Gray water pumping system for restaurant effluent
Restaurant kitchens, hotels, canteens and catering services always require the installation of a grease trap before discharging to public sewerage system. As a practice, whenever possible, it is advisable to install, immediately downstream the gray drainage column, a grease separator to avoid the decreasing of the temperature inside pipes, which causes fat thickening and grease accumulation with the result of occlusion problems and malfunctions.
If it is not possible to install a grease trap, as mentioned above, due to lack of space or quote differences (kitchen may often be located under the ground level), a technically more complex solution is needed, based on the experience gained over years by technicians and engineers of AZU Water who believes they have found an efficient solution to solve these types of issues.
Problem description
In some cases, just because the kitchen is below the ground level and there isn’t a sufficient slope to discharge into the sewer, we can choose a simple lifting station, often in concrete, with all difficulties related to work in tight spaces with hight weight tank.
The lifting station has a high buildup of surface grease that creates considerable problems to pumps and floaters.
The main cause is the lack of a properly dimensioned degreaser.
Plant Solutions
For light lifting stations that do not require high excavation depth and with high resistance tanks, please check at: ELESTATION ORANGE product.
In these cases, AZU Water recommends the grease trap GREASE ORANGE made by polyethylene: they require a small excavation depth due to their shape and they can be placed even in the presence of groundwater without the concrete reinforcement.
SOLUTION
To avoid these problem, AZU Water offers to install a water tank, to collect wastewater coming from dishwasher and kitchen taps, equipped with an external pump necessary to forward to the grease trap.
In some cases, where there are already unused tanks such as septic tanks it is possible to convert tanks in fat separators.
AZU Water believes, where possible, it is useful to reuse existing tanks, if they have a good state of preservation and have sufficient volume, it is possible to retrieve the existing facilities so as to minimize the excavation interventions for the end user.
All this can be done, only if the choice does not affect the good functioning of the plant and the final characteristics of the effluent.
For example, a too small volume of the degreaser require frequent maintenance (desludging) resulting in increased operating costs (to be considered for the entire life of the plant) is often much greater than costs for a new grease trap installation, even in consideration of the location of the kitchen and the complexity to achieve the desludging area.
AZU Water in this case offers a tailor-made solution for the accumulation and recovery of saponous water from the dishwasher and from the polypropylene sink, 10 mm thickness realized and welded according to the dimensions available in the kitchen.
The storage tank is equipped with anti-depressant covers and gaskets in EPDM and the specific unloading lugs for the elements in the kitchen.
The pump choice is a self-priming centrifugal pump with open impeller that was chosen because it suitable to work at maximum temperatures up to 110 ° C.
In fact, despite an accumulation basin that can eventually equalize the temperature of the effluent in exit, it is necessary to choose materials that can resist the direct unloading a dishwasher and sinks that can reach 80-90 ° C.
The choice of an external self priming pump is related to the convenience in maintenance and replacement which, for obvious reasons is less problematic.
Usually the advantage of a submersible pump is the cooling system, which could not be guaranteed in this case due to high temperatures discharged influent (dishwasher).
The choice is an impeller self priming pump with a free passage of 16 mm with the parts in contact with the liquid realized in AISI 304 with mechanical seals in silicon carbide and FKM (Viton).
Particular attention should be placed on the choice of the seals always on mechanical properties of high temperature of discharged wastewater.
The system is equipped with particularly electronic level regulator (IP68 degree of protection), which allows the operation even in the presence of grease, unlike normal floating level regulators.
To facilitate maintenance, the plant is equipped with a rotating PVC head for pressure wash the tank which must be connected to the hot water line.
To overcome the high-temperature reverse problem, AZU Water has decided to equip the small gray water heater with a heating coil and a thermostat to prevent the fat from solidifying inside the storage volume during the unsed period (night) creating unpleasant occlusions.
The system is entirely managed by an electrical control panel equipped with a PLC.
AZU Water considers the automatic management of sewage systems really important in order to leave the client free in carrying out his business, avoiding that plant management seriously affects his professional performance and paradoxically does not become his main activity. In fact, installing a technically unmanaged and poor quality solutions, the restaurant manager is likely to be constantly involved in solving problems related to wastewater as much as satisfiting their customers.
In the plant management it is very important to minimize human error that can be achived with a programmable logic controller: in fact it has also the advantage of being able to be integrated with malfunction alarm devices, either locally or remotely (GSM unit for sms), allowing a timely maintenance operation with the consequent minimization of user service inefficiency.
AZU Water and its technicians are ready to provide and install custom solutions for the management of gray waters drainage.
AZU Water is available to offer technical solutions; for more information please do not hesitate to contact our customer service CONTACT.
