JPS62102878A - Heat pump type solvent vapor washing apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is mainly used in the lacrimal manufacturing industry for automobiles, machine tools, etc., by heating and evaporating a solvent solution. This invention relates to an improvement of a heat pump type solvent vapor cleaning device for cleaning mechanical parts and the like.

(Prior Art) A conventional heat pump type solvent vapor cleaning device usually has a solvent vapor cleaning tank 2 equipped with a cooling pipe 1, a heat pump 5 equipped with an evaporator 3, a condenser 4, etc., as shown in FIG. , a coolant circulator 6 that connects the cooling pipe 1 and the evaporator 3, and a solvent circulator 7 that connects the solvent vapor cleaning tank 2 and the condenser 4. It is configured to recover the heat of condensation and heat the solvent liquid 9.

In addition, in FIG. 3, 2a is the liquid reservoir part of the steam cleaning tank 2, and 2b is the liquid reservoir part of the steam cleaning tank 2.
3a is the cleaning part of the steam cleaning tank 2, 3a is the cooling water pipe of the evaporator 3,
3b is a heat medium evaporation pipe of the evaporator 3, 4a is a solvent heating pipe of the condenser 4, 4b is a heat medium condensation pipe of the condenser 4, 6a is a coolant return pipe, 6b is a coolant feed pipe, and 7a is a solvent return pipe. 7b is a solvent liquid feeding pipe, 10 is an object to be cleaned, 11 is a coolant circulation pump, 12 is a solvent circumferential pump, 13 is a compressor, and 14 is an expansion valve.

Thus, the solvent liquid 9 in the solvent vapor cleaning tank 2 is heated by the solvent heating pipe 4a of the condenser 4 of the heat pump and evaporated. The generated solvent vapor is sent into the steam cleaning tank 2, cooled by the object to be cleaned 10 and the cooling pipe 1, and condensed.

At this time, the heat of condensation given to the cooling pipe 1 is recovered by the heat medium 16 of the heat pump 2 via the coolant 15 and the evaporator 3, and the temperature and pressure are increased by φ. Reused for heating.

In addition, the solvent liquid condensed on the outer surface of the object 10 to be cleaned performs a cleaning action while flowing down along the outer surface of the object, and the contaminated solvent liquid after cleaning is collected by a drain pan (not shown) or the like. After being cleaned by a purification device (not shown), it is returned to the liquid reservoir 2a of the solvent vapor cleaning tank 2.

The heat pump type solvent vapor cleaning tank shown in FIG. 3 can quickly and reliably clean the object 10 to be cleaned, and has excellent practical effects.

However, this solvent vapor cleaning device also has problems that need to be solved in terms of the thermal efficiency of the device.

That is, the solvent liquid 9 is heated in the solvent heating tube 4a of the condenser 4 as described above, and the solvent liquid 9 is heated in the heating tube 4a.
boils and evaporates. The generated gas-liquid mixture 17 is returned to the vapor phase (cleaning section) 2b of the cleaning tank 2 through the solvent return W7a, where it undergoes gas-liquid separation and becomes a cleaning solvent vapor 8.

Incidentally, the solvent in the solvent return pipe 7a is in a so-called gas-liquid two-phase flow, and the flow rate is high, so the flow resistance is considerably large. That is, the outlet (A) of the solvent heating tube 4a of the condenser 4
) in the cleaning section 2b of the cleaning tank 2.
The pressure will be higher than that at . However, here, λ is the frictional resistance, j is the local resistance coefficient, L is the length of the return pipe 7a (m),
G is the weight flow rate (Kg/m"H), f is the acceleration due to gravity (m/sec"), r = specific gravity of gas-liquid two-phase flow (Kg/m
'), D is the pipe diameter -.

On the other hand, since the solvent circulation pump 12 is installed in the liquid pipe section of the condenser 4, the solvent liquid in the condenser 4 is under a positive pressure corresponding to the pressure loss △P shown in equation (1) above. is applied, and the pressure becomes higher than the solvent liquid pressure in the cleaning tank liquid reservoir section 2b.

As a result, the boiling point of the solvent liquid increases, and unless the condensing temperature of the heat medium 16 of the heat pump 5 is increased by the increase in boiling point, the solvent liquid will not boil, and the heat transfer efficiency of the heat medium condensing pipe 4b of the condenser 4 will increase. In addition, for the heat pump 5, an increase in the condensation temperature of the heat medium 16 is not preferable because it leads to a decrease in the so-called coefficient of collapse (cop).

In addition, in order to lower the back pressure of the condenser heating tube 4a, (1)
In the formula, the tube diameter can be increased or the tube length can be decreased.

However, the former method results in lower economic efficiency and difficulty in construction, and the latter method results in inconvenience in arrangement, and is not a method that can be easily adopted in actual solvent vapor cleaning equipment.

As mentioned above, the conventional solvent vapor cleaning equipment has serious disadvantages due to the increase in back pressure of the solvent heating pipe 4a, and in particular, due to constraints on the plant layout, the solvent vapor cleaning equipment is installed at a location far away from the cleaning tank 2. In cases where the heat pump 5 must be installed, the disadvantage due to the increase in back pressure becomes extremely significant.

(Problems to be Solved by the Invention) The present invention was devised to solve problems such as a decrease in the coefficient of performance (COP) of a heat pump caused by an increase in back pressure in the solvent heating tube of the heat pump condenser. By reducing the back pressure on the outlet side of the solvent heating '14a, the increase in the boiling point of the solvent in the solvent heating pipe is suppressed,
To achieve a high immersion coefficient by preventing an increase in the condensing temperature of a heat pump condenser, and to maintain a good nucleate boiling heat transfer coefficient in the solvent heating tube to prevent the heating surface of the condenser from becoming too large. It is.

(Means for Solving the Problems) The present invention provides a solvent vapor cleaning tank equipped with a cooling pipe, a heat pump equipped with an evaporator and a condenser, and a refrigerant that connects the cooling pipe and the evaporator of the heat pump. In a heat pump type solvent vapor cleaning device comprising a circulator and a solvent circulator that connects the solvent vapor cleaning tank and a condenser of a heat pump, an ejector is interposed in a solvent return pipe of the solvent circulator; The basic structure of the invention is to operate the ejector by injecting a solvent liquid into the ejector using a pressurizing device to circulate the solvent and reduce the back pressure of the solvent heating pipe of the condenser.

(Function) By injecting the solvent liquid to the ejector installed in the solvent return pipe using a pressurizing device, a circulation force of the gas-liquid mixture is generated in the ejector, and the pressure on the outlet side of the solvent heating pipe is reduced. As a result, the boiling point temperature of the solvent in the solvent heating tube is prevented from increasing, and the condensing temperature in the condensing and condensing devices does not increase significantly, thereby preventing a decrease in the heat pump coefficient of performance.

Furthermore, by lowering the solvent pressure on the outlet side of the solvent heating tube, the boiling phenomenon of the solvent increases for the same amount of heat exchange, and a high heat transfer coefficient can be obtained.

(Example) Hereinafter, the present invention will be explained in detail based on FIGS. 1 and 2. Incidentally, in FIGS. 1 and 2, parts common to those in FIG. 3 are given the same reference numerals.

FIG. 1 is a schematic system diagram of a solvent vapor cleaning installation according to the first embodiment of the present invention, in which 2 is a solvent vapor cleaning tank;
6 is a heat pump, 6 is a coolant circulator, and 7 is a solvent circulation pipe.

The interior of the solvent vapor cleaning tank 2 includes a liquid reservoir 2a and a cleaning N2.
b, a cooling pipe 1 is disposed above the cleaning section 2b, and an object to be cleaned 10 such as a mechanical part is disposed in the center of the cleaning section 2b.

The heat pump 5 is composed of an evaporator 3, a condenser 4, a compressor 13, an expansion valve 14, etc. The evaporator 3 has a cooling water pipe 3a and a heat medium evaporation pipe 3b, and the condenser 4 has a solvent heating pipe. A pipe 4a and a heat medium condensing pipe 4b are provided, respectively.

The coolant circulator 6 includes a coolant return pipe 6a and a coolant feed pipe 6b.
The cooling pipe 1 and the evaporator cooling water w3a are
A coolant 15 such as water is circulated through it.

The solvent circulator 7 is composed of a solvent return pipe 7a and a solvent liquid feed pipe 7b, and the solvent liquid 9 is circulated through the solvent heating pipe 4a of the condenser 4.

Reference numeral 18 denotes an ejector interposed in the solvent return pipe 7a near the outlet side of the condenser 4, and a flow control valve 20 is connected to the ejector 18 by a pressurizing device 19 such as a solvent injection pump.
Through this, the solvent liquid 9 is injected from the liquid reservoir 2a of the solvent vapor cleaning tank 2 as an ejector operating fluid. In FIG. 1, 21 is a solvent injection pipe, and 22 is a pressure detector.

Next, the operation of the solvent vapor cleaning apparatus will be explained.

The cleaning of the object 10 to be cleaned with the solvent vapor 8, the condensation of the surplus solvent vapor 8 by the cooling pipe 1, the recovery of the heat of condensation of the solvent vapor by the heat pump evaporator 3, the heating of the solvent liquid 9 by the heat pump condenser 4, etc. are as described above. This is the same as in the case of the solvent vapor cleaning device, and the explanation will be omitted.

Then, when the pressurizing device 19 is activated and the solvent liquid 9 is sucked from the liquid reservoir 2a and injected into the ejector 18, the ejector 1
8, the gas-liquid mixture 17 on the outlet side of the solvent heating tube 4a is drawn and guided. As a result, the solvent circulator 7
A circulation driving force acts on the fluid within the system, and a guided flow of the solvent solution circulates within the system.

The control valve 20 of the pressurizing device/a19 is connected to the solvent heating pipe 4a.
It is controlled by a signal from a pressure detector 22 installed near the outlet side of the ejector, and the valve opening is controlled to maintain the pressure (P) at the outlet (A) at a predetermined level. The injection energy, that is, the injection amount and injection pressure of the fluid (solvent liquid 9) are adjusted.

It goes without saying that the distance between the ejector 18 and the condenser 4 is preferably as short as possible in order to lower the back pressure inside the solvent heating tube 4a.

Further, in this embodiment, the pressure at the outlet A of the solvent heating tube 4a is detected by the pressure sensor 22, and the injection energy of the working fluid applied from the pressurizing device 19 to the ejector 18 is adjusted accordingly. However, it is also possible to use a temperature sensor instead of the pressure sensor 22.

Furthermore, in this embodiment, the solvent circulator force of the solvent circulator 7 system is obtained only by the ejector 18, but if the circulation driving force is insufficient, a small volume of liquid is added to the solvent liquid feed pipe 7b. It is also possible to provide a circulation pump.

Further, when the solvent liquid 9 is contaminated with dissolved solids from the object to be cleaned 1O, the boiling point of the solvent [9] increases. Therefore, by detecting the purity of the solvent liquid and controlling the amount of solvent liquid sprayed to the ejector 18 to promote the solvent suction action, the back pressure of the solvent heating pipe 4a is reduced and the influence of the boiling point increase is compensated for. It is also possible.

FIG. 2 is a system diagram of a solvent vapor cleaning device according to a second embodiment of the present invention, in which the suction position of the solvent liquid injected to the ejector 18 by the pressurizing device 19 is different. If the distance between the heat pumps 5 is significantly large due to the arrangement, it will be difficult to ensure a sufficient amount of solvent circulation in the condenser 4 using only the ejector 18. A circulation pump 12 is provided in the feed pipe 7b, and the solvent liquid suction side of the pressurizing device 19 is branched and connected to the vicinity of the inertia 4 side of the solvent feed pipe 7b.

In this embodiment, the circulation pump 12 can adjust the required ring expansion amount of the first solution, and the ejector 18 can reduce the back pressure in the solvent heating pipe 4a.

(Effects of the Invention) In the present invention, an ejector that is applicable even when the fluid to be transported is a gas-liquid mixture is utilized, and the ejector is inserted near the 1/clamp outlet side of the solvent return pipe 7a. Because of this configuration, the pressure increase in the solvent heating tube 4a of the condenser is reduced. As a result, the boiling phenomenon caused by pressure rise is suppressed and re-liquefaction of the boiled solvent vapor is prevented, making it possible to maintain stable nucleate boiling 1 heat transfer with high heat transfer efficiency, and making it possible to downsize the condenser. .

In addition, since an increase in the boiling point of the solvent is prevented due to a pressure drop within the solvent heating tube 4a, an increase in the condensation temperature of the heat medium is also prevented on the heat pump side, and the Ff2i of the heat pump is prevented from increasing.
The coefficient improves.

Furthermore, by adjusting the flow rate of the solvent liquid injected from the pressurizing device to the ejector, the amount of solvent circulation can be easily controlled, and the boiling point due to changes in local flow resistance in the solvent circulation pipe or solvent contamination can be easily controlled. It becomes possible to correct the rise.

As mentioned above, the present invention has excellent practical utility.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing the main parts of the solvent vapor cleaning apparatus according to the first embodiment of the present invention, and FIG. 2 is a system diagram showing the main parts of the solvent vapor cleaning apparatus according to the second embodiment of the invention. It is a diagram. FIG. 3 is a schematic system diagram of a conventional solvent vapor cleaning apparatus. 1 Cooling pipe 2 Solvent vapor cleaning tank 2a Liquid storage part 2b Cleaning part 3 Evaporator 3a Cooling water pipe 3b Heat medium evaporation pipe 4 Condenser, various domains 4a Solvent heating pipe 4b Heat medium condenser 2 depressed pipe 5 Heat pump 6 Coolant circulator 6a Coolant return pipe 6b
Coolant feed pipe 7 Solvent r, l! Ring pipe line 7a Solvent return pipe 7b Solvent feed pipe 8 Solvent vapor 9 Solvent liquid 10 Object to be cleaned 11 Coolant circulation pump 12 Solvent circulation pump 13 Compressor 14 Expansion valve 15 Coolant 16 Heat medium
17 Gas-liquid mixture 18 Ejector 19
Pressure device 20 Control valve 21 Solvent injection pipe 22 Pressure detector Patent applicant Kanto Jidosha Kogyo Co., Ltd.

Claims (5)

[Claims] (1) a solvent vapor cleaning tank (2) equipped with a cooling pipe (1);
Heat pump with evaporator (3) and condenser (4)
5), a coolant circulator (6) connecting the cooling pipe (1) and the evaporator (3) of the heat pump (5), and a condenser (4) of the cleaning tank (2) and the heat pump (5). ), an ejector (18) is interposed in the solvent return pipe (7a) of the solvent circulation pipe (7). At the same time, the solvent liquid (9) is pumped to the ejector (18) by the pressurizing device (19) to operate the ejector (18), and the solvent is circulated and the solvent heating tube (4a) of the condenser (4) is heated. A heat pump type solvent vapor cleaning device characterized by reducing back pressure. (2) According to claim 1, the solvent liquid (9) is injected from the liquid reservoir (2a) of the solvent vapor cleaning tank (2) to the ejector (18) by a pressurizing device (19). heat pump type solvent vapor cleaning equipment. (3) The solvent liquid (9) is injected from the solvent liquid feed pipe (7b) of the solvent circulation pipe (7) to the ejector (18) by means of a pressurizing device. Heat pump type solvent steam cleaning equipment. (4) A pressurizing device (19) capable of controlling the flow rate and pressure of the solvent liquid (9) injected to the ejector (18) by the solvent pressure (P) on the outlet side of the solvent heating tube (4a). The heat pump type solvent vapor cleaning device according to item 1. (5) A pressurizing device (19) capable of controlling the flow rate and pressure of the solvent liquid (9) injected to the ejector (18) by the solvent temperature on the outlet side of the solvent heating tube (4a). A heat pump type solvent vapor cleaning device described in .