Device for prolonging operation cycle of lean solvent washing water heat exchanger

Abstract

The utility model belongs to the technical field of styrene extraction, and discloses a device for prolonging the operation cycle of a lean solvent washing water heat exchanger. Comprising a solvent recovery tower reflux tank water bag (2), a solvent recovery tower water pump (3), a lean solvent washing water heat exchanger (4), a raffinate oil adding flowmeter (5), a raffinate oil extraction flowmeter (6), an extraction distillation tower water pump (7), an extraction distillation tower reflux pump (8), an extraction tower reflux tank (9) and an extraction tower reflux tank water bag (10). The raffinate oil is introduced into the washing water, so that the concentration of styrene is reduced, the styrene is not easy to polymerize after being diluted to below 5%, and the harm that the styrene polymerizes to block a heat exchanger is eliminated; and the gathered oil phase is led out to a reflux tank of the extraction tower through an exhaust port where the oil phase is easy to gather at a high point of the heat exchanger, so that the risk that the styrene gathers in the heat exchanger is further reduced.

Description

Technical Field

[0001] This utility model belongs to the field of styrene extraction technology, and in particular relates to a device for extending the operating cycle of a lean solvent water washing water heat exchanger. Background Technology

[0002] The original design of the styrene extraction unit was a lean solvent wash water heat exchanger (the tube side carries the high-temperature medium lean solvent, and the shell side carries the low-temperature medium wash water). During long-term operation, the small amount of styrene carried in the wash water inside the heat exchanger shell tends to accumulate at the top of the heat exchanger, causing styrene polymerization and clogging of the heat exchanger, affecting the heat exchange effect. It is necessary to shut down the unit for maintenance and cleaning. The start-up and shutdown of the unit result in the waste of materials and energy. Utility Model Content

[0003] The technical problem this invention aims to solve is the problem of heat exchangers in styrene extraction devices being prone to clogging.

[0004] To solve the above-mentioned technical problems, the specific technical solution of this utility model is as follows:

[0005] An apparatus for extending the operating cycle of a lean solvent wash water heat exchanger includes a solvent recovery tower reflux tank water tank 2, a solvent recovery tower water pump 3, a lean solvent wash water heat exchanger 4, a residual oil inlet flow meter 5, a residual oil outlet flow meter 6, an extraction distillation tower water pump 7, an extraction distillation tower reflux pump 8, an extraction tower reflux tank 9, and an extraction tower reflux tank water tank 10.

[0006] The outlet of the solvent recovery tower reflux tank water tank 2 is connected to the inlet of the solvent recovery tower water pump 3. The outlet of the extraction tower reflux tank water tank 10 is connected to the inlet of the extraction distillation tower water pump 7. The outlet of the solvent recovery tower water pump 3 is connected to the inlet of the lean solvent wash water heat exchanger 4. The outlet of the extraction distillation tower water pump 7 is connected to the inlet of the lean solvent wash water heat exchanger 4. The outlet of the extraction tower reflux tank 9 is connected to the inlet of the extraction distillation tower reflux pump 8. The outlet of the extraction distillation tower reflux pump 8 is connected to the inlet of the residual oil inlet flow meter 5. The outlet of the residual oil inlet flow meter 5 is connected to the inlet of the lean solvent wash water heat exchanger 4. The exhaust port of the lean solvent wash water heat exchanger 4 is connected to the inlet of the residual oil collection flow meter 6. The outlet of the residual oil collection flow meter 6 is connected to the outlet of the extraction distillation tower reflux pump 8.

[0007] The solvent recovery tower reflux tank water tank 2 is installed on the solvent recovery tower reflux tank 1.

[0008] The flow rate of the washing water pump 3 in the solvent recovery tower is approximately 1.5 t / h.

[0009] The device has the following advantages: the device reduces the concentration of styrene by introducing the raffinate into the washing water, and the styrene is not easy to polymerize after being diluted to below 5%, thereby eliminating the harm of styrene polymerization to block the heat exchanger; and the accumulated oil phase is introduced out of the heat exchanger to the extraction column reflux tank through the exhaust port where the oil phase is easy to accumulate, thereby further reducing the risk of styrene accumulation in the heat exchanger. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 The device structure diagram for prolonging the operation cycle of the lean solvent washing water heat exchanger of the utility model. DETAILED DESCRIPTION

[0011] In order to better understand the purpose, structure and function of the utility model, the utility model will be described in further detail below in combination with the drawings.

[0012] As Figure 1 shown, the device for prolonging the operation cycle of the lean solvent washing water heat exchanger of the utility model comprises a solvent recovery column reflux tank 1, a solvent recovery column water package 2, a solvent recovery tower water pump 3, a lean solvent washing water heat exchanger 4, a raffinate addition flowmeter 5, a raffinate production flowmeter 6, an extraction distillation column water pump 7, an extraction distillation column reflux pump 8, an extraction column reflux tank 9 and an extraction column reflux tank water package 10.

[0013] The outlet of the solvent recovery column reflux tank water package 2 is in communication with the inlet of the solvent recovery tower water pump 3, the outlet of the extraction column reflux tank water package 10 is connected with the inlet of the extraction distillation column water pump 7, the outlet of the solvent recovery tower water pump 3 is connected with the inlet of the lean solvent washing water heat exchanger 4, the outlet of the extraction distillation column water pump 7 is connected with the inlet of the lean solvent washing water heat exchanger 4, the outlet of the extraction column reflux tank 9 is connected with the inlet of the extraction distillation column reflux pump 8, the outlet of the extraction distillation column reflux pump 8 is connected with the inlet of the raffinate addition flowmeter 5, the outlet of the raffinate addition flowmeter 5 is connected with the inlet of the lean solvent washing water heat exchanger 4, the exhaust port of the lean solvent washing water heat exchanger 4 is connected with the inlet of the raffinate production flowmeter 6, and the outlet of the raffinate production flowmeter 6 is connected with the outlet of the extraction distillation column reflux pump 8.

[0014] As can be seen from the above, the water washing water is combined after flowing from the solvent recovery backflow tank water package 2 and the extraction column backflow tank water package 10, and then enters the lean solvent water washing water heat exchanger 4. Since the medium of the solvent recovery backflow tank 1 is styrene, the insufficient settling time of the lower end solvent recovery backflow tank water package 2 causes the water washing water pumped by the solvent recovery column water pump 3 to entrain a certain amount of styrene (about 150 PPM of oil in the analysis water). Since the styrene entrained in the water washing water is gathered at the heat exchanger head with a lower flow rate after passing through the multiple baffle plates of the lean solvent water washing water heat exchanger 4, the styrene is aggregated and polymerized at high temperature to cause blockage. In this embodiment, a certain amount of raffinate oil from the outlet of the stripping distillation column backflow pump 8 is added before the water washing water enters the lean solvent water washing water heat exchanger 4 to reduce the concentration of the styrene aggregated at the top of the heat exchanger. When the concentration of the styrene is less than 5%, the styrene polymerization is greatly reduced. The flow rate of the water washing water pumped by the solvent recovery column water pump 3 is about 1.5 t / h, and the calculation of the entrained styrene concentration of 0.225 kg / h is greater than or equal to 4.88 kg / h. However, the actual operation suggests that the dilution is to 3%, about 8.28 kg / h. At the same time, the diluted styrene and raffinate oil mixture is mixed at the position where the oil phase is easily aggregated at the top of the lean solvent water washing water heat exchanger 4, and then is sent out of the device area through the outlet of the raffinate oil extraction flow meter 6 and the outlet of the stripping distillation column backflow pump 8, and the discharge amount is the sum of the amount of the entrained styrene and the amount of the added raffinate oil.

[0015] Although the embodiments of the present application are described in combination with the drawings, a number of modifications and improvements can be made by those skilled in the art without departing from the principles of the present application, and these should be considered to fall within the scope of protection of the present application.

Claims

1. A device for extending the operating cycle of a lean solvent water scrubber water heater, characterized in that, The solvent recovery column reflux tank water tank (2), solvent recovery column water pump (3), lean solvent water washing water heat exchanger (4), raffinate oil adding flowmeter (5), raffinate oil production flowmeter (6), extraction distillation column water pump (7), extraction distillation column reflux pump (8), extraction column reflux tank (9) and extraction column reflux tank water tank (10) are included. The solvent recovery column reflux tank water tank (2) outlet is connected with the solvent recovery column water pump (3) inlet, the extraction column reflux tank water tank (10) outlet is connected with the extraction distillation column water pump (7) inlet, the solvent recovery column water pump (3) outlet is connected with the lean solvent water washing water heat exchanger (4) inlet, the extraction distillation column water pump (7) outlet is connected with the lean solvent water washing water heat exchanger (4) inlet, the extraction column reflux tank (9) outlet is connected with the extraction distillation column reflux pump (8) inlet, the extraction distillation column reflux pump (8) outlet is connected with the raffinate oil adding flowmeter (5) inlet, the raffinate oil adding flowmeter (5) outlet is connected with the lean solvent water washing water heat exchanger (4) inlet, the lean solvent water washing water heat exchanger (4) exhaust port is connected with the raffinate oil production flowmeter (6) inlet, and the raffinate oil production flowmeter (6) outlet is connected with the extraction distillation column reflux pump (8) outlet.

2. The apparatus for extending the operating cycle of a lean solvent water scrubber water heat exchanger of claim 1, wherein, The solvent recovery column reflux tank water tank (2) is arranged on the solvent recovery column reflux tank (1).

3. The apparatus of claim 1, wherein the apparatus is configured to extend the operating cycle of the lean solvent water scrubber water heat exchanger by, The solvent recovery column water pump (3) pumps out 1.5 t / h of water washing water.

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