KR20010048629A - A recovery method of condensable vapors using a membrane separator - Google Patents

Abstract

PURPOSE: Disclosed is a recovery method of condensable steam using membrane. CONSTITUTION: The system for recovery of condensable steam is carried out by the following steps: a feeding step of mixed steam into a compressor (1), a compressing step, a sending step of condensate into membrane (4) along to the present of trap (7), and a storage step of condensate. To separate a condensable steam from the mixed composition, the mixture passed through a compressor (1) is condensed in the condenser (2) to store in the tank (3). The rest steam from the condenser (2) is sent into the membrane system (4). The condensate in the tank (3) may be again sent into the membrane (4) by the pump (5), and the permeated steam and the condensate are recycled iteratively into the condenser (2) to recover the condensable steam as much as possible.

Description

A method for recovering condensable vapor using a separator {A RECOVERY METHOD OF CONDENSABLE VAPORS USING A MEMBRANE SEPARATOR}

The present invention relates to a method for recovering condensable vapor in the mixed vapor using a separation membrane.

Methods of recovering vapor components from mixed steam are known. U.S. Patent No. 5,236,474 discloses the removal of steam from the gas stream by removing water vapor from the gas stream by maintaining the propulsion by introducing 8 ° C of liquid water into the permeate of the separator in a countercurrent to the feed flow to remove moisture in the vapor phase through the membrane US Patent No. 5,611,842 also discloses a method for recovering steam components from the mixed steam by using the effect of lowering the partial pressure of the steam to be separated by countercurrent flow of the steam components into the permeate of the separation membrane. It is described.

Although the above methods have some advantages in simplifying the process and saving energy in removing and recovering the vapor component from the gas stream, there is a need for a method that can increase energy efficiency by adopting a more rational process. to be.

Therefore, the present invention uses the vapor permeation membrane and the countercurrent permeate flow as described in the above-mentioned US Patent Nos. 5,236,474 and 5,611,842, but in consideration of the sequence of processes not mentioned in the patent and the transfer method of permeate flow, etc. It is an object of the present invention to provide a method for recovering condensed fumes from mixed vapors that can minimize process operating management costs.

1 is a schematic process diagram showing a first embodiment for steam recovery according to the present invention.

2 is a schematic process diagram showing a second embodiment for steam recovery according to the present invention.

3 is a schematic process diagram showing a third embodiment for steam recovery according to the present invention.

FIG. 4 is a flowchart showing the process of the operation operation procedure of the embodiment shown in FIG.

<Signs for Main Parts of Drawings>

1 --- compressor 2 --- condenser

3 --- tank 4 --- separator

5 --- Pump 6, 6 ', 6 "--- Manometer

7 --- Trap a --- 1st valve

b --- second valve c --- third valve

The present invention,

(a) feeding the mixed steam to the compressor,

(b) compressing the mixed vapor in a compressor,

(c) condensing the compressed steam in a condenser, sending the condensate to the tank and sending the uncondensed vapor to the separator.

(d) a method for recovering condensable vapor components using a separator consisting of repeating sending the vapor separated from the separator through the condenser and back to step (a).

In addition, the present invention,

(a) feeding the mixed steam to the compressor,

(b) compressing the mixed vapor in a compressor,

(c) condensing the compressed steam in a condenser, sending the condensate to the tank and sending the uncondensed steam to the separator,

(d) sending the condensate sent to the tank to a separator by a pump,

(e) a method of recovering the condensable vapor component using the separator consisting of repeating sending the permeate separated vapor and condensate back to step (c).

In addition, the present invention,

(a) closing the first and second valves connected to the condenser and the third valve connected to the separator and supplying the mixed steam to the compressor,

(b) compressing the mixed vapor in a compressor,

(c) condensing the compressed steam in a condenser,

(d) quickly opening the first valve and sending some uncondensed steam to the separator with adiabatic expansion;

(e) if there is no condensate in the trap located between the condenser and the separator, opening the second valve to direct the condensate to the separator,

(f) opening the third valve to discharge residual vapor to the outside and to send the condensate to the storage tank,

(g) When the pressure inside the condenser and the pressure inside the separator are the same, it is a method of recovering the condensable vapor component using the separator comprising locking the first, second and third valves.

Hereinafter, the present invention will be described in detail.

The present invention uses the apparatus shown in FIG. 1 to compress the mixed vapor in the compressor 1 to separate the condensable vapors in the mixed vapor, and then in the condenser 2 connected to the compressor. Condensate into condensate and stored in tank (3). At this time, some condensed steam is sent to the separator (4). The steam separated by the separation membrane 4 may be returned to the flow of mixed steam through the condenser 2 and the process may be repeated to recover the condensable vapor in the mixed steam. Since the vapor permeated from the separation membrane 4 is significantly lowered by adiabatic expansion, it serves to help condensation when it passes through the condenser 2.

In addition, the present invention also compresses the mixed vapor in the compressor (1), and then in the condenser (2) connected to the compressor in order to separate the condensable vapor in the mixed steam using the apparatus shown in FIG. The vapor is condensed into condensate and stored in tank 3. At this time, some condensed steam is sent to the separator (4). The condensate sent to the tank is sent to the separator by a pump, and the vapor condensable in the mixed vapor is repeated by repeating the process of returning the permeate separated from the separator and the condensate back to the tank 4 through the condenser 2. Can be recovered. The condensate conveyed from the tank 3 to the separator 4 by the pump 5 has an effect of absorbing and condensing the vapors having passed through the separator 4 and inducing propulsion by sweeping. When the condensate having passed through the separator 4 passes through the condenser 2, the condensate is once again condensed to return to the tank 3 as a stable condensate.

In FIG. 2, the pump 5 is used to transfer the separated condensate to the separator 4, but it may be possible by the following method without the pump 5 as shown in FIG. 3.

i) Lock the first and second valves connected to the condenser and the third valve connected to the separator and condense the mixed vapor in the condenser 2 while raising the pressure to the desired pressure while viewing the pressure gauge 6 using the compressor 1. .

Ii) When the first valve is opened momentarily, adiabatic expansion occurs with the pressure induced by the compressor 1, and the pressure applied by the pressure gauge 6 'is read. This pressure causes a permeation separation of steam in the separation membrane 4 and the temperature between the first valve and the third valve is lowered by adiabatic expansion.

Organic vapors are more permeable at lower temperatures by the following permeability formula:

Membrane Permeability =

here Where i is the permeability of infinite dilution of component i, E _{p, i} is the active energy of component i, the normal gas is +, and the vapor condensed has-value.

b is a constant and _{PH, i} represents the pressure in (6 ') of i component.

Iii) If there is no condensate in the trap 7 located between the condenser and the separator, the second valve is opened to supply the condensate of the condenser 2 to the permeate of the separator 4. In this case, the vapor permeated by the separator 4 is absorbed and condensed by the condensate transferred from the condenser 2 and is stored in the tank 3. The condensate conveyed from the condenser 2 has a sweeping effect, thus maintaining the P _ratio ((6 ') pressure value / (6 ") pressure value in accordance with the operating conditions (maintaining propulsion force).

iv) Properly open the third valve to remove residual gas components.

All of the above procedures can be operated by automatic control and the operation tips to be careful during operation are as follows.

(1) When the pressure values of the pressure gauges 6 'and 6 "are the same, lock the first valve and the second valve again and return to the above order.

② When the condensate begins to accumulate in the trap (7), drain it and close the first valve and open it momentarily.

③ If the residual gas concentration discharged from the separation membrane 4 is higher than expected, close the third valve which is properly opened.

The use of the condensable vapor recovery method according to the present invention has the advantage of reducing the amount of coolant used and power costs.

Claims (1)

(a) closing the first and second valves connected to the condenser and the third valve connected to the separator and supplying the mixed steam to the compressor, (b) compressing the mixed vapor in a compressor, (c) condensing the compressed steam in a condenser, (d) quickly opening the first valve and sending some uncondensed steam to the separator with adiabatic expansion; (e) if there is no condensate in the trap located between the condenser and the separator, opening the second valve to direct the condensate to the separator, (f) opening the third valve to discharge residual vapor to the outside and to send the condensate to the storage tank, (g) A method for recovering condensable vapor components using a separation membrane comprising locking the first, second and third valves when the pressure inside the condenser is equal to the pressure inside the separation membrane.