---

DVS Series Dry Screw Vacuum Pumps

Dry screw vacuum pumps do not use liquid as the sealing fluid. Instead, they are vacuum equipment that uses the suction and exhaust functions generated by the synchronous high-speed reverse rotation of a pair of screw rotors in the pump chamber. The two screw rotors are precisely balanced and supported by bearings and installed in the pump chamber. There is a certain gap between the screws and they have no friction with each other. The operation is smooth and the noise is low. The working chamber does not require lubricating oil. Therefore, dry screw vacuum pumps can be used in gas extraction scenarios containing a large amount of water vapor and a small amount of dust. Because gas compression will cause a higher temperature at the exhaust port, dry screw vacuum pumps do not facilitate the formation of a condensation effect, which is conducive to the discharge of some high vapor pressure media such as dichloromethane and acetone in the form of gas from the exhaust port.

In many chemical and pharmaceutical applications, vacuum pumps are needed to extract excess solvents from the process flow, such as drying, distillation, concentration and purification, cleaning, etc. Many organic solvents need to be recycled due to their toxicity, flammability, and environmental impact. And dry screw vacuum pumps can achieve excellent recycling. The solvent vapor passes through the dry screw vacuum pump and is directly recovered through a condenser at the exhaust port without pollution.

If a higher pumping speed is required, a vacuum unit combining Roots vacuum pump and dry screw vacuum pump can be used.

DVS 系列干式螺杆真空泵                                                                                            
      干式螺杆真空泵不使用液体作为密封液，而是利用一对螺杆转子在泵腔中作同步高速反向旋转而产生的吸气和排气作用的抽气设备。两螺杆转子经精

细动平衡校正，由轴承支撑安装在泵腔中，螺杆与螺杆之间都有保持一定的间隙相互之间无磨擦，运转平稳，噪音低，工作腔无需润滑油，因此干式螺杆真空泵能适用于抽除含有大量水蒸汽及少量粉尘的气体场合。因为气体压缩会导致排气口较高的温度，所以干式螺杆真空泵内部不利于产生冷凝效应，利于一些高蒸汽压的介质如二氯甲烷、丙酮 等以气相从排气口排出。
      在许多化学和制药应用中，需要真空泵抽出工艺流程中多余的溶剂，像干燥、蒸馏、浓缩提纯、清洗等等应用。许多有机溶剂由于其毒性、易燃性、对环境影响等原因需要重新回收。而干式螺杆真空泵就能非常好的来实现回收，溶剂蒸气在通过干式螺杆真空泵后，直接在排气口通过冷凝器回收，没有污染。
      如果需要更高的抽速能力，可以使用罗茨真空泵与干式螺杆真空泵组合的真空机组。

The features of the dry screw vacuum pump are as follows:

◆ Dual screw pumping: No contact compression, the rotors do not wear, and the operation is reliable.

◆ High vacuum degree: It can independently achieve a stable pumping speed from atmospheric pressure to 1 Torr (133 Pa), and the vacuum pressure performance is not affected by environmental, seasonal, or working condition changes.

◆ No oil or water in the pump chamber: The process flow of the dry screw vacuum pump has no oil or water, and there is no wastewater or waste oil generation, which can greatly reduce pollution. It allows the use of nitrogen, steam, and solvent to flush the pump body.

◆ Corrosion-resistant design: Through special coating treatment, it can be used to transport toxic, corrosive, and condensable gases.

◆ Smooth exhaust port structure: The gas path is short, enabling the gas to be quickly discharged. The direct-through pump body structure can carry liquid and is conducive to handling the liquid condensate and the discharge of tiny particles. It has excellent liquid processing capabilities, and the exhaust port can directly recover solvents and some valuable process solvents.

◆ Spiral jacket cooling structure: The spiral jacket has excellent cooling effect, low operating temperature, and the unique jacket water cooling structure can reduce the outlet temperature to meet or approach the T4 requirements.

◆ Reliable and durable sealing structure: It uses mechanical seals and lip seals. According to the working condition requirements, air and nitrogen barriers can be set before the mechanical seals to prevent dust and other impurities from entering the pump.

◆ IEC flange: The C flange design is convenient for installation, reduces noise, solves the alignment problem of the coupling, and increases the thread to prevent deformation and vibration. 

Characteristics of the constant pitch screw vacuum pump

● No internal compression, so steam is less likely to be compressed and condensed within the pump

● Even at high vacuum levels, it can maintain the highest pumping rate 

The characteristics of variable pitch screw vacuum pump

● Lower exhaust temperature

● Internal compression exists, resulting in lower energy consumption 

Applications:

◆Chemical and Pharmaceutical Industry – Distillation, Drying, Concentration, Solvent Recovery, Dehydration, Molecular Distillation

◆Food Industry – Freeze Drying, Packaging

◆Electronic Industry – Chemical Vapor Deposition, Dry Etching, Photovoltaics

◆Industrial Furnaces – Welding, Ovens, Sintering, Heat Treatment

◆Aerospace and Aviation – Wind Tunnels, Space Simulation Experiments

干式螺杆真空泵所具有的特点：
◆采用双螺杆抽气：无接触式压缩，转子没有磨损，运行可靠。
◆高真空度：可以独立获得从大气压到1Torr（133Pa）能保持稳定抽速，真空压力性能不受环境、季节、工况条件变化影响。
◆泵腔内无油无水：干式螺杆真空泵的工艺流程内无油无水，没有废水或是废油的产生，可大大减少污染，允许使用氮气、蒸汽、溶剂冲洗泵体。
◆防腐蚀设计：经过特殊涂层处理可以用于输送有毒、有腐蚀性和可凝性的气体。
◆通畅的排气口结构：气体通路短，可使气体快速排出，直通式的泵体结构，可以夹带液体、有利于处理泵内凝液和微小颗粒排放，其具有卓越的液体处理能力，排气口可直接回收溶剂及一些高价值的工艺溶媒介质。
◆螺旋式夹套冷却结构：螺旋式夹套具有优良的冷却效果，运行温度低，独特的夹套水冷结构，出口温度降至符合或接近T4要求。
◆密封结构可靠耐用：采用机械密封和唇形密封，可根据工况要求在机械密封前设立空气和氮气气障保护，防止粉尘及其他杂志进入泵内。
◆IEC法兰：C法兰设计便于安装，降低了噪音解决了联轴器校准问题，增大的螺纹防止变形和振动。
 
等螺距螺杆真空泵的特点
● 无内压缩，蒸汽不易于在泵内被压缩冷凝
● 在粗真空时亦能保持最高的抽气速率

变螺距螺杆真空泵的特点
● 较低的排气温度
● 存在内压缩，较低的能耗 

应用 :
◆化工制药    —   蒸馏、干燥、浓缩、溶媒回收、脱水、分子蒸馏
◆食品        —   冷冻干燥、包装
◆电子        —   化学汽相淀积，干法刻蚀，光伏
◆工业炉      —   焊接、烘箱、烧结，热处理
◆航空、航天  —   风洞、空间模拟试验

		DVS-150	DVS-300	DVS-450	DVS-600
最大抽速	m3/h	150	300	450	600
转速	rpm	2900	2900	2900	2900
极限真空度	Pa	20	10	10	10
最大排气背压	Bar.g	0.3	0.3	0.3	0.3
电机功率	Kw	4/5.5	7.5/11	15	18.5
进气口尺寸	DN	40	50	80	100
排气口尺寸	DN	32	40	50	65
冷却水接口尺寸		G3/8	G1/2	G1/2	1/2
冷却水用量	L/min	10	20	30	35
泵体重量	Kg	260	380	560	630
密封形式
进气端		双联唇形密封
排气端		唇形密封+机械密封
驱动端		机械密封+唇形密封
材质
泵体		HT-250(哈氏合金涂层)
端盖		HT-250
转子		QT-500(哈氏合金涂层)
轴		QT-500与转子整体成型加工