52results about How to "Reduce temperature drop rate" patented technology

The invention discloses a composite phase-change energy storage material for microcapsules and a preparation method thereof. The coating of the microcapsule is made of silicon dioxide, and the core of the microcapsule is made of a phase-change energy storage material, wherein the phase-change energy storage material is a paraffin organic solid-liquid phase-change energy storage material. 0.2 to 0.5 wt.% of dispersed emulsifier, 52.5 to 62.5 wt.% of solvent water, 18.75 to 31.5 wt.% of phase-change energy storage material and 15.5 to 18.75 wt.% of inorganic silica source are matched and put into a reactor for stirring for 5 to 8 hours; the mixture is uniformly dispersed and emulsified at the temperature 3 to 8 DEG C higher than that for solid-liquid phase change; hydrochloric acid aqueous solution catalyst with the pH value of 0.93 to 4.07 or sodium hydroxide aqueous solution catalyst with the pH value of 8.0 to 12.0 is added into the emulsion; the reacting solution is naturally cooled to room temperature and precipitation solution is obtained; the precipitate is washed with the combination of water and petroleum ether, wherein the mass percent of the petroleum ether is 30 wt.%; then the precipitate is washed with deionized water and is filtered, and the product is naturally aired. The invention improves the technology of phase-change energy storage and conservation, and has the function of automatic temperature regulation, favorable physical and chemical stability, crack resistance, flame retardancy, wear resistance and high thermal conductivity.

The invention discloses concrete. The concrete is prepared from the following components of ordinary Portland cement, a mineral admixture, a water reducing agent, medium sand, broken stones, an anti-cracking silicone waterproof agent (FQY) and water, wherein the mineral admixture is prepared from pulverized fuel ash and granulated blast-furnace slag; the fineness modulus of the medium sand is 2.3 to 2.9, and the broken stones are continuous graded broken stone particles of which the particle size is 5 to 25 mm. The novel concrete disclosed by the invention has higher performance index on aspects of crack resistance, leakage prevention, working performance and durability.

The invention discloses a gaseous pollutant multi-point matrix mixed sampling device, a sampling method thereof and a reverse blowing maintenance method. The device comprises a flue gas duct, a plurality of high-temperature sampling probes are uniformly arranged on the outer side of the pipe wall of the flue gas duct along the same section of a pipe, gaseous pollutants are conveyed into a rear-end mixing box by a 180-DEG C high-temperature heat tracing pipe, mixed and then conveyed into an analysis cabinet. The sampling device solves the problems that single-point flue gas sampling is non-representative, a sampling section of an existing sampling device is blocked by dust, and sampling of a sampling end does not meet standards. According to the whole multi-point matrix mixed sampling device, each probe is individually filtered, two-stage filtration is performed, namely, a front feeler lever is provided with a sintered metal filtering screen, middle high-temperature sampling probes are provided with sintered ceramic filter elements, and dust in flue gas is further prevented from entering the pipe.

The invention provides a high-lance-position vacuum refining method based on a coherent jet top lance. The coherent jet top lance is provided with a powder passage located at the center, a main oxygen passage located on the periphery of the powder passage and an auxiliary oxygen passage located on the periphery of the main oxygen passage; and during RH vacuum refining, oxygen enters from the main oxygen passage and the auxiliary oxygen passage to form a main oxygen flow and an auxiliary oxygen flow respectively, powder is injected into molten steel together with the main oxygen flow under the sweeping and protection of the main oxygen flow, the main oxygen flow impacts the molten steel and reacts with carbon in the molten steel to generate carbon monoxide, and carbon monoxide escaping from the molten steel is subjected to secondary combustion with the coherent surrounding accompanying auxiliary oxygen flow to heat a vacuum tank so as to reduce temperature drop of the molten steel. According to the invention, the auxiliary oxygen flow forms the surrounding accompanying flow outside the central supersonic jet flow, so that the expansion and attenuation of the central supersonic jet flow are smaller, the supersonic jet flow is longer, the penetration depth and stirring strength of the oxygen jet flow to a molten bath are increased, a lance position is raised to reduce splashing of the molten steel and slag sticking to a lance head, and the service life is prolonged.

The invention relates to a rolling compaction process based on asphalt mixed material compaction characteristic. The rolling compaction process comprises the following steps: 1) determining the inserting pressing temperature of the asphalt mixed material; 2) determining the final pressing temperature of the asphalt mixed material by a compaction characteristic experimental method; 3) determining the effective rolling compaction time; 4) determining the rolling compaction mode; and 5) determining rolling compaction parameters. The invention provides the rolling compaction process capable of guaranteeing complete compaction of the asphalt mixed material by considering the compaction characteristic of the asphalt mixed material and the temperature field change rule and by reasonably determining the final pressing temperature of the asphalt mixed material and the effective compaction time so as to guarantee that the compaction degree meets the requirements.

The embodiment of the invention provides a refrigerator capable of preventing the upper surface of a middle beam from being frozen, and relates to the technical field of refrigeration equipment. The refrigerator is provided for solving the problem that a lead of a heating device of a middle beam of an existing refrigerator is likely to be affected with cold and damp so as to be aged. The refrigerator capable of preventing the upper surface of the middle beam from being frozen comprises a box body and door bodies used for sealing the box body. The middle beam is arranged at the position of an opening of the box body. The middle beam is of a hollow structure, a heating device is arranged inside the middle beam, and the middle beam is filled with heat insulation materials. The end of the middle beam is in sealed connection with the inner wall of the box body. A lead of the heating device is electrically connected with a control circuit of the refrigerator after penetrating out of the end of the middle beam and the inner wall of the box body. The refrigerator capable of preventing the upper surface of the middle beam from being frozen is used for storing goods at a low temperature.

The invention discloses a composite phase-change energy storage material for microcapsules and a preparation method thereof. The coating of the microcapsule is made of silicon dioxide, and the core of the microcapsule is made of a phase-change energy storage material, wherein the phase-change energy storage material is a paraffin organic solid-liquid phase-change energy storage material. 0.2 to 0.5 wt.% of dispersed emulsifier, 52.5 to 62.5 wt.% of solvent water, 18.75 to 31.5 wt.% of phase-change energy storage material and 15.5 to 18.75 wt.% of inorganic silica source are matched and put into a reactor for stirring for 5 to 8 hours; the mixture is uniformly dispersed and emulsified at the temperature 3 to 8 DEG C higher than that for solid-liquid phase change; hydrochloric acid aqueous solution catalyst with the pH value of 0.93 to 4.07 or sodium hydroxide aqueous solution catalyst with the pH value of 8.0 to 12.0 is added into the emulsion; the reacting solution is naturally cooledto room temperature and precipitation solution is obtained; the precipitate is washed with the combination of water and petroleum ether, wherein the mass percent of the petroleum ether is 30 wt.%; then the precipitate is washed with deionized water and is filtered, and the product is naturally aired. The invention improves the technology of phase-change energy storage and conservation, and has the function of automatic temperature regulation, favorable physical and chemical stability, crack resistance, flame retardancy, wear resistance and high thermal conductivity.

The invention relates to a high-strength corrosion-resistant nickel-based polycrystalline high-temperature alloy and a preparation method thereof. The alloy comprises the following components of, in percentage by mass, 13%-17% of Cr, 15%-20% of Co, 0.1%-0.5% of Ti, 5.0%-5.5% of Al, 3.0%-7.0% of W, less than or equal to 0.5% of Si, less than or equal to 0.5% of Mn, 1.5%-2.0% of Nb, 0.04%-0.07% of Cand the balance Ni. Homogenizing treatment is conducted after smelting is conducted, hot rolling is conducted and finally heat treatment is conducted. The alloy has excellent strength and corrosion resistance, and the tensile yield strength of the alloy at a room temperature and 850 DEG C is higher than 900 MPa and 680 MPa respectively, and the alloy has excellent processing performance and structure stability at the same time.

The invention discloses a ladle furnace (LF) refining steel ladle sealing device and a use method thereof. The LF refining steel ladle sealing device comprises a ladle body and a ladle cover. The bottom edge of the ladle cover and the top edge of the ladle body are sealed and buckled. The ladle cover is provided with one or more wire feeding pipes. When the ladle cover and the ladle body are buckled, the bottoms of the wire feeding pipes are located above molten steel inside the ladle body. When the LF refining steel ladle sealing device is used, the ladle cover is sealed on the ladle body through hoisting equipment, alloy core wires penetrate through the wire feeding pipes, and the wire feeding depth is controlled to be 100-200 mm below the interface of the molten steel. The ladle body is sealed through the ladle cover, so that contact burning of strong deoxidizer and oxygen in air on the steel slag interface is avoided, and loss of the strong deoxidizer is reduced. Contact burning of the alloy core wires and the oxygen is reduced, and the situation that calcium compounds in the molten steel cannot be drained and pollutes the molten steel is avoided. Secondary oxidization of the molten steel in the wire feeding process is avoided, dust emission is reduced, and the environment is protected.

The invention discloses a molten steel thermal insulating agent and belongs to the field of thermal insulating agents. The molten steel thermal insulating agent comprises the following components of,by mass, 70-100 parts of carbonized rice husk ash, 1-10 parts of carbon source and 1-30 parts of silicon source, and the carbonized rice hull ash comprises the following elements of, by mass, 2%-17% of C, 40%-60% of Si, and the balance H, O, S, Ca, Fe and P. Water of the carbonized rice husk ash is less than 3% of the total mass of the thermal insulating agent. The bulk density of the molten steelthermal insulating agent is 0.18-0.35 g / cm<3>. Compared with carbonized rice hulls of a honeycomb structure, the molten steel thermal insulating agent provided by the invention can make the surface temperature of molten steel be lowered to 0.78 DEG C.min<-1> from 1.56 DEG C.min<-1> maximally. The molten steel thermal insulating agent provided by the invention is low in heat conductivity coefficient, good in thermal insulating effect, excellent in spreadability, free of caking, and low in production cost.

The invention provides a process for optimizing the grain size grade difference of a large-size nickel-based superalloy bar, and belongs to the technical field of nickel-based superalloy bar manufacturing. The process comprises the following steps that S1, raw materials are weighed and smelted to obtain an electroslag ingot; s2, uniform diffusion annealing is carried out; s3, heating before forging to obtain a forging stock; s4, the forging stock is subjected to two times of drawing-out and two times of upsetting treatment, and a semi-finished product is obtained; and S5, the semi-finished product is continuously drawn out, and the bar is obtained. Through the integral design of the whole process scheme such as component design, four-section type diffusion annealing and setting of the forging temperature and the environment temperature, the thermal deformation resistance during forging is greatly reduced, center grains are refined, the grain size grade difference from the edge to the core of the GH4169 bar is controlled within the 1.5 grade, and the process is feasible, low in cost and suitable for large-scale production. The problem that the grain size grade difference of the nickel-based superalloy bar with the diameter larger than or equal to 350 mm is large is solved for the first time.

The invention belongs to the technical field of moulds, and is specifically an intelligent constant-temperature injection mold, which includes a main body; multiple sets of isolation plates are arranged on the side wall of the main body; a thermal insulation resistance is fixedly connected to the side of the isolation plate away from the main body. Combustible material; the side close to the main body of the isolation plate is fixed with a cylinder; the gas inside the gas storage tank will cause the effect of heat expansion and contraction, and is introduced into the rodless cavity of the cylinder by the first air guide tube, and then the cylinder is It will push the isolation plate away from the main body, increase the space between the isolation plate and the main body, and accelerate the cooling speed of the main body. When the temperature of the main body is low, the gas inside the gas storage tank will shrink, and the cylinder will be inactive. The gas inside the rod cavity is drawn out, so that the insulation board and the heat preservation and flame retardant material are close to the body, so that the temperature drop speed of the body is slowed down, and the insulation effect of the insulation board and the heat preservation flame retardant material on the body is increased.

The invention aims to provide a quenched-tempered heat treatment method for bearing sleeve machining. The heat treatment method comprises the steps that (1) pre-heating treatment is carried out, specifically, a bearing sleeve used in the machining process is made from 20CrMnTi steel, the rough-machined bearing sleeve is preheated to 350 DEG C, and heat preservation is carried out for 30 minutes at a constant temperature; (2) normalizing heating is carried out on the bearing sleeve, specifically, the bearing sleeve which is pre-heated in the step 1 is further subjected to secondary heating to reach 800 DEG C; (3) quenching and cooling treatment is carried out, specifically, cold water is firstly sprayed on the surface of the high-temperature bearing sleeve to carry out cold water cooling, when the temperature of the bearing sleeve is decreased to 530 DEG C, water spraying is stopped, and then the bearing sleeve is immersed into oil for secondary cooling and then is placed in air to be air-cooled to 120 DEG C; and (4) high-temperature tempering treatment is carried out. The method has the advantages that the temperature reduction speed in the quenching process can be decreased, the temperature difference between inside and outside of the bearing sleeve can be reduced, the surface fracture in the quenching process can be avoided, the quenching quality can be improved, and the hardness and the surface wear resistance of the bearing sleeve can be improved.

The invention relates to a stove with a heat preservation function, and relates to the technical field of stoves. The stove with the heat preservation function comprises a first working position and asecond working position which are adjacently arranged, wherein the first working position is provided with a cooking stove used for cooking food, the second working position is provided with a heat preservation assembly, the heat preservation assembly comprises a heat preservation box body and a cover body, a containing cavity with an opening in one side is formed in the heat preservation box body, and the cover body is movably installed on the heat preservation box body and used for opening or closing the opening. The stove relieves the technical problem that by means of a stove in the priorart, the temperature of the cooked food cannot be effectively kept after cooking of the food is completed.

The invention discloses an environment-friendly cold chain circulation heat preservation carton, and relates to the technical field of heat preservation cartons, the environment-friendly cold chain circulation heat preservation carton comprises a cold chain box, a heat insulation and preservation layer and a phase change layer are arranged in the cold chain box, the heat insulation and preservation layer is located on the outer side of the phase change layer, the heat insulation and preservation layer is aerogel heat insulation felt, and the phase change layer is filled with fatty acid; according to the invention, the fatty acid phase-change material filled in the phase-change layer can sensitively sense the temperature change in the box and generate phase change in time, when the temperature rises, solid fatty acid is converted into liquid fatty acid, and a large amount of heat is absorbed to prevent the temperature from rising rapidly; and when the temperature drops, the liquid fatty acid turns back to the solid state to release heat, so that the temperature drop speed is slowed down, the temperature in the box is always maintained in an appropriate stable interval, the fresh-keeping time of the cold-chain transportation articles is greatly prolonged, and the quality and safety of the articles are not influenced by temperature fluctuation.

The invention discloses a natural gas sampling device and a method thereof, which belong to the field of gas sampling. The device comprises a tubular sampling probe, wherein a sampling port is inserted into a natural gas pipe at one end, and a safety bottle is connected with the other end; a heating assembly for heating the tubular sampling probe and the safety bottle; a sampling pump connected tothe safety bottle through a first pipeline; and a sampling air bag, wherein the sampling air bag is detachably connected to the sampling pump through a second pipeline, and the sampling air bag is provided with an intake valve and an outlet valve. The natural gas sampling device provided by the invention can avoid the clogging of the sampling port, and the obtained sample has the advantages of good quality and convenient usage, and is suitable for large-scale popularization and application.

The invention discloses a control method of an air conditioner, the air conditioner and a computer readable storage medium. An outdoor unit of the air conditioner comprises an outdoor heat exchanger,a first fan and a second fan, wherein an air outlet surface of the first fan is opposite to the upper part of an indoor heat exchanger, and an air outlet surface of the second fan is opposite to the lower part of the outdoor heat exchanger. The control method of the air conditioner comprises the steps that after the air conditioner enters a refrigeration mode and the outdoor temperature is less than a first preset temperature, the outlet temperature of the outdoor heat exchanger is obtained, and after the air conditioner enters the refrigeration mode, the first fan and the second fan are in anoperation state; and when the outlet temperature is less than a second preset temperature, the rotating speed of the target fan is reduced, wherein the target fan comprises at least one of the firstfan and the second fan. According to the control method and the air conditioner, the frequency of starting and stopping a compressor is low.

The invention relates to a combustion-heated heating ball, which is a hollow ball body compounded by a fireproof material layer and a combustible material layer, and a centripetal through hole is manufactured on the ball body. By adding the heating ball to the melt liquid metal surface of the high-temperature conveying equipment during the metallurgical production, the combustible material of the ball body is contacted with the oxygen above the melt liquid metal surface to carry out combustion reaction to emit heat under the radiation and heating action of the high-temperature liquid metal, so as to heat the liquid metal and the equipment; at the same time, the fireproof ball housing not only can serve as the carrier of solid fuel, but also can be used for thermal insulation, so as to reflect and block the combusting heat and the heat emitted by the liquid metal, as a result, the heating effect of the heating ball is improved, the thermal insulation function is achieved, the temperature drop speed of the liquid metal is reduced, and the purpose of energy saving is achieved. Due to the heat emitted by the heating ball, the temperature surrounding the openings of the liquid iron ladle and the steel ladle for containing the melt liquid metal in the steel industry is kept very high, as a result, the slag bonding problem on the brims of the liquid iron ladle and the steel ladle is greatly reduced.

The utility model discloses a composite molten aluminum ladle lining, and relates to the technical field of casting melt containers such as casting ladles, tundishes, pouring cups or the like. The composite molten aluminum ladle lining comprises a ladle shell, a ladle lining bottom is fixedly connected to the bottom wall of the ladle shell, a ladle lining wall is fixedly bonded to the inner wall of the ladle shell, the ladle lining wall is fixedly connected to the upper side of the ladle lining bottom, an aluminum outlet pipeline is fixedly connected to the left side of the outer surface of the ladle shell, and the outer surface of the ladle shell is fixedly sleeved with a second flange; the ladle cover is installed on the upper side of the second flange, eight second bolts are installed on the upper side of the ladle cover in a threaded mode, and the heat preservation mechanisms are arranged on the aluminum outlet pipeline and the ladle cover correspondingly, in this way, multiple heat preservation measures cooperate for heat preservation, and heat loss of molten aluminum in the molten aluminum two-man ladle can be effectively reduced; and the temperature reduction speed of the molten aluminum in the transportation and temporary storage process is reduced, and energy consumption needed by follow-up machining is reduced.

The utility model discloses an automotive crankcase ventilation pipe, which belongs to the technical field of crankcase ventilation pipes and is characterized by comprising a pipe joint, an outer pipe, an inner pipe, a connector and a connecting pipe, the pipe joint is connected with a connector of a crankcase, the outer pipe is detachably connected with the pipe joint through the connector, and the inner pipe is detachably connected with the pipe joint through the connecting pipe. The connecting pipe is communicated with a connector of the crankcase and the pipe joint, the inner pipe is arranged in the outer pipe, the inner pipe is communicated with an air outlet pipe of an air filter, and a clearance space is formed between the outer pipe and the inner pipe. Cold air or condensate water in the external environment is prevented from being in direct contact with the inner pipe, the clearance space between the outer pipe and the inner pipe can effectively reduce heat exchange between the inner pipe and the external environment, the temperature reduction speed in the inner pipe is slowed down, the inner pipe is prevented from being frozen to cause blockage, and smooth operation of the curved through box ventilation pipe in the low-temperature environment is ensured.

The invention discloses a quenching device after hot rolling forming of steel balls. The quenching device after hot rolling forming of the steel balls comprises a box body; the bottom of the inner wall of the box body is fixedly connected with a quenching box; a first fixing plate and a second fixing plate are sequentially and fixedly connected to one side between the opposite two sides of the inner wall of the box body from top to bottom; the top of the first fixing plate is rotationally connected with a spiral feeding roller through a pair of rotating bases; one side of the bottom of the inner wall of the box body is fixedly connected with a first motor; the output shaft end of the first motor is fixedly connected with a speed reducer through a coupler; a rotating device is fixedly connected with the top of the second fixing plate; one side of the rotating device is fixedly connected with a rotating plate through a rotating shaft; a moving device is fixedly connected with the top ofthe inner wall of the box body; and a heating pipe is fixedly connected with the bottom of the moving device. The invention relates to the technical field of steel ball machining. The quenching deviceafter hot rolling forming of the steel balls solves the problem that the steel balls are affected by temperature in the transferring process, meanwhile solves the problem of manual flow distributing,reduces the labor amount and improves the production efficiency.

The invention belongs to the technical field of molds, and particularly relates to an intelligent constant-temperature injection mold which comprises a body. A plurality of groups of isolation plates are arranged on the side wall of the body. The side, away from the body, of each isolation plate is fixedly connected with a heat preservation flame-retardant material. An air cylinder is fixedly connected to the side, close to the body, of each isolation plate. Gas in gas storage tanks can cause the effect of heat expansion and cold shrinkage and is guided into rodless cavities of the ai cylinders through first gas guide pipes, then the air cylinders push the isolation plates away from the body, the space between the isolation plates and the body is increased, the cooling speed of the body can be increased, and when the temperature of the body is low, the gas in the gas storage tanks is shrunk, the gas in the rodless cavities of the air cylinders is pumped out, so that the isolation plates and the heat-preservation flame-retardant material are close to the body, the temperature reduction speed of the body is reduced, and the heat-preservation effect of the isolation plates and the heat-preservation flame-retardant material on the body is improved.

The invention relates to a milk supplementing device for suckling pigs. The milk supplementing device comprises a trough, a trough cover box, nipples, separation rods and a lifting frame. The milk supplementing device is simple in structure, reasonable in design and detachable. When the trough cover box and the nipples are not assembled, the milk supplementing device can be used as a crib of granular fodder and dry powdered fodder. Accordingly, the milk supplementing device is multifunctional and suitable for pig farms of different sizes and pigs of different days, and the utilization of the device is improved. Under the condition that new-born suckling pigs are short of milk or sows can not provide enough milk, the milk supplementing device can supplement milk for several suckling pigs, therefore, the survival rate and the growing speed of the suckling pigs can be improved, labor intensity of workers is lowered, and economic benefits of the pig farms are improved.

The invention discloses a control method of an air conditioner. The outdoor unit of the air conditioner includes an outdoor heat exchanger, a first fan and a second fan. The air outlet surface of the first fan is opposite to the indoor heat exchanger. The air outlet surface of the second fan is arranged on the lower part of the outdoor heat exchanger. The control method of the air conditioner includes the following steps: after the air conditioner enters the cooling mode, and the outdoor temperature is lower than the first preset temperature, the outlet temperature of the outdoor heat exchanger is obtained. After the air conditioner enters the cooling mode, the first fan and the second fan are in the running state; when the outlet temperature is lower than the second preset temperature, lower The rotational speed of a target fan, where the target fan includes at least one of the first fan and the second fan. The invention also discloses an air conditioner and a computer-readable storage medium. The frequency of starting and stopping of the compressor of the present invention is relatively low.

The invention discloses a water multi-unit system control method, device, a computer readable storage medium and a water multi-unit system. The method comprises steps: whether a room where the water multi-unit system is located has a cooling load requirement or not is determined; if the room where the water multi-unit system is located has the cooling load requirement, whether the set cold accumulation capacity of a cold accumulation tank reaches a set cold capacity threshold value or not is determined; and if the cold accumulation capacity in the cold accumulation tank does not reach the setcold capacity threshold value, the water multi-unit system is controlled to start a cold accumulation mode and a refrigeration mode at the same time, and the output cold accumulation capacity of the cold accumulation tank is controlled according to the current starting number of indoor units in the multi-unit system. According to the scheme, the problem that the comfort of a user is poor due to the fact that the indoor unit and the outdoor unit of the water multi-unit machine cannot be linked can be solved, and the effect of improving the comfort of the user is achieved.

The invention discloses a molten steel thermal insulating agent and belongs to the field of thermal insulating agents. The molten steel thermal insulating agent comprises the following components of,by mass, 70-100 parts of carbonized rice husk ash, 1-10 parts of carbon source and 1-30 parts of silicon source, and the carbonized rice hull ash comprises the following elements of, by mass, 2%-17% of C, 40%-60% of Si, and the balance H, O, S, Ca, Fe and P. Water of the carbonized rice husk ash is less than 3% of the total mass of the thermal insulating agent. The bulk density of the molten steelthermal insulating agent is 0.18-0.35 g / cm<3>. Compared with carbonized rice hulls of a honeycomb structure, the molten steel thermal insulating agent provided by the invention can make the surface temperature of molten steel be lowered to 0.78 DEG C.min<-1> from 1.56 DEG C.min<-1> maximally. The molten steel thermal insulating agent provided by the invention is low in heat conductivity coefficient, good in thermal insulating effect, excellent in spreadability, free of caking, and low in production cost.

A sampling device for bar rolling intermediate process quality control comprises a supporting bottom plate, a front wheel assembly is installed in the middle of the lower portion of the supporting bottom plate and is a universal wheel, and rear wheel assemblies are installed on the two sides of one end of the supporting bottom plate and are directional wheel sets; a handrail frame is mounted on the supporting bottom plate on the side of the directional wheel; a sampling box is arranged on the supporting bottom plate on the opposite side of the handheld frame, the downward projection plane of the sampling box is kept away from the front wheel assembly, and a gravel buffer layer is laid in the sampling box; and a balancing weight is arranged on the supporting bottom plate on the side of the hand-held frame. In actual production, the steel heads sheared by the first shear can be safely and conveniently collected, the problems that the temperature of the steel heads is rapidly reduced, continuous rolling production is affected, and the operation rate is reduced are effectively solved, sample surface gouges are effectively prevented, and production continuity and safety are improved.

The invention provides a nano phase-change constant-temperature culture dish which is characterized in that a single-layer structure of a traditional culture dish is improved, a double-layer culture dish in a hollow sandwich structure form is manufactured, a nano phase-change constant-temperature capsule material is injected into the middle of a sandwich layer, and the nano phase-change constant-temperature culture dish is manufactured after the sandwich layer is sealed. According to the culture dish, when the environment temperature rises, the nano phase-change capsule material can absorb andstore external heat, and when the environment temperature is lower than the phase-change temperature, the nano phase-change capsule material can release heat outwards, so that the temperature in theculture dish is kept relatively stable within a certain time range. The invention also provides a manufacturing method of the nano phase-change constant-temperature culture dish.

The embodiment of the invention provides a refrigerator capable of preventing the upper surface of a middle beam from being frozen, and relates to the technical field of refrigeration equipment. The refrigerator is provided for solving the problem that a lead of a heating device of a middle beam of an existing refrigerator is likely to be affected with cold and damp so as to be aged. The refrigerator capable of preventing the upper surface of the middle beam from being frozen comprises a box body and door bodies used for sealing the box body. The middle beam is arranged at the position of an opening of the box body. The middle beam is of a hollow structure, a heating device is arranged inside the middle beam, and the middle beam is filled with heat insulation materials. The end of the middle beam is in sealed connection with the inner wall of the box body. A lead of the heating device is electrically connected with a control circuit of the refrigerator after penetrating out of the end of the middle beam and the inner wall of the box body. The refrigerator capable of preventing the upper surface of the middle beam from being frozen is used for storing goods at a low temperature.