SU1725939A1 - Evaporator - Google Patents

Abstract

The invention relates to a technique for the evaporation of solutions and can be used in the chemical and other sectors of the industry where the processes of separation and evaporation of solutions are necessary, and allows to intensify and stabilize the operation of the apparatus. The evaporator (A) contains a coaxial two-way heating chamber (K) with vertical pipes, a separator with a nozzle for evacuating the evaporated solution, nozzles for steam supply, condensate and non-condensable gases, a boiling point pipe and a solution supply pipe 00 - the lower chamber, The outlet is equipped with tubular nozzles directed upward along the A-axis and enclosed in a two-phase nozzle (C) located at the exit of the additional steam supply pipe, and C is placed in a confused-diffuser chamber fixed under K. 1 z.p. f-ly, 2 ill. cl

Description

The invention relates to the chemical, food, and metallurgical industries of the industry and can be used to evaporate solutions that do not form a significant precipitate on the heating surface.

The purpose of the invention is to intensify and stabilize the operation of the apparatus.

Figure 1 shows the evaporator, the overall appearance; FIG. 2 shows a pipe for feeding a starting product, provided at the outlet with tubular nozzles enclosed in a combined two-phase nozzle.

The evaporator consists of a two-way heating chamber 1 with vertical heating pipes 2, a separator 3 with a boiling pipe 4 and a lower chamber 5. The nozzles 6-8 are designed for steam supply, condensate drainage and non-condensing gases.

A pipe 9 is provided for removal of the solution to be evaporated from the separator 3. To supply the solution (initial product), a pipe 10 is inserted into the lower chamber 5, the outlet of which is plugged and the surface facing the heating chamber 1 is equipped with tubular nozzles 11 (figure 2).

The tubular nozzles 11 are positioned under the central beam of heating tubes 2, and the outlets are directed upwards (in this case along the axis of the apparatus).

The number and diameter of the tubular nozzles 11 are selected depending on the feed rate of the original product. The nozzles 11 are enclosed in a two-phase combination nozzle 12 placed at the outlet of the additional steam supply pipe 13 and arranged as shown in FIG.

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The outlet nozzle 12 is also located strictly under the central beam of the heating pipes 2 and directed upwards along the axis of the apparatus.

The feed unit for the source product and steam (pos. 11 and 12) is enclosed in a confusion-diffusive chamber 14 fixed to the tube plate of the heating chamber 1. The outlet opening of the nozzle 12 is located in the chamber 14 in the area of its narrowing (Fig. 1).

Evaporator works as follows.

The initial solution (for example, from an evaporator operating at a higher pressure) flows through pipe 10 and is divided into thin streams in nozzles 11, heating steam (a part of it from the total number) flows through pipe 13 into a combined nozzle 12, picks up and accelerates em streams of the initial solution, providing a quasi-homogeneous two-phase (vapor-liquid) flow at the outlet of the diffuser part of the nozzle 12. Due to the kinetic energy of this two-phase flow, a relative dilution is created in the confuser of chamber 14, resulting in the ejection of the circulating solution. In this case, the circulating solution is uniformly mixed with the initial one with simultaneous condensation of steam. In the diffuser section of the chamber 14, the mixture acquires an overpressure necessary for ascent into the central beam of the heating tubes 2, which creates an additional driving head and leads to an increase in the rate of natural circulation. In the heating pipes 2, the liquid, rising, heats up and boils when boiled into the pipe. Steam saturation in height and cross section of pipe 4 boils causing the main driving force of natural circulation. From the boiling pipe 4, the vapor-liquid mixture enters the separator 3, where it is separated into liquid and vapor phases. The secondary steam leaves the apparatus, and the solution is lowered along the

peripheral heating pipes 2 in the lower chamber, re-enters the confusion-diffuser chamber 14 and the cycle repeats. One stripped off solution is removed through the pipe 9. The heating steam (the main part of it) through the pipe 6 is fed into the annular space of the heating chamber 1, where it condenses. Condensate is removed through pipe 7, and non-condensable gases through pipe 8.

By supplying a portion of the heating steam through the pipe 10, the solution is preferably heated in the central ascending part of the apparatus, which creates an additional driving circulation force both during start-up and during operation, ensuring its stability.

Claims (2)

Invention Formula 1, Evaporating apparatus containing an axial two-way heating chamber with vertical pipes, a separator with a pipe for evacuating the evaporated solution, a boiling-up pipe located above the central beam of the pipes of the heating chamber, and pipes for supplying steam, condensate and non-condensing gases, different the fact that, in order to intensify and stabilize the operation of the apparatus, it is equipped with a confused-diffuser chamber, fixed under the central beam of the tubes of the heating chamber, with a steam supply pipe with a combined two-phase nozzle, nym at its outlet and placed in a converging-diffusing chamber and the pipe supplying the solution with tubular nozzles arranged in the combined two-phase nozzle, the outlet openings of the tubular nozzles directed upwards on the machine axis. 2. The apparatus according to claim 1, characterized in that the outlet of the combined two-phase nozzle is located at the narrowing level of the confuser-diffuser chamber. Fig.i