MULTI-STAGE DISTILLATION PLANT, METHOD FOR OPERATION OF SUCH A PLANT

Abstract

The invention relates to a multi-stage distillation system (1) comprising stages si, where i = 1, ..., N, wherein each stage si operates within a pressure and temperature range (pi, ti) greater than that of the following stages si + 1, wherein each stage si comprises an evaporator ei and a condenser ci, each evaporator ei and each condenser ci comprising a pressure-tight vessel (2) comprising a vapor chamber (6), wherein the vapor chamber (6) of each evaporator ei is in pressure relationship with the vapor chamber (6) of the condenser ei of the same stage si via a vapor pipe (7) having a large cross-section. Each outlet (5) of each evaporator ei is connected to a spray inlet (3) of the next evaporator ei + 1, and the outlet (5) of the last evaporator is connected to the spray inlet (3) of the first evaporator.E1 with a respective fluid line (8) to form an evaporator circuit, and each outlet (5) of each condenser ci is connected to the single inlet (3) of the preceding condenser ci-1 and to the outlet (5) of the first condenser c1 is connected to the spray inlet of the last condenser cn with a fluid line (9) to form a condenser circuit. According to the invention, at least one vapor line (10) is connected at one end to one of the fluid lines (9) between the condensers ci+1 and ci or to the fluid line (8) between the evaporators en and e1, and is connected at the other end to a vapor chamber which, during operation, has a pressure p greater than the pressure pi in the vapor chamber (6) of the condenser ci or the pressure p1 in the vapor chamber (6) of the evaporator e1. The invention also relates to a method for carrying out distillation in a system according to the invention, as well as a controller.

Description

According to the invention, at least one steam line (10) is connected at one end to one of the fluid lines (9) between the condensers Ci + let Ci or to the fluid line (8) between the evaporators En and El, and is connected at a second end to a steam chamber which, during operation, has a pressure P greater than the pressure Pi in the steam chamber (6) of the condenser Ci or the pressure Pi in the steam chamber (6) of the evaporator El. The invention also relates to a method for carrying out distillation in a system according to the invention, as well as a controller.

Claims

EP 16 704 179.7 PATENT CLAIMS 1. Multi-stage distillation installation (1) with levels Si at i=l,....n, each level Si operating in service in a pressure and temperature range (Pi,Ti) higher than its sequential level Si+1, each level Si comprising an evaporator Ei and a condenser Ci, each evaporator Ei and each condenser Ci comprising a pressure-resistant tank (2) with an upper spray inlet (3) for introducing and spraying added liquid (4a) into the tank (2), and with a lower outlet (5) for removing the liquid (4b) collected in the tank (2), and with a vapor compartment (6) between the spray inlet (3) and the collected liquid (4b),the vapor compartment (6) of each evaporator Ei being connected by pressure to the vapor compartment (6) of the condenser Ci of the same level Si by means of a pressure-resistant vapor conduit (7) with a large cross-section such that the pressure Pi can always be balanced in operation in the two vapor compartments (6) of a level Si and the outlet (5) of each evaporator Ei being connected to the spray inlet (3) of the next evaporator Ei + 1 and the outlet (5) of the last evaporator En to the spray inlet (3) of the first evaporator El with respectively a pressure-resistant liquid conduit (8) to an evaporator circuit and the outlet (5) of each condenser Ci being connected to the spray inlet (3) of the previous condenser Ci-1 and the outlet (5) of the first condenser Cl to the spray inlet (3) of the last condenser Cn with a pressure-resistant liquid conduit (9) to a condenser circuit,characterized in that at least one pressure-resistant steam pipe (10) is connected at a first end with, one of the pressure-resistant liquid lines (9) between condensers Citl and ci or with the pressure-resistant liquid line (8) between evaporators En and El and at a second end with a vapor compartment, which in service has a pressure P higher than the pressure Pi in the vapor compartment (6) of condenser ci and than the pressure Pn in the vapor compartment (6) of evaporator En to apply the liquid (4) with a higher pressure as well as to transport the liquid (4).

2. Distillation installation according to claim 1, characterized in that the vapor compartment with pressure P is a vapor compartment (6) of the distillation installation.

3. Distillation installation according to claim 1 or 2, characterized respectively by a pump (11) in the liquid line (8) of the evaporator circuit and in the liquid line (9) of the condenser circuit to obtain the predefined pressures of the liquids (4) at the beginning of the process.

4. Distillation installation according to any one of the preceding claims, characterized by a heater (12) in the liquid line (8) of the evaporator circuit before the evaporator El and a refrigeration unit (13) in the liquid line of the condenser circuit before the condenser Cn to achieve the predefined temperatures in the evaporator El and in the condenser Cn.

5. Distillation installation according to claim 4, characterized in that the heater (12) and the refrigeration unit (13) are equipped together partly as a heat exchanger (14).

6. Distillation installation according to! , any one of the preceding claims, characterized in that siphons (15) are disposed in the liquid lines (9, 8) between the condensers Cn to Cl and / or between the evaporators El to En to prevent the individual condensers Ci and / or the evaporators Ei to ! from running dry , System shutdown.

7. Distillation installation according to! , any one of the preceding claims, characterized in that each capacitor Ci comprises at ! , at the end of the distillation path there is a qaz line (17) connected to a vacuum pump (16) to remove the non-condensable qaz from the vapor compartments (6).

8. Distillation installation according to any one of the preceding claims, characterized in that each evaporator E1 is disposed on a deeper level than… , previous evaporator Ei in such a way that during!, In the execution of the process, the liquid (4) flows only through the pressure and level differences of each evaporator Ei into! , evaporator respectively according to Eitl without an electric pump being necessary for this.

9. Distillation installation according to any one of the previous claims, characterized in that each capacitor Ci+1 is arranged on a level positioned relative to its next capacitor Ci steam compartment such that during the execution of the process, the liquid flows from the Citl condenser by the differences in pressure and level and / or by the transport force of a steam line into the next condenser respectively without the need for an electric pump.

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14. Distillation installation according to any one of the preceding claims, characterized in that the condensers Cl and Cn are arranged at a level such that during the execution of the process, the liquid (4) flows by the pressure and level differences through the liquid line (9) from the circuit of condenser Cl to condenser Cn, without an electric pump being required for this. Distillation installation according to any one of the preceding claims, characterized in that the evaporators En and El are arranged at level such that during the execution of the process, the liquid (4) flows by the pressure and level differences and by the transport force of one or more vapor lines (10) through the liquid line (8) of the evaporator circuit from evaporator En to evaporator El, without an electric pump being required for this. Distillation installation according to any one of the preceding claims, characterized in that at least the tanks (2) of the first condenser Cl and of the last evaporator En respectively comprise a level sensor (23) for determining the levels of the liquid (4b) collected in the tanks (2). Distillation installation according to any one of the preceding claims, characterized in that in the evaporation circuit, a sensor (24) is preferably located near the last evaporator En to measure the concentration of the residues. A method for operating a distillation process using a distillation plant (1) according to any one of the previous claims, comprising an inlet (18) in the evaporator circuit, for conveying distillate liquid (4), and an outlet (19) from the evaporator circuit for removing liquid with a high concentration of residues, and a distillate outlet (20) from the condenser circuit for removing distillate (21) generated by the installation, characterized by the following process steps: a. Monitoring the liquid level in the evaporator circuit and in the condenser circuit, b. monitoring of residue concentration in the evaporator circuit, c. flow of the liquid with a high concentration of residues at the outlet (19), as soon as the liquid level in the evaporator circuit has reached a predefined maximum level and / or the concentration of residues in the evaporator circuit has reached a predefined maximum value, d. flow of distillate from the capacitor circuit to the distillate outlet (20) as soon as the liquid level in the capacitor circuit has reached a predefined maximum level, e. introduction of liquid (4) into the condenser circuit at the inlet (18) as soon as the liquid level in the evaporator circuit has reached a predefined minimum value and / or the concentration of residues in the evaporator circuit has reached a predefined maximum value. f. Repeat steps a to e until the process needs to be stopped.

15. A process according to claim 14, each condenser Ci at the end of the distillation path comprising a gas line (17) connected to a vacuum pump (16), characterized by the following process steps: ج. Determination of the temperature differences dTi in the vapor compartments (6) of the evaporator tanks (2) Ei and the capacitor Ci of the same level Si, b. removal of uncondensed gases in the vapor compartment (6) of the condenser Ci via the gas line (17) using the vacuum pump (16), as soon as the temperature difference dTi has reached a predefined maximum value, until dTi has reached a predefined minimum value, c. Repeat steps a and b until the process needs to be stopped.