The principle of steam jet pump and steam injector

Description of steam injector:

A steam injector is a device that is powered by steam and is needed in modern engineering. It does not require electricity, has no moving or rotating parts, is simple in system, and works reliably, so it is used.

Steam injector structure - Introduction:

The steam injector structure mainly consists of two parts:

1. Spray nozzle: High pressure steam forms a high-speed jet through the spray nozzle. The shape and size of thespray nozzle are calculated based on the quality of the steam (superheated or saturated steam) and the pressure drop of the steam at the spray nozzle. When the pressure drop of the spray nozzle is above 45.5% of the initial pressure of the superheated steam. The saturated vapor is above 42.3% of the initial pressure. The nozzle is made into a Laval nozzle, otherwise the nozzle is conical, and the material used is 1Cr18Ni9Ti.

2. Steam injector - combined -: After the two streams of high and low pressure steam are uniformly combined in this pipe, the speed is reduced and the pressure is increased. So - there -, -, and the last three - have different effects. The shape is different, and its size (diameter and degree) is designed based on the total flow rate to ultimately synthesize the required pressure of steam. The component connecting the two is called a steam chamber, which maintains a reasonable distance between the two components and has a certain space. The material of the steam injector is made of 1cr18Ni9Ti or 20 # - carbon steel.

Equipment operation:

Steam jet water heaters and vacuum heaters have different operating requirements, but the temperature of the booster is high and the pipes should be warmed up. At the beginning, a small amount of low-pressure steam enters the steam chamber of the jet booster and is discharged into the steam supply pipe for heating. According to the factory regulations, the pipes are heated in stages. As the low-pressure steam increases, the high-pressure steam valve is gradually opened to form a supply pressure at the outlet, which is adapted to the steam consumption.

Steam injector installation:

1. This equipment is installed in pipelines and high-pressure steam pipes. The low-pressure steam pipe and heating pipe are respectively connected to the flange of this component, and the flange is from the Ministry of Chemical Industry.

2. Vacuum type steam injectors (such as shaft seal air extractors) can be fixed on walls, columns, and then connected to relevant pipes due to their smaller size.

3. Equipment should be arranged from top to bottom or horizontally in the direction of steam outlet, and avoid being arranged from bottom to top.

Material of steam injector -:

Steam injectors are made of materials such as carbon steel, stainless steel, and ordinary cast iron. They are stable, easy to install, and do not require high-level installation. They can be installed on flat ground. Each type of steam injector can be vacuumed by equipped with corresponding centrifugal water pumps, and can be used in parallel.

Scope of use of steam injectors:

There are the following types of steam injectors:

1. Steam injector booster type:

High temperature and high pressure steam with high energy is attracted by the high-speed jet of the nozzle to produce low-pressure steam at the required temperature and pressure for the synthesis process. This is a more energy-efficient form required by the process (compared to temperature and pressure reducers), and it is also more convenient. There is also a type of equipment called a secondary steam recovery device.

2. Steam jet hot water type:

By using steam jet suction, a certain amount of cold water is heated to the desired temperature and delivered to the desired location, which can be used for heating and domestic water.

3. Steam injector vacuum type:

By steam jet, the air inside the container is extracted to provide a certain vacuum. Like the steam turbine shaft seal extractor, it prevents the steam turbine from flowing outward and recovers heat and working fluid. For example, using a type of circulating water pump to suction and vacuum to attract low-level water flow.

4. Steam ejector:

The steam jet air extractor is used on the steam turbine shaft seal air recovery device, thereby eliminating the loss of steam at the end of the steam turbine shaft seal, improving the thermal economy of the unit, improving the on-site environment, and preventing air from entering the bearing lubricating oil due to excessive time of the shaft seal air. This is an important measure to prevent oil water content and high shaft seal temperature-- The thermal design uses a steam jet extractor for the sealing steam condenser, reducing the loss of steam in the turbine shaft seal. It also uses the heat of the gas to heat the condensate, recover heat and working fluid, improve the thermal economy of the unit, and prevent oil water ingress and bearing high temperature accidents caused by excessive gas from the shaft seal entering the bearing lubricating oil.. Work principle: Working steam enters the nozzle, expands and accelerates into the mixing chamber, forming a high degree of vacuum in the mixing chamber, which extracts the gas and vapor mixture from the condenser. After mixing, it enters the expansion tube, where the pressure is slightly higher than the pressure. After condensing through the cooler, some steam condenses into hydrophobic water and returns to the condenser, with a small amount of gas and vapor mixture discharged into the gas. The steam jet extractor has a low extraction rate, but its structure is simple, and it can recover the heat of working steam and condensed water, so it is applied.

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