46results about How to "Control temperature distribution" patented technology

Provided is a method for preparing methyl acetate by dimethyl ether carbonylation, comprising passing a feed gas including dimethyl ether, carbon monoxide and optional hydrogen through a reactor filled with a mordenite and / or ferrierite molecular sieve based catalyst and reacting at a reaction temperature of 190-320°C, a reaction pressure of 0.5-20.0 MPa and a gas space velocity of 500-5000 h-1 so as to prepare methyl acetate, wherein the molar ratio of dimethyl ether to carbon monoxide is DME / CO=1 / 1-1 / 15, the molar ratio of hydrogen to carbon monoxide is H2 / CO=0-10 / 1, and the feed gas is distributed into each catalyst bed layer in a segmental feeding manner. A feed gas including dimethyl ether and carbon monoxide is uniformly distributed into each catalyst bed layer via a gas distributor, in a segmental feeding manner, which can remarkably improve the conversion rate of dimethyl ether, effectively control or adjust the temperature distribution of a catalyst bed layer, avoid the appearance of a hot spot, and prolong the service life of a catalyst.

A shear-assisted solid state welding method for joining of metal parts, involves a first step of heating opposing surfaces in a non-passivating environment to a temperature in the hot working temperature range of the metal. A second step involves bringing the opposing surfaces into contact while still in the hot working temperature range, and applying compressive stress sufficient to substantially prevent sliding in response to shear displacement, causing plastic flow in the hot layers. A third step involves imposing relative shear displacement of the metal work pieces without disengaging the opposing surfaces. The shear displacement induces plastic shear strain within the hot layers to progressively induce bonding.

The invention belongs to the related technical field of additive manufacturing, and discloses a temperature control device and method of a substrate for additive manufacturing. The device comprises a temperature control board, a temperature detection system and a temperature control system. The temperature control board is arranged below the substrate and comprises a plurality of subareas, and each subarea is internally provided with a hollow metal spiral coil. The temperature monitoring system comprises an infrared thermal imager, a thermocouple and multiple channels of thermodetectors. The temperature control system comprises a control cabinet, a water cooling machine, an alternating current power supply and a subarea channel valve. The control cabinet performs electromagnetic heating or cooling water cooling on the substrate subareas based on a heat transfer rule and a temperature monitoring result. According to the invention, timely and accurate temperature regulation and control of different areas of the substrate for additive manufacturing can be achieved, so that temperature distribution of the substrate is regulated and controlled, stress and deformation of the substrate are controlled, and cracking and large deformation of the substrate in the additive manufacturing process are prevented.

Provided is a method for preparing methyl acetate by dimethyl ether carbonylation, comprising passing a feed gas including dimethyl ether, carbon monoxide and optional hydrogen through a reactor filled with a mordenite and / or ferrierite molecular sieve based catalyst and reacting at a reaction temperature of 190-320°C, a reaction pressure of 0.5-20.0 MPa and a gas space velocity of 500-5000 h-1 so as to prepare methyl acetate, wherein the molar ratio of dimethyl ether to carbon monoxide is DME / CO=1 / 1-1 / 15, the molar ratio of hydrogen to carbon monoxide is H2 / CO=0-10 / 1, and the feed gas is distributed into each catalyst bed layer in a segmental feeding manner. A feed gas including dimethyl ether and carbon monoxide is uniformly distributed into each catalyst bed layer via a gas distributor, in a segmental feeding manner, which can remarkably improve the conversion rate of dimethyl ether, effectively control or adjust the temperature distribution of a catalyst bed layer, avoid the appearance of a hot spot, and prolong the service life of a catalyst.

Provided in the present invention is a process for preparing methyl acetate through carbonylation of dimethyl ether, comprising: passing a feed gas containing dimethyl ether, carbon monoxide, and optional hydrogen gas through a reactor loaded with a mordenite molecular sieve catalyst, and preparing methyl acetate by reacting same at a reaction temperature of 19 to 320°C, a reaction pressure of 0.5 to 20.0 Mpa, and a gas volume space velocity of 500 to 5000 h-1; wherein the mordenite molecular sieve catalyst is a hydrogen-type mordenite molecular sieve catalyst with an adsorbed organic amine, the molar ratio of the dimethyl ether to carbon monoxide in the feed gas is DME / CO = 1 / 1 to 1 / 15, the molar ratio of the hydrogen gas to carbon monoxide is H2 / CO = 0 to 10 / 1, and the dimethyl ether in the feed gas is charged into the reactor by means of feeding in stages. The present invention is characterized in that: through treatment by organic amine adsorption, the temperature distribution of catalyst bed can be effectively controlled so as to avoid the occurrence of hot points, and thereby side reactions are reduced, the selectivity of target product is improved, and the lifetime of the catalyst is greatly extended.

The invention relates to a casting method of large-scale high pressure resisting multi-cylinder-block cast. The method includes the following steps: (1) mold making, (2) sand mold making, and (3) casting molding: during the sand mold making of the step (2), a sprue is designed into a first sprue (1) and a second sprue (3), a cross gate is designed into a first cross gate (2) and a second cross gate (4), and an ingate (5) is designed into a plurality of parallel pouring gates. Cross section area of all pouring gates is set as the following relation: the cross section area of the first sprue (1) is larger than that of the first cross gate (2), the cross section area of the first cross gate (2) is smaller than that of the second sprue (3), the cross section area of the second sprue (3) is larger than that of the second cross gate (4), and the cross section area of the second cross gate (4) is smaller than that of the ingate (5). The casting method overcomes the defects that shrinkage cavities, shrinkage porosities, slag inclusion and the like do not exist in the cast and can meet quality requirements that cylinder holes can be used as cylinder inner walls after the cylinder holes are machined.

The invention discloses a process for producing resorcinol by continuously hydrolyzing m-phenylenediamine. The devices adopted by the process include a pipe mixer, a heat exchanger and a tower reactor, wherein baffle plates are distributed in the tower reactor from top down and the external wall of the tower reactor is provided with a heating pipe coil. The process comprises the following steps: 1, continuously preparing a hydrolysis raw material by using the pipe mixer to form homogeneous aqueous solution of m-phenylenediamine sulfate; 2, preheating the aqueous solution of m-phenylenediaminesulfate to 225 to 245 DEG C by the heat exchanger, continuously filling the aqueous solution of m-phenylenediamine sulfate to the tower reactor from the top part of the tower reactor, keeping the reaction and retention time of the reaction material in the tower reactor between 120 and 240 minutes, and performing continuous hydrolysis reaction; and 3, performing post-processing step of the hydrolysis reaction solution obtained by the hydrolysis reaction to obtain the resorcinol. The process has the characteristics of high equipment efficiency, short production period, high product yield, stable product quality and simple and convenient process control.

The production method of high α-phase silicon nitride powder includes the following steps: A: grinding and pulverizing silicon powder to a D90 of 6 μm; B: loading the ground silicon powder into a sagger, and the thickness of the charging is within 15-30mm time; C: stack multiple saggars filled with silicon powder up and down into a stack, and the total thickness of silicon powder in each saggar in the stacked stack is less than or equal to 300mm; D: stack multiple stacks of silicon powder Put the saggars into the vacuum heating furnace, the total weight of the silicon powder in the multiple stacks of saggars filled with silicon powder is 70-100kg, and the multiple stacks of saggars filled with silicon powder are in an array form; Pumped to below 100Pa; F: filled with nitrogen to 60kPa; G: heating reaction. By adopting the method for large-scale production of silicon nitride, a high content of α phase can be obtained.

The invention belongs to the technical field of heat recycling and energy conservation and relates to a controllable waste heat recycling device for a cooling window of an electrolytic aluminum bath. The controllable waste heat recycling device comprises a circulating water pump adjustment control wire, a supplementary water pressure pump, an ejector, a circulating water pump, a master liquid supply pipe, liquid distribution branch pipes, a first branch flow adjusting valve, first heat extraction units, second heat extraction units, nth heat extraction units, two-phase flow branch pipes, a circulating water pipe, a pressure pump adjustment control wire, a liquid distributor, a second branch flow adjusting valve, a master two-phase flow pipe, a gas-liquid separator, a liquid level meter, a water level signal line, a central controller, a safety valve, a steam temperature and pressure signal line, a heat extraction unit temperature signal line, a gas supply pipe, an mth branch flow adjusting valve, heat extraction branches, water inlet pipes, water outlet pipes, other heat extraction units and a lower steel plate. By means of the controllable waste heat recycling device, waste heat of the cooling window is utilized reasonably, the work environment of a workshop is improved, temperature distribution in the electrolytic aluminum bath is effectively controlled, the production cost is reduced, the overall structural design is simple, principles are scientific, and the application environment is friendly.

The invention provides an air conditioner power supply control system based on multipoint temperature sensing. The air conditioner power supply control system comprises refrigeration control units arranged in different space positions; the refrigeration control units include temperature sensors, control relays, refrigeration exhaust ports, control chips and communication modules; the control relays are used for controlling the power supply on and off of the refrigeration exhaust ports; the communication modules are connected with a remote control terminal; all the temperature sensors obtain the temperature data and send to the control chips; and all the control chips send the temperature data to the remote control terminal. The air conditioner power supply control system based on multipoint temperature sensing can control the temperature distribution in whole space through multipoint temperature detection, and guarantees the lowest refrigeration consumption.