FAD dryer conditioning system and method

Abstract

A method, system, and apparatus for setting the rotational speed of the rotor of a compressed gas dryer system without communication from the associated compressor (e.g., without knowing the compressor's speed or load). Such communication is not always practical or possible (e.g., when the dryer may be provided by a different manufacturer than the compressor). In such cases, the speed or load at which the dryer should operate can be determined by performing a FAD calculation to determine the volumetric flow rate through an inlet into the drying zone of the dryer. This measurement can be made at the inlet (venturi or other nozzle) or elsewhere in the system (e.g., other inlet or outlet). Determining the flow rate of compressed gas to be dried can be done independently of communication with the compressor. This can be done by measuring inlet temperature, pressure, and pressure drop.

Description

[Technical Field]

[0001] The present disclosure relates to methods, systems, and apparatus for monitoring and controlling compressed gas dryers, and more particularly to methods, systems, and apparatus for monitoring, controlling, and optimizing the efficiency of rotary drum dryers in compressed gas systems, particularly where the rotational speed of the dryer's rotor is set without the need for control input (e.g., compressor speed or load) from the associated compressor. [Background technology]

[0002] Dry compressed air is used in a wide range of applications, including, but not limited to, food processing, chemical and pharmaceutical operations, pneumatic tools, HVAC and HVAC control systems, abrasive blasting, injection molding, airbrushing, and manufacturing (e.g., electronic component manufacturing). In the food industry, dry air is used to dehydrate grains, dairy products, vegetables, and cereals. In the electronics industry, dry compressed air is used, for example, to remove demineralized water and cleaning solvents from silicon devices and circuit boards.

[0003] Atmospheric air contains water vapour, which must be taken into account when producing compressed air. For example, a compressor with a working pressure of 7 bar and a capacity of 200 litres / second compressing air at 20°C with 80% relative humidity will release 10 litres / hour of water into the compressed air line.

[0004] Water and moisture in compressed air systems can cause erosion, corrosion, and biological effects, which can result in product spoilage, equipment malfunction, and system failure. For example, in compressed air lines, water is fluidized into an aerosol mist by turbulent air flow, and the droplets are propelled at high speeds until they collide with obstacles in their path (e.g., piping elbows, valve discs, orifice plates, or air motor blades). The resulting repeated collisions create pitting. Furthermore, the pits created by the high-velocity water aerosol mist provide a breeding ground for salt ions and acids, which further corrode the surface through chemical action. The weakened surface is then susceptible to stress corrosion due to mechanical vibration and flexing. Erosion can be controlled by eliminating liquid aerosols and particles in the air and by removing water vapor from the compressed air system, which can condense to form droplets. Therefore, in facilities where compressed air lines are exposed to low temperatures and prone to condensation, it is important to dry the air to a dew point below the lowest possible operating temperature.

[0005] In addition to erosion, moisture in compressed air systems can cause corrosion and destructive biological effects. Water and oil vapors can be removed by adsorption processes. Liquid aerosols can be removed from the air stream by means such as coalescing filters. Moisture corrosion in compressed air systems is particularly aggressive due to the absorption of corrosive agents from the air. Pure liquid water is not corrosive in itself, but when water is combined with salt particles or acid gases, highly corrosive solutions are formed. It is known that corrosion can be controlled by drying the air to its lowest possible dew point.

[0006] Furthermore, moisture in compressed air systems is harmful because it allows bacteria, fungi, and mold to grow, which creates acidic waste products that also contribute to corrosion in compressed air systems. Microorganisms also accumulate in instrumentation tubing and air motor bearings, which can result in failure, excessive wear rates, and seizure. Therefore, to control harmful biological effects, it is advantageous to dry the air to a dew point that reduces the relative humidity to below 10%.

[0007] Additionally, moisture in compressed air can cause product contamination by both direct and indirect means. Both water droplets and water vapor can be absorbed by the product in direct contact processes (e.g., chemical mixing) and paint spray applications. Water absorption can adversely affect the chemical and physical properties of the product.

[0008] Dry compressed air applications (e.g., in manufacturing) often use air with dew points between -40°F and -100°F, so it is advantageous to utilize a drying process in which the air is dried to its lowest possible dew point. For example, compressed air used in analytical instruments must be extremely pure and contain minimal levels of water vapor. Infrared analyzers and gas chromatographs used to analyze air for environmental chambers and physiological breath testing typically require consistent quality air and dew point levels below -60°F. Such high-purity air (called "zero air") is also beneficial in extending the life of sensitive components, preventing contamination of test samples, and preventing unwanted side reactions during analysis.

[0009] The degree of drying required is generally determined by analysis of each individual compressed air system, and the air drying system should be designed to reduce the water vapor content to the lowest dew point level.

[0010] There are known compressed gas dryer systems (e.g., rotary drum dryers) that are provided with a pressure vessel containing a drying zone and a regeneration zone. Such systems often also include a cooling zone. A rotatable drum is provided within the pressure vessel with a regenerative desiccant.

[0011] The pressure vessel includes an inlet to the drying zone for supplying compressed gas to be dried and an outlet for discharging the dried gas. Warm regeneration gas is supplied to the regeneration zone for regenerating the desiccant. The dryer further includes a driver that rotates the drum so that the desiccant is moved continuously through the drying zone and the regeneration zone (and, if applicable, the cooling zone).

[0012] Moisture removal from the air feed stream can be considered to depend on several factors, including the rate of flow of the gas stream, the rate of moisture adsorption and moisture content of the adsorbent, as well as the temperature and pressure of the air in the bed.

[0013] In many compressed gas dryer systems, the rotational speed of the dryer system rotor is set based on the rotational speed or load at which the compressor feeding the compressed gas dryer system is running. If this information is not readily available, it can be difficult to consistently operate the dryer system rotor at the appropriate rotational speed efficiently, provide compressed gas at the desired dew point, provide proper separation between the compressed gas to be dried and the regeneration flow, and maintain the desired regeneration circulation of desiccant through the system. This can occur in situations where the compressor is provided by one manufacturer and the dryer is provided by another, and communication between such components may not be practical.

[0014] One method for accurately predicting contamination levels in gas streams exiting the adsorption sector and optimizing the performance and fractionation efficiency of a rotary drum adsorber system is described in U.S. Patent No. 6,527,836. Such a method involves providing a complex proposed set of drum dryer design and operating parameters and initial operating conditions, calculating a predicted dew point under such conditions, determining temperature information from the regeneration and cooling sectors, and displaying the sector temperature profile and discharge temperature at the predicted dew point for evaluation by an engineer to provide optimal system performance and achieve the lowest effluent dew point. Such a known method involves determining the average or mixed concentration exiting the adsorption sector across its surface and the mixed stream discharge temperature exiting the cooling sector. The average or mixed discharge concentration in the adsorption sector is determined using classical adsorption equations. J0=0.5[1-erf{(N) 1 / 2 -(NT) 1 / 2}] (almost linear isotherm) (1) J0=0.5[1-erf{(N) 1 / 2 -(NT) 1 / 2}] (almost constant isotherm) (2) where J0=c1 / c0(3) N=L / H d (4) T=(c0-c1)(μ0τ-Vε) / [(nn i )ρ a LA x ) (5) c1: Effluent pollutant concentration c0: influent pollutant concentration N: Number of mass transfer units, dimensionless T: Material balance ratio, solute adsorbed per adsorbent volume L: Adsorbent bed length H d : Mass transfer unit height μ0: mass flow rate in the adsorption sector τ: time in the adsorption sector V: adsorbent bed volume in the adsorption sector ε: Void fraction of the adsorbent bed n: adsorbent bed equilibrium volume per unit weight n i : initial concentration in the adsorbent bed ρ a : Adsorbent bed density A x : Adsorption section cross-sectional surface area

[0015] In such known methods, Equation (1) above is used with adsorbents characterized by approximately linear isotherms (e.g., silica gel and activated alumina, as examples provided). Equation (2) above is used with adsorbents characterized by approximately constant isotherms (e.g., molecular sieves, or zeolites and activated titanium dioxide, as examples provided). In the cooling sector, Equation (1) is used to determine the temperature profile; the integral of this equation provides the mixed stream discharge temperature, and the terms in Equation (1) are defined in terms of heat transfer. J0=(t-t0) / (t1-t0) (6) N=L / H (7) T=c p (τ c u c -Vε) / (c pa ρ a LA x ) (8) t: discharge temperature t0: Initial bed temperature t1: Air inlet temperature H: Heat transfer unit height c p : Heat capacity of the gas τ c : Time in the cooling sector u c : mass flow rate through the cooling sector V: Adsorbent bed volume in the cooling sector c pa : Heat capacity of the adsorbent

[0016] In these methods, the time in the cooling sector (τc) is equal to (φc / 2π) / rpm, where φc is the cooling sector angle in radians.

[0017] Known methods consider two thermal fronts to be established in the regeneration sector before entering the cooling sector. The first thermal front approaches the equilibrium temperature where desorption occurs, and the second, lagging front approaches the elevated inlet temperature. Known methods (e.g., U.S. Pat. No. 6,527,836) illustrate the two thermal fronts and the time period during which the regeneration sector is at equilibrium temperature in a graphical display of regeneration temperature versus time. This graph shows a two-humped temperature curve that can be used to analyze the performance of a rotary drum adsorber system. After the first hump, there is a period during which the temperature in the regeneration sector remains constant, indicating the equilibrium temperature. According to U.S. Pat. No. 6,527,836, this temperature remains constant as long as some moisture remains in the regeneration sector. A given flute of the adsorbent drum is considered regenerated when the second hump begins. Known methods (e.g., U.S. Pat. No. 6,527,836) allow a user to adjust various inlet conditions (e.g., inlet temperature, system pressure, flow rate, regeneration inlet temperature, regeneration flow rate, and / or drum rotation speed) and generate graphs of regeneration temperature versus time at various conditions to show the rotating drum adsorbent system performance changes in response to such adjustments.

[0018] Additionally, using the computerized method, a user can generate various graphical displays of data (e.g., cooling temperature versus time, cooling temperature versus flute length, dew point versus inlet temperature, dew point versus regeneration temperature, dew point versus regeneration flow rate, dew point versus motor rotation speed, and dew point versus flow rate, for example) to control the operating conditions of the rotary drum adsorber system to improve its performance and achieve the lowest effluent dew point.

[0019] Furthermore, known methods for accurately predicting contamination levels in gas streams exiting adsorption sectors and optimizing the performance and fractionation efficiency of rotary drum adsorber systems (such as those described by U.S. Pat. No. 6,527,836) provide a means for displaying sector temperature profiles and discharge temperatures, as well as other system conditions, for evaluation to improve the design of the rotary drum adsorber system for optimal performance. In these known methods (such as those described by U.S. Pat. No. 6,527,836), the process steps and equations and calculations of the computerized methods are embodied in a proprietary computer program to provide in-depth knowledge for accurately predicting the performance and controlling the operation of rotary drum adsorber processes and systems based on a proposed set of system parameters, initial operating conditions, varied operating characteristics, and performance levels of different sized rotary drums, as well as other variations of system design parameters under any number of different operating conditions. The computer program is specifically designed to quickly and easily generate graphical displays of sector temperature profiles, discharge temperatures, and other system data for evaluation to achieve maximum system performance and optimized product.

[0020] Such known systems provide for inputting information including main flow (SCFM), inlet temperature (°F), regeneration temperature (°F), system pressure (psig), regeneration flow (SCFM), inlet relative humidity, drive motor speed (rpm), and blower flow rate (SCFM). In addition, the computer program used in such methods provides for selection of the rotary drum system model. Selection of the drum model number determines the diameter and length of the adsorbent drum. For example, the diameter and length of different models can be 14.5 inches and 200 mm, 14.5 inches and 400 mm, 18.5 inches and 400 mm, or 24.5 inches and 400 mm. Furthermore, the computer program used in these methods provides for selection of the specific manufacturer of the adsorbent drum. Suitable computer programs for known methods include the options of Nichias (silica gel or GX7 model) and Siebu Giken (silica gel or molecular sieve). By selecting a model number, specific information can be obtained about the physical characteristics of the rotating drum, including the height and width of the flute triangle, the thickness of the silica-retaining media, the approximate seal width, the angle of the adsorption sector, and the angle of the regeneration sector.

[0021] Using input information including initial operating conditions and drum design parameters, a computer program of known methods (such as that described by U.S. Pat. No. 6,527,836) then calculates various information regarding the product flow, regeneration sector, and cooling sector. For the product flow, the program can determine the predicted outlet pressure dew point (°F) and outlet temperature (°F). For the regeneration sector, the computer program can determine the equilibrium temperature (°F), final flute outlet temperature (°F), average outlet temperature (°F), and flow rate (SCFM). For the cooling sector, the computer program can determine the final flute outlet temperature (°F), average outlet temperature (°F), and flow rate (SCFM). In addition, the computer program provides the condenser inlet temperature (°F), useful capacity [#H20 / 100#Dscc], and water load [#H20]. Thus, the computer programs used in these known methods provide system information and graphical displays as needed or desired to evaluate and / or control the performance of rotary drum adsorber processes and systems to obtain maximum performance and optimized products.

[0022] Furthermore, a graphical display of the information that can be provided by the computerized method is generated using the following primary initial operating conditions and system parameters: main flow = 450 SCFM; inlet temperature = 100°F; regeneration temperature = 300°F; system pressure = 100 psig; regeneration flow = 200 SCFM; blower head = 30WC; and rotating drum = RDD450 model. Additionally, the following conditions are included: inlet relative humidity = 85%; drive motor speed = 1.2 RPM; blower temperature = 100°F; and blower flow rate = 225 SCFM. The initial operating conditions and system parameters provided herein are for illustrative purposes only and can be modified as appropriate by the user of the computerized method.

[0023] Using this input information, a computer program in a known manner (such as that described by U.S. Pat. No. 6,527,836) calculates a product flow pressure outlet dew point of 1.3°F and a product flow outlet temperature of 125.3°F. The computer program determines the following information for the regeneration sector 40: the equilibrium temperature is 156.9°F, the last flute outlet temperature is 299.2°F, the average outlet temperature is 166.7°F, and the flow rate is 200 SCFM. For the cooling sector 42, the computer program calculates a last flute outlet temperature of 127.5°F, an average outlet temperature of 264.3°F, and a flow rate of 28.5 SCFM. Additionally, the computer program determines the condenser inlet temperature to be 178.9°F, the useful capacity [#H20 / 100#Dscc] to be 9.4, and the water load [#H20] to be 0.53.

[0024] Although known methods (such as those described by U.S. Pat. No. 6,527,836) have been described as accurately predicting contamination levels in gas streams exiting the adsorption sector and optimizing the performance and fractionation efficiency of rotary drum adsorber systems, such methods and systems are overly complex and require significant computational capacity and time delays resulting from such calculations.

[0025] Accordingly, the inventors of the present disclosure have identified a need for efficient and reliable adsorption processes and systems for improving the purity of air feed streams to achieve the lowest effluent dew points, as well as simpler methods for designing, monitoring, and controlling such adsorption processes and systems. Additionally, there is a need to reduce the moisture content in compressed air systems, but as noted above, there is a need to do so in a simple yet efficient manner that balances the need to provide a drying process in which the air is dried to its lowest possible dew point while simultaneously reducing energy consumption in the process and unnecessary wear on the air drying system.

[0026] It has been discovered by the inventors of the present application that the decision at what speed or load to run the dryer can be made using details provided solely from and input to the dryer, such that communication with the associated compressor does not need to be provided. Such a system and method allows a dryer from one manufacturer to be paired with a compressor from another manufacturer without the need to provide communication between the dryer and compressor to ensure that the dryer operates at the appropriate speed or load at a given time during operation. [Prior art documents] [Patent documents]

[0027] [Patent Document 1] U.S. Patent No. 6,527,836 Summary of the Invention [Means for solving the problem]

[0028] A compressed gas dryer system is provided, the compressed gas dryer system including: a compressed gas source providing compressed gas to be dried; a regeneration gas source providing regeneration gas; a pressure vessel defining a drying zone and a regeneration zone, the drying zone having an inlet and an outlet, where the compressed gas to be dried is received into the drying zone through the inlet and the dried compressed gas exits the drying zone through the outlet, and the regeneration zone having an inlet and an outlet, where the regeneration gas is received into the regeneration zone through the inlet and the regeneration gas exits the regeneration zone through the outlet; and a driver configured to drive rotation of a rotor associated with the pressure vessel in a predetermined rotational direction. The dryer system is configured to determine a flow rate of the compressed gas to be dried in the drying zone through the inlet. A controller is provided to set the rotational speed of the rotor based on the determined flow rate of the compressed gas to be dried.

[0029] In one embodiment, measurements can be taken at the inlet to the drying zone to determine the required flow rate (e.g., at a venturi or other nozzle associated with such inlet), while in other embodiments, such measurements can be taken elsewhere in the system (e.g., at the drying zone outlet, the regeneration zone inlet, the regeneration zone outlet, the piping between the compressor and the dryer system, or elsewhere).

[0030] In one embodiment, a compressed gas dryer system includes a venturi or other nozzle associated with an inlet to a drying zone, where a compressed gas supply to be dried passes across the venturi or other nozzle as it enters the drying zone, and the system is configured to determine a flow rate (e.g., a volumetric flow rate) across the venturi or other nozzle. While a venturi or other nozzle may be particularly well suited for determining the flow rate, other types of gas flow instrumentation or measurement techniques may alternatively or additionally be used (e.g., including, but not limited to, Coriolis mass flow meters, thermal flow meters, ultrasonic flow meters, rotameters, optical flow meters, etc.). Indeed, a variety of sensors and techniques may be used to determine the flow rate.

[0031] In one embodiment, the determination of the volumetric or other flow rate can be based on temperature and pressure measurements of the compressed gas taken at the inlet and the pressure drop across the venturi or other nozzle. From these measurements, the density of the compressed gas at the inlet, the mass flow rate across the nozzle, and the volumetric flow rate across the nozzle can be determined. The system further includes a controller configured to set the rotational speed of the rotor based on the determined flow rate through the venturi or other nozzle.

[0032] A related method for setting the rotational speed of a rotor in a compressed gas dryer system is disclosed, without reference to the rotational speed or load of a compressor providing the compressed gas to be dried in the compressed gas dryer system. The method can include providing a compressed gas dryer system including: a compressed gas source providing the compressed gas to be dried; a regeneration gas source providing a regeneration gas; and a pressure vessel defining a drying zone and a regeneration zone, the drying zone having an inlet and an outlet, wherein the compressed gas to be dried is received into the drying zone through the inlet and the compressed gas exits the drying zone through the outlet, and the regeneration zone having an inlet and an outlet, wherein the regeneration gas is received into the regeneration zone through the inlet and the regeneration gas exits the regeneration zone through the outlet. A driver is provided that is configured to drive rotation of a rotor associated with the pressure vessel in a predetermined rotational direction. The dryer system is further configured to determine a flow rate of compressed gas through the inlet of the drying zone; and to set the rotational speed of the rotor based on the determined flow rate through the inlet of the drying zone. The rotational speed of such rotors is set without reference to any input or communication provided to the compressed gas dryer system from the compressed gas source. In one embodiment, the determination of the flow rate of the compressed gas to be dried can be made by taking measurements at the inlet to the drying zone of the dryer, although it will be appreciated that in other embodiments, measurements can be taken elsewhere in the system, which measurements can then be used to determine the flow rate of the compressed gas into the drying zone. For example, measurements can be taken at the outlet of the drying zone, at the inlet of the regeneration zone, at the outlet of the regeneration zone, or even elsewhere (e.g., in the piping between the compressor and the dryer system).

[0033] In one embodiment, a compressed gas dryer system includes a venturi or other nozzle associated with an inlet to a drying zone, across which a compressed gas source to be dried passes as it enters the drying zone. In one embodiment, the method includes determining a flow rate (e.g., volumetric flow rate) of the compressed gas across the venturi or other nozzle without reference to any input or communication provided from the compressed gas source (e.g., a compressor). The rotational speed of the rotor can then be set based on the determined flow rate of the compressed gas through the venturi or other nozzle, as determined based on these measurements.

[0034] While a venturi or other nozzle is a particularly suitable way of measuring such flow rates (e.g., by measuring the temperature, pressure, and pressure drop across such a venturi or other nozzle), it will be apparent that additional or alternative techniques and devices may be used to obtain the desired measurements that enable the determination of the desired flow rate of the compressed gas to be dried. Examples of such alternative flow meters are set forth above and may be used alternatively or additionally.

[0035] In one embodiment, a hardware storage device or memory storage is provided having stored thereon computer-executable instructions that, when executed by one or more processors of a computing system, configure the computing system to perform a method as described.

[0036] In one embodiment, the determination of flow rate (including any intermediate determinations such as density) can be made through measurements of temperature and pressure at the venturi or other nozzle inlet and the pressure drop across the venturi or other nozzle. All necessary calculations can be based on these simple measurements.

[0037] In one embodiment, the rotational speed of the rotor is set without any controller area network (CAN) or other communication being provided between the dryer system and the associated compressor that generates the stream of compressed gas that is fed to the compressed gas dryer system.

[0038] In one embodiment, the rotor rotation speed is set to a value of about 1 RPH (revolutions per hour) to 5 RPH.

[0039] In one embodiment, a nozzle associated with the inlet into the drying zone includes a venturi (e.g., a venturi ejector). In one embodiment, a pitot tube, keel probe, or other sensor can be used to measure the pressure drop across such a venturi or other nozzle associated with the inlet.

[0040] In one embodiment, the volumetric flow rate (e.g., in l / s) is determined by determining (e.g., calculating) the gas density at the inlet (e.g., based on temperature and pressure measurements at the nozzle), determining (e.g., calculating) the mass flow rate of the gas based on the pressure drop across a venturi or other nozzle, and determining the volumetric flow rate therefrom.

[0041] In one embodiment, the density of the gas at the inlet section is determined based on the pressure and temperature of the gas at the inlet section.

[0042] In one embodiment, the density is determined (e.g., calculated) using the following formula:

[0043]

number

[0044] where P [bar(a)] is the pressure at the venturi or other nozzle inlet; T [°C] is the temperature at the venturi or other nozzle inlet; and ρ is the density of the gas at standard conditions (i.e., at 20°C and 1 bar).

[0045] In one embodiment, the mass flow rate of a gas across a venturi or other nozzle is determined using the following equation:

[0046]

number

[0047] where C is the flow coefficient; ε is the expansibility coefficient; d is the diameter at the exit for the venturi or other nozzle; Δp is the pressure drop across the venturi or other nozzle; ρ is the density of the gas at the inlet (e.g., as calculated above); and β is the diameter ratio (Dout / Din) for the venturi or other nozzle.

[0048] In one embodiment, the mass flow rate can be determined according to a simplified version of the above equation, where the flow coefficient (C) and expansibility coefficient (ε) are each assumed to be 1. In such a case, the simplified equation is:

[0049]

number

[0050] where d_out is the diameter at the exit for the venturi or other nozzle; dP is the pressure drop across the venturi or other nozzle; ρ1 is the density of the gas at the inlet; and β is the diameter ratio (Dout / Din) for the venturi or other nozzle.

[0051] In one embodiment, the volumetric flow rate as free air delivery (FAD) is determined using the following formula:

[0052]

number

[0053] where QM is the mass flow rate of the gas across the venturi or other nozzle (as determined above); and ρ0 is the density of the gas at standard conditions.

[0054] In one embodiment, the compressed gas source is a compressor and the regeneration gas source is a portion of the compressed gas stream output by the compressor.

[0055] Features from any of the disclosed embodiments can be used in combination with each other without limitation. Additionally, other features and advantages of the present disclosure will become apparent to those skilled in the art upon consideration of the following detailed description and accompanying drawings. [Brief explanation of the drawings]

[0056] [Figure 1] 1 illustrates a first embodiment of a compressor installation including a dryer system. [Figure 2] FIG. 1 illustrates another embodiment of a compressor installation including a dryer system. [Figure 3] FIG. 1 illustrates another embodiment of a compressor installation including a dryer system. [Figure 4] FIG. 1 illustrates another embodiment of a compressor installation including a dryer system. [Figure 5] FIG. 1 illustrates another embodiment of a compressor installation including a dryer system. [Figure 6] FIG. 1 illustrates another embodiment of a compressor installation including a dryer system. [Figure 7A] 7 shows an embodiment and further details from the embodiment of FIGS. 1 to 6. FIG. [Figure 7B] 7 shows an embodiment and further details from the embodiment of FIGS. 1 to 6. FIG. [Figure 7C] 7 shows an embodiment and further details from the embodiment of FIGS. 1 to 6. FIG. [Figure 8A] 7A-7C show embodiments of start and stop control devices that can be used to drive the drums in the embodiments of FIGS. 1-6. [Figure 8B] 7A-7C show embodiments of start and stop control devices that can be used to drive the drums in the embodiments of FIGS. 1-6. [Figure 9] FIG. 10 illustrates bands defined by minimum and maximum reference rotational speeds according to an embodiment. [Figure 10] FIG. 1 is a schematic diagram illustrating an existing installation including a compressor for generating compressed air and an associated dryer system, where communication is required between the dryer system and the compressor to determine at what speed the dryer rotor should run. DETAILED DESCRIPTION OF THE INVENTION

[0057] The drawings are included to provide a better understanding of the components and are not intended to be limiting in scope but rather to provide an exemplary illustration.

[0058] The inventive concepts of the present disclosure will be described below with reference to embodiments and with reference to the drawings. However, the claimed invention is not limited thereto. The drawings described are merely schematic and non-limiting in scope. In the drawings, the size of some of the elements may be exaggerated and not drawn to scale. This is for ease of illustration. The dimensions and relative dimensions do not necessarily correspond to practical embodiments of the invention.

[0059] Moreover, terms such as first, second, and third may be used to distinguish between like elements and not necessarily to describe a sequential or chronological order, and the terms are interchangeable under appropriate circumstances, and embodiments of the invention may be practiced in sequences other than those described or illustrated herein.

[0060] Additionally, terms such as "top," "upper," "bottom," "lower," "above," and "below" in the specification and claims are used for purposes of example and not necessarily to describe relative positions. These terms are interchangeable under appropriate circumstances, and the embodiments of the invention described herein can be practiced in orientations other than those described or illustrated herein.

[0061] Additionally, various embodiments that may be described as "preferred embodiments" should be construed as merely illustrative of ways and modes for carrying out the invention, and not as limitations on the scope of the invention.

[0062] The terms "comprising," "including," or "having," as used in the claims, should not be interpreted as being limited to the means or steps thereafter described. These terms should be interpreted as specifying the presence of the described features, elements, steps, or components as they are mentioned, but not as excluding the presence or addition of one or more other features, elements, steps, or components, or groups thereof. Thus, the scope of the expression "an apparatus or device comprising means A and B" should not be interpreted as being limited to an apparatus or device consisting only of components A and B. For purposes of this disclosure, although only parts A and B of the device are specifically recited, it is intended that the claims should further be interpreted to include equivalents of these parts.

[0063] Generally, the compressed gas drying system of the present disclosure includes a pressure vessel containing a drying zone and a regeneration zone, and a rotating section or rotor (e.g., a rotatable drum within the pressure vessel). The rotor or drum is a multi-chamber adsorbent fractionator containing an adsorbent medium that acts as a regenerable desiccant. Additionally, a cooling zone may be included.

[0064] In a first embodiment of a compressed gas dryer system shown in FIG. 1 , a dryer 10 for a compressed gas system is provided for a compressed gas source 60. The compressed gas source 60 can be, for example, a compressor. However, a dryer system including the dryer 10 can be provided with other compressed gas sources, such as a pre-compressed gas tank, reservoir, or supply pipe or line. Furthermore, multiple dryers 10 can be provided within a compressed gas system or along a compressed gas line or pipe. The dryer 10 includes a pressure vessel 11 having rotational symmetry in which a drying zone 12, a regeneration zone 13, and optionally a cooling zone 29 are defined. A rotor (e.g., drum 14) is provided within the rotational symmetry, providing a multi-chamber adsorbent fractionator containing an adsorbent medium, which serves as a regenerable desiccant. The adsorbent medium can include silica gel, activated alumina, molecular sieves, activated titanium dioxide, or activated carbon. A driver 114 or drive means is provided to rotate the drum about axis X relative to a rotational symmetry, i.e., to rotate the drum 14 within the rotational symmetry or to rotate the rotational symmetry around a stationary drum, so that the desiccant moves sequentially through the drying and regeneration zones. The driver 114 can include an electric motor. The driver 114 shown in the figures is shown schematically. While the driver 114 in FIG. 1 is aligned with the rotational axis X of the drum 14, this is not necessarily the case. The driver 114 can be offset from the rotational axis of the drum 14. The motor of the driver 114 can be controllable, variable speed, or controllable only by being turned on and off.The driver 114 may further cause the drum 14 to rotate by a drive means, which may include a transmission, gears, pulleys, belts, chains, and / or a drive shaft or other means for transmitting rotation from a motor or engine to cause rotation of the drum. Additionally, the driver 114 may be within the pressurized volume of the dryer or may be external to the pressurized volume of the dryer.

[0065] Compressed gas to be dried is supplied to drying zone 12 within pressure vessel 11 via main line 18, which supplies the compressed gas to be dried to inlet 15 of the drying zone. The dried, compressed gas exits the drying zone at outlet 16, which is connected to the remaining downstream portion of the compressed gas system (not shown). Regeneration gas is provided to regeneration zone 13 within pressure vessel 11 via connecting line 17, which provides regeneration gas or air from a regeneration gas source 67 to inlet 25 of regeneration zone 13. Regeneration air exits regeneration zone 13 at outlet 26 to connecting line 19, which can be returned to regeneration air source 67 through a supply line (not shown) or can be further used as described in various embodiments provided below. As described herein, regeneration gas source 67 can be provided with compressed gas from compressed gas source 60, for example, by a compressor. Or alternatively, regeneration gas supply 67 can be provided with regeneration air or gas from an entirely separate source (e.g., from another compressor or a separate pipe, line, or compressed gas system, etc.). Cooling zone 29 can be supplied with coolant by a separate refrigeration supply line (not shown). As shown, the flow of regeneration gas into inlet section 25 and out of outlet section 26 can be countercurrent to the flow of compressed gas to be dried entering inlet section 15 and exiting at outlet section 16.

[0066] In the embodiment according to FIG. 1 , a temperature sensor (T1) can be provided to measure the temperature of the compressed gas flow at the inlet 15 of the drying zone 12. Such a temperature sensor at the nozzle inlet of the dryer 10 can be used in determining the density and flow rate of the compressed gas into the dryer 10, as described herein, even in the absence of communication from a compressor or other compressed gas source to the dryer (e.g., no CAN cable, etc.). Other temperature sensors can additionally be provided in the dryer system, for example, at various inlet and outlet locations, as described, for example, in Applicant's patent application Ser. No. 63 / 333,284, entitled "Temperature-Based Monitor and Control of a Compressed-Gas Dryer," filed April 21, 2022, which is incorporated herein by reference in its entirety. Temperature sensor T1 (or any other temperature sensor in dryer 10) may include one or more thermocouples, liquid or gas thermometers, electric thermometers (including, for example, electrical resistance thermometers, silicone diodes, bimetallic devices, valve and capillary sensors, sealed bellows, and / or radiation temperature measuring devices), or any other type of temperature sensing device. While temperature sensor T1 is shown positioned at the inlet into the drying zone, it will be recognized that other placements are possible, where other measurements can be used to determine the flow rate of compressed gas into the drying zone.

[0067] One or more pressure sensors may also be present at the inlet to measure the inlet pressure and the pressure drop across the venturi or other nozzle as the compressed gas passes through it. While FIG. 1 simply specifies ΔP at this location, it will be recognized that more than one sensor may be present to determine both the pressure at the nozzle inlet and the pressure drop across the venturi or other nozzle. Any of a variety of pressure sensors may be used, including, but not limited to, a Pitot tube, a Keel probe, or any other type of pressure sensing device. While the pressure sensor is shown positioned at the inlet into the drying zone, it will be recognized that other placements are possible, where other measurements may be used to determine the flow rate of compressed gas into the drying zone. For example, measurements may be taken at the drying zone outlet 16, at the regeneration zone inlet 25, at the regeneration zone outlet 26, in the line 18 carrying the compressed gas, etc. It will be apparent that various measurements may be taken at various locations to determine the flow rate of compressed gas into the drying zone to be dried, and the specific embodiment illustrated and described in the figures is merely exemplary. For example, a mass balance can be performed with any such measurements taken at various outlets, inlets, or other locations in the system to determine the flow rate of compressed gas into the drying zone.

[0068] In the embodiment of FIG. 1 , a control unit or controller 100 is provided. Controller 100 includes a processor 150 (e.g., a microprocessor), memory storage 160, an output interface 170, and an input interface 180. Controller 100 receives input signals (which can be received through wired or wireless means) through input interface 180 and processes received sensor signals obtained from sensors in the dryer system. For example, controller 100 can receive temperature and pressure signals from temperature and pressure sensors T1, P1, and P2 (see FIG. 2 ) as well as other sensors present in the dryer system. As described herein, controller 100 outputs control signals to components of the dryer system through output interface 170. As described in more detail below, based on the received sensor signals obtained from the sensors of dryer system 10, controller 100 sends control signals to adjust operating parameters of the dryer system. For example, in a preferred embodiment, the controller 100 is configured to send a control signal 101 to the driver 114 to adjust the rotational speed of the driver's rotation of the drum or to turn the driver 114 on or off depending on the input the driver 114 is configured to receive.

[0069] Importantly, in the present system and method, control of the speed of rotation of the driver can be determined without communication with the compressor or other compressed gas source. For example, no CAN cable or other communication is required between the compressor or other compressed gas source and the dryer system to determine what speed the driver should operate at. Typically, in a compressed gas facility 1000 such as that shown in FIG. 10 , the load or speed at which the compressor 1100 is running is communicated to the dryer system 1200, and the rotational speed of the driver of the dryer system is determined based on input from the compressor 1100 or other compressed gas source to provide efficient operation of the dryer 1200. In the present system, the rotational speed or load at which the compressed gas dryer system operates is completely independent of any communication with the compressor or other compressed gas source. This is particularly advantageous when the dryer is from a different manufacturer than the compressor, or when communication between such components is otherwise impractical.

[0070] In the embodiment of the compressed gas dryer system shown in FIG. 2, a dryer 10 for compressed gas is provided in a compressed gas supply (e.g., compressor 60). Similar elements as shown in the embodiment of FIG. 1 are included in the embodiments of FIGS. 2-4 and 5-6 and are labeled with similar reference numerals. Compressor 60 can include a first compression stage 61, a second compression stage 62, and an interposed intercooler (IC) 63 and aftercooler (AC) 65. In the embodiment shown in FIG. 2, at the outlet side of compressor 60, a portion of the compressed gas to be dried (having an elevated temperature due to compression) is branched off and passed to a regeneration zone (via connecting line 17) for desiccant regeneration. In FIG. 2, this is shown as occurring without further heating or cooling of the partial stream. In other embodiments, the partial flow can first be further heated by an active heating device 31 (FIG. 3) (e.g., an electric heater, a gas heater, a steam heater, or other heater). 4, partial flow 51 is first further divided into a first partial flow 52 and a second partial flow 53, and only first partial flow 52 is further heated by a heating device 54. As shown, first partial flow 52 and second partial flow 53 can be introduced into different regions of regeneration zone 13, respectively.

[0071] As shown in the embodiment of FIG. 5, in the delivery line from the compressor 60 to the inlet section 15, the compressed gas can pass through a heat exchanger (heat exchanger HE) 64 and / or a cooling device (aftercooler AC) 65.

[0072] 5 and 6, connecting lines 77, 97 are provided at the outlet side of the dryer for branching off a partial flow stream of dried compressed gas, which is led through a heat exchanger 64, heated by the heat present in the feed stream as a result of compression, and then further led to the regeneration zone 13.

[0073] In each of the embodiments according to Figures 2 to 6, the partial flow for regeneration is returned via a connecting line 19 to the main line 18 for the supply flow of compressed gas to be dried. This is done by a controllable device, such as a Venturi ejector 21 or other controllable device (e.g., another type of nozzle) for creating a pressure difference. After exiting the drying zone 12, the flow can be split for regeneration as shown. One or more cooling devices (e.g., the illustrated aftercooler 65 ("aftercooler AC") and / or regeneration cooler 20 ("regeneration cooler RC") and / or process cooler 91 ("process cooler PC")) can be provided in the connecting line 19 and / or the main line 18 and / or in the inlet section 15 (after merging), each cooler being provided to cool the respective gas flow with a coolant (e.g., cooling water or ice water).

[0074] 1, in the embodiments according to Figures 2-6, a temperature sensor T1 can be provided to measure the temperature of the compressed gas flow at the nozzle inlet. As noted above, various other temperature and pressure sensors can be provided elsewhere in the system, as described in Applicant's patent application Ser. No. 63 / 333,284, entitled "Temperature-Based Monitor and Control of a Compressed-Gas Dryer," filed Apr. 21, 2022, and U.S. patent application Ser. No. 18,303,939, having the same title, filed with the USPTO on Apr. 20, 2023, which claims the benefit of priority to U.S. Provisional Application Ser. No. 63 / 333,284, both of which are incorporated herein by reference in their entireties. As described herein, by measuring or determining the temperature at the nozzle inlet, the pressure at the nozzle inlet, and the pressure drop across the nozzle, the flow rate into the drying zone can be calculated or determined, and from that information the rotational speed of the dryer rotor can be set. This can advantageously be done without reference to the speed or load at which the compressor 60 is running.

[0075] The output signals or data from the temperature and / or pressure sensors T1, P1, and P2, respectively, can be transmitted, either through hard-wiring or wireless communication, to a control unit or controller 100 for use in setting the rotational speed of the rotor of dryer 10 based on the flow rate of compressed gas in drying zone 12. Other temperature, pressure, or other measurements can, of course, also be transmitted to controller 100 for use in setting the rotational speed or other operating parameters of the system.

[0076] In addition to measuring the temperature T1 at the nozzle inlet of the venturi ejector 21 or other nozzle into the drying zone, in the embodiment illustrated in Figures 1 to 6, one or more pressure sensors are provided to measure the nozzle pressure and the pressure differential across the venturi ejector or other nozzle for compressed gas flow, allowing the determination of gas flow from these three measurements.

[0077] In the embodiments according to Figures 1 to 6, in each case a control unit 100 is provided. Each of the provided sensors can be provided with means for communicating with the control unit 100. The communication connections can be wireless or wired, and for the sake of simplified clarity, they are not shown in Figures 1 to 6. Respective output signals or data from these sensors can be transmitted to the control unit or controller 100 through either hard-wired or wireless communication and can further be used by the controller 100 to adjust or modify various operating parameters of the dryer 10 (in particular the rotational speed of the rotor of the dryer system).

[0078] In the embodiments according to Figures 2 to 6, the combining means for combining in each case at least the main flow of the feed gas to be dried and the partial flow for regeneration are shown to include a nozzle 21. The control unit 100 can be arranged to process at least one measurement value provided by the above-mentioned sensors (e.g., T1, the pressure at the nozzle, and the pressure drop across the nozzle, i.e., ΔP or dP21), to determine a control signal based on the measurement value, and to apply the control signal to one or more controllable devices. For example, the driver 121 and the rotor driver 114 associated with the nozzle 21 can include a controllable device. For example, the nozzle 21 (e.g., a Venturi ejector) can be equipped with a controllable opening controlled by the driver 121. The driver 114 can, of course, be controlled with respect to the speed of rotation it imparts to the dryer drum 14 or other rotor. Examples of other controllable devices that can use measurement data to determine operating parameters include a blower with a control for blower speed; or multiple smaller venturi ejectors or other nozzles arranged in parallel with respective controls for opening or closing them. This has the advantage that the controllable device can be smaller in size than a single venturi ejector and therefore can be better integrated into a pressure vessel. Alternatively, the controllable device can include a venturi ejector with a controllable bypass around it. Other controllable devices are also possible.

[0079] In a rotary drum dryer, it can be important to ensure that the drum is rotating in the correct direction at all times and at a speed that matches the speed of the required drying load. For example, drum 14 in the embodiment of FIG. 1 is shown as rotating in a counterclockwise direction, as indicated by the rotation arrow. In the examples described herein, the drum or rotor is shown as being configured to rotate in a counterclockwise direction when viewed from above. Of course, the inventive concepts described herein are not so limited, and a dryer system could include a pressure vessel and internal rotor configured to rotate in a clockwise direction when viewed from above, although this may be less common in the industry.

[0080] Drum rotation can be monitored by sensors provided in the motor, in or on the rotary drum, or in some part of the dryer system to directly measure the position or rotation vector of the rotary drum, the rotary drum shaft, or within the motor itself. For example, such rotation sensors can include a Hall Effect sensor or a set of Hall Effect sensors associated with one or more magnets. Other sensors are also possible. In one embodiment, temperature-based monitoring of rotational position, speed, and / or direction can be provided based on temperature readings within the dryer system, as described in Applicant's patent application Ser. No. 63 / 333,284, entitled "Temperature-Based Monitor and Control of a Compressed-Gas Dryer," filed April 21, 2022, which is incorporated herein by reference in its entirety. Such a system can provide cheaper, faster, and "bullet-proof" monitoring of such attributes.

[0081] 7A and 7B show schematic diagrams of some of the internal components of an exemplary dryer 10, including a pressure vessel 11 into which a regeneration zone is provided with an inlet port 25 and an outlet port .

[0082] FIG. 7C shows a schematic top-down view of each zone of an exemplary dryer 10, such as that shown in FIGS. 7A and 7B or FIGS. 1-6, each of which includes a drying zone 12, a regeneration zone 13, and an optional cooling zone 29. In the embodiment of FIG. 7C, the regeneration zone 13 extends approximately 90° of a circle defining a cylindrical pressure vessel or drum 14, with the beginning or origin of the circle beginning at the position labeled 0° and the regeneration zone extending to the position labeled 90°. Thus, in the case where the regeneration zone extends 90° of a circle defining a cylindrical pressure vessel or drum, the regeneration zone occupies approximately one-quarter of the volume defining the cylindrical pressure vessel or drum. Of course, the regeneration zone 13 can extend across a portion of the pressure vessel or drum that is greater than or less than 90°. For example, the regeneration zone 13 can extend anywhere between 10° and 270° of a circular cross-section around the axis of the cylindrical pressure vessel or drum. In embodiments, the regeneration zone extends over 180° of a circular cross-section around the axis of the cylindrical pressure vessel or drum, such that the regeneration zone occupies approximately half of the volume of the cylindrical pressure vessel or drum. Typically, the regeneration zone 13 extends over 45° to 135° of a circular cross-section around the axis of the cylindrical pressure vessel or drum. More typically, the regeneration zone 13 extends over 75° to 105° (e.g., about 90°) of a circular cross-section around the axis of the cylindrical pressure vessel or drum.

[0083] If present, cooling zone 29 typically extends over 5° to 45° of a circular cross-section about the axis of the cylindrical pressure vessel or drum. More typically, cooling zone 29 extends over 10° to 30° of a circular cross-section about the axis of the cylindrical pressure vessel or drum. More typically, cooling zone 29 extends over 10° to 20° of a circular cross-section about the axis of the cylindrical pressure vessel or drum. Typically, cooling zone 29 extends over about 15° of a circular cross-section about the axis of the cylindrical pressure vessel or drum, for example, extending between the portions labeled 90° and 105° as shown in FIG. 7C.

[0084] The drying zone 12 extends around the remaining arc length of the circle not covered by the regeneration zone or the combination of the regeneration and cooling zones. In the example shown in FIG. 7C, the drying zone extends the remaining 255° of the cross-sectional circle around the axis of the cylindrical pressure vessel or drum. Also shown in FIG. 7C, the temperature in the drying zone 12 (otherwise known as the adsorption zone (ADS)) can average approximately 60°C. The temperature in the drying zone 12 can more typically range from 20°C to 80°C. The temperature in the cooling zone 29 can also range from 20°C to 80°C. In comparison, the temperature in the regeneration zone (REG) 13 can be significantly higher (e.g., up to 150°C) because the regeneration gas or air provided through inlet 25 is at a higher temperature than the compressed gas or air being dried in the drying zone.

[0085] In the embodiment according to FIG. 2, a second control signal 102 can be provided to control the opening (and thus the pressure drop) across the venturi ejector 21. The control unit or controller 100 can be further configured to determine the application of additional control signals 103 or 105, such as for the aftercooler 65 or process cooler 91, as shown in FIGS. 5 and 6 and as described in more detail in Applicant's patent application Ser. No. 63 / 333,284, entitled "Temperature-Based Monitor and Control of a Compressed-Gas Dryer," filed April 21, 2022, which is incorporated herein by reference in its entirety.

[0086] In a further embodiment (not shown), the control unit 100 may be further communicatively connected to a remote computer system, e.g., for remote monitoring, control, regulation, and / or software updates, and the data acquired by the control unit 100 and the operating parameters transmitted by the control unit 100 as control signals may be transmitted to the remote computer system or data storage device for further analysis and / or processing.

[0087] In one embodiment, the venturi ejector 21 or other inlet nozzle can be provided with a controllable orifice driven by a drive rod with a gear drive. The pressure drop caused by any particular setting for the controllable orifice in the main flow 18 of gas to be dried can be measured by pressure sensors P1 and P2 in communication with the control unit 100 (to determine the pressure drop dP21). Based on the nozzle inlet temperature (sampled at sensor T1) and this pressure drop dP21, the control unit 100 determines the control signal 101 to be applied to the driver 114. Based on these and other inputs, additional control signals 102, 103, and 105 can also be determined and sent to the appropriate device being controlled.

[0088] The particular split associated with the regeneration connection line (17, 52, 53, 77, or 97) is determined at least in part by the position of the controllable opening in the Venturi ejector or other nozzle 21, since this setting determines the pressure drop and therefore the suction experienced by the regeneration partial flow 19. In this manner, the flow of the regeneration split stream can be controlled. With a relatively smaller nozzle opening, a relatively higher percentage of the flow is diverted through the regeneration loop, such that a larger regeneration flow can be provided by narrowing the size of the nozzle opening.

[0089] As described above, in each of the embodiments according to FIGS. 1 to 6, a driver device 114 is provided to rotate the drum 14 relative to the rotationally symmetric portion of the pressure vessel 11. The drive means may include a motor (preferably an electric motor). The electric motor may be configured to drive the rotor in the pressure vessel at a speed greater than 0 revolutions per hour (RPH) and less than 100 revolutions per hour (RPH). Typical rotational speeds of the rotor in the pressure vessel are less than 10 RPH, and are approximately 1 to 5 RPH. Such values ​​may refer to average speeds, since it will be clear that the rotor may rotate continuously or may rotate intermittently (i.e., stop / start). The electric motor may have a variable speed controller or may have a start / stop controller. The speed of the electric motor, or whether it is started or stopped, is controlled by a first control signal 101 from the control unit 100.

[0090] The start / stop controller is arranged to switch the motor on and off, thereby providing an adjustable average rotational speed of the drum relative to the rotational symmetry. More specifically, the start / stop controller is preferably provided to switch the motor on and off during continuous operation of the dryer, where, on the one hand, a continuous flow of compressed gas is supplied to the drying zone and dried therein, and, on the other hand, a continuous (partial) flow of compressed gas to be dried is directed to the regeneration zone for regenerating the desiccant. The start / stop controller is economical and has advantages over, for example, frequency control for regulating the rotational speed of an electric motor, and can provide capital or operating cost savings. Moreover, the start / stop controller can be less complex and require less control electronics. Notably, the start / stop controller only needs to switch the motor on and off according to a desired duty cycle (in terms of on / off ratio) to provide a desired average rotational speed of the drum. In addition, the start / stop controller can rotate the drum stepwise relative to the rotational symmetry, for example, precisely moving each time a section corresponding to the size of the regeneration zone (or a part thereof), and then stopping the movement of that section for a given period of time. Another advantage of the start / stop controller is that the range of the average rotation speed is wider than when frequency control is used; in particular, the average rotation speed can be infinitely adjusted from 0 to the maximum speed of the motor.

[0091] 8A and 8B illustrate some examples of start / stop controllers. In FIG. 8A, the average speed is 1 / 3 V max In Figure 8B, the average velocity is 2 / 3 V maxThe duty cycle has a period T. The average speed can be varied by varying the amount of time the motor is on during period T. The average speed can also be varied by keeping the amount of time the motor is on constant and varying the amount of time the motor is off, which means the length of the duty cycle T is variable.

[0092] In another embodiment (which may be included by those described above), a relatively high temperature gas (e.g., air having a relative humidity (e.g., saturated or nearly saturated)) is supplied to the inlet 15 for the gas to be dried. Because the gas is at a relatively high temperature T1, it has a relatively high moisture content, and therefore the dryer drum 14 needs to remove more moisture from the gas, which means more regeneration is required and, therefore, a higher flow rate of regeneration gas. In addition to using the measured temperature T1 to determine the flow rate into the inlet 15, the measured temperature T1 can also be used to determine the moisture load of the gas supplied to the inlet 15. The control unit 100 can control the flow rate of the regeneration flow (split flow for regeneration) based at least in part on T1. For example, as T1 increases, the control unit can increase the flow rate, for example, according to a predetermined table or characteristic control curve. The desired normal operation of the dryer can be monitored by feedback provided by measurements of a pressure dew point sensor at the outlet 16.

[0093] In another embodiment (which may be included by those described herein), if the regeneration flow rate varies (e.g., to maintain the pressure dew point within a certain range), it may be desirable to adjust the cooling of the exiting regeneration flow 19 and / or the rotational speed of the drum 14 depending on the regeneration flow rate. A measurement of the regeneration flow rate can be obtained by measuring the pressure drop across the Venturi ejector 21 or other inlet nozzle. The control unit 100 can, for example, control the flow rate of cooling water flowing through the cooling device 20 to cool the exiting regeneration flow, or the flow rate of cooling water flowing through the cooling device 91 to cool the junction (the regeneration flow and the feed flow of the gas to be dried) so that more cooling is performed when the regeneration flow rate increases, thereby avoiding a situation where an increase in the regeneration flow rate causes too little cooling. In conjunction with this, or independently, the control unit 100 can control the rotational speed of the drum 14 according to the regeneration flow rate to optimize the ratio between the two. In this way, the control unit can take into account the useful life of the desiccant and adjust the drum speed accordingly.

[0094] T1 can be based on the mixture provided in the embodiments of Figures 2 to 6, where the partial flow for regeneration is returned to the main line 18 via a connecting line 19 for the supply flow of compressed gas to be dried. This can be done by a controllable device such as a Venturi ejector 21 or other controllable nozzle device to create a pressure difference and to maintain the split flow for regeneration.

[0095] The various illustrated configurations for the dryer system are merely exemplary. It will be recognized that the present concepts for setting the rotational speed of a dryer rotor based on a determined flow rate of gas into the dryer can be incorporated into a variety of dryer systems. Examples of additional dryer systems that can be modified to incorporate such concepts are described in U.S. Pat. Nos. 10,286,357; 10,478,771; 2,332,631; U.S. Patent Application Publication No. 2003 / 0163929; and CN111821823, each of which is incorporated by reference herein in its entirety.

[0096] Example FAD Calculation Rotational speed (typically measured in revolutions per hour) is a determining factor in dryer performance and efficiency because it determines how long the rotor is "in-duty" in the drying zone and how much regeneration time the rotor is given. The optimal, most efficient, or balanced speed maintains the rotor in-duty for the optimal amount of time while providing sufficient time for regeneration. While the drying and regeneration zones share the same pressure vessel and thereby have the same rotational speed, a balance must be determined or calculated to identify the most efficient or optimal rotational speed. The present inventors have discovered that the rotational speed at which the rotor should rotate can be determined primarily, or even solely, based on temperature readings at the nozzle inlet and the pressure drop across the venturi ejector or other nozzle. Such a control mechanism advantageously does not require information about the RPM or load at which the compressor supplying the compressed gas is operating.

[0097] In either case, the controller controls the rotational speed of the rotor to rotate at a set speed selected between the MAX and MIN speeds. As shown in Figure 9, the controller can default to an intermediate reference speed REF. Adjustment or control of this initial reference speed can be done using a calculated free air discharge (FAD) (where data regarding compressor speed is not available), or can be done without the need to use complex calculations such as those in U.S. Patent No. 6,527,836.

[0098] As an example, the FAD calculation can be obtained based on the following geometric, calculated, and measured inputs and steps:

[0099]

number

[0100] [Table 1]

[0101] As an example, the air density ρ is 1188 g / m 3 The nozzle inlet diameter may be 128 mm and the nozzle outlet diameter may be 53 mm.

[0102] In step 1, the density of the air or other gas at the inlet is determined (e.g., calculated) based on the temperature (T) as measured at the nozzle inlet, as well as the measured pressure P [bar (a)] at the nozzle inlet and the standard density of the gas (ρ).

[0103] In step 2, from the calculated density of the air or other gas, the mass flow rate of the air or other gas is determined (e.g., calculated) based on the ρ density calculated in step 1, the measured pressure drop (ΔP) across the nozzle, and the geometric and other parameters set forth in step 2. For example, C is the flow coefficient (often assumed to be 1), ε is the expansibility coefficient (often assumed to be 1), d is the diameter at the exit for the venturi ejector 21 or other inlet nozzle, and β is the diameter ratio (Dout / Din) for the venturi ejector or other nozzle.

[0104] If C and ε can each be assumed to be 1, the formula for step 2 becomes:

[0105]

number

[0106] can be simplified to where d_out is the diameter at the exit for the venturi or other nozzle; dP is the pressure drop across the venturi or other nozzle; ρ1 is the density of the gas at the inlet; β is the diameter ratio (Dout / Din) for the venturi or other nozzle.

[0107] With the mass flow rate QM determined in step 2, the volumetric flow rate or free air delivery [FAD] can then be determined using the formula in step 3, which is simply dividing the mass flow rate (QM) by the standard density (ρ) of the air or other gas and converting to 1 / s by multiplying by 1000.

[0108] Using the calculated FAD value of the compressed gas being introduced into the drying zone of the dryer, controller 100 can determine at what speed driver 114 should rotate drum 14 of dryer system 10. Advantageously, such calculation or determination does not require knowledge of what RPM or load compressor 60 is running at. This is particularly advantageous when the dryer and compressor may be from different manufacturers, or when such communication may otherwise be impractical.

[0109] The correlation between the determined FAD value and the rotor rotational speed can be determined according to a pre-determined table, characteristic control curve, or algorithm. By way of example, the FAD flow rate can typically range up to 4000 l / s (although higher values ​​are possible). More typical values ​​are often in the range of 100 l / s to 1500 l / s.

[0110] Some exemplary FAD calculations are shown below.

[0111] [Table 2]

[0112] [Table 3]

[0113] [Table 4]

[0114] As shown above, FAD calculations are highly accurate (e.g., within 3%, 2%, or even 1% of the actual flow rate) when compared to actual reference measurements. Thus, such FAD calculations present a simple and efficient method for determining flow rate, and from such, what speed the dryer rotor should be rotated, providing efficient operation of the dryer system even when communication with a compressed gas source (e.g., a compressor) may not be possible or practical.

[0115] It is important to note that the set speed of the dryer rotor is based solely on temperature and pressure drop data obtained from the dryer system. The speed is not determined by other parameters believed or considered in the known art (compressor speed, but also humidity, room temperature, altitude, environmental pressure, etc., among others). This has been found by the inventors to provide a particularly robust, efficient, simple, and accurate control mechanism for effectively controlling the rotational speed of a dryer system.

[0116] Although described primarily in the context of measurements taken at the inlet to the drying zone of the dryer system, various temperature, pressure, or mass flow measurements can be taken elsewhere in the system (e.g., at the drying zone outlet, the regeneration zone inlet, the regeneration zone outlet, or other locations). From such measurements, the flow rate at such locations can be determined, and using a mass balance, the flow rate into the drying zone can be determined therefrom. Such alternatives are within the contemplated scope of the present disclosure. Additionally, while in the primarily described embodiments, a venturi is present at the inlet to the drying zone, other nozzles, flow combining devices, or mechanisms can be used to combine the various flows and determine the flow rate at this location. Such alternatives are within the contemplated scope of the present disclosure. That is, while a venturi or other nozzle may be particularly well suited to determining flow rate, other types of gas flow instrumentation or measurement techniques can alternatively or additionally be used (e.g., including, but not limited to, Coriolis mass flow meters, thermal flow meters, ultrasonic flow meters, rotameters, optical flow meters, etc.). Indeed, a variety of sensors and techniques can be used to determine flow rate.

[0117] Embodiments of the present disclosure can include or utilize, among other things, a special-purpose or general-purpose computer system or computing system within or alternatively in communication with control unit or controller 100, which includes computer hardware (e.g., one or more processors 150 and system memory 160). Controller 100 can be relatively close to pressure vessel 11 and driver 114 and can receive hardwired or wireless signals from and send hardwired or wireless signals to other components of the dryer system. Alternatively, controller 100 can be located remotely from the other components of the dryer system and can receive signals from the other components of the dryer system (including one or more temperature or pressure sensors providing temperature or pressure data indicative of one or more temperatures or pressures within the system) and send signals to the other components of the dryer system via a network (e.g., a local area network (LAN), a wide area network (WAN), the Internet, or some other network).

[0118] Embodiments within the scope of the present disclosure also include physical and other computer-readable media for carrying or storing computer-executable instructions and / or data structures. Such computer-readable media can be any available media that can be accessed by a general-purpose or special-purpose computer system. Computer-readable media that store computer-executable instructions and / or data structures are computer storage media. Computer-readable media that carry computer-executable instructions and / or data structures are transmission media. Thus, by way of example, embodiments of the present disclosure can include at least two distinctly different types of computer-readable media: computer storage media and transmission media.

[0119] Computer storage media are physical storage media that store computer-executable instructions and / or data structures. Physical storage media include computer hardware, such as RAM, ROM, EEPROM, solid-state drives (“SSD”), flash memory, phase-change memory (“PCM”), optical disk storage, magnetic disk storage, or other magnetic storage devices, or any other hardware storage devices that can be used to store program code in the form of computer-executable instructions or data structures, which program code can be contained within or accessed and executed by controller 100, a general-purpose computer system, or a special-purpose computer system to implement the disclosed functionality of the present disclosure.

[0120] Transmission media can include networks and / or data links, which can be used to carry program code in the form of computer-executable instructions or data structures and which can be accessed by general-purpose or special-purpose computer systems. A "network" can be defined as one or more data links that enable the transport of electronic data between computer systems and / or modules and / or other electronic devices. When information is transferred or provided to a computer system over a network or another communications connection (either hardwired, wireless, or a combination of hardwired or wireless), the computer system can view the connection as a transmission medium. Combinations of the above should also be included within the scope of computer-readable media.

[0121] Furthermore, upon reaching the various computer system components, program code in the form of computer-executable instructions or data structures may be automatically transferred from transmission media to computer storage media (or vice versa). For example, computer-executable instructions or data structures received over a network or data link may be buffered in RAM in a network interface module (e.g., a "NIC") and then ultimately transferred to computer system RAM and / or to less volatile computer storage media in the computer system. Thus, it should be understood that computer storage media may be included among computer system components that also utilize (or even primarily utilize) transmission media.

[0122] Computer-executable instructions may include, for example, instructions and data that, when executed by one or more processors, cause a general-purpose computer system, special-purpose computer system, or special-purpose processing device to perform a certain function or group of functions. Computer-executable instructions may be, for example, binaries, intermediate format instructions such as assembly language, or even source code.

[0123] The present disclosure of the present application can be practiced in network computing environments with many types of computer system configurations, including, but not limited to, personal computers, desktop computers, laptop computers, message processors, handheld devices, multiprocessor systems, microprocessor-based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, mobile phones, PDAs, tablets, pagers, routers, switches, and the like. The present disclosure can also be practiced in distributed system environments in which both local and remote computer systems, which are linked through a network (either by hardwired data links, wireless data links, or a combination of hardwired and wireless data links), perform tasks. As such, in a distributed system environment, a computer system can include multiple constituent computer systems. In a distributed system environment, program modules can be located in both local and remote memory storage devices.

[0124] The present disclosure of this application may also be practiced in a cloud computing environment. A cloud computing environment may be distributed, but this is not required. When distributed, a cloud computing environment may be distributed internationally within an organization and / or may have components owned across multiple organizations. For purposes of this specification and the claims that follow, "cloud computing" is defined as a model for enabling on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services). The definition of "cloud computing" is not limited to any of the many other benefits that may be obtained from such a model when properly deployed.

[0125] Cloud computing models can consist of a variety of attributes (e.g., on-demand self-service, broad network access, resource pooling, rapid scalability, and scalable services), can be offered in a variety of service models (e.g., Software as a Service (“SaaS”), Platform as a Service (“PaaS”), and Infrastructure as a Service (“IaaS”)), and can be deployed using different deployment models (e.g., private cloud, community cloud, public cloud, and hybrid cloud).

[0126] Some embodiments, such as cloud computing environments, may include a system including one or more hosts, each capable of running one or more virtual machines. During operation, the virtual machines emulate an operational computing system that supports an operating system and possibly one or more other applications as well. In some embodiments, each host includes a hypervisor that emulates virtual resources for the virtual machines using physical resources abstracted from the virtual machine's view. The hypervisor also provides proper isolation between the virtual machines. Thus, from the perspective of any given virtual machine, the hypervisor provides the illusion that the virtual machine is interfacing with physical resources, even though the virtual machine only interfaces with the appearance of physical resources (e.g., virtual resources). Examples of physical resources include processing power, memory, disk space, network bandwidth, media drives, and the like.

[0127] Certain terms are used throughout the specification and claims to refer to particular methods, features, or components. As one skilled in the art will understand, different people may refer to the same method, feature, or component by different names. This disclosure does not intend to distinguish between methods, features, or components that differ in name but not function. The figures are not necessarily drawn to scale. Certain features and components herein may be shown on an exaggerated scale or in somewhat schematic form, and some details of conventional elements may not be shown or described for the sake of clarity and conciseness.

[0128] Although various exemplary embodiments have been described in detail herein, those skilled in the art will readily appreciate in light of the present disclosure that many modifications are possible in the exemplary embodiments without substantially departing from the concepts of the present disclosure. Accordingly, any such modifications are intended to fall within the scope of the present disclosure. Similarly, while the disclosure herein contains many specific examples, these specific examples should not be construed as limiting the scope of the present disclosure or the scope of the appended claims, but merely as providing information regarding one or more specific embodiments that may fall within the scope of the present disclosure and the appended claims. Any described features from the various disclosed embodiments can be used in combination. In addition, other embodiments of the present disclosure can be devised that fall within the scope of the present disclosure and the appended claims. Each addition, deletion, and modification to the embodiments that falls within the meaning and scope of the claims is intended to be encompassed by the claims.

[0129] Certain embodiments and features may have been described using a set of upper numerical limits and a set of lower numerical limits. It should be recognized that ranges including any two value combinations (e.g., any lower value with any upper value, any two lower values, and / or any two upper values) are contemplated unless otherwise indicated. Certain lower limits, upper limits, and ranges may appear in one or more claims below. Any numerical values ​​are designated "about" or "approximately" a value and take into account experimental error and variation that would be expected by one of ordinary skill in the art. When terms such as "about," "approximately," or "substantially" are used in connection with a stated amount, value, or condition, it can be interpreted to mean an amount, value, or condition that deviates by less than 20%, less than 10%, less than 5%, less than 1%, less than 0.1%, or less than 0.01% of the stated amount, value, or condition.

[0130] The present disclosure provides various examples, embodiments, and features, which should be understood as being combinable with other examples, embodiments, or features described herein unless expressly stated otherwise or are mutually exclusive.

[0131] In addition to the above, further embodiments and examples include the following.

[0132] 1. A compressed gas dryer system comprising: a compressed gas source providing compressed gas to be dried; a regeneration gas source providing regeneration gas; a pressure vessel defining a drying zone and a regeneration zone, the drying zone having an inlet portion and an outlet portion, wherein the compressed gas to be dried is received into the drying zone through the inlet portion and the dried compressed gas exits the drying zone through the outlet portion, and the regeneration zone having an inlet portion and an outlet portion, wherein the regeneration gas is received into the regeneration zone through the inlet portion and the regeneration gas exits the regeneration zone through the outlet portion; and a driver configured to drive rotation of a rotor associated with the pressure vessel in a predetermined rotational direction, wherein the compressed gas dryer system is configured to determine a flow rate of the compressed gas to be dried; and the compressed gas dryer system includes a controller configured to set the rotational speed of the rotor based on the determined flow rate of the compressed gas to be dried.

[0133] 2. The compressed gas dryer system according to any one of paragraphs 1 and 3 to 17 below, or a combination of one or more thereof, wherein the compressed gas dryer system includes a venturi or other nozzle, and the determination of the flow rate of the compressed gas is made using measurements taken at the venturi or other nozzle.

[0134] 3. The compressed gas dryer system according to any one of paragraphs 1-2 and 4-17 below, or a combination of one or more thereof, wherein the compressed gas dryer system includes a venturi or other nozzle associated with an inlet to the drying zone, the compressed gas supply to be dried passes across the venturi or other nozzle as it enters the drying zone, and the system is configured to determine a flow rate across the venturi or other nozzle.

[0135] 4. A dryer system according to any one of 1 to 3 and 5 to 17 below, or a combination of one or more of them, wherein the flow rate of the compressed gas to be dried is measured or determined at the inlet.

[0136] 5. A dryer system as described in any one of paragraphs 1 to 4 above and paragraphs 6 to 17 below, or a combination of one or more of them, wherein the flow rate of the compressed gas to be dried is measured or determined using measurements taken at one or more of the following: an inlet to the drying zone, an outlet of the drying zone, upstream from the inlet to the drying zone, downstream from the outlet of the drying zone, an inlet to the regeneration zone, or an outlet of the regeneration zone, or a combination thereof.

[0137] 6. A dryer system according to any one of paragraphs 1 to 5 above and paragraphs 7 to 17 below, or a combination of one or more thereof, wherein the flow rate is determined based on the temperature and pressure of the compressed gas at the inlet and the pressure drop across a venturi or other nozzle.

[0138] 7. The dryer system of any one of 1 to 6 above and 8 to 17 below, or a combination of one or more thereof, wherein the rotational speed of the rotor is set without CAN or other communication provided from a compressor generating the stream of compressed gas.

[0139] 8. A dryer system according to any one of 1 to 7 above and 9 to 17 below, or a combination of one or more of them, wherein the rotor rotation speed is set to a value between 1 RPH and 5 RPH.

[0140] 9. The dryer system according to any one of 1 to 8 above and 10 to 17 below, or a combination of one or more thereof, wherein the venturi or other nozzle associated with the inlet section includes a venturi.

[0141] 10. A dryer system as described in any one of paragraphs 1 to 9 above and paragraphs 11 to 17 below, or a combination of one or more thereof, wherein the venturi or other nozzle associated with the inlet section includes at least one of a pitot tube, a keel probe, or other sensor for measuring pressure in the venturi or other nozzle or pressure drop across the venturi or other nozzle associated with the inlet section.

[0142] 11. The dryer system of any one of paragraphs 1-10 and 12-17 below, or a combination of one or more thereof, wherein the flow rate through a venturi or other nozzle associated with the inlet section is determined by determining the density of the gas at the inlet section, by determining the mass flow rate of the gas based on the pressure drop across the venturi or other nozzle, and by determining the volumetric flow rate therefrom.

[0143] 12. The dryer system according to claim 11, wherein the density of the gas at the inlet is determined based on the pressure and temperature at the inlet.

[0144] 13. The density of a gas at the inlet is determined using the following formula:

[0145]

number

[0146] 13. The dryer system of claim 12, wherein P [bar (a)] is the pressure at the venturi or other nozzle inlet; T [°C] is the temperature at the venturi or other nozzle inlet; and ρ is the density of the gas at standard conditions.

[0147] 14. The mass flow rate of a gas across a venturi or other nozzle is determined using the equation:

[0148]

number

[0149] 14. The dryer system of any one of claims 11 to 13, or a combination of one or more thereof, wherein C is a flow coefficient; ε is an expansibility coefficient; d is a diameter at the exit for the venturi or other nozzle; Δp is a pressure drop across the venturi or other nozzle; ρ is a density of the gas at the inlet; and β is a diameter ratio (Dout / Din) for the venturi or other nozzle.

[0150] 15. The mass flow rate of a gas across a venturi or other nozzle is determined using the equation:

[0151]

number

[0152] 14. The dryer system of any one of claims 11 to 13, or a combination of one or more thereof, wherein d_out is the diameter at the exit for the venturi or other nozzle; dP is the pressure drop across the venturi or other nozzle; ρ1 is the density of the gas at the inlet; and β is the diameter ratio (Dout / Din) for the venturi or other nozzle.

[0153] 16. The volumetric flow rate [FAD] is determined using the formula below:

[0154]

number

[0155] wherein QM is the mass flow rate of the gas across the venturi or other nozzle; and ρ0 is the density of the gas at standard conditions.

[0156] 17. The dryer system of any one of 1 to 16 above, or a combination of one or more thereof, wherein the compressed gas source is a compressor and the regeneration gas source is a portion of the compressed gas stream output by the compressor.

[0157] 18. A method for setting a rotational speed of a rotor in a compressed gas dryer system, the method comprising: providing a compressed gas dryer system including: a compressed gas source providing compressed gas to be dried; a regeneration gas source providing regeneration gas; a pressure vessel defining a drying zone and a regeneration zone, the drying zone having an inlet portion and an outlet portion, wherein the compressed gas to be dried is received into the drying zone through the inlet portion and the dried compressed gas exits the drying zone through the outlet portion, and the regeneration zone having an inlet portion and an outlet portion, wherein the regeneration gas is received into the regeneration zone through the inlet portion and the regeneration gas exits the regeneration zone through the outlet portion; and a driver configured to drive rotation of a rotor provided in the pressure vessel in a predetermined rotational direction, the method also comprising the steps of determining a flow rate of the compressed gas to be dried to be provided to the compressed gas dryer system; and setting the rotational speed of the rotor based on the determined flow rate of the compressed gas to be dried.

[0158] 19. The method of any one of paragraphs 18 and 20 to 35 below, or a combination of one or more thereof, wherein the compressed gas dryer system includes a venturi or other nozzle, and the determination of the flow rate of the compressed gas is made using measurements taken at the venturi or other nozzle.

[0159] 20. A method as described in any one of paragraphs 18-19 and 21-35 below, or a combination of one or more thereof, wherein the compressed gas dryer system includes a venturi or other nozzle associated with an inlet to the drying zone, and the compressed gas source to be dried passes across the venturi or other nozzle as it enters the drying zone, and the method includes determining a flow rate across the venturi or other nozzle.

[0160] 21. A method according to any one of paragraphs 18 to 20 and paragraphs 22 to 35 below, or a combination of one or more of them, wherein the flow rate of the compressed gas to be dried is measured or determined at the inlet of the drying zone.

[0161] 22. The method of any one of paragraphs 18 to 21 and paragraphs 23 to 35 below, or a combination of one or more of them, wherein the flow rate of the compressed gas to be dried is measured or determined using measurements taken at one or more of the following locations: an inlet to the drying zone, an outlet from the drying zone, upstream from the inlet to the drying zone, downstream from the outlet from the drying zone, an inlet to the regeneration zone, or an outlet from the regeneration zone, or a combination thereof.

[0162] 23. The method of any one of paragraphs 18-22 and 24-35 below, or a combination of one or more of them, wherein the flow rate is determined based on the temperature and pressure of the compressed gas at the inlet to the drying zone and the pressure drop across a venturi or other nozzle.

[0163] 24. The method of any one of 18 to 23 and 25 to 35 below, or a combination of one or more of them, wherein the compressed gas source is a compressor and the regeneration gas source is a portion of the compressed gas stream output by the compressor.

[0164] 25. The method of any one of or a combination of one or more of paragraphs 18-24 and 26-35 below, wherein the rotational speed of the rotor is set without CAN or other communication provided from a compressor generating the stream of compressed gas.

[0165] 26. The method according to any one of 18 to 25 and 27 to 35 below, or a combination of one or more of them, wherein the rotor rotation speed is set to a value between 1 RPH and 5 RPH.

[0166] 27. The method of any one of 18-26 and 28-35 below, or a combination of one or more of them, wherein the venturi or other nozzle associated with the inlet of the drying zone comprises a venturi.

[0167] 28. The method of any one of paragraphs 18-27 and paragraphs 29-35 below, or a combination of one or more thereof, wherein the venturi or other nozzle associated with the inlet of the drying zone includes at least one of a pitot tube, keel probe, or other sensor for measuring pressure or pressure drop across the venturi or other nozzle associated with the inlet of the drying zone.

[0168] 29. The method of any one of paragraphs 18-28 and 30-35 below, or a combination of one or more of them, wherein the flow rate through a venturi or other nozzle associated with an inlet to the drying zone is determined by determining the density of the gas at the inlet to the drying zone, by determining the mass flow rate of the gas based on the pressure drop across the venturi or other nozzle, and by determining the volumetric flow rate therefrom.

[0169] 30. The method according to claim 29, wherein the density of the gas at the inlet of the drying zone is determined based on the pressure and temperature at the inlet.

[0170] 31. The density of a gas at the inlet is determined using the following formula:

[0171]

number

[0172] 31. The method according to claim 30, wherein P [bar (a)] is the pressure at the venturi or other nozzle inlet of the drying zone; T [°C] is the temperature at the venturi or other nozzle inlet; and ρ0 is the density of the gas at standard conditions.

[0173] 32. The mass flow rate of a gas across a venturi or other nozzle is determined using the equation:

[0174]

number

[0175] 32. The method of any one of claims 29 to 31 above, or a combination of one or more thereof, wherein C is the flow coefficient; ε is the expansibility coefficient; d is the diameter at the exit for the venturi or other nozzle; Δp is the pressure drop across the venturi or other nozzle; ρ is the density of the gas at the inlet; and β is the diameter ratio (Dout / Din) for the venturi or other nozzle.

[0176] 33. The mass flow rate of a gas across a venturi or other nozzle is determined using the equation:

[0177]

number

[0178] 33. The method of any one of claims 29 to 32 or a combination of one or more thereof, wherein D_out is the diameter at the exit for the venturi or other nozzle; dP is the pressure drop across the venturi or other nozzle; ρ1 is the density of the gas at the inlet; and β is the diameter ratio (D_out / Din) for the venturi or other nozzle.

[0179] 34. The volumetric flow rate [FAD] is determined using the formula below:

[0180]

number

[0181] 34. The method of any one of claims 29 to 33, or a combination of one or more thereof, wherein QM is the mass flow rate of the gas across the venturi or other nozzle; and ρ is the density of the gas at standard conditions.

[0182] 35. The method of any one of 18 to 34 above, or a combination of one or more of them, wherein the compressed gas source is a compressor.

[0183] 36. A hardware storage device having stored thereon computer-executable instructions which, when executed by one or more processors of a computing system, configure the computing system to perform the methods described in any one of 18-35 or a combination of one or more of them.

[0184] 37. A method for setting the rotational speed of a rotor of a compressed gas dryer system, the method comprising the steps of determining a flow rate of compressed gas to be dried provided to the compressed gas dryer system; and setting the rotational speed of the rotor of the compressed gas dryer system based on the determined flow rate of compressed gas to be dried.

[0185] 38. A hardware storage device having stored thereon computer-executable instructions which, when executed by one or more processors of a computing system, configure the computing system to perform the method of 37 above. [Explanation of symbols]

[0186] 10 Hair dryer 11 Pressure vessels 12 Dry Zone 13 Regeneration Zone 14 Drums 15 Entrance 16 Exit section 17 Connection Lines 18 Main Line 19 Connection Lines 20 Recycled Cooler 21 Venturi ejector, nozzle 25 Entrance 26 Exit section 29 Cooling Zone 51 Partial Flow 52 First Partial Flow 53 Second partial flow 54 Heating Devices 60 Compressed Gas Supply Source 61 First compression stage 62 Second compression stage 63 Intercooler 64 Heat exchanger 65 Aftercooler 67 Regenerative Gas Supply Source 77 Connection Lines 91 Process Cooler 97 Connection Lines 100 Controller, control unit 101 Control Signal 102 second control signal 103 Additional Control Signals 105 Additional Control Signals 114 Driver 121 Driver 150 processors 160 Memory Storage 170 Output Interface 180 Input Interface 1000 Compressed Gas Equipment 1100 Compressor 1200 Dryer System P1 pressure sensor P2 pressure sensor dP21 Pressure drop ΔP pressure drop T1 temperature sensor X rotation axis

Claims

1. a compressed gas source providing compressed gas to be dried; a regeneration gas source providing regeneration gas; A pressure vessel defining a drying zone and a regeneration zone, the drying zone having an inlet and an outlet, the compressed gas to be dried being received into the drying zone through the inlet and the dried compressed gas exiting the drying zone through the outlet; a pressure vessel, the regeneration zone having an inlet and an outlet, the regeneration gas being received into the regeneration zone through the inlet and the regeneration gas exiting the regeneration zone through the outlet; a driver configured to drive rotation of a rotor associated with the pressure vessel in a predetermined rotational direction; 1. A compressed gas dryer system configured to determine a flow rate of a compressed gas to be dried, comprising: A compressed gas dryer system including a controller configured to set a rotational speed of the rotor based on the determined flow rate of the compressed gas to be dried.

2. 10. The dryer system of claim 1, wherein the compressed gas dryer system includes a venturi or other nozzle, and wherein the determination of the flow rate of the compressed gas is made using measurements taken at the venturi or other nozzle.

3. 10. The dryer system of claim 1, wherein the compressed gas dryer system includes a venturi or other nozzle associated with the inlet to the drying zone, the compressed gas supply to be dried passes across the venturi or other nozzle as it enters the drying zone, and the system is configured to determine a flow rate across the venturi or other nozzle.

4. 10. The dryer system of claim 1, wherein the flow rate of the compressed gas to be dried is measured or determined at the inlet.

5. 10. The dryer system of claim 1, wherein the flow rate of the compressed gas to be dried is measured or determined using measurements taken at one or more of the inlet to the drying zone, the outlet of the drying zone, upstream from the inlet to the drying zone, downstream from the outlet of the drying zone, the inlet to the regeneration zone, or the outlet of the regeneration zone, or a combination thereof.

6. The dryer system of claim 1 , wherein the rotational speed of the rotor is set without CAN or other communication provided from a compressor generating the stream of compressed gas.

7. 10. The dryer system of claim 1, wherein the flow rate is determined based on the temperature and pressure of the compressed gas at the inlet and the pressure drop across the venturi or other nozzle.

8. 8. The dryer system of claim 7, wherein the venturi or other nozzle associated with the inlet includes at least one of a pitot tube, a keel probe, or other sensor for measuring pressure at or a pressure drop across the venturi or other nozzle associated with the inlet.

9. 10. The dryer system of claim 1, wherein the flow rate through the venturi or other nozzle associated with the inlet section is determined by determining a density of the gas at the inlet section, by determining a mass flow rate of the gas based on a pressure drop across the venturi or other nozzle, and by determining a volumetric flow rate therefrom.

10. The dryer system of claim 9 , wherein the density of the gas at the inlet is determined based on a pressure and a temperature at the inlet.

11. The density of the gas at the inlet is determined using the formula: [Equation 1] where P [bar(a)] is the pressure at the venturi or other nozzle inlet; T [°C] is the temperature at the inlet of the venturi or other nozzle; ρ ０ 11. The dryer system of claim 10, wherein: is the density of the gas at standard conditions.

12. The mass flow rate of the gas across the venturi or other nozzle is determined using the following equation: [Equation 2] where C is the flow coefficient; ε is the expansibility coefficient; d is the exit diameter for the venturi or other nozzle; Δp is the pressure drop across the venturi or other nozzle; ρ １ is the density of the gas at the inlet; 10. The dryer system of claim 9, wherein β is the diameter ratio (Dout / Din) for the venturi or other nozzle.

13. The mass flow rate of the gas across the venturi or other nozzle is determined using the following equation: [Equation 3] where d_out is the diameter at the exit for the venturi or other nozzle; dP is the pressure drop across the venturi or other nozzle; ρ １ is the density of the gas at the inlet; 10. The dryer system of claim 9, wherein β is the diameter ratio (Dout / Din) for the venturi or other nozzle.

14. The volumetric flow rate [FAD] is determined using the following formula: [Equation 4] where QM is the mass flow rate of the gas across the venturi or other nozzle; ρ ０ 10. The dryer system of claim 9, wherein: is the density of the gas at standard conditions.

15. 10. The dryer system of claim 1, wherein the compressed gas source is a compressor and the regeneration gas source is a portion of the compressed gas stream output by the compressor.

16. 1. A method for setting the rotational speed of a rotor in a compressed gas dryer system, the method comprising: Providing a compressed gas dryer system, the compressed gas dryer system comprising: a compressed gas source providing compressed gas to be dried; a regeneration gas source providing regeneration gas; a pressure vessel defining a drying zone and a regeneration zone, the drying zone having an inlet and an outlet, the compressed gas to be dried being received into the drying zone through the inlet and the dried compressed gas exiting the drying zone through the outlet, the regeneration zone having an inlet and an outlet, the regeneration gas being received into the regeneration zone through the inlet and the regeneration gas exiting the regeneration zone through the outlet; a driver configured to drive rotation of a rotor provided within the pressure vessel in a predetermined rotational direction; determining a flow rate of compressed gas to be dried provided to the compressed gas dryer system; setting a rotational speed of the rotor based on the determined flow rate of the compressed gas to be dried; A method comprising:

17. 17. The method of claim 16, wherein the compressed gas dryer system includes a venturi or other nozzle, and the determination of the compressed gas flow rate is made using measurements taken at the venturi or other nozzle.

18. 17. The method of claim 16, wherein the compressed gas dryer system includes a venturi or other nozzle associated with the inlet of the drying zone, the compressed gas supply to be dried passing across the venturi or other nozzle as it enters the drying zone, and the method includes determining a flow rate across the venturi or other nozzle.

19. 20. A hardware storage device having stored thereon computer-executable instructions that, when executed by one or more processors of a computing system, configure the computing system to perform the method of claim 16.

20. 1. A method for setting the rotational speed of a rotor in a compressed gas dryer system, the method comprising: determining a flow rate of compressed gas to be dried provided to the compressed gas dryer system; setting the rotational speed of the rotor of the compressed gas dryer system based on the determined flow rate of the compressed gas to be dried; A method comprising:

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