Sealed reagent sleeve and pressure differential BOD measuring instrument and sealing detection method thereof

Abstract

The present invention discloses a sealed reagent sleeve and a pressure differential BOD measuring instrument and a sealing detection method thereof, relating to the technical field of environmental water pollution detection. The sealed reagent sleeve of the present invention comprises a reagent sleeve body, one end of which is provided with an outer flange, the upper end surface of which is provided with an annular first groove, a sealing ring is provided in the first groove, a wedge-shaped sealing ring is provided on the reagent sleeve body, and the wedge-shaped sealing ring is squeezed and arranged between the inner side of the culture bottle mouth and the reagent sleeve body, the interior of the reagent sleeve body is provided with a cavity, and an absorption reaction reagent is placed in the cavity, the first end of the cavity is open, the first end of the cavity is located at the outer flange, and the second end of the cavity is a blind end, and the side wall of the reagent sleeve body is provided with a plurality of through holes, and the plurality of through holes are connected to the cavity. The sealed reagent sleeve of the present invention has good sealing performance.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental water pollution detection, in particular to a sealed reagent sleeve and a pressure differential BOD measuring instrument and a sealing detection method thereof. Background Art

[0002] Biochemical oxygen demand (BOD) is a comprehensive indicator of the degree of organic pollution and the purification efficiency of biochemical treatment processes. It represents the amount of dissolved oxygen consumed by microbial oxidation of organic matter in water. Common methods for measuring BOD include the dilution inoculation method, the microbial sensor method, and the differential pressure method. The differential pressure method measures the negative pressure drop created by the oxygen consumed by microorganisms as they oxidize and decompose organic matter in a BOD culture bottle under a specific temperature. This pressure drop is then used to calculate the BOD concentration in the water sample. The principle is as follows: a water sample and inoculum solution are mixed in the required proportions and added to a culture bottle, which is sealed between a test cap. The test cap then measures pressure changes in the bottle. As microorganisms decompose organic matter in the water sample, they begin to consume dissolved oxygen, causing a decrease in the oxygen partial pressure in the air above the bottle. A higher reading on the test cap indicates a higher BOD value. Furthermore, as microorganisms oxidize and decompose organic matter in the water sample, they release carbon dioxide into the air above the bottle. An absorption reagent is required to absorb this carbon dioxide, and a good seal must be maintained between the bottle and the test cap to ensure accurate measurement results. The biochemical oxygen demand (BOD) is generally represented by the oxygen consumption of the water sample at 20°C over five days. This is referred to as the five-day BOD5.

[0003] The existing technology uses a reagent sleeve for sealing between the culture bottle and the test cap. The reagent sleeve is made of rubber material as a whole. The rubber material is relatively soft and easy to deform. During the process of tightening the test cap and the culture bottle, the outer flange of the reagent sleeve plays a sealing role. The upper end face of the outer flange contacts and rubs with the test cap, and the lower end face of the outer flange rubs with the bottle mouth of the culture bottle. Due to the large contact area and high friction between the outer flange and the test cap, the reagent sleeve will be twisted and deformed during the process of tightening the test cap and the culture bottle, resulting in a loose seal. Moreover, after tightening the test cap and the culture bottle, if the reagent sleeve is not sealed tightly, the user will not be able to find it. Summary of the Invention

[0004] In view of the problems existing in the prior art, the purpose of the present invention is to provide a sealed reagent sleeve and a pressure differential BOD measuring instrument and a sealing detection method thereof, which can effectively improve the overall airtightness.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention discloses a sealed reagent cover, comprising a reagent cover body, wherein one end of the reagent cover body is provided with an outer flange, the upper end surface of the outer flange is provided with an annular first groove, a sealing ring is provided in the first groove, a wedge-shaped sealing ring is sleeved on the reagent cover body, the wedge-shaped sealing ring is squeezed and arranged between the inner side of the bottle mouth of the culture bottle and the reagent cover body, a cavity is provided inside the reagent cover body, an absorption reaction reagent is placed in the cavity, a first end of the cavity is open, the first end of the cavity is located at the outer flange, and the second end of the cavity is a blind end, and a plurality of through holes are provided on the side wall of the reagent cover body, and the plurality of through holes are all connected to the cavity.

[0007] Preferably, a second groove is provided at the connection between the outer side surface of the reagent cover body and the lower end surface of the outer flange, and the inner side surface of the wedge-shaped sealing ring is clamped in the second groove. The two ends of the wedge-shaped sealing ring are respectively a large end and a small end, and the diameter of the large end is larger than the diameter of the small end.

[0008] Preferably, a conical surface is provided between the large end and the small end for transition connection.

[0009] Preferably, the reagent sleeve body and the outer flange are both made of hard plastic, and the wedge-shaped sealing ring is made of rubber.

[0010] Preferably, the sealing ring is an O-ring.

[0011] Preferably, the through holes are evenly distributed along the circumferential direction on the side wall of the reagent cover body, and the number of the through holes is 4.

[0012] Preferably, the through hole is located in the middle of the reagent sleeve body.

[0013] The present invention also discloses a pressure differential BOD measuring instrument, which includes a culture bottle, a test cap, a magnetic stirrer and a sealed reagent sleeve. The sealed reagent sleeve is arranged between the culture bottle and the test cap. The culture bottle is threadedly connected to the test cap and presses the sealed reagent sleeve. The sealed reagent sleeve is used for sealing between the culture bottle and the test cap. The magnetic stirrer is arranged at the bottom of the culture bottle.

[0014] The present invention also discloses a method for detecting the sealing performance of a BOD measuring instrument using a pressure differential method, comprising the following steps:

[0015] a. Insert the wedge-shaped sealing ring of the sealing reagent set into the mouth of the culture bottle, and then a portion of the wedge-shaped sealing ring enters the mouth of the culture bottle;

[0016] b. Tighten the test cap onto the culture bottle. During this process, the wedge-shaped sealing ring will be completely squeezed into the bottle mouth. The gas pressure in the culture bottle will increase. After tightening the test cap and the culture bottle, record the pressure value S1 displayed on the test cap.

[0017] c. Let the test cap stand for 5 to 10 minutes, then record the pressure value S2 displayed on the test cap again and compare it with the pressure value S1. If S1 > S2, tighten the test cap and culture bottle or replace the wedge-shaped sealing ring and sealing ring. If S1 = S2, the culture bottle and test cap are tightly sealed.

[0018] Compared with the prior art, the present invention has achieved the following technical effects:

[0019] The sealing ring is pressed against the inner surface of the bottle mouth of the culture bottle and the main body of the reagent sleeve, so that the wedge-shaped sealing ring is in extrusion contact with the inner surface of the bottle mouth of the culture bottle and the main body of the reagent sleeve to form a good seal, and the wedge-shaped sealing ring will not rotate to cause deformation of the sealing reagent sleeve. The sealing effect of the sealing ring and the wedge-shaped sealing ring makes the test cap and the culture bottle tightly sealed. The main body of the reagent sleeve and the outer flange are both made of hard plastic material. The hard plastic material is relatively hard and not easy to deform, which can avoid the deformation of the sealing reagent sleeve and the poor sealing during the tightening of the test cap and the culture bottle. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 This is a schematic structural diagram of the main body and outer flange of the sealed reagent sleeve of the present invention;

[0022] Figure 2 for Figure 1 sectional view of

[0023] Figure 3 is a cross-sectional view of the sealed reagent sleeve of the present invention;

[0024] Figure 4 is a cross-sectional view of a wedge-shaped sealing ring of the present invention;

[0025] Figure 5 Schematic diagram of the structure of the differential pressure BOD measuring instrument of the present invention;

[0026] Figure 6 for Figure 5 Enlarged view of part A in the middle.

[0027] Among them: 1-reagent set body; 11-second groove; 2-outer flange; 21-first groove; 3-through hole; 4-cavity; 5-wedge-shaped sealing ring; 51-large end; 52-conical surface; 53-small end; 6-sealing ring; 7-culture bottle; 8-test cap; 10-sealed reagent set; 20-differential pressure BOD measuring instrument. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] The purpose of the present invention is to provide a sealed reagent sleeve and a pressure differential BOD measuring instrument and a sealing detection method thereof, so as to solve the problems existing in the above-mentioned prior art and effectively improve the overall airtightness.

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] like Figure 1-4As shown, this embodiment provides a sealed reagent cover 10, including a reagent cover body 1, one end of which is provided with an outer flange 2, which is located at the upper end of the reagent cover body 1, and the outer flange 2 and the reagent cover body 1 are an integral structure. A first circular groove 21 is provided on the upper end surface of the outer flange 2, and a sealing ring 6 is provided in the first groove 21. The sealing ring 6 is used to seal the gap between the test cap 8 and the outer flange 2. A wedge-shaped sealing ring 5 is provided on the reagent cover body 1, and the wedge-shaped sealing ring 5 is squeezed and arranged between the inner side of the bottle mouth of the culture bottle 7 and the reagent cover body 1. The wedge-shaped sealing ring 5 is used to ensure the sealing between the outer wall of the reagent cover body 1 and the culture bottle 7. A cavity 4 is provided inside the reagent cover body 1, and an absorption reaction reagent is placed in the cavity 4. The absorption reaction reagent can be solid sodium hydroxide or potassium hydroxide. The first end of cavity 4 is open and located at outer flange 2, forming an annular structure. The second end of cavity 4 is a blind end, adjacent to the lower end of reagent cover body 1. Both cavity 4 and reagent cover body 1 are cylindrical structures. Several through-holes 3 are defined in the sidewalls of reagent cover body 1, each of which communicates with cavity 4. The amount of absorbed reaction reagent does not exceed the height of the through-holes 3 to prevent leakage.

[0032] During use, the lower end of the reagent cover body 1 is first inserted into the mouth of a culture bottle 7. The body 1 is gradually extended into the culture bottle 7 until the wedge-shaped sealing ring 5 contacts the mouth of the culture bottle 7. Then, a test cap 8 is fastened, threadedly connected to the outer side of the mouth of the culture bottle 7. As the test cap 8 is tightened, the wedge-shaped sealing ring 5 continuously compresses the culture bottle 7 until a seal is formed between the reagent cover body 1 and the culture bottle 7. Furthermore, the test cap 8 gradually approaches the sealing ring 6 located on the upper end surface of the outer flange 2, thereby achieving a seal between the test cap 8 and the outer flange 2. At this point, the gas in the culture bottle 7 enters the cavity 4 through the through hole 3. The carbon dioxide in the gas is then absorbed by the absorption reaction reagent. Finally, the gas flows from the first end (opening) of the cavity 4 into the test cap 8 for measurement.

[0033] In order to realize the setting of the wedge-shaped sealing ring 5, in this embodiment, an annular second groove 11 is provided at the connection between the outer side surface of the reagent cover body 1 and the lower end surface of the outer flange 2. The inner side surface of the wedge-shaped sealing ring 5 is snapped into the second groove 11. The two ends of the wedge-shaped sealing ring 5 are respectively a large end 51 and a small end 53. The diameter of the large end 51 is larger than the diameter of the small end 53, and the inner diameter of the large end 51 is smaller than the inner diameter of the small end 53. The inner ring of the large end 51 is snapped into the second groove 11, and the large end 51 is higher than the small end 53. As for the specific dimensions of the wedge-shaped sealing ring 5: the inner diameter of the large end 51 is 13.2mm; the inner diameter of the small end 53 is the same as the outer wall diameter of the reagent cover body 1, both of which are 14.4mm; the outer diameter of the small end 53 is 17.6mm, the outer diameter of the large end 51 is 20mm, and the overall height of the wedge-shaped sealing ring 5 is 3.5mm.

[0034] Furthermore, in this embodiment, a conical surface 52 is provided between the large end 51 and the small end 53 for transition connection. During use, the conical surface 52 abuts against the bottle mouth of the culture bottle 7, and the diameter of the conical surface 52 gradually decreases from top to bottom to facilitate the wedge-shaped sealing ring 5 to enter the culture bottle 7.

[0035] In this embodiment, the reagent sleeve body 1 and outer flange 2 are both made of hard plastic, and the wedge-shaped sealing ring 5 is made of rubber. Hard plastic is relatively hard and less prone to deformation, thus preventing deformation of the sealed reagent sleeve 10 and resulting in a poor seal during tightening of the test cap 8 and the culture bottle 7.

[0036] As for the type of the sealing ring 6 , in this embodiment, the sealing ring 6 is an O-ring. Those skilled in the art may also select other types of sealing rings 6 according to actual needs.

[0037] As for the distribution of the through holes 3, in this embodiment, the through holes 3 are evenly distributed along the circumferential direction on the side wall of the reagent cover body 1, the number of the through holes 3 is 4, and the diameter of the through holes 3 is 5 mm.

[0038] Furthermore, in this embodiment, the through hole 3 is located in the middle of the reagent cover body 1. Specifically, the distance from the outer flange 2 to the lower end of the reagent cover body 1 is 36.5 mm, and the distance from the through hole 3 to the lower end of the reagent cover body 1 is 19 mm.

[0039] This embodiment also provides a pressure differential BOD measuring instrument 20, which includes a culture bottle 7, a test cap 8, an electromagnetic stirrer and a sealed reagent sleeve 10. The sealed reagent sleeve 10 is arranged between the culture bottle 7 and the test cap 8. The outer wall of the bottle mouth of the culture bottle 7 is provided with an external thread, and the test cap 8 has an internal thread. The culture bottle 7 and the test cap 8 are threadedly connected and tightly press the sealed reagent sleeve 10. The sealed reagent sleeve 10 is used for sealing between the culture bottle 7 and the test cap 8. The electromagnetic stirrer is arranged at the bottom of the culture bottle 7 and can stir the reagent in the culture bottle 7.

[0040] This embodiment also provides a method for detecting the sealing performance of a pressure differential BOD measuring instrument 20, comprising the following steps:

[0041] a. The wedge-shaped sealing ring 5 of the sealing reagent sleeve 10 is inserted into the mouth of the culture bottle 7, at which point a portion of the wedge-shaped sealing ring 5 enters the mouth of the culture bottle 7;

[0042] b. Tighten the test cap 8 onto the culture bottle 7. During this process, the wedge-shaped sealing ring 5 is completely squeezed into the mouth of the culture bottle 7. The gas pressure in the culture bottle 7 will rise. After tightening the test cap 8 and the culture bottle 7, record the pressure value S1 displayed on the test cap 8.

[0043] c. Let it stand for 5 to 10 minutes, record the pressure value S2 displayed on the test cap 8 again, and compare the pressure value S2 with the pressure value S1. If S1>S2, it means that the sealing effect is not good and there is leakage. You need to retighten the test cap 8 and the culture bottle 7 or replace the wedge-shaped sealing ring 5 and the sealing ring 6. If S1=S2, it means that the culture bottle 7 and the test cap 8 are tightly sealed.

[0044] This specification uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A method for detecting the sealing performance of a BOD measuring instrument using a differential pressure method, characterized in that: The following steps are involved: a. Insert the wedge-shaped sealing ring of the sealing reagent set into the mouth of the culture bottle, and then a portion of the wedge-shaped sealing ring enters the mouth of the culture bottle; b. Tighten the test cap onto the culture flask. During this process, the wedge-shaped sealing ring squeezes into the flask's opening, causing the gas pressure inside the flask to rise. After tightening the test cap onto the flask, record the pressure value S1 displayed on the test cap. c. Let it stand for 5 to 10 minutes, then record the pressure value S2 displayed on the test cap again and compare it with the pressure value S1. If S1 > S2, you need to retighten the test cap and the culture bottle or replace the wedge-shaped sealing ring and the sealing ring. If S1 = S2, the culture bottle and the test cap are tightly sealed. The sealed reagent cover comprises a reagent cover body, one end of the reagent cover body is provided with an outer flange, the upper end surface of the outer flange is provided with an annular first groove, a sealing ring is provided in the first groove, a wedge-shaped sealing ring is sleeved on the reagent cover body, the wedge-shaped sealing ring is squeezed and arranged between the inner side of the bottle mouth of the culture bottle and the reagent cover body, a cavity is provided inside the reagent cover body, an absorption reaction reagent is placed in the cavity, a first end of the cavity is open, the first end of the cavity is located at the outer flange, and the second end of the cavity is a blind end, and a plurality of through holes are provided on the side wall of the reagent cover body, and the plurality of through holes are connected to the cavity; A second groove is provided at the connection between the outer side surface of the reagent cover body and the lower end surface of the outer flange, and the inner side surface of the wedge-shaped sealing ring is clamped in the second groove. The two ends of the wedge-shaped sealing ring are respectively a large end and a small end, and the diameter of the large end is larger than the diameter of the small end.

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