范文一:船用分油机
WORKING DRAWING
******************************************
PROJECT : 75,200DWT BULK CARRIER
SHIPYARD : PENGLAI ZHONGBAI JINGLU SHIP INDUSTRY CO., LTD. HULL NO. : JL0019(B)/JL0020(B)
MANUFACTURE: ALFA-LAVAL
ITEM : M/E LO SELF CLEANING FILTER
TYPE: X-280D-50/8-A06 --------------------1 SET/SHIP
L-280-345-A07 ---------------------1 SET/SHIP CLASSIFCATION : BV
AUTOMATIC LO FILTER FOR CROSSHEAD ENGINE
TECHNICAL SPECIFICATION
DATA VALUE
Diesel engine type
Auto L.O.Filter Type X-280-D-50/8(A06) Max. filter capacity (Q1) m3/h 312
Pump Capacity (QP) m3/h 270
Flow to Engine(QE) m3/h 261.9
Flow of back-flushed oil (Q3) m3/h 8.1
Filter fineness:(Absolute) μm 40
(Nominal) μm 25
Max. Filter inlet press (P1 max) bar 12
Min. Filter outlet pressure (P2 min) bar 1,4
Normal filter outlet pressure (P2 norm) bar 2 - 4
Max. counter pressure (P3 max) in “ return to sump”
For P2=2-4 bar --------------------(P3 max) For P2=1.4-2 bar------------------(P3 max) bar
bar
0.5 0.2
Normal Pressure Drop (P1-P2) bar 0.2-0. 5
Alarm Pressure Drop (P1-P2) bar 0. 8
Min. Required Pressure Difference Between Filter
Outlet (P2) and “ return to sump” (P3) (P2-P3)
Max. temperature in the filter ℃ 100
Max. Viscosity in the Filter at Normal Operation cSt 130
Back-flushing flow (% of pump capacity QP) % 3
Mounting position Vertical
Test pressure 24 bar
Housing material Nodular cast iron
MANUAL LO FILTER FOR CROSSHEAD ENGINE
LO filter type L-280-345(A07) Max. filter capacity (Q1)m3/h334
Filter fineness : (Absolute)μm 45
(Nominal)μm 30
Page 1
DUPLEX AUTO / MANUAL LO FILTER
====
r
e
Key: QP Lube oil pump capacity Q1 QE Q3 P2 P3 = Back-flushed oil outlet pressur Max. capacity of the filte Lube oil flow to the engine Flow of back-flushed oil Clean oil outlet pressure
·
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Protector X-280-D 50/8 to 80/8 Counter flanges
COUNTER FLANGES DIMENSIONS
Protector Connection DN d1 D x EQtyxd2xk d5xd6xp C. flange O-ring
Return to sump
200x201800-05487 X-280-D-50/8
X-280-D-60/8
X-280-D-80/8 Inlet and outlet 395x2612x22x3501800-05413 O-RING DIMENSIONS
Art. No
d3 x d4 291.47x7 113.67 x 6
Page 3
Protector L-280 345 Counter flanges
COUNTER FLANGES DIMENSIONS
Protector
DN
d1
D x E
Qtyxd2xk
d5xd6xp
C. flange
O-ring
340x241800-05403
340X241800-05403
L-280-345
340X241800-05403
O-RING DIMENSIONS
Art. No
d3 x d4
240.67x7 291.47 x 7
Page 5
Page 6
Pressure drop indicator
ELECTRICAL DATA
Breaking capacity 10 W Item Article № Qty Max. working voltage 250 V Pressure drop indicator ΔP 0.9 bar Brass 1 Min. break down voltage 1000V Support
Max. current rating 0.5 A
1800-06419 Washer
Screw
Steel Steel 2 2 Swiveling
coupling Steel
Contact quantity 3 Electrical
connector
Normally closed C1+C3 6 1800-06275Cable gland standard - 1 Normally open C2+C3 ** According to filter model
Common C3
Cross sectional area of the wire:
1.34 mm2 for 2mm dia. contact
3.38 mm2 for 3mm dia. contact
RATING CABLE GLAND
Max. pressure 50 bar Standard : For cable from 5.5 to 9mm dia. Max. temperature 160°C
Dimensions in mm where not otherwise stated. REF. 1/X-EL5-06 Rev: C
Page 7
范文二:船用分油机
第二节 分油机
船舶柴油机所用的燃油在使用前必须经过净化处理,除去其中的 水分和杂质。 而柴油机系统润滑油在使用过程中应循环净化, 除去其 润滑过程中产生和进入的各种杂质。 油料净化中的核心环节是离心分 离,离心分离的最主要设备是离心式分油机
一、分油机的工作原理
分油机分离筒简图 1-立轴; 2-分离筒本体; 3-分离盘; 4-分离筒盖; 5-进油管; 6-出油管; 7-出水管 8-分杂盘; 9-重力环(比重环) ; 10-盘架(有孔) ; 11-排渣孔; 12-分离盘上盖; 13-油水分界面; 14-盘架(无孔) ; 15-滑动底盘 ;16-排水向心泵; 17-排油向心泵
1
2 15
10
14
7
6 5 (a )
(b )
1、分杂机分离原理
)
/(4. 17622s m r
R d v r ?????=
ωρ
(6-1)
式中:△ ρ―― 杂质与纯油的密度差, kg/m3
;
d 一一杂质的直径, m ; ω一一分离盘的旋转角速度,
rad/s;
R 一一 分离盘的半径, m ; r 一一燃油的动力粘度, Pa/s。
2、分水机的分离原理及排出方法
目前分油机油水分界面的位置由 两种方式控制。 一种是由被称做 “ 重力
盘 ”(比重环 ) 的内径来确定的:
E
D D D D 2
12323
2
--
= (6-2) 式中 : D 1 一一出油口直径,固 定不变, mm ;
D 2 一一出水口直径 (重力盘的 内径) ,可以选择, mm ;
D 3 一一油 、 水分界面的直
径, mm ;
E 一一在某分离温度时油、水密度的比值。
Y
分水机工作原理
另一种分油机的比重环被分杂盘 8代替,
另外,两种分油机 (有比重环和无比重环 ) 被分离出并聚集在分离 筒外围的水分, 在排渣期间, 随着分油机的排渣操作筒杂质一同被排 出分离筒。
净油出
3. 离心式分油机排渣方式
(1) 全部排渣式分油机。
此种排渣的持续时间较长, 也就是在排渣期间排渣孔被打开的持 续时间较长,分离筒内存留的所有物质(杂质、油、水)将完全由排 渣孔全部排出。其排渣操作流程循环如图 6-9所示:其中各环节操作 如下:
分油机全部排杂操作流程图
DZY -50分离筒和配水系统
1-复位弹簧; 2-塑料堵头; 3-导水套; 4-分离筒本体; 6-滑动底盘; 6-无孔分离盘 (分杂用 ) ; 7 -主锁紧环 ; 8-分离筒盖; 9-颈 盖; 10-挡圈 (分杂用 ) ; 11-小锁紧环; 12-比重环; 13-盘架; 14-弹簧座; 16-分流圈; 16-固紧螺母; 17-配水盘; 18-分离筒轴; 19-导水座 ; 20-内接管 ; 21-外接管 ; 22-控制阀 ; 23-有孔分离盘 ; 24-滑动圈 ; 26-导水销。
(2
)部分排渣式分油机。
分油机部分排杂操作流程图
R 1 R 2
无环分油机结构图
1. 进口管; 2. 配油器; 3. 滑动底盘; 4. 分离筒本体; 5. 排渣口 (12个 ) ; 6. 锁紧圈; 7. 分离筒上盖; 8. 集渣空间; 9. 分离盘组; 10. 向心泵; 11. 泄水孔 (3个 ) ; 12. 滑动圈; 13. 泄水喷嘴; 14. 定量环; 15. 弹簧座; 16. 配水室; 17. 配水盘; 18. 开启水; 19. 密封水。
(3)排渣控制方法
自动排渣式分油机有两种排渣控制方式:定时式自动排渣和触发 式自动排渣。
①定时式自动排渣是分油机常用的一种排渣控制方法, 。
②触发式自动排渣分油机是在定时式自动排渣基础上发展起来 的。
排渣触发操作
二、分油机的运行管理
1. 加热温度和分油量的确定
不同油料加热温度范围及最大分油量
2. 选择最佳的工作方式
分油机在船上工作时,工作方式有三种:
单机工作:用一台分水机处理全部流量。
并联工作:两台分水机并联工作,各处理总流量的 50%。
串联工作:两台分油机串联,前一台为分水机,后一台为分杂机, 每台都要处理全部流量。 这种方式效果最好, 即使分水机油水分界面 太靠内,分离效果差些,因后级还有分杂机,仍能保持较好的分杂效 果。
3. 操作要点
目前,全自动分油机在船舶上得到了越来越广泛的应用。现以 α-LA V AL WHPX 型分油机为例来说明全自动分油机分油作业时的操 作管理要点。这种分油机除配有一个 EPC400控制单元,一些控制和 检测辅助元件、 分油机马达起动箱外, 还配有供油泵和加热器等辅助 设备,它们共同构成一个净化系统。
1) 起动前的检查
2) 起动和运转
3) 排渣
4) 停止分油机运转
4、分油机常见故障
(1)分离筒达不到规定转速
(2)不能进油或分油过程断油
(3)出水口跑油
(4)排渣口跑油
(5)不能排渣
(6)出现异常振动或噪声
范文三:船用分油机研究
船用分油机研究
Analysis of the Alfa Laval 610 oil
Separators
摘 要
本文首先介绍介了船用分油机的特点、工作原理以及在日常工作中的保养和维修,并且着重论述了船用分油机的自动控制原理和自动控制的实现过程。然后介绍分油机的常见故障及故障排查的一般方法,最后介绍了船舶上使用的船用分油机的基本情况,并且利用所学知识对我船分油机的一个故障实例进行分析,通过分析提出了解决故障的方法,为船舶分油机的维护保养提供了参考和借鉴。
关键词:分油机,特点,维护保养,故障分析
摘要
Abstract
Firstly this paper introduces the characters and working principals of the Alfa Laval 610 oil separation system,describes the daily maintenances of the Alfa Laval 610 oil separator and then it introduces the auto –control system’s basic principals and its practical use in the real ship. Further more, this paper sets out to illustrate the common malfunctions of the separator in the ship and the general methods of solving the problems, finally this paper gives the detailed information about the Alfa Laval FOPX610 oil separators in ship, and it manages to solve the real problems in the separator by our knowledge learned from the school. By doing this paper, it give some suggestions on the maintenances of our oil separator.
Key words: Oil Separator, Characters, Maintenance, Malfunction analysis
Abstract
第一章 引言
随着船舶工业和航运业的迅速发展,分油机越来越广泛地应用于现代船舶上。分油机用来分离润滑油中的水分和机械杂质,以达到减少机械故障,提高机械设备使用效率,并延长机器使用
[1]寿命的目的。分油机是船舶滑油工作系统中必需的专用设备。作为船舶滑油系统中的关键设备,分油机运行状况的好坏直接影响滑油的品质,进而影响船舶动力系统的运行工况,在某些特殊情况下甚至会影响到船舶的航行安全。因此,要求轮机管理人员掌握分油机的工作机理和控制过程,娴熟地对分油机进行操作和故障诊断,确保分油机安全有效地运行,尽量减少故障的发生。现代科技的发展和石油的广泛应用,分油机越来越广泛地应用于现代工程领域的各个方面。尤其是在船舶上,分油机用来分离出燃油和润滑油(包括轻柴油、重柴油、燃料油)中的水分和机械杂质,已达到到减少机械故障,提高机械设备使用效率,并延长机器使用寿命的目的,是船舶燃油和滑油工作系统中必需的专用设备。分油机总是伴随着柴油机的工作而工作。船舶分油机系统通常包括燃油分油机、柴油分油机和滑油分油机,它们分别负责对主机和发电机等燃烧用油和润滑用油进行分离净化处理。是船舶正常航行不可或缺的重要设备之一。作为船舶机舱燃油,滑油系统中的关键设备,分油机运行状况的好坏直接影响燃油、滑油的品质,进而影响船舶动力系统的运行工况。
Alfa Laval FOPX系列自动排渣分油机因其工作可靠,易掌握性而在船舶上得到广泛应用,也深受管理人员欢迎。当然,分油机在运行过程中,难免出现故障,分油机的管理工作主要是通过故障现象,来推断产生故障的原因,确定故障确切部位,进而采取针对性养护措施。现以Alfa Laval 船用分油机遇到的跑油故障作分析,解决因EPC-41控制单元“自矫正功能”引起的排渣程序中的跑油现象。EPC400作为控制单元应用于MMPX、FOPX、MOPX系列分油机中,希望此机型
[2]用户注意根据实际情况调整系统的一些参数,以使得分油机在正常状态下运行。
第一章 引言
第二章 船用分油机特点介绍
2.1主要特点
船用为部分排渣分油机,该分油机的特点是燃油可以连续的供给分油机,在出水口安装由微机控制的放水电磁阀,供油换向三通阀在分油机启动、故障和停止时将燃油导回沉淀柜,而在正常的运行中始终处于分油机供油状态。每次排渣其排渣口只打开很短时间,排出量是分离片外缘和壳体之间容积的百分之七十。分油机取消了比重环,而是多了流量控制盘,不使用比重环是为了适应所处理的油料比重在不断增加的要求。在控制方面,控制器不再是简单而固定的时序控制,而是以净油中水分含量为主要目标的具有可变程序的时序---程序控制过程。该控制系统还具有自诊断功能,如果出现问题会给工作人员提供足够的提示。该分油机的工作状态由EPC400
[3]控制单元来控制,附加WT200型水份传感器来监控分油机的分油效果。
2.2自动化控制简介
EPC400控制单元是FOPX型分油机控制系统中的一个重要组成部分,它的主要作用是是用于监控分油机的处理过程。它控制分油机的启动、分油、排渣和停止时序。它是通过从传感器来的信号监视整个过程,在实际参数超过范围时发出报警。该控制单元可以对不同的工况编程,编程是通过设定一些诸如分油机类型、时间、时间极限等参数来实现的。一些参数在安装时已经设定好了,但在处理的过程中可以非常简单的进行调节。该控制单元同时还具有一个比例积分调节器来控制Alfa Laval的电器、蒸汽或者其他带有控制阀的加热器。EPC400控制单元的报警功能设计是用来保证分油系统始终处在安全状态。该单元有两种不同的报警功能,与传感器有关的报警功能在EPC400控制单元的面板上由发光二级管模拟显示;与显示窗有关的报警功能在EPC400控
第二章FOPX610型分油机特点介绍
制单元的显示窗显示警报代码,报警时,显示窗左边闪耀,右边常亮。若是同时出两个以上的报警,EPC400控制单元将按警报的优先顺序来显示。WT200水分传感器的主要做用是探测分油机排油中水分的含量,然后将其转换为电信号传送给EPC400控制单元, EPC400控制单元将这一数值和预先设定的触发数值相比较,再决定分油机的动作。
由于分油机所分油品中含有的水分不同,EPC400控制单元的控制过程就有所不同。例如油中无水分、中等水分、高水分和极高水分,控制单元对分油机的自动控制过程就有所不同。
油中无水时分油机工作循环
(1)补充水加入分离筒,其作用主要时用来软化油渣,以达到良好的排渣效果;(2)控制单元存入一个参考值;(3)当最大的排渣时间间隔过去之后,加入置换水,用来减少排渣时的燃油损失;(4)在正常的分离过程中,油水分界面逐渐向里移动,但是还达不到分离盘的边缘,所以没有水分和净油一起排出分油机;(5)当油水分界面达到分离盘边缘时,水分传感器就可以检测到净油中存在的轻微的水分变化,一旦达到触发值,即可排渣。以后又加入补充水,存入一个新的参考值为起点,开始另一个工作循环。
中等水分分油机工作循环
(1)排渣后加入补充水;(2)存入一个新的参考值;(3)在两个最大排渣器来监控分油机的分油效果。
图2-1 FOPX610 型分油机工作原理图
FOPX610 型分油机的分油原理(如图2-1所示),待分油从201口连续进分油机,经分配油锥体进入每个分离片,由于水分和杂质的比重比油大,在强大的离心力的作用下,水分和渣质在离心力的作用下被分油机甩向分离盘的外侧,聚集在油渣间12中,分离后的净油被推向分离盘的内侧。分离出来的油被向心油泵4从净油出口220排到日用柜,而分离出来的水被向心水泵2从
第二章FOPX610型分油机特点介绍
排水管221排到油渣柜。
在排水管221上装有一个排水电磁阀,在净油出口220上装有一台WT200型水分传感器,它能精确的检测分油机所排的净油中的水分含量。经过分油机分离过的净油中基本不含水分或水分很少,但随着分离过程的进行,当油水分界面移动到分离盘外侧边缘时,就会有少量的水和净油一起逃逸,WT200水分传感器会准确的探测到净油中水分的含量,这个数值被送到EPC400控制单元和预先设定的数值进行比较,然后由该装置决定分油机的动作。当待分油中水分含量较少时,分油机在排渣时为了减少排油损失,分油机会从置换水进口206进置换水,以使油水分界面内移,从而达到在排渣时减少排油损失的目的。
FOPX610分油机开始正常分油时(如图2-2所示),分油机打开密封水阀MV16,密封和补偿水进口376开始进水,密封水经过配水盘进入滑动底盘6下方的密封水腔12,此时由于在弹簧的作用下,滑动圈2将泄水通道9关闭,密封水腔形成封闭状态。在分离筒高速运转的情况下,滑动底盘下方的压力大于上方的压力,从而使滑动底盘上移压在分离筒盖上,此时排渣口1被关闭,使分离筒密封以进行分油作业。为了补偿密封水由于少量泄漏造成的损失,由密封水管376继续进补偿水。
当分油机排渣时,开启水阀MV15开启,开启水进口372开始进水,高压的开启水进入滑动圈2上方的开启腔室11,开启水的压力足以克服弹簧7的张力,把滑动圈压下,泄水通道9被打开,密封水通过泄水孔3流出,这样滑动底盘6上部的压力就大于外下的压力,滑动底盘下落,分离筒内大部分油渣和水通过排渣孔1排出。当滑动圈2和定量环5之间的密封腔室12充满水时,腔室11、12,即滑动圈2上下压力相等。在弹簧7压力作用下,滑动圈2上移关闭泄水通道10。大量水经垂直孔进入滑动底盘6的下部空间,再次把滑动底盘托起,开始下一个工作循环。
在分油机到整个排渣过程中,开启水阀MV15进水时间设定值是3秒,而滑动底盘下落下落的时间是0.1秒,在此时间之内分油机油渣间70%的水和油渣从排渣口排出。由于分油机每次排渣的量只是其油渣空间容量的一部分,因此分油机不必切断进油就可以排渣。
第二章FOPX610型分油机特点介绍
图2-2 FOPX610 型分油机分离筒、控制水路示意图
第三章 FOPX610分油机的基本操作要求 3.1 FOPX610分油机的开启
1)检查分油机的电源是否正常,涡轮室的油位是否正常,离合器是否松开,进出油管路的阀是否处于正常的位置。
2)若以上都正常,启动分油机燃油供给泵,将蒸气加热阀打开,将温度控制器调到98摄氏度。注意,调节进油温度时要慢慢的调,不能一下就调到98摄氏度。
3)待温度达到要求以后,启动分油机,等分油机的转速达到要求以后,按下EPC400控制单元的进油按钮,给分油机供油。
4)观察分油机供油以后工作是否正常,有无异常的震动或是噪音。通过EPC400上的显示数
第三章FOPX610型分油机的基本操作要求
据,来判断分油机的状态,如果一切都正常,说明分油机开始正常的工作。
[5]5)等分油机完全停止以后,合上分油机的刹车器 。
3.2分油机的分油排渣操作及运行管理
一、分油机的分油操作
(1) 分水机
1) 分离筒通入工作水封住排渣口。
2) 分离筒上部引水建立水封,当出水口出水说明水封完成,关闭引水阀。
3) 先开分油机出油阀,知道达到需要的分油量,然后使进油阀开度固定。
4) 适当调整加热温度,使之达到规定值。
(2) 分杂机
当使用分杂机时,在密封好分离筒后,进油阀应迅速开至要求流量(因为不存在水封被破坏的问题)。
二、分油机的排渣操作
(1) 先旁通进油阀,缓开引水阀将分离筒中剩的油赶走。
(2) 若出水口出水,立即关闭引水阀把控制阀转至开启位置,稍停3-5秒后,当听到冲击声,说明污渣已经排出。
(3) 工作中排渣间隔时间取决于油的杂质含量,最长不得超过四个小时。 三、分油机的运行管理
(1) 检查分油机是否有异常振动和噪音。
(2) 检查分油机齿轮箱油位。
(3) 检查随机泵是否有发热现象。
(4) 检查有关油水箱柜的液位是否正常。
(5) 检查分离油的流量和温度。
(6) 检查排渣口和出水口(分杂机无此出口)是否有跑油现像。 3.3 FOPX610分油机的停止
1)首先,先将分油机手动排渣,以防止下次分油启动时由于油渣的粘连无法启动。从控制单元开始自动进行一次排渣。
2)手动排渣后,按下EPC400控制单元上的分油机停止分油的按钮,分油机会自动按照程序排渣一次,然后分油机才开始停止分油。
3)手动停掉分油机进油的蒸气加热阀,同时将温度调节指针调到适当位置。
4)一段时间以后,当EPC400控制单元显示分油机的工作状态为OFF时,手动停止分油机燃油供给泵。
第三章FOPX610型分油机的基本操作要求
3.4使用中的注意事项
开启分油机前要将分油机的刹车器松开,启动后看旋转的方向是否正确,正确方向是顺时针。检查有无异常的振动,在启动之初当分油机通过临界转速时会有振动,这都属于正常现象,在使用中要逐渐了解振动的表现和规律。如果分油机在正常的工作中有异常的振动,那么就要立即停止分油机。并查找分油机震动的原因,在未找到故障的原因之前不能开启分油机。若是开启,因为分油机内部的高速旋转,严重时会造成分油机部件的损坏甚至伤人。一般情况下震动都是因为分油机内部脏污或是在分油机安装不当导致不平衡所引起的。在分油机刚启动时,启动电流会比分油机正常工作时的电流大很多,但是随着分油机转速大升高分油机的电流会逐渐的降低并维持在一个稳定的数值上。如果分油机的工作电流维持在较高的数值上不变,这说明分油机跑油,这种情况必要时要停止分油机进行检查。分油机正常工作以后要检查供油流量是否正常,调节出口压力为2.0br。如果要使分油机停止工作,最好是手动的对分油机进行排渣一到两次,因为分油机排渣孔会有一些积累的油渣,若不排出去,由于油渣的粘连,下次启动有可能使分油机马达负荷过大,无法启动分油机。在没有完全停止之前不能进行分解工作,因为其内部高速旋转时会有伤人的危险。
在对分油机的日常使用和巡班检查时,主要是检查分油机有无异常噪音,异常震动,螺栓有无松动,进出油管的连接是否有松动,有无漏油,涡轮室滑油液位是否正常等
第四章 FOPX610 分油机的例行保养及维护 4.1周期性维护保养的基本要求
分油机油底壳的滑油要根据说明书的要求及时的更换。根据说明书的要求,FOPX610分油机涡轮室所使用的滑油型号是SP68,滑油更换的周期为1000至1500小时,或者至少每年一次,如果运行时间少于1000至1500小时且使用的是DOIL那么更换滑油的周期可以延长至2000小时。分油机的例行保养有三种,即IS(INTERMEDIATE SERVICE)、MS(MAJOR SERVICE)和3S(3YEAR SERVICE)。IS检查包括维修检查主要是进出油和分离设备,每3个月或2000小时进行一次,分
[13]离筒内的密封垫片和O-RING要全部换新。 MS主要包括停机修理和问题修理,每12个月进行一次,密封垫片、O-RING轴承换新。 3S的内容不仅包括IS和MS的内容,同时分油机的框架和
第四章FOPX610型分油机的例行维护及保养
底脚也要换新。
4.2解体和组装的基本要求
在分油机的日常工作中,一般每三个月要对分油机进行一次例行保养和内部清洁。在拆分油机之前要仔细的阅读说明书,同时将所需要的普通工具和专用工具准备妥当。在拆分油机的过程中要小心,不要因为粗心大意而导致分油机内部的部件损坏,拆下来的分油机部件要小心的放在垫板上,一些小的部件要专门找一个盛放工具装起来,以免丢失。然后再将拆下来的部件按说明书的要求做清洁和处理。
在组装分油机时,要注意分油机内的一些部件为反牙,如大锁紧圈、小锁紧圈、锁紧螺帽等,这些都是逆时针为上紧,安装的时候一定不能搞错方向。在组装时要注意部件和部件之间的位置要安放正确,例如有些部件上有标记,在组装的时候标记和标记要对齐。在锁紧大锁紧圈的时候要注意力量要合适,上紧到大锁紧圈上到标记和分离本体上的标记对齐就好,不能超过,也不能不及。把外压紧盖放在正确位置且拧紧装好连接室,装好水泵,油泵连接出水管,在进油管加上顶塞,拧紧。
4.3清洁时的基本要求
分油机内部清洁时一般都有专用的的化学药品,当用化学药剂对分油机进行清洁时,要熟读化学药品使用说明,做到对其性能和注意事项有充分的理解。对于分离盘内部的清洗,采用化学药品可以在不损坏分离盘本体的情况下,有效的除去油污。在清洁分离盘时,把分离片放入DC(DISC CLEANER)浸泡半小时以上,然后取出来用淡水冲洗,最后在放入煤油中清洁干净。在清洁分离片时要注意不要划伤分离片的表面,更不能使分离片变形。化学药品DC对皮肤具有腐蚀性,在工作时要注意安全,若是粘到皮肤要及时的用大量清水冲洗。其他部件的清洁可以使用煤油和软刷,清洁时要注意保护部件的表面不被划伤。因为分油机的马达没有防水的功能,所以分油机外部清洁不可以用水直接冲洗,这样会对马达造成损坏。冲洗水容易透过金属缝隙,进入电线绕组。
在清洁时要注意检查分油机部件的腐蚀及裂痕。如果部件的表面有腐蚀或裂痕,应该仔细的比照说明书的要求。若是还可以继续使用,应对部件表面做非常细致的处理,同时在使用的过程中也要对分油机格外关注。若是腐蚀或裂痕过大,不能继续使用的要更换备件,如果没有备件,而且情况紧急应和制造商联系确定使用方案。同时Alfa laval拥有独到的CIP (CLEANING IN
PLACE) 系统,该系统可以在不用解体的情况下可以对分油机进行内部对清洁。 4.4更换滑油的步骤和要求
分油机更换滑油时,可以通过分油机涡轮室下方的放残孔来放油,去掉放残孔的塞子,将原来的滑油放出。若是有必要,可打开端盖用干净的布彻底的清洁涡轮室内部,然后再向涡轮室加新油,油位应处与液镜的中间位置。在分油机正常工作的时候,油位应该在镜面的1/3处,如果
第四章FOPX610型分油机的例行维护及保养
油位没过了涡轮,就会导致温度过高同时还有振动产生,如果加完滑油后发现分油机噪音过大或
[4]有振动则表明运行不正常应该停机检查 。
第五章FOPX610分油机的常见故障及处理方法
原因 正确处理方法
油量供应不足 检查供油泵供油,调节供油的流量
供油泵滤器堵塞 清洁滤器
进油三通阀处于循环位置 检查三通阀空气供给,检查三通阀的好坏
进油加热温度不足 调节进油温度
背压过低 调节背压阀,增加出油背压
工作过程中分离筒开启过于猛烈 检查开启水阀是否漏泄
分离筒漏泄 查看操作说明书
第五章FOPX610型分油机的常见故障及处理方法
排渣失败
原因 正确处理方法
开启水供应不足或没有 检查供水系统,应不小于18L/min 开启水阀MV15故障 检查MV15阀等工作状况 工作水系统故障 通过手动打开MV15阀排渣;解体并检查工
作水系统
定量环安装不当 将分油机解体,重新安装定量环 其他原因等 根据具体的情况,查看相关说明书
分油机转速低
原因 正确处理方法
剎车没有释放 松开剎车
连轴节坏或充满油液 更换或清洁磨擦片 分离筒有泄漏 拆开分离筒检查
马达故障 修理马达
轴承损坏 更换新轴承
水分传感器故障
原因 处理方法
电路连接断掉 检查电路连接 水分传感器内部脏污 用煤油清洁水分传感器内部 水分传感器电路板故障 检查水分传感器电路板,必要时换
新的电路板
分油机振动
原因 正确处理方法
振动调节器减震器橡胶损坏 更换橡胶减震器
轴承损坏或过度磨损 更换轴承
不对称的油渣沉积在排渣空间 拆解和清洁分离筒 分离筒轴弯曲(最大0.04mm) 更换新的分离筒轴 分离筒失去平衡,清洁不彻底, 拆解分油机,并清洁和检查后正确 装配不正确,分离盘压力不当 组装
油泵的安装高度或分离筒的轴心 光滑滑动底盘的边缘或换新 高度调节不正确
油位太低 检查油位有必要可以更换新油
如果分油机因故障报警,那么在分油机的EPC400控制单元上,相应的警报指示灯就会发出
第五章FOPX610型分油机的常见故障及处理方法
[6]红光,并不停的闪烁,机舱内同时伴有警报的汽笛声。首先,先要确认警报,按下警报确认按钮,把汽笛和报警灯停掉。然后根据分油机的警报去查找原因,等把故障排除以后,再按一下警报确认按钮。若是故障已经解除,则分油机就可以接着正常的工作。分油机的警报有很多种,而每一个警报的原因有很多,因此解决分油机报警的时候一定要细心观察,通过警报和分油机故障时的外在表现来判断故障的原因。根据判断在进一步去把故障解决掉。例如排渣失败可能原因是没有工作水或工作水很少,也可能是开启水阀MV15问题。首先就需要检查供水系统,如果可以确定工作水系统没有问题,那么问题就可能时候分油机内部的机械故障。因为就一般情况来说,分油机的故障也就无非是控制系统和机械故障两个部分。其中机械故障一般都是由于分油机长期的工作,没有及时的保养,以致内部脏污,从而导致了机械的故障。通过合理的推断,既可以减
[7]少工作量,又有利于解决问题 。
5.1出水口跑油
出水口跑油是分油机最常见的故障,原因很多,主要有:转速不够; 比重盘内口径不当; 进油量过大; 分离筒内积聚污物太多,分离盘片脏堵; 配水盘故障,水封建立不起来;加热不够,进口油温太低; 高置水箱水位过低导致托盘没有托起等等。
虽然原因很多,但大多是由排渣口脏堵引起的,只需将分油机进油阀关闭,手动排渣一到两次,故障多能排除。其它原因,如分油机出油阀没有打开或没有全部打开引起跑油,不属于机械故障,就不再讨论了。按故障表逐一排查,不仅费时费力,而且可能使问题复杂化甚至根本找不到毛病。不妨采用这样的思考方式加以分析,例如:上午分油机正常,下午就跑油了,显然可以排除比重盘内径太小; 若进油量太大,只需将进油阀关小一点(注意,这时要手动排渣一次,否则,跑油现象未必会停止)。 至于是不是分离筒内污物太多,可以查看轮机日志,看是不是到该拆洗分油机的时间了。根据师傅们的经验,自动排渣式分油机一般一到二个月洗一次就可以了;但若是重油太脏,则应增加排渣次数(调小排渣间隔时间,含渣量低于0.3,的重油,每分离1000升排渣一次)。
配水盘故障,一般是橡皮圈老化,弹性不足,密封性降低所致,应该按照橡皮圈的寿命定期更换;另一种可能是工作水不干净,配水盘脏赌,应该清洗配水盘,更换橡皮圈。至于“进口油温太低”和“高置水箱水位过低”等原因,目测就能确定。
经上面分析可知,尽管一件事物纷繁复杂,经过条理的分析,就会变得简单清晰。这种思考方法很重要,可以运用到其它各项工作中去。 5.2排渣口跑油
发生排渣口漏油(下漏油)是由于排渣口未能封闭,或滑动底盘与排渣胶圈密封不良导致。 具体来讲有以下几种原因:
1)操作水压力不足
软水系统恒压装置的压缩空气泄露而没有及时补充,水系统关闭时压力正常,但开阀后压力不足,操作水管路泄流、脏堵或滤网堵塞,使操作水压力不足而导致滑动活塞下方的关闭水量不
第五章FOPX610型分油机的常见故障及处理方法
[8]足。处理措施是充加压缩空气和清洗水路滤网 。
2)操作水电磁阀失灵或复位不良
操作水电磁阀一直处于进水排渣状态,致使滑动底盘下移处于常开位置,发生从排渣口漏油现象。 处理措施是修理或清洗操作水电磁阀。
3)滑动圈不能上移堵死密封水腔泄水口
分离筒上的小孔M堵死,不能泄水;滑动圈下方弹簧失效;滑动圈上方塑料堵头失严。 4)滑动底盘与分离筒盖不能贴紧
[9] 滑动底盘上端面密封环失效;传动齿轮和轴承过度磨损使立轴下沉 。 5.3 船用分油机的故障实例分析
某船舶有两台燃油分油机,互为备用也可以同时投入使用,但一般在日常的工作中只使用一台。No.1分油机有一天在使用的过程中发现排渣口跑油。其主要表现是分油机低压报警,当把
[10]警报消掉以后,重新启动分油机发现分油机的电流一直维持在较高的数值上。凭以往的经验判断应该是分油机跑油了。将分油机复位后,进入下一个分油过程。发现有水封水进入分油机,但是分油机排水管看不到有水封水流出,很明显分油机没有密封。当延长密封水供给时间又可以密封且正常工作,但是几天以后就就完全无法密封了,即使从排水管玻璃镜中也看不到有水封水流出。
很显然在分油机无法密封的情况下,所进的水封水直接泄至了油渣柜中,根本就无法建立水封,这就是为什么看到水封水进入了分油机,但是排水管看不到水封水流出的原因。理所当然,所进的油从排渣口被高速旋转的分离筒甩到了油渣柜中(排渣管与油渣柜是密闭连接,而且煤油观察孔,这一点是无法用肉眼直接看到的)。这就是为什么油泵有压力,进油三通阀工作正常,一旦分油机发生低压报警,分油机出油管没有压力指示的原因。接下来的工作就是找出为什么分油机不能密封的原因,为此通过拆下密封水和开启水的进水控制内外短管(此短管油软管与相应的电磁阀相连),手动开启密封水电磁阀,检查确认密封水畅通无阻,这说明问题多半出在配水机构。分油机不能密封,说明活动底盘没有被抬起,或者抬起了却不能使其上部的盘盖密封。在此故障中,通过上述分析查找确认有足够的密封水进入配水装置中,无法密封的原因有很多种,如转速不足、滑动底盘下部弹簧座O-RING 老化漏水、配水盘小孔堵塞、滑动底盘上的堵头密封不良以及滑动底盘上的矩形尼氟龙密封圈的密封不良等都可能使滑动底盘并不能抬起或是与上盖密封不良。所有这些可能原因都只能通过拆解分油机检查配水机构才能查明。吊出后一一的做了细致的检查,发现分离本体的密封水进水小孔被水中的杂质堵塞。到此故障的原因终于真相大白,在故障的前期小孔被部分堵塞,通过手动增加进水还可以密封,因为水质不好小孔被完全堵塞,所以造成分油机最后完全不能密封。清洁了相关的进、出水小孔,检查O-RING发现弹性尚可,并且凸出自己的环槽有一定的高度,故不需要更换备件,装回后使用,故障排除。
在这次故障以后,机舱同仁总结了这次经历和应该注意的地方,机舱部领导加强了对分油机重力水柜对清洁和保养力度,还将分油机各个控制水路的滤器拆下来检查,不行的进行了换新,同时嘱咐三管加强对滤器清洁对频率,此后同类故障在也没有过。在这次故障中我觉得解决问题不要急于求成,头脑思维一定要清晰明确,一步一步的分析,找明大致方向再逐个的分析排除,
大连海洋大学本科毕业论文(设计) 第五章FOPX610型分油机的常见故障及处理方法 直到找到真正的原因才着手解决,这样就免去了许多的无用步骤。现场分析问题,贵在思路清晰。
结论
这次论文学习中,更加体会到学校理论学习的重要性,更加体会到理论学习在实际应用的重要性。在这段时间的学习中,通过向通过自己的学习和老师的指导对分油机的管理和维修,使我对分油机无论是结构还是故障的认识都有了一个质的飞跃。通过在日常的工作中对分油机结构和性能的不断了解,在故障的处理方面我都逐渐有了自己的见解。
分油机的发展越来越朝着自动化与精密化发展,由于分油机对减少船舶运营成本起着决定性的作用,因此分油机的转速也越来越高,分油机转速是否足够至关重要。首先转速的高低直接影响分离的效果。分油机本身并无转速表,但马达电流就是转速的直接反映。分离盘片脏、分油机是否密封、部件安装是否正确、立轴是否过度磨损等,都是通过马达电流反映出来。因此分油机
结论
的发展与先进性越来越受到重视。
致谢
致谢
参考文献
[1] 黄少竹,船舶柴油机,大连海事大学出版社,2006年
[2] 吴恒,船舶动力装置技术管理,大连海事大学出版社,1999年 [3] 郑凤阁 ,轮机自动化,大连海事大学出版社,2006年 [4] 刘传华,船用分油机的预防性保养,2006年
[5] 刘传华,水运科技信息,1999年第3期
[6] 张慧芳,如何快速排除分油机故障,2000年第3期
[7] 张慧芳,航海技术,2000年第3期
[8] 黄少竹,主编.现代船舶柴油机故障分析,大连海事大学出版社,2006 [9] 汪木松,机舱管理[M] ,武汉造船工程学会,1983 [10] Alfa Laval. marine & power , FOPX610 separation system , Alfa Laval 2001年
[11] English of marine engineering ,大连海事大学出版社,1999年
参考文献
[12] English of marine engineering ,大连海事大学出版社,1992年
[13] Matthias amuser Insights into piston-running behavior, 2001(02) 年
范文四:船用分油机
船用分油机
1 KYDH204SD-23 型号
2 265mm 转鼓内径
3 转鼓转速 约8086转/分
4 计数器转速 120转/分
5 9703 分离因素
6 额定处理量 ?2000升/时
7 电机型号 Y112M-4 Β5
8 4KW 功率
9 外形尺寸,长x宽x高, 810x968x1139, mm, 10 580Kg 质量
启动前 1,检查齿轮箱润滑油油位是否足够
2,油料密度,比重环
3松开刹车,用顺时针方向拨动转鼓,转动灵活无异常
1, 分油前检查重沉淀柜加温是否在40?以上,提前5~10分钟开启分油机加温阀。. 2, 检查齿轮箱的油位。
3, 检查分油机摩擦筒的刹车是否脱离状态。
4, 检查沉淀柜出口阀是否开启,检查各阀件的开关是否在正常位置。 5, 启动分油机,待转速达到正常120转/分或者等电流降到额定数值,5分钟左右,。 6, 将旋转控制阀转到位置3,关闭,,直到指示器管子水溢出。
7, 将旋转控制阀转到位置4,分离,。
8, 打开水封水进水阀,直到重相,玻璃透视窗,出水口出水为止,关闭此阀。 9, 开启分油机,开启污油泵进出口阀,启动污油泵,根据需要调节相应阀的开度,控制
分离量。,压力在0.3Mpa,,
10, 排渣,关闭油泵和进出口阀,加水封水出水孔有油流出,压力表有压力,把水封水开
到最大,打到排渣。,排渣时间:一般是分离2小时排一次渣,可根据油的
, 含渣量适当增减排渣的间隔时间。
注意:关闭分油机记得关闭沉淀柜出口阀
停止污油泵,关闭污油泵的进出口阀,开启水封水赶走分油机内的燃油,
直到重相,玻璃透视窗,出水口出水为止,关闭此阀。将旋转控制阀转到
位置1,排渣,;排过一次渣之后,再按6~8步骤操作后,排渣时同时观察排渣口污水的清洁程度,决定是否还需要多排几次。
注:若怀疑活塞环密封不好,可在排过渣之后,一人稍开水封水进水阀,一人观察排渣口是否有水流出。
范文五:Purifiers+and+BW+separators船用分油机
Operation of a Centrifugal oil purifers
Preamble
The following description relies on the reader having an understanding of the function and internal design of a modern self cleaning centrifugal purifer.
The method describes the operation of a manually controlled system. It is accepted that the vast majority of units are automated, it is intended allow better understanding of the automated process by doing this. The
The unit described is a sliding bowl type, does not have on line sludging capability with light phase requiring heating. Operating water is required for both opening, and closing the bowl. It is accepted that in common designs only opening water is supplied, once supplied this water leaks out until it reaches a level determined by a weir arrangement. The water remaining beyond this weir acts to close the bowl Operating, displacement, seal and sludging water are delivered in finite quantities governed by the type and size of bowl, and the supply water pressure. Although not mentioned it should be taken for granted that water introduced is of a set quantity
Starting and stopping
Before starting the purifier the correct sized gravity ring must be in place for the light phase specific gravity at required delivery temperature.
Most units have a brake arrangement fitted acting on the bowl to slow during stopping. This should be check to be disengaged.
The use of this brake is determined by manufacturers recommendations. The brake should be seen as an emergency device to slow the bowl in the event of some problem, typically an out of balance of the bowl caused by sludge not being evenly removed from the bowl.
Where no preference is given it is the authors recommendation that the brake be used. The reason for this is to allow the bowl to pass as quickly as possible through any critical vibration harmonics.
Correct operating and sludging water supply pressure should be checked The light phase (oil) supply, discharge valves may be opened, the flow control valve and back pressure valve may be set at approximate initial settings. The three way valve is set to recirc (dump)
Remember that when the oil is introduced to the bowl the bowl is cool and so the oil will be cooled and will tend to pass over with the heavy phase. This action may be reduced by having the back pressure discharge valve slightly more open than required closing as the bowl warms.
The bowl may be started. Drive to the bowl is via a centrifugal clutch arrangement reducing the starting current on the motor. The start up time is determined by the slippage of this clutch which is in turn determined by the number of pads. The oil is now being circulated though the heater. The heating medium may be introduced to bring the oil to purifying temperature
It should be noted that for some designs the motor is non-standard being able to carry high starting currents over a longer period. When requesting replacements this should be noted.
Too few pads causes an overly long start up time. In addition, the drag of the liquid as it leaves the bowl during a sludge cycle causes a reduction in speed. For automated systems, this speed must be regained before the oil is reintroduced otherwise carryover can occur. With some designs correct sludging is determined by an expected rise in drive current caused by the motor trying to bring the bowl back to speed. Too few pads may cause problems in both these cases. Too many pads leads to excessive force on the drive gear leading to premature failure especially of the wheel and the electric motor.
When the bowl has reached it operating speed the bowl may be closed by introducing closing operating water.
this may be checked by viewing the external speed indicator or by observation of a reduction in amps as the bowl reaches its operating speed. The best method is a combination of the two.
Observe the amp reduction and visually check the speed indicator to confirm that a fault has not occurred in the clutch.
Once correct oil temperature is observed the purification process may begin. Seal water is introduced to the bowl. The three way valve is operated to supply oil to the bowl. Correct flow and back pressure should be set once full flow is achieved. The amount of heating medium to the heater should be increased as required
The sludge port should be viewed to ensure no leakage from bowl- remember to close port before sludging. Check heavy phase (water) shute to ensure no oil overflow. Check operating water shute to ensure valves have isolated
It is unlikely that the bowl will immediately come
The amount of carryover may be reduced by opening the back pressure valve. The best solution is to removed the cool oil that is in the bowl by sludging. This may be repeated couple of times before the bowl has reached operating temperature.
The correct function of the desludging mechanism should be checked.
Sludging
?Change three way valve to recirculation (dump). Reduce heating medium to heater if required
?Introduce displacement water. This removes the oil from the bowl preventing wastage
?Open bowl open operating water
?Observe amps ( increase), check sludge port ( see discharge). Close sludge port. There is normally an audible indication that the bowl has opened
?Operate bowl closing water
?Once amps has returned to normal running the bowl can be assumed closed, again there is generally an audible indication of this
?Bring unit back on line
Once the unit has been proved on line and operating correctly the alarms and shutdowns should be tested. Where the units overflow to a sludge tank the correct operation of the alarm should be checked.
The testing of the alarms and shut downs is paramount. Once completed, especially for main engine lube oil purifiers, a note should be made in the engineroom log book
It is common to find dedicated sludge tanks for the purifiers. The level in which is kept artificially high and just off the high level alarm. In this way the tank acts as a back up alarm for the purifier.
Automation
The vast majority of units will be fully automated for UMS enginerooms. Sludging will involve pressing a single button. A controller will then cycle through the operating, displacement and seal water valves as well as operate the three way valve. The heater will have an independent controller although a zero output signal may be generated by the purifier controller during the sludge period.
Detection of correct desludging may be by drive motor current, as discussed, flap arrangement which is struck by the discharge from the open bowl or by measuring the discharge pressure which falls to or below zero pressure during the sludge cycle.
Purifiers and Clarifiers differ only in that clarifiers are not set up to remove water. Their design are similar to the point that most purifiers found on board can be converted to
use as a clarifier with simple alteration of the gravity disc
If an oily water mix is placed into a tank then speration of the two parts will begin with the lighter element rising to the top. The rate the seperation occurs is governed by several factors including the difference in specific gravities and the force of gravity acting upon it.
For mixes placed into a settling tank there is little that can be done about the gravity but the difference in the specific gravities can be increased by heating. This because water density changes at a much reduced rate when compared to oil. The limiting factor to this is that the water cannot be heated above 100'C for obvious reasons. A wide shallow tank will increase the rate of clarification over a tall thin tank Principles of operation
When a volume of light oil is placed into a tank contain a weir and a quantity of water the fluids will tend to arrange themselves as shown above. The height of the water in the weir rises to a point governed by the volume ( and thereby relative height) and specific gravity of the light oil.
Knowing this it is possible to form a rudimentary purification system.
As a oil/water mix is fed into the tank seperation begins with heavy particulates falling to the base of the tank along with water which joins the other water excess overflowing the heavy phase weir. Hopefully clear oil passes over the light phase weir. The problem arises that to ensure their is suffcient time to allow for full(seperation of the oily mix the flow would have to be very small relative to the size of the tank.
Principle of seperation in centrifuge containing angled plate stack
Fluid moving between two plates has a velocity greatest at mid point and minimum approaching the plates.
a particle entering into the plates will tend to be pushed upwards by the fluid flow. All the time centrifugal foce tends to retard the horizontal component of the movement causing the partical to approach the underside of the top disc. As it approaches the fluid flow velocity reduces. The centrifugal force eventually overcomes the force acting on the partical due to fluid movement and th epartical starts to move towards the oute rim. The centrifugal force acting on a particle is proportional to its mass therefore a small particle will tend to move further under the influence of fluid flow. Indeed a particle small enough will be carried through the plates and out with the discharge. In this way it can be seen that reducing the flow rate to a purifier will tend to increase the quality of the output.
Basic centrifuge
The basic centrifuge differs than that described above most obviously by sitting on its side. In reality it takes the form of a round bowl a cross section of which will show something like that seen above. Gravity is replaced by centripetal force as the bowl is spun at high revolutions thereby creating very high g-forces.
A disc stack is incorporated to encourage a laminar flow increaseing improving the seperation effect. Dirty oil is introduced via a centreline oil feed dip tube. The oil is led to distribution holes which are refected in the disc stack but not the dam
The following factors are of importance when understanding the function of the purifier
?Increasing the sg of the oil will tend to push the interface outlet and cause overflow from the heavy phase outlet untill the equilibrium is restored. Should the interface be moved so far as to breach the dam oil will be issued from the heavy phase outlet and an alarm will sound.The ideal position for the interface is to lie over the distribution holes
?Reducing the sg of the oil will tend to bring the interface towards the axis, this reduces the force of speration on the oil mix and reduces the efficacy of the unit possibly leading to contaminants and water carryover with the light phase outlet
?the
?The flow rate of a purifer should be set to optimise removal of whole system impurities. The lower the oil feed the greater the time for impurity removal and the more efficient the purification. The higher the rate the greater the amount of system oil is treated per unit of time. For a system such as main engine oil where contaminants are continuously being added to the system. As a rule of thumb the total volume of the system should pass through the purifer three times every 24 hours, this rate may be vary depending on operational parameters. A similar calculation has to be made with fuel oil to ensure removal of water and sludges which may accummulate over time.
Choosing Gravity Disc
The graph shown above is one typical of one found in a purifer instruction book for selecting appropriate gravity disc size. Shown on the diagram is an example of an oil of sg 0.93 at 0'C. The sg at 15'C for use with this graph is found by projecting along a horizontal line to 15'C. This step would be omitted if the sg at 15'C was already known. A line is then drawn parallel to the pre-drawn sloping lines. Where the drawn sloping line cuts the appropriate oil supply temperature isothermal then This becomes the selection point for the disc. This is found simply by ascertaining which size band the point lies in.
Self cleaning centrifuge
The majority of purifers found on board are of the self cleaning type intat they are able to open the bowl to discharge any accummulated sludge. Apart from the sliding bowl the main difference is the centripetal pump over the simple design. In this
a fixed centrigual style impeller is mounted in the light phase outlet drawing the oil and discharging it at pressure sufficient to deliver it to the receiving tank. A discharge valve is fitted which is adjusted to give a constant back pressure in the bowl. The adjustment
of this back pressure tends to move the position of the interface but more importantly increases the oil in the light phase delivery chamber increaseing the immersion depth of the lip of the pump. This reduces possiblility of air being entrained and removes foaming.. In the event of bowl failure back pressure will fall, this may be detected by a pressure switch initiaing a shut down
Desludge event
For the bowl shown above a typical sequence of events would be< p="" class="">
1. Bowl online
2. sludge cycle timer activates and bowl comes off line (heater may be disconnected at this time
3. Oil feed stopped
4. Oil still in bowl displaced by addition of a quantity of displacement water
5. Bowl open control water passed to bowl via distributor, bowl opens
6. Bowl open water discharged via a small orifice
7. Bowl closes
8. Seal water added
9. Oil feed commenced, timer started to give set time for back pressure to build up for oil disharge
10. h eater reconnected
Typical alarms and shut downs
The following gives a general list of alarms only some of which may be fitted.
?Back Pressure shutdown- this measures the discharge oil pressure and alarms and initiates a shut down when below a set value
?Heavy phase overflow. Oil has a much higher visccosity than water. The heavy phase outlet is led to asmall catchment tank containg a float. The outlet from the tank is restricted in such a way that water flows freely but oil tends to back up. This initiates an alarm and shut down
?Bowl not open- This may be dome in several ways, typically by a lever switch operated by the discharged sludge hitting a striker plate. A nouther method is by measuring the motor current, when the bowl opens the bowl speed is dragged down due to friction effects of the dischargeing sludge and water. The motor current rises until full speed is reestablished. This is detected by a current sensing relay
?Water in oil- This found on modern designs which have a detection probe mounted in the oil discharge
?High temperature alarm and shut down
?Low control/seal water pressure. Where control water is supplied via a fixed small header tanks a float switch may be fitted.
Other Designs
Sharples constant sludging
Heres one to send a shiver down the spine of anybody of my age.
This consisted essentially of a standard non desludging bowl into which were drilled small holes on the circumference fitted with nozzles. Seal water was pumped continuously from a small catchment tank mounted adjacent to the purifer into the bowl where it passed though to be ejected through the jets. It then drained to the catchment tank. Dirty oil would float to the surface where it would overflow though a surface mounted skimmer to the sludge tank. Theoretically the bowl could run for considerable periods without cleaning. The reality was one to two weeks, bowl cleaning included patiently trying to clear the small bore nozzles. I remember loading bunkers which were brick red, it contained lots of sand. The purifer was permenantly overflowing to an extent we had to use the second purifier to run on the sludge tank. Bowl cleans were every day with the other engineers playing the 'it best if one person concentrates on them' card. The worst aspect was the Chief Engineer who used to lie in wait for me when I was called out during the night. On sneaking back to for some sleep he would drag me into to his cabin ( which was next to mine) for a thank you drink- this inevitably lasted untill 8 am
Modern trends
The most obvious trend is that towars online sludging. In this during normal operation a small quanity of extra seal water is added and the bowl opened for an extremently short period of time thus removing the need to interupt the process.
Control and Operating water
Water must be supplied at a fixed pressure to ensure that the quantity supplied to the purifer is constant for the set parameters. The water normally comes from the vessels hot water system or is independently heated to reduce thermal shocking and to prevent cooling of the hot oil
Drive
Considerable torque would be required to direct drive the bowl upto speed using an appropriately sized electric motor. In addition very high loading would occur on the gear train, to prevent scuffing due to oil film breakdown would require large mating areas therby large gear trains which would again increase the starting load.
A centrifugal clutch arrangement is fitted which has between 2 and 6 ferrodo lined brake pads. These are designed to slip during the start up period and also to a much lesser extent during the speed up period after de-sludge. Purifer manufacturers will
usually quote a maximum and MINIMUM start up time. As the pads wear it may be necessary to remove and restore the mating surface to keep the start up time correct. As a last measure the number of pads should be altered
The electric motor may be of special design allowing for a long period of slight overload during the start up period.
The gear train is generally a single stage worm and wheel arrangement with the wheel being made of a softer material. Lubrication is normally splash only, the viscosity of the oil is essential to prevent wear as the form of lubrication is mainly boundary therefore the wear is governed by the viscosity and additives contained within the oil.
When wear occurs it will be scuffing and relative movement between the mating faces polishes out any pitting. As wear worsens galling occurs destroying the running surface. This damage is reflected in both elements therefore both should be changed.
As well as overload other causes of premature failure are poor design ( step forward westfalia), poor material choice, poor lube oil choice, too long a de-sludge period relative to supplied oil quality, out of balance bowl, failing bearing set in particular the vertical shaft upper resilient bearing arrangement
The use of planned maintenance is essential particularly with respect to bearing changes. It is strongly recommended to monitor condition using vibration analysis Bowl Cleaning
Should be carried out at regular intervals not exceeding manufacturers recommendations. Every care should be taken not to score the surfaces of the bowl especially the sliding surfaces for de-sludging types. The disc stack is generally numbered and should be built up as per this system as the stack is a balanced unit. Water washing
This was a techniques employed some time ago to improve purification of lube oil and to remove acids. It involved continuously adding a small quantity of water at oil temperature to the oil inlet which would pass through and overflow. This is much out of favour as it tends to remove the essential oil additives in particualr detergents. An alternative is to inject steam which improves the removal of colloidal carbon by causing it to coagulate
Typical Circuit
Shown is a typical circuit for a lube oil system although it can equally be applied to a fuel system. Control is achieved by the three way valve which eitherdiverst oil to recirculate or sends it to the purifer.
Oil flow rate is controlled by the oil control valve situated before the positive displacement delivery pump which is driven off the purifier horizontal shaft via a weak link arrangement
Back pressure from the purifer is controlled at oultet via the back pressure control valve
Gravitational
The most common type of oily water seperators found on ships are of the gravitational type. these rely on the difference in SG of the mix to seperate out the oil from the water
Shown above is a gravitational type seperator capable of very good quality effluent discharge. A safety valve (not shown) is mounted on the unit as are test cocks and a drain valve.
Operation
The unit is initially filled with purge water. The discharge from the pump has a sample line take of to a 15ppm monitor. This is lined up and in used with flushing water used until the pump is running. The unit activation button is pressed, the oil outlet valve is closed, the suction valve is opened and the discharge pump is started. Bilge water is drawn through the unit over a vertical arranged plate stack. The 15pp monitor is lined up to the pump discharge sample line
As oil coalescers it is led to the oil discharge chamber. As the oil here builds up the interface drops until the pump cut in probe is activated, the pump is stopped, the suction valve is closed, the oil discharge is opened and the purge water is opened. Oil is forced out of the oil outlet by the purge water.
When the oil water interface reaches the cut out the oil discharge valve and the purge water valve is closed. The suction valve is closed and the pump started. Alarms and shutdowns
Should the 15ppm equipment detect discharge with oil content over 15ppm it shuts the unit down and activates and alarm
When the pump cut out probe is activated a timer starts, should the oil interface not reach the pump cut in probe within a set time a alrm is sounded and the unit shutdown. Should the oil interface reach the alarm and shut down probe and alarm is activated and the unit shut down
Centrifugal seperators
Centrifugal seperators have been propsed for the use as oily water seperators. The quality of the output is determined by the throughput rate. The slower the flow of oil through the seperator the better quality output. A question mark exists over their ability to cope with fine emulsions and chemical pre-treatment is recommended.
Seperators capable of emulsion treatment
Gravitational seperators are not capable of operation with oil emulsions , or mixtures containing oil of high sg. Approaching 1 or above. The latter may be improved by the preheating of the mixture before or during the gravitatinal process. The former is more difficult, current regualtion requires the careful control of detergents capable of effecting the operation of the fitted seperator.
This means that modern efficient detergents containing surfactants may be only used in restricted quantities or not at all.
Alternatives to gravitational seperation are now becoming available capable of dealing with these mixtures. The most common at the moment involves the use of Polyaluminium Chloride. This causes the emulsified oil to join to gether (flock). The emulsion is thus broken and the water and oil seperated. Using this process very high quality effluent can be produced with little of no oil or chemical content. The cost is higher than for more conventional gravtiational seperators.
An alternative method is the useof Electrocoagulation. This relies on the three factors of a stable emulsion
-Ionic Charge
-Droplet or Particle Size
-Droplet or particle density
An electrical charge is passed through a scarificial anode made of aluminium. The released ions are attracted to the negatively charge fine droplets of contaminants. The overal effect is one of agglomeration with larger and larger droplet sizes being produced. In addition gas bubbles produced by hydrolysis attach to these droplets increasing there bouyancy. The seperated droplets rising to the surface may be removed. This is a very efficient process and large volumes can be coped with.