SU926501A1 - Preheater - Google Patents

Description

(54) HEATER

one

The invention relates to heat transfer devices and can be used primarily in the chemical and sugar industry for heating water and solutions.

Known heaters include shell-and-tube heat exchangers connected in series through the tube space and equipped with nozzles connected in parallel to the manifold for supplying steam to the tube side and fittings for removing non-condensable gases placed along the shell of each heat exchanger with a given HZ step.

This heater has the disadvantage of inefficient steam condensation in the annular space.

Secondary vapors, including non-condensable gases, such as air, ammonia, carbon dioxide and others, are commonly used to heat water and solutions. The presence in the pair of even unsustainable content of non-condensing gases drastically reduces the coefficient (}) of shock from the vapor to the pipe walls, and this is manifested more intensely than the vapor velocity in the annular space.

The steam entering the tube side (space 2 of the heater gets into a practically closed volume. At the same time, its speed drops from the maximum value at the entrance to the heater almost to zero

10 in parts of the annular space remote from the entrance of this heater. The non-condensable gases contained in the vapor of the enveloping heat exchange surface create a semi-permeable di ((x) y-

A barrier layer prevents the steam supply to the pipe walls, which significantly worsens the conditions of steam condensation and, consequently, reduces the efficiency of heat transfer from steam to the pipe steak.

20

Claims (2)

The purpose of the invention is the transfer of heat exchange by forced circulation of the heating medium in the annular space. The supplied chain is achieved by the fact that the heater contains tube-tube heat exchangers connected in series to the tube space and equipped with nozzles connected in parallel to the collector of the steam supply to the annular space and fittings to drain non-condensing gases placed along the casing of each pump exchanger with the specified pitch, additionally containing an ejector installed at the entrance to the collector and the annular space of each tetra exchanger is connected to the displacement chamber of the ejector center Additional shtutserov. At the same time, a separating plate is installed between each additional fitting and a number of open fittings for removal of non-condensing gases. FIG. 1 shows the proposed heater, a general view; in fig. 2, section A-A in FIG. 1. The heater contains standardized shell-and-tube heat exchangers 1 connected in series through the tubular space, equipped with nozzles 2-5 connected in parallel to the collector 6 under the steam into the annular space, nozzles 7-12 and removal of non-condensable gases placed along the casing of each heat exchanger with the specified pitch, an ejector 13, mounted at the entrance to the collector 6 and having a displacement chamber 14 connected to the annular space by means of additional fittings 15-20, separation plates 21-26, fittings 27 and 28 for draining condensate. Each of the heat exchangers contains pipes 29 fortified in tube sheets 30 and 31. The heater operates as follows. in a way. Bp of pipe 29 of each of the heat exchange NIKOV 1 is supplied by a heated medium (liquid or solution). The heating medium, steam is supplied to the annular space of each of the heat exchangers from the collector 6 through nozzles 2-5. In the heat exchange process between the liquid and steam, the latter condenses, the condensate drains to the tube sheets 31 and is removed through fittings 27 and 28. Segregated Non-condensable gases are removed through fittings 7-12. Some part of the steam (10-20%) from the annular space by the ejector 13 is sucked off and re-enters the annular space through the manifold 6. Thus, the heating medium is forced to circulate, the steam in the annular space of each of the shell-and-tube heat exchangers, increasing the heat transfer coefficient from heating medium steam to the walls of pipes. Dividing plates 21 to 26, installed between fittings 7 to 20, respectively, reduce steam losses when exhausting non-condensing gases through fittings: -7 to 12. Forced circulation of steam allows an increase in heat transfer from the steam to the pipe walls by 2-25%. . Claim 1. A preheater comprising shell-and-tube heat exchangers connected in series through the tube space and provided with nozzles connected in parallel to the collector of the steam supply to the annular space, and fittings for removal of non-condensing gases placed along the shell of each heat exchanger with a predetermined pitch, differing from that, in order to intensify heat exchange by implementing the forced circulation of the heating medium in the annular space, the heater is additionally soda INH ejector mounted at the inlet of the collector, and each annular space is connected to the camera teshyuobmennika bias ejector through additional nozzles. 2. A preheater according to claim 1, in accordance with the fact that a separator plate is installed between each additional nozzle and a number of located nozzle for removing non-condensable gases. Sources of information taken into account in the examination 1. P. Lebedev. Heat exchange drying and cooling plants. M .. Energie, 1972, p. 15. OmmfDKKff at 9 efc / 77efl yo FIG. I