The disclosure discloses a spiral-flow type fluidized-bed cooling crystallization system. The system comprises a first fluidized-bed crystallizer, a second fluidized-bed crystallizer, a crystal growing tank, a centrifuge, a circulating pump, a flow control valve, a densimeter and the like, wherein vertical heat transfer pipes are arranged in the first fluidized-bed crystallizer and the second fluidized-bed crystallizer, and scraping particles are contained in the heat transfer pipes. According to the invention, feed liquid exchanges heat with a cooling medium through the vertical heat transfer pipes; meanwhile, spiral spray heads at the bottoms of the heat transfer pipes are used for enabling the feed liquid in the pipes to form a spiral flow field, and the scraping particles are efficiently driven to continuously impact and crush crystals attached to heat transfer wall faces, so the effects of heat transfer enhancement, heat transfer wall face self-cleaning.

Disclosed is a system for producing magnesium hydroxide including: a generation unit; and a recovery unit connected to the generation unit, wherein the generation unit has a reaction tank in which a calcium hydroxide slurry is added to water to be treated containing magnesium ions to crystallize magnesium hydroxide and to obtain a reaction slurry containing particles of magnesium hydroxide, and a sedimentation tank in which the reaction slurry is reserved to sediment the particles and to separate the reaction slurry into a separation slurry containing the particles at a high concentration and a separation liquid containing the particles at a low concentration, and wherein, in the recovery unit, an alkaline aqueous solution is added to the separation liquid to crystallize magnesium hydroxide and to obtain the reaction slurry and then the reaction slurry is reserved to sediment the particles and to recover the sedimented particles.

A method of operating a crystallizing vessel assembly, said vessel assembly having a crystallizing vessel, and a rotor comprising a rotor shaft, said rotor including a plurality of rotor arms, said rotor arms having arms attached to the rotor shaft and scrapers attached at the arms. The crystals are grown on the inside of the vessel and the rotor is rotated to scrape said crystals off. To improve liquid flow inside the crystallizing vessel, a plurality of arms of the rotor arms are hollow arms, each arm of the plurality of arms including an inlet opening that is relatively close to the shaft and an outlet opening that is relatively far from the shaft.

The present disclosure generally relates to methods for deoiling a hydrocarbon feed and to products formed therefrom. In an embodiment is provided a method of deoiling a feed that includes introducing a waxy feed and a deoiling solvent to a dilution chilling zone; mixing the waxy feed and the deoiling solvent in the dilution chilling zone at a temperature of from about 10° F. to about 30° F. to form a slurry; introducing the slurry to a filter zone, the filter zone comprising one or more filter stages, wherein a temperature of the slurry is from about 40° F. to about 75° F.; separating the wax from the oil and the deoiling solvent to form a wax cake in a first filter stage; and washing the wax cake in the first filter stage with the deoiling solvent to obtain a composition comprising a wax. In another embodiment is provided a composition comprising a wax.

A method for crystallization of β-ammonium tetramolybdate includes: performing a stepwise pH-adjusting treatment of an ammonium molybdate solution via zoning to obtain the β-ammonium tetramolybdate. When feeding the ammonium molybdate solution into a reaction system from a first zone and then into second to sixth zones successively, pH.sup.1 of a resultant solution in the first zone is 7.0-6.0; pH.sup.2 of a resultant solution in the second zone is less than 6 and greater than or equal to 4; pH.sup.3 of a resultant solution in the third zone is less than 4 and greater than or equal to 2.5; pH.sup.4 of a crystallized slurry in the fourth zone is less than 2.5 and greater than or equal to 1; pH.sup.5 of a crystallized slurry in the fifth zone is 2.5-4.0; and pH.sup.6 of a crystallized slurry in the sixth zone is less than 2.5 and greater than or equal to 2.0.

A method of isomerizing Δ9-tetrahydrocannabinol (“Δ9-THC”) to Δ10-tetrahydrocannabinol (“Δ10-THC”). The method includes the steps of: extracting Δ9-THC from cannabis biomass, which optionally contains one or more of the components found in fire retardant such as PHOS-CHEK®; dewaxing of crude extracts by winterization; pH-adjusting extracts by washing the extracts in heptane solution with aqueous solutions of: citric acid, sodium bicarbonate, and brine; isomerizing Δ9-THC to Δ10-THC by exposure to suitable conditions and in the presence of a catalyst based on the components of fire retardant; vacuum distillation of Δ10-THC at a predetermined temperature range and vacuum level; collecting the distillate and redistilling it up to three times to acquire distillate containing less than 60% Δ10-THC; and purification of the MO-THC to a purity of 99% or greater by crystallization from n-pentane solution.

A process for synthesis of urea from CO.sub.2 and NH.sub.3 wherein a steam flow (13) produced in the condenser (3) of a high-pressure synthesis loop is compressed to raise its pressure and temperature before using the steam as a heat source for a downstream step of the process.

A device for purifying a product by crystallization includes: a feed unit having a solution in which the total product concentration is substantially completely dissolved or a suspension with the total product concentration; a crystallization unit in which the product crystallizes and forms a solids content; a separation unit in which the crystallized product is separated from the solution or suspension; a temperature control unit for controlling temperature at least in the feed unit and/or the crystallization unit; and a control and evaluation unit that determines the total product concentration and/or the concentration of the solids content and/or the concentration of the dissolved product content and/or the concentration of an impurity content, taking into account the measured values of connected temperature sensors and of connected impedance sensors.

Disclosed is an external circulating slurry reactive crystallizer, including a riser, a degassing zone and a downcomer. A lower end of the riser is communicated with a gas inlet pipe, a liquid inlet pipe and a solid feeding pipe, while an upper end of the riser is communicated with a lower end of the degassing zone. An upper end of the downcomer is integrally fixed to a sidewall of the degassing zone. At least one hydrocyclone is arranged at a lower end of the downcomer. The hydrocyclone is provided with an overflow port at an upper end thereof and an underflow port and a valve at a lower end thereof. The overflow port is communicated with the riser. The crystallizer can simultaneously realize reaction, crystallization and separation for continuous production with low cost, regulating and controlling the particle size distribution and morphology of crystals.

The present invention discloses a saline glycerine wastewater treatment system and technology. The whole technological process mainly includes a reaction process, an evaporation process, a crystallization process, a filtration process and a drying process. The present invention first proposes the use of an “ammonia-alkali reaction principle” to treat high-salt glycerine wastewater, which mainly solves the problem of treating a large amount of calcium chloride-containing glycerine wastewater produced in the production process of propylene oxide and epichlorohydrin in chlor-alkali industry, and places emphasis on solving the problems that low value-added calcium chloride produced in the wastewater treatment process of a traditional method has low quality, is basically accumulated as solid waste and is difficult to treat, and chloride ions have adverse effects on the biochemical process of wastewater treatment. By-products of high-quality calcium carbonate and ammonium chloride products have high economic benefits and social environmental protection benefits.