air drawn by the blower and catching the dust separated from the air. A receptacle is located between the blower and the dust-catching unit and holds a filter for filtering the air that has passed through the dust-catching unit. An airflow control device is arranged between the filter and the blower. The airflow control device generates a first airflow, which passes through the dust-catching unit and the filter and goes toward the motor-driven blower. The airflow control device generates a second airflow, too, which bypasses the filter, passes through at least a part of the dust-catching unit, and goes toward the motor-driven blower. The part of the dust-catching unit is located downstream of the receptacle, with respect to a direction in which the second airflow goes.

Abstract: Methods for extracting and compressing an inert gas from an exhaust gas of an engine relate to providing an inert gas processing system including a multi-stage gas compressor to receive the exhaust gas from an exhaust gas processing system, a cooling and extraction system to receive the exhaust gas from each stage of the multi-stage gas compressor and remove liquids from the exhaust gas, and a controller to monitor operation of the inert gas processing system. The methods include processing the exhaust gas before each stage of the multi-stage gas compressor to clarify the inert gas in the exhaust gas, processing the exhaust gas after each stage of the multi-stage gas compressor to clarify the inert gas in the exhaust gas and compressing the inert gas processed for export from the inert gas processing system.

Abstract: A particulate trap has a plurality of filters and an air distributor. The air distributor has a first flow member and a second flow member. Each of the first and second flow members have a plurality of openings to allow exhaust flow through the plurality of filters. At least one of the first and second flow members is movable to selectively block exhaust flow to at least one of the plurality of filters at a given time.

Abstract: An apparatus for recycling the stripper solutions with higher recycling rate is disclosed. The apparatus includes a stripper condenser; a first buffer tank; a second buffer tank connecting to said stripper condenser by a first pipe and connecting to said first buffer tank by a second pipe; a recycling device connecting to said first buffer tank by a fourth pipe; a first pump mounted on said first pipe; a second pump mounted on said second pipe; a concentration detector mounted in said stripper condenser; and a controller electrically connected to said concentration detector, said flow meter, and said liquid level sensor for receiving the signals therefrom, and electrically connected to said first pump and said second pump for sending on-off messages to said second pump.

Abstract: A method and system for detecting and predicting air filter condition for an air handling system operates by determining a system resistance to air flow. The system resistance is utilized to determine a detection statistic indicative of current filter condition and to predict remaining life of the air filter. The system resistance is determined using models that approximate the expected operation of the air handling system. The approximation is then compared to actual values to obtain a difference. Once the difference between the approximated value exceeds a threshold value, an alarm is initiated that is indicative of system resistance. The remaining air filter life is then determined by using historically gathered data, or by using a known degradation rate of the air filter. Once the remaining life of the air filter is estimated, replacement can be scheduled that would coincide with other maintenance.

Abstract: A method and mobile system for cleaning dirty gas from a newly stimulated gas well. The entire system is supported on a trailer or other mobile support so that it can be driven from well site to well site for short-term, post-stimulation use only. The system comprises a gas separator, such as a membrane separator. The system also includes a pretreatment assembly for preparing the gas for the gas separator. The pretreatment assembly may include separators, a heater, a guard vessel and a polishing filter. A chiller or heat exchanger cools the treated gas to a marketable temperature. A generator and a hydraulics plant provide power to the system. Each mobile system will be designed to treat gases with widely different operating conditions varying from well to well.

Abstract: An apparatus for removing constituents from a fluid stream is provided. The apparatus includes a duct, a collection device, a sorbent injector, and an acoustic generator. The duct has a fluid passageway to receive a fluid stream having constituents. The collection device filters the fluid stream. The sorbent injector injects a sorbent in the fluid passageway of the duct. The acoustic generator generates an acoustic field in the fluid passageway of the duct to promote sorption of the constituents for collection by the collection device. Additionally, a method is provided for removing constituents from a fluid stream.

Abstract: A filter assembly is disclosed for use in connection with the filtration of products transported via pipelines, including high pressure gas pipelines. The disclosed filter assembly is comprised of a plurality of filter modules, a series of valves, inlet and outlet ports, connective piping, and spool pieces. The filter assembly will temporarily redirect flow from the pipeline, through one or more filter assemblies, and back into the original pipeline a short distance downstream from the original takeout point. If flanged connections are not readily available for a particular section of pipeline, the filter assembly can be connected to virtually any section of pipe through “hot tapping” technology, which allows a valve to be placed on an active and pressurized section of pipeline.

Abstract: An exhaust gas aftertreatment filter system for an internal combustion engine includes an aftertreatment filter disposed in-line with an exhaust gas conduit coupled to an internal combustion engine, a mounting bracket defining a mounting surface and at least one leg extending from the mounting bracket, the at least one leg defining a mounting foot at a distal end thereof with the mounting foot of the at least one leg and the mounting surface of the mounting bracket defining a first air gap therebetween, the mounting foot of the at least one leg secured to the aftertreatment filter, and at least one electrical component secured to the mounting surface of the mounting bracket.

Abstract: A process for controlling the volume of dry air, dried to a predetermined degree of dryness, from a sweep manifold of an air dryer system, flowing over a plurality of gas/liquid fluid separating membranes, comprising: diverting a predetermined volume of dried air to the manifold; sensing one of the flow volume and humidity values of the remainder of the dried air or the pressure differential within the system; and utilizing one of the differential pressure to control the predetermined volume of dried air and utilizing a controller for achieving the predetermined degree of dryness by controlling at least one solenoid valve which, in turn, controls the flow volume of the predetermined volume of dried air diverted to the manifold.

Abstract: A map which defines a relationship of an exhaust gas pressure P2 at the outlet of a filter (13) to a load Q and rotation speed Ne of an engine (1) is prepared, and an exhaust gas pressure P1 at the inlet to the filter (13) is determined from a differential pressure ?P between the front and rear of the filter and the outlet pressure P2 obtained by referring to the map. The inlet pressure P1 determined in this manner is used to determine an exhaust gas volumetric flow rate Q1, and thus an accurate particulate accumulation SM, which is required to determine the need for regeneration of the filter (13), can be calculated.

Abstract: An engine exhaust gas purification device is disclosed. The purification device has a filter (13) which traps particulate matter contained in the exhaust gas from an engine; a differential pressure detection sensor (16) which detects a differential pressure of the filter; a sensor (14, 15, 21, 31, 33) which detects an engine running state, and a microcomputer (22). The microcomputer (22) is programmed to compute an estimated ash amount ASH_a of the filter based on the detected differential pressure; compute an oil consumption amount OC_total based on the detected engine running state; compute an ash density DENS_ASH from the oil consumption amount OC_total and estimated ash amount ASH_a, and compute an ash amount ASH of the filter based on the oil consumption amount OC_total and ash density DENS_ASH.

Abstract: A control unit for controlling operation of a fuel-fired burner includes a housing having an air inlet which is open to an interior chamber of the housing. An air pump is positioned in the interior chamber of the housing and has an air inlet which is open to the interior chamber of the housing. The air pump generates reduced air pressure in the interior chamber which draws air into the housing and into the pump's inlet. This flow of air cools an electronic controller along with other components position in the housing. The air pump may be operated to draw air from the interior chamber of the housing and supplies the air to a combustion chamber of the fuel-fired burner to facilitate operation of the burner. An associated method of advancing air to a fuel-fired burner is also disclosed.

Abstract: A regenerable filter system includes a flow path along which a stream of fluid flows between an inlet and an outlet. A first filtering unit is located in the flow path. The first filter unit includes first and second regenerable filter beds, wherein each bed has a first adsorbent for removing a first contaminant from the fluid stream. A first valve is located between the inlet and the first and second filter beds for selectively directing the fluid stream through one of the first and the second filter beds. The other of the first and second filter beds is removed from the flow path. A second filtering unit is located in the flow path between the first filtering unit and the outlet. The second filtering unit includes third and fourth regenerable filter beds for removing a second contaminant from the stream of fluid.

Abstract: A process and system for purifying an impure gas to produce a purified gas in a gas purification system and protecting the system from damage by a) passing a portion of a first gas stream into a reactor vessel, which exits as a second purified gas stream; b) combining a portion of the second purified gas stream with another portion of the first gas stream to form a combined gas stream; and c) passing the combined gas stream into a sensing device to regulate the flow of the first and second gas streams into the reactor vessel.

Abstract: A method of controlling a gas adsorption apparatus including a sieve bed containing molecular sieve bed material, the bed being cyclically operable in a charge mode to adsorb non-product gas from an air supply thereby to increase the concentration of a product gas in a product gas supply which passes to a product gas line and in a vent mode to desorb the adsorbed non-product gas which passes to a non-product gas line, and there being a passage to permit a restricted amount only of the product gas supply to pass from the product gas supply line to the bed when operating in vent mode, and wherein the method includes operating a variable flow device to permit an increased amount of the product gas supply to pass to the bed when operating in vent mode, under predetermined conditions.

Abstract: The invention concerns a device and method for monitoring the integrity of filtering installations consisting of a filter housing (1) designed to perform integrity tests and for filtration, equipped with a plurality of filter elements (2, 3) and an electronic testing and monitoring unit (4) designed for monitoring and performing integrity tests, said filter elements (2, 3) having each a storage element and a communicating part (7) being connected to the monitoring and testing unit arranged in the filtering housing, whereon data of said electronic storage elements can be read.

Abstract: A trap device including at least one substance delivery element for introducing a substance therein is disclosed. The delivered substance may influence the nature of deposits that have formed within the trap device, may influence the formation of deposits within the trap device, or may cause a precipitate to form. Deposit interaction elements may be employed to influence the distribution or redistribution of deposits within the trap device. Deposit interaction elements may effect thermal conditions, introduce substances, or physically interact with deposits within the trap device. Further, a storage region within the trap device may be used to accumulate deposits. In one embodiment, a substantially continuous path through the trap device may be maintained or preserved so that deposits form within the trap device except substantially along the path. The present invention also encompasses a method of operation of a trap device as well as a system incorporating same.

Abstract: An apparatus for separating and converting exhaust particulates from a stream of exhaust gas, especially a diesel engine, into gaseous substances, in which the exhaust gas is guided through a honeycomb filter (6) made from a porous ceramic material whose axially extending channels (1, 2) are open merely at one face side of the filter and are closed off at the respective other face side, and a voltage is applied to electrodes (3, 4) extending parallel to the channels (1, 2) of the honeycomb filter (6). The closure of the channels (1, 2) at the face side is made in such a way that the channels (1, 2) each extending at the same normal distance from one of the electrodes (3, 4) are either all open or all closed off at their face side (9). The channels (1, 2) are mutually offset in a brickwork-like way.

Abstract: A method of operating a fuel-fired burner of an emission abatement assembly includes supplying a reduced amount of fuel to the fuel-fired burner in response to detection of a burner shutdown request. Such a reduced fuel supply continues for a predetermined time period after which fuel is no longer supplied to the burner. The supply of both combustion air and atomization air, along with spark generation, continues for a period of time after the fuel is shutoff. An emission abatement assembly is also disclosed.

Abstract: Methods and apparatuses for regenerating a NOx adsorber coupled with an exhaust of an engine. An actuator drives a throttle valve to a first position when regeneration of the NOx adsorber is desired. The first position is a position that causes the regeneration of the NOx adsorber. An actuator drives the throttle valve to a second position while regeneration of the NOx adsorber is still desired. The second position being a position that is more open than the first position and operable to regenerate a NOx adsorber.

Abstract: A dust collection apparatus includes a container and a suction pump that sucks dust and transports it into the container. A filter is provided on a side surface of the container. This filter passes air but prevents passage of the dust in the container. A pressure detector detects an internal pressure of the container. The internal pressure of the container fluctuates due to a variation in an effective area of the filter for allowing the air to pass according to the dust collected and accumulated in the container. A dust accumulating quantity calculator which determines a quantity of the dust in the container based on the pressure detected.

Abstract: A flow rate of gas supplied to a diesel particulate filter is increased when it is determined that rapid combustion of collected particulates, which are collected by the particulate filter, is likely to occur based on an operating state of an internal combustion engine. Alternatively, the flow rate of gas supplied to the filter is increased when it is determined that rapid combustion of the collected particulates is initiated based on a state of the particulate filter.

Abstract: A particulate filter system is provided including an exhaust system transporting emissions from an engine. A filter such as a diesel particulate filter is disposed in the exhaust system. An acoustic sensor is associated with the exhaust system for detecting one or more frequencies passing through the filter. The frequency corresponds to a filter state indicative of a clean, full, loading, or failed filter. One or more acoustic sensors may fluidly or mechanically coupled to portions of the exhaust system to determine the frequency caused by the exhaust flow through the filter. The acoustic emissions from the filter may be used to compare to a known filter state to determine the present filter state. Alternatively, more sophisticated mathematical approaches may be used in which processed filter information is compared to a known filter state to determine the present filter state.

Abstract: A method and mobile system for cleaning dirty gas from a newly stimulated gas well. The entire system is supported on a trailer or other mobile support so that it can be driven from well site to well site for short-term, post-stimulation use only. The system comprises a gas separator, such as a membrane separator. The system also includes a pretreatment assembly for preparing the gas for the gas separator. The pretreatment assembly may include separators, a heater, a guard vessel and a polishing filter. A chiller or heat exchanger cools the treated gas to a marketable temperature. A generator and a hydraulics plant provide power to the system. Each mobile system will be designed to treat gases with widely different operating conditions varying from well to well.

Abstract: The replacement of filters for Heating, Ventilating, and Air Conditioning (HVAC) is often time-consuming and labor-intensive. Organizations having responsibility for many apartment or dormitory units can spend a significant fraction of their man-hours replacing such filters. A novel approach to reducing the labor for this task is to attach one end of sheet-type filtering material to a dispensing roll, and the other end to a gathering roll; both rolls being affixed to a frame. The assembly is installed into an air duct and the filtering material allowed to blouse, somewhat. The flow of air is intermittent in typical HVAC systems, so when the air begins to flow, the filtering material is forced, due to its resistance to flow, in the direction of the flow. This energy—a force applied through a distance—is utilized by a lever arm bracket to advance the gathering roll. In this fashion, new material leaves the dispensing roll and is exposed to the air, while the dirty filter sheet accumulates on the gathering roll.

Abstract: A system and method for passive hypoxic training provides a person with a low oxygen (hypoxic) environment. Oxygen sensors automatically monitor and control oxygen levels to maintain the altitude desired. CO2 levels are monitored and CO2 is eliminated so that the air a person breathes is substantially clean and fresh. Exposure to a high altitude environment produces physiological changes in a person's body, which becomes more efficient at absorbing and transporting oxygen. Using the present method and system, athletes obtain the benefits of sleeping at a simulated altitude in the user's own home for six to twelve hours, rather than traditional altitude therapies in which athletes spend two to three weeks at high altitude before an athletic competition to obtain similar benefits. This system allows for “live high train low” altitude training that has been shown in controlled studies to provide superior benefits to “live high train high” training.

Abstract: A system for monitoring gas carry-under of a formation fluid exiting a gas separator by measuring a parameter of interest of the formation fluid exiting the gas separator is disclosed. The parameter of interest that can be correlated with the extent of gas entrained in the formation fluid exiting the separator can be the density of the formation fluid, or an absorbance spectrum of the formation fluid. A correlation of the measurement of the parameter of interest with a level of gas carry-under is made and a signal is transmitted to a device to control the supply of at least one additive to control the gas carry-under.

Abstract: A map which defines a relationship of an exhaust gas pressure P2 at the outlet of a filter (13) to a load Q and rotation speed Ne of an engine (1) is prepared, and an exhaust gas pressure P1 at the inlet to the filter (13) is determined from a differential pressure &Dgr;P between the front and rear of the filter and the outlet pressure P2 obtained by referring to the map. The inlet pressure P1 determined in this manner is used to determine an exhaust gas volumetric flow rate Q1, and thus an accurate particulate accumulation SM, which is required to determine the need for regeneration of the filter (13), can be calculated.

Abstract: An electronic flow measurement device (EFM), for use in conjunction with a flow meter in a pressurized gas line, has a microprocessor and read-only memory (ROM), and calculates and records gas flow rates corrected for variable factors such as gas pressure, temperature, and density. Look-up tables stored in the ROM contain intermediate values calculated in accordance with selected protocols for selected ranges of input variables such as gas temperature, pressure, density, and turbine “K” factors. Based on inputs received from gas temperature and pressure sensors, the EFM selects corresponding intermediate values from the look-up tables, and then uses these values to calculate corrected gas flow rates, using software residing in the EFM. The microprocessor's power consumption is significantly reduced because the use of look-up tables reduces the complexity and extent of calculations that the EFM needs to perform, as compared with performing all required calculations in the EFM.

Abstract: The present invention provides device and method for controlling air cleaning operation, in which an air conditioner with an air cleaner is made to clean air effectively proper to different pollutants. The device includes a memory having a plurality of operation modes set and stored therein for controlling operation of a fan proper to characteristics of air pollution sources, first means for selecting one of the plurality of operation modes stored in the memory, and a controlling part for controlling the fan according to a control program of the operation mode. The method includes the steps of selecting one of a plurality of operation modes, changing setting of an operation time period of the selected operation mode, reading the selected operation mode from the memory, and changing the operation time period of the operation mode to the set value, and controlling the fan according to the value of the changed operation time period and the value of the operation mode read from the memory.

Abstract: A method comprising: a) selecting a loading variable from operating variables, the loading variable being directly related to total energy input into the system and equipment constraint of the system; b) selecting a performance specification variable which is required to be kept within a defined target at all times during operation of the system; and c) pairing the performance specification variable with a manipulated variable having a mass/balance relationship to the performance specification which is not the loading variable and; d) controlling the manipulated variable to maintain the performance specification variable with the defined target.

Abstract: An air cleaner intake door is provided. An air cleaner with at least one sidewall and an opening defined in the sidewall has a door mounted over the opening. The door is rotationally movable between an open and a closed position and a cam extends from the door. A spring is in contact with the door for biasing the door towards a closed position.

Abstract: An exhaust filtration control system for creating environmentally protected zones. The system includes, a diverter valve, a valve actuator coupled to the diverter valve, a control switch electronically coupled to the valve actuator for switching the valve actuator between an engaged state and a disengaged state, a wireless transmitter, and a wireless receiver coupled to the control switch for receiving a signal from the wireless transmitter and for sending a signal to the control switch upon receiving a signal from the wireless transmitter.

Abstract: The treatment unit (16) comprises N adsorption units, N being greater than or equal to 1, operating on a parametrized cycle split uniformly into at most N phase times. Further more, use is made of a control unit (30) for controlling the treatment unit (16), designed to modify at least one parameter of the cycle. Each time there is a predicted change in the composition of the feed gas, the control unit (30) is sent a pre-established signal representing this change. The processing unit (30) then processes the said signal to determine the parameters of an exceptional operating cycle of the treatment unit (16) which cycle is suited to the said predicted change.

Abstract: A particulate filter system is provided including an exhaust system transporting emissions from an engine. A filter such as a diesel particulate filter is disposed in the exhaust system. An acoustic sensor is associated with the exhaust system for detecting one or more frequencies passing through the filter. The frequency corresponds to a filter state indicative of a clean, full, loading, or failed filter. One or more acoustic sensors may fluidly or mechanically coupled to portions of the exhaust system to determine the frequency caused by the exhaust flow through the filter. The acoustic emissions from the filter may be used to compare to a known filter state to determine the present filter state. Alternatively, more sophisticated mathematical approaches may be used in which processed filter information is compared to a known filter state to determine the present filter state.

Abstract: A thermoelectric particle precipitator for removing and collecting particles from a fluid stream. The thermoelectric particle precipitator utilizes one or more thermoelectric modules to create a temperature gradient which causes suspended particles in a fluid stream to undergo thermophoretic movement and precipitate on a surface on the cooled side of the temperature gradient. The collection surface may be a cooled surface of the thermoelectric module or a cooled surface of a thermal mass. The collected particles may be analyzed to determine their composition.

Abstract: An air deodorizing assembly including a frame having a liquid reservoir; a filter element connected to the frame; and a switch actuator connected to the frame. The switch actuator is adapted to cause an open electrical path to close when the frame is located proximate the open electrical path.

Abstract: An air filter assembly including a frame, a filter and an odor eliminator liquid. The frame forms an air flow channel. The filter is connected to the frame in the air flow channel. The filter includes at least one filter element. The odor eliminator liquid is located on a first one of the filter elements.

Abstract: An air filter assembly including a frame, a filter and an odor eliminator liquid. The frame forms an air flow channel. The filter is connected to the frame in the air flow channel. The filter includes at least one filter element. The odor eliminator liquid is located on a first one of the filter elements.

Abstract: An air deodorizing assembly including a frame having a liquid reservoir; a filter element connected to the frame; and a switch actuator connected to the frame. The switch actuator is adapted to cause an open electrical path to close when the frame is located proximate the open electrical path.

Abstract: A system and method for determining the condition of a filter in a forced air filtration system includes a blower motor and a fan mounted for rotation with an output shaft of the blower motor. A load sensor is operably connected to the blower motor for monitoring an electric load of the motor. As the filter becomes increasingly laden with airborne particles, the electric load changes. The load sensor generates a load value dependent on the electric load of the motor which is compared to a predetermined value. When the load value reaches the predetermined value, a signal is generated indicative of a filter change condition.

Abstract: An apparatus for treating exhaust gases. The apparatus includes an adsorbing tower containing an adsorbent to adsorb an impurity gas included in the exhaust gases. A desorbing tower heats the adsorbent to desorb the impurity gas from the adsorbent so that the adsorbent can be re-used. A transfer unit circulates the adsorbent between the adsorbing tower and the desorbing tower. A controller controls the temperature of the adsorbent. A helical heater is arranged in the desorbing tower to heat the adsorbent.

Abstract: An apparatus for treating exhaust gases. The apparatus includes an adsorbing tower containing an adsorbent to adsorb an impurity gas included in the exhaust gases. A desorbing tower heats the adsorbent to desorb the impurity gas from the adsorbent so that the adsorbent can be re-used. A transfer unit circulates the adsorbent between the adsorbing tower and the desorbing tower. A controller controls the temperature of the adsorbent. A helical heater is arranged in the desorbing tower to heat the adsorbent.

Abstract: A system for monitoring foaming or carry over, at a well site, of a formation fluid by taking a sample of the gas exiting from a high-pressure separator and either measuring the density of the sample or measuring the amount of oil particles present. A correlation of the density or optical density with a level of foaming is made and a signal is transmitted to a device to control the supply of at least one additive to control the foaming.

Abstract: A compression machine (compressor 4 and/or pump 5) of the plant (1) for the treatment of a fluid, typically by pressure swing adsorption, comprises at least one detector (7) for detecting clearance between a moving part (6) and a stator and delivering a measurement signal used so as to vary, depending on this measurement, the operation of the plant and especially to automatically shorten the phases during which the machine is running at an excessively high speed.

Abstract: An air dryer system for a trailer braking assembly is modified to provide a purge flow when the park brakes are actuated. An air reservoir, either the main air tank or a separate reservoir, is in operative communication with the trailer air dryer. A valve disposed at a supply end of the trailer air dryer selectively vents a purge flow to atmosphere in response to a park brake application. A restricting orifice limits the purge flow through the trailer air dryer to extend the purge time and maximize the removal of moisture from the air dryer.

Abstract: A filtering device for treating substances passing therethrough includes a filter cartridge having a cylindrical inner wall surrounded by a cylindrical outer wall. The inner and outer walls are spaced to define an annular space between them. A filtering media occupies the annular space and operates to remove contamination from a fluid flowing through the filter cartridge. First and second covers are located at opposite axial ends of the filter cartridge for sealing the system. At least one biasing assembly is disposed at one axial end of the filter cartridge for applying an approximately constant compression force to the filter medium. The compression force minimizes the formation of voids and the occurrence of bridging within the filtering media. A sensing mechanism, such as a Hall Effect sensor, can be applied to the filter cartridge for detecting changes in the filtering media which indicate the formation of voids or defects in the filtering media.