GB2168903A

GB2168903A - Distillation equipment

Info

Publication number: GB2168903A
Application number: GB08600374A
Authority: GB
Inventors: Toshisuke Shirota; Mitsuhara Wakasugi; Mitsuo Hattori; Hideo Goto
Original assignee: Yamato Scientific Co Ltd
Current assignee: Yamato Scientific Co Ltd
Priority date: 1982-10-15
Filing date: 1986-01-08
Publication date: 1986-07-02
Also published as: GB2128491B; GB2128491A; GB8600374D0; GB8327609D0; DE3336956C2; DE3336956A1

Abstract

A distillation device is provided with a heater comprising a heater body (27), a heater element embedded in the heater body, and a temperature sensor (34) embedded in the upper portion of the heater body. <IMAGE>

Description

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GB 2 168 903 A

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SPECIFICATION Distillation equipment

5 This invention relates to distillation equipment in which a water splash entrainment preventing means is arranged between a steam generating means and a condenser.

In general, in conventional distillation devices, 10 for the purpose of producing distilled water of high purity, there is provided between a steam generating means such as a boiler and a condenser a water splash entrainment preventing means such as a so-called baffle plate for preventing the en-15 trainment of water splash or unvaporized water in the steam generated by the steam generating means. The conventional water splash entrainment preventing means serves to cause the flow path of steam leading from the steam generating means to 20 the condenser to meander or is comprised of a baffle member such as a plate-shaped member or a rod-shaped member disposed in the flow path of steam so that water splash or unvaporized water can be removed from the steam. With such con-25 ventional distillation devices, however, it is impossible to prevent the entrainment of water splash or unvaporized water into the steam in a reliable manner and thus the conventional devices have not been satisfactory.

30 In view of the above, an object of the present invention is to provide a novel and improved distillation device which is capable of separating water splash or unvaporized water from the steam in a reliable and effective manner so that a highly pure 35 steam may be supplied to a condenser so as to obtain a distilled water of higher purity.

The above and other objects, features and advantages of the present invention will be apparent from the following detailed description of a pre-40 ferred embodiment of the invention when taken in conjunction with the accompanying drawings.

In the drawings,

Figure 7 is a side elevational view of a distillation device according to the present invention; 45 Figure 2 is a cross-sectional view of the essential parts of the present distillation device;

Figure 3 is a cross-sectional view taken along line Ill-Ill of Figure 2;

Figure 4 is a cross-sectional view of a throttle 50 valve for adjusting the flow rate of cooling water; and

Figure 5 is a cross-sectional view taken along line V-V of Figure 2.

Referring to the drawings and first to Figure 1, 55 therein is illustrated a distillation device, generally indicated at reference numeral 1, which is constructed in accordance with the principles of the present invention.

The distillation device 1 includes a base housing 60 3 and a main housing fixedly mounted thereon. On the base housing 3 there are removably mounted an untreated water tank 7 and a purified water tank 9.

The untreated water tank 7 is provided at its top 65 with a supply port 7a for supplying various kinds of fluids and at its bottom with a discharge port 7b having an external thread (not shown). The discharge port 7b is connected with a water supply pipe 13 arranged inside the base housing 3 by means of a connection nut 11 screwed over the external thread thereof so that the tank 7 can be mounted on or removed from the base housing 3 by tightening or loosening the connection nut 11.

Figure 2 illustrates the essential parts of the present distillation device. In this Figure, untreated water is supplied to a steam generating means or a boiler generally indicated at 17 by way of a supply port 15 connected with the water supply pipe 13. The boiler 17 has a casing 19 formed of super-hard glass which is provided near its bottom with a heater mounting opening 21 having an external thread and at its top with a steam outlet port 25 for connection with a condenser 23. The supply port 15 and the heater mounting opening 21 are projected outwardly and positioned in opposed relation with each other with a predetermined difference in their vertical height. At the heater mounting opening 21, there is mounted a heater body 27 which is formed by sintering ceramics into a pipe-shaped or a rod-shaped member with its tip end closed. The heater body 27 has a flange 29 integrally secured to its basal end and is inserted from the heater mounting opening 21 into the boiler casing 19 so that it is firmly attached to the boiler casing 19 at the heater mounting opening 21 by means of a fastening member 31 such as a nut, threadedly fitted over the external thread of the outer periphery of the heater mounting opening 21, with the flange 29 being in abutting engagement with an outer end of the opening 21.

As shown in Figure 3, a heating element 33 is embedded in the heater body 27 along its outer peripheral surface and a temperature sensor 34 is also embedded in the upper portion of the heater body 27. The heating element 33 and the temperature sensor 34 are formed by sintering tungsten simultaneously upon sintering of the heater body 27. As is clear from Figure 2, the heating element 33 extends along the length of the heater body 27 except for the basal portion thereof at which the heater body 27 is firmly held by the boiler casing 19. The heating element 33 is connected to a lead wire 35 firmly secured to the basal portion of the heater body 27 and the temperature sensor 34 is connected to a lead wire 37 secured to the basal portion of the heater body 27. The temperature sensor 34 serves to detect whether or not the upper portion of the heater body 27 is exposed above the surface of the water in the boiler casing 19, such a detection of the water temperature being effected by detecting a change in the resistance value of the temperature sensor 34 due to a rise in temperature.

With the above construction of the heater, when electric current is supplied to the heating element 33 to heat the water in the boiler casing 19, air bubbles are generated at the outer surface of the heater body 27. In this case, however, generating of air bubbles is substantially suppressed at the basal portion of the heater body 27 at which no

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heating element 33 exists. As a result, there are no air bubbles staying in a space 25 formed between the basal portion of the heater body 27 and the heater mounting opening 21 of the boiler casing 19 5 so that heating of the boiler 17 without any water contained therein is securely prevented.

Incidentally, when a water supply from the supply port 15 is stopped by some reason during distilling operation and the amount of water in the 10 boiler casing 19 is reduced to expose the upper portion of the heater body 27 above the water surface, the exposed portion of the heater body 27 is heated to a temperature much higher than that portion of the heater body 27 which is in the body 15 of the water. As a consequence of this, the temperature sensor 34 disposed at the upper portion of the heater body 27 is changed in its resistance value. Accordingly, when such a change in resistance value takes place, it is assumed that the up-20 per portion of the heater body 27 has been exposed above the surface of the water, as a result of which the supply of electric current to the heating element 33 is interrupted so as to prevent a portion of the heater body 27 from being locally 25 heated to an excessively high temperature. In addition, it is to be noted that heating of the heater body 27 with no water being supplied to the boiler 17 is positively avoided under the action of the temperature sensor 34.

30 Steam generated in the boiler 17 is led into the condenser 23 and cooled therein to turn into water. Between the boiler 17 and the condenser 23, there is provided a water splash entrainment preventing means 39.

35 The condenser 23 is in the form of a cylinder and is provided at its one end with a steam inlet port 23A and at its other end with a distilled water discharge port 23B from which the distilled water in the condenser 23 is discharged. Inside the cylindri-40 cal condenser 23 there is disposed a cooling pipe 41 in a helically wound form in which cooling water flows. The cooling pipe 41 is provided at its opposite ends with an iniet 41A and an outlet 41B for cooling water.

45 A throttle valve may be mounted at the inlet 41A or the outlet 41B for adjusting the flow rate of water in the cooling pipe 41. The throttle valve is constructed in such a manner as shown in Figure 4. The throttle valve includes a valve body 45 50 adapted to be coupled to the inlet 41A or the outlet 41B of the cooling pipe 41, the valve body being formed at its opposite ends with a pair of external threads 47A and 47B. The valve body 45 defines therein a valve chamber 51 of a large diameter and 55 a spring chamber 56 with a valve seat 49 formed therebetween. A stop ring 53 is fastened to the inner wail of the valve chamber 51 near the inlet end thereof. In the valve chamber 51 between the stop ring 53 and the valve seat 49 there is disposed a 60 valve member 55 for axial movement relative thereto which has a first throttle bore 55A of a relatively small diameter formed at its central portion. The valve member 55 is always urged to move in a direction toward the stop ring 53 under the action 65 of a resilient member 59 such as a coil spring arranged under compression in the spring chamber

56 between the valve member 55 and a shoulder

57 formed at one end of the spring chamber 56. Between the outer peripheral surface of the valve member 55 and the inner surface of the valve chamber 51 there is formed a relatively large clearance C which is in communication through a radial passage 63 in the valve member 55 with the inlet or upstream side of the valve chamber 51 defined therein by the stop ring 53 and the valve member 55, so that cooling water can flow from the upstream side of the valve chamber 51 toward the clearance C by way of the radial passage 63. When the valve member 55 is caused under the pressure of incoming cooling water to move against the biasing force of the resilient member 59, it is placed into abutting engagement with the valve seat 49 to block communication between the upstream and downstream portions of the valve chamber 51; by way of the radial passage 63 in the valve member 55 and the clearance C between the outer surface of the valve member 55 and the inner surface of the valve chamber 51. The valve body 45 defines therein a second throttle bore 65 of a diameter smaller than that of the first throttle bore 55A at its outlet side, the second throttle bore 65 being in communication with the spring chamber 56.

With the above construction of the throttle valve, cooling water flows into the inlet side 61 of the valve chamber 51 and out from the second throttle bore 65, as shown by arrows in Figure 4. In the normal condition, cooling water fed into the inlet side 61 of the valve chamber 51 passes through the first throttle bore 55A in the valve member 55 as well as through the radial passage 63 in the valve member 55 and the clearance C between the outer surface of the valve member 55 and the inner surface of the valve chamber 51 into the downstream side of the valve chamber 51 and thence into the second throttle bore 65 through the spring chamber 56. In this connection, it is to be noted that cooling water passing through the second throttle bore 65 is restricted to be held at a constant flow rate since the diameter of the second throttle bore 65 is much smaller than that of the inlet 61 of the valve chamber 51.

When the pressure of cooling water is raised to cause the valve member 55 to move against the biasing force of the resillient member 59, the valve member 55 is brought into abutting engagement with the valve seat 49 to block communication between the upstream and downstream portions of the valve chamber 51 by way of the radial passage 63 in the valve member 55 and the clearance C between the outer surface of the valve member 55 and the inner surface of the valve chamber 51, as a consequence of which cooling water flows from the inlet 61 of the valve chamber 51 into the spring chamber 56 leading to the second throttle bore 65 only through the first throttle bore 55A in the valve member 55. In this case, therefore, the flow rate of cooling water passing through the throttle valve is determined by the first throttle bore 55A, which is smaller in diameter than the second throttle bore

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65, so that the flow rate of cooling water is held at much the same level as in the case of the normal pressure of the cooling water although the pressure of the cooling water is higher than the normal 5 level.

Turning now to Figures 2 and 5, the water splash entrainment preventing means, generally indicated by reference numeral 39, is of the triple construction which includes an outer tubular member 39A 10 firmly coupled to the steam outlet port 25 of the boiler casing 19, an inner tubular member 39B integrally coupled to the steam inlet port 23A of the condenser 23, and an intermediate tubular member 39C interposed between the outer and inner tubu-15 lar members 39A and 39B for preventing a direct communication between the boiler 17 and the condenser 23. The intermediate tubular member 39C is integrally coupled to the outer and inner tubular members 39A and 39B and defines therein a con-20 densation chamber 39D. The intermediate tubular member 39C has a tubular side wall formed therethrough with a plurality of communication apertures 39E which are directed substantially toward the tangential lines of the inner tubular member 25 39B, as shown in Figure 5. The intermediate tubular member 39C also has a spherical bottom wall formed with a water discharge port 39F which is directed obliquely in a downward direction. The inner tubular member 39B has its lower portion pre-30 sented in the condensation chamber 39D and extends at its lower end downwardly to a position lower than any one of the communication apertures 39E.

With the above construction of the water splash 35 entrainment preventing means 39, when the water in the steam generating means such as, for example, the boiler 17 is heated by the heater body 27 to generate steam, the steam in the boiler 17 flows upwardly from the outlet port 25 into the outer tu-40 bular member 39A of the water splash entrainment preventing means 39 and from there jets into the condensation chamber 39D through the communication apertures 39E in the side wall of the intermediate tubular member 39C. In this case, since 45 the communication apertures 39E are directed substantially toward the tangential lines of the inner tubular member 39B, the stream of steam jetting into the condensation chamber 39D impinges against the side wall of the inner tubular member 50 39B so as to be turned therearound while descending toward the lower end of the inner tubular member 39B. Thereafter, the stream of steam flows through the inner tubular member 39B into the condenser 23 and is condensed therein to pro-55 duce distilled water which is to be discharged from the discharge port 23B.

Incidentally, when steam jetting from the communication apertures 39E in the intermediate tubular member 39C into the condensation chamber 60 39D impinges against the side wall of the inner tubular member 39B, as described in the foregoing, unvaporized water such as water splash contained in the steam is condensed to drop toward the bottom of the condensation chamber 39D. In this con-65 nection, it is to be noted that the steam descends turning around the inner tubular member 39B so that falling of the water droplets, condensed on the outer surface of the inner tubular member 39C, is facilitated to a great extent. Accordingly, unvapor-70 ized water is separated from steam in the condensation chamber 39D in a positive and effective manner whereby the condenser 23 is supplied with steam of good quality to provide distilled water of high purity. In addition, it will be understood that 75 water droplets accumulated in the spherical-

shaped bottom of the condensation chamber 39D flow down into the boiler 17 from the water discharge port 39F formed in the bottom of the intermediate tubular member 39C.

80 Incidentally, it will be recognized by those persons skilled in the art that the present invention is not limited to the embodiment as referred to above but may be put into practice in various forms by changing the matters of design. Thus, for example, 85 the water splash entrainment preventing means can be of other than the triple construction.

Claims

90 1. A heater for a distillation apparatus, comprising a heater body, a heater element embedded in the heater body, and a temperature sensor embedded in the upper portion of the heater body.
2. A heater according to Claim 1, wherein the 95 heater is formed by sintering ceramics into a pipe-

shaped or rod-shaped member.
3. A heater according to Claim 2, wherein the heater element extends along the length of the heater body except for the basal portion thereof.

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4. A throttle valve for a condenser of a distillation equipment, comprising a valve body defining therein a valve chamber and a spring chamber which has a smaller diameter than the valve chamber with a valve seat formed therebetween, a valve 105 member disposed in the valve chamber with a clearance between the member and the valve chamber, the valve member defining a first throttle bore and a radial passage therethrough and the valve chamber and spring chamber communicating 110 through the clearance with each other, the valve body also defining a second throttle valve opposing the first throttle valve, and a coil spring disposed in the spring chamber and always urging the valve member to move away from the valve 115 seat.
5. A distillation equipment, comprising a housing provided with a distillation device, an untreated water tank and a purified water tank, the untreated water and purified water tanks being removably

120 mounted in the housing.
6. A heater for a distillation apparatus, substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.
7. A throttle valve for a condenser of a distilla-125 tion equipment, substantially as hereinbefore described with reference to, and as shown in, Figure 4 of the accompanying drawings.

Printed in the UK for HMSO, D8818935, 5 86, 7102.

Published by The Patent Office, 25 Southampton Buildings, London,

WC2A 1AY, from which copies may be obtained.