I. Product Applications and Features

This "High-Efficiency Low-Consumption Water Jet Vacuum Pump" is of the fifth-generation environmental protection and vibration-dampening type (noise level less than 85 decibels). It effectively reduces vibration issues during operation of older water jet vacuum pumps. This fifth-generation pump boasts an optimized water chamber分流室 structure, throat area ratio, non-standard throat groups, and water jet kinetic energy, positioning it at the forefront of domestic technology levels in performance. The unit power consumption reaches 1.5 kW/kg of gas.

High-efficiency, low-consumption jet vacuum pump, boasting simple structure and reliability, it also offers a construction investment cost seven times lower than that of a rotary vacuum pump, along with the following advantages:

No wear on moving or static parts, low life loss, suction efficiency unaffected by running time, and long maintenance intervals.

2. Achieve the most uniform contact between indoor water droplets and air.

3. Good startability, can be started with a single pull.

4. Prevent phase return in the initial section, which is difficult to achieve solely by lengthening the throat tube.

5. Achieve uniform mixing of two-phase flow in the mixing chamber with a relatively short throat, while minimizing energy loss by utilizing the excess velocity.

These requirements are difficult to achieve with traditional design methods for water-jet vacuum pumps, which is also the main reason why the efficiency of vacuum pumps has been hard to improve previously.

The new vacuum pump is designed to meet the aforementioned requirements. Structurally, it features an intake chamber with a分流室as the main passage and a combination of small holes as auxiliary passages to reduce air resistance. Depending on the specific vacuum system of the unit, the pump is designed as a single-channel or multi-channel. It eliminates phase bias flow and enhances energy exchange between two-phase particles. To strengthen the mixing process of gas-water two-phase flow in the throat, the throat structure is divided into three parts: the gas injection section, the vortex enhancement section, and the pressure increase section. This device employs a new calculation method, confirmed through comparative experiments, to determine the intake chamber's geometric structure, throat shape, throat diameter and nozzle area, and the ratio of throat length to nozzle diameter. It also selects the number of channels and water pressure based on the capacity of different vacuum pumps to achieve cross-sectional area and flow velocity, ensuring high efficiency in the intake chamber. Corrosion-resistant materials are used for all vulnerable parts to extend maintenance intervals.

Based on the high flow velocity at the end of the isometric throat and the non-interference characteristics between the entire throat, this type of vacuum pump is equipped with a rear-mounted vacuum unit at the throat outlet end, which is used to extract the condensate gas from the shaft seal heater in the steam turbine section.

This product is suitable for auxiliary equipment matching in new unit design and energy-saving retrofitting of existing units. Additionally, any required exhaust volume extraction equipment can be designed upon request.

Section II: Product Outline and Interface Size Diagram

IV. Installation and Precautions for Water Jet Vacuum Pumps

1. Two water supply methods for vacuum pumps

There are two water supply methods available for the water jet vacuum pump.

Closed-loop system

This is the traditional arrangement, placing the water jet vacuum pump above the water jet tank, with the pump-vacuum pump-tank circulation for water supply. A certain amount of make-up water should be added to control the water temperature in the jet tank during summer use.

② Open-loop circulation

"Open Loop" refers to the scenario where the suction pump for the injection water comes from the circulating water intake pipe, and the drainage pipe connects to the trench. Its advantages include:

1. During summer, water temperature can be reduced by 4 to 8 degrees Celsius, which will increase vacuum by 7 to 15 mmHg.

b. The aftercooler will not affect water temperature after installation.

c. Prevents power loss caused by over-compression of exhaust gases, but the drawback is increased consumption of circulating water.

Before placing an order with our factory, please try to determine the type of recycling method in advance. You may also entrust our factory to determine and install the design for you.

2. Selection of Inflow Parameters

Selecting the low-energy, high-efficiency jet vacuum pump from this series, along with the specified water pump and motor, ensures optimal performance. The intake parameters (flow rate, pressure) of the jet vacuum pump are crucial for enhancing the efficiency of the jet and vacuum process, as they determine the velocity at the nozzle exit. This velocity is influenced by factors such as the jet angle, nozzle throat distance, area ratio, and throat length. Inappropriately pairing the pump with the vacuum pump can affect the operational effectiveness.

3. Installation Precautions:

The installation quality of the water jet vacuum pump is closely related to its suction capacity. Mainly attention should be paid to the following aspects:

①Vacuum pump installation should be vertical, each section should be precisely centered during assembly, and the support brackets should be stable.

② The vacuum pump should be installed at an appropriate height, with the exhaust port of the pump used in closed-loop systems elevated above the water surface by more than 1.5 meters. This low-consumption, high-efficiency vacuum pump, due to its relatively smaller exhaust velocity, should not be submerged too deeply in water. Otherwise, it may affect the suction capacity during low water pressure or increased water temperature in summer. The recommended depth for the exhaust port immersion is between 250-300mm. The supplementary cooling water for the vacuum pump should be added to the pump's inlet to maximize its cooling effect.

③ Open-type circulating jet vacuum pump, with the outlet pipe as short as possible, no more than one bend, and using large-radius bends. The horizontal section should slope outward with an inclination greater than 3/1000 mm. A bend towards the outlet direction should be connected to the pipe inserted into the circulating water outlet to facilitate the discharge of the gas-water mixture.

④For vacuum pumps in closed-loop systems, during summer, it is not advisable to use bottom-mounted vacuum pumps. The structure of the water jet tank should facilitate air exhaust. These measures all contribute to lowering the water temperature in the tank.

⑤ Prior to installation, the vacuum pump body should undergo a hydrostatic test with 0.5 MPa pressure, ensuring no leakage for five minutes.

⑥When only one vacuum pump is installed per machine, the air duct does not need to be excessively high; when two vacuum pumps are installed, to prevent water from flowing back into the condenser through the emergency vacuum pump check valve, the height of the air connecting pipe should be ≥11 meters.

⑦The air intake port diameter of the vacuum pump is generally the same as the air outlet pipe of the condenser, and the length should be kept as short as possible to reduce resistance; on the pipeline,法兰 connections are not used except for valves and equipment interfaces to minimize air leakage.