I. Product Applications and Features

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

High-efficiency, low-energy water-jet vacuum pumps, boasting simple structure and reliability, offer an investment cost of only one-seventh of a rotary vacuum pump, while also featuring the following advantages:

No wear on moving and stationary parts, low life consumption, suction efficiency unaffected by operating time, and long maintenance intervals.

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

3. Excellent starting performance, capable of single-pull start-up.

4. Preventing gas phase backflow 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 through exhaust due to excess velocity.

The aforementioned requirements are difficult to achieve with traditional design methods, which is also the main reason why the efficiency of vacuum pumps has been hard to improve in the past.

The new vacuum pump is designed to meet the above requirements. Structurally, it features an intake with a分流chamber as the main channel and a combination of small holes as auxiliary channels to reduce air resistance. Depending on the specific vacuum system of the unit, the pump is designed as a single-channel or multi-channel configuration. It eliminates phase bias in the gas phase 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 sections: the gas injection section, the vortex enhancement section, and the pressure increase section. This device employs a new calculation method, confirmed by comparative experiments to determine the intake chamber geometry, throat shape, throat diameter nozzle area, and the ratio of throat length to nozzle diameter, among others. Based on the capacity of different vacuum pumps, the number of channels and water pressure are selected to achieve cross-sectional area and flow velocity, ensuring high efficiency of the intake chamber. Corrosion-resistant materials are used for all vulnerable components, extending maintenance cycles.

Based on the high flow velocity at the end of the isometric throat and the non-interference characteristic between the entire throat, this type of vacuum pump is equipped with a rear-mounted vacuum pump 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 for existing units. Additionally, any required exhaust volume extraction equipment can be designed upon request.

Section II: Product Dimensions and Interface Size Diagram

Section 4: Installation of Water Jet Vacuum Pumps and Precautions

1. Two water supply methods for vacuum pumps

There are two types of 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 system. 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 system" refers to a scenario where the injection pump draws water from the circulating water intake pipe, while the drainage pipe connects to the trench. Its advantages include:

Summer can reduce water temperature by 4 to 8 degrees Celsius, which will increase vacuum by 7 to 15 mmHg.

b. The aftercooler does not affect water temperature upon installation.

c. Avoids power loss due to over-compression of exhaust gases; the drawback is the 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 the user.

2. Selection of Ingress Parameters

Selecting the low-energy, high-efficiency jet vacuum pump series and adhering to the specified water pump and motor selection will yield a low-energy, high-efficiency performance. The intake parameters (flow rate, pressure) of the jet vacuum pump are crucial for improving the internal efficiency of the jet and suction, as well as reducing energy consumption. This is because the design of the working water nozzle diameter and water pressure determines the velocity at the nozzle exit. Moreover, the velocity is related to factors such as the jet angle, nozzle throat distance, area ratio, and throat length. Inappropriately selecting the water pump-vacuum pump combination can affect the performance.

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 sturdy.

② The vacuum pump should be installed at an appropriate height, with the exhaust outlet of closed-loop vacuum pumps elevated above the water surface by more than 1.5 meters. This low-energy, high-efficiency vacuum pump, due to its relatively lower 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 submersion depth for the exhaust outlet is 250-300mm. The supplementary cooling water for the vacuum pump should be added to the pump inlet to maximize its cooling effect.

③ Open-type circulating water ejector with the outlet pipe kept as short as possible, with no more than one bend, and using large-radius bends. The horizontal pipe section should be inclined outward with an inclination greater than 3/1000 mm. A bend towards the outlet direction should be connected inside the pipe where the recirculating water exits to facilitate the discharge of the gas-water mixture.

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

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

⑥ When 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's check valve, the height of the air connecting pipe should be ≥ 11 meters.

⑦Vacuum pump air intake pipe diameter is generally the same as the condenser air outlet pipe, 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.