System and method for operating a liquid gas evaporator

Abstract

A system (1) and method for operating a liquid gas evaporator (3), comprising an evaporator (3), a trough (5) carrying the evaporator (3), a housing (7) which surrounds the evaporator (3) on three sides, at least one detector (9) for sensing liquid gas arranged in the trough (5), a line (11) for the distribution of vapor D on the fourth, non-housed side of the evaporator (3) arranged at the margin of the trough (5) which is not closed off by the housing (7), a feed (13), connected to the line (11), and a regulating valve (15) provided on the feed (13) and connected to the detector (9) and at least one shut-off valve (17).

Claims

1. A liquid gas evaporator system comprising: a liquid gas evaporator for evaporating a liquid gas into its gaseous aggregation state, a trough carrying the liquid gas evaporator, a housing disposed on the trough that has an open top side, three side walls that surround the liquid gas evaporator, and an open side disposed between the side walls, the open top side and the trough, wherein the open side of the housing forms a non-housed side of the liquid gas evaporator, at least one detector, arranged in the trough, for detection of the liquid gas and its gaseous aggregation state, a line for distribution of vapor D, which is provided on the non-housed side of the liquid gas evaporator, wherein the line has orifices for spraying the vapor D outside the line, configured such that upon exiting the line, the vapor D travels vertically upward relative to the line, a feed, connected to the line, for running the vapor D into the line, a regulating valve provided on the feed, wherein the regulating valve is connected to the at least one detector, and at least one shut-off valve that prevents a further feed of the liquid gas to the evaporator in the event of a leakage.

2. The system of claim 1, wherein the line extends over an entire width of the non-housed side of the liquid gas evaporator.

3. The system of claim 1, wherein the line has orifices at intervals that are oriented essentially vertically upward.

4. The system of claim 1, wherein the non-housed side of the liquid gas evaporator is oriented to face away from a plant for processing of the liquid gas or of its gaseous aggregation state.

5. The system of claim 1, wherein the system is arranged to be elevated in relation to a plant for processing of the liquid gas or of its gaseous aggregation state.

6. A method for operating the system of claim 1, the method comprising: a) evaporating a liquid gas into its gaseous aggregation state in the evaporator, b) detecting a concentration of the liquid gas or of its gaseous aggregation state in the trough carrying the evaporator, c) upon the detection of a predetermined critical concentration value of the liquid gas or of its gaseous aggregation state in the trough, actuating the regulating valve on the feed and consequently introducing vapor D into the line and closing the liquid gas feed to the evaporator by the at least one shut-off valve, d) spraying the vapor D out of orifices in the line, and e) forming a vapor curtain above the line on the non-housed side of the evaporator.

7. The method of claim 6, wherein the vapor curtain is formed at least over an entire width of the non-housed side of the evaporator.

8. The method of claim 6, wherein a liquid material forms during evaporation, a heavy gas that collects in the trough.

9. The method of claim 6, wherein the vapor D is fed with a pressure of at least 4 bar into the line.

10. The method of claim 6, wherein the vapor D is fed with a pressure of from 10 bar to 35 bar into the line.

11. The method of claim 6, wherein by the spraying of the vapor D in d), air is sucked in from outside the system and the liquid gas or its gaseous aggregation state is entrained out of the trough, thereby diluting the concentration of the liquid gas or the concentration of its gaseous aggregation state to a noncritical value.

Description

(1) Further aims, features, advantages and possibilities of use will be gathered from the following description of exemplary embodiments, not restricting the invention, with reference to the FIGURE. In this case, all the features described and/or pictorially illustrated constitute in themselves or in any combination the subject matter of the invention, even independently of their amalgamation in the claims or their back reference.

(2) FIG. 1 shows a diagrammatical illustration of the system 1 according to the invention.

(3) FIG. 1 shows diagrammatically the system 1 according to the invention in one embodiment. The evaporator 3, which is installed in a trough 5, is illustrated in the middle. The evaporator 3 is surrounded on three sides (here, left, front and rear) by the housing 7, the front side of the system 1 being illustrated, cut away, here, so that the third side of the housing 7 cannot be seen at the front. This housing 7 is absent on the fourth side (here, right). Instead, a line 11, which is supplied by a feed 13, is provided for vapor.

(4) Furthermore, in the trough 5, at least one detector 9 is arranged, which continuously measures the concentration of the liquid gas or of its gaseous aggregation state, evaporated in the evaporator 3, in the trough 5. When a critical concentration of the liquid gas is exceeded, the detector 9 directly or indirectly switches the regulating valve 15, so that the feed 13 is opened for the vapor D which flows with a pressure of at least 4 bar into the line 11. By means of a number of orifices 19, in particular bores, distributed over the length of the line 11, the vapor is sprayed, in order thereby to form a vapor curtain. At the same time, the further feed of liquid gas to the evaporator 3 is prevented by means of the shut-off valve 17.

(5) As is likewise evident from the illustration of FIG. 1, the housing 7 is open upwardly. For the present invention, there is no provision for providing a fixed cover or a fixed roof on the housing 7. However, an open structure, for example a grid, may function as covering. The fourth, non-housed side of the evaporator 3 may likewise be closed, for example, by means of a grid, in order to prevent unauthorized access. The implementation of the present invention is not impaired by the provision of such grids.

(6) If, in the event of a leakage of the evaporator 3, the liquid gas and/or its gaseous aggregation state intended to be evaporated therein escapes and collects in the trough 5, the detector 9 is provided. This device is suitable essentially for all heavy gases and liquid gases, for example for hydrocarbons with three to five carbon atoms. However, the device may also be used for higher hydrocarbons.

(7) Before an explosion-critical mixture of the liquid gas or its gaseous aggregation state and of air is reached, the vapor D is introduced into the line 11 and is sprayed via the orifices 19 in the line 11, so that, as already illustrated, the vapor curtain is formed. During the spraying of the vapor D, the liquid gas or its gaseous aggregation state is entrained out of the trough 5, while at the same time air is sucked in from outside the system 1. This entrainment causes such a high dilution of the liquid gas or its gaseous aggregation state that the mixture reaches a concentration which is noncritical for explosions. In particular, the injector action of the vapor D contributes to this.

(8) A concrete embodiment of the present invention is a propylene evaporator which precedes a plant for the production of acrylic acid.