SU1611361A1 - By-pass device for single-or multistage evaporators of instantaneous boiling - Google Patents

Abstract

The invention relates to multi-stage flash boilers by-pass devices designed for desalinating seawater, desalting sewage and concentrating process solutions, and improves work efficiency by ensuring that the liquid is prepared for the evaporation process. The bypass device includes elements for forming a fluid flow (a constriction cavity of the stream and its subsequent expansion). Cavities that constrict the flow by means of a gas or steam supply are connected to the gas (vapor) space of this or previous evaporation chamber, and cavities that expand the flow are connected by means for supplying liquid to a space filled with liquid in the previous chamber or liquid inlet pipe. 3 il.

Description

The invention relates to single- and (or) multi-stage flash-boil-off evaporation plants (UMV) used to desalinate seawater, desalination of sewage and concentration of technological solutions.

The aim of the invention is to increase work efficiency by providing liquid preparation for the evaporation process.

FIG. 1 shows the proposed device with horizontal location; evaporation chambers; in fig. 2 and 3 are the same, with a vertical arrangement of the chambers, respectively, which follow under the previous one and the subsequent one above the next.

The main elements of the device are the elements to form

fluid flow, containing tapering cavities 1 and expanding cavities 2, as well as means 3 for supplying gas or steam to the converging cavity 1, means 4 for supplying fresh fluid to the expanding cavity. Means 3 and 4 are made either in the form of holes, for example, in partitions (Fig. 1), or in the form of supply pipes (Figs. 2 and 3). The means 5 serve to control the flow rate of the liquid (Fig. 2), and the means 6 and 7, dt, separate the vapor from the liquid (Fig. 2 and 3). In this case, the constricting cavity 1 is connected to the vapor space of this 8 or previous 9 evaporation chamber or to an external source (not shown) of steam (gas), and the expansion cavity is connected to the liquid space, the previous chamber or under the complete liquid pipeline (:House 10,

with

05

The device works as follows (it is about - time.

The fluid flow from the previous chamber 9 or from the inlet pipeline 10 enters cavity 1, where the flow velocity increases and the pressure drops, then the stream enters cavity 2, where its velocity decreases, and the pressure increases, from which the stream flows out and the next evaporation chamber. In MecTB I where cavities 1 and 2 communicate, the velocity of the fluid is greatest. Here, by means of means 3, gas (vapor) I is supplied from the vapor-gas space of this I 8 or the previous chamber 9 or from the outside. In the liquid stream, a large number of evaporation centers are formed into which intensive evaporation of the liquid occurs.

With the expansion of the fluid flow through 1); the heat and mass transfer sessors are slowed down due to the decrease in the temperature difference between the liquid and the vapor masses. The supply of fresh liquid to this zone contributes to its complete penetration.

The use of the proposed by-pass device, for example, in the production of urea, will allow

Effectively and at lower cost, ammonia and carbon dioxide dissolved in the solution flow in a vacuum evaporator and reduce the steam consumption with further concentration of the solution.

Claims (1)

Invention Formula A bypass device of single or multi-stage flash-boil-evaporating evaporators containing elements for forming a fluid flow placed at the inlet of the first and / or between adjacent evaporation chambers, characterized in that, to form a liquid, they contain successively narrowing and expanding cavities and supplying liquid pipe, while the narrowing cavity is connected to the vapor space this or the previous chambers or with an external source of steam, and the expansion cavity is connected to the liquid space of the previous chamber or to the inlet liquid pipe. . city / ig.2 Y