原文:
疏水阀在蒸汽加热系统中起到阻汽排水作用,选择合适的疏水阀,可使蒸汽加热设备达到{zg}工作效率。要想达到最理想的效果,就要对各种类型疏水阀的工作性能、特点进行全面的了解。
疏水阀的品种很多,各有不同的性能。选用疏水阀时,首先应选其特性能满足蒸汽加热设备的{zj0}运行,然后才考虑其他客观条件,这样选择你所需要的疏水阀才是正确和有效的。疏水阀要能“识别"蒸汽和凝结水,才能起到阻汽排水作用。“识别" 蒸汽和凝结水基于三个原理:密度差、温度差和相变。于是就根据三个原理制造出三种类型的疏水阀:分类为机械型疏水阀、热静力型疏水阀、热动力型疏水阀。
一、机械型疏水阀 机械型也称浮子型,是利用凝结水与蒸汽的密度差,通过凝结水液位变化,使浮子升降带动阀瓣开启或关闭,达到阻汽排水目的。机械型疏水阀的过冷度小,不受工作压力和温度变化的影响,有水即排,加热设备里不存水,能使加热设备达到{zj0}换热效率。{zd0}背压率为80%,工作质量高,是生产工艺加热设备最理想的疏水阀。
机械型疏水阀又可分为自由浮球式疏水阀、自由半浮球式疏水阀、杆浮球式疏水阀、倒吊桶式等
1、自由浮球式疏水阀
自由浮球式疏水阀的结构简单,内部只有一个活动部件精细研磨的不锈钢空心浮球,既是浮子又是启闭件,无易损零件,使用寿命很长,疏水阀内部带有Y系列自动排空气装置,非常灵敏,能自动排空气,工作质量高。
设备刚启动工作时,管道内的空气经过Y系列自动排空气装置排出,低温凝结水进入疏水阀内,凝结水的液位上升,浮球上升,阀门开启,凝结水迅速排出,蒸汽很快进入设备,设备迅速升温,Y系列自动排空气装置的感温液体膨胀,自动排空气装置关闭。疏水阀开始正常工作,浮球随凝结水液位升降,阻汽排水。自由浮球式疏水阀的阀座总处于液位以下,形成水封,无蒸汽泄漏,节能效果好。最小工作压力0.01Mpa,从0.01Mpa至{zg}使用压力范围之内不受温度和工作压力波动的影响,连续排水。能排饱和温度凝结水,最小过冷度为0℃,加热设备里不存水,能使加热设备达到{zj0}换热效率。背压率大于85%,是生产工艺加热设备最理想的疏水阀之一。
2、自由半浮球式疏水阀
自由半浮球式疏水阀只有一个半浮球式的球桶为活动部件,开口朝下,球桶即是启闭件,又是密封件。整个球面都可为密封,使用寿命很长,能抗水锤,没有易损件,无故障,经久耐用,无蒸汽泄漏。背压率大于80%,能排饱和温度凝结水,最小过冷度为0℃,加热设备里不存水,能使加热设备达到{zj0}换热效率。
当装置刚启动时,管道内的空气和低温凝结水经过发射管进入自由半浮球式疏水阀内,阀内的双金属片排空元件把球桶弹开,阀门开启,空气和低温凝结水迅速排出。当蒸汽进入球桶内,球桶产生向上浮力,同时阀内的温度升高,双金属片排空元件收缩,球捅漂向阀口,阀门关闭。当球桶内的蒸汽变成凝结水,球桶失去浮力往下沉,阀门开启,凝结水迅速排出。当蒸汽再进入球桶之内,阀门再关闭,间断和连续工作。
3、杆浮球式疏水阀
杆浮球式疏水阀基本特点与自由浮球式相同,内部结构是浮球连接杠杆带动阀心,随凝结水的液位升降进行开关阀门。杆浮球式疏水阀利用双阀座增加凝结水排量,可达到体积小排量大,{zd0}疏水量达100吨/小时,是大型加热设备最理想的疏水阀。
4、倒吊桶式疏水阀
倒吊桶式疏水阀内部是一个倒吊桶为液位敏感件,吊桶开口向下,倒吊桶连接杠杆带动阀心开闭阀门。倒吊桶式疏水阀能排空气,不怕水击,抗污性能好。过冷度小,漏汽率小于3%,{zd0}背压率为75%,连接件比较多,灵敏度不如自由浮球式疏水阀。因倒吊桶式疏水阀是靠蒸汽向上浮力关闭阀门,工作压差小于0.1MPA时,不适合选用。
当装置刚启动时,管道内的空气和低温凝结水进入疏水阀内,倒吊桶靠自身重量下坠,倒吊桶连接杠杆带动阀心开启阀门,空气和低温凝结水迅速排出。当蒸汽进入倒吊桶内,倒吊桶的蒸汽产生向上浮力,倒吊桶上升连接杠杆带动阀心关闭阀门。倒吊桶上开有一小孔,当一部份蒸汽从小孔排出,另一部份蒸汽产生凝结水,倒吊桶失去浮力,靠自身重量向下沉,倒吊桶连接杠杆带动阀心开启阀门,循环工作,间断排水。
5、组合式过热蒸汽疏水阀:
组合式过热蒸汽疏水阀有两个隔离的阀腔,由两根不锈钢管连通上下阀腔,它是由自由浮球式疏水阀和倒吊桶式疏水阀的组合,该阀结构先进合理,在过热、高压、小负荷的工作状况下,能够及时地排放过热蒸汽消失时形成的凝结水,有效地阻止过热蒸汽泄漏,工作质量高。{zg}允许温度为600℃,阀体为全不锈钢,阀座为硬质合金钢,使用寿命长,是过热蒸汽专用疏水阀,取得两项国家专利,填补了国内空白。
当凝结水进入下阀腔,副阀的浮球随液位上升,浮球封闭进汽管孔。凝结水经进水导管上升到主阀腔,倒吊桶靠自重下坠,带动阀心打开主阀门,排放凝结水。当副阀腔的凝结水液位下降时,浮球随液位下降,副阀打开。蒸汽从进汽管进入上主阀腔内的倒吊桶里,倒吊桶产生向上的浮力,倒吊桶带动阀心关闭主阀门。当副阀腔的凝结水液位再升高时,下一个循环周期又开始,间断排水。
二、热静力型疏水阀 这类疏水阀是利用蒸汽和凝结水的温差引起感温元件的变型或膨胀带动阀心启闭阀门。热静力型疏水阀的过冷度比较大,一般过冷度为15度到40度,它能利用凝结水中的一部分显热,阀前始终存有高温凝结水,无蒸汽泄漏,节能效果显著。是在蒸汽管道,伴热管线、小型加热设备,采暖设备,温度要求不高的小型加热设备上,最理想的疏水阀 。
热静力型疏水阀有膜盒式、波纹管式、双金属片式
1、膜盒式式疏水阀
膜盒式式疏水阀的主要动作元件是金属膜盒,内充一种气化温度比水的饱和温度低的液体,有开阀温度低于饱和温度15℃和30℃两种供选择。膜盒式式疏水阀的反应特别灵敏,不怕冻,体积小,耐过热,任意位置都可安装。背压率大于80%,能排不凝结气体,膜盒坚固,使用寿命长,维修方便,使用范围很广。
装置刚起动时,管道出现低温冷凝水,膜盒内的液体处于冷凝状态,阀门处于开启位置。当冷凝水温度渐渐升高,膜合内充液开始蒸发,膜合内压力上升,膜片带动阀心向关闭方向移动,在冷凝水达到饱和温度之前,疏水阀开始关闭。膜盒随蒸汽温度变化控制阀门开关,起到阻汽排水作用。
2、波纹管式疏水阀
波纹管式疏水阀的阀芯不锈钢波纹管内充一种汽化温度低于水饱和温度的液体。随蒸汽温度变化控制阀门开关,该阀设有调整螺栓,可根据需要调节使用温度,一般过冷度调整范围低于饱和温度15℃-40℃。背压率大于70%,不怕冻,体积小,任意位置都可安装,能排不凝结气体,使用寿命长。
当装置启动时,管道出现冷却凝结水,波纹管内液体处于冷凝状态,阀心在弹簧的弹力下,处于开启位置。当冷凝水温度渐渐升高,波纹管内充液开始蒸发膨胀,内压增高,变形伸长,带动阀心向关闭方向移动,在冷凝水达到饱和温度之前,疏水阀开始关闭,随蒸汽温度变化控制阀门开关,阻汽排水。
3、双金属片式疏水阀
双金属片式疏水阀的主要部件是双金属片感温元件,随蒸汽温度升降受热变形,推动阀心开关阀门。双金属片式疏水阀设有调整螺栓,可根据需要调节使用温度,一般过冷度调整范围低于饱和温度15℃-30℃,背压率大于70%,能排不凝结气体,不怕冻,体积小,能抗水锤,耐高压,任意位置都可安装。双金属片有疲劳性,须要经常调整。
当装置刚起动时,管道出现低温冷凝水,双金属片是平展的,阀心在弹簧的弹力下,阀门处于开启位置。当冷凝水温度渐渐升高,双金属片感温起元件开始弯曲变形,并把阀心推向关闭位置。在冷凝水达到饱和温度之前,疏水阀开始关闭。双金属片随蒸汽温度变化控制阀门开关,阻汽排水。
三、热动力型疏水阀
这类疏水阀根据相变原理,靠蒸汽和凝结水通过时的流速和体积变化的不同热力学原理,使阀片上下产生不同压差,驱动阀片开关阀门。因
热动力式疏水阀的工作动力来源于蒸汽,所以蒸汽浪费比较大。结构简单、耐水击、{zd0}背为50%,有噪音,阀片工作频繁,使用寿命短。
热动力型疏水阀有热动力式(圆盘式疏水阀)、脉冲式、孔板式
1、热动力式疏水阀
热动力式疏水阀内有一个活动阀片,既是敏感件又是动作执行件。根据蒸汽和凝结水通过时的流速和体积变化的不同热力学原理,使阀片上下产生不同压差,驱动阀片开关阀门。漏汽率3%,过冷度为8℃-15℃。
当装置启动时,管道出现冷却凝结水,凝结水靠工作压力推开阀片,迅速排放。当凝结水排放完毕,蒸汽随后排放,因蒸汽比凝结水的体积和流速大,使阀片上下产生压差,阀片在蒸汽流速的吸力下迅速关闭。当阀片关闭时,阀片受到两面压力,阀片下面的受力面积小于上面的受力面积,因疏水阀汽室里面的压力来源于蒸汽压力,所以阀片上面受力大于下面,阀片紧紧关闭。当疏水阀汽室里面的蒸汽降温成凝结水,汽室里面的压力消失。凝结水靠工作压力推开阀片,凝结水又继续排放,循环工作,间断排水。
2、圆盘式蒸汽保温型疏水阀
圆盘式蒸汽保温型疏水阀疏水阀的工作原理和热动力式疏水阀相同,它在热动力式疏水阀的汽室外面增加一层外壳。外壳内室和蒸汽管道相通,利用管道自身蒸汽对疏水阀的主汽室进行保温。使主汽室的温度不易降温,保持汽压,疏水阀紧紧关闭。当管线产生凝结水,疏水阀外壳降温,疏水阀开始排水;在过热蒸汽管线上如果没有凝结水产生,疏水阀不会开启,工作质量高。阀体为合金钢,阀心为硬质合金,该阀{zg}允许温度为550℃,经久耐用,使用寿命长,是高压、高温过热蒸汽专用疏水阀。
3、脉冲式疏水阀
脉冲式疏水阀有和两个孔板根据蒸汽压降变化调节阀门开关,即使阀门xx关闭入口和出口也是通过{dy}、第二个小孔相通,始终处于不xx关闭状态,蒸汽不断逸出,漏汽量大。该疏水阀动作频率很高,磨损厉害、寿命较短。体积小、耐水击,能排出空气和饱和温度水,接近连续排水,{zd0}背压25%,因此使用者很少。
4、孔板式疏水阀 孔板式疏水阀是根据不同的排水量,选择不同孔径的孔板控制排水量的目的。结构简单,选择不合适会出现排水不及或大量跑汽,不适用于间歇生产的用汽设备或冷凝水量波动大的用汽设备。
“ Classification and principle of the trap ”是由提供的国际阀门新闻,译文仅供参考。另外,中国疏水阀网还提供相关产品搜索: 、 、 、 、 、 、 、 、 等。
译文:
Traps the steam heating system in a blocking air drainage, select the appropriate traps, steam heating device can achieve maximum efficiency. To achieve optimal results, we should work on all types of steam trap performance, feature a comprehensive understanding.
Steam traps many varieties, each with different performance. Steam traps, the first of its characteristics should be selected to meet the steam heating equipment, the best run, before considering other objective conditions, such choices you need to trap is the correct and effective. Traps should be able to "identify" the steam and condensed water can play a blocking air drainage. "Recognition" of steam and condensate based on three principles: the density difference, temperature, difference of change. So on the basis of three principles of creating three types of traps: classified as mechanical-type traps, thermostatic type steam traps, thermodynamic type steam traps.
A mechanical-type traps mechanical type, also known as float type, is the use of steam condensate and the density difference, by condensation of water level changes so that the float valve down to open or close the valve drive to achieve the purpose of blocking water vapor. Mechanical-type traps, the undercooling is small, from working pressure and temperature changes, water that is exclusive, not heating equipment in storage, can achieve the best heat transfer efficiency heating equipment. 80% of the maximum back pressure, the work of high quality production process heating equipment is the best trap.
Mechanical-type traps can be divided into the free float-type traps, the free semi-float type trap, pole float-type traps, inverted bucket type, etc.
1, Free Float Steam Trap
Free float-type trap is simple, only one moving part within the fine grinding of stainless steel hollow float, float is both open and close parts, no wearing parts, long service life, steam traps with Y series automatic row-house air devices, very sensitive, automatically scheduling the air, high quality work.
Equipment has just started work, the pipeline of the air through the Y series automatic discharging exhaust air devices, low temperature condensate into the trap, the condensate water level rise, float up, the valve opens, the rapid discharge condensate, steam soon into the equipment, equipment rapid warming, Y series automatic scheduling of air temperature of liquid expansion devices, automatic scheduling of air device closed. Traps started work, with the condensate level float down, waste gas drainage. Free ball float type steam trap valve seat total in the level below, forming a water seal, no steam leakage, energy saving effect is good. Minimum working pressure 0.01Mpa, to the maximum use from 0.01Mpa pressure from within the temperature and working pressure fluctuations, continuous drainage. Condensate saturation temperature can be row, the minimum undercooling to 0 ℃, heating equipment is not in storage, can achieve the best heat transfer efficiency heating equipment. Back pressure more than 85%, the production process heating equipment, one of the best traps.
2, free half-float-type traps
Free half-float-type traps only one and a half barrels for the ball float type moving parts, opening down, the ball bucket that is open and close cases, but also seals. The sphere can be a closed, long service life, resistant to water hammer, no wearing parts, trouble-free, durable, no steam leakage. Back pressure higher than 80%, to row condensate saturation temperature, the minimum undercooling to 0 ℃, heating equipment is not in storage, can achieve the best heat transfer efficiency heating equipment.
When the device has just started, the air inside the tubes and the low temperature condensation of water through the launch tube into the free half-float-type traps, the valve within the dual-metal barrel emptying device to bounce the ball valve opening, air and low-temperature condensation water to a rapid discharge. When the steam drum into the ball, the ball barrels produced upward buoyancy, and temperature inside the valve, double metal components emptying contraction, poke the ball float to the valve port, the valve closed. When the ball into a bucket of steam condensate, loss of buoyancy to sink the ball bucket, valve opening, condensation water to a rapid discharge. When the steam re-entered the ball barrel, and then close the valve, intermittent and continuous work.
3, lever ball float type steam trap
Lever ball float type steam trap basically the same features and free float type, the internal structure is driven leveraged float valve connecting heart, with the condensation of water level down to switch the valve. Lever ball float type steam trap condensate using two-seat increase in displacement, small displacement can reach large size, the largest drainage capacity of 100 tons / hour, is the major heating equipment, the best traps.
4, inverted bucket-type traps
Inverted Bucket Steam Trap is an inverted bucket inside for the level-sensitive parts, bucket opening down, inverted bucket link lever driven heart valve opening and closing the valve. Inverted bucket type steam traps can row of air, not afraid of water hammer, dirt good performance. Undercooling small steam leakage rate of less than 3%, the maximum back pressure was 75%, connectors are more sensitive than the free float-type traps. By inverted bucket type steam traps are up by buoyancy close the valve, when the work pressure is less than 0.1MPA not suitable for use.
When the device has just started, the air inside the tubes and the low temperature inside the condensate into the steam trap, inverted bucket by its own weight to fall, driven down bucket link lever to open the valve heart valve, air and cold condensate discharge rapidly. When the steam into the inverted buckets, the inverted bucket steam generated upwards buoyancy, pour buckets up lever drive connected heart valves close the valve. Pour a bucket on the opening hole, when a part of the steam discharged from the hole, the other part of the steam condensate produced, inverted bucket to lose buoyancy, by its own weight goes down, inverted bucket valve connecting the heart, opening the valve lever drive, cycle work, intermittent drainage.
Five, combination of superheated steam steam traps:
Superheated steam traps combined two separate valve chamber, connected by the two stainless steel valve chamber up and down, which is a free float-type traps and inverted bucket-type traps combination of advanced and reasonable structure of the valve in the hot , high pressure, low load conditions of work can disappear in time when the discharge of superheated steam condensate formed to effectively prevent leakage of superheated steam, high quality work. Maximum allowable temperature is 600 ℃, valve body made of stainless steel, alloy steel valve seat for the long life, is the exclusive steam traps, achieved two national patents, to fill the gap.
When the condensation of water into the cavity under the valve, float valve with the level deputy rise into the steam float closed pores. Condensate increased by the water pipe to the main valve cavity, inverted bucket by gravity to fall, driven to open the main valve heart valve, discharge condensate. When the deputy valve chamber condensate level falls, the float with the liquid level, the Deputy valve is opened. Steam into the steam pipe from the main valve chamber into the inverted bucket, the bucket back up the buoyancy generated, inverted bucket drive close the main valve heart valve. When the deputy valve chamber condensate level rises again, the next cycle began, intermittent drainage.
Second, thermostatic type steam traps of such traps is to use the temperature difference between steam and condensate caused by temperature variations or component of the heart valves open and close valves expansion drive. Thermostatic type steam traps relatively large undercooling, the general undercooling of 15 degrees to 40 degrees, it can use part of condensation water was hot, the valve is always there before the high-temperature condensation of water, no steam leakage, energy-saving effect is remarkable . In steam pipes, heating pipes, small heating equipment, heating equipment, temperature, do not ask for a small heating device, the best trap.
Thermostatic type steam traps are bellows, bellows type, double-metal piece
1, bellows-type traps
Bellows-type trap is the main component of metal diaphragm movement, which charge a gasification temperature lower than the saturation temperature of water in the liquid, open valve temperature below saturation temperature of 15 ℃ and 30 ℃ are two choices. Bellows-type traps particularly sensitive response, plumbing, small size, resistance to overheating and can be installed anywhere. Back pressure higher than 80%, to row non-condensing gas, diaphragm solid, long life, easy maintenance, using a wide range.
Device just starting, the pipeline occurs at low temperature condensate in the condensate liquid film box state, the valve in the open position. When the condensate water temperature gradually increased cooperation within the fluid-filled membrane began to evaporate, the pressure inside the membrane combined increase in heart turned to close the valve diaphragm driven move, in condensing saturated temperature of water before the trap began to close. Diaphragm control valve with the steam temperature switch, play blocking air drainage.
2, bellows-type traps
Bellows-type trap-filled stainless steel bellows valve vaporization temperature is lower than a kind of liquid water saturation temperature. With the steam temperature control valve switch, the valve has to adjust bolt, can be adjusted according to temperature, adjust the general scope of the undercooling below the saturation temperature of 15 ℃ -40 ℃. Back pressure greater than 70%, plumbing, small size, can be installed anywhere, to row non-condensing gas, long service life.
When the device starts, the pipeline appears condensate cooling, bellows at the condensing fluid, heart valve spring stretch, the in the open position. When the condensate water temperature gradually increased within the liquid-filled bellows expansion began to evaporate, the internal pressure increased, deformation elongation, promote heart turned to close the valve moves in the condensate to saturation temperature before the trap began to close, with the steam temperature control valve switch, waste gas drainage.
3, double-metal chip trap
Bimetal the main components of the trap is bimetal temperature sensing element, with the steam heat distortion temperature down, and promote heart valve switch valve. Bimetal traps with adjustment bolt can be used to adjust the temperature according to the general scope of the undercooling below the saturation temperature adjustment 15 ℃ -30 ℃, back pressure greater than 70%, to row non-condensing gas, plumbing , small size, resistant to water hammer, high pressure, can be installed anywhere. Bimetallic nature of fatigue, need regular revision.
When the device is just starting, the pipeline occurs at low temperature condensation of water, two metal sheets are flat, and valve heart in the spring will, the valve in the open position. When the condensate water temperature gradually increased from the bimetal temperature sensing element start bending and push the valve closed position heart. Saturation temperature in the condensate before the steam trap to close. Bimetal temperature control valve with the steam switch, waste gas drainage.
Third, thermal power-type traps
Phase transition under the principle of such traps, by the passage of steam and condensate flow rate and volume changes in different thermodynamics, so that the valve have different pressure levels, driven valves switch valves. Because of thermodynamic steam traps from the work force, so relatively large waste of steam. Simple structure, water attack, the biggest back to 50%, the noise and the valve work frequently, short life.
Thermodynamic steam traps with thermodynamic model (disc traps), pulse type, orifice plate
1, thermodynamic steam trap
Thermodynamic Steam Trap valve within an activity, is sensitive to is the action, pieces of pieces. According to the passage of steam and condensate flow rate and volume changes of different thermodynamics, so that the valve have different pressure levels, driven valves switch valves. Steam leakage rate of 3%, the undercooling is 8 ℃ -15 ℃.
When the device starts, pipe cooling off condensed water condensed water by pushing the valve working pressure, rapid discharge. When the condensed water discharge is completed, the subsequent emission of steam, due to condensation of water vapor than the volume and velocity, to generate pressure up and down the valve, the valve in the suction flow rate of steam rapidly closing. When the valve is closed, both sides of the valve under pressure, valve area of less than following the force above the force area, steam room, due to the pressure of the trap from the steam pressure, so the valve is greater than the force above the following, valves tightly closed. When the steam trap steam room, steam condenses into water cooling, steam room, the pressure disappears. Condensation of water by pushing the valve working pressure, continued to discharge condensate, cyclic work, intermittent drainage.
2, disc-type steam traps heat
Disc Type Steam Traps Traps heat and the thermodynamic principle of the same trap, its thermodynamic steam trap chamber shell out an additional layer. Steam pipe within the enclosure chamber and connected, using their own steam to the trap pipe Steam Room insulation. So that the temperature of main steam room temperature is not easy to maintain steam pressure, trap firmly shut. When the pipeline produces condensate, trap enclosure cooling, the trap begins to drain; in the superheated steam pipe on the absence of condensate production, trap does not open, the work of high quality. Body for the steel, as carbide heart valve, the valve allows a maximum temperature of 550 ℃, durable, long life, is a high-pressure, high temperature and an exclusive steam traps.
3, pulse-type traps
Pulse and two orifice traps are down according to changes in vapor pressure regulating valve switch, even if the valve is completely closed the entrance and exit is through the first and the second hole connected, always not fully closed, the steam constantly Yat out
steam leakage large. The high frequency of the trap action, severe wear and tear, shorter life expectancy. Small, water-strike, can expel the air and the saturation temperature of water, close to the continuous drainage, the maximum back pressure of 25%, so very few users.
4, orifice plate steam trap orifice plate steam trap is different from the displacement, select a different aperture of the plate displacement control purposes. Simple structure, appears to inappropriate choice of less or a lot of running water vapor, does not apply to the use of intermittent production equipment or condensation of water vapor volatile the use of equipment
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