企业讯息

<正>嘉宝莉研究水性木器漆微波红外干燥技术随着人们对环境污染的日益重视,更具环保性能的水性木器漆逐渐得到家具行业、企业的关注,但是干燥难等技术问题却成为了该产品发展中的难题,对此嘉宝莉涂料公司新近研发出一种微波红外干燥技术。据公司介绍,红外和微波都具有穿透性,红外加热能温和地烘干水分,而微波则可以快速而彻底地完成对水分的烘干,二者相结合既能够满足对水性漆干燥速度的要求也     

天然胶乳厚胶膜热风干燥与红外干燥对比研究

采用失重法研究了天然胶乳厚胶膜在热风与红外线两种干燥方式下的干燥过程。研究结果表明,在相同条件下,红外干燥的干燥速率常数远大于热风干燥,采用红外干燥可大大缩短干燥时间,干燥温度和厚度均显著影响干燥过程,红外干燥对温度更敏感。通过动力学拟合结果,得到了干燥动力学方程,可以预测干燥时间。     

采用远红外加热技术干燥聚酯切片

介绍了采用远红外线加热干燥含水切片的试验过程,分析了此项技术的可行性。通过试验测试了不同的加热温度、料板距离和干燥时间对干燥后切片含水率的影响。试验结果表明,采用远红外线加热干燥后的切片含水率是可以达到螺杆挤压机纺制聚酯短纤维和熔喷非织造布的工艺条件和技术要求的,从而扩大了远红外线的应用范围。     

微波加热技术应用于复混肥料中钾含量测定的研究

四苯硼钾重量法测定复混肥中钾含量过程中处理样品采用的普通电热板加热技术存在耗时耗能、不利于快速分析等缺点,将具有可以快速溶解试样和快速干燥特点的微波加热技术应用于复混肥中氧化钾含量的测定。实验结果表明,可以采用微波中高火5 min溶解试样的方法替代电热板加热溶解试样的方法;较适宜微波干燥时间为12 min;该微波加热方法的精密度及加标回收率（99.66%～100.58%）均达到要求,缩短分析时间1.5 h,节约能耗60%～70%,有利于快速指导生产,促进产品质量稳定。     

短波红外加热技术在连续板钢生产线上的应用

短波红外加热技术具有高效、清洁、安全、控制精度高、占地少及操作维护简便等特点,因此其在板钢生产线上的应用有逐步扩大的趋势。对于电力资源丰富、而燃气缺乏的企业,要进行普通产品的加热干燥生产,短波红外加热技术显然应是首选。而对于空间狭窄的老机组的改造,短波红外加热技术更能体现“即插即用”的优势。     

红外辅助冷冻干燥装置摔制系统的研发

真空泠冻干燥产品质量优异,广受青睐,但其干燥速率慢、耗能较大,制约其在普通产品干燥的推广应用。本文基于红外辅助加热和搁板传导的结合,提高对物料加热的有效性。并研发了红外辅助冷冻干燥装置的控制系统,以实现对物料冻结和加热的可控性和用户友好操作。     

不同加热功率下含油污泥的干燥

辽河油田的含油污泥含有大量的水分,为了更有效地进行油泥热解和减少热解过程中的能耗,需运用干燥技术处理油泥。实验考察了不同干燥功率对油泥干燥速率、湿分比的影响。实验结果表明:油泥干燥可以分成3个阶段,即恒速干燥阶段、第1降速干燥阶段和第2降速干燥阶段;加热功率越大,达到平衡含水质量分数所用的时间越短,恒速干燥速率越大。然后运用干燥方程求得干燥时间。最后运用热分析动力学对实验数据进行处理,得到干燥动力学的数学模型。模拟结果表明修正Page模型符合油泥干燥过程。     

天然气催化燃烧在红外加热技术方面的应用

介绍了天然气催化燃烧红外辐射加热技术在工业上的应用和研究现状。该技术克服了一般天然气红外辐射加热燃烧温度高、容易回火、NOx、CO和UHC排放量高等缺点,通过粮食处理、喷漆干燥和杀灭害虫等实例说明该技术在工业中的广泛应用。该技术常用催化剂为纤维催化剂,催化剂活性组分为Pd或Pt,载体纤维包括陶瓷纤维、玻璃纤维和金属纤维等。纤维催化剂气体阻力小,比表面积大,容易成形和安装,其研究和开发较快,并得到广泛应用。     

注射成型快变模温技术研究进展

快变模温技术是新型绿色注射成型技术。通过对模温的动态控制,可以有效地消除制品熔接痕,减少制品残余应力。介绍了快变模温技术的原理,对电加热、蒸汽加热、电磁加热、红外加热等多种加热方式进行分析。最后对快变模温技术发展前景作出展望。     

远红外线加热干燥技术简介

一、前言远红外线加热干燥技术是七十年代发展起来的一项新技术,它具有高效快干,干燥均匀,省电,占地面积小等特点,而且设备简单,投资少,容易上马,是一种很好的加热干燥方法。据介绍远红外线干燥,时间可缩短到近红外线的二分之一,热风干燥的十分之一左右,烘道可缩短到原来的1/2～1/10,可以节约用电20～60％左右。所以远红外线加热干燥技术是很受人们重视的一门新技术。     

Trends in Microwave-Assisted Freeze Drying of Foods

Microwave-assisted freeze drying (MFD) can be accomplished in two distinct ways: freeze drying assisted concurrently with microwave application (MFD-1) and freeze drying and assisted microwave/vacuum microwave drying in two consecutive separate drying stages (MFD-2). MFD is a rapid dehydration technique that can be applied to certain foods, particularly to seafoods, solid soup, and fruits and vegetables. MFD involves much less drying time and energy consumption than conventional freeze-drying methods. Currently, this technology has been successfully used to dry many food materials and has potential in the food industry. Increasing concerns over product quality, energy savings, and production costs have motivated researchers and the industry to adopt MFD technologies. The advantages of MFD include shorter drying time, energy savings, improved product quality, and flexibility in producing a wide variety of dried products. However, current applications are limited to small categories of foods due to high startup costs and relatively complex technology compared to conventional freeze drying. This article presents a concise review of recent progress in MFD R&D and makes recommendations for future research to bridge the gap between laboratory research and industrial applications.     

Effect of infrared pretreatment on low-humidity air drying of apple slices

The dried apple is used in the preparation of weaning foods and bakery products. The current drying processes, especially hot air (HA) drying, still face the problem of longer processing time and product quality degradation. The low-humidity air (LHA) drying can be an option to retain product quality in heat-sensitive food such as apple. The present work focuses on the effect of pretreatment of apple slices with potassium metabisulfite and infrared (IR) waves on drying characteristics when subjected to LHA drying and comparing the product quality with conventional hot air and freeze drying (FD). Pretreatment with IR waves reduced the drying time by nearly 23 and 17% in LHA and HA drying, respectively. The results indicated that IR-treated and LHA-dried slices retained nearly 82–90 and 72–74% of ascorbic acid and total phenolic content, respectively and was comparable to FD slices. The drying time for LHA was nearly 37% lesser than that for HA drying. LHA-dried apple slices had better color and rehydration ratio compared to FD- and HA-dried slices.     

Modularer Trocknungsprozessor zur Anwendung kombinierter Trocknungsverfahren

A modular drying processor for the development of energy and time efficient combined drying processes was constructed. It allows the serial and/or parallel application of different drying methods such as freeze‐, hot‐air‐, infrared‐, contact‐, microwave‐ or vacuum‐drying without interruption between the processes. Depending on the drying method precise product structures could be achieved by using the example of carrot cubes. The serial combination of freeze‐ and microwave vacuum drying shortened the process time about 40 % while highest product quality was obtained.     

新型高能效沸石吸附食品干燥器的开发

人们对接近新鲜状态的高质量干燥产品的需求越来越显著。当代干燥技术在提高产品质量方面有显著的进步,但在设备节能方面鲜有突破。利用沸石等吸附剂进行空气脱湿是提高干燥效率的一个很有潜力的选择。在此方法中,沸石与干燥介质空气接触,可使空气中水蒸气很快地减少到0．1ppm或露点温度降到-50℃;同时释放吸附热使得空气温度不断升高。从而,干燥器入口空气含有较多的用于干燥的显热,提高了干燥驱动力和总能效。本文讨论了沸石吸附干燥卡拉胶和玉米的应用,实验结果表明吸附干燥方法提高了产品质量,同时缩短干燥时间。然而,在商业应用之前需要进行深入的可行性研究。     

The drying strategy of atmospheric freeze drying apple cubes based on glass transition

Freeze drying (FD) yields the best quality of dried apple cubes but at the cost of long drying time and also the overall cost. To achieve economical freeze drying along with a high quality product an atmospheric freeze drying (AFD) technique was developed to dry apple cubes. The effect of different air temperature loading scheme on product quality and drying process was studied during AFD. According to the glass transition temperature of apple, a step-up temperature loading strategy for AFD process was developed to reduce the drying time by almost half and provided a similar good product quality.     

OPTIMIZATION OF OPERATING CONDITIONS IN TUNNEL DRYING OF FOOD

Food drying process in tunnel dryer was modeled from Keey's drying model and experimental drying curve, and optimized in operating conditions consisting of inlet air temperature, air recycle ratio and air flow rate. Radish was chosen as a typical food material to be dried, because it has a typical drying characteristics of food and quality indexes of ascorbic acid destruction and browning in the drying. Stricter quality retention constraint required higher energy consumption in minimizing the objective function of energy consumption under constraints of dried food quality. Optimization results of cocurrent and counter current tunnel drying showed higher inlet air temperature, lower recycle ratio and higher air flow rate with shorter total drying time. Compared with cocurrent operation counter current drying used lower air temperature, lower recycle ratio and lower air flow rate, and appeared to be more efficient in energy usage. Most of consumed energy was analyzed to be used for air heating and then escape from the dryer in form of exhaust air.     

Parametric Study of High-Intensity Ultrasound in the Atmospheric Freeze Drying of Peas

Atmospheric freeze drying (AFD) is a dehydration process that can be used to produce high-end products for the food, pharmaceutical, and biological industries. Evaporation or sublimation at the drying temperatures used for these processes is generally low. Airborne ultrasound can be used to increase drying rates. This parametric study investigates the influence of the drying temperature, drying time, and ultrasonic power for atmospheric freeze drying in the presence of an airborne ultrasonic field. Accelerated effective diffusion of up to 14.8% was obtained for atmospheric freeze drying with a fluid bed. The faster drying in ultrasonic-assisted atmospheric freeze drying is assumed to be due to a higher mass transfer rate at the solid-gas interface, caused by a reduced boundary layer due to a higher turbulent interface. Thus high intensity, airborne ultrasound used with modern drying systems has great potential to accelerate drying, reduce investment and production costs, and improve product quality.     

OPTIMIZATION OF OPERATING CONDITIONS IN TUNNEL DRYING OF FOOD

ABSTRACT

Food drying process in tunnel dryer was modeled from Keey's drying model and experimental drying curve, and optimized in operating conditions consisting of inlet air temperature, air recycle ratio and air flow rate. Radish was chosen as a typical food material to be dried, because it has a typical drying characteristics of food and quality indexes of ascorbic acid destruction and browning in the drying. Stricter quality retention constraint required higher energy consumption in minimizing the objective function of energy consumption under constraints of dried food quality. Optimization results of cocurrent and counter current tunnel drying showed higher inlet air temperature, lower recycle ratio and higher air flow rate with shorter total drying time. Compared with cocurrent operation counter current drying used lower air temperature, lower recycle ratio and lower air flow rate, and appeared to be more efficient in energy usage. Most of consumed energy was analyzed to be used for air heating and then escape from the dryer in form of exhaust air.     

Effect of freeze dried,hot air dried and fresh onions on the composition of volatile sulfocompounds in onion oils

The bioactivity of onion, particularly its oil, has gained increasing research attention. Preparation of onion oil is challenging due to its low oil content and abundance of water. In this study, pilot-scale drying combined with laboratory extraction was conducted for sample preparation. GC/MS and solid phase microextraction (SPME) analyses were performed to evaluate the correlation between onion oil and drying. Results showed that drying significantly influenced the sulfocompounds composition of onion oils. Dipropyl disulfide and dispropyl trisulfide were the most abundant compounds in fresh onions (accounting for 68.41% to 93.13% of the total volatile sulfocompounds). The total contents of sulfocompounds in vacuum freeze dried and hot air dried onion powder were 4.96% and 39.79%, respectively, which account for 24.59% to 48.89% of the total content. Dimethyl sulfides and thiophenes were the main compounds in the onion oils. The highest content of sulfocompounds was obtained in the oil of hot air dried powder. Pilot-scale hot air drying was the optimal pretreatment method for onion oil extraction. It enjoys lower energy lost, shorter process time, and higher quality of the oil compared with freeze drying. The results may be helpful for onion oil production and bioactivity evaluation.