CN107410822A - A kind of common field process chamber of the high-pressure pulse electric sterilization system based on fluid behaviour optimization - Google Patents

Abstract

The present invention relates to a kind of common field process chamber of the high-pressure pulse electric sterilization system based on fluid behaviour optimization, the metal hollow tubulose high-field electrode of the common field process chamber, the internal cavities of metal hollow tubular grounding electrode have certain taper, geometry is round table-like, the internal protrusion of insulator isolated tube is ellipse, comparatively ideal flow field can not only be obtained in material processing region, electric field distribution characteristic, and more uniform velocity flow profile can obtained at material outlet, solve the problems, such as in ordinary electrode inner chamber as inlet flow rate improves or chamber size increases and causes exit velocity flow profile uneven, be advantageous to multiprocessing room tandem compound to use, to improve sterilization processing efficiency.The treatment effeciency of the common field process chamber can meet the application requirement of Commercial scale, have the advantages that function admirable, it is compact-sized, be applied in combination convenient, provide possibility for the commercial applications of high-pressure pulse electric sterilization.

Description

Common field of a high-voltage pulsed electric field sterilization system based on optimization of fluid characteristics management room

technical field

The invention relates to a common-field treatment chamber of a high-voltage pulse electric field sterilization system, in particular to a common-field treatment chamber of a high-voltage pulse electric field sterilization system based on fluid characteristic optimization.

Background technique

With the improvement of living standards, people's demand for food quality is increasing. In order to maintain the minimum loss of food sensory and nutritional value, non-thermal sterilization technology has been widely used in food processing. High-voltage pulsed electric field (PEF) sterilization technology is one of the most promising non-thermal sterilization technologies for industrial development. PEF sterilization has The sterilization effect is good, generally can reduce 6 logarithmic cycles, the sterilization time is short, the sterilization temperature rise is low, the chemical composition, appearance and flavor of the food are basically not affected, the energy consumption is small, and there is basically no pollution to the environment. A complete PEF sterilization system mainly includes four parts: high-voltage pulse generator, treatment chamber, fluid treatment system and monitoring auxiliary system. The treatment chamber is an important part of the PEF sterilization system, which is used to load the materials to be treated and store the electrodes, and directly apply a high-voltage pulsed electric field in the treatment chamber. The processing chamber generally consists of two electrodes and an insulating material for mounting the electrodes. According to whether the material flows, the processing chamber is divided into static type and continuous type; according to the electrode form, it is divided into three types: flat type, coaxial type and common field type.

The problems existing in the existing treatment chamber mainly include: (1) The flow velocity in the treatment chamber is fast in the middle and the boundary is slow, resulting in uneven flow velocity, and partial material retention leads to incomplete treatment, and as the inlet flow velocity and the size of the treatment chamber increase, the The inhomogeneity of the fluid velocity in the electrode is intensified; (2) The distribution of the electric field intensity is unreasonable, the electric field intensity near the electrode rises sharply, and there is a peak electric field, and the local electric field is too high may cause discharge problems; (3) The sterilizing effect of a single treatment chamber limited, and the processing capacity is also restricted by the size of the structure.

Judging from the existing technologies, the design of the current processing chamber is mostly limited to the laboratory scale, and there is a big gap from the commercial processing requirements. In order to improve the coupling field characteristics of the treatment chamber, the Chinese invention patent No. 201110359035.0 discloses a common field treatment chamber based on a high-voltage pulsed electric field sterilization system based on the optimization of the coupling field structure. The improvement lies in the use of an ellipse embedded common field treatment The structure of the chamber has better characteristics of the electric field, flow field and temperature field in the material processing area. There is still a relatively large material stagnation area at the material outlet of the processing chamber unit, resulting in an uneven distribution of flow velocity in the entire fluid system, which is not conducive to commercial application.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art, and provide a co-field treatment chamber based on a high-voltage pulsed electric field sterilization system optimized for fluid properties.

The technical solution steps that the present invention takes are as follows:

A common-field treatment chamber of a high-voltage pulsed electric field sterilization system based on optimization of fluid characteristics is composed of an inlet conduit, an outlet conduit, a metal hollow tubular high-voltage electrode, an insulator isolation tube, a metal hollow tubular ground electrode, a sealing nut, a ferrule and Composed of sealing rings, the insulator isolation tube is located between the metal hollow tubular high-voltage electrode and the metal hollow tubular ground electrode to form a processing chamber.

Both the metal hollow tubular high-voltage electrode and the metal hollow tubular grounding electrode have a certain taper in their internal cavities, and the geometric shape is a truncated cone. The taper of this truncated cone-shaped cavity is ≥ 7:100. The end faces of the two smaller apertures are separated from the insulator. The hole sides of the tube fit snugly. All electrodes and insulator isolation tubes are threaded and sealed with seals to prevent liquid leakage.

The inner diameter of the large end of the frustum-shaped cavity of the metal hollow tubular high-voltage electrode and the metal hollow tubular ground electrode is 2 mm to 14 mm, and the length of the major axis of the elliptical protrusion of the insulator isolation tube is close to or equal to this distance.

Compared with the prior art, the present invention has the advantage that: when the co-field sterilization treatment chambers are combined in series, better fluid characteristics can be obtained, which solves the problem of increasing the inlet flow rate or the size of the treatment chamber in the common electrode cavity. The problem of uneven flow velocity distribution at the outlet is caused, which avoids the phenomenon of incomplete treatment caused by material retention under the condition of large processing capacity. The distribution of electric field intensity in the treatment chamber is also reasonable, and ideal sterilization treatment efficiency can be obtained. Therefore, the treatment chamber can meet the application requirements of commercial scale, and has the advantages of excellent performance, compact structure, convenient combination and use, etc., which provides the possibility for the commercial application of high-voltage pulsed electric field sterilization.

Description of drawings

Fig. 1 is a schematic cross-sectional view of a single processing chamber unit of the present invention;

Fig. 2 is the schematic diagram of the series combination of multi-processing chamber units of the present invention;

Fig. 3 is the electric field intensity distribution diagram inside the treatment chamber of the present invention;

Fig. 4 is the flow field distribution diagram of the co-field treatment chamber without taper inside the electrode;

Fig. 5 is a flow field distribution diagram of the co-field processing chamber of the present invention.

Explanation of reference signs: 1—feed inlet conduit, 2—feed outlet conduit, 3—metal hollow tubular high-voltage electrode, 4—insulator isolation tube, 5—metal hollow tubular ground electrode, 6—sealing nut, 7—ferrule , 8—sealing ring.

detailed description

The present invention will be further described below in conjunction with specific drawings and embodiments.

As shown in Figure 1, the co-field treatment chamber of a high-voltage pulsed electric field sterilization system based on fluid characteristic optimization provided by the present invention consists of a feed inlet conduit (1), a discharge outlet conduit (2), a metal hollow tubular high-voltage electrode ( 3), an insulator isolation tube (4), a metal hollow tubular grounding electrode (5), a sealing nut (6), a ferrule (7) and a sealing ring (8). The insulator isolation tube (4) is located between the metal hollow tubular high-voltage electrode (3) and the metal hollow tubular ground electrode (5) to form a processing chamber. Both the metal hollow tubular high-voltage electrode (3) and the metal hollow tubular grounding electrode (5) have a certain taper in their internal cavities, and the geometric shape is frustum-shaped. The taper of the frustum-shaped cavity inside the electrode is ≥ 7:100. The smaller end faces are in close contact with both sides of the hole of the insulator isolation tube (4), and the electrode with this shape and structure can obtain better flow field distribution characteristics, avoiding incomplete material treatment caused by uneven flow velocity distribution. All metal electrodes and insulator isolation tubes (4) are threaded and sealed by sealing rings (8) to prevent liquid leakage.

Figure 2 is a schematic diagram of a series combination of multi-processing chamber units of the present invention. The conduits are connected to the corresponding metal electrodes through sealing nuts (6) and ferrules (7), and several processing chamber units are connected end-to-end through these conduits to form a series combination structure. This method of combining multiple treatment chambers in series can break the situation that a single treatment chamber unit has limited sterilizing ability, and has strong practicability.

The insulator isolation tube (4) is made of polytetrafluoroethylene material, and the convex geometry of its inner hole is oval. The metal hollow tubular high-voltage electrode (3) and the metal hollow tubular ground electrode (5) are made of stainless steel 316L. The inner diameter of the large end of their frustum-shaped cavity is 2 mm to 14 mm, and the length of the elliptical protrusion of the insulator isolation tube (4) The axis length is close to or equal to this spacing. Figure 3 is the distribution diagram of the electric field intensity inside the processing chamber. It can be seen that the electric field intensity distribution in the common field processing chamber is relatively uniform, there is no peak electric field near the electrodes, and the high-intensity electric field is concentrated in the processing area, so the electric field intensity distribution ideal.

Fig. 4 and Fig. 5 are the flow field distribution diagram of the common field treatment chamber without taper inside the electrode and the flow field distribution diagram of the common field treatment chamber of the present invention respectively. During the simulation process of the model of the processing chamber, the inlet flow velocity of 0.982m/s is consistent. For the common field treatment chamber with no internal taper, an electrode with an inner diameter of 6 mm is used. As shown in Figure 4, there is a large material retention area inside the metal electrode cavity near the discharge port, that is, the area with a lower flow rate in the figure. And as shown in the simulation result of Fig. 5, the co-field processing chamber of the present invention adopts the electrode with the inner diameter of the large end of the conical cavity of 6 mm, and there is no large-area material retention area in the metal electrode cavity near the discharge port. So the velocity distribution is more reasonable. Therefore, when the multi-processing chamber units are combined in series as shown in Figure 2, the material system as a whole can obtain better flow field distribution characteristics, avoid the phenomenon of incomplete sterilization, and improve the sterilization efficiency.

Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore The scope of protection of the present invention should be defined by the claims.

Claims (4)

1. A co-field treatment chamber of a high-voltage pulsed electric field sterilization system based on fluid characteristic optimization, which consists of a feed inlet conduit (1), a discharge outlet conduit (2), a metal hollow tubular high-voltage electrode (3), and an insulator isolation tube (4), metal hollow tubular grounding electrode (5), sealing nut (6), ferrule (7) and sealing ring (8), the insulator isolation tube (4) is located between the metal hollow tubular high voltage electrode (3) and the metal hollow A processing chamber is formed between the tubular ground electrodes (5), which is characterized in that: the metal hollow tubular high-voltage electrode (3) and the inner cavity of the metal hollow tubular ground electrode (5) have a certain taper, and the geometric shape is a conical shape. The end faces with smaller apertures are in close contact with both sides of the hole of the insulator isolation tube (4), and all electrodes and the insulator isolation tube (4) are threadedly connected and sealed by a sealing ring (8) to prevent liquid leakage. 2. The co-field processing chamber according to claim 1, characterized in that: the taper of the frustum-shaped cavities inside all electrodes is ≥7:100. 3. The co-field processing chamber according to claim 1-2, characterized in that the inner diameter of the large end of the frustum-shaped cavity of the metal hollow tubular high-voltage electrode (3) and the metal hollow tubular ground electrode (5) is 2 mm to 14 mm. 4. The co-field processing chamber according to claim 1-2, characterized in that the length of the major axis of the elliptical protrusion of the insulator isolation tube (4) is close to or equal to the inner diameter of the large end of the frustum-shaped cavity of the electrode.