Testing device for atmospheric distillation

Abstract

A test device for atmospheric distillation for the distillation analysis of a liquid sample at atmospheric pressure for improving the prediction of the heating necessary to reach the initial boiling point (IBP) and ensuring that the IBP is observed within certain time constraints irrespective of the sample composition. The sample is monitored by a camera during different heating phases of the test to obtain visual images of the sample, and a computer analyzes the observed image data to adjust the optimal distillation process.

Description

Technical Field

[0001] The utility model provides a device and a method for distilling liquid fuel or petroleum samples under atmospheric pressure, and more specifically, provides a device and a method for automatically distilling such samples under specified conditions. Background Art

[0002] Atmospheric distillation is a method of separating components with different volatilities from a liquid mixture by heating and condensing a liquid sample. Generally, the method involves heating a specified amount of sample in a flask to reach an evaporation phase, then condensing the vapor in a thermostatically controlled tube and recovering the condensate of the vapor in a receiver. The aforementioned test is performed under specific conditions.

[0003] The atmospheric distillation method can be used to determine the boiling range characteristics of petroleum products and liquid fuels. The program for testing these characteristics has been determined. For example, the American Society for Testing and Materials ("ASTM") has published a standard test method for testing the boiling range characteristics of petroleum products and liquid fuels, which is designated as ASTM D86-20b, i.e., a standard test method for distilling petroleum products and liquid fuels at atmospheric pressure (ASTM International, West Conshohocken, Pennsylvania, USA, 2020, www.astm.org). The method is equivalent to other world standards such as ISO3405, IP123, GOST2177 and JISK2254.

[0004] Test apparatus have been developed to perform ASTM D86 and equivalent test procedures manually and automatically. These test apparatuses generally include a round bottom flask with a neck portion extending therefrom, a condenser connected to the neck portion of the flask. The opposite end of the condenser is connected to a receiving container or a collecting flask, and the condenser includes a cooling source, which generally may include a flowing liquid, such as circulating water, but may also include a solid cooling device around the condenser to maintain a temperature gradient therein, such as a Peltier device or other similar thermoelectric cooler. Heat is applied to the flask to start the distillation process, and as the heat increases, the liquid sample begins to boil and the vapor begins to rise to the neck portion of the flask. Once the vapor reaches the cold condenser, the vapor is condensed into a liquid and rolls down along the length of the condenser, where it is collected in a receiver.

[0005] In particular, these standardized distillation apparatuses generally comprise: a heating element; a distillation flask, the neck of which can be closed by means of a fluid-tight plug and which can be connected to a condenser, the fluid-tight plug being provided with a thermometer allowing the temperature of the evaporated vapor to be measured; a collecting cylinder allowing the condensate to be collected and provided with means for measuring the amount of condensate collected in this way as a function of time; and control and regulation means allowing the operating variables of the heating element to be controlled and varied over time, in particular the temperature or the electrical power of this element, in order to obtain distillation parameters according to predefined criteria, in particular the distillation rate and / or time for a specific volume.

[0006] For a specific group of products, the standard specifies, in particular, parameters such as the time elapsed between starting to heat the sample and obtaining the initial boiling point, IBP (i.e. the time when the first drop of condensate is observed in the collecting cylinder), or the time elapsed between the IBP and obtaining the 5% distillation point (i.e. the point at which 5% of the initial volume of the sample has been collected in the collecting cylinder).

[0007] These standards also specify the distillation rate (i.e., the volume of sample or condensate evaporated per unit time during the distillation process) between the 5% distillation point and the point where only 5 mL of sample remain in the distillation flask, or the time elapsed between the point where only 5 mL of sample remain in the distillation flask and the final boiling point FBP (i.e., the end of the distillation).

[0008] The automatic distillation devices operating according to these standards currently proposed commercially implement a method according to which a predetermined amount of the sample to be analyzed (usually 100 mL) is introduced into a distillation flask, the distillation flask is placed on a heating element, it is closed and connected to a condenser, the sample to be analyzed is sorted into the groups defined by the selected standard, then the distillation of the sample to be analyzed is started, the amount of condensate collected in the collecting cylinder, the temperature of the evaporated vapor and the operating variable of the heating element, in particular the temperature or the electrical power of the element, are continuously measured. The values ​​thus measured are sent to a control and regulation member which in turn controls the operating variable of the heating element to directly and automatically obtain the distillation parameters, in particular the distillation rate and / or time according to a specific volume of the selected standard. Automatic distillation thus means at least automatically controlling the heating according to the measured values ​​of the amount of condensate collected in the collecting cylinder, the temperature of the evaporated vapor and the operating variable of the heating element, in particular the temperature or the electrical power of the element.

[0009] As described above, the ASTM D86-20b standard test method can be used to measure many specific characteristics and / or properties of petroleum products or liquid fuel samples specified by the method. Such characteristics and / or properties include the initial boiling point ("IBP"), the 5% distillation point, and the point at which only 5 mL of sample remain in the distillation flask. The IBP is defined as the temperature reading observed at the moment the first drop of condensate falls from the lower end of the condenser. The 5% distillation point is the temperature reading when 5% of the initial volume of the sample has been collected in the collection receiver.

[0010] An important and complex aspect of performing the ASTM atmospheric distillation test involves controlling the heating of the flask to accurately measure the aforementioned characteristics and properties of various petroleum products, especially when the composition of the products varies due to changes in the crude oil source, refining process, blending, or due to contamination. It is also difficult to find the appropriate heating of the flask at the beginning of the test to comply with the time between the initial boiling point and 5% recovery and to maintain the specified distillation rate in the future.

[0011] Initially, the atmospheric distillation test procedure was performed manually. However, over time, automated test devices were developed to facilitate testing and improve accuracy and repeatability. However, with some of these automated test devices, the user must determine the initial power and duration applied, then a second power value will be applied until a uniform distillation rate (ml / mn) can be measured and heating adjustments are initiated to maintain the correct rate. It is rare to obtain a value that meets the standard on the first test, so the test needs to be repeated until a satisfactory value is obtained.

[0012] U.S. Patent No. 8,372,247 (the '247 patent) discloses a prior art automated testing apparatus in which the temperature of a liquid within a flask is measured by an external infrared ("IR") sensor. In particular, the distillation apparatus of the '247 patent includes: a distillation flask, a condenser connected to the distillation flask, a collection cylinder connected to the condenser to collect distillate, a thermometer for indirectly measuring the temperature of a liquid sample present in the distillation flask, a thermometer for directly measuring the temperature of vapor present in the distillation flask, and a heating element and a controller for controlling the heating. A single point measurement (i.e., the temperature of the liquid sample) is used to predict the initial heating of an unknown product. In the prior art, such predictions of the necessary heating to reach the IBP are made by measuring the temperature evolution of the liquid in the distillation flask using a non-contact or external IR sensor. The prediction of the necessary heating prior to the 5% distillation point is based on the temperature of the liquid sample in the distillation flask and the temperature of the vapor at the point where the neck of the distillation flask is connected to the condenser (measured by a standard vapor thermometer). However, these predictions may not always be accurate. After the liquid sample begins to boil and the vapor begins to rise in the flask, the dynamics of the temperature distribution are manifested in the neck portion of the distillation flask. Information about the movement of the vapor during this time delay or gap (i.e., between when the liquid first begins to boil and when the rising vapor column comes into direct contact with the standard vapor thermometer) is currently unmeasurable and therefore unknown. However, if known, this data (e.g., the rate at which the column vapor moves, the evaporation energy of the sample) can provide additional considerations in improving heating adjustments, such as adding or subtracting heat so that IBP can be observed at an earlier time point. In other words, additional measurements of the temperature profile of the rising vapor column will improve the predictability of the necessary heating before IBP and ensure that IBP is observed within the time limits specified by the selected standard because the heating of the sample can be adjusted more quickly (i.e., before the vapor comes into contact with the standard vapor thermometer). The test apparatus of the '247 patent also contributes to high interference levels (e.g., internal reflectivity and emissivity) of various components. For example, there is a high level of radiation reflected from the inner wall of the collimator of the IR sensor monitoring the spherical portion of the distillation flask. In addition, the substrate for the flask exhibits high emissivity, while the IR target area on the distillation flask exhibits low emissivity. These factors cause thermal interference and signal distortion, which affects the reproducibility and accuracy of the test. In addition, in order to apply the necessary corrections to the heating management so that the test procedure is performed under conditions that meet the test standards, the test device described in the '247 patent utilizes an algorithm based on a very large database derived from the temperature of the liquid in the flask and the heating power initially applied. However, this results in a correct test the first time approximately 70%-80% of the time.

[0013] U.S. Patent No. 10,363,495 (the '495 patent) is a potential improvement on the test apparatus described in the '247 patent. The '495 patent discloses a prior art automated test apparatus in which the temperature of the liquid in the flask is measured by a first external IR sensor and a second IR sensor is also included to indirectly measure the temperature of the vapor just at the beginning of the glass column of the flask. However, the technique relies on data collected from a large number of tests lasting several years. With the development and implementation of new types of samples, especially biofuels whose sources are increasingly developed, such use of the database becomes less meaningful. In addition, the technique analyzes the increase in product temperature as a function of the power applied to the heating element in order to determine the specific heat of the sample and thereby identify its type, and since the heat transfer between the heating element and the flask may vary (e.g., imperfect positioning of the flask on the support plate), this calculation may be imperfect or contain errors. The boiling temperature is also taken into account (by slowing down the temperature increase) to help determine the type of sample being tested, but if boiling occurs too late in the time period allowed by the method, there is no longer any possibility of correcting the heating quickly enough.

[0014] Another prior art automated testing apparatus is disclosed in U.S. Pat. No. 8,448,510 (the '510 patent). The testing apparatus of the '510 patent includes an optical system capable of emitting at least one infrared beam directed horizontally through a measuring barrel and cooperating with a linear drive action via a stepper motor that is movable in a vertical translational manner to allow the beam to be aligned with a meniscus of condensate collected in the barrel, thereby allowing the height of the meniscus to be detected. The optical system of the '510 patent includes a dual light shield fixed to a frame that is vertically translated / driven via a stepper motor and a fixed light shield. The dual light shield has two emitter-receiver pairs, each of which is capable of emitting a beam directed horizontally through the measuring barrel, wherein one emitter-receiver pair emits and receives a central beam centered on the measuring barrel for detecting a lower portion of a meniscus of condensate collected in the barrel, and a second emitter-receiver pair emits and receives an eccentric beam offset relative to the central beam and passing between the center and a wall of the measuring barrel for detecting a lower portion of a meniscus of condensate collected in the barrel.

[0015] EP1967268A1 relates to a collar for improving contact and communication between a side branch of a distillation flask and a condenser. EP1967269B1 relates to a device for automatically positioning a heating element relative to a distillation flask.

[0016] EP1967270B1 relates to an apparatus for automatically aligning and positioning a distillation flask so that the distillation flask is maintained in the proper orientation for conducting ASTM D86-20b testing.

[0017] EP 1 967 848 B1 relates to a system for ensuring proper mounting of an insulating plate between a heating element and a distillation flask.

[0018] EP1972378B1 relates to a measuring tube holder for use in distillation testing incorporating a fluorocarbon resin based seal. However, these developments generally relate to the test setup rather than the data capture during the test, as they are not concerned with the measurement of the test sample within the flask during the test.

[0019] Therefore, there is a need for an improved system and method for analyzing a test sample within a flask when conducting ASTM D86-20b testing. Utility Model Content

[0020] The utility model provides a distillation test device and method for automatically distilling a liquid sample under atmospheric pressure, wherein a camera is arranged in the device and method to observe what is happening in a distillation flask. The camera takes visible images. Therefore, the camera is not an IR sensor.

[0021] The utility model controls the heating of the flask according to the analysis of the camera image so as to obtain the time from the first application of heat to the initial boiling point that meets the standards used, the time from the initial boiling point time to the 5% recovery that meets the standards used, and the time from the 5mL residue to the endpoint record that meets the standards used.

[0022] Image analysis also helps to adjust the distillation rate (ml / min) uniformly throughout the test.

[0023] Different phenomena and events during the initial phase of the test when heat is applied can be analyzed and detected on the camera image:

[0024] Ripples appear in the liquid due to the presence of a hot liquid stream moving in the flask;

[0025] Bubbles appear on the walls of the flask;

[0026] Liquid surface agitation;

[0027] Fluid level increases due to expansion;

[0028] The vapor column rises and refluxes due to condensation on the inner wall of the flask; and / or

[0029] The vapor travels toward the condenser tube into the arms of the flask.

[0030] The utility model provides a testing device for distilling a liquid sample under atmospheric pressure, the testing device comprising:

[0031] a flask having a round bottom, a neck portion, and a top opening;

[0032] a stopper for covering the top opening of the flask;

[0033] a heating element in thermal communication with the bottom of the flask for heating the flask;

[0034] a temperature sensor passing through the plug;

[0035] a condenser connected to the flask at one end of the condenser;

[0036] A cooling source surrounding the condenser;

[0037] a receiver in communication with the condenser for receiving a distillate from the condenser;

[0038] a sensor for monitoring the level and / or amount of distillate collected in a receiver during a distillation test,

[0039] a camera positioned to monitor the behavior of the liquid sample within the flask during the distillation test to obtain image data of the liquid sample, preferably image data of the liquid sample and vapor evolved from the liquid sample, and

[0040] An image analysis system for controlling a heating element based on an analysis of image data.

[0041] The utility model also provides a method for automatically distilling a liquid sample under atmospheric pressure, preferably under the conditions specified in a standard test method (such as ASTM D86-20b), regardless of the composition, using the test device of the utility model.

[0042] The test setup includes:

[0043] a flask having a round bottom, a neck portion, and a top opening;

[0044] a stopper for covering the top opening of the flask;

[0045] a heating element in thermal communication with the bottom of the flask for heating the flask;

[0046] a temperature sensor passing through the plug;

[0047] a condenser connected to the flask at one end of the condenser;

[0048] a cooling source surrounding the condenser;

[0049] a receiver connected to the condenser for receiving the distillate;

[0050] a sensor for monitoring the level and / or amount of distillate collected in a receiving vessel during a distillation test,

[0051] a camera positioned to monitor the behavior of the liquid sample within the flask during the distillation test to obtain image data of the liquid sample, preferably the liquid sample and vapor evaporating from the liquid sample, and

[0052] an image analysis system for analyzing the image data and for controlling the heating element based on the analysis of the image data;

[0053] The method comprises the following steps:

[0054] Selecting a group of products to be analyzed as liquid samples;

[0055] Regulate the temperature of condensers and receivers;

[0056] introducing a predefined amount of liquid sample into the automated distillation assembly flask;

[0057] Start the test using the start trigger;

[0058] heating a flask containing a liquid sample using a heating element;

[0059] monitoring the behavior of the liquid sample in the flask during the distillation test using a camera to obtain image data of the liquid sample, preferably image data of the liquid sample and vapor evolved from the liquid sample, and analyzing the image data in an image analysis system;

[0060] detecting the initial boiling of the liquid sample using an image analysis system;

[0061] Use a temperature sensor to measure the temperature of the vapor in the flask;

[0062] regulating heating by controlling a heating element based on an analysis of the image data;

[0063] measuring a recovered volume of a distillate produced from the liquid sample received in a receiver; and stopping heating when the end point of the distillation is reached. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] The following drawings are included to illustrate certain aspects of the present disclosure and should not be considered as exclusive embodiments. Without departing from the scope of the present disclosure, the subject matter disclosed in the present utility model is capable of considerable modifications, combinations and equivalent operations in form and function.

[0065] Figure 1 is a schematic diagram of an exemplary distillation test assembly according to one or more embodiments of the present disclosure.

[0066] Figure 2 An exemplary method according to the present disclosure is shown.

[0067] Figure 3 An alternative schematic diagram of an exemplary distillation test assembly with two cameras according to the present invention is shown.

[0068] Figure 4 An exemplary displacement of vertical lines that may be provided on a backlight and appear on the neck of a flask in accordance with the present disclosure is shown. DETAILED DESCRIPTION

[0069] Figure 1 An exemplary distillation assembly 10 according to one or more embodiments of the present disclosure is shown. In the illustrated example, the distillation assembly 10 includes: a distillation flask 12 having a stopper 18; a temperature measurement system for measuring the temperature of the vapor, such as a thermometer 20; a condenser 22; a cooling source 36; a receiver (also known as a receiving container, such as a collection flask or other receiving glassware) 24; a bottom plate 28 having an opening for placing the distillation flask; a shell 30; and a heating element 26. In the illustrated example, the distillation flask 12 has a bulb or lower circular portion 14 configured to contain a liquid fuel sample 38, and a neck portion 16 extending upward from the lower circular portion 14. The condenser 22 is connected to the neck portion 16 of the distillation flask 12 by a flask side tube 23. The stopper 18 forms a seal at the top of the neck portion 16, thereby sealing the distillation flask 12 from the external environment.

[0070] As shown, a plug 18 is disposed at the upper end of the neck portion 16 and supports a thermometer 20 such that the thermometer 20 is suspended within the neck portion 16. The thermometer 20 extends through the plug 18 via a hole (not shown) in the plug 18 such that a tip 21 of the thermometer 20 is positioned in the neck portion 16 just below where the side tube 23 connects to the neck portion 16 of the distillation flask 12. The thermometer 20 is mounted through the plug 18 so that the thermometer 20 is mechanically centered in the neck 16 of the distillation flask 12 without vapor leakage. Figure 3 and Figure 4 A non-limiting example of a typical centering device for mechanically centering the thermometer 20 in the neck 16 of the distillation flask 12 is shown in ASTM D 1404, the entire contents of which are incorporated herein by reference. The thermometer 20 measures the temperature of the vapor rising from the liquid sample 38 when it comes into direct contact with the front end 21 of the thermometer 20. A cooling source 36 surrounds the condenser 22. A receiver 24 collects the condensate or distillate 40 produced by the distillation process. The thermometer is typically a mercury-in-glass thermometer or an electronic temperature measurement system.

[0071] Typically, a barometer 70 is provided, which is a pressure measuring device capable of measuring the local site pressure with an accuracy of 0.1 kPa (1 mm Hg) or better, located at the same altitude relative to sea level as the device at its location of use, such as a laboratory. The barometer 70 is used to determine the local atmospheric pressure when the distillation assembly 10 is in use.

[0072] The cooling source 36 may include various types of cooling devices, such as a device configured to provide a continuous flow of water or a solid-state cooling device. In the illustrated example, the cooling source surrounds the condenser 22, creating a temperature gradient, wherein the accumulated vapor from the distillation flask 12 condenses and rolls down along the condenser 22 until the condensate 40 drips into the receiver 24. The receiver 24 may take a variety of configurations, including cylindrical, and may have a scale to measure the amount of the collected distillate 40. In some embodiments, one or more sensors 25 may be used to determine the amount of distillate 40 collected in the receiver 24 during the distillation test. The amount of distillate may be a volumetric amount or a weight amount. The temperature of the air surrounding the receiver 24 may be adjusted.

[0073] In the illustrated example, the distillation assembly 10 is configured to observe the liquid sample 38 in the distillation flask 12, and to control the heating of the heating element 26 based on the observation of the liquid sample 38 by the camera 50. The camera 50 communicates wirelessly or via a wired connection (e.g., an Ethernet cable 54) with an image analysis system including a computer 52. The computer 52 may include control and regulation components that allow the operating variables of the heating element to be controlled and varied over time, particularly the temperature or electrical power of the element. Thus, the heating element 26 may communicate with the computer 52 wirelessly or via a wired connection (e.g., an Ethernet cable or other type of cable 56). The computer 52 is configured with software to receive data (i.e., an image of the sample 38) from the camera 52, analyze and interpret this data, and then control the heating element 26 based on the analyzed and interpreted image data so as to obtain distillation parameters, particularly the distillation rate and / or time for a specific volume according to a predefined standard.

[0074] like Figure 1As shown, the computer 52 includes: a microprocessor 60; a memory 62; one or more data / signal inputs 64, for example, for receiving signals from the camera 50 (and / or other sensors (not shown)); and one or more data / signal outputs 66, for example, for sending control signals to control the heating element 26 to adjust the heating of the sample 38. The camera 50 is connected to the computer 52, which has software for analyzing images received from the camera 50 to determine (measure) and record the sample during different stages of the test. The camera 50 observes the sample 38 in the flask throughout the test, such as from the start-up stage of the test to the distillation of the sample 38. When the heating element 26 applies heat to the sample 38 during the test, the computer 52 analyzes what happens to the sample 38.

[0075] The power required at the start of the test can vary. For example, when the test sample is gasoline, a few watts may be required, while when the test sample is diesel, up to several hundred watts may be required. Therefore, the test procedure may generally include applying low power heating and then gradually increasing the heating until the first phenomenon (ripples in the sample 38) detected by analyzing the image data from the camera appears. Then, based on the remaining time to obtain the first drop (IBP), the computer 52 can adjust the heating power to meet the conditions required by the applicable standard.

[0076] Thus, the computer 52 may also be configured to receive data indicative of the level / amount of the condensate 40 in the receiver 24. For example, the computer 52 may communicate with the sensor 25 that monitors the level / amount of the condensate 40 in the receiver 24. After 5% recovery is collected in the receiver 24, the heating power of the heating element 26 is managed by the computer 52 to maintain a uniform distillation rate (ml / min), i.e., the rate at which the receiver is filled.

[0077] The computer 52 is programmed to analyze the image data collected by the camera 50 and can detect phenomena in the test sample 38 based on the differences in the successive images provided by the camera 50. The computer 52 can use some numerical filtering to reduce artifacts. In addition, the image area analyzed can be configured as a function of the observed phenomenon.

[0078] For example, computer 52 may identify the presence of ripples in a liquid due to the presence of a moving stream of hot liquid in a flask by analyzing successive images to detect small differences in the sample, even though the successive images appear very similar due to the relatively slow nature of the phenomenon.

[0079] Regarding the appearance of bubbles on the wall of flask 12, computer 52 can detect the change in the image when the first bubble appears, and can then detect when the bubble remains stable for a certain period of time and how long the bubble remains "stuck" to the flask wall before subsequently rising to the surface.

[0080] With respect to agitation of the sample liquid level, computer 52 may detect changes between images concentrated in the upper region of sample 38 .

[0081] With respect to the increased fluid level due to the expansion, the computer 52 may detect a gradual upward movement of a "fluid churn" phenomenon compared to the previous image.

[0082] About the rise of steam and the reflux caused by condensation on the inner wall of flask 12, computer 52 can detect the change between images focusing on the neck 16 area of ​​flask 12. In addition, this is the reflux phenomenon detected when steam may not be visible (and can be seen visually), and this reflux phenomenon usually occurs at the interface of sample steam and upper air. However, some samples with low boiling point temperature (for example, gasoline or some solvents) do not have this reflux phenomenon, because the temperature of flask 12 is not significantly lower than the temperature of steam so that steam condenses on its wall. In these examples, backlight source 32 can be arranged behind flask 12 and relative to camera 50 (that is, flask 12 is located between camera 50 and backlight source), so that because steam has a different refraction angle from air, steam detection can be performed via computer 52. When observing flask 12, vertical lines can appear on the edge of the neck 16 (it is a glass tube) of flask 12 formed by the wall around flask and become visible. Additionally, in addition to the vertical lines that appear on the edge of the neck portion 16 described above, one or more vertical lines (e.g., black vertical lines) may be provided on the backlight 32 so that the one or more vertical lines are visible through the neck 16 of the flask 12. When viewed, these vertical lines (on the neck 16 and / or backlight 32) appear to shift (or become misaligned) in the presence of sample vapor and no longer align with the lines of the "air" area above, and the computer 52 may detect this change. Thus, the computer 52 may detect vapor using changes in the refractive index of the medium.

[0083] Figure 4An example of how the computer 52 according to some examples can use the refractive index to analyze the camera 50 image is illustrated. In the illustrated example, a pair of vertical lines 402, 404 appear at the edge of the neck 16 of the flask 12, and one or more additional vertical lines 406 can be positioned behind the flask 12 (e.g., on the backlight 32) to be visible through the neck portion 16. During the test, a vapor zone 412 is generated above the sample and below the air zone 410. The air zone 410 and the vapor zone 412 are separated at the boundary 408, and the vapor cannot extend beyond the boundary. When enough vapor is generated to form the vapor zone 412, the vertical lines 402, 404, 406 are laterally offset or become misaligned at the boundary 408, as indicated by the misalignment 414 shown. In other words, the vertical lines 402, 404, 406 in the air zone 410 are not aligned with the vertical lines 402, 404, 406 in the vapor zone 412. Identifying the evolution of misalignment 414 allows determining and detecting the current vapor content, and also determining the change (increase / decrease) in the vapor content. Using this information, for samples with very little or no visible condensation reflux formed on the wall of the flask 12, the vapor / air boundary line in the flask neck 16 can be detected.

[0084] With respect to vapor reaching the condenser tube 22 in the arm 23 of the flask 12, the computer 52 may detect changes in the area of ​​the side arm 23 of the flask 12 between images.

[0085] Figure 1 An example is shown where the camera 50 is positioned to continuously monitor the liquid sample 38 .

[0086] However, if Figure 1 As shown, the camera 50 is typically positioned and oriented to focus on the entire flask 12 (i.e., the camera 50 is positioned to monitor the entire height of the flask 12, rather than being positioned very closely relative to the sample so that portions of the flask 12 are outside the field of view or viewing window 80 of the camera 50) and continuously feeds this image data / information to the computer 52. Thus, the camera 50 may be provided with a wide angle lens and appropriately aimed to capture (record) an image (or video) of the entire flask 12. The entire flask includes the liquid sample 38 within the lower circular portion 14 of the distillation flask 12 and the neck portion 16 of the flask 12 where the vapor is formed. In this way, the entire flask 12 may be located within the field of view 31 of the camera 50. Figure 1 In the illustrated example, the camera 50 is supported to be aligned with the window 31 of the housing 30. The housing 30 may be in the form of a chimney and may have the window 31 formed in one wall thereof. Preferably, the camera 50 is positioned behind the window 31 so as to observe the entire distillation flask 12 through the window 31. In this way, the camera 50 is protected from the heat radiated by the heating element 26 and / or the effects of a fire accident that may occur during testing within the chimney.

[0087] The image analysis system of the test device is also able to detect anomalies during the distillation process, such as smoke formation in the flask or unexpected flask breakage, and activate available safety measures such as alarms.

[0088] Optionally, the test device has a fire detection and extinguishing system, wherein the computer 52 determines whether a fire event is occurring in the chimney and causes the activation of a fire extinguisher in the chimney to extinguish the fire. The fire detection and extinguishing system may also include heat sensors, temperature sensors, and / or smoke sensors (not shown) that communicate with the computer 52 to send data so that the computer 52 can determine whether a fire event is occurring in the chimney (housing 30).

[0089] In addition, the backlight source 32 described above may be disposed within the housing 30, behind the flask 12 and opposite the camera 50. As shown, the backlight source 32 may be positioned behind the flask 12 so that the flask 12 is located between the window 31 and the backlight source 32 to illuminate the flask 12 for monitoring by the camera 50. However, the backlight source may be disposed elsewhere within the housing 30, and / or additional backlight sources may be disposed within the housing 30 in addition to the backlight source 32. Figure 1 Other places than shown.

[0090] Various types of cameras can be used. Camera 50 can be a digital camera including a photodetecting charge coupled device (CCD). However, camera 50 can have different configurations. In one example, camera 50 is a camera with a complementary metal oxide semiconductor (CMOS) sensor, but other technologies can also be used. In some examples, camera 50 has a wide angle lens and / or a lens with an infrared (IR) filter. In some examples, two or more cameras can be used, for example, where one or more additional cameras focus on a specific aspect of the test device, such as a portion of a distillation flask or a sample, etc.

[0091] Figure 3 The modified camera 51 is shown having a second (additional) camera 51. Figure 1 Alternative schematic diagram of an exemplary distillation test assembly. The second camera 51 can communicate with the computer 52 wirelessly or via a wired connection (e.g., Ethernet cable 55) to one or more data / signal inputs 64. The second camera 51 observes the flask neck 16 through the window 33. Figure 3 As shown, both cameras 50, 51 may be oriented horizontally, or both may be tilted at an angle to focus on a portion of the flask 12, or a combination of these two orientations. Figure 3 In the embodiment, the first camera 50 is tilted and the second camera 51 is horizontal. However, if desired, the second camera 51 may be tilted instead and / or the first camera 50 may be horizontal instead.

[0092] Thus, as described herein, the subject matter disclosed in the present invention works by observing the visual effects of heating applied to the sample 38, thereby simulating the manual execution of the test. This enables the first reaction of the sample 38 to heating to be detected earlier than the IR sensor method, thus allowing the computer to adjust the heating earlier and avoid falling into a "too late" situation as may occur in the IR sensor system disclosed by U.S. Patent No. 10,363,495 (the '495 patent). The subject matter disclosed in the present invention is less dependent on the quality of the heat exchange between the heating element 26 and the flask 12, because the important information to know is whether to increase or decrease the heating power. The camera 50 also enables tracking the rise of vapor in the neck 16 of the flask 12, which a device equipped with an IR sensor (such as the device described in the '495 patent) cannot do.

[0093] The use of a camera and the analysis of the images are usually independent of any database. The system works by observing the visual effects of heating on the sample, as an operator would (and sometimes still does) manually.

[0094] The computer 52 controls the heating element 26 based on the analysis of the images obtained by the camera 50. The computer 52 is programmed to analyze the images of the sample 38 as the heating element 26 heats the sample 38. This image analysis helps to adjust the distillation rate (i.e., in ml / min) throughout the test. In particular, the computer 52 can analyze the images of the sample 38 observed by the camera 50 during different stages of the test to determine the appearance of ripples on the surface of the liquid sample 38 due to the presence of the hot liquid flow moving in the flask 12, the appearance of bubbles on the inner wall of the distillation flask 12, the agitation of the liquid level of the sample 38 in the flask 12, the increase in the content of the sample 38 due to expansion, the rise of vapor and the reflux caused by condensation on the inner wall of the flask 12, and / or the arrival of vapor towards the condenser tube 22 to the arms of the flask, etc. For example, during the test phase and after 5 mL of condensate has been recovered in the receiver 24, the computer 52 may measure the distillation rate (i.e., the flow rate (ml / min) of condensate collected into the receiver 24) via the sensor 25, and based on this measurement, the computer 52 may control the heat output of the heating element 26 applied to the distillation flask 12 and the sample 38 therein to keep the distillation seed within specified limits.

[0095] Many petroleum products such as gasoline, kerosene, diesel, etc. are mixtures of hydrocarbons; they are not composed of a single chemical molecule, unlike pure products such as acetone or toluene. For mixed products, the vapor temperature increases as the distillation progresses, with the "lightest" compound vaporizing at the beginning of the test and the "heaviest" compound vaporizing at the end of the test because more heat is required to evaporate. Normally, the compounds evaporate one after the other, producing a gradually increasing temperature curve relative to the recovery %. However, with the emergence of new compounds and biofuels, test operators are increasingly presented with samples that present "holes" in the smooth progress of evaporation due to the significant difference in the boiling points of two adjacent compounds. This occurs when the "lightest" compound has evaporated, but in order to vaporize the next compound, a significant increase in heating power is required. During this period, called the "hesitation point", no more (or less) vapor is produced and the distillation rate slows down. The operator or automated distillation system should anticipate this phenomenon and quickly increase the heat of the flask in order to maintain the target distillation rate. However, if the heating adjustment reaction to the measured reduction in distillation rate occurs too late, because the distillation rate is already outside the standard set parameters, the distillation test fails and needs to be repeated again with a fresh portion of the liquid sample. The present invention provides a solution to avoid this situation.

[0096] When distillation is proceeding at a steady rate, the reflux loop (or vapor) may stabilize slightly above the flask arm 23. The camera 50 monitors this reflux loop (or vapor), and the computer 52 may detect a drop (or decrease) in the position of the reflux loop, and then anticipate a potential decrease in condensate flow early enough to adjust the heating of the heating element 26 (in response to detecting such a drop or decrease in the loop), thus ensuring that the distillation rate (ml / min) remains within the range specified by the standard.

[0097] Method for using the device of the utility model

[0098] See now Figure 2 , flow chart 200 shows the distillation test procedure of the utility model. An unknown liquid sample to be tested is prepared according to the selected distillation standard method (e.g., ASTM D86) and placed in a distillation flask, and the distillation flask is installed in a distillation assembly. If necessary, an automatic analyzer can be used to automatically perform distillation. Test parameters (e.g., the diameter of the support plate of the distillation flask, the condenser and receiver temperatures, etc.) are set according to the selected distillation standard method and the selected product group. The product group includes groups 1-4, which group products based on the characteristics of the product (e.g., distillate type, vapor pressure, expected IBP, etc.), as described in ASTM D86-20b.

[0099] Beginning at block 210, the user first selects a product group to be analyzed. In block 214, a distillation assembly, such as an automatic analyzer, begins adjusting the temperature of the condenser and receiver. Now that the sample has been prepared and the parameters have been set, the distillation process can begin. As shown in block 216, the test or analysis begins. This can be accomplished by pressing a "start" button or other similar start trigger on the distillation assembly.

[0100] The distillation process consists of several stages. Figure 1 as well as Figure 2 In the process flow diagram of the present invention, the liquid sample in the flask 12 is heated while adjusting the heating so that the time interval between the first application of heat and the IBP (initial boiling point) is as specified in the selected test standard, as shown in block 220, while the camera obtains an image of the liquid in the distillation flask and sends the image to the computer for analysis. As described above, this analysis is beneficial for providing early detection of IBP and adjusting the heating between the first application of heat and the IBP (initial boiling point).

[0101] When the IBP is determined, the time and temperature of the IBP are recorded, as shown in block 222 .

[0102] The liquid sample in the flask is then heated while adjusting the heating to provide a time from IBP to 5% recovery as specified in the selected test standard, as shown in block 230, while a camera acquires an image of the liquid in the distillation flask and sends the image to a computer for analysis. As described above, the analysis is useful for adjusting the heating from IBP to 5% recovery.

[0103] When 5% recovery is determined, the time and temperature for 5% recovery are recorded, as indicated at block 232 .

[0104] The liquid sample in the flask is then heated, while the heating is adjusted so that the time from 5% recovery to 5 mL of residue is 4 mL to 5 mL per minute or as otherwise specified in the selected test standard, as shown in block 240, while the camera 50 obtains an image of the liquid in the distillation flask 12 and sends the image to the computer 52 for analysis. As described above, the analysis is beneficial for adjusting the heating from 5% recovery to 5 mL of residue. As described above, the computer 52 analyzes the image data obtained from the camera 50 to detect the phenomenon occurring in the sample 38 in the flask 12, so as to control the heating element 26 based on the occurrence of the phenomenon, thereby maintaining the distillation rate within the test parameters (e.g., the computer 52 analyzes the image of the camera 50 to identify the reflux loop / vapor in the neck 16 of the flask 12, and adjusts the heating to avoid too low a distillation rate).

[0105] When the 5 mL residual is determined, the time and temperature of the 5 mL residual are recorded, as shown in block 242 .

[0106] When the liquid sample 38 continues to be heated, the camera 50 continuously monitors the liquid in the distillation flask 12. This helps to assess the progress of heating and boiling. If the camera 50 and the computer 52 do not observe the indication of sufficient heating or boiling, the heating of the liquid sample continues or increases. However, if it is observed that boiling begins and the image from the camera 50 analyzed by the computer 52 shows that the rate of heating and boiling is higher than the appropriate rate, the heating of the liquid sample is reduced. However, when there is little sample left or no sample 38 evaporates, applying too much heating to the flask 12 may damage the glass of the flask 12, causing the flask 12 to malfunction (breakage) during subsequent testing. Therefore, the computer 52 can analyze the image data from the camera 50 to determine whether any sample 38 remains in the flask 12, thereby determining whether any further (or additional) heating should be applied. For example, when testing is performed on certain types of samples (e.g., Type 4 samples), excess power may be increased to evaporate some of the heaviest residue remaining in flask 12, and camera 50 and computer 52 may be programmed to determine whether such excess power should be increased, and if so, when it should be shut off.

[0107] Also after reaching the IBP, determine whether the collected distillate volume is greater than the control volume. If not, continue to adjust the heating of the liquid sample. If the volume exceeds the control volume, the test proceeds to the later stages of frame 230 and frame 240.

[0108] For later stages, such as blocks 230 and 240, heating control may be switched to a PID (proportional-integral-derivative) control algorithm or similar routine stored in the computer. If desired, this control may be enhanced by having the camera continue to obtain images of the liquid in the distillation flask and the computer analyzing these images to indicate whether boiling is proceeding properly.

[0109] According to the standard (e.g., ASTM D86), there are two time standard limits: (1) the time from the start of the test (heat is applied) to the observation of the first drop of distillate (i.e., IBP) in the collection flask, and (2) the time from IBP to the 5% distillation point (i.e., 5% of the initial volume of the sample is collected as distillate). The present invention improves both of these.

[0110] In one example of the housing 30 of the present invention, the housing 30 includes a plurality of side walls defining an interior in which the flask 12 may be disposed. Here, the housing 30 includes a first wall provided with a window 31 and an opposing wall provided with a backlight source 32, and in this example, the backlight source 32 forms an opposing wall. Here, the housing 30 is a multi-wall structure, so one or more additional walls are provided to define between the backlight wall and the camera window wall. One of these walls may be provided as a door (e.g., a removable panel), which an operator may open and close to access the flask 12. In some examples, the housing 30 is a three-wall enclosure, and in other examples, the housing 30 is a four-wall enclosure, etc.

[0111] In one example, the movable panel has a window portion, the movable panel can be in an upper position to place the window portion in an upper position, and the movable panel can be in a lower position to place the window portion in a lower position.

[0112] Terms of this utility model

[0113] The following clauses describe various aspects of the invention.

[0114] Clause 1. A test apparatus for distilling a liquid sample at atmospheric pressure, the test apparatus comprising:

[0115] a flask having a round bottom, a neck portion, and a top opening;

[0116] a stopper for covering the top opening of the flask;

[0117] a heating element in thermal communication with the bottom of the flask for heating the flask;

[0118] a temperature sensor extending through the plug;

[0119] a condenser, wherein the condenser is connected to the flask at one end of the condenser;

[0120] a cooling source surrounding the condenser;

[0121] a receiver, the receiver being in communication with the condenser for receiving the distillate from the condenser;

[0122] a sensor for monitoring the level and / or amount of the distillate collected in the receiver during a distillation test,

[0123] a camera positioned to monitor the behavior of the liquid sample within the flask during the distillation test to obtain image data of the liquid sample, preferably image data of the liquid sample and vapor evolved from the liquid sample, and

[0124] An image analysis system is provided for controlling the heating element based on an analysis of the image data.

[0125] Clause 2. The testing device of clause 1, wherein the image analysis system comprises a computer.

[0126] Clause 3. The testing apparatus of clause 2, wherein the computer analyzes the image data observed by the camera during different heating phases of a distillation test.

[0127] Clause 4. The testing device of Clause 1, further comprising a base plate for supporting the flask, the base plate having a hole in a center thereof and positioned between the flask and the heating element.

[0128] Clause 5. The test device of Clause 1, wherein the temperature detector passing through the plug comprises a thermometer passing through the plug, the thermometer having a tip extending below the condenser such that the tip is positioned within the neck.

[0129] Clause 6. The testing device of Clause 1, wherein the condenser is removably attached to the neck portion of the flask at one end.

[0130] Clause 7. The testing device of Clause 1, wherein the one or more cameras can be equipped with a wide angle lens and / or a lens with an infrared (IR) filter.

[0131] Clause 8. The testing device of Clause 1, wherein the image analysis system comprises a backlight panel located behind the flask and opposite the camera.

[0132] Clause 9. The test device of clause 1, wherein the backlit panel comprises one or more vertical lines visible to the camera through the neck of the flask to facilitate detection of backflow in the neck by a change in refractive index phenomenon.

[0133] Clause 10. A testing device according to clause 1, wherein the image analysis system comprises a first digital camera and a second digital camera and a computer, wherein the first digital camera and the second digital camera communicate with the computer, wherein the first digital camera is used to monitor a lower portion of the flask including the round bottom, and the second digital camera is used to monitor an upper portion of the flask including the neck.

[0134] Clause 11. A method of automatically distilling a liquid sample at atmospheric pressure, preferably under conditions strictly specified by a standard test method (e.g., ASTM D86-20b), using the test apparatus of any preceding clause, the method comprising the steps of:

[0135] Selecting a group of products to be analyzed as liquid samples;

[0136] regulating the temperature of the condenser and the receiver;

[0137] introducing a predefined amount of said liquid sample into an automated distillation assembly flask;

[0138] Start the test using the start trigger;

[0139] heating the flask containing the liquid sample using the heating element;

[0140] monitoring the behavior of the liquid sample in the flask during a distillation test using the camera to obtain the image data of the liquid sample, preferably the image data of the liquid sample and vapor evolved from the liquid sample,

[0141] analyzing the image data in the image analysis system;

[0142] detecting initial boiling of the liquid sample using the image analysis system;

[0143] measuring the temperature of the vapor in the flask using the temperature sensor;

[0144] regulating the heating by controlling the heating element based on an analysis of the image data;

[0145] measuring a recovered volume of a distillate produced from the liquid sample received in the receiver; and

[0146] Heating was stopped when the end point of the distillation was reached.

[0147] Clause 12. The method according to clause 11, further comprising the step of determining an initial boiling point of the liquid sample.

[0148] Clause 13. The method according to Clause 11, further comprising the step of determining a 5% distillation point of the liquid sample.

[0149] Clause 14. The method of Clause 11, further comprising the step of determining a final boiling point of the liquid sample.

[0150] Clause 15. The method according to Clause 11, further comprising the step of determining the initial boiling point of the liquid sample, the step of determining the 5% distillation point of the liquid sample, and the step of determining the final boiling point of the liquid sample.

[0151] Clause 16. The method of clause 11, wherein the image analysis system detects abnormal conditions during the distillation process, such as smoke formation in the flask or unexpected flask breakage, and activates available safety measures such as an alarm.

[0152] Therefore, the disclosed systems and methods are very suitable for obtaining the mentioned purposes and advantages and the purposes and advantages inherent therein. The specific embodiments disclosed above are only exemplary. It is possible to modify and practice the teachings of the present disclosure in different but equivalent ways that are obvious to those skilled in the art who benefit from the teachings herein. In addition, except as described in the claims below, there is no intention to limit the details of the construction or design shown herein. It is obvious that the specific exemplary embodiments disclosed above can be changed, combined or modified, and all such changes are considered to be within the scope of the present disclosure. The systems and methods disclosed exemplarily herein can be appropriately practiced in the absence of any element not specifically disclosed herein and / or any optional element disclosed herein. Although compositions and methods are described according to "including", "comprising" or "containing" various parts or steps, compositions and methods can also be "essentially composed of various parts or steps" or "composed of various parts or steps". All numbers and ranges disclosed above may be different. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range are specifically disclosed. Specifically, each range of values ​​disclosed herein (in the form of "from about a to about b" or equivalently "from approximately a to b" or equivalently "approximately ab") is understood to list each number and range contained within the wider range of numerical values. Moreover, unless otherwise explicitly and clearly defined by the patentee, the terms in the claims have their ordinary common meaning. In addition, the indefinite articles "a" or "an" used in the claims are defined herein to mean one or more than one of the elements they introduce. If there is any conflict in the use of a word or term in this specification with one or more patents or other documents that may be incorporated herein by reference, the definition consistent with this specification should be adopted.

[0153] The terms "proximal" and "distal" are defined herein relative to a test operator. The term "proximal" refers to a location where an element is closer to a test operator, while the term "distal" refers to a location where an element is farther from a test operator. Additionally, the use of directional terms such as up, down, upper, lower, upward, downward, left, right, etc., are used with respect to the exemplary embodiments as depicted in the accompanying drawings, with an upward or upper direction toward the top of the corresponding drawing, and a downward or lower direction toward the bottom of the corresponding drawing.

[0154] As used herein, the phrase "at least one of..." preceding a series of items (with any items separated by the terms "and" or "or") modifies the list as a whole rather than each member of the list (i.e., each item). The phrase "at least one of..." allows for a meaning that includes at least one of any one of the items, and / or at least one of any combination of the items, and / or at least one of each of the items. For example, the phrase "at least one of A, B, and C" or "at least one of A, B, or C" refers to only A, only B, or only C, respectively; any combination of A, B, and C; and / or at least one of each of A, B, and C.

Claims

1. A test device for atmospheric distillation, characterized in that: Used for distilling liquid samples at atmospheric pressure, the test apparatus comprises: a glass flask having a rounded bottom, a neck portion, and an open top; a stopper for covering the top opening of the flask; a heating element in thermal communication with the bottom of the flask for heating the flask; a temperature sensor extending through the plug; a condenser, wherein the condenser is connected to the flask at one end of the condenser; a cooling source surrounding the condenser; a receiver, the receiver being in communication with the condenser for receiving the distillate from the condenser; a sensor for monitoring the level and / or amount of the distillate collected in the receiver during a distillation test, a digital camera positioned to monitor the behavior of the liquid sample within the flask during the distillation test to obtain sequential images of the liquid sample, a backlight panel located behind the flask and opposite the digital camera, and An image analysis system is provided for controlling the heating element based on analysis of successive images provided by the digital camera.

2. The testing apparatus of claim 1, wherein the digital camera is positioned to monitor the behavior of the liquid sample within the flask during the distillation test to obtain sequential images of the liquid sample and vapors emitted from the liquid sample.

3. The testing device of claim 1, wherein the image analysis system comprises a computer.

4. The testing apparatus of claim 3, wherein the computer analyzes the sequential images observed by the digital camera during different heating phases of a distillation test.

5. The testing device of claim 1, further comprising a base plate for supporting the flask, the base plate having a hole in the center thereof and positioned between the flask and the heating element.

6. The test device of claim 1, wherein the temperature sensor passing through the plug comprises a thermometer passing through the plug, the thermometer having a tip extending below the condenser such that the tip is positioned within the neck.

7. The testing apparatus of claim 1, wherein the condenser is removably attached to the neck portion of the flask at one end.

8. The testing device according to claim 1, wherein one or more of the digital cameras can be equipped with a wide-angle lens and / or a lens with an infrared filter.

9. The test device of claim 1, wherein the backlit panel includes one or more vertical lines visible to the camera through the neck of the flask to facilitate detection of backflow in the neck by a change in refractive index phenomenon.

10. The testing device of claim 1 , wherein the image analysis system comprises a first digital camera and a second digital camera and a computer, wherein the first digital camera and the second digital camera communicate with the computer, wherein the first digital camera is used to monitor a lower portion of the flask including the round bottom, and the second digital camera is used to monitor an upper portion of the flask including the neck.

11. The testing device of claim 1 , wherein the image analysis system is configured to detect abnormal conditions during the distillation process and activate applicable safety measures.

Images