JPS5939301A - System for controlling supply amount of liquid to be concentrated in multistage concentrating apparatus - Google Patents

Abstract

PURPOSE:To make it possible to supply an optimum amount of sea water to each stages, by a method wherein the evaporation temp. of each stages or either one of each stage is measured to determine the optimum amount of the liquid to be concentrated. CONSTITUTION:The amount of heat supplied to a multistage concentrating apparatus is measured by arranging a temp. sensor 11 such as a thermocouple on the upper surface of the uppermost stage of a heating and condensing plate, and temp. information measured by the temp. sensor 11 is sent to a control box 12 while the opening degree of a valve in a second distributor 6 is controlled by the signal from the control box 12 and the supply amount of sea water to a final distributor 7 is regulated to control the water level of a tank 8. By this method, the amount of sea water supplied to all stages of the concentrating apparatus is adjusted to an optimum amount.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a concentrated liquid supply rate control system used in a specific multistage concentrator.

The specific multi-stage concentrator used in the present invention is capable of achieving the maximum concentration efficiency with the minimum amount of heat (h) without boiling a low-concentration solution or evaporating it under reduced pressure. It was developed at the request of the applicant (
(Patent application 1ft: No. 156-69649).

As shown in Figure 1, the multi-stage concentrator is constructed by arranging six or more heating condensing plates (El) to (IDn+1) with good thermal conductivity at intervals in an insulating case (1), and A plurality of concentration stages are formed by providing liquid absorption layers (Sl) to (S□) on the lower surface of the tank.

When the heat source (H8) is applied from above like solar heat, the liquid absorption JM (Sl) ~ (S becomes the concentrating part, and the upper surface of the plate (shame) ~ (gn+1) becomes the condensing surface. The liquid to be concentrated is from the supply pipes (Pl) to (Pn) to the liquid absorption layer (Sl) to (1
3n), and concentrated liquid discharge pipes (01) to (0□
) from the condensate discharge pipe (Wl) to (”
Condensate is discharged from n).

If the heat source is applied from below, such as geothermal heat or other waste heat, the concentration section and condensation section will be in opposite positions.

Hereinafter, the operation of the multistage concentrator used in the present invention will be explained using a heat source (H3).
) and seawater desalination using solar heat using solar heat as the liquid to be concentrated will be explained.

The multi-stage concentrator having the configuration described in No. 111 heats the plate (El) with solar heat, and sequentially transfers heat in the form of latent heat to the next stage by repeating evaporation → condensation of seawater at each stage. This board (El) ~ (Fn+l)
One surface becomes the evaporation surface and the other surface becomes the condensation section. However, a temperature gradient occurs from the upper stage to the lower stage due to heat loss such as heat being discharged to the outside of the thread due to the discharged distilled water and concentrated seawater, which causes a continuous cycle of evaporation and condensation. Therefore, if the evaporation temperature of the water absorption M (81) in the first stage is T1, the production of distilled water produced in the first stage m W4 L is approximately expressed by the linear equation based on the Frasius-Clapeyron equation.

1oA-%(1) for W (In the formula, A and B are constants.) As is clear from formula (1), as T1 increases, Wl increases, so in order to operate steadily and continuously, W
1fIJ of water corresponding to j must be replenished. As a result of the inventors' experiments and research, the seawater replenishment darkness F1
is approximately expressed by the following formula: %Formula% The constant ia is approximately 1.6 to 3.0, and ii
+j was found to be true.

If seawater is replenished to Shibukawa beyond this point, a large amount of heat will be consumed by the J11 heat of the seawater, and since there will be a large amount of evaporation residue, a large amount of heat will be discharged outside the threads, increasing thermal efficiency.

Moreover, even if it is too small, it will become too concentrated and problems such as scale and precipitation of solid salts will occur.

Furthermore, as mentioned above, the temperature of each stage is different, and there is a temperature gradient that gradually decreases from the side closer to the heat source.
Supply each edition? The most steel J+t of fu water also changes. That is, corresponding to the saturated vapor pressure curve, 11( is larger at high humidity in both evaporation and δ-condensation. Therefore, it is necessary to supply more fiσ water to the upper stage than to the lower stage.

By the way, when conditions such as stage spacing are the same, the attenuation rate Gt(=W) of the amount of distilled water produced between adjacent stages is less than 1 i-1, which is almost constant from a macroscopic perspective (j( Take i.

In other words, as described below, goods = 0.85 to 0.95.

Therefore, the seawater supply ff1F4+1 of the i+1st stage is expressed by the following equation.

Fi + l = aGl + 1 wi < Fl (II) As described above, the inventors of the present invention repeatedly conducted repeated tests of We discovered that the optimum amount of water to be supplied can be determined, and based on this principle, we developed a system that supplies the optimum amount of 71σ water to each stage.

That is, in the present invention, three or more heating condensing plates with good thermal conductivity are arranged at intervals in a heat insulating case, and a liquid absorption layer is provided on at least the lower surface of each plate to form a plurality of concentrating stages. In a multi-stage concentrator in which the liquid to be concentrated is heated and evaporated by passing it through the heat source on the back side of each heating condensing plate and condensing the vapor on the condensing surface of the heating condensing plate facing the other. A multi-stage concentrator characterized in that the amount of heat supplied or the temperature of at least one concentrating stage is measured, and the amount of liquid to be concentrated supplied to each stage is maintained at the optimum Mt based on information obtained from nuclear heat. The present invention relates to a concentrated liquid supply amount control system.

In this specification, "(the amount of heat supplied to a multi-stage concentrator) refers not only to the amount of heat supplied to the multi-stage concentrator itself, but also to the amount of heat supplied to a location near the multi-stage concentrator under almost the same conditions as the concentrator. It is a concept that also includes.

The temperature of the concentration stage may be measured for any one concentration stage or heating condensation plate, or for all stages or heating condensation plates.

First, a case will be described in which the amount of heat supplied to the multistage concentrator is measured and controlled.

The following description will be made using seawater as the liquid to be concentrated and solar heat as the heat source as a representative example.

FIG. 2 shows a system diagram of a scaled-up concentration system using the control system of the present invention, and FIG. 3 shows an embodiment of the multistage concentrator and final distributor used in the present invention.

The concentration system shown in Figure 2 consists of five stages of multi-stage condensation Pt (2
), the d9 water is sent from the tank (3) to the first distributor (5) by the main pump (4), divided into two equal parts and sent to the second distributor (6). This second distributor further divides it into six equal parts and sends it to the final distributor (7).

Five pipes are connected from the final distributor (7) to each stage of the concentrator (2).

The ratio of the amount supplied from the final distributor (7) to each stage is determined in advance through repeated experiments with reference to the formula (llI). An embodiment of the final distributor (7) in which the ratio of the supply amount is fixed will be described with reference to FIG.

The final distributor (7) consists of a tank (8) and five capillary tubes (9a) to (9θ), each capillary tube (9
The heads (10) of a) to (9e) communicate with the atmosphere.

The capillary tubes (9a) to (9e) have different diameters or tube lengths, so that one of the seawaters passing through the five capillary tubes can be adjusted to a predetermined ratio (Z).

Also, is there an increase or decrease in the amount of seawater passing through each gear pillar pipe in the tank (8)? You can control the water level by controlling the water level.

In other words, seawater σ to each stage of the concentrator (2)] Optimum control is by supplying rig water to the tank (8).
It can be controlled by ffi.

Therefore, the amount of seawater supplied to the final distributor (7), for example, the main pump (4), the first distributor (5) and (
or) It may be controlled by the second distributor (6).

Alternatively, a knob (not shown) may be provided to connect them for control.

In addition, as shown in FIG. 5, the water tank 11t may be controlled by a system that combines an elevated tank with zero gradient, a constant head tank (16), and a wax element valve (08) or a bimetallic valve.

In the embodiment shown in FIG. 6, the hot air supplied to the multistage concentrator is measured by arranging a humidity sensor Oυ such as a thermocouple on the top surface of the heating condensing plate in the uppermost stage.

The temperature information measured by the temperature sensor θυ is sent to the control box 02), and the opening degree of the pulp (not shown) in the second distributor (6) is controlled by the signal from the control box 02). Final distributor (7)
The amount of seawater supplied to #:N frJL/tank (8)
control the water level. As a result, the amount of water supplied to all stages of the concentrator is adjusted to an optimum amount.

When measuring the temperature at the top stage in this way, the processing in the control box 02) is as follows: It is only necessary to control the supply range from the second distributor so that the raw ore in the capillary tube (9a) for the first stage satisfies the above formulas (1) and (11). This is because the remaining capillary tubes (9b) ~ (
9θ), the supply ratios are set in advance so as to satisfy the above formula (lit).

Furthermore, even if a temperature sensor is placed in the middle stage of the concentrator, the supply area of all stages can be controlled in the same way.

Furthermore, the signal from the temperature sensor (1]) is sent to the main pump (
4) to control the output of the main pump, or use a diaphragm pump as the main pump (4) to control the stroke of the diaphragm. +'il shi may be used.

Temperature sensor as mentioned above? ,@! J-shrinking device? 1ft pull in the compressor section! j'↓Approximately the same as the upper surface of the compressor road - winter cropping area (, - distribution [t 'U-5 may be used to control the amount of seawater supplied; in this case, a differential temperature type pyranometer Measure the temperature of the heating part using the Hayabusa heating plate (or waste heat utilization).

For the I'A compression device not shown in FIG. 6, the above formula, (Il
As a result of repeated experiments by the present inventors, the attenuation factor G used in ) was in the range of approximately 0.85 to 0.95.

Also, for the distribution supply of YIV water from the final distributor (7), a capillary! In place of (9a) to (9e), valves (not shown) whose opening degrees are predetermined may be used.

Next, the case where the heat k (temperature) of each stage is constant (t) will be explained based on FIG. 4.

In this embodiment, the vibrators connecting the final distributor (7) and the concentrator (2) each have a first pulp (Vl) to (■
5) is provided, and the supply of sweetfish with 7゛ turtle water is adjusted for each stage.

The temperature information measured at each stage of the concentrator (3) is sent to the control box θ3), and the above equations (1) and (11
], and then sends controller No. 8 to the valves (■YU) to (V5) in each stage. In response to the split tube 1 signal, each valve (vl) to (v5) changes its opening degree by four degrees, and as a result, up to 14 shaku of seawater is supplied to each stage.

When a temperature sensor is provided at each stage in this way, it is possible to deal with changes in the wire film over time due to one continuous operation, and to avoid strain control.

You can do it with the normal 1 Soki circuit, but the number of stages is increased.
When the concentration system becomes complex, it can also be performed by a microprocessor.

Next, based on FIG. 5 and FIG. 6, an actual example will be explained in which the opening degree of the pulp is directly controlled by the amount of heat supplied near the t→p device to control the seawater supply hole.

In this embodiment, a main pump (4) and a first distributor (5) are used.
) is provided with a control section consisting of an elevated tank (a constant water distance tank (=) and a wax element valve 418).

The river water pumped out from the water measuring tank (3) by the main pump (4) is put into the elevated tank Q.

In addition, a level switch (154) is installed at the empty tank, and when the level switch (151) becomes low, the main pump (4,) is automatically operated intermittently to reduce the water level to 1% of the empty tank. W4N.

Supply from the static tank (+1) to the constant head tank (ball tap 07) is carried out by the gravity of seawater, and as a result, the water level in the constant head tank (06) is always constant. Seawater is supplied from the constant head tank θG) to the first distributor (5) by means of a wax element valve θ.

The wax element valve 08) is composed of one wax element □□□ and a valve sC2υ, as shown in FIG.

The wax element) is attached to the upper lid (c) of the valve part Qυ, and is covered with a glass cover (c). Is wax element (foundation) a valve part? υ shaft Q◆
A valve (21 is provided at the other end of the shaft ψ RIM Mj the seawater hoe.

Wax Element 021Gt This element expands and contracts the core ill of the wax element by utilizing the volume change of the wax enclosed therein depending on the amount of heat supplied to the element, for example, the amount of solar radiation.

When the amount of solar radiation increases, the wax in the wax element expands and 8 cl't expands, pushing down the shaft H and expanding B111 between the valve 9 o'clock and the valve seat 17) to increase the amount of seawater passing through. 1] When the radiation intensity decreases, the opposite action occurs and the shaft rises to 1u according to the amount of solar radiation due to the action of the spring (0).

In order to determine the flow rate according to the amount of solar radiation, based on the above equations (1) and (n) and experiments,
This can be done by adjusting the mounting position etc.

In this way, in this embodiment, ・■f to the first distributor (5)
The supply of q water, -4yx, that is, the supply of seawater to the final distributor (7), can be controlled by directly interlocking the temperature sensor (i.e. wax element) and the valve, unlike in the previous embodiment. Electrical and electronic processing mechanisms such as boxes are no longer required, reducing problems such as breakdowns and making maintenance extremely easy.

Note that similar control can be performed by using a bimetal instead of the wax element.

Multi-stage concentrator used in the present invention No. 1: It can be used not only for concentration and distillation of various solutions, but also for desalination of seawater. When using other solutions, it is necessary to determine the constant &, the attenuation rate Gi, and other conditions in advance for each solution based on the actual station.

[Brief explanation of the drawing]

□Figure 1 is a schematic sectional view of one embodiment of a multistage concentrator controlled by the control system of the present invention, Figure 2 is a system diagram of the control system of the present invention, and Figure 3 is another embodiment of the multistage concentrator. FIG. 4 is a schematic illustration of the embodiment of the control system of the present invention, and FIG. 5 is a perspective view of a state in which the control system and the final distributor are combined.
FIG. 6 is a partial vertical sectional view of the wax element valve.・(Main symbols in the drawing) (2) Two-stage concentrator (3): Seawater tank (4): Main latch (6): Second distributor (7): Final distributor (8): Tank (9a) )) (9b) - (9c), (9d), (9θ): Cavillary pipe (]l): Temperature sensor (b), 0■: Control box (IC1)S (Ez)・(E3)s ( '-Tl): Heating condensation plate (H8): Heat tjj (PL) N (P2), (P3), (Pn): Concentrated liquid supply pipe (Sl),
(S2), (S3% (''n): yi liquid layer (Vl), ('v2) -1(v3) 5ff4) N
(V5): Pulp (Wl), (W2)S (Wn) two condensate discharge pipes 1st
Figure S

Claims (1)

[Claims] 16 or more heating condensation plates with good thermal conductivity are arranged at intervals in an insulated case, and a liquid absorption layer is provided on at least the bottom surface of each plate to form a plurality of concentration stages, and the liquid to be concentrated is In a multi-stage concentrator that heats and evaporates vapor by passing the heat source of each heating condensing plate through a back-to-back or fist-force operation and condensing the vapor on the condensing surface of the facing heating condensing plate, the amount of heat supplied to the multi-stage concentrating device or Control of supply amount of liquid to be concentrated in a multi-stage concentrator, characterized in that the temperature of at least one concentration stage is measured and the amount of liquid to be concentrated supplied to each stage is maintained at an optimum level 17 (17) based on information regarding nuclear heat. system.