Zj-70 0.75kw 70L/S Roots Vacuum Pump

• After-sales Service: Online Video Instruction
• Warranty: 1 Year
• Oil or Not: Oil Free
• Structure: Rotary Vacuum Pump
• Nominal Pumping Speed(50Hz): 70 L/S
• Ultimate Pressure: 0.06 PA
• Model NO.: ZJ-70
• Max. Allowable Pressure Differernce: 6 Kpa
• Nominal Motor Speed(50Hz): 2780 Rpm
• Nominal Motor Rating(50Hz): 1.5 Kw
• Suction Connection Size: 80 mm
• Discharge Connection Size: 50 mm
• Weight Approx.: 87 Kg
• Transport Package: Wooden Box or Per Customer Requirements
• Trademark: Hengxi
• Origin: China
• HS Code: 8414100090
• Production Capacity: 1000pieces/Year

Product Description

 

Working principle

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 two 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 two 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 two 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 one end of the gearbox due to heat during operation.
 

The four 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 two (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.
 

 

Product Parameters

Model	Pumping speed (L/S)	Ultimate pressure (Pa)	Max. pressure difference (Pa)	Motor speed (rpm)	Motor Power (kw)	Size(mm)		Weight (kg)
						Inlet	Outlet
ZJ-30	30	6xl0^-2	8000	2770	0.75	50	40	66
ZJP-30		5xl0^-2						75
ZJ-70	70	6xl0^-2	6000	2780	1.5	80	50	87
ZJP-70		5xl0^-2						100
ZJ-150	150	6xl0^-2	6000	2900	3	100	100	198
ZJP-150		5xl0^-2						215
ZJ-300	300	6xl0^-2	5000	1450	4	150	150	490
ZJP-300		5xl0^-2						480
ZJ-600	600	6xl0^-2	4000	2900	5.5	150	150	490
ZJP-600		5xl0^-2						503
ZJ-1200	1200	6xl0^-2	3000	1450	11	300	300	1550
ZJP-1200		5xl0^-2						1580
ZJ-2500	2500	5xl0^-2	3000	2900	18.5	300	300	1620

 

Remark:
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.
 

Pressure diagram

 

 

Dimension

 

FAQ

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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