69results about "Material condensation" patented technology

The invention discloses an object-oriented non-condensable gas-containing vapor condensation visualization experiment device. The device mainly comprises a steam supply system, an air supply system, other gas supply systems, a cooling water system, a visualized experimental body and a data acquisition system. Steam and a non-condensable gas component are produced by the steam supply system, the air supply system and the other gas supply systems. A main gas supply pipe is connected to an experimental cavity and is provided with an electric valve. The electric valve can adjust an opening degreeaccording to the negative feedback of the pressure in the experimental cavity to control the steam flow. Cooling water enters an experimental pipe section through a flowmeter under the action of a water pump, is subjected to heat exchange in the experimental pipe section and then is returned into a constant temperature water bath through a water return pipe. Before the experiment, a vacuum systemrealizes a high vacuum environment in the experimental chamber. The device realizes continuous measurement, analysis and visual observation of the condensation phenomenon under different steam pressures, different subcooling degrees, different non-condensable gas components and contents, and different surface structural characteristics.

The invention discloses an experimental apparatus for visualizing sulfuric acid vapor condensation and deposition, which comprises a circulating coolant tank, an aluminium plate, a condensing copper plate, light sources, an observation cover, a high-speed camera, a computer, a data acquisition board and a temperature control heating rod for controlling the temperature of coolant in the circulating coolant tank. The condensing copper plate is located upon the aluminium plate, the bottom opening of the observation cover is fixed on the condensing copper plate, the side of the condensing copper plate is provided with a plurality of recesses in which thermocouples are embedded, the inside of the aluminium plate is provided with a coolant passage, each of the left side, right side and top side of the observation cover is of a transparent structure, the front side and rear side of the observation cover are respectively provided with a vapor inlet and a vapor outlet, the light sources are aimed at the left side and right side of the observation cover, and the high-speed camera is aimed at the top side of the observation cover. The system can conveniently and visually research the condensation and deposition characteristics of sulfuric acid vapor by visualization.

The invention discloses a condensation heat transfer transient measurement device and method based on thermochromic liquid crystals, which belong to the field of condensation experiment measurement. The measurement device comprises an environment cavity, a heat transfer measurement module and a data acquisition system, wherein the environment cavity provides a stable and visual steam condensationenvironment; the heat transfer measurement module is used for realizing transient non-intrusive measurement of condensation heat transfer and comprises a test surface, a back thermochromic liquid crystal coating, a side thermochromic liquid crystal coating, a transparent cold conduction block, a transparent water cooling plate, a transparent heat insulation layer and a cooling water heat insulation layer; and the data acquisition system is used for acquiring, recording and analyzing images and data. According to the device, the transient temperature distribution of the transparent cold conduction block and the test surface is obtained through the color development change of the thermochromic liquid crystal coatings in the condensation process, then the condensation heat flux density and the supercooling degree are calculated, and quantitative analysis and visualization can be conducted on the average or local condensation heat transfer transient characteristics on the surfaces of different working conditions and different characteristics.

The invention relates to a device for evaluating internal condensation characteristic of an enhanced heat transfer pipe. The device mainly comprises a steam system, a test section, a cold water takingsystem and a data acquisition system, and can evaluate the local condensation heat transfer and pressure drop characteristics of various kinds of steam or mixed gas in different enhanced heat transfer pipes. The steam system comprises a boiler, a precooler, an air compressor, a gas storage tank, a dryer, a gas heater and a static mixer, and can provide pure-component and multi-component steam orair-containing mixed gas needed by the test. The test section comprises a straight pipe measuring section, a condensation section, a measuring section and an observation section which are connected with one another sequentially; an inlet is connected with the steam system; and an outlet is connected with a gas and liquid separator. The two ends of an outer sleeve pipe of each of the precooler andthe test section are connected with one set of water cooling system in parallel. The internal heat transfer coefficient of the enhanced pipe is acquired through a thermal resistance separation method,and basis is provided for thermodynamic design of an efficient pipe shell type condenser.

System and methods for determining a non-condensable gas parameter relating to the amount of non-condensable gas within a variable flow rate fluid flow containing both non-condensable gas and condensate are disclosed. An apparatus may include a measurement tube for receiving the fluid flow and arranged such that the fluid flow through the measurement tube comprises alternating sections of non-condensable gas and condensate; a flow sensor for generating a flow rate signal relating to the flow rate of the fluid flow in the measurement tube; a phase sensor for monitoring over time the alternating sections of non-condensable gas and condensate flowing through the measurement tube and arranged generates a phase signal characteristic of the said sections monitored; and a non-condensable gas determining unit configured to determine a non-condensable gas parameter relating to the amount of non-condensable gas in the fluid flow based on the flow rate signal and phase signal. A related method for determining a non-condensable gas parameter is disclosed also.

The invention relates to a device and a method for testing condensate water formation. The device is used for testing the minimum difference value of surface temperature of a tested sample and given gas temperature when condensate water is formed on the surface of the tested sample by gradually reducing temperature of the tested sample in the given atmosphere environment (atmosphere includes gas temperature, humidity, components and pressure intensity), and the device is further used for testing the maximum duration of keeping condensate-water-free state on the surface of the tested sample under the circumstance that temperature of the surface of the tested sample and the given atmosphere conditions are determined. The invention particularly relates to application verification of a material and a mechanical product and service reliability evaluation, in particular to the method for measuring limit temperature difference when the condensate water is formed on bare surface due to temperature difference between the material or the product and the experiment environment in the simulation test environment with controllable temperature, humidity, atmosphere and pressure intensity or evaluating service reliability of the material or the product and the testing device.

The invention discloses a visual microenvironment constant-temperature and constant-humidity box for interface heat transfer and mass transfer research. A temperature sensor placement hole and a temperature and humidity air supply inlet are formed in the left side wall of an upper cover; a humidity sensor placement hole, a temperature and humidity air supply outlet and an infrared window are formed in the right side wall of the upper cover; the temperature and humidity air supply inlet and the temperature and humidity air supply outlet are connected with constant-temperature and constant-humidity box pipelines; the bottom edges of the front side wall and the rear side wall of the upper cover are provided with cold and hot fluid thermal insulation pipe U-shaped clamping grooves; a microscopic observation cover plate is arranged on a top plate of the upper cover; a reserved microscope lens hole is formed in the cover plate; a thermocouple and a humidity sensor are mounted in the box; a table is arranged on a bottom plate in the box; a thermal insulation pipe is arranged in the table to convey cold and hot fluids; the thermal insulation pipe penetrates through the cold and hot fluid thermal insulation pipe U-shaped clamping grooves; and a clamping groove mounting experiment flat plate is arranged at the upper part of the table. According to the box, the liquid drop condensation and crystallization processes under the influence of temperature and humidity in the interface heat transfer and mass transfer process can be observed in real time.

The invention belongs to the fields of equipment and a method used in atmospheric physics and artificial influence weather research, and particularly relates to a water drop freezing nucleus measuringdevice and an experimental method. The water drop freezing nucleus measuring device comprises a condensation plate, a nanometer superhydrophobic coating, a supporting body, a CCD camera and a microcomputer, wherein the supporting body is arranged on the condensation plate; the supporting body and the condensation plate together define an experimental chamber; the supporting body is provided witha protective gas inlet formed in one side of the experimental chamber and is provided with a protective gas outlet in the other side of the experimental chamber; the nanometer superhydrophobic coatingis arranged on the condensation plate and is positioned on the contact surface of the condensation and the supporting plate; the CCD camera is arranged at the upper end of the supporting body and ispositioned at the upper end of the experimental chamber; the CCD camera is connected with the microcomputer; the microcomputer can acquire information stored in the CCD camera; the condensation plateis connected with the microcomputer; the microcomputer can control cooling of the condensation plate and can accurately acquire the temperature change of the condensation plate. The measuring accuracyand precision of the water drop freezing nucleus can be effectively improved.

An analyser for collecting and analysing a breath condensate is disclosed. The analyser comprises a housing and a cartridge device (10). The device comprises a condensation zone (12) to condense exhaled breath from a subject and cooling means operably connected to the condensation zone (12). The device includes further discrete regions (13) for detection of analyte and measurement of analyte. The condensation zone (12) has a fluid exit connecting the condensation zone (12) to the discrete regions (13). The analyser includes a mouthpiece which is provided with a plurality of chambers configured to cause a change of 90° in the direction of the exhaled breath in order to trap saliva aerosols.

The invention relates to a method (200) and an apparatus (110) for determining a concentration of aerosol particles (112) in a carrier gas (114), in particular for examining atmospheric aerosols (118) or as aerosol particle detector in process gases or in clean air rooms. The method (200) here comprises the steps:a) provision of an aerosol (118) which has aerosol particles (112) in a carrier gas (114) comprising at least one condensable component;b) introduction of at least part of the aerosol (118) into a chamber (120) of a pressure-rated vessel (116), wherein the chamber (120) is delimited by at least one wall (128), wherein the at least one wall (128) adjoining the chamber (120) is set to a temperature which is above a saturation temperature of at least one condensable component;c) subsequent removal of part of the aerosol (118) from the chamber (120), as a result of which a decrease in pressure in the chamber (120) occurs, as a result of which the at least one condensable component condenses at least partly on the aerosol particles (112); andd) determination of a concentration of aerosol particles (112) in the carrier gas (114) during removal of the part of the aerosol (118) from the chamber (120).The invention can be suitable, in particular, for examining atmospheric aerosols, in particular aerosol particles, but can also be used as aerosol particle detector in process gases or in clean air rooms.

A cartridge device (10) for collecting and analysing a breath condensate is disclosed. The device (10) comprises a condensation zone (12) to condense exhaled breath from a subject and cooling means operably connected to the condensation zone (12). The device includes further discrete regions (13) for detection of analyte and measurement of analyte. The condensation zone (12) has a fluid exit connecting the condensation zone (12) to the discrete regions (13).

The invention discloses an experimental facility capable of implementing visualization of condensation of the inside and outside of a steam tube. The experimental facility mainly comprises a steam supply system, a cooling water system, a vacuum system, a visualization experimental body and a data acquiring system. A gas supply main tube is connected with a vacuum cavity or an experimental tube section through a four-way valve, and an exhaust main tube is arranged at the rear of the cavity, and is connected with an aftercooler and a condensation tank. The aftercooler provides a cold source fromconstant-temperature water bath. A cooling water branch line enters the experimental tube section or the vacuum cavity via a flowmeter under the effect of a water pump, after heat exchange, the cooling water branch line returns to the constant-temperature water bath from a water return main tube, and the other branch line enters a tube side of the aftercooler under the effect of the water pump, and then returns to the constant-temperature water bath after heat exchange. Before an experiment, a high vacuum environment in the vacuum cavity or the experimental tube section is realized by the vacuum system. By cooperation of a front four-way valve and a rear four-way valve of the vacuum cavity, condensation of the inside of the tube or condensation of the outside of the tube can be continuously measured and analyzed and visually detected by the device under different steam pressures, different degrees of supercooling and different surface structural characteristics.

Provided is an experimental device for simulating an interaction between femtosecond lasers and cirrocumulus. The device comprises a femtosecond laser device, a lens, a low-temperature cold cabinet, a temperature and humidity detection device, an aerosol generator, a scanning electromobility particulate particle size spectrometer, a digital camera and a beam collecting device, wherein femtosecond laser pulses are focused by the lens to enter an ultra-low temperature high-humidity cavity, femtosecond laser pulse filamentation is conducted in the cavity, accordingly the interaction between laser filaments and simulated cirrocumulus is studied, cloud droplets in the cavity are led to phase change, and processes of moisture condensation and sedimentation are induced. The device simulates the temperature and humidity environment of the cirrocumulus precisely, is simple in structure, safe and convenient to operate and low in price, is suitable for studying and analyzing the phenomenon that the cirrocumulus which is rich in ice crystals interacts with the lasers so that the water condensation and sedimentation can be generated, and is also suitable for analyzing and studying the interaction study between other cloud-mist conditions and the lasers.

The invention discloses an experimental device for testing the law of stream condensation in heavy oil reservoir conditions. The experimental device comprises a steam generation filling pipeline, a filling pipeline for auxiliary production fluid and a condensation chamber; the steam generation filling pipeline and the filling pipeline for the auxiliary production fluid are respectively connected with the condensation chamber; the steam generation filling pipeline and the filling pipeline for the auxiliary production fluid are parallelly connected into the filling pipeline to be connected withthe condensation chamber; an experimental core with saturated formation water and heavy oil is arranged on the condensation installation wall. The experimental core is controlled by the interference of external temperature on the condensing mounting wall, which is consistent with the simulated actual formation core temperature; meanwhile, the temperature and pressure in a condensing chamber are controlled to stimulate real environmental conditions and parameters in actual strata; finally according to requirements of experimental research, steam is injected into the condensing chamber alone ormixed with steam and one or more auxiliary production fluids, and a variety of experimental comparison of technical results is achieved.

The invention belongs to the field of detection on physical and chemical characteristics of petroleum products, and particularly relates to a reduced-pressure micro-distillation system for biomass-based blended fuel. The reduced-pressure micro-distillation system comprises a distillation device, a vacuumizing device, a cooling device and a recycling device. The distillation device is individually isolated by a partition plate and comprises a distillation flask, the bottom of the distillation flask is matched with a clamp table, a heater is arranged on the top of the clamp table and clings to the bottom of the distillation flask, the distillation flask is communicated with a sample bottle via a feed pipe with a pump, and the top of the distillation flaks is communicated with a distillation head. The reduced-pressure micro-distillation system has the advantages that the reduced-pressure micro-distillation system is simple in structure and high in external interference resistance, distillation range data of the biomass-based blended fuel can be quickly and accurately measured by the reduced-pressure micro-distillation system, and vapor pressure data of the fuel can be obtained by the reduced-pressure micro-distillation system.

The invention discloses a method for detecting sulfur dioxide and nitrogen oxides in a high-moisture-content flue gas, and relates to the technical field of air pollutant detection. The method comprises the following steps: (1) sampling of flue gas: connecting an exhaust gas generated after burning of a boiler with three sampling tubes through a flue gas sampler in series, and temporarily storingin the three sampling tubes; (2) determination of moisture content of flue gas; (3) preparation of absorption liquid; (4) determination of nitrogen oxide content; determination of sulfur dioxide content; (6) result accounting. The method has the advantages of improving analysis efficiency and saving detection time.

The invention relates to the technical field of LNG tanks, and in particularly to a cold inspection test device and method for an insulating layer of an LNG marine tank, and the cold inspection test device for the insulating layer of the LNG marine tank comprises the following parts of a low temperature medium container used to storage a low temperature medium having a boiling point less than or equal to minus 163 DEG C; a first branch, of which the inlet end is communicated with the low temperature medium container, and the outlet end is communicated with the LNG tank, wherein the first branch is provided with a vaporizer and a first regulating valve, the vaporizer is used to vaporize a liquid low temperature medium into a gas low temperature medium, and the first regulating valve is communicated with the output end of the vaporize to control the transmission of the gas low temperature medium flowing in the first branch; and a second branch, of which the inlet end is communicated withthe low temperature medium container, and the outlet end is communicated with the LNG tank to transmit the liquid low temperature medium to the LNG tank, wherein the second branch is provided with asecond regulating valve used to control the transmission of the liquid low temperature medium flowing in the second branch. The cold inspection test device and method provided by the invention facilitate the technical personnel to effectively detect the insulating layer of the LNG tank.

The invention belongs to the technical field of gas condensation, and particularly relates to a visual detection device and method for gas condensation heat exchange characteristics. The visual detection device comprises a gas distribution unit, a condensation unit, a refrigeration unit and a data acquisition unit, wherein the gas distribution unit is connected with the condensation unit, the refrigeration unit provides cooling capacity for the condensation unit, and the data acquisition unit acquires temperature information and image information of the condensation unit. The visual detection device captures condensation mode pictures and videos and meanwhile achieves collection of temperature and liquid amount data so as to achieve calculation of the heat exchange coefficient. Undue condensation of the high-boiling-point gas at the flow control position can be effectively prevented, and the condensation process of the gas can be deeply understood through videos and picture data shot at multiple angles on the front face and the side face and heat exchange coefficient changes correspondingly obtained in real time; the side rotary high-frequency switching light source can realize multi-angle adjustable light quantity supply to meet the light source requirement of the image capture equipment.

The invention belongs to the field of detection on physical and chemical characteristics of petroleum products, and particularly relates to a reduced-pressure micro-distillation system for biomass-based blended fuel. The reduced-pressure micro-distillation system comprises a distillation device, a vacuumizing device, a cooling device and a recycling device. The distillation device is individually isolated by a partition plate and comprises a distillation flask, the bottom of the distillation flask is matched with a clamp table, a heater is arranged on the top of the clamp table and clings to the bottom of the distillation flask, the distillation flask is communicated with a sample bottle via a feed pipe with a pump, and the top of the distillation flaks is communicated with a distillation head. The reduced-pressure micro-distillation system has the advantages that the reduced-pressure micro-distillation system is simple in structure and high in external interference resistance, distillation range data of the biomass-based blended fuel can be quickly and accurately measured by the reduced-pressure micro-distillation system, and vapor pressure data of the fuel can be obtained by the reduced-pressure micro-distillation system.

The invention provides an apparatus (100) and a method for preparing distillation measurement of a liquid, and a liquid analysis system. The device has: a device having: a housing; a heater (101), wherein one orifice plate (103, 203a) selected from a set of standardized orifice plates (203a, 203b, 203c, 203d) can be placed on the heater, and the heater is designed to heat a container (105) which contains a liquid (107) and is placed on the orifice plate (103), in order to carry out a standardized test in order to determine the evaporation properties of the liquid; in particular, an electricalmoving system (110) which is designed to move a heater (101) and to interrupt a further movement of the heater (101) when a pressing force (F) of an orifice plate (103) placed on the heater (101) against a container (105) reaches a threshold value. By means of the device, operation errors are avoided, the orifice plate can be accurately positioned on the flask without errors, and the glass flask is prevented from being damaged due to the action of too high force transmitted from the lower portion through the orifice plate.

The invention discloses a deicing method which is applied to an ice maker. The ice maker comprises an evaporation temperature sensor for detecting the temperature of an ice tray and a condensation temperature sensor for detecting the condensation temperature. The method comprises the following steps: acquiring an evaporation temperature of an ice tray working environment for a certain number of times according to a first condensation temperature after acquiring a deicing program starting signal, wherein the evaporation temperature is acquired through the evaporation temperature sensor; and outputting a deicing termination operation signal when the difference between the highest temperature and the lowest temperature in the obtained set number of evaporation temperatures is smaller than a threshold value. The deicing time node is more accurate, the ice production of the ice maker is improved, and energy is saved.

The invention discloses a method for thermal analysis and evaluation of a multi-feature point double-sample cup for inoculation of molten iron in vermicular graphite cast iron, which includes collecting double-sample cups in front of the furnace for thermal analysis and cooling curves of inoculated molten iron in the production of vermicular graphite cast iron, and extracting the inoculated Multiple groups of feature points on the cooling curve of molten iron thermal analysis; bring the extracted multiple groups of feature points into the pre-calibrated inoculum index calculation model for calculation, and obtain the inoculum index calculation value; combine the obtained inoculation index calculation value with the pre-calibrated The inoculation effect index section range is compared, and the inoculation effect of vermicular graphite cast iron is evaluated according to the inoculation effect index section range of the inoculation index calculation value. The invention can make the evaluation of the inoculation effect of the vermicular graphite cast iron molten iron more reasonable and accurate, provide adjustment basis for the dynamic adjustment of the inoculation state in the production process, achieve a good evaluation effect, and ensure the quality of the cast iron molten iron. It also has a certain evaluation effect on the inoculation effect of cast iron molten iron in other graphite forms.

The invention discloses a high-speed axially rotating heat pipe performance testing device and a working method thereof, which relate to the technical field of rotating heat pipe experiments, can avoid the use of a slip ring device, and accurately measure the working fluid inside the heat pipe under high-speed operating conditions temperature. The invention includes: a rotating device, a heating device, a cooling device, a wireless temperature measuring device, a rotating heat pipe to be tested, and an experiment stand. The rotating device drives the rotating heat pipe to rotate at high speed. The heating device provides stable and controllable heat flux density to the evaporation section of the heat pipe by means of induction heating. The cooling device sprays and cools the condensing section of the heat pipe. The temperature is measured directly and the measurement result is transmitted to an external receiving device. The invention can simultaneously measure the heat received in the evaporating section of the heat pipe and the heat dissipation in the condensing section, thereby ensuring the accuracy and reliability of the experiment.

The invention relates to testing equipment for black wood. The testing equipment comprises a cooling tank, wherein a discharge opening is formed in the lower end of the cooling tank; a cooling water pipe is arranged on the outer side of the cooling tank; a heating tube is arranged at the upper end of the cooling tank and comprises an inner tube and an outer tube; the inner tube is communicated with the cooling tank; heaters are arranged between the outer tube and the inner tube; a stirrer is arranged in the inner tube and is connected with a rotating motor through a rotating shaft; the rotating motor is arranged on a support of the heating tube; the upper end of the inner tube is connected with a condensing pipe and a screw feeder; the condensing pipe is connected with a condenser; the screw feeder is connected with a hopper. The detecting equipment for the black wood can be used for detecting whether the content of impurities in the black wood reaches the standard or not, so that thequality of a black wood product can be ensured.

The invention discloses an experimental device for testing the law of stream condensation in heavy oil reservoir conditions. The experimental device comprises a steam generation filling pipeline, a filling pipeline for auxiliary production fluid and a condensation chamber; the steam generation filling pipeline and the filling pipeline for the auxiliary production fluid are respectively connected with the condensation chamber; the steam generation filling pipeline and the filling pipeline for the auxiliary production fluid are parallelly connected into the filling pipeline to be connected withthe condensation chamber; an experimental core with saturated formation water and heavy oil is arranged on the condensation installation wall. The experimental core is controlled by the interference of external temperature on the condensing mounting wall, which is consistent with the simulated actual formation core temperature; meanwhile, the temperature and pressure in a condensing chamber are controlled to stimulate real environmental conditions and parameters in actual strata; finally according to requirements of experimental research, steam is injected into the condensing chamber alone ormixed with steam and one or more auxiliary production fluids, and a variety of experimental comparison of technical results is achieved.

The invention discloses a visualization experiment system and device for testing separation characteristics of condensation water and belongs to the technical field of air condition heat exchanger. The system includes a combined air condition system, a condensation water visible testing unit, an air flow measurement unit and a frozen water system. The combined air condition system is used for performing filtration and heat-wet treatment on air in an entrance and then sending the air to a sample machine testing segment so as to meet requirements of experiment conditions. The condensation water visible testing unit is used for utilizing an endoscope for photographing a separation process of condensation water on heat exchange fins of the sample machine testing segment and recording pressure, temperature and humidity of the sample machine testing segment before and after the separation process. The air flow measurement unit is used for utilizing a flow nozzle and an electric micromanometer for testing air flow in the testing experiment condition. The frozen water system is used for utilizing a circulating water pump for conveying frozen water in a constant low temperature water bath into the experiment sample machine so as to take way heat of the sample machine. According to the invention, visible testing and thermo-technical characteristic testing of the separation process of condensation water in a heat exchange channel can be realized conveniently.

The invention belongs to the technical field of crude oil detection devices, and especially relates to an automatic crude oil water content measuring instrument. The automatic crude oil water content measuring instrument comprises a condenser tube, a receiver is arranged under the condenser tube, and a flask is arranged under the receiver. The flask is characterized in that a magnet conductive layer is sintered on the bottom of the flask and the flask is arranged on a high frequency electromagnetic heater. The provided automatic crude oil water content measuring instrument has the advantages that the flask is directly heated, the conventional mode that a flask is heated by a heating body is changed, the heating body does not have any waste heat, thus the heating body does not need to be cooled individually; during the heating process, the oil drop falling is not dangerous, fire and explosion are avoided, the instrument is safe, energy-saving, and environment-friendly; the burst height of oil gas in the condenser tube can be precisely controlled during the sample preparation process, manual intervention is not needed, and the sample burst will never happen.

The invention discloses a wall internal condensate water detection system based on the Internet of Things technology. The system comprises a building external envelope structure, a humidity sensor, a data processing unit and an Internet client, wherein the humidity sensor detects humidity of the maintenance structure outside the building, the data processing unit processes data of the humidity sensor and transmits the processed result to the Internet client through the Internet of Things technology, and a user can carry out real-time monitoring at the Internet client. According to the system, 24-hour all-weather detection of the content of condensed water in the building wall can be realized, guarantee is provided for safety of a building, and defects in the prior art are effectively overcome.

The invention discloses a cold experiment method of a solidification process and belongs to the technical field of continuous casting of steel. The cold experiment method of the solidification processcomprises the steps as follows: firstly, side walls of an experiment tank of an experiment device are heated; hot water in a hot water tank is pumped into a heat exchange tank by a first water pump through a pipeline, and hot water in the heat exchange tank performs heating and heat insulation on a metal plate; when the temperature of the metal plate, the side walls of the experiment tank and a bottom plate is not lower than that of an experiment solution, the experiment solution is poured into the experiment tank; hot water in the heat exchange tank and the pipeline is drained; cold water ina cold water tank enters the heat exchange tank through a pipeline, cold water in the heat exchange tank cools the metal plate, the experiment solution crystallizes and precipitates on the surface ofthe metal plate, and the crystallization process is observed by an observation instrument. The method can simulate crystallization and segregation behaviors of molten steel in the solidification process.

The invention discloses a distillation reflux instrument for detecting volatile matters in food and a sample pretreatment method, and the distillation reflux instrument comprises: a distillation unit which is used for distilling a to-be-treated sample; a heating unit used for providing water vapor for the distillation unit so as to heat the to-be-treated sample; an end point quantification unit for monitoring the amount of fraction produced by the distillation unit; and a control unit used for controlling the on-off of circuits of the distillation unit and the heating unit according to a signal output by the end point quantification unit. The instrument has the advantages of water resource saving, is simple and reliable in test operation, high in automation degree and good in man-machine interaction, can effectively improve the detection efficiency and the detection precision, is suitable for determination of the contents of nitrosamine, cyanide, volatile phenol and the like in organic matters, and has the advantages of novel idea, good safety, sample pollution prevention and high reflux efficiency.