U.S. patent application number 11/345430 was filed with the patent office on 2006-06-15 for apparatus for concentrating processed vegetable and fruit products by reverse osmosis.
This patent application is currently assigned to Kagome Kabushiki Kaisha. Invention is credited to Kiro Hayakawa, Kazuo Kagitani, Takahiro Kawana, Katsunobu Sumimura.
Application Number | 20060127550 11/345430 |
Document ID | / |
Family ID | 18875267 |
Filed Date | 2006-06-15 |
United States Patent
Application |
20060127550 |
Kind Code |
A1 |
Kawana; Takahiro ; et
al. |
June 15, 2006 |
Apparatus for concentrating processed vegetable and fruit products
by reverse osmosis
Abstract
An apparatus for concentrating a vegetable and/or fruit product
has a concentration unit having a plurality of tubular membrane
modules connected in series, a single-axis eccentric screw pump
connected to its inlet for supplying the product and another
single-axis eccentric screw pump connected to its outlet for
discharging the product concentrated by reverse osmosis by the
concentration unit. The product is supplied under a high-pressure
condition such that the pressure at the inlet is within a specified
range, and the apparatus is operated such that the pressure at the
outlet is also within another specified range and the pressure
difference between the inlet and the outlet be greater than a
certain minimum pressure value.
Inventors: |
Kawana; Takahiro; (Tochigi,
JP) ; Kagitani; Kazuo; (Tochigi, JP) ;
Sumimura; Katsunobu; (Tochigi, JP) ; Hayakawa;
Kiro; (Tochigi, JP) |
Correspondence
Address: |
BEYER WEAVER & THOMAS LLP
P.O. BOX 70250
OAKLAND
CA
94612-0250
US
|
Assignee: |
Kagome Kabushiki Kaisha
|
Family ID: |
18875267 |
Appl. No.: |
11/345430 |
Filed: |
January 31, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09919170 |
Jul 30, 2001 |
7026001 |
|
|
11345430 |
Jan 31, 2006 |
|
|
|
Current U.S.
Class: |
426/492 |
Current CPC
Class: |
B01D 61/022 20130101;
B01D 61/025 20130101; B01D 61/12 20130101; A23L 2/085 20130101;
B01D 63/063 20130101; B01D 2313/243 20130101; B01D 61/10 20130101;
B01D 2319/022 20130101 |
Class at
Publication: |
426/492 |
International
Class: |
A23P 1/00 20060101
A23P001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 16, 2001 |
JP |
2001-07529 |
Claims
1. An apparatus for concentrating a vegetable-fruit product, said
apparatus comprising: a concentration unit having an inlet, an
outlet and a plurality of tubular membrane modules connected in
series; a single-axis eccentric screw pump connected to said inlet
of said concentration unit for supplying the vegetable-fruit
product to said concentration unit; and another single-axis
eccentric screw pump connected to said outlet of said concentration
unit for discharging the vegetable-fruit product from said tubular
membrane modules, said apparatus serving to cause the
vegetable-fruit product to be concentrated by reverse osmosis by
causing the vegetable-fruit product to flow down under a pressured
condition to said concentration unit.
2. The apparatus of claim 1 structured for causing the
vegetable-fruit product to flow into said concentration in a
single-pass process.
3. The apparatus of claim 1 wherein the vegetable-fruit product
includes at least one selected from the group consisting of seeds,
epidermis and sarcocarp.
4. The apparatus of claim 2 wherein the vegetable-fruit product
includes at least one selected from the group consisting of seeds,
epidermis and sarcocarp.
5. The apparatus of claim 3 wherein said vegetable-fruit product is
a processed tomato product.
6. The apparatus of claim 4 wherein said vegetable-fruit product is
a processed tomato product.
Description
[0001] This is a divisional application Ser. No. 09/919,170 filed
Jul. 30, 2001, currently pending.
BACKGROUND OF THE INVENTION
[0002] This invention relates to an apparatus for concentrating
processed vegetable and/or fruit products by reverse osmosis.
[0003] Among the means for concentrating squeezed vegetable and/or
fruit juice, those by reverse osmosis without involving phase
changes are coming to be noted because concentrated products of a
higher quality can be obtained by this method than by more commonly
practiced methods by heating and evaporation. The present invention
relates to improvements in such means for concentration by reverse
osmosis.
[0004] There are many kinds of conventionally known methods of
concentrating vegetable and/or fruit juice by reverse osmosis,
including those by causing the squeezed juice to flow through a
concentration unit with a plurality of tubular membrane modules
connected together by a single-stage single-pass method (as
disclosed in Japanese Patent Publications Tokkai 52-136942 and
59-25675), by a multi-stage single-pass method (as disclosed in
Japanese Patent Publications Tokkai 5-15351 and 5-336937) and by a
multi-stage circulation method (as disclosed in Japanese Patent
Publications Tokkai 3-21326 and 3-58774). By the single-stage
single-pass method, use is made of only one stage of concentration
unit with a plurality of tubular membrane modules connected in
series and the squeezed juice is caused to flow through in a
single-pass process for reverse osmosis. By the multi-stage
single-pass method and the multi-stage circulation method,
concentration units each with a plurality of tubular membrane
modules connected in series are provided in two or more stages and
the squeezed juice is passed through either in a single-pass
process or in a circulating process for reverse osmosis.
[0005] With any of these prior art means for concentration by
reverse osmosis, a high-pressure pump is connected on the inlet
side of the concentration unit for supplying the squeezed juice to
the tubular modules and a pressure control valve is connected on
the exit side of the unit for discharging the concentrated product
from the tubular modules, and a plunger pump is usually used as the
high-pressure pump. Such prior art means usually have problems of
the following four kinds. (1) The use of a plunger pump causes a
pulsating motion, thereby disturbing the operating conditions at
the time of concentration by reverse osmosis and hence a stable
operation cannot be carried out. (2) Because the concentrated
product by reverse osmosis under a high-pressure condition (or
"pressured condition") is discharged suddenly through the
pressure-control valve into an atmospheric condition, the
discharged product tends to get scattered. Air is easily absorbed
in this process, requiring a troublesome process management for
preventing deterioration of product quality and bacterial
contamination. (3) In the field of food processing, there are
demands for concentrating processed vegetable and/or fruit products
which contain solid components such as seeds, surface skin parts
(epidermis) and meat parts (sarcocarp) by reverse osmosis but such
solid components get stuck easily at the inlet of the plunger pump
and the discharge valve as well as the parts of the
pressure-control valve with a small clearance. As a practical
matter, therefore, it is very difficult to concentrate by reverse
osmosis such a processed vegetable and/or fruit product containing
solid components. (4) If an attempt is forcibly made to concentrate
such a processed vegetable and/or fruit product by reverse osmosis,
its solid components are cut or crushed by the plunger pump or the
valve parts of the pressure-control valve and hence concentrated
products containing the solid components as they existed before the
concentration process cannot be obtained.
SUMMARY OF THE INVENTION
[0006] It is therefore an object of this invention to provide an
apparatus for concentrating by reverse osmosis a processed
vegetable and/or fruit product containing solid components such
that these originally contained solid components keep more or less
their original forms.
[0007] The present invention is based on the discovery made by the
present inventors as a result of their research in view of the
object described above that such object can be achieved by
connecting a single-axis eccentric screw supply pump on the inlet
side of the concentration unit for supplying a processed vegetable
and/fruit product and a single-axis eccentric screw discharge pump
on its outlet side for discharging a concentrated product by
reverse osmosis.
[0008] Thus, this invention relates to an apparatus for
concentrating a processed vegetable and/or fruit product by reverse
osmosis by causing it to flow under a high-pressure condition to a
concentration unit with a plurality of tubular membrane modules
connected together, characterized wherein a single-axis eccentric
screw pump is connected on the inlet side of the concentration unit
for supplying the processed vegetable and/or fruit product and
another single-axis eccentric screw pump is connected on the outlet
side of the concentration unit for discharging the product which
has been concentrated by reverse osmosis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The accompanying drawings, which are incorporated in and
form a part of this specification, illustrate embodiments of the
invention and, together with the description, serve to explain the
principles of the invention. In the drawings:
[0010] FIG. 1 is a schematic structural diagram of a concentration
apparatus by reverse osmosis embodying this invention; and
[0011] FIG. 2 is a schematic structural diagram of another
concentration apparatus by reverse osmosis embodying this
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0012] An apparatus according to this invention is for
concentrating a vegetable and/or fruit product by reverse osmosis
by causing it to flow under a high-pressure condition to a
concentration unit with a plurality of tubular membrane modules
connected together. For the convenience of disclosure, processed
products of this kind will be hereinafter referred to as a
"vegetable-fruit product". Representative examples of
vegetable-fruit product include squeezed juices of vegetables,
fruits and their mixtures. The tubular membrane modules are modules
having a tubularly shaped semipermeable membrane supported inside a
cylindrical body. Commercially available modules of this kind may
be used but it is preferable to use a tubular semipermeable
membrane with salt rejecting ratio of 90% or greater and it is even
more preferable to use such a membrane with salt rejecting ratio of
99% or greater. When a vegetable-fruit product is caused to flow
into a concentration unit with a plurality of tubular membrane
modules connected together, in a multi-stage single-pass process or
a multi-stage circulating process, it is preferable to use a
tubular semipermeable membrane with salt rejecting rate 99% or over
at least for the concentration unit at the last stage.
[0013] As explained above, the vegetable-fruit product may be
caused to flow to the concentration unit in a single-stage
single-pass process, the multi-stage single-pass process or the
multi-stage circulating process but the single-stage single-pass
process is preferable for obtaining a concentrated product of a
high quality by reverse osmosis in a more stable operation and
under an easier process management. By this method, only one stage
of concentration unit with a plurality of tubular membrane modules
connected together is provided and a vegetable-fruit product is
caused to flow into such a single-stage concentration unit in a
single-pass process.
[0014] An apparatus for concentration by reverse osmosis embodying
this invention is characterized as having a single-axis eccentric
screw pump connected on its inlet side for supplying a
vegetable-fruit product to the tubular membrane modules and another
single-axis eccentric screw pump connected on its outlet side for
discharging from the tubular membrane modules the vegetable-fruit
product which has been concentrated by reverse osmosis. This is in
contrast to a prior art apparatus for concentration by reverse
osmosis having a plunger pump connected on its inlet side and a
pressure control valve on its outlet side.
[0015] A single-axis eccentric screw pump is commonly referred to
as a Mohno-pump and has been disclosed, for example, in Japanese
Patent Publications Tokkai 7-77172, 8-21370 and 9-264264.
Mohno-pumps produced, say, by Heishin Engineering & Equipment
Co., Ltd. may be used for the purpose of the present invention,
comprising a driving mechanism, an inlet part, a pump part and an
outlet part, with the pump part provided with a stator and a rotor.
The stator is essentially a female screw mainly of an elastic
material having a female screw hole with an opening of an elongated
circular sectional shape formed continuously in the longitudinal
(axial) direction. The rotor is a sectionally circular male screw
of a metallic material. The rotor is inserted into the stator, and
articles are adapted to be transported thereby as the rotor is
rotated around its eccentric axis through the inlet part by the
driving mechanism.
[0016] The single-axis eccentric screw pump, as described above,
includes a connector in the inlet part for communicating the rotary
motion of the drive shaft of the driving mechanism to the rotor of
the pump part. Many different kinds of such a connector are known,
including a coupling rod having universal joints at both its ends,
screws, those with elongated stator and rotor for obtaining high
discharge pressure and those with two units connected in series.
For the purpose of this invention, it is preferable that the
single-axis eccentric screw supply pump should have a high
discharge pressure and more preferably a discharge pressure greater
than 3 MPa.
[0017] According to the present invention, a pressure gauge is
usually inserted between the single-axis eccentric screw pump for
supply on the inlet side of the concentration unit and the tubular
membrane modules and another pressure gauge between the single-axis
eccentric screw pump for discharge on the outlet side of the
concentration unit and the tubular membrane modules such that the
numbers of rotation of these pumps are frequency-controlled through
an inverter provided with a calculation-control function on the
basis of the pressure values measured by these pressure gauges. As
an example, the number of rotation of the supply pump may be kept
at a constant rate while the number of rotation of the discharge
pump may be frequency-controlled through the inverter on the basis
of the pressure value measured by the pressure gauge on the outlet
side. As another example, the number of rotation of the discharge
pump may be kept at a constant rate while the number of rotation of
the supply pump may be frequency-controlled through the inverter on
the basis of the pressure value measured by the pressure gauge on
the inlet side. As still another example, the numbers of rotations
of both pumps may be frequency-controlled through their
individually corresponding inverters on the basis of the difference
between the pressure values measured by the two pressure gauges. In
each of these examples, upper and lower limit values are set for
each of the pressure gauges such that the numbers of rotations of
the pumps can be frequency-controlled within the limits between
these upper and lower limit values.
[0018] As explained above, single-axis eccentric screw pumps are
characterized wherein articles are transported as the rotor of the
pump part rotates around its eccentric axis and hence the articles
are not likely to be damaged. Since vegetable-fruit products are
supplied to the tubular membrane modules according to this
invention, no pulsating motion results and hence the operation for
the concentration by reverse osmosis can be stabilized. Since the
present invention makes use of this favorable characteristic of
single-axis eccentric screw pumps to discharge concentrated
products gradually from the tubular membrane modules under a
high-pressure condition into an atmospheric condition, the
discharged products do not scatter around and hence do not absorb
air. Thus, the process management becomes easier according to this
invention.
[0019] An apparatus according to this invention can be used
effectively also for concentrating vegetable-fruit products
containing solid components such as seeds, peels and fruit meats by
reverse osmosis because the single-axis eccentric screw pumps on
the inlet and outlet sides are not clogged by such solid
components. Since these pumps do not cut or crush such solid
components, the solid components originally contained in the
vegetable-fruit product remain more or less in their original forms
during the process of concentration by reverse osmosis. Even in the
case of tomatoes with relatively weak structure, processed tomato
products containing seeds, skins and meat parts can be similarly
concentrated by reverse osmosis.
[0020] A method according to this invention is characterized as
using an apparatus as described above to concentrate a
vegetable-fruit product by reverse osmosis. When a vegetable-fruit
product is concentrated by reverse osmosis by a method of this
invention, there is no particular limitation as to the content of
solid components but those containing solid components in an amount
of 30-60 weight % are suited. Neither is the invention particularly
limited in terms of the pressures at the time of concentration by
reverse osmosis, it is preferred to operate with the inlet pressure
of the concentration unit within the range of 3-5 MPa, the outlet
pressure of the concentration unit within the range of 1-3 MPa and
under the condition that the pressure difference between the inlet
side and the outlet side be greater than 1.5 MPa.
[0021] FIG. 1 shows schematically an apparatus embodying this
invention, adapted to cause a vegetable-fruit product to flow into
a concentration unit by a single-stage single-pass process, having
a single stage of concentration unit 21 with a plurality of tubular
membrane modules 11 connected in series. Each module 11 supports a
tubular semipermeable membrane (not shown) with salt rejecting rate
of 99%.
[0022] Connected to the inlet side of the concentration unit 21 is
the discharge outlet of a supply pump 31 which is a single-axis
eccentric screw pump for supplying a vegetable-fruit product to the
tubular membrane module 11 on the inlet side. A pressure gauge 41
on the inlet side is provided between the supply pump 31 and the
tubular membrane module 11 on the inlet side. The inlet part of the
supply pump 31 is connected through a valve to a storage tank 51
into which a vegetable-fruit product is supplied for storage.
[0023] Connected to the outlet side of the concentration unit 21 is
the suction inlet of a discharge pump 61 which is another
single-axis eccentric screw pump for discharging from the tubular
membrane modules 11 a vegetable-fruit product which has been
concentrated by reverse osmosis inside the concentration unit 21. A
pressure gauge 71 on the outlet side is provided between the
tubular membrane module 11 on the outlet side and the discharge
pump 61. The pressure gauge 41 on the inlet side is connected to an
inverter 81 provided with a calculation-control function, and the
inverter 81 is connected to the driving mechanism of the discharge
pump 61 and serves to frequency-control the number of rotations of
the discharge pump 61 on the basis of the pressure value measured
by the pressure gauge 41 on the inlet side. The outlet part of the
discharge pump 61 is connected through a flow meter 91 to another
storage tank 52 for storing vegetable-fruit products which have
been concentrated by reverse osmosis.
[0024] While the supply pump 31 is rotated at a constant rate and
the number of rotations of the discharge pump 61 is
frequency-controlled, as explained above, a vegetable-fruit product
is supplied to the tubular membrane module 11 on the inlet side
from the storage tank 51 successively through the supply pump 31
and the pressure gauge 41 on the inlet side. After it is
concentrated by reverse osmosis inside the concentration unit 21
having a plurality of tubular membrane modules 11 connected in
series, the concentrated product is stored in the storage tank 52
successively through the tubular membrane module 11 on the outlet
side, the pressure gauge 71 on the outlet side, the discharge pump
61 and the flow meter 91. The liquid which permeated through the
tubular semipermeable membranes supported by the individual ones of
the tubular membrane modules during the concentration process by
reverse osmosis in the concentration unit 21 is collected in a
receptacle 101 provided at the bottom of the concentration unit
21.
[0025] FIG. 2 shows schematically another apparatus embodying this
invention characterized as causing a vegetable-fruit product to
flow down to a concentration unit for processing by a two-stage
circulation process, comprising a first (upstream) concentration
unit 22 and a second (downstream) concentration unit 23 which are
connected together in series, each having a plurality of tubular
membrane modules (respectively 12 and 13) connected in series, such
that a portion of the product concentrated by osmosis by the
downstream concentration unit 23 is circulated back. Each of the
modules 12 and 13 supports a tubular semipermeable membrane (not
shown) with salt rejecting rate of 99%.
[0026] Connected to the inlet side of the upstream concentration
unit 22 is the discharge outlet of a supply pump 32 which is a
single-axis eccentric screw pump for supplying a vegetable-fruit
product to the tubular membrane module 12 on the inlet side. A
pressure gauge 42 on the inlet side is provided between the supply
pump 32 and the tubular membrane module 12 on the inlet side. The
inlet part of the supply pump 32 is connected through a valve to a
storage tank 53 into which a vegetable-fruit product is supplied
for storage.
[0027] Connected to the outlet side of the concentration unit 22 is
the suction inlet of a discharge pump 62 which is another
single-axis eccentric screw pump for discharging from the tubular
membrane modules 12 a vegetable-fruit product which has been
incompletely concentrated by reverse osmosis inside the
concentration unit 22. A pressure gauge 72 on the outlet side is
provided between the tubular membrane module 12 on the outlet side
and the discharge pump 62. The pressure gauge 42 on the inlet side
is connected to an inverter 82 provided with a calculation-control
function, and the inverter 82 is connected to the driving mechanism
of the discharge pump 62 and serves to frequency-control the number
of rotations of the discharge pump 62 on the basis of the pressure
value measured by the pressure gauge 42 on the inlet side. The
outlet part of the discharge pump 62 is connected through a flow
meter 92 to another storage tank 54 for storing vegetable-fruit
products which have been incompletely concentrated by reverse
osmosis.
[0028] Connected to the inlet side of the downstream concentration
unit 23 is the discharge outlet of a supply pump 33 which is still
another single-axis eccentric screw pump for supplying the
aforementioned incompletely concentrated vegetable-fruit product to
the tubular membrane module 13 on the inlet side. A pressure gauge
43 on the inlet side is provided between the supply pump 33 and the
tubular membrane module 13 on the inlet side. The inlet part of the
supply pump 33 is connected through a valve to the storage tank
54.
[0029] Connected to the outlet side of the concentration unit 23 is
the suction inlet of a discharge pump 63 which is still another
single-axis eccentric screw pump for discharging from the tubular
membrane modules 13 a vegetable-fruit product which has been
further concentrated by reverse osmosis inside the concentration
unit 23. A pressure gauge 73 on the outlet side is provided between
the tubular membrane module 13 on the outlet side and the discharge
pump 63. The pressure gauge 43 on the inlet side is connected to an
inverter 83 provided with a calculation-control function, and the
inverter 83 is connected to the driving mechanism of the discharge
pump 63 and serves to frequency-control the number of rotations of
the discharge pump 63 on the basis of the pressure value measured
by the pressure gauge 43 on the inlet side. The outlet part of the
discharge pump 63 is connected through a flow meter 93 to another
storage tank 55 for storing vegetable-fruit products which have
been further concentrated by reverse osmosis.
[0030] Connected to this storage tank 55 through a valve is the
suction inlet part of a circulation pump 111 which is still another
single-axis eccentric screw pump. The discharge outlet of the
circulation pump 111 is connected to the storage tank 54. Thus, a
portion of the vegetable-fruit product stored in the storage tank
55 is returned to the tank 54 and processed again through the
downstream concentration unit 23 together with the incompletely
processed products from the upstream concentration unit 22.
[0031] The apparatus of FIG. 2 may be operated by rotating the
supply pump 32 at a constant rate and frequency-controlling the
number of rotations of the discharge pump 62 while supplying a
vegetable-fruit product from the storage tank 53 to the tubular
membrane modules 12 successively through the supply pump 32 and the
pressure gauge 42 on the inlet side. After it is concentrated
preliminarily through the concentration unit 22 with tubular
membrane modules 12 connected in series, it is passed successively
through the tubular membrane module 12 on the outlet side, the
pressure gauge 72 on the outlet side, the discharge pump 62 and the
flow rate meter 92 into the storage tank 54. The liquid which
permeated through the tubular semipermeable membranes supported by
the individual ones of the tubular membrane modules 12 during the
concentration process by reverse osmosis in the concentration unit
22 is collected in a receptacle 102 provided at the bottom of the
concentration unit 22.
[0032] While the supply pump 33 is rotated at a constant rate, the
number of rotations of the discharge pump 63 is
frequency-controlled, as explained above, and the preliminarily
concentrated product (or a mixture of the preliminarily
concentrated product and the returned portion from the tank 55)
from the storage tank 54 is supplied to the tubular membrane
modules 13 on the inlet side successively through the supply pump
33 and the pressure gauge 43 on the inlet side. After it is
concentrated by osmosis in the concentration unit 23 with a
plurality of tubular membrane unit 13 connected in series, the
concentrated product is stored in the tank 55 by successively
passing through the tubular membrane module 13 on the outlet side,
the pressure gauge 73 on the outlet side, the discharge pump 63 and
the flow rate meter 93. If necessary, a portion of the product
stored in the tank 55 is returned to the tank 54 by means of the
circulation pump 111. The liquid which permeated through the
tubular semipermeable membranes supported by the individual ones of
the tubular membrane modules 13 during the concentration process by
reverse osmosis in the concentration unit 23 is collected in
another receptacle 103 provided at the bottom of the concentration
unit 23.
[0033] In summary, the apparatus shown in FIG. 2 is operated by a
two-stage circulating process, causing a vegetable-fruit product to
flow down to the upstream concentration unit 22 and to the
downstream concentration unit 23 and returning a portion of the
concentrated product back to the inlet side of the downstream
concentration unit 23 through the circulation pump 111, if
necessary. If the circulation pump 111 is omitted, this becomes an
apparatus by a two-stage single-pass process.
[0034] The invention is described next by way of test and
comparison examples.
TEST EXAMPLE 1
[0035] The apparatus for a single-stage single-pass process shown
in FIG. 1 was used continuously for 5 hours to concentrate a tomato
product under the following conditions: [0036] Tomato product:
Product processed at 60.degree. C. with concentration 5.0% in Brix
scale obtained by peeling, cutting, heating and thereafter crushing
tomatoes and containing skins and meat parts as solid components by
35 weight % (the amount of the solid components being the ratio of
the residue obtained by passing through a sieve provided with a
filter wire with opening diameters of 2.8 mm); [0037] Concentration
unit: Unit with total membrane surface area of 10.4 m.sup.2 having
a plurality of tubular membrane modules connected in series, each
supporting a tubular semipermeable membrane (AFC99 produced by PCI
Inc.); [0038] Supply pump: Mohno-pump 8NES30 produced by Heishin
Engineering & Equipment Co., Ltd.; [0039] Discharge pump:
Mohno-pump 8NE30 produced by Heishin Engineering & Equipment
Co., Ltd.; [0040] Pressure on inlet side of concentration unit:
3.5-4.0 MPa; [0041] Pressure on outlet side of concentration unit:
1.5-2.0 MPa; [0042] Supply rate of vegetable-fruit product to
concentration unit: 400 liters/hour; [0043] Discharge rate from
concentration unit: 200 liters/hour.
[0044] There was no pulsating movement when the tomato product was
supplied to the concentration unit and there was no splashing or
absorption of air when concentrated product was discharged from the
concentration unit. The supply and discharge pumps were not clogged
by the solid components and concentrated products by reverse
osmosis containing solid components by 65 weight % and with
concentration of 10.0% in Brix scale, containing the solid
components approximately in the same forms as before the
concentration process were obtained. In other words, tomato
products containing solid components could be concentrated by
reverse osmosis by a stable operation and under an easy process
management and processed products containing solid components
approximately in their original forms could be obtained.
COMPARISON EXAMPLE 1
[0045] Tomato products were condensed intermittently for 5 hours by
reverse osmosis in the same manners as in Test Example 1 except a
plunger pump was used instead of the single-axis eccentric screw
pump as a supply pump, a pressure control valve was used instead of
the single-axis eccentric screw pump as the discharge pump and the
target inlet and outlet pressures for the concentration unit were
set respectively at 3.5-4.0 MPa and 1.5-2.0 MPa. The pulsating
motion at the time of supplying the tomato product to the
concentration unit was large and there was intense scattering and
absorption of air at the time of its discharge from the
concentration unit. The plunger pump and the pressure control valve
became clogged frequently with the solid components and the
apparatus were stopped each time for cleaning. As the concentration
operation was continued intermittently, the solid components were
cut and/or crushed and a concentrated product containing 20 weight
% of solid components not keeping their original forms and
concentration of 6.0% in Brix scale was obtained.
TEST EXAMPLE 2
[0046] The apparatus for a two-stage circulating process shown in
FIG. 2 was used continuously for 5 hours without circulating back
the concentrated product discharged from the second concentration
unit to concentrate an apple product by a two-stage single-pass
process under the following conditions: [0047] Apple product:
Product processed at 60.degree. C. with concentration 11.2% in Brix
scale obtained by removing peels, seeds and cores from apples,
crushing them while sprinkling an aqueous solution containing
Vitamin C and thereafter heating and cooling, containing apple meat
parts as solid components by 43 weight %; [0048] Concentration
unit: With a first unit with total membrane surface area of 7.8
m.sup.2 having a plurality of tubular membrane modules connected in
series, each supporting a tubular semipermeable membrane (AFC99
produced by PCI Inc.) and a second unit with total membrane surface
area of 5.2 m.sup.2 having a plurality of tubular membrane modules
connected in series, each supporting a tubular semipermeable
membrane (AFC99 produced by PCI Inc.); [0049] Supply pumps:
Mohno-pumps 8NES30 (for upstream) and 12NES30 (downstream) both
produced by Heishin Engineering & Equipment Co., Ltd.; [0050]
Discharge pumps: Mohno-pumps 8NE30 (upstream) and 12NE30
(downstream) both produced by Heishin Engineering & Equipment
Co., Ltd.; [0051] Pressure on inlet side of concentration unit:
3.5-4.0 MPa (first stage) and 5.0-6.0 MPa (second stage); [0052]
Pressure on outlet side of concentration unit: 2.5-3.0 MPa (first
stage) and 3.0-4.0 MPa (second stage); [0053] Supply rate of apple
product to concentration unit: 500 liters/hour (first stage) and
350 liter/hour (second stage); [0054] Discharge rate from
concentration unit: 350 liters/hour (first stage) and 240
liter/hour.
[0055] There was no pulsating movement when the apple product and
the product processed in the first stage were supplied to the
concentration units and there was no splashing or absorption of air
when concentrated product was discharged from the concentration
units. The supply and discharge pumps were not clogged by the solid
components and concentrated products by reverse osmosis containing
solid components by 60 weight % and with concentration of 18.1% in
Brix scale, containing the solid components approximately in the
same forms as before the concentration process were obtained. In
other words, apple products containing solid components could be
concentrated by reverse osmosis by a stable operation and under an
easy process management and processed products containing solid
components approximately in their original forms could be
obtained.
COMPARISON EXAMPLE 2
[0056] Apple products were condensed intermittently for 5 hours by
reverse osmosis in the same manners as in Test Example 2 except a
plunger pump was used instead of each of the single-axis eccentric
screw pumps serving as a supply pump, a pressure control valve was
used instead of each of the single-axis eccentric screw pumps
serving as the discharge pump and the target inlet and outlet
pressures for the concentration unit were set respectively at
3.5-4.0 MPa and 2.5-3.0 MPa (first stage) and 5.0-6.0 MPa and
3.0-4.0 MPa (second stage). The pulsating motion at the time of
supplying the apple product and processed product to the
concentration units was large and there was intense scattering and
absorption of air at the time of its discharge from each
concentration unit. The plunger pumps and the pressure control
valves became clogged frequently with the solid components and the
apparatus were stopped each time for cleaning. As the concentration
operation was continued intermittently, the solid components were
cut and/or crushed and a concentrated product containing 30 weight
% of solid components not keeping their original forms and
concentration of 15.0% in Brix scale was obtained.
TEST EXAMPLE 3
[0057] The apparatus for a two-stage circulating process shown in
FIG. 2 was used continuously for 5 hours without circulating back
the concentrated product discharged from the second concentration
unit to concentrate a strawberry product by a two-stage single-pass
process under the following conditions: [0058] Strawberry product:
Product with concentration 8.5% in Brix scale obtained by removing
stems from strawberries and thereafter crushing them, containing
seeds and meat parts as solid components by 28 weight %; [0059]
Concentration unit: With a first unit with total membrane surface
area of 5.2 m.sup.2 having a plurality of tubular membrane modules
connected in series, each supporting a tubular semipermeable
membrane (AFC99 produced by PCI Inc.) and a second unit with total
membrane surface area of 5.2 m.sup.2 having a plurality of tubular
membrane modules connected in series, each supporting a tubular
semipermeable membrane (AFC99 produced by PCI Inc.); [0060] Supply
pumps: Mohno-pumps 8NES30 (for upstream) and 12NES30 (downstream)
both produced by Heishin Engineering & Equipment Co., Ltd.;
[0061] Discharge pumps: Mohno-pumps 8NE30 (upstream) and 12NE30
(downstream) both produced by Heishin Engineering & Equipment
Co., Ltd.; [0062] Pressure on inlet side of concentration unit:
3.5-4.0 MPa (first stage) and 5.0-6.0 MPa (second stage); [0063]
Pressure on outlet side of concentration unit: 2.5-3.0 MPa (first
stage) and 3.0-4.0 MPa (second stage); [0064] Supply rate of apple
product to concentration unit: 500 liters/hour (first stage) and
400 liter/hour (second stage); [0065] Discharge rate from
concentration unit: 400 liters/hour (first stage) and 300
liter/hour.
[0066] There was no pulsating movement when the strawberry product
and the product processed in the first stage were supplied to the
concentration units and there was no splashing or absorption of air
when concentrated product was discharged from the concentration
units. The supply and discharge pumps were not clogged by the solid
components and concentrated products by reverse osmosis containing
solid components by 35 weight % and with concentration of 14.2% in
Brix scale, containing the solid components approximately in the
same forms as before the concentration process were obtained. In
other words, strawberry products containing solid components could
be concentrated by reverse osmosis by a stable operation and under
an easy process management and processed products containing solid
components approximately in their original forms could be
obtained.
COMPARISON EXAMPLE 3
[0067] Strawberry products were condensed intermittently for 5
hours by reverse osmosis in the same manners as in Test Example 3
except a plunger pump was used instead of each of the single-axis
eccentric screw pumps serving as a supply pump, a pressure control
valve was used instead of each of the single-axis eccentric screw
pumps serving as the discharge pump and the target inlet and outlet
pressures for the concentration unit were set respectively at
3.5-4.0 MPa and 2.5-3.0 MPa (first stage) and 5.0-6.0 MPa and
3.0-4.0 MPa (second stage). The pulsating motion at the time of
supplying the strawberry product and processed product to the
concentration units was large and there was intense scattering and
absorption of air at the time of its discharge from each
concentration unit. The plunger pumps and the pressure control
valves became clogged frequently with the solid components and the
apparatus were stopped each time for cleaning. As the concentration
operation was continued intermittently, the solid components were
cut and/or crushed and a concentrated product containing 20 weight
% of solid components not keeping their original forms and
concentration of 12.0% in Brix scale was obtained.
[0068] The disclosure given above makes it clear that the present
invention makes it possible to concentrate even vegetable and/or
fruit products containing solid components by osmosis such that
concentrated product containing solid components approximately in
their original forms can be obtained.
* * * * *