Roots vacuum pump, also known as mechanical booster pump, is a rotary positive displacement vacuum pump. The schematic structure of the Roots vacuum pump is shown in Figure on the left. There are 2 figure-8 rotors in the pump chamber, which are installed on a pair of shafts in parallel, and are driven by a pair of synchronous gear. The rotor and the rotor, the rotors and the pump chamber maintain a certain gap and do not contact each other, so the friction loss during operation is very small, the friction power consumption is extremely small, and high-speed operation can be achieved.
Figure below shows the internal structure of the Roots vacuum pump. The 2 rotors of the pump are supported in the rolling bearings on the end covers on both sides of the pump chamber, and rely on a pair of adjustable synchronous gears to keep the 2 rotors rotating at high speed. A certain mutual position, and the end face gap between the rotor and the end cover is guaranteed by the special structure of the fixed end (closer to the motor side), so that the pump can only expand to 1 end of the gearbox due to heat during operation.
The 4 sets of PTFE piston ring seals in the end caps on both sides can prevent the lubricating oil in the oil tanks on both sides from entering the pump chamber, and the balanced mechanical seal at the outlet shaft can prevent the atmosphere from leaking into the pump chamber.
The cooling method of the pump is usually air cooling. If the pump is used for working in the high pressure range, it is recommended to select a pump with a water cooling structure. The power of the motor is transmitted to the driving shaft through the coupling, and then the driven shaft is driven to rotate by the driving shaft through the synchronous gear. ZJ series Roots vacuum pumps are of horizontal structure, and the pump is directly connected with the motor by means of a coupling. But the pump with special requirements can adopt the V-belt drive structure.
ZJP type Roots vacuum pump with bypass valve is a derivative product of ZJ type Roots vacuum pump. The pumping principle is the same as that of ZJ type pump. It also uses a pair of 8-shaped rotors to maintain a certain gap in the pump casing. It rotates to generate suction and exhaust. The difference is that the inlet and exhaust ports of the ZJP type Roots vacuum pump with bypass valve are connected, and a gravity valve is installed vertically on the channel of the 2 (see Figure on the left). When the force on the valve caused by the pressure difference between the intake port and the exhaust port exceeds the weight of the valve itself, it will automatically open. This value of pressure difference which cause the valve to open is the highest differential pressure at which the pump can operate reliably. Therefore, this valve is actually an overload automatic protection valve, and it is also the biggest advantage of ZJP type Roots vacuum pump. Theoretically, the ZJP Roots pump can be started synchronously with the backing pump under atmospheric pressure to pump the system. If the system volume is large, the bypass valve of the ZJP Roots pump is open for a long time, and the pump’s effective pumping speed is small, so it is not economical to start the ZJP type Roots pump at atmospheric pressure for large systems. It is recommended to start the ZJP Roots vacuum pump when the backing pump reaches a certain pressure.
The advantage of the Roots vacuum pump is that it has a higher pumping speed at a lower inlet pressure, but it cannot be used alone. There must be a backing vacuum pump in series, and the pressure in the system is pumped by the backing vacuum pump to an allowable starting pressure of the Roots vacuum pump before it is started(See figure on the left). In general, the Roots vacuum pump is not allowed to work under high pressure difference, otherwise it will be overloaded, overheated and damaged, so the backing vacuum pump must be selected reasonably, and the necessary protective equipment must be installed.
The backing vacuum pump is generally an oil-sealed mechanical pump, but if the ultimate pressure requirement is not high, other forms of rough vacuum pump can be used as the backing pump, especially when the gas containing a large amount of water vapor is extracted, the dry screw vacuum pump is recommended as the backing pump.
|Pumping speed (L/S)
|Ultimate pressure (Pa)
|Max. pressure difference (Pa)
|Motor speed (rpm)
|Motor Power (kw)
1. The pumping speed refers to the maximum pumping speed measured when the inlet pressure of the Roots vacuum pump is in the range of 67 Pa ~ 2.67 Pa under the condition that the recommended backing pump is used.
2. The ultimate pressure refers to the stable minimum air pressure measured at the inlet of the pump with a vacuum gauge after fully operation without any additional container, the pump port is closed and no intake air is provided under the condition that the recommended backing pump is used.
3. The performances in the above table are obtained under the condition that the recommended backing pump is used. Users can choose different backing vacuum pumps according to different situations, but their main performance data will vary.
Q: What information should I offer for an inquiry?
A: You can inquire based on the model directly, but it is always recommended that you contact us so that we can help you to check if the pump is the most appropriate for your application.
Q: Can you make a customized vacuum pump?
A: Yes, we can do some special designs to meet customer applications. Such as customized sealing systems, speical surface treatment can be applied for roots vacuum pump and screw vacuum pump. Please contact us if you have special requirements.
Q: I have problems with our vacuum pumps or vacuum systems, can you offer some help?
A: We have application and design engineers with more than 30 years of experience in vacuum applications in different industries and help a lot of customers resolve their problems, such as leakage issues, energy-saving solutions, more environment-friendly vacuum systems, etc. Please contact us and we’ll be very happy if we can offer any help to your vacuum system.
Q: Can you design and make customized vacuum systems?
A: Yes, we are good for this.
Q: What is your MOQ?
A: 1 piece or 1 set.
Q: How about your delivery time?
A: 5-10 working days for the standard vacuum pump if the quantity is below 20 pieces, 20-30 working days for the conventional vacuum system with less than 5 sets. For more quantity or special requirements, please contact us to check the lead time.
Q: What are your payment terms?
A: By T/T, 50% advance payment/deposit and 50% paid before shipment.
Q: How about the warranty?
A: We offer 1-year warranty (except for the wearing parts).
Q: How about the service?
A: We offer remote video technical support. We can send the service engineer to the site for some special requirements.
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|Nominal Motor Rating(50Hz):
What Is the Role of Vacuum Pumps in Semiconductor Manufacturing?
Vacuum pumps play a critical role in semiconductor manufacturing processes. Here’s a detailed explanation:
Semiconductor manufacturing involves the production of integrated circuits (ICs) and other semiconductor devices used in various electronic applications. Vacuum pumps are used extensively throughout the semiconductor manufacturing process to create and maintain the required vacuum conditions for specific manufacturing steps.
Here are some key roles of vacuum pumps in semiconductor manufacturing:
1. Deposition Processes: Vacuum pumps are used in deposition processes such as physical vapor deposition (PVD) and chemical vapor deposition (CVD). These processes involve depositing thin films of materials onto semiconductor wafers to create various layers and patterns. Vacuum pumps help create a low-pressure environment necessary for precise control of the deposition process, ensuring uniform and high-quality film formation.
2. Etching and Cleaning: Vacuum pumps are utilized in etching and cleaning processes, which involve the removal of specific layers or contaminants from semiconductor wafers. Dry etching techniques, such as plasma etching and reactive ion etching, require a vacuum environment to facilitate the ionization and removal of material. Vacuum pumps aid in creating the necessary low-pressure conditions for efficient etching and cleaning processes.
3. Ion Implantation: Ion implantation is a process used to introduce impurities into specific regions of a semiconductor wafer to modify its electrical properties. Vacuum pumps are used to evacuate the ion implantation chamber, creating the required vacuum environment for accurate and controlled ion beam acceleration and implantation.
4. Wafer Handling and Transfer: Vacuum pumps are employed in wafer handling and transfer systems. These systems utilize vacuum suction to securely hold and manipulate semiconductor wafers during various manufacturing steps, such as loading and unloading from process chambers, robotic transfer between tools, and wafer alignment.
5. Load Lock Systems: Load lock systems are used to transfer semiconductor wafers between atmospheric conditions and the vacuum environment of process chambers. Vacuum pumps are integral components of load lock systems, creating and maintaining the vacuum conditions necessary for wafer transfer while minimizing contamination risks.
6. Metrology and Inspection: Vacuum pumps are utilized in metrology and inspection tools used for characterizing semiconductor devices. These tools, such as scanning electron microscopes (SEMs) and focused ion beam (FIB) systems, often operate in a vacuum environment to enable high-resolution imaging and accurate analysis of semiconductor structures and defects.
7. Leak Detection: Vacuum pumps are employed in leak detection systems to identify and locate leaks in vacuum chambers, process lines, and other components. These systems rely on vacuum pumps to evacuate the system and then monitor for any pressure rise, indicating the presence of leaks.
8. Cleanroom Environment Control: Semiconductor manufacturing facilities maintain cleanroom environments to prevent contamination during the fabrication process. Vacuum pumps are used in the design and operation of the cleanroom ventilation and filtration systems, helping to maintain the required air cleanliness levels by removing particulates and maintaining controlled air pressure differentials.
Vacuum pumps used in semiconductor manufacturing processes are often specialized to meet the stringent requirements of the industry. They need to provide high vacuum levels, precise control, low contamination levels, and reliability for continuous operation.
Overall, vacuum pumps are indispensable in semiconductor manufacturing, enabling the creation of the necessary vacuum conditions for various processes, ensuring the production of high-quality semiconductor devices.
Can Vacuum Pumps Be Used for Soil and Groundwater Remediation?
Vacuum pumps are indeed widely used for soil and groundwater remediation. Here’s a detailed explanation:
Soil and groundwater remediation refers to the process of removing contaminants from the soil and groundwater to restore environmental quality and protect human health. Vacuum pumps play a crucial role in various remediation techniques by facilitating the extraction and treatment of contaminated media. Some of the common applications of vacuum pumps in soil and groundwater remediation include:
1. Soil Vapor Extraction (SVE): Soil vapor extraction is a widely used remediation technique for volatile contaminants present in the subsurface. It involves the extraction of vapors from the soil by applying a vacuum to the subsurface through wells or trenches. Vacuum pumps create a pressure gradient that induces the movement of vapors towards the extraction points. The extracted vapors are then treated to remove or destroy the contaminants. Vacuum pumps play a vital role in SVE by maintaining the necessary negative pressure to enhance the volatilization and extraction of contaminants from the soil.
2. Dual-Phase Extraction (DPE): Dual-phase extraction is a remediation method used for the simultaneous extraction of both liquids (such as groundwater) and vapors (such as volatile organic compounds) from the subsurface. Vacuum pumps are utilized to create a vacuum in extraction wells or points, drawing out both the liquid and vapor phases. The extracted groundwater and vapors are then separated and treated accordingly. Vacuum pumps are essential in DPE systems for efficient and controlled extraction of both liquid and vapor-phase contaminants.
3. Groundwater Pumping and Treatment: Vacuum pumps are also employed in groundwater remediation through the process of pumping and treatment. They are used to extract contaminated groundwater from wells or recovery trenches. By creating a vacuum or negative pressure, vacuum pumps facilitate the flow of groundwater towards the extraction points. The extracted groundwater is then treated to remove or neutralize the contaminants before being discharged or re-injected into the ground. Vacuum pumps play a critical role in maintaining the required flow rates and hydraulic gradients for effective groundwater extraction and treatment.
4. Air Sparging: Air sparging is a remediation technique used to treat groundwater and soil contaminated with volatile organic compounds (VOCs). It involves the injection of air or oxygen into the subsurface to enhance the volatilization of contaminants. Vacuum pumps are utilized in air sparging systems to create a vacuum or negative pressure zone in wells or points surrounding the contaminated area. This induces the movement of air and oxygen through the soil, facilitating the release and volatilization of VOCs. Vacuum pumps are essential in air sparging by maintaining the necessary negative pressure gradient for effective contaminant removal.
5. Vacuum-Enhanced Recovery: Vacuum-enhanced recovery, also known as vacuum-enhanced extraction, is a remediation technique used to recover non-aqueous phase liquids (NAPLs) or dense non-aqueous phase liquids (DNAPLs) from the subsurface. Vacuum pumps are employed to create a vacuum or negative pressure gradient in recovery wells or trenches. This encourages the movement and extraction of NAPLs or DNAPLs towards the recovery points. Vacuum pumps facilitate the efficient recovery of these dense contaminants, which may not be easily recoverable using traditional pumping methods.
It’s important to note that different types of vacuum pumps, such as rotary vane pumps, liquid ring pumps, or air-cooled pumps, may be used in soil and groundwater remediation depending on the specific requirements of the remediation technique and the nature of the contaminants.
In summary, vacuum pumps play a vital role in various soil and groundwater remediation techniques, including soil vapor extraction, dual-phase extraction, groundwater pumping and treatment, air sparging, and vacuum-enhanced recovery. By creating and maintaining the necessary pressure differentials, vacuum pumps enable the efficient extraction, treatment, and removal of contaminants, contributing to the restoration of soil and groundwater quality.
Are There Different Types of Vacuum Pumps Available?
Yes, there are various types of vacuum pumps available, each designed to suit specific applications and operating principles. Here’s a detailed explanation:
Vacuum pumps are classified based on their operating principles, mechanisms, and the type of vacuum they can generate. Some common types of vacuum pumps include:
1. Rotary Vane Vacuum Pumps:
– Description: Rotary vane pumps are positive displacement pumps that use rotating vanes to create a vacuum. The vanes slide in and out of slots in the pump rotor, trapping and compressing gas to create suction and generate a vacuum.
– Applications: Rotary vane vacuum pumps are widely used in applications requiring moderate vacuum levels, such as laboratory vacuum systems, packaging, refrigeration, and air conditioning.
2. Diaphragm Vacuum Pumps:
– Description: Diaphragm pumps use a flexible diaphragm that moves up and down to create a vacuum. The diaphragm separates the vacuum chamber from the driving mechanism, preventing contamination and oil-free operation.
– Applications: Diaphragm vacuum pumps are commonly used in laboratories, medical equipment, analysis instruments, and applications where oil-free or chemical-resistant vacuum is required.
3. Scroll Vacuum Pumps:
– Description: Scroll pumps have two spiral-shaped scrolls—one fixed and one orbiting—which create a series of moving crescent-shaped gas pockets. As the scrolls move, gas is continuously trapped and compressed, resulting in a vacuum.
– Applications: Scroll vacuum pumps are suitable for applications requiring a clean and dry vacuum, such as analytical instruments, vacuum drying, and vacuum coating.
4. Piston Vacuum Pumps:
– Description: Piston pumps use reciprocating pistons to create a vacuum by compressing gas and then releasing it through valves. They can achieve high vacuum levels but may require lubrication.
– Applications: Piston vacuum pumps are used in applications requiring high vacuum levels, such as vacuum furnaces, freeze drying, and semiconductor manufacturing.
5. Turbo Molecular Vacuum Pumps:
– Description: Turbo pumps use high-speed rotating blades or impellers to create a molecular flow, continuously pumping gas molecules out of the system. They typically require a backing pump to operate.
– Applications: Turbo molecular pumps are used in high vacuum applications, such as semiconductor fabrication, research laboratories, and mass spectrometry.
6. Diffusion Vacuum Pumps:
– Description: Diffusion pumps rely on the diffusion of gas molecules and their subsequent removal by a high-speed jet of vapor. They operate at high vacuum levels and require a backing pump.
– Applications: Diffusion pumps are commonly used in applications requiring high vacuum levels, such as vacuum metallurgy, space simulation chambers, and particle accelerators.
7. Cryogenic Vacuum Pumps:
– Description: Cryogenic pumps use extremely low temperatures to condense and capture gas molecules, creating a vacuum. They rely on cryogenic fluids, such as liquid nitrogen or helium, for operation.
– Applications: Cryogenic vacuum pumps are used in ultra-high vacuum applications, such as particle physics research, material science, and fusion reactors.
These are just a few examples of the different types of vacuum pumps available. Each type has its advantages, limitations, and suitability for specific applications. The choice of vacuum pump depends on factors like required vacuum level, gas compatibility, reliability, cost, and the specific needs of the application.
editor by CX 2023-10-26