离子交换树脂流化床干燥工艺的研究与改进

对离子交换树脂的两种流化床干燥工艺作了简单介绍,重点介绍了一种利用流化床连续干燥系统对离子交换树脂进行干燥冷却的工艺。此工艺针对离子交换树脂的特点进行设计。试验证明该工艺具有投资少和节能高效的特点,有很好的推广前景。     

氯化铵回转干燥工艺能耗和尾气排放分析

介绍了氯化铵的回转干燥工艺.从工艺、能耗、环保、非满负荷工况等方面对内加热流化床工艺和回转干燥工艺进行了对比分析.研究证明,回转干燥工艺的汽耗、电耗、尾气排放量均大幅度低于内加热流化床工艺.在非满负荷工况时,效果更加显著.     

热敏性物料干燥实验研究

根据聚碳酸酯产品的热敏性要求,对干燥工艺进行了分析研究,设计流化床干燥系统。实际应用表明,流化床系统具有产品质量符合要求、干燥效果好、操作使用方便等优点。     

微粉流化床干燥技术在脲醛缓释肥生产中的应用

将微粉流化床干燥技术用于脲醛缓释肥生产,介绍了微粉流化床干燥系统的工艺流程及主要设备工作原理,对各工艺参数进行优化,并详细论证了关键工艺参数的设计依据,选择出最佳参数。     

20000吨／年多聚甲醛生产工艺

项目简介： 根据国内需要，我们参考国外当前最先进的生产技术，开发了20000吨／年的多聚甲醛生产工艺，该工艺采用两级降膜浓缩、喷射造粒和连续干燥等技术，克服了国内釜式浓缩、耙式或刮片式干燥工艺所带来的生产规模小，原材料消耗高，产品质量差等缺点，使多聚甲醛生产的各项质量和消耗指标均达到了国外的先进水平。     

流化床干燥系统控制方案的优化

PVC流化床干燥工艺采用DCS单回路控制时,参数调整及时性和准确性差,系统控制依赖手动调节,能耗大。为解决以上问题,在流化床干燥工艺中引入动态解耦控制模型和循环神经网络模型,优化了干燥系统进料量和PVC树脂水含量,降低了蒸汽消耗。     

新型己二酸干燥设备的应用

主要介绍了在己二酸干燥中埋管流化床工艺上的改进,针对己二酸的物料特性,设计出适合己二酸干燥的埋管流化床,并成功应用于生产。     

小型化卧式振动流化床干燥系统的研制

分析了变性淀粉工业生产所用的气流干燥装置不能用在中试或者高校实验的原因,同时叙述了变性淀粉干燥设备应具备的条件及选择卧式振动流化床干燥作为中试用变性淀粉干燥装置的原因。设计了变性淀粉中试用小型化卧式振动流化床干燥系统的工艺设计方案,通过纯胶这种新型的变性淀粉进行干燥,从而验证了小型化卧式振动流化床干燥系统可行性及实用性。     

专利介绍

玻璃用石英砂原料流化床干燥方法；一种制备高分散性粉体材料的干燥粉碎工艺。     

温度对含结晶水无机盐流态化干燥的影响

提出了干燥介质温度与流化床干燥含结晶水无机盐的最大局域游离含水率影响的关系式,并提出了当局域游离含水率过大时改善流化状态的方法。可为流化床干燥含结晶水无机盐的工艺及其设备的设计提供参考     

DRYTNG OF PEPPER SEEDS USING A COMBINED MICROWAVE/FLUIDIZED BED DRYER

Abstract

The drying rates curves in terms of moisture content versus elapsed drying time for white pepper seeds were obtained experimentally using a fluidized bed and a combined microwave/fluidized bed. The combined microwave/fluidized bed employs a microwave field to assist convective drying. For both procedures, the drying rates were found to be dependent on the inlet air temperature and velocity. Significantly improved drying rates were achieved utilized a combined microwave/fluidized bed drying compared with a conventional fluidized bed.     

Measurement of constant drying rate of wet material placed in a fluidized bed of inert particles under reduced pressure

The objective of this study is to estimate the drying characteristics of a relatively large material immersed in a fluidized bed under reduced pressure by measuring the constant drying rate. The constant drying-rate period in a fluidized bed under reduced pressure is difficult to measure because it is extremely short. To maintain the constant drying-rate period, distilled water is directly supplied to the drying material. Through our experiment, the heat transfer coefficient of the material surface was also determined. The results were compared with data on hot air drying. The constant drying rate is higher for fluidized bed drying than for hot air drying. It suggests that the heat transfer coefficient on the surface of the drying material is much larger for fluidized bed drying than for hot air drying. For fluidized bed drying, the effect of pressure in the drying chamber on the heat transfer coefficient is slight at the same normalized mass velocity of dry air (G/G_mf). The temperature difference between the inside of the drying chamber and the drying material is much smaller for fluidized bed drying than for hot air drying. The constant drying rate increases as the pressure in the drying chamber decreases.     

湿污泥颗粒的流化床干燥实验及模型

在鼓泡流化床内以河砂为干燥介质,对单颗粒湿污泥的流态化干燥特性进行实验研究,得到了流化床温度、污泥初始水分、污泥粒径及流化速度对干燥速率的影响规律：流化床温度及污泥粒径对干燥速率的影响都呈指数规律;污泥的水分越大,干燥速率越大;在鼓泡流化床流化速度达到2倍临界流化速度以上时,充分流化,流化速度再增大(2~5倍临界流化速度)对干燥速率没有明显影响. 在基本的扩散传质理论的基础上,利用实验数据回归得到湿污泥在鼓泡流化床内干燥的半经验模型,为流化床污泥干燥器的设计提供了基础数据和依据.     

Drying Kinetics in the Riser of Circulating Fluidized Bed with Internals

Solid particles were dried in the riser of circulating fluidized bed with internals to study the drying kinetics. Experiments were conducted in a circulating fluidized bed, having perforated plates as internals covering wide range in the operating parameters. The effects of various operating parameters, i.e., initial moisture content, temperature, and flow rate, of the heating medium and solid circulation rate on the rate of drying have been critically examined. It has been observed from the present investigation that the presence of internals enhances the solids holdup in the riser of circulating fluidized bed. The drying efficiency of a circulating fluidized bed with internals has been compared with the drying performance of a circulating fluidized bed without internals under the same operating conditions.     

Drying Kinetics in the Riser of Circulating Fluidized Bed with Internals

Solid particles were dried in the riser of circulating fluidized bed with internals to study the drying kinetics. Experiments were conducted in a circulating fluidized bed, having perforated plates as internals covering wide range in the operating parameters. The effects of various operating parameters, i.e., initial moisture content, temperature, and flow rate, of the heating medium and solid circulation rate on the rate of drying have been critically examined. It has been observed from the present investigation that the presence of internals enhances the solids holdup in the riser of circulating fluidized bed. The drying efficiency of a circulating fluidized bed with internals has been compared with the drying performance of a circulating fluidized bed without internals under the same operating conditions.     

Drying of water treatment process sludge in a fluidized bed dryer

The drying characteristics of water treatment process (WTP) sludge were investigated with a fluidized bed. The equilibrium moisture ratio of WTP sludge increased with relative humidity and decreased with temperature of drying air. However, equilibrium moisture ratio of WTP sludge was more sensitively dependent on relative humidity than temperature of drying air. When the sludge was dried in a batch fluidized bed, the drying rate of sludge decreased as the moisture ratio of sludge in the bed decreased. The periods of constant drying rates were apparently not observed on the drying rate curves. In addition, the maximum drying rates were increased with bed temperature and superficial air velocity. As the fluidized bed was operated continuously, the degree of drying of WTP sludge increased with bed temperature but was weakly dependent on superficial air velocity. However, the drying efficiency was decreased with bed temperature and relatively insensitive to superficial air velocity and increased with feed rate of sludge.     

流化床干燥聚碳酸酯小试实验研究

使用流化床小试装置对聚碳酸酯粉料进行干燥,绘制聚碳酸酯干燥速率曲线,初步证明了卧式流化床干燥聚碳酸酯具有一定的可行性。     

Effect of Fluidizing Particle on Drying Characteristics of Porous Materials in Superheated Steam Fluidized Bed under Reduced Pressure

The hygroscopic porous particle was used as the fluidizing particle for the superheated steam fluidized bed drying under reduced pressure. A relatively large material was immersed in the fluidized bed as the drying sample. The drying characteristics of the sample were examined experimentally and the results were compared with those in the case of inert particle fluidized bed.

The water transfer from the sample to the fluidizing particle bed in the case of hygroscopic porous particle facilitated the drying regardless of pressure and temperature in the drying chamber. The increment degree of the sample temperature at the earlier period of drying was smaller in the case of hygroscopic porous particle than in the case of inert particle, and the phenomenon was more remarkable in the case of superheated steam than in the case of hot air.     

Effect of Fluidizing Particle on Drying Characteristics of Porous Materials in Superheated Steam Fluidized Bed under Reduced Pressure

The hygroscopic porous particle was used as the fluidizing particle for the superheated steam fluidized bed drying under reduced pressure. A relatively large material was immersed in the fluidized bed as the drying sample. The drying characteristics of the sample were examined experimentally and the results were compared with those in the case of inert particle fluidized bed.

The water transfer from the sample to the fluidizing particle bed in the case of hygroscopic porous particle facilitated the drying regardless of pressure and temperature in the drying chamber. The increment degree of the sample temperature at the earlier period of drying was smaller in the case of hygroscopic porous particle than in the case of inert particle, and the phenomenon was more remarkable in the case of superheated steam than in the case of hot air.     

垂直内挡板对流态化流体动力学及谷物干燥特性之影响

The effect of vertical internal baffles on the particle mixing and grain drying characteristics in a batch fluidized bed column is investigated. Experimental work was carried out in a 3 m high rectangular fluidized bed dryer of cross sectional area of 0.15 mx0.61 m at different operating conditions using paddy, a group D particle, as the fluidizing material. The results of the study showed that the fluidized bed dryer system with vertical internal baffles gave better particle mixing effect in the bed of particles than that without vertical internal baffles. This is due to the fact that the vertical internal baffle act as gas bubble breakers by breaking up the large gas bubbles into smaller ones. The smaller bubbles cause a more vigorous mixing in the bed of particles before finally erupting at the bed surface. This improves the contacting efficiency and enhanced the heat and mass transfer of the fluidized bed system. Thus a higher drying rate was obtained in the falling rate period because the higher contactin efficiency increases the evaporation rate at the particle surface. However, the drying rate in the diffusion regiol shows little improvement because the moisture diffusivity does not depend on the contacting efficiency. The fluidized bed dryer with vertical internal baffles could therefore be used in the initial rapid drying stage in a two stage drying strategy for paddy. The insertion of vertical internal baffles into a fluidized bed system improves the processing of Group D particles in a fluidized bed system especially if the system is large in scale.