An enhanced electro-flocculation coupling reaction device for heavy metal wastewater treatment

Abstract

The invention discloses an enhanced electric flocculation coupling reaction device for heavy metal wastewater treatment, which includes a primary treatment unit and a secondary treatment unit. In the primary treatment unit, under aeration conditions, tiny bubbles and water flow are kept to dynamically flush the surface of the electrode plate with a certain intensity to reduce the adhesion of pollutants on the surface of the electrode plate. The tiny bubbles generated by bottom aeration have a cleaning effect on the electrode plate, reducing the phenomenon of passivation of the electrode plate caused by the adhesion of organic matter. In the secondary treatment unit, the tiny bubbles generated by bottom aeration have a cleaning effect on the microfiltration membrane group. During cleaning and maintenance, a cleaning medium (water or gas) can be introduced into the water vapor cleaning port by using a cleaning device, so as to clean the inner cavity of the secondary treatment box and the microfiltration membrane group arranged therein. These measures can strengthen the electric flotation effect, improve the flocculation sedimentation conditions, and ensure the long-term stable operation of the electric flocculation device.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, in particular to an enhanced electric flocculation coupling reaction device used for heavy metal wastewater treatment. Background Art

[0002] Electrocoagulation (EC) technology has a 130-year history of development. It is an environmentally friendly water treatment process that combines the characteristics of chemical flocculation and electrochemical technology. Since the introduction of electrocoagulation technology, it has been promoted and applied to a certain extent. Influenced by electrochemical theory, the development of the power industry and traditional chemical flocculants, it has been paid attention to again in the 21st century and has become a hot research direction in water treatment technology.

[0003] Electrocoagulation technology has some inherent disadvantages: 1) The conductivity requirement is high, and the solution must have a high conductivity, which is more suitable for industrial wastewater (electroplating wastewater, printing and dyeing wastewater, catering wastewater and papermaking wastewater, etc.); 2) The anode needs to be replaced regularly. The anode is electrochemically dissolved, and a large amount of consumption will occur during long-term operation, so it needs to be replaced regularly; 3) Metal ion residues. Metal ions are dissolved during the electrocoagulation process. In addition to generating electrocoagulants, some metal ions are dissolved in the water, such as iron ions and aluminum ions. Residual; 4) Anode passivation. The passivation film causes the anode dissolution rate to slow down, the current efficiency to decrease, and the operating power consumption to increase.

[0004] Based on the above problems, the research on electrocoagulation technology has gradually developed from "traditional electrocoagulation" to "enhanced electrocoagulation", which not only ensures the efficient removal of pollutants, but also alleviates electrode passivation and reduces energy consumption.

[0005] Flocculation technology plays an irreplaceable role in water pollution control and is an indispensable part of the treatment and disposal of various water bodies. Enhanced Coagulation is a process in which the removal rate of organic matter is improved by increasing the dosage of flocculants while ensuring the turbidity removal effect during the conventional flocculation process of water treatment, that is, the strengthening and optimization of any one or more links of reagents, mixing, coagulation and flocculation to further improve the purification effect of pollutants in water. In the current research in the field of electroflocculation, there is no clear definition of "enhanced electroflocculation". Dai Changchao and others refer to the definition of enhanced flocculation and understand enhanced electrocoagulation as strengthening or optimizing any one or several links of electrocoagulation, electroflotation, electrooxidation and electroreduction in traditional electroflocculation technology, so as to clarify the strengthening and optimization goals and directions of electroflocculation technology, which has certain technical guiding significance.

[0006] During the electrocoagulation process, gas is generated to form tiny bubbles on the surface of the electrode. When the bubbles reach a certain amount, flotation occurs. Due to the amount of bubbles and the generation rate, the electroflotation effect of traditional electrocoagulation reactors is limited. Summary of the invention

[0007] The purpose of the present invention is to provide an enhanced electric flocculation coupling reaction device for heavy metal wastewater treatment to enhance the electric flotation effect, improve the flocculation sedimentation conditions, and ensure the long-term stable operation of the electric flocculation device.

[0008] The object of the present invention is achieved as follows: an enhanced electric flocculation coupling reaction device for heavy metal wastewater treatment comprises a primary treatment unit, the primary treatment unit comprises a primary treatment box, a primary metering pump, and an electrode plate group, the bottom of the inner cavity of the primary treatment box is set as a raw water collection area, the electrode plate group is arranged in the inner cavity of the primary treatment box and is located above the raw water collection area, and the infusion end of the primary metering pump is connected to the raw water collection area;

[0009] A first demister is installed on the top wall of the primary treatment box, and the filtering part of the first demister is located at the top of the inner cavity of the primary treatment box;

[0010] The first treatment box inner cavity is provided with a first-level upper liquid collecting area located above the electrode plate group, and is also provided with an upper liquid storage chamber parallel to the first-level upper liquid collecting area, an overflow channel communicating with the upper side of the upper liquid storage chamber is provided on the upper side of the first-level upper liquid collecting area, and the filtering part of the first demister is located in the overflow channel of the first-level upper liquid collecting area;

[0011] A first aeration port connected to the raw water collection area is provided at the bottom of the primary treatment box, and the first aeration port faces the electrode plate group upward.

[0012] Furthermore, a defoaming layer for filtering out floating foam is provided in the upper liquid storage chamber and is located below the overflow channel of the first-level upper liquid collecting area. A water storage tank is also provided on the outer side wall of the first-level treatment tank. The water storage tank is provided with a first cavity and a second cavity arranged side by side on the left and right. The upper liquid storage chamber has an overflow port located below the defoaming layer and connected to the upper side of the first cavity. An overflow channel leading from the first cavity to the second cavity is provided in the water storage tank.

[0013] Furthermore, it also includes a secondary processing unit, and the secondary processing unit includes:

[0014] A secondary treatment box, wherein a solid-liquid separation component is provided in the inner cavity of the secondary treatment box, an area below the solid-liquid separation component in the inner cavity of the secondary treatment box is set as a secondary collection area, an area above the solid-liquid separation component is set as an upper liquid collection area, and an overflow port is provided on the upper side of the secondary treatment box;

[0015] A secondary metering pump, wherein the suction end of the secondary metering pump is connected to the bottom of the second cavity of the water storage tank, and the water outlet end of the secondary metering pump is connected to the secondary collecting area;

[0016] A second demister for filtering out floating foam in overflow water in the secondary treatment tank, wherein the second demister is arranged on the top wall of the secondary treatment tank and a filtering part thereof is located at the top of the inner cavity of the secondary treatment tank;

[0017] The overflow liquid collecting bin is fixedly arranged on the outer side wall of the secondary treatment box, the upper side of the overflow liquid collecting bin is connected with the upper overflow port of the secondary treatment box, and the bottom of the overflow liquid collecting bin is provided with a bottom water outlet.

[0018] Furthermore, the solid-liquid separation component in the secondary treatment box is configured as at least one group of microfiltration membrane groups, and the microfiltration membrane group is composed of a plurality of microfiltration membranes that are spaced apart and close to each other in the horizontal direction.

[0019] Furthermore, a second aeration port connected to the secondary collection area and facing upwards to the microfiltration membrane group is provided at the bottom of the secondary treatment box.

[0020] Furthermore, the secondary treatment unit is also provided with a self-priming pump, the water suction end of the self-priming pump is connected to the water outlet end of the microfiltration membrane group in the inner cavity of the secondary treatment box;

[0021] The bottom of the primary treatment tank is provided with a first dosing port which is in communication with the raw water collection area;

[0022] The water outlet of the self-priming pump is divided into at least two outputs, and one of the output pipelines is connected to the inner cavity of the primary treatment box through the first dosing port.

[0023] Furthermore, a plurality of water vapor cleaning ports connected to cleaning equipment are provided on the top of the secondary processing box, and the water vapor cleaning ports are connected to the inner cavity of the secondary processing box.

[0024] Furthermore, the side wall of the secondary treatment box is provided with at least one side return port, the position of the side return port is lower than the position of the second demister, and the side return port connects the overflow liquid collecting bin and the upper liquid collecting area to drain part of the water in the overflow liquid collecting bin to the upper liquid collecting area.

[0025] Furthermore, a first mud discharge port for discharging sludge is provided at the bottom of the primary treatment tank, and a second mud discharge port for discharging sludge is provided at the bottom of the secondary treatment tank.

[0026] Furthermore, a second drug adding port communicating with the secondary collecting area is provided at the bottom of the secondary treatment box.

[0027] The beneficial effects of the present invention are:

[0028] 1. In the primary treatment unit, under aeration conditions, keep the tiny bubbles and water flow at a certain intensity to dynamically flush the surface of the electrode plate, reduce the adhesion of pollutants on the surface of the electrode plate, and the tiny bubbles generated by the bottom aeration have a cleaning effect on the electrode plate, reducing the phenomenon of passivation of the electrode plate caused by the adhesion of organic matter. In the secondary treatment unit, the tiny bubbles generated by the bottom aeration have a cleaning effect on the microfiltration membrane group. During cleaning and maintenance, the cleaning equipment can be used to pass the cleaning medium (water or gas) into the water vapor cleaning port, so as to clean the inner cavity of the secondary treatment box and its microfiltration membrane group;

[0029] 2. It can effectively remove oil, foamy organic matter and large suspended solids in sewage;

[0030] 3. Use microfiltration membrane groups to remove large particles of organic matter, bacteria and other pollutants in the water. At the same time, use a self-priming pump to lead the water in the secondary treatment tank back to the raw water collection area of ​​the primary treatment tank to reduce the pollutant concentration in the water and reduce the load of pollutant treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a system layout diagram of the present invention.

[0032] Figure 2 It is a schematic diagram of a primary processing unit of the present invention.

[0033] Figure 3 It is a schematic diagram of the secondary processing unit of the present invention.

[0034] In the figure:

[0035] 1-primary treatment unit, 101-primary treatment tank, 101a-raw water collection area, 101b-primary upper liquid collection area, 101c-upper liquid storage chamber, 102-primary metering pump, 103-electrode plate group, 104-first aeration port, 105-first dosing port, 106-first mud discharge port, 107-first demister, 108-demister layer, 109-water storage tank, 109a-first cavity, 109b-second cavity;

[0036] 2-secondary treatment unit, 201-secondary metering pump, 202-secondary treatment box, 202a-secondary collection area, 202b-upper liquid collecting chamber, 203-second aeration port, 204-second dosing port, 205-second mud discharge port, 206-microfiltration membrane group, 207-self-priming pump, 208-second demister, 209-water vapor cleaning port, 210-overflow liquid collecting bin, 210a-bottom water outlet, 211-side reflux port. DETAILED DESCRIPTION

[0037] The following is combined with Figure 1-3 The present invention is further illustrated with reference to the accompanying drawings and specific embodiments.

[0038] like Figure 1-2 As shown, an enhanced electric flocculation coupling reaction device for heavy metal wastewater treatment includes a primary treatment unit 1, and the primary treatment unit 1 includes a primary treatment box 101, a primary metering pump 102, and an electrode plate group 103.

[0039] The bottom of the inner cavity of the primary treatment box 101 is set as a raw water collection area 101a, and the infusion end of the primary metering pump 102 is connected to the raw water collection area 101a.

[0040] The electrode plate group 103 is arranged in the inner cavity of the primary treatment box 101 and is located above the raw water collection area 101a. The electrode plate group 103 includes a plurality of negative electrode plates and a plurality of positive electrode plates. Both the negative electrode plates and the positive electrode plates are connected to a power supply. The plurality of negative electrode plates and the plurality of positive electrode plates are arranged alternately, and any two adjacent electrode plates are both positive and negative electrodes.

[0041] A first demister 107 is installed on the top wall of the primary treatment box 101 , and the filtering part of the first demister 107 is located at the top of the inner cavity of the primary treatment box 101 .

[0042] The inner cavity of the above-mentioned primary treatment box 101 is provided with a primary upper liquid collecting area 101b located above the electrode plate group 103, and is also provided with an upper liquid storage chamber 101c parallel to the primary upper liquid collecting area 101b. The upper side of the primary upper liquid collecting area 101b is provided with an overflow channel connected to the upper side of the upper liquid storage chamber 101c, and the filtering part of the first demister 107 is located in the overflow channel of the primary upper liquid collecting area 101b.

[0043] The first aeration port 104 connected to the raw water collection area 101a is provided at the bottom of the primary treatment tank 101. The first aeration port 104 faces the electrode plate group 103 upwards. Air is introduced into the first aeration port 104 by an aeration device for aeration treatment. The first sludge discharge port 106 for discharging sludge is provided at the bottom of the primary treatment tank 101. The first dosing port 105 connected to the raw water collection area 101a is provided at the bottom of the primary treatment tank 101. Reagents are added or the pH value is adjusted through the first dosing port 105.

[0044] The upper liquid storage chamber 101c is provided with a defoaming layer 108 for filtering out floating foam, which is located below the overflow channel of the first-level upper liquid collecting area 101b. The defoaming layer 108 can be removed for cleaning. A water storage tank 109 is also provided on the outer wall of the first-level treatment tank 101. The water storage tank 109 is provided with a first cavity 109a and a second cavity 109b arranged side by side on the left and right. The upper liquid storage chamber 101c has an overflow port located below the defoaming layer 108 and connected to the upper side of the first cavity 109a. An overflow channel from the first cavity 109a to the second cavity 109b is provided in the water storage tank 109.

[0045] In the primary treatment unit 1, the tiny bubbles generated by the bottom aeration clean the electrode plates, reducing the phenomenon of electrode plate passivation caused by the adhesion of organic matter.

[0046] Combination Figure 1 , 3 As shown, the reaction device is also provided with a secondary treatment unit 2, and the secondary treatment unit 2 comprises:

[0047] A secondary treatment box 202, wherein a solid-liquid separation component is provided in the inner cavity of the secondary treatment box 202, an area below the solid-liquid separation component in the inner cavity of the secondary treatment box 202 is set as a secondary collection area 202a, and an area above the solid-liquid separation component is set as an upper liquid collection area 202b, and an overflow port is provided on the upper side of the secondary treatment box 202;

[0048] A secondary metering pump 201, wherein the suction end of the secondary metering pump 201 is connected to the bottom of the second cavity 109b of the water storage tank 109, and the water outlet end of the secondary metering pump 201 is connected to the secondary collection area 202a;

[0049] A second demister 208 for filtering out the floating foam of the overflow water in the secondary treatment tank 202, wherein the second demister 208 is disposed on the top wall of the secondary treatment tank 202 and the filtering part thereof is located at the top of the inner cavity of the secondary treatment tank 202;

[0050] The overflow liquid collecting bin 210 is fixedly arranged on the outer wall of the secondary treatment box 202. The upper side of the overflow liquid collecting bin 210 is connected with the upper overflow port of the secondary treatment box 202. The bottom of the overflow liquid collecting bin 210 is provided with a bottom water outlet 210a.

[0051] The solid-liquid separation components in the secondary treatment box 202 are configured as two groups of microfiltration membrane groups 206 distributed vertically, and each microfiltration membrane group 206 is composed of a plurality of microfiltration membranes arranged at intervals in the horizontal direction and close to each other.

[0052] The bottom of the secondary treatment box 202 is provided with a second aeration port 203 connected to the secondary collection area 202a and facing the microfiltration membrane group 206. Under aeration conditions, negative pressure can be formed between the membranes to drive the solid-liquid separation phenomenon in the water body.

[0053] The above-mentioned secondary treatment unit 2 is also provided with a self-priming pump 207. The water suction end of the self-priming pump 207 is connected with the water filtration layer inside each membrane through the central water pipe of the microfiltration membrane group 206 located in the inner cavity of the secondary treatment box 202. The water filtration layer is formed by two organic membranes that are reversely welded outward. The water outlet end of the self-priming pump 207 is divided into two outputs, and one of the output pipelines is connected with the inner cavity of the primary treatment box 101 through the first dosing port 105.

[0054] The top of the secondary treatment box 202 is provided with a plurality of water vapor cleaning ports 209 connected to the cleaning equipment. The water vapor cleaning ports 209 are connected to the inner cavity of the secondary treatment box 202. During cleaning and maintenance, the cleaning equipment outputs the cleaning medium into the secondary treatment box 202 through the water vapor cleaning ports 209 so as to flush and clean the interior of the secondary treatment box 202 and also clean the scale on the microfiltration membrane group 206.

[0055] The side wall of the above-mentioned secondary treatment box 202 is provided with at least one side return port 211, and the position of the side return port 211 is lower than the position of the second demister 208. The side return port 211 connects the overflow liquid collecting bin 210 and the upper liquid collecting area 202b to drain part of the water in the overflow liquid collecting bin 210 into the upper liquid collecting area 202b.

[0056] The bottom of the secondary treatment tank 202 is provided with a second sludge discharge port 205 for discharging sludge. The bottom of the secondary treatment tank 202 is provided with a second drug addition port 204 communicating with the secondary collection area 202a for adding reagents or adjusting the pH value.

[0057] In the secondary treatment unit 2, a microfiltration membrane group 206 is used to remove large particles of organic matter, bacteria and other pollutants in the water. At the same time, a self-priming pump 207 is used to lead the water in the secondary treatment tank 202 back to the raw water collection area 101a of the primary treatment tank 101, thereby reducing the pollutant concentration in the water and alleviating the load of pollutant treatment.

[0058] Combination Figure 1-3 As shown, the working process of this embodiment is roughly as follows: the primary metering pump 102 pumps the raw wastewater into the raw water collection area 101a, and the drug is added to the raw water collection area 101a through the first drug adding port 105. Under the condition of aeration, the raw water rises and contacts the electrode plate, and an electric flocculation reaction occurs. The floccules generated under the action of aeration float to the primary upper liquid collection area 101b, and when flowing through the first demister 107, the floccules are filtered out by the first demister 107. At the same time, the tiny bubbles in the water body can also remove the oil in the sewage. Then the water body passes downward through the defoaming layer 108, and the defoaming layer 108 is used for secondary filtration and deposited in the upper liquid storage chamber 101c. The water overflowing from the upper liquid storage chamber 101c flows into the first cavity 109a of the water storage tank 109, and the water overflowing from the first cavity 109a flows into the second cavity 109b, thereby diluting the water body in the water storage tank 109.

[0059] The water in the second cavity 109b is pumped to the secondary collection area 202a of the secondary treatment box 202 by using the secondary metering pump 201. Under aeration conditions, the water rises and contacts the microfiltration membrane group 206. Under aeration conditions, a negative pressure can be formed between the membranes to drive the water to produce solid-liquid separation. When the water overflows from the upper liquid collecting area 202b, it is filtered again by the filtering effect of the second demister 208. Finally, the water overflows into the overflow liquid collecting bin 210 and the treated water is discharged through the bottom water outlet 210a. When the water is in the overflow liquid collecting bin 210, it can also flow back to the upper liquid collecting area 202b through the side reflux port 211 to undergo another defoaming process.

[0060] The defoamer or defoaming layer mentioned in this embodiment is a conventional structure with a filter screen, which can filter floating foam or flocculants in water.

[0061] The above are preferred embodiments of the present invention. A person skilled in the art may make various changes or improvements on this basis. Without departing from the general concept of the present invention, these changes or improvements should fall within the scope of protection required by the present invention.

Claims

1. An enhanced electro-flocculation coupling reaction device for heavy metal wastewater treatment, comprising a primary treatment unit (1), the primary treatment unit (1) comprising a primary treatment box (101), a primary metering pump (102), and an electrode plate group (103), the bottom of the inner cavity of the primary treatment box (101) being set as a raw water collection area (101a), the electrode plate group (103) being arranged in the inner cavity of the primary treatment box (101) and being located above the raw water collection area (101a), and the infusion end of the primary metering pump (102) being connected to the raw water collection area (101a); It is characterized in that A first demister (107) is installed on the top wall of the primary treatment box (101), and a filtering part of the first demister (107) is located at the top of the inner cavity of the primary treatment box (101); The first-level treatment box (101) has an inner cavity provided with a first-level upper liquid collecting area (101b) located above the electrode plate group (103), and also has an upper liquid storage chamber (101c) arranged side by side with the first-level upper liquid collecting area (101b); an overflow channel communicating with the upper side of the upper liquid storage chamber (101c) is provided on the upper side of the first-level upper liquid collecting area (101b); and the filtering part of the first demister (107) is located in the overflow channel of the first-level upper liquid collecting area (101b); The bottom of the primary treatment box (101) is provided with a first aeration port (104) connected to the raw water collection area (101a), and the first aeration port (104) faces the electrode plate group (103) upwards; The upper liquid storage chamber (101c) is provided with a defoaming layer (108) located below the overflow channel of the primary upper liquid collecting area (101b) and used for filtering out floating foam, and the outer side wall of the primary treatment box (101) is also provided with a water storage tank (109); The reaction device further comprises a secondary treatment unit (2), the secondary treatment unit (2) comprising a secondary treatment box (202), a solid-liquid separation component being provided in the inner cavity of the secondary treatment box (202), an area below the solid-liquid separation component in the inner cavity of the secondary treatment box (202) being set as a secondary collection area (202a), an area above the solid-liquid separation component being set as an upper liquid collection area (202b), and an overflow port being provided on the upper side of the secondary treatment box (202); The top of the secondary processing box (202) is provided with a plurality of water vapor cleaning ports (209) connected to cleaning equipment, and the water vapor cleaning ports (209) are connected to the inner cavity of the secondary processing box (202); The side wall of the secondary treatment box (202) is provided with at least one side return port (211), the position of the side return port (211) being lower than the position of the second demister (208), and the side return port (211) being connected to the overflow liquid collecting bin (210) and the upper liquid collecting area (202b), so as to drain part of the water in the overflow liquid collecting bin (210) into the upper liquid collecting area (202b).

2. The enhanced electro-flocculation coupled reaction device for heavy metal wastewater treatment according to claim 1 is characterized in that: The water storage tank (109) is provided with a first cavity (109a) and a second cavity (109b) arranged side by side on the left and right; the upper liquid storage chamber (101c) has an overflow port located below the defoaming layer (108) and communicating with the upper side of the first cavity (109a); and an overflow channel leading from the first cavity (109a) to the second cavity (109b) is provided in the water storage tank (109).

3. The enhanced electro-flocculation coupled reaction device for heavy metal wastewater treatment according to claim 2 is characterized in that: The secondary processing unit (2) comprises: A secondary metering pump (201), wherein the suction end of the secondary metering pump (201) is connected to the bottom of the second cavity (109b) of the water storage tank (109), and the water outlet end of the secondary metering pump (201) is connected to the secondary collection area (202a); A second demister (208) for filtering out floating foam in overflow water in the secondary treatment tank (202), the second demister (208) being arranged on the top wall of the secondary treatment tank (202) and having a filtering portion located at the top of the inner cavity of the secondary treatment tank (202); An overflow liquid collecting bin (210) is fixedly arranged on the outer side wall of the secondary treatment box (202), the upper side of the overflow liquid collecting bin (210) is connected to the upper overflow port of the secondary treatment box (202), and the bottom of the overflow liquid collecting bin (210) is provided with a bottom water outlet (210a).

4. The enhanced electro-flocculation coupled reaction device for heavy metal wastewater treatment according to claim 3 is characterized in that: The solid-liquid separation component in the secondary treatment box (202) is configured as at least one group of microfiltration membrane groups (206), wherein the microfiltration membrane group (206) is composed of a plurality of microfiltration membranes that are spaced apart and close to each other in a horizontal direction.

5. The enhanced electro-flocculation coupled reaction device for heavy metal wastewater treatment according to claim 4 is characterized in that: The bottom of the secondary treatment box (202) is provided with a second aeration port (203) which is connected to the secondary collection area (202a) and faces the microfiltration membrane group (206) upwards.

6. The enhanced electro-flocculation coupled reaction device for heavy metal wastewater treatment according to claim 4 is characterized in that: The secondary treatment unit (2) is further provided with a self-priming pump (207), the water suction end of the self-priming pump (207) being connected to the water outlet end of the microfiltration membrane group (206) in the inner cavity of the secondary treatment box (202); The bottom of the primary treatment tank (101) is provided with a first drug addition port (105) communicating with the raw water collection area (101a); The water outlet of the self-priming pump (207) is divided into at least two outputs, and one of the output pipelines is connected to the inner cavity of the primary treatment box (101) through the first drug adding port (105).

7. The enhanced electro-flocculation coupled reaction device for heavy metal wastewater treatment according to claim 3 is characterized in that: The bottom of the primary treatment tank (101) is provided with a first mud discharge port (106) for discharging sludge, and the bottom of the secondary treatment tank (202) is provided with a second mud discharge port (205) for discharging sludge.

8. The enhanced electro-flocculation coupled reaction device for heavy metal wastewater treatment according to claim 3 is characterized in that: The bottom of the secondary treatment box (202) is provided with a second drug addition port (204) communicating with the secondary collection area (202a).

Images