Urea formaldehyde drying method

Abstract

The invention relates to the technical field of urea formaldehyde processing, in particular to a urea formaldehyde drying method. The urea formaldehyde drying method comprises the steps that produced urea formaldehyde is spread in a movable dryer and pre-dried in the movable dryer; a wet layer and a dry layer of the pre-dried urea formaldehyde are separated, and the pre-dried urea formaldehyde is dried again through a cyclone dryer, so that finished urea formaldehyde is obtained. By the adoption of the urea formaldehyde drying method, the phenomenon that the urea formaldehyde with the high moisture content is caked due to the fact that cyclone drying treatment is conducted on the urea formaldehyde with the high moisture content is avoided, and the dispersity and activity of the dried urea formaldehyde are high.

Description

technical field [0001] The invention relates to the technical field of urea-formaldehyde processing, in particular to a method for drying urea-formaldehyde. Background technique [0002] In the prior art, for the production of urea-formaldehyde, formaldehyde and urea are mixed in the solution, the temperature, pH value and reaction time of the reaction process are controlled, and after polymerization to form a urea-formaldehyde mixture, it is placed in a dry place. Dry the obtained urea-formaldehyde dry product in the container. [0003] The demand for urea-formaldehyde in the market is relatively wide, but it is mainly used in the fields of compound fertilizer, nitrogen fertilizer or as an additive, and in these fields, urea-formaldehyde is required to have high activity and high dispersibility, and according to relevant research The research of the author shows that urea-formaldehyde is prepared by the mixed reaction of formaldehyde and urea, without drying treatment step...

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Problems solved by technology

[0003] The demand for urea-formaldehyde in the market is relatively wide, but it is mainly used in the fields of compound fertilizer, nitrogen fertilizer or as an additive, and in these fields, urea-formaldehyde is required to have high activity and high dispersibility, and according to relevant research The research of the author shows that urea-formaldehyde is prepared by the mixed reaction of formaldehyde and urea, without drying treatment step, its own activity and dispersibility are good, but after drying treatment, it will affect the activity of urea-formaldehyde and dispersibility, so that the quality of urea-formaldehyde is low; The reason for reducing its activity and dispersibility during the drying process is that urea-formaldehyde itself has strong adhesiveness, while traditional drying uses microwave drying, cyclone drying, stirring and heating drying, etc.; When dealing with urea-formaldehyde, due to insufficient temperature caused by microwave radiation treatment or short-term microwave drying treatment, the urea-formaldehyde is not completely dried, resulting in easy agglomeration and hardening of urea-formaldehyde, resulting in lower quality of urea-formaldehyde; if the microwave radiation is long Time or high-frequency treatment will quickly dry the moisture on the surface of urea-formaldehyde, but it is difficult to quickly dry the moisture inside the urea-formaldehyde crystal, which will cause unevenness inside and outside; resulting in longer drying time and higher cost; And with the properties of urea-formaldehyde itself, its properties will be destroyed during the long-term microwave radiation drying process, which will affect the dispersibility and activity of urea-formaldehyde; The moisture content of urea-formaldehyde is relatively large, and then when carrying out cyclone drying in the cyclone drier, agglomerates are easily formed, thereby affecting the quality of urea-formaldehyde, reducing the dispersibility and activity of urea-formaldehyde; when adopting stirring and drying, it is more It is easy to make urea-formaldehyde form lumps or lumps, which will affect its dispersibility

[0004] In summary, it is difficult to avoid stirring urea-formaldehyde under high moisture content in the drying treatment methods of urea-formaldehyde in the prior art, which makes urea-formaldehyde agglomerate or agglomerate during the drying process, which affects the urea-formaldehyde Activity and dispersibility defects

Moreover, most of the urea-formaldehyde production in the prior art is to react urea and formaldehyde, and then use it as a raw material to produce compound fertilizers or other products, so there is no single solution for drying urea-formaldehyde to prepare products, resulting in ready-made urea-formaldehyde The storage capacity of formaldehyde products is small, and it is difficult to meet the large demand for urea-formaldehyde in the market

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