JPS6261692A - Method for treating hot washing water in soldering line - Google Patents

Abstract

PURPOSE:To aim at effective utilization of heat energy, by supplying hot water after washing to a reverse osmosis membrane to separate the same into a small quantity of a concentrate and a large quantity of pure water. CONSTITUTION:Hot water heated by a hot water heater 49 is supplied to an article to be soldered to wash the same. The hot water after washing is supplied to a pH control tank 21 where the pH thereof is adjusted and filtered by filtering machines 24, 25 to be supplied reverse osmosis membranes 27, 28 withstanding relatively high temp. under pressure by a pump 26 and separated into a relatively small quantity of a concentrate and a relatively large quantity of pure water by said reverse osmosis membranes 27, 28. The concentrate is sent to the waste water treatment facilities of a flocculative sedimentation system through a waste water pipeline 31 to treat waste water while pure water is sent to a hot water tank 45 through a recirculation pipeline 32 to be recirculated to the feed body 15 of a hot water washing tank 14 and reused. By this method, heat energy is conserved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for treating hot water for cleaning used in a soldering line.

[Conventional technology]

Conventionally, in a soldering line where objects to be soldered are soldered while being conveyed by a conveyor that moves along a fluxer, a preheater, a soldering bath, and a hot water cleaning bath, all of the hot water used in the hot water cleaning bath is We carry out wastewater treatment such as coagulation sedimentation and biological treatment.

[Problem that the invention seeks to solve]

Therefore, in the past, there were many hot water drains for general use.
Wastewater treatment IIA facilities are becoming larger, and the heat of hot water is being wasted outside, resulting in a large loss of thermal energy.

An object of the present invention is to reduce the amount of water discharged and make effective use of thermal energy by recovering and reusing most of the hot water used in the drought cleaning tank of the soldering line.

[Means for solving problems]

The present invention includes a fluxer 11, a pre-heater 12, and a solder bath 1.
3 and a soldering line in which objects to be soldered are soldered while being conveyed by a conveyor 15 that moves along a hot water cleaning tank 14. When starting this soldering line, cold water is heated by a hot water heater 49 to turn it into hot water. , supplying the warm water to the carrier 15 and the objects to be soldered which are heated by the preheater 12 and the soldering bath 13 and located on the hot water cleaning bath 14 for cleaning, and lowering the temperature of the hot water after cleaning as much as possible. The hot water is supplied to reverse osmosis membranes 27 and 28, which can withstand relatively high temperatures, and this reverse osmosis membrane separates the hot water into relatively concentrated water and relatively highly purified water, and the concentrated water is sent to wastewater treatment. However, in this hot water treatment method for cleaning in a soldering line, pure water is circulated at a relatively high temperature through the hot water heater 49 to the carrier 15 on the hot water cleaning tank 14, etc.

[Function] In the present invention, when starting the soldering line, the hot water heater 4
9 heats the cold water to make it hot water, and this hot water is supplied to the carrier 15 and the objects to be soldered which are heated by the pre-heater 12 and the solder bath 13 and are located on the hot water cleaning bath 14 to clean them.

This hot water for cleaning is supplied to a reverse osmosis membrane that can withstand relatively high temperatures without reducing the temperature as much as possible, and this reverse osmosis membrane converts the hot water into a relatively small amount of concentrated water and a relatively large amount of concentrated water. Separate into pure water.

Then, the concentrated water is treated as wastewater, and the pure water, which remains at a relatively high temperature, is circulated through the hot water heater 49 to the carrier 15 on the hot water cleaning tank 14, etc., and is reused. Therefore, it saves water and since the amount of wastewater is small, there is no need for large-scale wastewater treatment facilities.

The hot water heater 49 is used when starting the soldering line.
Used as a heater to raise the temperature of cold water, and then
It is used to control the temperature of hot water that is circulated at high temperature in contact with the heated carrier 15 etc. in the soldering line. Therefore, this hot water heater 49 consumes less energy.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings.

As shown in FIG. 1, objects to be soldered (for example, printed wiring boards) are conveyed by a carrier (carrier or holder) 15 that moves along a foam fluxer 11, a preheater 12, a solder bath 13, and a hot water cleaning bath 14. There is a soldering line where you solder while doing so.

Along the flow path of the used hot water from the hot water washing tank 14, there is a PH adjustment tank 21 for adjusting the hydrogen ion a1 degree (hereinafter referred to as PH), and a 1 ton storage tank for the pump. 22, filtration pump 2
3. First and second filters 24, 25, reverse osmosis pressure pump 26, and first and second reverse osmosis membranes 27 and 28 are provided in this order.

Further, the reverse osmosis 1127.28 is branched into a concentrated water drainage pipe 31 and a pure water circulation pipe 32. A solenoid valve 33 and a flow meter 34 are provided in the concentrated water drain line 31, and a solenoid valve 3G and a flow meter 37 are provided in parallel in a line 35 branched from the drain line 31, and , this pipe line 35 is returned to the PH adjustment tank 21 .

Further, a solenoid valve 41 and a flow meter 42 are provided in the pure water circulation line 32, and a solenoid valve 44 is further provided in a line 43 branched from this circulation line 32, and this line 43 is connected to the Return to H adjustment tank 21.

The tip of the circulation pipe 32 is left above the hot water tank 45,
Furthermore, it is opened onto the hot water cleaning tank 14 via a processing tank 46, a circulation pump 47, and a solenoid valve 48.

A hot water heater 49 is provided inside the hot water tank 45, and when starting the soldering line, this hot water heater 49 releases sufficient thermal energy to rapidly raise the temperature of the cold water to obtain hot water at a predetermined temperature. At the same time, during the soldering operation, the hot water heater 49 is operated auxiliary to control the temperature of the hot water.

In addition, with respect to the PH adjustment tank 21, a chemical tank 51° 52
A chemical solution for adjusting the hydrogen ion concentration is supplied from the pumps 53 and 54, and water is also supplied from the water supply 55 through the solenoid valve 56, and then into the PH adjustment tank 21. The inside of this adjustment tank is stirred by an installed agitator 57.

One in Figure 1 is a hydrogen ion temperature sensor,
LS is a switch that is activated by detecting a certain water surface level, PI is a pressure gauge, and PS is a pressure switch.
S is a pressure switch for protecting the reverse osmosis membranes 27, 28, CM is a conductivity sensor, and TH is a temperature sensor.

2, 3, and 4 show an integral unit configuration of the circuit described in FIG. 1, but the description thereof will be omitted by giving the same reference numerals.

Next, the operation of this embodiment will be explained.

First, when starting the circuit shown in Fig. 1, during the suspension of operation, sewage that is not concentrated water passes through the unpressurized reverse osmosis membranes 21 and 28 and enters the concentrated water drainage pipe 31. Since waste water is moving into the water circulation line 32, the solenoid valves 33, 41 are closed and the solenoid valves 36, 41 are closed.
44 is opened and the wastewater is returned to the PHI tank 21 via pipes 35 and 43. Then, the reverse osmosis membranes 27 and 28 are constantly operated by the pressurizing action of the reverse osmosis pump 26, and the IJI
When concentrated water and pure water can be separated into the water pipe 31 and the circulation pipe 32, the solenoid valve 36.44 is closed and the solenoid valve 33.41 is opened.
Pure water is sent to the hot water tank 45 using a shuttle.

And the beginning of the soldering line! (The hot water heater 49 is energized to the maximum extent, and the cold water is rapidly heated with the maximum thermal energy to become hot water. This hot water is heated by the pre-heater 12 and the solder bath 13, and becomes hot water. It is supplied to the carrier 15 located on the cleaning tank 14 and the objects to be soldered held by this carrier to clean them.

The PH of the hot water after washing is adjusted! After the PHA is adjusted in the tank 21, the filter is filtered by the filter 24, 25, and then the reverse osmosis membrane 2, which can withstand relatively high temperatures (for example, 60° C.), is filtered by the pump 26 without reducing the temperature as much as possible.
7.28 is pressurized and supplied at a pressure of 60 kg 10 i culm, and this reverse osmosis membrane 27.2111 separates the hot water into relatively raw concentrated water and a relatively large amount of pure water.

The ill condensed water is then sent through the drainage pipe 31 to a wastewater treatment facility such as a coagulation-sedimentation method, biological treatment method, or evaporation treatment method for wastewater treatment, and the purified water is passed through the circulation pipe 32 at a relatively high temperature. The purified water is then sent to a hot water tank 45, and by supplementary energization of the hot water heater 49 in this tank 45, the pure water is heated to a temperature of, for example, 70%.
While controlling the temperature to about ℃, the hot water washing lf! It is circulated to the carrier 15 on top of the carrier 14 and reused. The pure water that has come into contact with the carrier 15 etc. heated in the soldering line transfers heat from the carrier 15 etc. to the PHJ tank 21 in a high temperature state.
is circulated.

[Effect of excuse]

According to the present invention, hot water after cleaning is supplied to a reverse osmosis membrane that can withstand relatively high temperatures without reducing the temperature as much as possible, and the reverse osmosis membrane converts the hot water into a relatively small amount of concentrated water and a relatively small amount of concentrated water. The concentrated water is separated into a large amount of pure water, and the concentrated water is treated as wastewater, and the pure water is circulated in a relatively iE'X'fA state through the hot water heater to the carrier on the hot water washing tank, and then recycled. Since it is used, it saves water, and since the amount of wastewater is small, there is no need for large-scale wastewater treatment IM equipment. In addition, the hot water heater is used as a heater to raise the temperature of cold water at the time of starting the soldering line, and after that, the temperature of the hot water that is circulated at high temperature when it comes into contact with the heated carrier etc. in the soldering line. Since it is used for control, the heat energy consumed by this hot water heater is small during operation, making it an energy-saving hot water treatment method.

[Brief explanation of the drawing]

FIG. 1 is a fluid circuit diagram of an embodiment of the hot water treatment method for cleaning in a soldering line of the present invention, FIG. 2 is a front view of a wave block that unitizes the circuit, and FIG. 3 is a plan view thereof. FIG. 4 is a side view thereof. 11...Fluxer, 12...Buri heater, 13...Solder bath, 14...Hot water cleaning tank, 15...W1 feeder, 27° 28...Reverse osmosis membrane, 49...Drought water heater.

Claims (1)

[Claims] (1) In a soldering line where objects to be soldered are soldered while being conveyed by a conveyor that moves along a fluxer, preheater, soldering bath, and hot water cleaning bath, cold water is supplied by a hot water heater when starting the soldering line. Heating the water to make it hot, supplying the hot water to the carrier and the objects to be soldered that are heated by the preheater and the soldering tank and located on the hot water cleaning tank for cleaning, and lowering the temperature of the hot water after cleaning as much as possible. This reverse osmosis membrane separates the hot water into a relatively small amount of concentrated water and a relatively large amount of pure water, and the concentrated water is treated as waste water and purified water is A method of treating hot water for cleaning in a soldering line, characterized in that the hot water is circulated at a relatively high temperature through the hot water heater to a carrier on the hot water cleaning tank.