双层烘缸表面温度的分布与探讨

介绍了双层烘缸的特点和类型,与传统烘缸对比,分析探讨了多通道双层烘缸表面温度分布不均的原因和机理。从改变烘缸外壁,改变烘缸组进出汽方式,分析离心力三个方面减小多通道烘缸表面温差,优化烘缸表面温度分布。     

落差循环机械烘干装置

<正>申请公布号:CN 106638101 A发明人:曾智丹申请人:桂林市森工机械技术开发有限公司设计一种利用高位自然落差使导热油循环加热烘缸的烘干装置。落差循环机械烘干装置如图1所示,在圆筒形烘缸内壁沿圆周均匀排列有不少于20个提油板,提油板为长条形状,与烘缸内壁连为一体,其作用是在烘缸旋转时将导热油提升到烘缸内壁上部。烘缸两端有端盖,左侧端盖中心有轴承,中心轴置于其中,右侧端盖中心有旋转密封器,套在出油管的外圆上。接油斗的形状为上大下小,底部固定在出油管     

双层烘缸表面温度分布不均的分析和优化

介绍了双层烘缸的特点和类型,与传统烘缸对比,分析探讨了多通道双层烘缸表面温度分布不均的原因和机理。通过建立离心力模型来分析烘缸表面温度变化,改变影响离心力的各因素,降低高温区的温度,缩小三个温区的温差,优化烘缸表面温度分布。     

具有相变恒温的导热油烘缸

申请公布号:CN 110592994 A 发明人:苏伟光 王丽 许崇海 高永法 秦士友 刘亚 李亚男 申请人:齐鲁工业大学 常用的烘缸有蒸汽烘缸、导热油烘缸、热辐射烘缸等,但以导热油和蒸汽为热源的烘缸表面温差较大,虽然目前经过结构改进,已经成功将温差降低。例如,山东鲁台集团枣庄市鲁都造纸机械有限公司发明的“一种旋转式多孔多腔导热油交换器”(申请号201810798729.6)利用导热油为热源,创新设计了一种旋转式多孔多腔导热油交换器,包括外筒、内筒、上封头、下封头,在内筒的外部套有一个外筒,内筒和外筒之间设有导油腔,内筒的两端与上封头、下封头连接.     

多通道烘缸表面温度的数值模拟与研究

运用CFD软件对多通道烘缸的单通道进行二维数值模拟,得到单通道内流体的温度分布和通道表面的温度分布,并分析了多通道烘缸两种结构的优劣。同时,对比不同入口压力对多通道烘缸表面温度的影响,结果表明,在相同的操作条件下,提高蒸汽进口压力,不仅可以提高多通道烘缸的干燥效率,还可以进一步改善烘缸表面温度。     

高速纸机烘缸轴承过早失效分析及改善研究

利用振动监测与故障诊断技术和油品分析技术对高速纸机前干燥部烘缸轴承进行监测跟踪,并对烘缸轴承的过早失效机理进行了研究。结果表明:烘缸轴承对润滑要求非常苟刻;润滑失效可致其过早失效;在不改变润滑油型号前提下,增大烘缸轴承座进油、排油温差,增大循环润滑油流量,促进带走烘缸轴承运行产生的热量,使润滑油工作实际黏度相对增加,有利于润滑油膜形成,从而延长烘缸轴承使用寿命。     

波纹薄型热板性能及设计优化研究

为改善瓦楞纸板生产过程中纸板的粘合烘干效果，提高纸板加热过程温度均匀性，优化现有波纹薄型热板结构，通过对现有波纹薄型热板进行结构理论分析以及Fluent流体有限元分析，根据分析出的结构缺陷进行进汽口、回水口位置以及进汽口数量优化。分析比较进汽口数量从1个到8个的加热过程中表面温差及流场特征，最终选取较为适宜的4个进汽口数量为初步优化方案。根据流场优化方法进行进一步结构优化，增设进汽口间挡板，利用Fluent流体有限元分析、产品试制以及现场测试对优化结构进行验证，有限元分析结果与未增设挡板相比，流场漩涡数量明显减少，现场测试结果最大温差改善81.8%，最小温差改善90%，表明优化结构在提高加热效率及降低产品成本的基础上，能够有效改善纸板加热均匀性，提高纸板质量。研究为改善瓦楞纸板生产的粘合烘干提供参考。     

纸机多通道烘缸的设计与受力分析

目前的造纸机烘缸大多采用虹吸管式冷凝水排出装置,由于受烘缸积水的影响,传统烘缸干燥效率下降,纸页受热不均匀。文章对该传统结构进行改造,采用多通道式冷凝排水装置,对新型多通道烘缸进行了理论分析,设计出新型多通道烘缸的通道、烘缸壁、缸盖。最后,应用ANSYS软件进行了多通道烘缸的受力分析,得出设计的多通道烘缸结构满足应力要求。多通道烘缸可改变原有排水方式,提高效率。     

热油加热烘缸

热油加热烘缸是以导热油作为加热介质的供缸。其结构与现在的蒸汽加热烘缸有所不同，导热油经油炉加热后进入烘缸内，通过调节阀门改变油流量，使烘缸表面获得所需的温度。经热交换后的导热油从回油管返回加热油炉稍加热后再循环使用。该运行系统简单：热油加热系统除热油加热炉、送油泵、烘缸外，没有锅炉、水处理设备。导热油在300℃基本不汽化，压力低可得高温，安全性好。投资省，天冷却水，热损失少，节约能源和人力。此项技术是沈阳造纸机械厂和沈阳市职工技术协作服务中。！合作研制成功的．已申报专利。热油加热烘缸     

多通道烘缸的传热模拟及优化

目前造纸机烘缸大多采用虹吸管式冷凝水排出装置,由于受烘缸积水的影响,传统烘缸干燥效率下降,纸页受热不均匀。基于此,对传统烘缸进行改造,设计出多通道烘缸的结构,文章应用FLUNET软件对不同高宽比的小通道进行了传热模拟,得到优化后的小通道尺寸值,结果表明小通道尺寸高、宽均为10 mm时,平均冷凝传热系数值最大,传热效率最高。对多通道烘缸进行尺寸优化有利于提高烘缸传热效率,节约能源。     

Comparison of Reticular and Rectal Core Body Temperatures in Lactating Dairy Cows

The Phase IV Cattle Temperature Monitoring System (CTMS; Phase IV Engineering Inc., Boulder, CO) marketed by MaGiiX (MaGiiX Inc., Post Falls, ID) uses a passive bolus equipped with a temperature sensor, a panel reader placed at a parlor entrance or exit to query the bolus, and a software package to collect, analyze, and view data. The biologically inert bolus resides in the cow's reticulum and is queried each time the cow passes the reader. Reticular temperature (RETT) and rectal temperature (RECT) were recorded simultaneously in the milking parlor exit lane in 4 consecutive milkings in each of 4 seasons, totaling 16 measurements per cow. The RETT were obtained by using the phase IV CTMS, whereas the RECT were obtained manually with a GLA M750 thermometer (GLA Agricultural Electronics, San Luis Obispo, CA). Data were edited to remove RETT likely to have been affected by a recent drinking bout. For the 2,042 observations used in analyses, means (±SD) were 39.28 (±0.41), 38.83 (±0.36), and 0.45 (±0.33) for RETT, RECT, and the difference between RETT and RECT, respectively. The RETT and RECT were strongly correlated (r = 0.645). The relationship between RETT and RECT varied by season, milking, housing system, and parity. Because dairy producers and veterinarians are accustomed to viewing rectal temperatures, equations to adjust reticular temperatures to a rectal-based scale may increase the utility of the phase IV CTMS. The resulting conversion equations were RECT = 19.23 + 0.496(RETT) for the a.m. milking and RECT = 15.88 + 0.587(RETT) for the p.m. milking.     

极端温度对三种扁谷盗属储粮害虫的致死作用

分析了42～62 ℃的极端高温、10～25 ℃的常规温度和-5～-15 ℃的极端低温对三种扁谷盗属害虫的致死作用,研究了极端低温下锈赤扁谷盗、长角扁谷盗和土耳其扁谷盗对温度的敏感差异性,评估了控温储粮技术防治扁谷盗害虫的可行性。在极端高温下, 54 ℃处理75 min、58 ℃处理60 min、62 ℃处理45 min能够完全杀灭锈赤扁谷盗成虫。在常规温度下,锈赤扁谷盗幼虫12 d死亡率低于30%,其死亡数量随时间的延长而增大。在极端低温下,长角扁谷盗对极端低温较为敏感,其次为土耳其扁谷盗、锈赤扁谷盗。极端温度防治害虫的有效性取决于有效的温度、足够的暴漏时间和处理物料的安全性。极端低温通常比极端高温需要更长的暴露时间,但长时间暴露在极端温度下被处理商品受损的风险将进一步增大。     

皮革收缩温度的检测与实现

论述了以单片机为核心的皮革收缩温度测试系统 ,水平放置被测试片、用VMIC变模式控制升温速率。实测证明 :测试结果的一致性、准确度均优于已有的测试方法。     

磨削温度研究的现状与进展

从磨削温度的理论研究和磨削温度的测量技术两个方面，概要介绍了磨削温度的研究现状。探讨了磨削温度理论研究的发展趋势，比较了目前常用的几种磨削温度测量技术的优缺点。     

精准温控贮藏对西兰花采后品质和生理变化的影响

为了探究西兰花在不同贮藏温度下的生理变化与品质差异,分别用普通冰箱[(4.0±1.0)℃]、精准温控的冰温库[(-0.5±0.3)℃]和相温库([(-0.4±0.1) ℃]3种环境贮藏采摘后的西兰花。结果表明:经过冰箱冷藏的西兰花贮藏期可达30d,30d后可溶性固形物、叶绿素、维生素C、可溶性蛋白含量下降,品质逐渐劣变;精准温控(冰温与相温)贮藏的西兰花70d后色泽饱满,营养物质含量丰富,呼吸强度与乙烯生成速率较小,且腐烂率与黄化指数处于较低水平,体现较高的超氧化物歧化酶及过氧化氢酶活性,膜质受损程度较轻、机体防御体系较强。冰温与相温贮藏60d时,西兰花维生素C质量分数分别为37.70、46.53mg·100g-1,黄酮质量分数分别为12.30、15.56mg·100g-1,过氧化氢酶活性分别为67.20、120.00U·g-1;在70d时,西兰花呼吸强度分别为463.79、416.90mg·(kg·h)-1,乙烯生成速率为83.37、63.07μL·(kg·h)-1,超氧化物歧化酶活性分别为1543.91、1588.55U·g-1。相比较冰温,相温贮藏能延缓西兰花维生素C及黄酮含量下降,抑制其呼吸强度和乙烯生成速率,使得超氧化物歧化酶和过氧化氢酶活性处于较高水平(P<0.05)。精准温控(冰温与相温)贮藏可控制西兰花的生理变化,有效延缓其采后品质下降的速率,相温贮藏优于冰温贮藏。     

Technical note: Assessment of milk temperature measured by automatic milking systems as an indicator of body temperature and fever in dairy cows

The objective of this study was to evaluate whether milk temperature (MT) measured by automatic milking system (AMS) is a reliable indicator of body temperature of dairy cows and whether cows with fever could be detected. Data loggers (Minilog 8, Vemco Ltd., Halifax, NS, Canada) measuring body temperature were inserted for 7 ± 1 d into the vaginal cavity of 31 dairy cows and programmed to take 1 reading/min. Milk temperature was recorded at each milking event by the AMS, and values from the vaginal loggers were paired with the corresponding MT. The correlation (r) between vaginal temperature (VT) and MT was 0.52. Vaginal temperature was higher (39.1 ± 0.4°C) than MT (38.6 ± 0.7°C) with a mean difference of 0.5 ± 0.6°C. The ability of MT to identify cows with fever was assessed using 2 approaches. In the first approach, VT could indicate fever at any time of the day, whereas MT could display fever only during the milking events of a given day. Different definitions of fever based on thresholds of VT and duration exceeding these thresholds were constructed. Different thresholds of MT were tested to distinguish between cows with and without fever. The combination of 39.0°C as a threshold for MT and 39.5°C for at least 2 h/d as a threshold for VT resulted in the highest combination of sensitivity (0.65) and specificity (0.65). In the second approach, we evaluated whether MT could identify cows with fever at a given milking event. A threshold of MT >38.7°C delivered the best combination of sensitivity (0.77) and specificity (0.66) when fever was defined as VT ≥39.5°C. Therefore, MT measured by AMS can be indicative of fever in dairy cows to a limited extent.     

基于AD590的发酵罐多点温度测量系统

为开发啤酒、制药等行业所需的端面测温传感器,利用自制的能测量多点温度的传感器,采用集成温度传感器AD590作为测温元件,依据其温度特性并通过其接口电路和集成温度传感器矩阵网络以及单片机微功耗技术,系统研究发酵罐内的温度分布,设计了一种新型的温度测量系统.该系统只需将传感器信号引入,无需再作其它调整就可完成高精度的多点温度测量.     

R404A/R23复叠式超低温制冷系统试验

依托自建的R404A/R23复叠式超低温制冷试验台,采用控制单一变量的方法,研究蒸发温度与冷凝温度对复叠式制冷循环中压缩机压缩比、排气温度、吸气压力、制冷剂流量和制冷系数的影响。结果表明:当蒸发温度从-50℃降至-55℃时,系统制冷系数下降最快,达到2.1%;当冷凝温度从28℃升至30℃时,系统制冷系数下降最快为1.7%,且蒸发温度下降1℃比冷凝温度上升1℃对系统性能系数影响更大。另外,当蒸发温度为-55℃,冷凝温度为36℃时,压缩机排气温度达到最高90℃,此时,系统性能系数最低为1.5,所以,有效控制压缩机排气温度对系统安全和高效运行至关重要。     

Impact of intake water temperatures on reticular temperatures of lactating dairy cows

Automatic temperature recording may allow early detection of disease, estrus, heat stress, and the onset of calving. The phase IV Cattle Temperature Monitoring System (MaGiiX Inc., Post Falls, ID) utilizes a passive bolus equipped with a temperature sensor, a stationary panel reader to query the bolus, and software to collect, analyze, and display data. One potential limitation to collection of reticular temperatures is the effect of water temperature and consumption on recorded temperatures. Two replicated 3 × 3 Latin square experiments were conducted at the Purdue Dairy Research and Education Center to assess the impact of water intake on reticular temperatures using the Cattle Temperature Monitoring System. Nine high-producing, mid-lactation, second-parity cows with low somatic cell counts were selected. Before administering a water treatment, access to feed and water was restricted for at least 2 h. Baseline reticular temperatures were established from measurements before water intake. In experiment 1, treatments were 25.2 kg of hot water (34.3°C ± 1.0), warm water (18.2°C ± 0.4), or cold water (7.6°C ± 0.4). In experiment 2, treatments were 18.9 kg of body-temperature water (38.9°C ± 0.2), cold water (5.1°C ± 0.4), or control (no water). Following water intake, reticular temperatures were collected for 3 h. In experiment 1, an initial dramatic decrease in reticular temperature was observed followed by a gradual increase toward baseline. Least squares means for maximum drop in temperature were 8.5 ± 0.5, 6.9 ± 0.5, and 2.2 ± 0.5°C for cold, warm, and hot water treatments, respectively. Yet at 3 h, reticular temperatures did not return to the baseline. In experiment 2, control cows remained within the baseline confidence interval through the observation period, and cows receiving body temperature water experienced an initial decrease in temperature (0.4 ± 0.2°C) with a return to within the baseline confidence interval within 15 min. Cows receiving cold water did not return to within the baseline confidence interval after a large decrease of 9.2 ± 0.2°C during the 3-h observational period. Moreover, a regression analysis of continued ascent in temperatures predicted that temperatures would return to baseline within 3.5 h. These results demonstrate that, when cows consume large quantities of cold water, the effect of water intake is sizable and sustained. The value of reticular temperatures for daily monitoring in a production setting hinges largely on the implications of this impact.     

典型食品物料的共晶、共熔温度研究

实验研究和分析结果表明一些典型食品物料的共晶温度比共熔温度低;共晶曲线比共熔曲线的斜率变化大;物料晶核形成阶段的电阻变化率小于物料大冰晶成长阶段的电阻变化率,进而又小于物料共晶阶段的电阻变化率。从理论上初步探讨了汤料的共晶、共熔温度与物料的物性、胶体结构及盐度有关。因此通过改变物料的胶体结构和盐度可降低被冻结物料的熔点,进而降低冻结能量的消耗。