CN110627259A - A purification method for washing sewage of concrete mixer truck - Google Patents

Abstract

A purification method for cleaning sewage of a concrete mixing truck belongs to the technical field of sewage treatment. Step 1, cleaning a transport vehicle: pumping clean water in a circulating water tank by a car washing pump for cleaning; step 2, recycling sand: sorting the cleaning sewage by adopting a sand-stone separator, and returning the sorted sand and stone aggregate to a material warehouse for recycling; step 3, pre-settling muddy water: conveying muddy water discharged by the sand-stone separator to a slope pre-settling tank for pre-settling and coarse-separating, conveying sediments to the sand-stone separator for backwashing, and allowing overflow of the pre-settling tank to enter a muddy water buffer tank; step 4, recycling mud water: directly conveying part of muddy water in the muddy water buffer pool to a stirring building for utilization; step 5, solid-liquid separation: the scheme of concentration plus filter pressing or direct filter pressing can be adopted to implement solid-liquid separation; step 6, filter pressing storage and transportation: the filtrate of the filter press is conveyed to a circulating water pool for reuse, and the filter cake is centrally stored and transported. The advantages are that: the method is simple, improves the circulating water quality, avoids the occurrence of silting, saves resources and has good use effect.

Description

A purification method for washing sewage of concrete mixer truck

technical field

The invention relates to the technical field of sewage treatment, in particular to a method for purifying sewage from a concrete mixer truck.

Background technique

Concrete mixer trucks are the primary means of transportation for commercial concrete. In order to avoid problems caused by the solidification of residual concrete in the storage tank of the concrete mixer truck, it is necessary to clean the residual concrete in the storage tank of the concrete mixer truck in a timely manner. The sewage generated during the cleaning process contains hydraulic materials such as sand, cement, fly ash, mineral powder, and concrete admixtures, which pollute the environment and are not conducive to reuse. Therefore, the cleaning water of concrete mixer trucks must be purified. deal with.

At present, in the purification treatment of the cleaning water of concrete mixer trucks, the simple multi-stage slope sedimentation tank process is mostly used to purify the car wash sewage of concrete mixer trucks. question. During the concentrated high-density car washing period, the instantaneous flow of car washing sewage is large and the solid concentration is high, which seriously affects the clarification effect of the multi-stage sedimentation tank, and the quality of circulating water cannot be guaranteed. If the sediment in the multi-stage sedimentation tank is not cleaned in time, the upper water layer of the sedimentation tank will be too shallow, the water flow velocity will be high, and the particles will be difficult to settle. The concentration of overflow muddy water will increase, the quality of circulating water will deteriorate, and production will be affected. The sediment excavated from the sedimentation tank has high moisture content and is difficult to transport, store and utilize.

Contents of the invention

Technical problem: The purpose of this invention is to overcome the deficiencies in the prior art and provide a concrete mixer truck with simple method, small footprint, improved circulating water quality, avoiding clogging, resource saving, and good use effect Purification method of cleaning sewage.

Technical solution: The purpose of the present invention is achieved in this way: the steps of the cleaning water purification process for concrete mixer trucks are as follows:

Step 1, transport vehicle cleaning: use the car wash pump to extract the sediment water from the circulating pool for cleaning;

Step 2, sand and gravel recycling: use a sand and gravel separator to sort the cleaning sewage, and return the sorted sand and stone aggregates to the material warehouse for reuse;

Step 3, pre-sedimentation of mud and water: the mud water discharged from the sand separator is transported to the slope pre-sedimentation tank for pre-sedimentation and coarse separation, the sediment is transported to the sand and gravel separator for backwashing, and the overflow of the pre-settling tank enters the mud water buffer tank;

Step 4, reuse of muddy water: according to the production situation of the mixing building, part of the muddy water in the muddy water buffer pool is directly transported to the mixing building for use as appropriate;

Step 5, solid-liquid separation: solid-liquid separation can be implemented by means of concentration + pressure filtration or direct pressure filtration;

Step 6, storage and transportation of filter press: the filtrate of the filter press is transported to the circulating pool for reuse, and the filter cake is stored in a centralized manner and transported abroad.

In step 1, cleaning of the transport vehicle: use the car wash pump to extract clean water from the circulating pool to clean the concrete mixing transport vehicle, and replenish the circulating pool with fresh water from the supplementary pool in due course.

In the step 2, sand and gravel recovery: the car wash sewage is discharged into the feed tank of the sand and gravel separator, and the sand and gravel separator is used to separate the sand, stone and muddy water in the car wash sewage, and the sand selected by the sand and gravel separator Stone aggregates are returned to the material warehouse for reuse, reducing waste of resources.

In step 3, pre-sedimentation of mud and water: the mud water discharged from the sand separator is transported to the slope pre-sedimentation tank for pre-sedimentation and separation, and the sediment in the pre-settling tank is transported to the sand and gravel separator for backwashing, and the recovered sand and gravel The sand and gravel particles lost due to the coarse running of the separator not only reduce the waste of sand and gravel resources, but also reduce the adverse effects of coarse grains on subsequent operations; Multi-stage pre-sedimentation tank.

In step 4, muddy water reuse: according to the production situation of the mixing building, under the premise of not affecting the quality of the concrete, part of the muddy water in the muddy water buffer pool is transported to the mixing building as appropriate, so as to reduce the workload of subsequent muddy water treatment. Waste discharge and fresh water consumption of the mixing plant.

In step 5, solid-liquid separation: Two solid-liquid separation schemes can be adopted: concentration + pressure filtration or direct pressure filtration:

(1) Concentration + filter press solid-liquid separation scheme: the sludge is sent from the bottom of the mud-water buffer tank to the concentration device through the feed pump for clarification and concentration; the concentration device adds coagulation to the concentration device through the dosing device as needed agent to improve the effect of sludge concentration and clarification. The overflow water from the concentration device is transported to the circulating pool for reuse; the underflow mud from the concentration device enters the mixing tank through the underflow pump, and the slurry is mixed in the mixing tank, and pumped through the press filter. into the filter press;

The concentration device selected according to the site space and water volume is a high-efficiency thickener, a deep cone concentration tank or a hydrocyclone;

(2) Direct filter separation scheme: When the site space is limited or the water volume is small, it is difficult or unnecessary to install a thickening device, the mud in the mud buffer tank is directly transported to the mixing tank through the bottom flow pump, and the filter press feed pump directly The mixing tank mud is sent to the filter press.

In step 6, filter press storage and transportation: the mud in the mixing tank is sent to the filter press, and the filter press operation is performed on the mud, and the filtrate of the filter press is transported to the circulating pool for reuse, and the filter cake can be stored or recycled at a selected site use.

Beneficial effects: due to the adoption of the above scheme, the present invention proposes a complete, reliable, Flexible and efficient purification process, strong system adaptability, high quality of circulating water, less solid waste discharge, and low moisture content of mud cake can provide technical support for commercial concrete mixing plants to achieve clean production and build green mixing plants.

Due to the high alkalinity, high salinity, and high hardness of the car wash water, it is easy to precipitate and scale on the surface of the water passing facilities, and the cement and fly ash in the car wash water are hydraulic materials, which have the phenomenon of consolidation and hanging on the wall, so Concentration equipment with simple structure and small solid-liquid contact surface should be used, and the residence time of mud in the concentrator should not be too long. High-efficiency concentrators, deep cone concentrators, hydrocyclones, etc. can be selected according to the site space and water volume. equipment.

The cleaning sewage purification process of concrete mixer truck proposed in the present invention is transformed on the basis of the original process, forming a set of more complete, reliable, flexible and efficient cleaning sewage purification process method of concrete mixer truck. The process system has strong adaptability, high circulating water quality, less solid waste discharge, and low moisture content of mud cake, which is convenient for transportation, storage and utilization. Concrete mixer truck cleaning sewage has a high solid content and contains hydraulic materials and concrete admixtures. In order to save resources and protect the environment, it needs to be treated and purified. The technical problem to be solved by the present invention is to provide a complete, flexible, reliable and efficient process method for cleaning sewage from concrete mixer trucks.

The method is simple, occupies a small area, improves circulating water quality, avoids clogging, saves resources, and has good use effects, thereby achieving the purpose of the invention.

Description of drawings

Fig. 1 is a flow chart of the method of the present invention.

Fig. 2 is a flow chart of the method of Embodiment 1 of the present invention.

Fig. 3 is a flow chart of the method of Embodiment 2 of the present invention.

Detailed ways

The steps of the cleaning water purification method for concrete mixer truck of the present invention are as follows:

Step 1, transport vehicle cleaning: use the car wash pump to pump clean water from the circulating pool for cleaning;

Step 2, sand and gravel recycling: use a sand and gravel separator to sort the cleaning sewage, and return the sorted sand and stone aggregates to the material warehouse for reuse;

Step 3, pre-sedimentation of mud and water: the mud water discharged from the sand separator is transported to the slope pre-sedimentation tank for pre-sedimentation and coarse separation, the sediment is transported to the sand and gravel separator for backwashing, and the overflow of the pre-settling tank enters the mud water buffer tank;

Step 4, reuse of muddy water: according to the production situation of the mixing building, part of the muddy water in the muddy water buffer pool is directly transported to the mixing building for use as appropriate;

Step 5, solid-liquid separation: solid-liquid separation can be implemented by means of concentration + pressure filtration or direct pressure filtration;

Step 6, storage and transportation of filter press: the filtrate of the filter press is transported to the circulating pool for reuse, and the filter cake is stored in a centralized manner and transported abroad.

In step 1, cleaning of the transport vehicle: use the car wash pump to extract clean water from the circulating pool to clean the concrete mixing transport vehicle, and replenish the circulating pool with fresh water from the supplementary pool in due course.

In the step 2, sand and gravel recovery: the car wash sewage is discharged into the feed tank of the sand and gravel separator, and the sand and gravel separator is used to separate the sand, stone and muddy water in the car wash sewage, and the sand selected by the sand and gravel separator Stone aggregates are returned to the material warehouse for reuse, reducing waste of resources.

In step 3, pre-sedimentation of mud and water: the mud water discharged from the sand separator is transported to the slope pre-sedimentation tank for pre-sedimentation and separation, and the sediment in the pre-settling tank is transported to the sand and gravel separator for backwashing, and the recovered sand and gravel The sand and gravel particles lost due to the coarse running of the separator not only reduce the waste of sand and gravel resources, but also reduce the adverse effects of coarse grains on subsequent operations; Multi-stage pre-sedimentation tank.

In step 4, muddy water reuse: according to the production situation of the mixing building, under the premise of not affecting the quality of the concrete, part of the muddy water in the muddy water buffer pool is transported to the mixing building as appropriate, so as to reduce the workload of subsequent muddy water treatment. Waste discharge and fresh water consumption of the mixing plant.

In step 5, solid-liquid separation: Two solid-liquid separation schemes can be adopted: concentration + pressure filtration or direct pressure filtration:

(1) Concentration + filter press solid-liquid separation scheme: the sludge is sent from the bottom of the mud-water buffer tank to the concentration device through the feed pump for clarification and concentration; the concentration device adds coagulation to the concentration device through the dosing device as needed agent to improve the effect of sludge concentration and clarification. The overflow water from the concentration device is transported to the circulating pool for reuse; the underflow mud from the concentration device enters the mixing tank through the underflow pump, and the slurry is mixed in the mixing tank, and pumped through the press filter. into the filter press;

The concentration device selected according to the site space and water volume is a high-efficiency thickener, a deep cone concentration tank or a hydrocyclone;

(2) Direct filter separation scheme: When the site space is limited or the water volume is small, it is difficult or unnecessary to install a thickening device, the mud in the mud buffer tank is directly transported to the mixing tank through the bottom flow pump, and the filter press feed pump directly The mixing tank mud is sent to the filter press.

In step 6, filter press storage and transportation: the mud in the mixing tank is sent to the filter press, and the filter press operation is performed on the mud, and the filtrate of the filter press is transported to the circulating pool for reuse, and the filter cake can be stored or recycled at a selected site use.

The present invention will be further described below in conjunction with the embodiment in the accompanying drawings:

Embodiment 1: A method for purifying cleaning water of a concrete mixer truck according to the present invention, as shown in FIG. 2 .

Step 1, cleaning of the transport vehicle: pump clean water from the circulating pool to clean the concrete mixer transport vehicle, and replenish the circulating pool with fresh water from the supplementary pool in due course.

Step 2, gravel recovery: car washing sewage is discharged into the feed tank of the sand and gravel separator, and the sand, stone and mud in the car washing sewage are separated by the sand and gravel separator, and the sand and gravel aggregate selected by the sand and gravel separator is returned to the material warehouse Reuse.

Step 3, pre-sedimentation of mud and water: use the 2-stage slope sedimentation tank set up in the original process of the mixing station as the pre-settling tank, and transport the muddy water discharged from the sand and gravel separator to the pre-settling tank, and the sediment at the bottom of the No. 1 pre-settling tank is regularly Clean up to ensure the height of the sedimentation water layer. The sediment cleaned out of the No. 1 pre-sedimentation tank contains the coarse sand particles from the sand separator, and the sediment is transported back to the sand separator to recover the coarse particles. The overflow of the No. 1 pre-sedimentation tank flows into the No. 2 pre-sedimentation tank, and the sediment at the bottom of the No. 2 pre-sedimentation tank is cleaned up in time to ensure a sufficient height of the sedimentation water layer.

Step 4, reuse of muddy water: the overflow muddy water of No. 2 pre-sedimentation tank enters the muddy water mixing buffer tank, according to the production situation of the mixing building, and under the premise of not affecting the quality of the concrete, part of the muddy water in the muddy water buffer tank is transported to the mixing building for use as appropriate , This will help reduce the workload of subsequent muddy water treatment, solid waste discharge and clean water consumption in the mixing plant.

Step 5, muddy water concentration: the muddy water in the stirring buffer tank is pumped to the thickening device for concentration and clarification. In this embodiment, the concentrating device uses a cone-shaped concentrating tank, and an automatic dosing machine is used to add an appropriate amount of flocculant as appropriate, and the overflow of the concentrating device is automatically transported to the circulating water pool through the overflow pipe. The concentration of overflow water is less than 1.0g/L, which fully meets the water quality requirements of mixing plant production and car washing. The underflow mud from the thickening device enters the feeding mixing tank of the filter press for slurry mixing.

Step 6, filter press storage and transportation: the filter press feed mixing tank is stirred and slurried, filter aid is added to improve the filtration effect, and the filter press feed pump is used to transport the material to the plate and frame filter press for press filtration. The filtrate of the filter press enters the circulating water tank for recycling, and the water content of the mud cake filtered out by the press is below 25%, which is easy to transport, store and utilize.

Embodiment 2: A method for purifying cleaning water of a concrete mixer truck according to the present invention, as shown in FIG. 3 .

Step 1, cleaning of the transport vehicle: pump clean water from the circulating pool to clean the concrete mixer transport vehicle, and replenish the circulating pool with fresh water from the supplementary pool in due course.

Step 2, gravel recovery: car washing sewage is discharged into the feed tank of the sand and gravel separator, and the sand, stone and mud in the car washing sewage are separated by the sand and gravel separator, and the sand and gravel aggregate selected by the sand and gravel separator is returned to the material warehouse Reuse.

Step 3, pre-sedimentation of muddy water: the muddy water discharged from the sand separator is transported to the slope pre-sedimentation tank for pre-sedimentation and coarse separation, and the sediment in the pre-settling tank is transported to the sand separator for backwashing, and the lost sand particles are recovered. The waste of sand and gravel resources is reduced, and the adverse effect of coarse particles on subsequent operations is reduced; the overflow of the pre-sedimentation tank enters the muddy water buffer tank, and one-stage or multi-stage pre-sedimentation tanks are set depending on the space of the site.

Step 4, reuse of muddy water: according to the production situation of the mixing building, without affecting the quality of the concrete, part of the muddy water in the muddy water buffer pool is transported to the mixing building as appropriate, so as to reduce the workload of subsequent muddy water treatment, solid waste discharge and The clean water consumption of the mixing tower.

Step 5, solid-liquid separation: when the site space is limited or the water volume is small, it is difficult or unnecessary to install a thickening device, the mud in the mud-water buffer tank is directly transported to the mixing tank through the underflow pump, and the filter press feeding pump directly transfers the mud to the mixing tank. The barrel mud is sent to the filter press.

Step 6, filter press storage and transportation: the filter press feed mixing tank is stirred and slurried, filter aid is added to improve the filtration effect, and the filter press feed pump is used to transport the material to the plate and frame filter press for press filtration. The filtrate of the filter press enters the circulating water tank for recycling, and the water content of the mud cake filtered out by the press is below 25%, which is easy to transport, store and utilize.

Claims (8)

1. A purification method of cleaning sewage of a concrete mixing transport vehicle is characterized by comprising the following steps: the cleaning water purification process method of the concrete mixing transport vehicle comprises the following steps:

step 1, cleaning a transport vehicle: pumping clean water in a circulating water tank by a car washing pump for cleaning;

step 2, recycling sand: sorting the cleaning sewage by adopting a sand-stone separator, and returning the sorted sand and stone aggregate to a material warehouse for recycling;

step 3, pre-settling muddy water: conveying muddy water discharged by the sand-stone separator to a slope pre-settling tank for pre-settling and coarse-separating, conveying sediments to the sand-stone separator for backwashing, and allowing overflow of the pre-settling tank to enter a muddy water buffer tank;

step 4, recycling mud water: according to the production condition of the mixing plant, directly conveying part of the muddy water in the muddy water buffer tank to the mixing plant for utilization as appropriate;

step 5, solid-liquid separation: the scheme of concentration plus filter pressing or direct filter pressing can be adopted to implement solid-liquid separation;

step 6, storage, transportation and reuse: the filtrate of the filter press is conveyed to a circulating water pool for reuse, and the filter cake is centrally stored and transported.

2. The method for purifying the concrete mixer truck washing wastewater according to claim 1, wherein the method comprises the following steps: in the step 1, the transport vehicle is cleaned: and (4) pumping clear water from the circulating water tank by using a vehicle washing pump, washing the concrete mixing transport vehicle, and timely supplementing the clear water for the circulating water tank from the supplementing water tank.

3. The method for purifying the concrete mixer truck washing wastewater according to claim 1, wherein the method comprises the following steps: in the step 2, sand and stone recovery: the carwash sewage is discharged into a sand-stone separator feed chute, the sand-stone separator is adopted to separate sand, stone and muddy water in the carwash sewage, and sand-stone aggregate selected by the sand-stone separator is returned to the material warehouse for recycling, so that resource waste is reduced.

4. The method for purifying the concrete mixer truck washing wastewater according to claim 1, wherein the method comprises the following steps: in the step 3, the muddy water is pre-precipitated: muddy water discharged by the sand-stone separator is conveyed to the slope pre-settling tank for pre-settling and coarse-separating, sediment in the pre-settling tank is conveyed to the sand-stone separator for backwashing, sand-stone particles lost due to coarse running of the sand-stone separator are recovered, waste of sand-stone resources is reduced, and adverse effects of coarse grains on subsequent operation are reduced; the overflow of the pre-settling tank enters a muddy water buffer tank, and one-stage or multi-stage pre-settling tanks are arranged in the field space.

5. The method for purifying the concrete mixer truck washing wastewater according to claim 1, wherein the method comprises the following steps: in the step 4, recycling the muddy water: according to the production condition of the mixing plant, on the premise of not influencing the concrete quality, part of muddy water in the muddy water buffer tank is conveyed to the mixing plant to be utilized according to the condition, so that the operation burden, the solid waste discharge amount and the clear water use amount of the mixing plant in the subsequent muddy water treatment are reduced.

6. The method for purifying the concrete mixer truck washing wastewater according to claim 1, wherein the method comprises the following steps: in the step 5, solid-liquid separation: a solid-liquid separation scheme of concentration and filter pressing is adopted;

concentration + filter pressing solid-liquid separation scheme: conveying the sludge from the bottom of the sludge-water buffer tank to a concentration device through a feeding pump for clarification and concentration; the concentration device adds coagulant into the concentration device through a dosing device according to the requirement, so that the sludge concentration and clarification effects are improved, and overflow clear water of the concentration device is conveyed to a circulating water tank for reuse; the underflow slurry of the concentration device enters a stirring barrel through an underflow pump, is subjected to slurry mixing in the stirring barrel, and is sent to a filter press through a filter pressing feeding pump;

the concentration device selected according to the field space and the water quantity is a high-efficiency concentrator, a deep cone concentration tank or a hydrocyclone.

7. The method for purifying the concrete mixer truck washing wastewater according to claim 1, wherein the method comprises the following steps: in the step 5, solid-liquid separation: a solid-liquid separation scheme of direct pressure filtration is adopted;

direct filter-pressing separation scheme: when the field space is limited or the water quantity is small, and a concentration device is difficult to or does not need to be arranged, the slurry in the slurry buffer tank is directly conveyed to the stirring barrel through the underflow pump, and the slurry in the stirring barrel is directly conveyed to the filter press by the filter press feeding pump.

8. The method for purifying the concrete mixer truck washing wastewater according to claim 1, wherein the method comprises the following steps: in the step 6, filter pressing storage and transportation: and (3) feeding the slurry in the stirring barrel into a filter press, carrying out filter pressing operation on the slurry, conveying the filtrate of the filter press to a circulating water tank for reuse, and carrying out site-selective stockpiling or resource utilization on the filter cake.