CN202048562U - Improved water supply system of electric-furnace exhaust heat boiler - Google Patents

Abstract

The utility model discloses an improved electric furnace waste heat boiler water supply system, which comprises an economizer, a preheater, a steam drum, a deaerator, a pump group and a soft water tank, and the outlet pipe of the soft water tank passes through the soft water pump group and the electric valve in sequence It is connected to the water inlet of the deaerator, and the outlet pipe of the deaerator is connected to the steam drum through the front pump group, the feed water pump group, the electric valve, the preheater, the economizer, and the check valve. A bypass pipe equipped with an electric valve is connected to the water pipe between the coal burners, and the other end of the bypass pipe is connected to the water inlet of the deaerator. The front pump and feed water pump of the utility model are always working, and the preheater and the economizer are in a continuous water supply state during the high-temperature smelting process, which improves the service life of the preheater and the economizer, and ensures the normal operation of the equipment; the deoxygenation effect is good, Avoid frequent start-up of the pre-pump and feed water pump, and increase the service life of the motor and water pump; after improvement, the internal circulation absorbs the waste heat of the flue gas for heating, and the steam heating pipeline is abolished, further reducing the temperature of the flue gas.

Description

Improved Water Supply System for Electric Furnace Waste Heat Boiler

technical field

The utility model relates to an improved electric furnace waste heat boiler water supply system.

Background technique

The main function of the electric furnace waste heat boiler system is to recover the waste heat of the electric furnace flue gas and generate saturated steam for external supply, which can efficiently cool the high-temperature flue gas, and at the same time fully convert the waste heat of the flue gas into steam, turning waste into treasure and recycling. The system consists of three parts: water supply system, heat pipe steam generator and heat accumulator. The water supply system is an important part of the waste heat boiler. 1. The softened water heating part is composed of a softened water tank, two softened water pumps, a set of softened water preheaters and a thermal deaerator. The main function is to preheat soft water and prepare deoxygenated water for the system. If the water level of the deaerator is low, the electric valve is opened at the same time, and the water in the softened water tank is pumped into the soft water preheater by the soft water pump, and after being heated by the preheater and steam drum, it enters the thermal deaerator for deoxygenation and is ready for use. If the water level of the deaerator is high, the soft water pump stops working. The electric valve is closed; 2. The feed water heating part is composed of two feed water pumps, two front pumps, a set of horizontal economizers and steam drums. The main function is to heat the feed water and replenish water to the steam drum to ensure that the liquid level is a constant value. When the water level of the steam drum is low, the electric valve is opened, and the water in the deaerator is pumped into the economizer through the front pump and the feed water pump in turn to absorb the waste heat of the flue gas, heat it, and finally enter the steam drum to complete the water replenishment of the steam drum. The feed water pump adopts frequency conversion control, and jointly controls the feed water flow with the electric valve. When the water level of the steam drum is normal, the front pump and feed water pump stop working, and the electric valve is closed.       

There are three main defects in the operation of the equipment: 1. During the smelting process of the electric furnace, when the water level of the deaerator is normal, the soft water pump does not work, and the preheater is in a state of water shortage and dry burning; when the water level of the steam drum is normal, the front pump, The feed water pump is not working, and the economizer is in a state of water shortage and dry burning, which seriously affects the service life of the preheater and economizer (it needs to be replaced every six months before); 2. Due to discontinuous heating of soft water, the temperature of the oxygen removal head is less than 95°C, the oxygen removal effect cannot be achieved (the oxygen removal head temperature must be ≥104°C to remove oxygen); 3. The medium temperature in the front pump and the feed water pump is high, and the opening is frequent, and the accident rate is high.

Contents of the invention

The purpose of this utility model is to provide an improved electric furnace waste heat boiler water supply system, which has a simple and reasonable structure, can effectively eliminate three main defects in the existing water supply system, and ensure normal production.

The purpose of this utility model is achieved in this way. An improved electric furnace waste heat boiler water supply system includes an economizer, a preheater, a steam drum, a deaerator, a pump unit, and a soft water tank. The water pump group and the electric valve are connected to the water inlet of the deaerator, and the outlet pipe of the deaerator is connected to the steam drum through the front pump group, the feed water pump group, the electric valve, the preheater, the economizer, and the check valve in sequence. A bypass pipe equipped with an electric valve is connected to the water pipe between the check valve and the economizer, and the other end of the bypass pipe is connected to the water inlet of the deaerator.

The front pump and feed water pump of the utility model are always working, and the preheater and the economizer are in a continuous water supply state during the high-temperature smelting process, which improves the service life of the preheater and the economizer and ensures the normal operation of the equipment; after the transformation, the deaerator The water in the tank is always in a state of circulating heating, and the temperature of the oxygen removal head is greater than 104°C to achieve the effect of oxygen removal and avoid oxygen corrosion to the steam drum, evaporator and its pipeline; avoid frequent start-up of the pre-pump and feed water pump, and improve the motor and The service life of the water pump; after improvement, the internal circulation absorbs the waste heat of the flue gas to heat, abolishes the steam heating pipeline, saves energy, and further reduces the temperature of the flue gas.

Description of drawings

The utility model will be described in further detail below in conjunction with the accompanying drawings.

Fig. 1 is a schematic diagram of the connection structure of the present invention.

Detailed ways

An improved electric furnace waste heat boiler water supply system, as shown in Figure 1, includes an economizer 2, a preheater 3, a steam drum 1, a deaerator 9, a pump unit, and a soft water tank 6, and the outlet pipes of the soft water tank 6 are sequentially It is connected with the water inlet of the deaerator 9 through the soft water pump group 7 and the electric valve 8 . The outlet pipe of the deaerator 9 is connected to the steam drum 1 through the pre-pump group 10, the feed water pump group 5, the electric valve 4, the preheater 3, the economizer 2, and the check valve. A bypass pipe equipped with an electric valve 11 is connected to the water pipe between the devices 2, and the other end of the bypass pipe links to each other with the deaerator 9 water inlets.

The purpose of the improvement of the utility model is to improve the service life of the preheater and the economizer, increase the temperature of the oxygen removal head, and achieve the oxygen removal effect under the condition of meeting the production demand. By connecting the preheater 3 and the economizer 2 in series, the softened water in the softened water tank 6 is pumped directly into the thermal deaerator 9 without heating by the softened water pump 7 and then used for standby after deaeration, between the steam drum 1 and the deaerator 9 The original steam heating pipeline is removed; a bypass pipeline is installed between the water supply pipeline between the economizer 2 and the steam drum 1 and the deaerator 9. During the normal smelting process of the electric furnace, the front pump 10 and the feed water pump 5 are always running. The heater 3 and the economizer 2 absorb the waste heat of the flue gas and heat it and finally enter the steam drum 1 to complete the water replenishment of the steam drum. When the water level is normal and does not need to replenish water, the electric valve 11 is opened, and the deoxygenated water is returned to the deaerator 9 through a bypass to realize internal circulation heating.

Claims (1)

1. An improved electric furnace waste heat boiler water supply system, including an economizer, a preheater, a steam drum, a deaerator, a pump unit and a soft water tank, is characterized in that: the outlet pipe of the soft water tank passes through the soft water pump unit and the electric The valve is connected to the water inlet of the deaerator, and the outlet pipe of the deaerator is connected to the steam drum through the front pump group, the feed water pump group, the electric valve, the preheater, the economizer, and the check valve. A bypass pipe equipped with an electric valve is connected to the water pipe between the economizers, and the other end of the bypass pipe is connected to the water inlet of the deaerator.