SU1756653A1 - Steam-jet vacuum pump - Google Patents

Abstract

SUMMARY OF THE INVENTION: The cooled body (1) is partially filled with a working fluid (10). Steam pipes (3) with cone-shaped nozzles (4) are concentrically mounted in the housing (1). A heat pipe (5) is installed along the axis of the central steam line (3), the evaporation section is supported on the bottom (2) of the housing (1), and the condensation section is in the zone of the upper stage. Nozzles (4) are formed by cone-shaped tubes with the same conductivity of the heat flow, steam lines (3) are annular tubes with different conductivities, made corrugated with corrugations in the form of a multiple-flow helix and installed by the evaporative part on the bottom

Description

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The invention relates to vacuum technology, in particular to the design of steam jet vacuum pumps.

The purpose of the invention is to increase productivity.

The drawing shows a longitudinal section of a steam jet vacuum pump.

The steam jet vacuum pump contains a cooled case 1, a bottom 2 with labyrinth channels concentrically mounted on the latter in the case 1 steam lines 3 in the form of annular heat pipes with different heat flow conductivities, the latter being corrugated with corrugations in the form of a multiple spiral helix and installed the evaporation part on the bottom 2, and the condensation part in the nozzles 4 zone, while the latter are formed by conical heat pipes with the same conductivity of the heat flow, axial heat pipes 5, located along the axis of the central steam line, heater 6, partitions 7 with rectangular nozzle openings 8, separating the upper part of the pump from the vaporization area, a heat-resistant thermal insulation coating 9 placed on the outer surface of the steam lines 3 and nozzles 4 in the zone of the cooled part of the housing 1 pump working fluid 10 pump. The compositions of working fluids of heat pipes of steam lines 3 are selected based on the conditions for ensuring optimal fractionation of the working fluid 10 in the pump and the maximum thermal conductivity of the heat pipes taking into account the cracking temperature of the working fluid.

The working fluid 10 of the pump, heated on the bottom 2 to boil, evaporates and, rising, heats up on the walls of the vapor.

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wires 3 and axial heat pipe 5, accumulates under partitions 7 and then steam flows into the pump working area through rectangular nozzle holes 8 located on partitions 7. The steam jet, falling on the corrugations of the steam lines 3, moves along a multiple helix, overheats and drains on the walls of the steam lines 3 and the axial pipe 5. The dried and superheated steam flows out of the nozzles 4 of the steam lines 3, trapping gas that enters the pump from the pumped volume. The cooling of the steam jet in connection with the expansion in the nozzle is parried by the heat flux coming from the heater through the walls of the steam lines 3 and the nozzles 4, which have a higher thermal conductivity than the traditional ones. Due to the different thermal conductivities of the steam lines 3, the amount of heat supplied to the working fluid 10 in each individual steam line 3 is different, and therefore the intensity of boiling is different. Due to this effect and the labyrinth bottom 2, the oil in the pump heater 6 is fractionated. Condensate oil flowing along the walls of the housing 1 into the heater 6, first gets through the slots in the labyrinth channels into the space between the outer and inner tubes; passage through the maze, the oil is evaporated, depleted as it moves towards the inner tube with light fractions with high vapor pressure. The aged oil, consisting of fractions with low vapor pressure, enters the inner tube and is directed to the high vacuum nozzle 4.

Thus, the light fractions go to the lower steps, and the heavy fractions go to the upper ones.

In the proposed technical solution due to a significant increase in the conductivity of the heat flux by the steam lines 3 and nozzles 4, as well as the intensification

heat exchange between the walls of the steam lines 3, the axial heat pipe 5 and the working fluid improves pump performance, improves the ultimate vacuum, increases the maximum discharge pressure, improves the stability of the pump. In addition, the pump warm-up time is reduced, and the cooling time when stopped due to the increased thermal conductivity of the steam lines.

Claims (2)

1. A steam jet vacuum pump containing a cooled body, partially filled with working fluid, a heater, steam pipes with conical nozzles, concentrically installed in the body, and a heat pipe installed along the axis of the central steam line, the evaporation section of which rests on the bottom of the body pump steps, characterized in that, in order to increase productivity, the pump is equipped with conical and annular heat pipes and partitions with rectangular nozzles versts, the nozzles are formed by cone-shaped pipes with the same conductivity of the heat flow, the steam pipes are formed by annular pipes with different conductivities of the heat flow, the latter being corrugated with corrugations in the form of a multiple spiral helix and installed by the evaporation part on the bottom and condensing - in the nozzle zone, installed in steam lines above the working fluid. 2. A pump according to claim 1, characterized in that it is provided with a heat-resistant thermal insulation coating placed on the outer surface of the steam lines and nozzles in the area of the cooled part of the pump casing.