Fire tube type heat exchanger

Abstract

The invention discloses a fire tube type heat exchanger, which comprises a shell and a fire tube, wherein the fire tube comprises a straight tube part and a bending part, the top end of the straight tube part is communicated with the top of the bending part, the bottom end of the straight tube part is provided with an inlet, the bottom end of the bending part is provided with an outlet, the inlet is located at the bottom of the shell, and the outlet is located in the side part of the shell. The temperature of the straight tube part of the fire tube type heat exchanger is higher, flue gas can be condensed only at the bending part, and the condensed water can flow in the bending part from top to bottom, so that the heat exchanger runs without noise, the situation that the condensed water stays in the fire tube for long time to cause corrosion to the fire tube can be prevented, the backflowing of the condensed water can be prevented, and the service life of the fire tube can be prolonged. The outlet of the fire tube is located in the side part of the shell, and the fire tube can be entirely located below the heat exchange medium liquid level, so that the temperature of discharged flue gas can be reduced, the energy utilization rate can be improved, corrosion to the fire tube caused by partial explosion to the air can be avoided, the service life of the fire tube can be prolonged and further the service life of the heat exchanger can be prolonged.

Description

technical field [0001] The invention relates to a heat exchanger, in particular to a fire tube heat exchanger. Background technique [0002] The heat exchangers in existing steam generators, water boilers and other equipment are generally fire tube heat exchangers (such as figure 1 As shown), the fire tube 2 extends upwards from the bottom of the heat exchanger shell 1 in a stepped manner, the inlet 23 of the fire tube 2 is located at the bottom of the heat exchanger, and the outlet 24 is located at the top of the heat exchanger. [0003] The heat exchanger generally obtains the heat source by burning natural gas or liquefied petroleum gas through fire exhaust, and the combustion of natural gas or liquefied petroleum gas will produce a large amount of water vapor (1Nm 3 Complete combustion of natural gas produces 1.666kg of water, 1Nm 3 Complete combustion of liquefied petroleum gas produces 3.75kg of water), which condenses into water when the fire tube 2 is running. Sin...

AI Technical Summary

Problems solved by technology

The fire tube 2 is generally made of stainless steel. Affected by the heat of argon arc welding, the passivation film on the surface of the stainless steel and the internal structure of the metal are damaged. Since the part of the fire tube 2 above the liquid level in the heat exchanger is affected by water vapor for a long time, it will Severely corroded, shortening the service life of the fire tube 2

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