Types of mechanical seal technology

机械密封技术的种类

New technology, all kinds of machinery and the use of new materials and technologies of the seal of the rapid progress, new technology of mechanicalseal of the following. Sealing surface of grooved sealing technology in recent years, in the mechanical seal on the end face a variety of channels, to create a fluid static, dynamic pressure effect, still continue to update. Zero leakagesealing technology in the past that the total contact and non-contact typemechanical seal is not possible to achieve zero leakage (or no leakage). Sealing technology Israel using slotted, puts forward the new concept of zero leakage and non contacting mechanical face seal, and has been used in lubricating oil pump in nuclear power plant. Dry running gas sealing technology of the seal is to be slotted sealing technology for gas seal. The sealing technology is used on the sealing surface of the open slot downstream of small amount of leakage of fluid pumped back to the upstream upstream pumping. The structural characteristics of several kinds of sealing is: with shallow, deep are micron leveland film thickness and trough, and the lubricating groove, radial sealing dam andcircumferential sealing weir seal and bearing parts. Also can say the slotted sealis a combination of plane sealing and slotted bearing. The advantage of a small amount of leakage (or even no leakage), film thickness, eliminate the contactfriction, low power consumption and heat. The thermal fluid dynamic pressure seal technology is to use the various shapes of deep groove sealing surface,causing local thermal deformation, to produce the hydrodynamic wedge effect.The hydrodynamic pressure bearing capacity, known as heat sealing fluid dynamic wedge.

        当前采用新材料和工艺的各种机械密封的新技术，进展较快，有下列的机械密封新技术。密封面开槽密封技术近年来，在机械密封的密封端面上开了各种各样的流槽，以产生流体静、动压效应，现在还在不断更新。零泄漏密封技术过去总认为接触式和非接触式机械密封不可能达到零泄漏（或无泄漏）。上游泵送密封技术即利用密封面上开流槽将下游少量泄漏流体泵送回上游。上述几类密封的结构特点是：采用浅槽，且膜厚和流槽的深均属微米级，并采用润滑槽，径向密封坝和周向密封堰组成密封和承载部分。其优点是泄漏量小（甚至无泄漏）、膜厚大，消除接触摩擦、功耗和发热量小。热流体动压密封技术它是利用各种形状较深的密封面流槽，造成局部热变形，以产生流体动力楔效应。这种具有流体动压承载能力的密封，称之为热流体动力楔密封。

Bellows seal technology can be divided into forming metal corrugated pipe andwelded metal bellows mechanical seal technology.

波纹管密封技术可分为成型金属波纹管和焊接金属波纹管机械密封技术。

Multi end face sealing technology is divided into double sealed, intermediate ring seal, sealing technology. Another parallel plane sealing technology, sealingtechnology, sealing technology, monitoring combination.

多端面密封技术分为双密封、中间环密封、多密封技术。另外还有平行面密封技术、监控密封技术、组合密封技术等。

Mechanical seal washing solution and its characteristics

机械密封冲洗方案及特点

Flushing is to prevent impurities accumulation, prevent formation of air pockets,maintain and improve the lubrication, when washing liquid when the temperature is low, the functions of cooling effect. Rinse the way are as follows:

冲洗的目的在于防止杂质集积，防止气囊形成，保持和改善润滑等，当冲洗液温度较低时，兼有冷却作用。冲洗的方式主要有如下：

1) rinsing内冲洗

Rinse 正冲洗

Features: use host sealed medium, the pump outlet end of pipeline is introducedthrough the seal cavity.

特点：利用工作主机的被密封介质，由泵的出口端通过管路引入密封腔。

Application: used in cleaning fluid, P1 slightly larger than P, when the temperature is high or impurity, but cooler, filter is arranged in the pipeline.

Backwash

应用：用于清洁流体，p1稍大于p进，当温度高或有杂质时，可在管路上设置冷却器、过滤器等

Features: use host sealed medium, the pump outlet into the sealed cavity, after flushing the pipeline pump through the back entrance.

Application: used 

全冲洗

       特点：利用工作主机的被密封介质，由泵的出口端通过管路引入密封腔，冲洗后再经管路流回泵入口。
        应用：冷却效果优于前两种，用于清洁流体，且p1与p进和p出相接近 in cleaning fluid, and P.

 

Full irrigation

Features: use host sealed medium, the pump outlet end of pipeline is introducedthrough the seal cavity, rinse and then administered the road back to the pumpentrance.

Application: the cooling effect is better than the previous two, used for cleaningfluid, and P1 and P and P is close to.

2) external washing

Features: introducing the outside of washing and cleaning fluid sealed mediumcompatible to the sealing cavity.

Application: the external fluid pressure than the sealed medium 0.05--0.1MPa,suitable for medium to high temperature or solid   2）外冲洗
        特点：引入外系统与被密封介质相容的清洁流体至密封腔进行冲洗。
        应用：外冲洗液压力应比被密封介质大0.05--0.1MPa，适用于介质为高温或固体颗粒的场合。冲洗液的流量应保证带走热量，还需满足冲洗的需要，不会产生对密封件的冲蚀。为此，需控制密封腔的压力和冲洗的流速，一般清洁冲洗液的流速应小于5m/s;含有颗粒的浆

particles. Flushing fluid flowshould guarantee the heat away, needed to meet the irrigation needs, noerosion on the seal. Therefore, need to control the seal chamber pressure andflushing flow rate, the general cleaning fluid flow rate should be less than 5m/sparticles containing pulp;

状液体须小于3m/s，为达到上述的流速值，冲洗液与密封腔压力的差值应<0.5MPa，一般取0.05--0.1MPa，对双端面机械密封可取0.1--0.2MP.冲洗液进入和排出密封腔的孔口位置，应设置在密封端面附近，且应在靠近动环侧，为了防止石墨环被冲蚀或因冷却不均引起温差变形，以及杂质堆积和结焦等，可采用切向引入或多点冲洗.必要时，冲洗液可以是热水或蒸汽。

Liquid shall be less than 3m/s, in order to achieve the values of the flow velocity,fluid pressure in the seal cavity and the difference should be <0.5MPa, general0.05--0.1MPa, the position of the orifice desirable 0.1--0.2MP. flushing fluid inlet and outlet seal cavity of the double end mechanical seal, the sealing surfaceshould be set up in the nearby, and near the ring side, in order to prevent the graphite the ring is erosion or because of uneven cooling caused bytemperature and deformation, and the accumulation of impurities and coking, thetangential introduced or more flush. When necessary, the washing fluid can behot water or steam.

填料密封：石墨盘根，四氟盘根，高水基盘根，芳纶纤维盘根，油浸石棉盘根，棉纱盘根，碳纤维盘根等