10 results about "UREA POWDER" patented technology

The utility model provides a high-speed negative pressure spraying device for a denitration skid-mounted station, which relates to the technical field of spraying devices and comprises a volute fan, and the output end of the volute fan is connected with a spraying assembly. The spraying assembly comprises a conical air spraying pipe connected with the output end of the volute fan, and the conical air spraying pipe is sleeved with a spraying pipe; the injection pipe sequentially comprises a negative pressure cavity, a folding cavity, a smooth cavity, a release cavity and a flow guide cavity from left to right. According to the utility model, negative pressure can be formed when high-speed air flow passes through the negative pressure cavity, urea powder is sucked into the negative pressure cavity to be mixed with air, and the urea powder is efficiently conveyed to a reaction area through the high-speed air flow to be fully contacted and reacted with NOx, so that the urea is decomposed into ammonia gas, and the denitration efficiency is improved; a urea solution is replaced, and the problems that a traditional liquid reducing agent injection system is uneven in injection, high in equipment complexity and poor in environmental adaptability and has leakage hidden dangers are solved.

The invention provides a method for preparing coal-based quantum carbon dot slow-release urea through sectional drying-fluidized bed granulation, and relates to the technical field of slow-release fertilizer preparation, the method comprises the following steps: S1, coal-based waste is used as a raw material, coal-based quantum carbon dots MCQDs are prepared through a hydrothermal method, a silane coupling agent is added for surface functional modification, and a functional MCQDs dispersion liquid is obtained; s2, industrial urea is smashed and screened, and urea master batches with the particle size ranging from 1.0 mm to 3.0 mm are obtained; in the pre-drying stage, moisture on the surfaces of urea master batches is thoroughly removed through a low-humidity environment, and particle aggregation caused by moisture during MCQDs spraying is avoided; in the medium-temperature setting stage, in an interval lower than the urea decomposition temperature, MCQDs are promoted to form a covalent bond with a urea crystal face through a silane coupling agent, and the bonding stability is improved; the formed bonding structure is locked in the low-temperature curing stage, structural damage caused by temperature fluctuation is avoided, and the problem of decomposition or agglomeration is solved.

This invention relates to the field of urea granulation tail gas purification technology, and particularly to a method for purifying dust and ammonia in the tail gas of large-particle urea granulation. The method includes: passing the tail gas containing urea dust and ammonia through a baffle tower with a dust-washing side and an ammonia-absorbing side; removing urea dust from the tail gas through a dust removal process on the dust-washing side to obtain dust-washed tail gas; introducing the dust-washed tail gas through gas channel holes on the baffle into the ammonia-absorbing side, removing ammonia from the tail gas through an ammonia absorption process to obtain purified tail gas; wherein the dust-washing side and the ammonia-absorbing side are independent of each other, allowing only the dust-washed tail gas to circulate. The ammonium sulfate mother liquor collected from the ammonia-absorbing side is introduced to the dust-washing side through a pipeline and mixed with the mother liquor from the dust-washing side; the remaining mother liquor is recycled after adding acid; a portion of the ammonium sulfate-containing urea mother liquor from the dust-washing side is discharged to the next stage, and the remaining mother liquor continues to be recycled. This invention enables a single device to simultaneously meet the dual emission requirements of dust and ammonia in urea granulation tail gas treatment.

The invention relates to the technical field of urea prilling towers, and particularly provides a urea prilling tower top ammonia removal and dust fall recovery device which comprises a carbon dioxide storage tank, a Venturi ejector, a spray pipe, a stainless steel wire net, a filter cloth bag, an induced draft fan, a back flushing pipeline and a factory air buffer tank. Carbon dioxide gas in a carbon dioxide storage tank enters a venturi ejector, process condensate enters the venturi ejector to form a gas-liquid mixture with carbon dioxide, the gas-liquid mixture enters a spraying pipe to be sprayed out, and a water mist film containing the carbon dioxide gas is formed on a stainless steel wire net; and the water mist film is in contact reaction with air containing free ammonia and urea dust from the prilling tower on the stainless steel wire mesh, so that the effects of fixing ammonia and reducing dust are achieved. The induced draft fan above the filter cloth bag has the suction effect, and the gas is filtered by the filter cloth bag, so that the effect of further reducing dust is achieved. The back flushing pipeline is used for washing and back flushing and drying the filter cloth bag, and the effect that the filter cloth bag can be repeatedly used for dust falling is achieved.

The utility model relates to the technical field of urea dust treatment, in particular to wet-process urea dust recovery equipment. In order to solve the problem that existing cloth bag filtering type urea dust recycling equipment has many defects, the novel wet-process urea dust recycling equipment is provided and comprises a dust remover, a dust removal fan, an emptying barrel, a washing circulating tank and a circulating pump, the dust remover comprises a dust removal bin, and a liquid blocking silk screen layer, a spraying layer and a filler layer are sequentially arranged in the dust removal bin from top to bottom. A dust removal discharging port of the dust removal bin is connected with a feeding port of the washing circulating tank, the washing circulating tank is provided with a liquid outlet and a liquid supplementing port, the liquid outlet is communicated with an inlet of the circulating pump, an outlet of the circulating pump is communicated with the multiple nozzles through a circulating pipeline, and the outlet of the circulating pump is further communicated with the granulation dissolving tank through a granulation dissolving pipeline. A dissolving valve is arranged on the granulation dissolving pipeline, the liquid supplementing port is connected with a liquid supplementing pipeline, and a liquid supplementing valve is arranged on the liquid supplementing pipeline. The equipment effectively saves the production cost.

The application provides a urea dust circulation recovery system and method, the urea dust circulation recovery system comprises a dust collecting device, a spraying device is arranged above the dust collecting device, a solution storage device is connected to the bottom of the dust collecting device, the solution storage device is connected to the spraying device through a reflux pipeline, so that urea circulates and flows among the spraying device, the dust collecting device and the solution storage device, and a liquid discharge pipeline is led out on the reflux pipeline. The urea dust circulation recovery system provided by the application not only realizes recycling and reuse of urea solution, but also saves water resources, improves urea yield, reduces production cost, can automatically control the circulation amount and concentration of urea solution according to actual needs, has high automation degree and saves operation and maintenance cost.

The invention belongs to the field of urea hot-melt recovery, and particularly relates to a dust urea online hot-melt recovery process which comprises the following steps: dust collection: collecting dust screened by a rotary screen into a urea dust hot-melt recovery device through a shuttle pipe; and adding hot melting water: adding 90-100 DEG C steam condensate, desorption waste liquid or 140-145 DEG C liquid discharged from the second desorption tower into the middle lower part of the hot melting tank. The hot melting recovery device is used for carrying out centralized treatment on dust urea in the production process, and a dust packaging link is not needed, so that the problem that dust escapes in the packaging process is avoided from the source, and the production efficiency is improved. And the working environment of a packaging station is effectively improved, and the influence of dust on the health of operators is reduced. The urea which is originally treated as low-value dust is fully recycled and granulated again through links such as hot melting, stirring and circulating dissolving, so that the dust urea is converted into a qualified granular urea product, byproducts generated in the production process are utilized to the maximum extent, and resource waste is reduced.

The utility model provides a dust falling device for chemical production safety engineering, which relates to the technical field of dust falling devices and comprises a bottom plate, a conveying device body is arranged at the top of the bottom plate, a dust falling component is arranged at the top of the bottom plate close to the center, and the dust falling component comprises two fixing frames. A lower communication bin is fixed between the outer surfaces of the two fixing frames. According to the device, when urea needs to be crushed, firstly, large-particle urea is crushed through the crusher body, the crushed urea is conveyed to the top of the conveying device body, then small-particle dust on the surface of the urea can be completely absorbed and collected in a negative pressure mode, and after the dust on the surface of the urea is cleared away, the urea is conveyed to the top of the conveying device body. The problems that in the prior art, the dust removal effect of dust removal equipment used after the urea is smashed is low, and the practicability of the dust removal device for the chemical production safety engineering is reduced are solved.

This invention relates to the field of photocatalysis technology, specifically to a method for degrading nitrogen oxides using solution plasma-modified graphitic carbon nitride. This method addresses the problems of existing traditional bulk g-C3N4 structures used for photocatalytic removal of low-concentration NO, such as rapid recombination rates of photogenerated electron-hole pairs, low charge separation efficiency, limited quantum yield, weak adsorption capacity for low-concentration NO, poor controllability of the reaction pathway, and easy generation of more toxic NO2 byproducts. The method includes the following steps: S1: Placing commercial urea powder in an alumina crucible and placing the crucible in a programmed temperature-controlled muffle furnace for high-temperature reaction. After the reaction, the reactants in the muffle furnace are ground and pulverized using a mortar and pestle. This invention utilizes light irradiating the catalyst material surface through the reactor to achieve photocatalytic degradation of low-concentration NOx pollutants in the environment. Under mild conditions, it enhances the catalyst's adsorption capacity and deep catalytic oxidation performance for nitrogen oxides, effectively improving the photocatalytic NOx removal efficiency.