渣浆泵机械密封的选用与适用于那种
    (1)强腐蚀性介质:选用外装式机封或波纹管机封，如果采用内装式时要对弹簧进行防腐保护措施。对摩擦副材料也应采用耐磨材料，如四氟陶瓷等。
    (2)易汽化介质:选用平衡型或双端面机械密封。
    (3)含盐及易结晶介质:选用双端面机械密封;摩擦副采用硬对硬材料，弹簧采用大弹簧，用冲洗液进行“封堵”措施。
    (4) 含固体颗粒介质:选用双端面机械密封，靠近介质侧选择静止内流式结构。摩擦副采用硬对硬材料。冲洗液加旋液分离器或外供冲洗液冲洗。弹簧要采用大弹簧结构。
    (5) 高黏度介质:选用静止型双端面机械密封，摩擦副采用硬对硬材料组合。
    (6) 高温介质:密封材料要进行稳定热处理，且膨胀系数相近。用单端面机械密封，端面宽度尽量小，需充分冷却冲洗。采用双端面机械密封，需外供循环液。温度超过250C，采用金属波纹管式机械密封，但要注意金属波纹管的承压能力。辅助密封材料也应选择相应温度的材料。
    (7)低温介质:介质温度高于- 45C时可选用单端面机封。介质温度高于-100C时，选用波纹管机封。介质温度低于-100C时， 选用静止式波纹管机封，波态烃建议选用双端面机械密封。摩擦副材料选择青铜填充聚四氟乙烯。辅助密封材料也应该选择相应温度的材料。

(8)高压介质:当压力p>0.7MPa。应选择平衡型机封，当压力较高时， 在保证允许的最小端面比压条件下，应选择较大平衡系数，但不大于0.5。当压力p>15MPa时，宜采用串联机封，逐步降低没级密封压力、摩擦副材料宜用碳化钨对浸渍金属石墨，或硬对硬材料，如硬质合金、陶瓷等。O形圈的肖氏硬度应大于80，并用隔离支承圈以防被挤出。

(9)高速:当速度n>25m/s时，采用静止式机封，动环与轴直接配合利用轴套和叶轮夹紧来传递力矩，而不主张用键、销来传通，以减小不平衡力的影响。要用最小的密封端面摩擦系数，端面宽度尽量小，加强冷却与润滑。

(10)正反转:应采用金属波纹管机封、或小弹簧结构机械密封。渣浆泵厂家

Selection and application of mechanical seal for slurry pump

(1) strong corrosive medium: external mechanical seal or bellows mechanical seal shall be selected. If internal type is adopted, anti-corrosion protection measures shall be taken for spring. Wear resistant materials, such as Teflon ceramics, should also be used for friction pairs.

(2) vaporizable medium: balanced or double face mechanical seal is selected.

(3) salt containing and crystallizable medium: double face mechanical seal is selected; hard to hard material is used for friction pair, large spring is used for spring, and "plugging" measures are taken with flushing liquid.

(4) medium containing solid particles: double face mechanical seal is selected, and static internal flow structure is selected near the medium side. The friction pairs are made of hard to hard materials. The flushing liquid is added to the liquid separator or supplied to the outside for flushing. The spring shall be of large spring structure.

(5) high viscosity medium: static double face mechanical seal is selected, and hard to hard material combination is used for friction pair.

(6) high temperature medium: the sealing material shall be subject to stable heat treatment with similar expansion coefficient. Use single face mechanical seal, the width of the end face shall be as small as possible, and it shall be fully cooled and flushed. Adopt double face mechanical seal, need to supply circulating liquid. If the temperature exceeds 250C, metal bellows mechanical seal shall be adopted, but the pressure bearing capacity of metal bellows shall be paid attention to. The auxiliary sealing material shall also be selected at the corresponding temperature.

(7) low temperature medium: when the medium temperature is higher than - 45C, single end mechanical seal can be selected. When the medium temperature is higher than - 100C, the bellows mechanical seal is selected. When the medium temperature is lower than - 100C, static bellows mechanical seal is selected, and double face mechanical seal is recommended for wavy hydrocarbon. The material of friction pair is bronze filled polytetrafluoroethylene. The auxiliary sealing material should also be selected at the corresponding temperature.

(8) high pressure medium: when the pressure P > 0.7MPa. Balance type mechanical seal shall be selected. When the pressure is high, under the condition of ensuring the minimum allowable end face specific pressure, a larger balance coefficient shall be selected, but not more than 0.5. When the pressure P > 15MPa, the series mechanical seal should be used to gradually reduce the level of sealing pressure, the tungsten carbide impregnated metal graphite or hard to hard materials, such as cemented carbide, ceramics, etc. should be used as the friction materials. The O-ring shall have a shore hardness greater than 80 and be supported by an isolating ring to prevent extrusion.

(9) high speed: when the speed is n > 25m / s, the static mechanical seal is adopted. The dynamic ring and shaft are directly matched to use the shaft sleeve and impeller to clamp to transmit the torque, instead of the key and pin to transmit, so as to reduce the influence of the unbalanced force. It is necessary to use the minimum friction coefficient of the sealing end face and the width of the end face as small as possible to strengthen the cooling and lubrication.

(10) forward and reverse: metal bellows mechanical seal or small spring structure mechanical seal shall be adopted. Slurry pump manufacturer