烟囱除尘器的除尘效率测定方法

本刊1985年第4期上报导了“固定层煤气发生炉烟囱的改进”一文后,作者陆续收到一些兄弟厂的信件,讯问烟囱除尘器除尘效率的具体测定方法。为了满足兄弟厂的要求,现征得湘江氮肥厂李永恒同志有关除尘效率的测定方法一文并介绍于后,供大家参考。     

半水煤气生产中吹风气烟尘的治理

在间歇式固定层煤气发生炉的吹风气中,含尘量很大污染环境相当严重,为解决这个问题,我厂在烟道伐的后面,烟囱的前面安装了“冲击式惯性水力除尘器”。经一年来的使用,认为这种除尘器结构简单,制作容易,维修最小,比较耐用。而且对负荷的适应性强,阻力小,除尘效果比较高,能满足环保要求。     

烟囱的环保设计简述

水泥厂烟囱高度的计算,已不单纯从满足工艺生产的需要,还应满足环保的要求进行计算确定。文章着重阐述了烟囱高度的计算模式(其计算方法分为二步:第一步,烟囱抬升高度;第二步,依照大气扩散的数学模式以保证大气质量为标准来确定必要的烟囱高度。)以及计算模式中输入参数(大气质量控制标准、大气风速、大气稳定度等)的讨论。通过实例(以水泥厂5000t/d熟料生产线为例)演示计算出窑尾烟囱和冷却机烟囱的高度。生产实践表明,严格按照国标规定的要求进行设计计算烟囱的高度,是能满足环保要求的。     

煤气炉烟囱防腐蚀和除尘器应用

本文综述了国内中、小型氮肥厂固定层煤气发生炉烟囱的腐蚀原因及其防腐蚀措施,并对烟囱除尘器的种类及其效果进行了评述。     

离线清灰低压脉冲袋式除尘器在余热发电除尘系统中的应用

前言 我公司有两条2500t／d带余热发电的干法回转窑，发电机功率为1．2kW。因回转窑余热热能满足不了发电机功率要求，配置35t／h燃煤锅炉1台。该锅炉烟气除尘原为水膜除尘系统，其除尘工艺流程为：锅炉→石块砌筑的进气管道→水膜除尘器→引风机→出气管道→烟囱→大气。在除尘过程中，由于粉煤灰潮湿，     

BETH电子脉冲袋式除尘器国产化

大化集团公司碱业股份公司包装岗位，使用的进口电子脉冲袋式除尘器，较同岗位使用的国产ＭＣ－１２０Ⅱ型除尘器有许多优越性。在大化集团公司的重质纯碱生产装置中，我们对进口的ＢＥＴＨ电子脉冲除尘器进行了国产化。     

石油化工行业烟囱筒节更换施工技术

石化、化工行业的钢结构烟囱更换项目施工作业空间小、施工安全风险高、危险性大,介绍了使用吊车配合,用倒拆、倒装法更换烟囱筒节的施工技术,保证了烟囱框架的整体安全稳定性、降低施工安全风险,并缩短了工期,满足生产装置检修工期要求。     

水泥厂烟囱设计公式的分析与实践

以叙利亚ABC项目中的窑尾烟囱设计为实例,根据经验初步设定烟囱几何高度和烟囱直径,利用常用的几个烟气抬升高度计算公式以及烟囱几何高度确定方法,得出了烟囱几何高度和烟囱直径的适宜值,最后通过对烟囱的系统阻力和排放污染物浓度的计算,说明所设计的烟囱满足排放要求和环保要求。     

高效褶皱布袋在焦炉装煤除尘器中的应用

为保证除尘器烟囱排放达到10 mg/m~3超低排放标准,通过方案对比,使用高效褶皱布袋,在不改变除尘器本身结构的前提下,不仅排放指标合格,除尘器运行技术经济指标也得到了有效改善。     

大直径滚筒式干燥机在土城矿选煤厂的应用

针对大直径滚筒式干燥机在土城矿选煤厂应用中出现的问题,对干燥系统除渣机、水膜除尘器污水收集泵、滚筒内破碎网、除尘器排灰系统、干燥机滚筒固定端、引风机等进行了改造,提高了系统处理能力,满足了选煤厂生产要求,取得了较好的经济效益。     

DESIGN, EXPERIMENTAL AND ECONOMIC EVALUATION OF A COMMERCIAL-TYPE SOLAR DRYER FOR PRODUCTION OF HIGH-QUALITY HAY

Design features, development, experimental functional performance and economic evaluation of an energy efficient solar energy dryer for commercial production of high-quality hay and processed forage products are presented. The solar hay dryer consists of an improved solar collector with selective coated aluminum absorber plate and spaced fins, and a drying shed connected to the collector by an insulated duct and having a perforated metal grate floor, swing-away plywood frames and polyethylene curtains for effectively sealing the hay stack, and a crawl space below the floor where a 3-hp in-line centrifugal fan is housed for air circulation by suction. In late August and in early September, 1996, 160 small rectangular bales of alfalfa hay with about 25% bromegrass were successfully dried from 33% initial moisture content to 13%, and from 25% to 11% moisture in 4 and 3 days, respectively, under average weather conditions in Saskatoon, Saskatchewan, Canada. With about 18 m³/min per tonne airflow, 10-15 °C temperature rise above ambit was obtained during peak bright sunshine hours. Relatively high daily average collector Effciency of 76%, high drying effectiveness, drying uniformity, uniform air distribution and tight sealing of the stack were achieved which resulted in an attractive green color of hay, no mold growth on hay, and an overall system drying efficiency of about 79%. Compared to a conventional natural gas drying system or field-drying method, the payback period on extra investment costs recovered through drying cost savings of $3/ t to $6/ t or through over two times higher prices for high-quality hay produced by the solar drying system may be just one or two years, respectively.     

DESIGN,EXPERIMENTAL AND ECONOMIC EVALUATION OF A COMMERCIAL-TYPE SOLAR DRYER FOR PRODUCTION OF HIGH-QUALITY HAY

Abstract

Design features, development, experimental functional performance and economic evaluation of an energy efficient solar energy dryer for commercial production of high-quality hay and processed forage products are presented. The solar hay dryer consists of an improved solar collector with selective coated aluminum absorber plate and spaced fins, and a drying shed connected to the collector by an insulated duct and having a perforated metal grate floor, swing-away plywood frames and polyethylene curtains for effectively sealing the hay stack, and a crawl space below the floor where a 3-hp in-line centrifugal fan is housed for air circulation by suction. In late August and in early September, 1996, 160 small rectangular bales of alfalfa hay with about 25% bromegrass were successfully dried from 33% initial moisture content to 13%, and from 25% to 11% moisture in 4 and 3 days, respectively, under average weather conditions in Saskatoon, Saskatchewan, Canada. With about 18 m³/min per tonne airflow, 10-15 °C temperature rise above ambit was obtained during peak bright sunshine hours. Relatively high daily average collector Effciency of 76%, high drying effectiveness, drying uniformity, uniform air distribution and tight sealing of the stack were achieved which resulted in an attractive green color of hay, no mold growth on hay, and an overall system drying efficiency of about 79%. Compared to a conventional natural gas drying system or field-drying method, the payback period on extra investment costs recovered through drying cost savings of $3/ t to $6/ t or through over two times higher prices for high-quality hay produced by the solar drying system may be just one or two years, respectively.     

水平堆垛在浮法玻璃生产线冷端的应用

在目前浮法玻璃的生产中,水平堆垛机是应用在生产线上重要的机电一体化设备,可智能、自动的将玻璃原片从生产线上取下并堆垛到玻璃架上。介绍了水平堆垛机工作原理、构成及各部件功能,水平堆垛机实现了触摸屏可视控制,界面友好,操作方便,降低了生产成本,系统灵活、精确。     

新型捕收剂H_(917)的工业试验

新型捕收剂H_(917)是由棉子油下脚皂化物与BH-5捕收剂混合制备而成。用于锦屏磷矿的工业试验,实现了常温浮选,取得了与原选矿工艺相近的生产指标,可节省2/3矿浆加温用煤,经济效益显著。     

Effect of current collector corrosion made from printed circuit board (PCB) on the degradation of self-breathing direct methanol fuel cell stack

Adopting printed circuit board (PCB) as the current collector for direct methanol fuel cell (DMFC) is a promising task. This paper found that the combinational 10 μm Ni/2 μm Au coatings on PCB could not endure halide attacking in its anodic polarization. With this coated PCB, the self-breathing DMFC stack with passive methanol supply exhibited progressively degradation in its lifetime test. By using a series of measurements, it is shown that initial corrosion would not obviously influence stack degradation, but the subsequently inter-facilitation, between F⁻ originating from Nafion membrane and corrosion products of Ni²⁺ and Cu²⁺ from PCB, would result in serious degradation, the final stack invalidation would present accompanied with the loss of membrane conductivity. The defects on coated PCB are crucial to initiate localized corrosion and stack degradation. Although cyclic voltammetry (CV) technology is effective to recover cell temporarily, its damage by releasing F⁻ should be further evaluated.     

H_(907)磷矿捕收剂的研究与应用

H_(807)是聚乙烯醋酸酯与磺化甲酯盐混合而得的一种磷灰石型矿石的聚-复型捕收剂。本文介绍了该药剂的制造工艺及应用情况。实践证明,在常温中性介质条件下该药剂对磷灰石具有较强的捕收能力。     

沙特某钙质磷矿不脱泥直接浮选的试验研究

用复合捕收剂对沙特某钙质磷矿石进行不经脱泥的直接浮选,一步反浮选后,精矿品位P2O5达32.57％,回收率为92.41％,达到设计要求,克服了原有捕收剂要求原矿脱泥处理后才能浮选的缺点.研究了磨矿细度、捕收剂用量、表面活性剂用量及选矿废水循环利用对浮选指标的影响.     

Experimental and numerical studies of portable PEMFC stack

The objective of this work is to establish the design principles of a proton exchange membrane (PEM) fuel cell (FC) stack for portable applications. A combination of experiments and numerical simulations were carried out and the results analyzed to enhance understanding of the behavior of this portable PEMFC stack. A three-dimensional (3D) computational fluid dynamics (CFD)-based methodology was used to predict such as the current and temperature distributions of this portable PEMFC stack. The results show how the baseline operation and original design of this stack impact the local temperature, water content, water transport, and kinetic variables inside the individual cells. The outcome of this work will pursue the development of universal heuristics and dimensionless numbers correlated to portable PEMFC stack design.     

Portable Size DMFC‐Stack

A small, low temperature, direct methanol fuel cell stack for portable applications has been developed. Several flow field designs were investigated with respect to stable operation and high performance. Due to carbon dioxide and water production on the anode and cathode, respectively, methanol and oxygen access to the electrodes is hindered. During single cell operation the effect of both carbon dioxide evolution and water production on the current output was observed. The difference between parallel and serial feeding of both fuel and oxidant to the DMFC stack was also investigated. It was found that it is very important to remove reaction products from the active cell surface in order to ensure stable stack operation at low temperatures. The maximal power realised with the 12‐cell direct methanol fuel cell stack was 30 W.     

Model Predictive Control with Feedforward Strategy for Gas Collectors of Coke Ovens

In coking process, the production quality, equipment life, energy consumption, and process safety are all influenced by the pressure in gas collector pipe of coke oven, which is frequently influenced by disturbances. The main control objectives for the gas collector pressure system are keeping the pressures in collector pipes at appropriate operating point. In this paper, model predictive control (MPC) strategy is introduced to control the collector pressure system due to its ability to handle constraint and good control performance. Based on a method proposed to simplify the system model, an extended state space model predictive control is designed, which combines the feedforward strategy to eliminate the disturbance. The simulation results in a system with two coke ovens show the feasibility and effectiveness of the control scheme.