JPS6193389A - Downflow thin film vaporizer - Google Patents

Abstract

PURPOSE:To reduce the cost while improving the performance by providing a flow rate regulating plate above heat transmission pipes which has holes in it to allow for a proper amount of flow to hit the inner wall of the heat transmission pipes so that the flow rate may be equalized among the heat transmission pipes and a uniform water film may be formed. CONSTITUTION:Hot water 7 flows from the bottom through a secondary pipe 5 and a pump 6, and after reducing its dynamic pressure by a buffle plate 10 in the upper part of a vaporizer shell 1, enters into a flow rate regulating plate 11. Orifices 11a in the same number as that of the heat transmission pipes 3 are provided in the underside of the flow rate regulating plate 11 at such an angle as to cause a collision against the wall of the heat transmission pipes 3, and a side plate extending up to the top of the vaporizer shell 1 on its side. A water level equivalent to the flow resistance of the hot water 7 out of the orifices is maintained. The hot water out of the orifices 11a hits the wall surface of the pipes 3, and flows down in a thin film. As the flow rate regulating plate 11 is separated from the pipe plate 2 and the heat transmission pipes 3, the inflow to the respective heat transmission is equalized regardless of the warpage error of the pipe plate 2 and the finishing tolerance of the top of the heat transmission pipes 3.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to improvements in falling film evaporators.

[Conventional technology]

Steam regeneration equipment, which is an energy-saving waste heat utilization device, generally uses a shell-and-tube system with soft water circulation.
Since the inside of the heat transfer tube is filled with water, the circulation flow rate becomes large in relation to the heat exchange %i, and the pump and piping 9- become large and expensive.

As one of the seven solutions, a method was developed in which a thin film of water was formed inside the heat transfer tube and flowed down by degrees Celsius, as shown in Figure 2, in order to reduce costs.

In FIG. 2, (a) is a schematic diagram of the entire apparatus, (b) is a perspective view of the upper part of the heat exchanger tube, and (C) is a longitudinal cross-sectional view of the same.

Further, each symbol in the figure is as follows.

21: Evaporator shell, 22: Tube plate, 23: Heat exchanger tube, 24
;Japanese plate, 25; Secondary piping, 26: Pump, 27: Hot water, 2B = Steam piping, 29: Turbine, 30: Perforated plate In order to form a uniform water film inside the heat transfer tube, each Two points must be satisfied: uniform flow distribution to the pipes and distribution: the mold forms a uniform water film within the pipes.

However, the problem is that the tube plate surface on which the heat exchanger tubes are attached may have a distortion error of about 6 ounces due to the workmanship, and the level error of the tube plate may occur due to the vertical accuracy of the main body during installation. In the method shown in FIG. 2 in which a V-shaped tube is provided at the upper end of the heat exchanger tube, the flow rate distribution to each heat exchanger tube varies due to the difference in the level of the upper end surface of the tube, and a uniform water film may not be formed.

[Problem that the invention seeks to solve]

The purpose of the present invention is to distribute the flow rate evenly to each heat transfer tube in order to reduce the cost and improve the performance of the falling film evaporator.
The goal is to establish a method to create a water film.

[Means for solving problems]

The present invention has proposed a falling thin film evaporator in which the inside of the hot water Yf heat transfer tube is caused to fall as a thin water film υIL. The present invention relates to a falling thin film evaporator characterized in that the same number of pores as the number of heat transfer tubes are provided on the lower surface of the flow rate adjusting plate toward the inner wall of each heat transfer tube.

In other words, does the device of the present invention provide an appropriate flow rate to the upper part of the heat transfer tube? The heat exchanger is characterized by providing a flow rate regulator with holes that collide with the inner walls of the heat exchanger tubes, thereby equalizing the flow rate to each heat exchanger tube and forming a uniform water film.

[Effect]

The present invention will be explained below based on FIG.

In FIG. 1, (a) is a schematic diagram of the entire apparatus, (b) is a perspective view of the upper part of the heat exchanger tube, and (C) is a longitudinal cross-sectional view of the same. Also,
Each code in the figure is as follows.

1: Evaporator shell, 2 = tube sheet, 3: heat transfer tube, 4: jam plate, 5: secondary piping, 6: pump, 7: hot water, 8: steam piping, 9: turbine, 10: collision Plate, 11: flow rate adjustment plate,
11a: The pore evaporator shell 1 constitutes the outer periphery of the device, and the hot water 7 is
From the lowest part, the fluid passes through the secondary pipe 5 and the pump 6, is reduced in dynamic pressure by the collision plate 10 above the evaporator 7, and flows into the flow rate adjustment plate 11.

The lower surface of the flow control plate 11 has the same number of pores 11a as the heat exchanger tubes 3 at an angle that collides with the wall surface of the heat exchanger tubes 6, and a side plate is provided on the side surface up to the top of the evaporator shell 1. The temperature within this flow rate regulating plate 11 is maintained at a water level corresponding to the flow resistance of the hot water 7 from the lower pore 11a. The hot water flowing from the pores 11a collides with the wall surface of the heat exchanger tube 3 supported by the tube plate 2 and the jam plate 4, forms a thin film, and flows down.

A portion of the water 7 evaporates and reaches the turbine 9 via the steam pipe 8.

〔Effect of the invention〕

(1) Flow rate adjustment plate 11 provided on the top of the evaporator shell 1
Since the tube sheet 2 and the heat exchanger tubes 3 are separated, the amount of inflow to each heat exchanger tube 3 is made uniform regardless of the distortion error of the tube sheet 2 and the finish of the top end of the heat exchanger tubes 3. be done.

(2) There is no need to improve the finishing accuracy of the upper ends of the tube sheet 2 and heat exchanger tubes 3, and the vertical accuracy of the installation is also improved.
) is the same as tη, resulting in cost reduction.

(3) The amount of hot water flowing into the heat exchanger tubes 6 is determined by the size of the pores 11a and the sufficient water level, so it is uniform regardless of the distortion of the tube sheet 2 or the finish of the upper end of the heat exchanger tubes 6. The vertical accuracy of the installation can be maintained using normal installation methods.

4, L, J side 1.・11 Description of the single process Figure 1 shows the flow F thin film evaporator of the present invention. ・Pi2 diagram shows the outline of the conventional one. In each figure, (a)
is a schematic diagram of the entire device, (b) is a perspective view of the upper part of the heat exchanger tube, (c
) is a longitudinal sectional view of the same.

Sub-agent: 1) Akira Sub-agent Ryo Hagi Hara - (C) Figure 2

Claims (1)

[Claims] In a falling thin film evaporator that allows hot water to flow down as a thin water film inside a heat transfer tube, a flow rate adjustment plate separate from the tube plate and the heat transfer tube is provided on the upper part of the shell constituting the outer periphery of the evaporator, and a flow rate adjustment plate is provided on the bottom surface of the flow rate adjustment plate. is a falling thin film evaporator characterized in that the same number of pores as the number of heat transfer tubes are provided on the inner wall of each heat transfer tube.